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AMERICAN 
JOURNAL OF SOCLENCE. 


Established by BENJAMIN SILLIMAN in 1818. 
EDITORS 


JAMES D. anp EDWARD 8S. DANA. 


ASSOCIATE EDITORS 
Proressors JOSIAH P. COOKE, GEORGE L. GOODALE 
and JOHN TROWBRIDGE, or Camsprinas. 


Prorressors H. A. NEWTON anp A. E. VERRILL, or 
New Haven, 


Proressor GEORGE F. BARKER, or Pumapeputa. 


THIRD SERIES. 


VOL. XLIV._[WHOLE NUMBER, CXLIV.] 


Nos. 259—264. 


JULY TO DECEMBER, 1892. 


WITH TEN PLATES. 


NEW HAVEN, CONN.: J. D. & E. S. DANA 
Toya 


‘Puttle, Morehouse & Taylor, Printers, 371 State St., 


CONTENTS OF VOLUME XLIV. 


Number 259. 


Page. 


Art. I—The Change of Heat Conductivity on passing Iso- 


thermally from Solid to Liquid; by C. Barus---_---_--- 1 


IL.—Polybasite and Tennantite from the Mollie Gibson 


Mine in Aspen, Col.; by S. L. Prnrretp and S. H. 
JagHOAGE: OH ease ee Sina) a Wimeae Ne eae a take an ae ep till) 


IiI.—Post-Laramie Deposits of Colorado ; by W. Cross. __ 19 
TV.—Alkali-Metal Pentahalides; by H. L. Wetts and H. 


L. Wuereter. With their Crystallography ; by S312 
Reg RHINE USES TDD te eee Te eee) oc I Mk Ae heey ean 42 


V.-—Fossils in the “ Archean” rocks of Central Piedmont 


Vein cain ate Wa ONG EL. DAR MNON, yee ces eS eee as 50 


VI.—Notes on the Cambrian Rocks of Virginia and the 


Southern Appalachians; by C. D. WatcorTt.-.------- 52 


ViL—Synthesis of the minerals Crocoite and Phenico- 


ehijoiteR Diy © EU DEKING 2s 5 ep ie ea a coi ay 57 


VIIL—A Hint with respect to the Origin of Terraces in 


Glaciatedwinegions; “by, hs 8: DARR 2 72452 2 oe ese: 59 


I1X.—Occurrence of a Quartz Bowlder in the Sharon Coal of 


NortiiheasternOhiory by HORTON 257 ee) eee es 62 


X.—A Method of Increasing the Range of the Capillary 


Wleetrometer: by Jen VW HVIMORW) 5252 2828 ee eae 64 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics.—Luminosity of Coal Gas Flames, LEwss, 70.—Measure- 


ment of Osmotic Pressure, TAMMANN, 71.—Coefficient of Molecular Depression 
of Phenol, JUILLARD and CurcHop: Determination of Vapor Density under 
Diminished Pressure, ScHALL: Jahrbuch der Chemie, R. MryER, 72.—Chemical 
Calculations with explanatory notes, problems and answers, R. L. WHITELEY: 
Contributions to the knowledge of the discharge of the Ruhmkorff coil, Tom 
Motu, 73 —Photography in Colors, G. LIPPMANN, 75.— Dispersion of the 
Ultra. Red Rays, Dr. Rubens: Hlectrical Resistance of the Human Body, M. 
VON FREY, 76. 


Geology and Mineralogy.—History of Volcanic Action in the Area of the British 


Isles, A. GEIKIE. 76.—New Jersey Geological Report for 1891, J. C. Smock, 
77.-- Progress of the Kentucky Geological Survey, J. R. Procter: Kentucky 
Geological Survey: Report on Petroleum Natural Gas and Asphalt Rock of 
Western Kentucky, EH. ORTON: Geological Survey of Alabama, SmitH: Manning- 
ton Oil-field and the history of its development, I. C. WHITE, 78.—New Lower 
Silurian Lamellibranchiata, chiefly from Minnesota rocks, K. O. Ubrica: Der 
Peloponnes, Versuch einer Landeskunde auf geologischer Grundlage. nach 
Ergebnissen einiger Reisen. A. PHILIPPSON: Chiastolite in fossiliferous meta- 
morphic slates of Portugal J F. N DeEteapo: Striated Garnet from Buckfield, 
Maine. W. S. BayLey, 79.—Blowpipe Analysis, J. LANDAUER, 80. 


Miscellaneous Scientific Intelligence.—The Great Hurthquake of Japan, 1891, J. 


Minne and WK Burron, 80.—Congress of Mathematicians and Astronomers ; 
American Association, 81. 


Obituary —Lewis MorRIs RUTHERFURD, 82, 


iV CONTENTS. 


Number 260. 
; Z : Page. 
Art. XJ.—Relations between the Surface Tensions of Liq- 


uids and their Chemical Constitution; by C. E. Liyz- 

BARGER [soos Wee SSite ce lst eo eee hee eee 83 
XII.—Gold Deposit at Pine Hill, Cal; by W. Linperen.-. 92 
XIII.—New occurrence of Ptilolite; by W. Cross and L. G. 


HANGING 2 222s Selene PEBE oss dons ss Sea Sabe ssc s25% 96 
APPENDIX.—Note on the Constitution of Ptilolite and Mor- 
denite; (by ake WW @uaARKn =e cet t eae hte ieee yee ae 101 


XIV.—Separation of Magnesium Chloride from the Chlorides 
of Sodium and Potassium by means of Amyl Alcohol ; 


by RvB: Riges 2.028. Se eS eee 103 
XV.—Great Shear-zone near Avalanche Lake in the Adiron- 

dacks;by-J.ih. Kimmep )00 oo Se ee ee 109 
XV1—Herderite from Hebron, Maine; by H. L. Wetts 

and 8.1L, JRENPIELD 2 2022228 coe op Sas ee ee 114 
XVII.—Method for the Iodometric Determination of Ni- 

trates; by F. A. Goocu and H. W. Gruener_-.....--- 117 
XVIII.—Some Alkaline lodates; by H. L. WHEE er. 

With Crystallographic Notes; by 8. L. PEnFrenp -... 123 
XIX.—Development of the Brachiopoda. Part Il; by C. 

By Beecuer. (Wath Plates) 2225 2s es ete! 


XX.—Some Double Halides of Silver and the Alkali-metals; 
by H. L. Wetts and H. L. Wuerrrer. With their 
Crystallography; by ‘S: 1) Banrreip: 5224) 2> S22 ee 155 
XXI.—Cesium and Rubidium Chloraurates and Bromau- 
rates; by H. L. Weris and H. L. Warxter. With 


their Crystallography ; by S. L. Penrierp _-_-:------- 157 
X XII.—Preliminary Note of a New Meteorite from Kenton 
County, Kentucky; by H. Ii. Preston _--2 22292 2e2 163 
XXIII.—Additional observations on the Jura-Trias trap of 
the New Haven Region; by J. D. Dana ___.-_------ 165 
XXIV.—Notes on Mesozoic Vertebrate Fossils; by O. C. 
Marsx. (With Plates II-V..) 2°22 (hoes soy aes 171 


SCIENTIFIC INTELLIGENCE. 


Miscellaneous Scientific Intelligence—Natural Science: A monthly review of Scien- 
tific Progress: Catalogue of Scientific Papers (1874-1883): Experiments with 
alternate currents of high potential and high frequency, by Nikola Tesla, 170, 


CONTENTS. Vv 


Number 261. 


Art. XXV.—The Gulf of Mexico as a Measure of Isostasy ; ay 

LOY AG sed Kok Gr) aR pe ee ea et 17 
XXVI.—Persistence of Vision; by EH. 8. Furry .-.-.---_- 192 
XXVII.—Kilauea in April, 1892; by 8. E. BisHop..-..--- 207 
XXVIII.—The Devonian System of Eastern Pennsylvania; 

Diy C Sse eROSSR xcs O02. peepee er iain ie SOR rie 210 
XX1iX.—Cesium-Mercuric Halides, by EH. 1. Wrrns) 25522 221 
XXX.—Relations of the Laurentian and Huronian on the 

North Side of Lake Huron; by A. E. Bartow ------- 236 
XX XI.—Some Convenient Forms of Laboratory Apparatus ; 

yeep Ass GOOCH ts sif2h 0 2 cei LAS anes RN SUN AAU ee BU 239 
XXXII.—Note on the change of electric conductivity ob- 

served in rock magmas of different composition on pass- 

ing from liquid to solid; by Cart Barus and J. P. 

| GOTO ES SA oR Seis cen ge poe Cora CUE er mir sen eC NY No 242 
XX XIII.—Kstimation and Dehydration of Silver Oxide; 

Nyy pt CIA vege RIA eh fad ek ay a Aa A ee rey SH 249 


SCIENTIFIC INTELLIGENCH. 


Chemistry and Physics—Phenomena of Coal-dust Explosions, THORPE, 250.— 
Certain new forms of Carbon, Luzi, 251.—Quinite, the simplest Sugar of the 
Inosite group, BAEYER: Relation between the Color of Compounds and their 
Chemical Constitution, ScHUTzE, 252.—Free Hydroxylamine, LOBRY DE BRUYNE: 
Physical and chemical phenomena under the influence of very low temperatures, 
M. Raovun PIicTet, 253.—New method of determining the specific inductive 
capacity of a dielectric, F. T. Trou'ron and W. E. Linuy: Action of the Electric 
discharge on Gases and Vapors, C. LUDEKING: Ratio between the Electromagnetic 
and Electrostatic Units, M. H. ABranmAm: Influence of Electrification on Cloud 
Condensation, J. AITKEN, 254.—Thermal variation of viscosity and of electrolytic 
resistance, C. Barus: Outlines of Theoretical Chemistry, L. Meyer, 255.— 
Theoretical Mechanics, J. SPENCER: Negativ-Retouche nach Kunst- und Natur- 
gesetzen, HANS ARNOLD, 256. 


Geology and Mineralogy—Upraised Coral Islands off New Guinea, 256.—Origin of 
Igneous Rocks, J. P. Ippines, 257.—Bulletin of the Philosophical Society of 
Washington, Dutton on Isostasy, 258:—Siliceous bed consisting of Diatoms, 
Radiolarians and Sponge-spicules in New Zealand: Preliminary Catalogue of the 
systematic Collections in Economic Geology and Metallurgy in the U. 8. 
National Museum, F. P. Dewry: Paleontology of the Cretaceous formation on 
Staten Island, A. Hotick, 259.—Untersuchungen tiber fossile Hélzer Schwe- 
dens, H. ConweEntz: Penfieldite, a new species, F. A. GENTH, 260.—Brief 
notices of some recently described minerals, 261. 


Miscellaneous Scientific Intelligence—Transactions of the Wisconsin Academy of 
Sciences. Arts and Letters: Dictionary of Altitudes in the United States, H. 
GANNETT, 262, 


vi CONTENTS. 


Number 262. 
Art. XXXIV.—On a Color System; by O. N. Roop_.-__- 263 


XXXV.—An Ottrelite-bearing phase of a Metamorphic Con- 
glomerate in the Green Mountains; by C. L. Wuirrrir_ 270 


XXXVI.—Age-Coating in Incandescent Lamps; by E. L. 
INSCHOLS! U2 EATEN SE 0 iS UM a 277 


XXX VII.—Mica-peridotite from Kentucky; by J. S. DitLer 286 


XXXVIII.—Glaciation in the Finger-Lake region of New 
Mork: Sby a Sy uniNn © OL: Ngee eee eee ee ae ee 290 


XXXIX.—Certain Points in the Interaction of Potassium 
Permanganate and Sulphuric Acid; by F. A. Goocu 


and Hs: W:. DANNER)2 2. 224 Spa ce ee 
XL.—Crystallography of the Czsium-Mercuric Halides; by 

Sie PE NIUE De eye bib p ae gn epee Duels Dokly sae 311 
XLI.—Silver Hemisulphate; by M. C. Lea ._..---.------ 322 


ApPpENDIx.— X LI].—Restorations of Claosaurus and Cerato- 
saurus; by O. C. Marsu. (With Plates VI and VII). 343 


XLIII.—-Restoration of Mastodon Americanus, Cuvier ; by 
O2-Cr Marsu. (With: Plate Vill) 25) 222-2 ee 350 


SCIENTIFIC INTELLIGENCE. 


Geology—Geology of the Taylorville Region of California, J. S. DILLER: Jura and 
Trias at Taylorville, A. Hyatr: Geological Survey of the State of New York; 
Paleontology. Vol. VIII. J. Hatt, 330.—Report of the Arkansas Geological 
Survey for 1890, Vol. III, Whetstones and Novaculites of Arkansas, L. 8, 
GRISWOLD, 332.—Occurrence of- Artesian and other underground waters in 
Texas, ete. R. T. H1~L: Geological Society of America: Albirupean Studies, P. 
R. UHLER, 333.—Fossil Flora of the Bozeman Coal Field, F. H. KNOWLTON: 
Paléontologie Végétale (Ouvrages publiés en 1890), R. ZEILLER, 334.—Sylloge 
Fungorum Fossilium hucusque cognitorum, A. MESCHINELHI, 335.—Tronchi di 
Bennettitee dei Musei Italiani, G. CAPELLINI and E. Soitms-LAuBACH: Ueber 
den gegenwirtigen Standpunkt unserer Kenntniss von dem Vorkommen fossiler 
Glacialpflanzen, A. G. NATHORST, 336. 


Miscellaneous Scientific Intelligence—American Association for the Advancement of 
Science, 337.—British Association: Periodic variations in Glaciers: Florida, 
South Carolina and Canadian Phosphates, C. C. H. MILLAR, 342, 


CONTENTS. vil 


Number 2638. 
Page. 


Art. XLIV.—Unity of the Glacial Epoch ; by G. F. Wricur 351 
XLV.—A Photographic Method of Mapping the Magnetic 

PE eldts by Case eh eWiNG =. se wees ee eevee oer sue eye 374 
XLVI.—Contributions to Mineralogy, No. 54; by F. A. 

Grentu. With Crystallographic Notes; by 5. L. PEn- 

UIE IGT peg ay Whee ee seg eon td ls 3) Uy Re Yo 9 beet ea eaters NN aor 381 
XLVII.—The Effects of Self-induction and Distributed 

Static Capacity in a Conductor; by F. BrpEent and A. 

CMC REHOR Bis: sari on yy ea in WO ne ee ee eee 389 
XLVIII.—The Quantitative Determination of Rubidium by 

the Spectroscope; by F. A. Goocu and J. I. PHinney 392 
XLIX.—Notes on the Farmington, Washington County, 


Kansas, Meteorite; by H. L. Preston. .-.._-.-...--- 400 
L.—A Note on the Cretaceous of Northwestern Montana ; 

Vg EVO UINROO Diao 252 es Se S08 ae aN ace al 401 
LI.—The Deep Artesian Boring at Galveston, Texas; by 

esewlicee EL tye eye ec ee Pe Oe eee ee ena AG 


LII.—Notice of a new Lower Oriskany Fauna in Columbia 
County, New York; by C. E. Bexcurr. With an an- 


notated list of fossils; by J. M. Charkm -:.._.. .-.-- 410 
LUI.—Description of the Mt. Joy Meteorite; by E. E. 
JEL iia TTA Dee et aegis eae eal SP aE me ip eee UR 415 


LIV.—Influence of the Concentration of the Ions on the In- 
tensity of Color of Solutions of Salts in Water; by C. 
PAINE RBSRGER 22. oa PURE ERAN Maco Rey Sahota RUT 416 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Relative Densities of Hydrogen and Oxygen, RAYLEIGH, 
418.—Properties of lquid Oxygen and liquid Air, Dewar, 419.—Industrial 
production of Liquid Carbon dioxide, Troost: Oxidation of Nitrogen by the 
Spark, LePet: Inorganic synthesis of Azoimide, W1SLICENUS, 421.—Metallic 
Carbonyls, L. Monn, 422.—Rapid Electrical Oscillations, TonPLER: Electricity 
of Waterfalls, Po. LeENARD: Photography of Color, H. W. VoGEL, 423.—Elec- 
trical Resistance of Allotropic Silver, A. OVERBECK: Relation between Mag- 
netic and Harth Current Phenomena, W. ELLs, 424.—Physics, advanced course, 
G. F: BarRKER, 426. 


Geology and Mineralogy—Geological Survey of Texas, E. T. DouMBLE: Geological 
Survey of Alabama, HK. A. Smrru, 427.—Annual Report of the Arkansas Geo- 
logical Survey for 1892, R. A. F. Penrose: Osteology of Poébrotherium, W. 
B. Scott: Paleeaspis of Claypole, 428.—Devonian fossils from the Islands and 
vicinity of Lakes Manitoba and Winnepegosis, J. F. WuHITEAVES: The Eruptive 
Rocks of Electric Peak and Sepulchre Mt., Yellowstone Nat. Park, J. P. IppDINGs: 
Mittheilungen der Grossh. Badischen Landesanstalt, A. SAUER, 429.—Danalite 
from Cornwall: Mineral Resources of the United States, 430. 


Temperature of the Circumpolar region, 430, 


vill CONTENTS. 


Number 264. 
Page. 


Arr. LV.—Experimental Comparison of Formule for Total 
Radiation between 15° C. and 110° C.; by W. LeContE 


STEVENS 2.22 --0..-4..- cee . 431 
LV1.—Notes on Silver; by M. C. Lma:_-- 2 222332 444 
LVII.—Notes on Silver Chlorides; by M. C. La...._____ 446 


LVIII.—Remarkable Fauna at the Base of the Burlington 
Limestone in Northeastern Missouri; by C. R. Keyus. 447. 


LIX.—Glacial Pot-holes in California; by H. W. Turner 
(With Plate [X)_.2+_. 22s 2e5 2522 


LX.—Lavas of Mount Ingalls, California; by H. W. Turner 455 


LXI.—Method for the Quantitative Separation of Barium 
from Strontium by the action of Amyl Alcohol on the 
Bromides ; by P. E. Brownine)_o2)o) eee eee 459 


LXII.—Note on the method for the Quantitative Separation 
of Strontium from Calcium by the action of Amyl Alco- 
hol on the Nitrates; by P. E. Brownine _----..___-- 462 


LXIII.—Study of the Formation of the Alloys of Tin and 
Tron with descriptions of some new. Alloys; by W. P. 
HEADDEN 2622 5o=" To eck Ee 464 


LXIV.—Notes on the Cambrian Rocks of Pennsylvania and 
Maryland from the Susquehanna to the Potomac; by 
C.. D.: WaLeorn 22.2.2 ges Je Shee a ee 469 


LXV.—Volcanic Rocks of South Mountain in Pennsylvania 
and Maryland; by G. H. Wiriiams. (With Plate X)_ 482 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Temperature of Steam from Boiling Salt-solutions, 
SAKURAI, 496.—Allotropism of Amorphous Carbon, Luzi: Amorphous Boron, 
Morssan, 497.—Atomic Mass of Boron, ABRAHALL: Absorption power of 
metals for the Energy of Electrical waves, BJERKNES: Electrical Oscillations, 
M. ZEHNDER, 498.—Joints in Magnetic Circuits, Ewine: Measurement of high 
temperatures, HOLBORN and WiEN: Color Photography, LIppMANN: Electrical 
Resistance of Metals at Low Temperatures, DEWAR and FLEMING, 499. 


Geology and Natural History—Les Régions Invisibles du Globe et des Espaces 
célestes: Eaux Soaterraines, Tremblements de Terre, Météorites, A. DAUBRER, 
499.—Pleistocene History of Northeastern lowa, W. J. McGrE: Geological 
Survey of Iowa: Tiefencontacte an den intrusiven Diabasen von New Jersey, 
A. ANDREAE and A. OSann: Eleolite-Syenite of Litchfield, Me. and Red Hill, 
N. H., W. 8. Bayzery, 500.—Gems and Precious Stones of North America, G. 
F. Kunz: Muciferous System of Laminariaceze, GUIGNARD: Researches on 
Multiple Buds, W. Russeut, 501.—Artificial intracellular Crystallization, EH. 
BrELzunG: Aeration of Solid Tissues, H. Devaux, 502.—Bibliotheca Zoologica, 
TI, 504. 


Miscellaneous Scientific Intelligence—National Academy of Sciences, 504. 
INDEX to Vol. XLIV, 505. 


ERRAtTUM.—Page 468, line 11 should read: difficultly soluble or insoluble, ete. 


i» aan iv N eh Aas ee , 
Chas. D. Walcott, Ee aits ie 
U.S. Geol. Survey. Vise 4 She Wal ip lat 
CA ; wy, / bX if d/, 


Pe VOL. XIV. JULY, sects 


Established by BENJAMIN SILLIMAN in 1818. 


THE 


AMERICAN 
JOURNAL OF SCIENCE, 


EDITORS 
JAMES D. and EDWARD 6&8. DANA. 


ASSOCIATE #ZDITORS 
Prorrssors JOSIAH P. COOKE, GEORGE L. GOODALE 
- anp JOHN TROWBRIDGE, or CampripcE. 


Proressors H. A. NEWTON anp A. EH. VERRILL, oF 
New Haven, 


ProFrssorn GHORGE F. BARKER, or Puinapeputa. 


THIRD SERIES. 


VOL. XLIV.—[WHOLE NUMBER, CXLIV.] 


set ‘No. 259. —JULY, 1892. 


EW. EUAN TN; CONN.: J. D. & E.S DANA. 
A802, 3 


TUTTLE, MOREHOUSE & TAYLOR, PRINTERS, 371 STATE STREET. 


LT DEEL ET ED EE ES EE ES ETE RL ES 

Published monthly. Six dollars per year (postage prepaid). $6.40 to foreign sub- 
seribers of countries in the Postal Union. Remittances should be made either by 
money orders, registered letters, or bank checks. 


FRENCH AND [ITALIAN MINERALS. 


We have just receiv ed two consignments of nineteen boxes containing minerals _ 


collected and purchased by Prof. Foote, at various localities throughout France 
and Italy. 

Among the more interesting specimens obtained are the following: 

From Allevaud—Beautiful rhombohedral Siderites. After an inspection of all 
the French and Italian museums, Prof. Foote considers the best specimen we have 
to be the finest one in the world. 25c.to $5.00. Largest groups, $5.00 to $15.00. 

From Bourg d’ Oisans. —Axinite, a large lot of groups and single crystals, 
among them some good microscopic specimens, 5c, to $7.50. 

Octahedrite cr rystals on the gangue, 15e. to $2.50. 

Quartz, clear, doubly terminated er ystals occurring singly and in groups. We 
offer these at about the prices the Herkimer quartzes bring. 

Adularia, beautiful microscopic as well as hand specimens. 

Epidote, associated with Axinite, also a few specimens of the now rare 
Chessylite, $2.00 to $7.50. 

Allemontite.—We offer the brightest as specimens at the rate of $1.25 per 
pound. Pure, but rougher, $1.00 per pound. 

Offretite.—A new and beautiful Zeolite, occurring in groups of hexagonal crys- 
tals, 25¢. to $1.50. 

These specimens were selected by Prof. Foote from the private collection of M. 
Gounard, the describer of the species. 

Scheelite, some very large crystals, 25c. to $5.00. 

Dumortierite, from the original locality, 25c. to $2.50. 

From Traversella.—Pyrite. The finest lot of large specimens ever seen. 
Groups of brilliant and perfect crystals, 25c. to $3.50; larger, $5.00 to $15.00. 

An interesting and rare association of Baverno Orthoclase with Fluorite and 
Calcite ; Diadochite ; Christianite; Mesotype; doubly terminated Ortho- 
clase ; Pollux; Rosterite ; Bustamite; Arseniosiderite; Quartz Pseu- 
domorphs: Fahlerz; Chrichtonite ; Prehnite, etc. 


ENGLISH MINERALS. 


As advertised last month we received from Prof. Foote. twenty boxes, the result 
of a month spent in the localities of Derbyshire and Cornwall. 
Full lists of these minerals will be sent on application. 


OTHER RECENT ARRIVALS. 


Boleite.— We have found a great demand for this rare new species but our 
stock still contains a number of brilliant cubes, cubo-octahedrons and a few cleay- 
ages, Perfect crystals, 50c. to $3.50. 

Rubellite.—Of this exceedingly beautiful mineral we haye a large stock, em- 
bracing a variety of forms. Large radiations, clusters of single crystals, many of 
them terminated and separate crystals. Magnificent groups for museums, $2.00 
and upwards. The choicest cabinet specimens from 25¢c. upwards. Fragments. 
Separate crystals, some of which will eut gems of good color, 5c. to 50ce. 

Vesuvianite.—Several large and perfect crystals ranging from two to five 
inches in diameter. 

Crystallized Eudialyte. 

Pseudoleucites, and other interesting Magnet Cove minerals. 

Chrysoberyl.— Another consignment from Greenwood, Me. We are informed 
that these, together with what we have already received, constitute the entire find. 

The finest twins and single crystals in the gangue, $1.50 to $5.00. Character- 
istic, but smaller or imperfect crystals, 5c. to $1.00. 


Japanese Stibnite, Hauerite, crystallized Pyrrhotite ; Crocoite; Poonah 


ppeunyllite, ete., ete. 
We shall be pleased to send selections of minerals on approval to those desiring 
them. 


AA we Con OO Bes Mites 


. MINERALS AND SCIENTIFIC ‘BOOKS, 
4116 Elm Avenue, Philadelphia, Pa., U.S. A. 


A 


AMERICAN JOURNAL OF SCIENCE 


[THIRD SERIES|] 


Oo Pe 


Art. I. — The Change of Heat Conductivity* on Passing 
LIsothermally from Solid to Liquid ; by C. BARus. 


1. Preliminary.—To fully investigate a problem like the 
present, the application of pressures is obviously necessary. 
In my workt on the continuity of solid and liquid I showed, 
however, that hysteresis rarely if ever fails to accompany 
change of state. Since therefore undercooling is not avoided, 
even when pressure changes the state of a body from solid to 
liquid at the same temperature, it seemed permissible to facili- 
tate the experiments by selecting an undercooled liquid at the 
outset. In other words, thymol—and with this substance the 
following measurements were made—which can be kept either 
liquid or solid between 0° and 50° C., merely exhibits under 
atmospheric pressures and temperatures the same volume lag, 
that in more or less pronounced degree is common to most if 
not all crystalline bodies, at pressures and temperatures as a 
rule enormously higher. Apart from this it seems idle to 
ascribe to the molten liquid a more intimate relation to the 
solid than that possessed by the undercooled liquid, without 
distinetly specifying just what the relation is; and this at the 
present state of our knowledge of the solid and liquid mole- 
cule, is impossible. Vague notions about polymerism are little 
to the point. Without evidence to the contrary, I am at 
liberty to suppose that the liquid as well as the solid obey cer- 
tain ideal physical laws; and these I may conceive to be pro- 

* This investigation was suggested by Mr. Clarence King. 
+ This Journal, xlii, p. 125, 1891; cf. p. 140. 


Am. Jour. Scl.—THiIRD SERIES, VOL. XLIV, No. 259.—Juty, 1892. 
1 


2 C. Barus—Change of Heat Conductivity on 


longed indefinitely below the melting point in the former ease, 
and. indefinitely above fusion in the latter case (solid) ; and I 
can estimate the amount of error involved in such a supposi- 
tion by actually comparing any given class of properties of 
the liquid above and below the melting point, by direct ex- 
periment.* 

I may add finally that the application of pressure would 
enormously complicate the method of measurement, which 
even in its simplest form, is not without grave difficulties. 
Indeed the task of keeping thymol liquid between 4° and 15° 
in a copper vessel, proved to be most wearisome, and out of 
very many experiments only relatively few were obtained 
meet thoroughly trustworthy conditions. 

2. Method employed.—Seeing that the available substances 
are usually of low absolute conductivity (below k = 500/10"), 
and keeping in mind the desideratum of a method which could 
eventually be used for bodies under pressure, | found none 
better suited to the present problem than the one which H. F. 
Webert has so brilliantly and elaborately worked out. Weber 
places a thin, wide, plane-parallel plate or layer of the sub- 
stance to be examined between and in close contact with two 
thick plates of copper, and it is proved that these are identical 
as to temperature, with the upper and lower isothermal of the 
layer. §9. The system is first heated so as to be at a given 
temperature throughout. It is then suddenly and permanently 
cooled at the lower surface (copper plate), and the time rate at 
which heat travels from the top plate to the bottom plate, 
through the intervening layer, is measured by a thermo-couple. 
From these data the absolute thermal conductivity of the layer 
may be computed when the constants of the system are known. 
To obviate convection in the ease of liquids, all plane surfaces 
are placed horizontal, and cold surfaces are lowermost. 

To cool the bottom plate Weber either bedded the system 
on a plane of ice, surrounding it by an ice environment, or 
lowered its temperature by a shower bath of hydrant water 
with a corresponding environment. It is not feasible to apply 
this method directly to thymol: clearly, in the first place all 
manner of disturbance or handling must tend to freeze the 
under-cooled liquid. In the second place freshly distilled 
thymol absorbs water or aqueous vapor at an initial rate of 
00032 @ per cm’ of free surface per hour, and the interval of 
undercooling is thereby decreased. At least in contact with 
copper in air, thymol soon becomes colored and unsuitable for 
the experiments. Failing therefore utterly in the attempt to 

*The continuation of the present research must for the above reasons await 


the warm weather. 
+ H. F. Weber: Wied. Ann., x, pp. 103, 304, 472, 1880. 


Passiny Isothermallg from Solid to Liquid. 3 


obtain results for the liquid, $1, I modified the method so as 
to adopt it both for high temperature and low temperature 
environments, as follows. 


Apparatus. 


3. General disposition.—To obtain a circulation of water at 
any constant temperature not more than 80° or 40° above the 
temperature of the hydrant water, I used the device of boiler, 
graduated faucet and distributer, to be described in connection 
with my work on the volume expansion and the thermal 
capacity of thymol.* 


CLT 
ls; 


Fie. 1.—Vertical section of the apparatus for thermal conductivity, with all 
parts in place. Scale 4. 


In figure 1, DD and Hare the cylindrical copper plates 
between which the sample to be tried is sandwiched. The 


* See note in Proceed, Am. Acad., vol. xxvi, p. 313, 1892. 


4 C. Barus—Change of Heat Conductivity on 


system is completely surrounded by a cylindrical box ABC, 
thr ough the hollow walls of which the water continually cireu- | 
lates. In this way an environment of any constant tempera- 
ture is obtained. 

To heat or cool the lower plate #Z) it is made the top of a 
shallow box #7), the bottom of which is perforated by influx 
and efflux tubes @, Gaus 

The whole system, ABO, is heavily jacketed with blanket- 
ing (not shown), and a sink placed below the efflux tubes ear- 
ries off the water. 

4. Environment.—This consists of the three parts AAA, 
BB and CCCC, made of heavy tinned sheet iron, and capable 
of moving up and down and of being clamped in any vertical 
position along four upright slides (not shown). It is advisable 
to fix the bottom CCCC permanently, and the frame is pro- 
vided with leveling screws so that the plates DD and HE may 
be adjusted to the horizontal, accurately. 

The top AAA is virtually a bell jar. Water enters at @ in 
jets directed toward the center as well as toward the right 
(tangentially) so as to keep upa circulation. It issues at 8, 
and passes thence through a sufficient but short length of 
jacketed rubber tubing to the tubulure c, near the bottom of 
the ring BL. Rotation is here also kept up by tangential in- 
flux, and the water issuing at d near the top of BA, passes 
through rubber tubing to ¢ on one side of the bottom ‘CCC, 
finally leaving this vessel at J on the other side. When not 
otherwise used, the water is carried to a level above AAA, to 
prevent siphonage. By making the environment of parts in 
this way, two advantages are secured: for apart from the greater 
thoroughness of circulation favorable to constancy of tempera- 
ture, the parts may be raised so that the plates DD and HE 
may at all times be easily charged or inspected. In the actual 
apparatus the influx and efflux tubulures are to be in a vertical 
plane at right angles to the thermometer tubulures. AAA 
has four other tubulures: 7 (oblique) for the insertion of a 
thermometer into the circulating water, and J/ for registering 
the air temperature within ; through L the air which always 
accumulates from hot water may be discharged, and through 
JV, a wire may be inserted for raising and suspending the 
upper plate DD, $8. Similarly the tubulure & admits a ther- 
mometer into the water circulating in BB. Finally the bot- 
tom CCU has two large and two small perforations, through 
which pass the tubes G, G’, and gg, as well as the wires of the 
thermo-couple, $6. The tubulure 7 reaching nearly to the 
top, discharges accumulated air. 

5. Copper conduction plates.—Both DD and HEF are silver 
plated, making them less subject to the action of thymol. The 


Passing Isothermally from Solid to Liquid. 5 


former (J) is 15:23 in diameter, 1°300° thick, turned accu- 
rately cylindrical and polished on its lower surface. Besides 
the central hole 7, it has two small eyelets, ss, placed symmet- 
rically on the same diameter, by aid of which the plate may 
be suspended, §8. Finally the junction m’ of the thermo-couple 
mm'm is soldered to the top of this plate, the wires passing 
through the tube in the bottom, CC. 

The plate DD is supported on the upper polished plane 
surface of /’Z, by three plate glass spacers ¢, ¢, °1°™ to °2™ high, 
and -2x-2 em’ square. His of the same diameter as DD, 
but only ‘6™ thick. The sides of the box #’/, of which HF is 
the top, project upward to form a gutter ZZ, in which the 
excess of charge is caught and may be siphoned off. In case 
of undercooled liquids this gutter is absolutely essential, and I 
found it advantageous to coat it with vulcanized rubber 
deposited from solution. Rough surfaces induce premature 
freezing. The box /’F’ plants its three steel feet on plates of 
brass (not shown), imbedded in the top of CC, thus securing 
the necessary firmness of the conducting system. Finally the 
junction nv’, of a second thermo-couple nn'n, identical in every 
respect with mm/’m, is soldered to the bottom surface of 2’, 
and after passing through a sealed tubulure V in the side of 
FF, the wires pass out through UC. 

One of the tubes GG which admit and withdraw large 
bulks of water, communicates through a massive three-way 
stop cock /ZX, with the faucet of the hydrant. The tubulure 
gg Which nearly touches the bottom of #, discharges into a 
small cistern with two tubulares 4 and p, and a thermometer, 
qg, here registers the temperature of the efflux through A. 

To introduce the charge, liquid thymol is carefully poured 
in through 7, by aid of a fine funnel tube. In ease of copper 
plates this rarely succeeds at ordinary temperatures. I heated 
the plates during charging above the melting point of thymol, 
and then allowed them to cool in the closed environment. 
The charge is best frozen when quite cold and from the center 
outward, by contact with a crystal, inserted through 7. Allow- 
ance must be made for the volume contraction, $14. In the 
following work with solid thymol, the glass spaces ¢, ¢, were 
left in place. I believe now that this is unfavorable to perfect 
adhesion between the solid layer and the copper plates, even 
though the cold plates were found to be thoroughly cemented 
together. A better plan would be that of placing the spacers 
near the edge, and of removing them as soon as a sufficient 
amount of thymol has solidified to sustain the upper plate. 

6. Lhermo-couple.—The thermo-couples m and n, of german 
silver and copper, being identical both as regards metal and 
dimensions, the temperatures of the upper or the lower plate 


6 CU. Barus—Change of Heat Conductivity on 


could be measured independently ; or by soldering the german 
silver wires together and coupling the ends of the copper wires 
with the galvanometer, differences of temperature could be 
measured. The latter method was adopted since this differen- 
tial quantity enters the formule. Great care must be taken to 
see that the charge is electrically a non-conductor. This is the 
case for thymol, but series of experiments which I made with 
water proved worthless because of this discrepancy. To eali- 
brate the thermo-couples in question, duplicate sets of identical 
wires (metal and dimensions) were at hand. The galvanome- 
ter of my own make showed about 3 scale parts per degree C., 
and it was a periodic and nearly constant in sensitiveness. 

7. Heating and cooling.—There are two methods available 
for heating the system of plates Y and # uniformly through- 
out, to be used respectively, when the environment is of high 
temperature or of low temperature. 

(1.) To heat the plates to the temperature of the (hot) envi- 
ronment, the stop-cock H, is closed relatively to G, and the 
efflux water from 7# led by jacketed rubber tubing, through the 
cork “into G’. The water thus fills #’/' and issues at 4. Its 
temperature is read off at ¢. DD and HE’ soon reach the same ~ 
temperature within -01° C. 

When the actual measurements are to be commenced, water 
from the hydrant is first passed through #7 and A, until its 
temperature is constant. The cock / is now loosened, and at 
a given signal // is suddenly opened into G. The great bulk 
of water now entering /’F} forces out /, and floods the ther- 
mometer reservoir below g. Here therefore temperature is 
again registered by q. 

(2.) In case of the cold (2°-6°) environment, hydrant water 
is passed directly through the tubes @ to 7, but the method of 
heating D, His less simple. If warm water be passed through 
f?, as before, the temperature of / would even after long wait- 
ing exceed that of Y. For plates 1° apart this persistent 
excess amounted to say ‘9° C., varying with the distance between 
the plates, their internal and external conduction, ete. The 
discrepancy may, however, be obviated by using two supplies 
of warm water, one of which is a few degrees (8°-5°) hotter 
than the other. The hotter water* is first passed through & 
and /’F. After the lapse of sufficient time the second hot 
water supply of constant but lower temperature is made to 
replace the other. Thus /’/is slightly cooled at once, whereas 
DP only cools very gradually, but must eventually fall to a 
temperature below /#. Observations are therefore commenced 


* Pletcher’s ‘instantaneous water heater,” furnishes a satisfactory circulation, 
for the temperature of this water need not be very constant. 


Passing Isothermally from Solid to Liquid. i 


{as before) when the thermo-couple shows no difference of the 
temperature between the plates. 

8. Haxternal conductiwity.—To determine the radiation con- 
stant h, I used two methods, in one of which the cold plate 
(D) was raised in an environment hot above and cold below; 
and in the second of which the hot plate (7) was raised in a 
uniformly cold environment. The latter is essentially that of 
Weber. 

The environment being at any constant temperature, [ 
removed the spacers ¢, ¢, and placed the copper plates in con- 
tact. A strong current of water circulating in 7/7, kept the 
plates at the same temperature differing from that of the envi- 
ronment. By aid of threads fastened to ss, and a wire, passing 
through JV, the plate D was now raised and kept suspended by 
a clamp on the outside. During all this time the differential 
thermo-couple was in place and changes of temperature of the 
plate were thus registered. 

Relatively to the slow external conduction, the suspended 
plate DD is always an isothermal region. Hence if J/, be 
the mass, ¢, the specific heat, and w the temperature excess of 
the plate at the time ¢; if /\ (top and sides) be the surface 
toward the hot environment and /’ (bottom) the surface toward 
the cold environment; if finally z be the temperature excess 
of the hot environment and /, the external conductivity, then 
Mc,du =h(f(c-u))dt — h, Fudt, or du/dt +h(F+P)u/Me, 
=h,f't/M.¢,, a differential equation which after integration 
leads to 
Ji Oa 1) 

Fil0aa = Hie) @ 


In 


where /’+ =O, and where wu and w’ correspond respectively 
to ¢and /’. 

In this way I obtained the results of Table 1, where 7’ is the 
initial temperature of the cold plates, and hence t+r’ the 
actual temperature of the environment, and w+r’ the actual 
temperatures of the suspended plate at the consecutive times. 
The table further contains d¢=¢—? and 0 log(#t/O—u)= 
434 In(f\c/O—w')/(Ft/O—x), and finally the values of /,. 


TABLE 1. 
External conductivity. Complex Cold plate raised. 
NO2< Mean environment. Mean. 

dt dlog(fr/O—u) wt’ ie THT’ hy x 10% hi x 107 
SEC “G “GE a, 
180 1811 6°6 57 30°5 1072 1082 
180 1766 76 5°7 30°5 1045 
120 1270 8°5 Oral 30°5 1130 
180 1878 7°3 od 29°9 abi 1040 
180 LE U3 57 29°9 1061 
180 1685 Sail 57 29°9 997 
180 1661 9°5 5:7 29:9 989 


8 C. Barus—Change of [Heat Conductivity on 


In the second method the water circulating in the environ- 
ment came directly from the hydrant, while warm water cir- 
culated through /’/) below the contiguous plates. After the 
lapse of sufficient time the upper plate was raised as before 
and suspended. At the same time the cold water of the envi- 
ronment was passed through /’/; thus making the temperature 
of the walls surrounding the plate / uniform almost instantly. 

The conditions of cooling may be taken from equation (1) 
by making the temperature excess of the environment t=0. 
The equation reduces to In u!/u=h,O¢—V)/M,<¢,. 

Data of this kind are given in Table 2, where d¢=¢—7’ and 
0 log w = 484 In w'/u, and where c is the temperature of the 
environment and w+rt, the actual temperature of the suspended 
plate. It will be seen that groups of consecutive observations 
_ were made after intervals of waiting, and that two independent 
series are in hand. 


: TABLE 2, 
External conductivity. Uniform Hot plate raised. 
environment. Mean. 
ot 6 log wu ULT T Ayx107 hy x107 
NG. OL 26h 
i 180 BH 29°2 5.6 1028 935 
180 1632 29°4 5°6 966 
(ig0 1644 25-7 5:6 973 
Pause 23™ 
180 1555 19°9 5'6 914 
} 180 1559 18°9 5°6 923 
Pause 35™ 
180 1435 13°9 5'6 849 
180 1506 13°4 5'6 891 
180 1653 29°9 5°6 979 919 
180 1671 28°0 5°6 989 
Pause 23™ 
f 180 1590 91°4 5'6 941 
| 180 15638 20°2 56 925 
Pause 217° 
{ 180 1504 16:4 5°6 890 
{180 1546 15°6 56 915 
Pause 32™ 
180 1343 11°5 5°6 795 


Mean : h,== '0000082 + 0000007 w. 


In both series in Table 2, 2, varies with the temperature 
excess; and since these values are better than the data of Table 
1, I have taken the mean equation for /, as appended to Table 
2, for the reduction of the observations below. 


Passing Isothermally from Solid to Liquid. Hy) 


Method of computation. 


9. General case of the environment.—A short resumé of the 
changes of condition involved is here necessary, since for 
reasons specified in §2, I found it necessary to depart somewhat 
from the method of Weber. 

In his masterly discussion of the flow of heat in the plates 
Weber shows that the two copper discs are isothermal regions 
identical to about 1: 1000 with the upper and lower isothermal 
surfaces, respectively, of the enclosed non-metallic liquid, no 
matter what it be. Hence in addition to Fourier’s well known 
equation of heat conduction, the following surface equations 
obtain for the upper plate: Given a set of cylindrical codrdi- 
nates whose origin is in the upper surface of the lower plate, 
and whose axis coincides with the axis of the plates; let dis- 
tance above the surface of reference, radius and azimuth of 
any point, whose temperature excess is « at the time ¢, be rep- 
resented by w, 7 and g, respectively. Let7= # be the radius, 
4, the thickness, /, the exposed surface (top and sides), /’ the 
lower surface of the upper plate, d/, its mass, c, its specific 
heat, and /, its external conductivity. Let J be the thickness 
of the layer of the charge, # its absolute heat conductivity, 
its external conductivity, ¢ its specific heat. Finally let U be 
the uniform temperature excess of the system at the time zero. 
Then the conditions in question are 


1. «=0, u = 0 for all values of ¢. 
2. #£= 4A, uw independent of 7 for all values of ¢. 


du du 
eae ia Me(F) =h F(z),+ h, Fit, 
_r=h, k(du/dr), +hu, =0 


5. t=0, u=U, for all the values of « and *. 


Hm Oo 


Weber expands w in a series of mixed Bessel functions of the 
type 


—kgt/pe . —k( p? + m?)t/pe 
u — Ae Pt/p sin gv+ Be e yt/e 


sin pad (mr) - 

and proves that by suitable spacing the copper discs, the value 
of wis almost wholly contained in the first term even after 
a few seconds. To determine the constant g, the insertion of 
the condition (3) is available: i. e., any of the infinite roots of 
the transcendental resulting, leads to a singular solution of the 
equation of heat conduction, and thus the complete primitive 
is given as the sum of all of these. But inasmuch as the 
squares of the succession of values g, q’,... . increase rapidly, 
the singular solution and the complete primitive again soon 
coincide in the lapse of time. Thus the temperature excess of 


10 C. Barus 


Change of Heat Conductivity on 


the upper plate (and it is here that the thermo-electric measure- 
ment is made) is after a short time (605), 


: ey 2 
v= U sin g4e aes Fecpicmas ((B)) 


where g is the smallest root of the transcendental referred to. 

10. Continwation.—Now the change to be made in these 
deductions in my own case, where the environment may have 
any temperature excess t, given by replacing the condition (8) 
by the equation— 


du du\ 
— A — SS US, == ( a eo 8 ee j 
FA, eS é LF (SZ) tame, 2 (3') 
where p, and p are respectively the densities of the copper plate 
and the charge. Imposing this condition on (6) I obtain 


ae TE, FF, T , ktq?/pe 
ANT Gr sin g4 =kq cosq4+h-Z sin q4—-hz, Te 


or after further reduction 


Ape Ih 


ie = ae Area eM MSE sc 


“Zag, bP Ag 
Hence the value of ¢ in (6) is to be the smallest root of (7). 
If therefore consecutive temperatures, uw, w’,.... are 
measured at consecutive times @, 7’, . . . . equation (6) may be 
solved with reference to i as follows: 


1 : 0 log u 
ee Vi as as A oye ES 


Gg (teak Gs ot Slee 


Equations (7) and (8) show that the arithmetical results can 
only be obtained by successive approximation. Disregarding 
the corrective factor in (7) approximate values of 4 and g are 
first found. These are then put in (7) and (8) and closer values 
of k and g computed. I often repeated this operation again, 
taking full cognizance of the change of g with the mean tem- 
perature of the charge. 

11. Special cases.—(1) If in (7) the temperature excess of 
the environment, 7 = 0, the conditions revert to those of Weber. 

(2). If as in my ease, the initial temperature be the same for 
the plates and the environment, or if initially c = w, the correc- 
tion vanishes at the beginning of the work but increases in the 
lapse of time. 

If «=, throughout, the radiation correction would always 
vanish. Now it struck me that it might be very well worth 


Passing Isothermally from Solid to Liquid. 11 


while to construct an apparatus for 7=~; for although ordi- 
narily the correction for surface conduction is nearly enough 
given by the computed value, there are cases of exceptionally 
bad conduction (for instance in gases) where this is no longer 
fully the case. Suppose, however, the system be duplicated 
as in figure 2. Let the 
lower pair of plates, D, £; 
be like those of the above 
figure. Let the upper 
pair of plates D’, L”, be 
somewhat larger, and the = 
conductor D’, somewhat N 
thinner and shallowly bell- 
shaped, so as to surround 
‘the plate D on all exposed 
sides Then if d4/pc/ 
Wig — Ain cic othe 
constants g and q’ for the 
two systems will be iden- Fig. 2.—Duplicate apparatus for heat 
tical to a second degree of conduction: 
approximation. Hence U= UA» and therefore as regards the 


RSS MNNWIRAAAS SSK 


£6 5111 


plate D, ct = wu at all times. 

In using this device for measuring conduction in gases, the 
environment A £ C, figure 1, would have to be sealed hermeti- 
cally, and the gas to be studied, introduced into the whole 
interior space, at any temperature (environment) or pressure 
desirable. In such a case, since d= 4’, p= p', c=’, ¢,= 6, 
the simple conditions are 

HfF'= M,/M 

(4) If the environment be at a temperature intermediate 
between the initial and the final values w of a given pair of 
observations, then 1—zc/w passes from positive to negative 
values, and the corrective may also vanish; but this case is 
superfluous here. 

Returning for a moment to case (2), it is clear that the radia- 
tion corrective is least when the temperature gradient of the 
layer is steepest. So long therefore as the thermal variation 


of conductivity is not fully known, it is advisable to prefer 
small values both of UY and 4. 


Experimental Results. 


12. Method of observation.—If after the lapse of 60 minutes 
the plates were heated uniformly, the cold water faucet was 
suddenly opened; but observations of temperature (w) and 
time (¢) were not commenced until a minute later. A good 


12 C. Barus—Change of Heat Conductivity on 


chronometer beating half seconds was at hand for time measure- 
ment, and temperatures (since relative values enter the formulz) 
were directly given by the deflections of the dead beat galva- 
nometer, reduced to ares. For charges 1°™ thick (4), observa- 
tions were taken every 20°, for charges 15°" thick every 30°°, 
and for charges :19° thick every 60*°*. Usually 24 readings 
were made for each heating, which were then combined in 
four batches of 6 observations each, By joining the 1st and 
4th, 2d and 5th, ete., I therefore obtained 12 data for k, with 
the mean temperature corresponding to each. 

Readings of the zero of the galvanometer, and of the tem- 
perature of the environment were taken before and after the 
time measurements; temperatures of the hot bath at the begin- 
ning, temperatures of the cold bath at the end of the work. 

13. Hxhibit.—To avoid prolixity I will only give an example 
of the way in which the work was done. In addition to the 
corresponding increments of time (0¢) and logarithmic tempera- 
ture (0 log w), table 3 contains the (actual) temperatures, w, to 
u,, of the upper plate at the beginning and end of each batch 
of six consecutive readings. Thus each value of / is a mean 
of three pairs of sufficient data. Furthermore c is (henceforth*) 
the actual temperature of the environment, U the initial tem- 
perature of the upper and lower plate, @ the temperature of 
the cold bath; and @ finally is the mean temperature of the 
charge, the bottom being constantly cold (#°) and the top hot 
(w°). The table also contains the mean value of the corrective 


= (1 —Apeh, F(1 = =) [Ape ck Fg’) 


of equation (7) $10. 

The two cases in which the environment has the final (cold) 
or the initial (hot) temperature of the plates are distinguished 
as method I and II, respectively. In case of solid thymol both 
were tested and led to identical results. $17. 

To obviate discrepancies due to imperfect adhesion, expan- 
sion, ete., of solid thymol, three different values of J are intro- 
duced as a check on the method. 

14. Constants.—Supplementing §§ 8-10, I need only add that 
an allowance (7) of 5 per cent of “i was made for the contrae- 
tion of thymol on solidifying. 


Ti e23rcmig Ap—alcoO Ome 
PS 2a bs coe 
F-f=1734 « c= 933 g. cal. 


* To avoid cumbersome notation. 


Passing Isothermally from Solid to Liquid. 13 


15. Specific heat and density.—In a series of experiments 
described elsewhere* and considerably extended since, I found 
for solid thymol (if ¢ and g denote specific heat, density, and 
temperature, respectively.) 

¢ = 311 (1+°003026), 
1/p = -9631/(1— (0002456 +26)8) 


and for liquid thymol 


¢='447 (1+ -002380) 
1/o = 1:00113/(1—(-0007600 + 20))6 


Hence with sufficient accuracy for the present data the tem- 
perature factor of co for the solid was put (L+:00280), and for 
the liquid (1+:0016@). In computing the correction factor in 
equation (7), $10, 2, was therefore referred to surface tempera- 
tures of the upper plate, while the other quantities p, «, g, 
obtain for the mean temperature @ of the charge. 


TABLE 3. Heat condition of solid thymol. A=-1070™; JZ, Low temperature 
environment. 


Uy tO Us ot 104x dlog uw Mean @ Ge T mx10?kx 108 
aCe BC: °C. ECE ar eG? g/cs 
24°8-19°7 5,™08—6™05 805 14°1 27°8 | 5:9 6°2 961 356 
28°7 | 
5,20—6,20 822 
5,40—6,40 822 
18°8-15°4 7,0 -8, 0 825 6 ee One Or 2 965s 06 
7,20—8,20 821 
7,40—8,40 820 
14°8-12°4 9, 0—-10,0 817 9°8 — 59 62 965 354 


9,20-10,20 8il 
9,40-10,40 815 
EO NO te wei 12) ON S10) 8-610 = 4 5-0) 469 B66.) 855 
11,20-12,20 812 
11,40-12,40 827 


AAO Oem IT, High temperature environment.t 
Zoe ale 3 Or 42 Oe CO 13°6 27°38) 5°9 285 1019 360 
3,20—4,20 785 27°8 
3,40—4,40 790 
RGro— Nowe wo. c0—Ge 0 172 11°8 — 59 285 1043 360 


5,20—6,20 768 
5,40-6,40 r3 
14°6-12°4 7, 0-8, 0 TAT ai — 59 28:5 1075 361 
7,20—8,20 755 
7,40-8,40 743 
LEV NO Be Gandy. 723 8°6 — 59 28°5 1120 360 
9,20—10,20 ile 
9,40—10,40 709 
* Proceed. Am. Acad., xxvi, p. 313,1892. + Plate H suddenly cooled at 4™ 0s. 
} Plate # suddenly cooled at 2™ 05. 


14 C. Barus—Change of Heat Conductivity, ete. 


17. Digest.—My data for & have been summarized in Table 
4. In constructing mean values for £, for each heating, data 
below 10°= @ are usually discarded, because in these cases the 
correction factor m can no longer be found without difficulty 
in view of the rapid variation of g. The table also contains 
the mean values for thermometric conductivity (x =/pe) 
obtained ($15) by putting for the liquid at 13°, oc ="453, and 
for the solid at 12° and at 11°, oc ="384 and -333 respectively, 
with the corresponding mean # for each spacing, 4. 


TABLE 4.—Conductivity of solid and of liquid thymol. Summary. 


Solid Thymol, A = -192°™ | Mean k x 108 
Mean kx 108 | © &x108 &x10& =&x108 Method 
@ k&x10® &x10® «x10® Method|/°C, g/es g/es 
°C = g/es_—s ges 928° Ne SBA Toke a ae 
144 356) 356 358 1) |) 8x30 Bas C784 Ser 
105 3579 1072 113-6 353 353 aes I 
84 345 | 11-2 eh UA ot 
7-4. 318 | 95 346 Bie ie Pe 
144 36] SGLawe ee DE ol Bea SEG) Pie 
11°5 See Bede cue heen 13:6 360 360.5 eee II 
9-7 356 ede og Ake /11:8 360 SPS OS ae 
85-35] A a eecie k [97 361 Deeps te 
"4 335 ces a ese | 8:6 360 Spit Faq 
Solid Thymol, A = -153°™ ae ee SOL) 9 2222 pe 
1 B06) 371 366 Tt *|o-ge eran seein ene 
Le? 374 ee ha 1096 14-2 250 354 es II 
95 370 ---- === |11°6 356 be Sten add 
SO) (etOoe Sasa Sood Q:Bkteu S05 ike ey ae 
113-5 373 371 ida If | 13:3 244 347 Sa Ir 
TP BH asee ---- 11:3. 350 AUP AER 
95 369 ---- ---- 97 347 ia as oe 
84 369 ----  ---- NS Sie oek S460) tees 
14°8 371 Suis Sos 100 11:2 348 ate ee 
PIL 377 » ey aes ye 9:7 349 nae ar 
OS ai ee Dae al | 
9-2 375 aos ---- | Liquid Thymol, A = :107™ 
159 364 Sux ea We | 
12° 381 meee Be, Nes 17°5 = 305 307 313 II 
10° 375 ete Oe 143 306 ee 691 
9-5 367 Rae fn 12°0 311 Soe ae 
1G, BBOR | BAS ISI de gr has. Seite 313° --=- | TE 
1570 vy) SCONES, a tude re ae ste) Se 
- « e ‘oO < aS SeSS 
TOMER, oar ae 149 311 4 Sg d) 2 ae 
Nea 348) eo II ae ae ess eee 
9. 4 \ Ey bei ‘Oo Saas Soon 
Le eee (0 alee se ae EN) Be lel 
9°3 344 awe oy ee: IDET 329 Pps Ces 
-110°8 328 eT A one 
Solid Thymol, A= -‘107™ G-4eeas 02 310 Stew i 
14:1 366 365 354 Ie EHR VSS Peak Wa et: 
115 366 ce OGS day 315 deter oh Aorta ths 
9:8 365 ie. feist 13-9 304 Sse a II 
86 364 De eh, Haig. BILL Hes enya 
14:1 356 355 ieee ee I 10:2 309 Send” yes 
116 356 BA | ici. | 


_ Penfield and Pearce—Polybasite and Tennantite, etc. 15 


18. Conclusion.—The results of this long and tedious inves- 
tigation may be stated in afew words. The mean values of 
the absolute heat conductivity, &, of thymol, obtained from 
the measurements as a whole are in g/cs. 


Solid thymol, 12° 10°xk = 359 
Liquid thymol, 13°, 10°xk'’= 313 


The mean values of thermometric heat conductivity z, are in ¢’/s, 


Solid thymol, 12°, 10°X x= 1077 
Liquid thymol, 13°, 10°X x= 691 


Hence the increment of heat conductivity, encountered on 
passing from liquid to solid, at say 13°, referred to solid con- 
ductivity, 


(A—k’)/k = "13, (x—1')/u = 36; 


and the corresponding increment referred to liquid conduc- 
tivity is 
(% — k')/k'="15, (1 — x')/x! = "56 


Now since in all questions relative to thermal flux, it is the 
thermometric conductivity which enters fundamentally into 
the considerations, the importance of the effect produced when 
any part of the substance changes state is obvious. 


Art. IL—On Polybasite and Tennantite from the Mollie 
Gibson Mine in Aspen, Colorado; by S. L. PENFIELD and 
STANLEY H. PEARCE. 


Durine the past year the Mollie Gibson Mine has been 
one of the most productive in Colorado. Our attention was 
first called to the specimens from there by Dr. Richard Pearce 
of Denver, who sent a few to New Haven for identification. 
Later Mr. C. E. Palmer, general Manager of the Mollie Gibson 
Consolidated Mining and Milling Company, generally supplied 
us with specimens and information concerning their occurrence. 
We take pleasure in expressing to both of these gentlemen our 
thanks for their courtesy. From Mr. Palmer’s annual report 
to the stockholders for the year 1891, of his company we quote 
some figures, which are of interest as showing the wonderful 
richness of the mine. Most of the production dates from the 
month of March, when the rich ore was first encountered, and 


16 Penfield and Pearce—Polybasite and Tennantite 


for the most part was taken from an area of about one half 
acre of territory, with a maximum depth of but 300 feet. Net 
weight of ore 9,080,570 Ibs., carrying 2,053,149 ounces of 
silver , an average of 452°2 ounces per ton. 

The rich ore occurs between a hanging wall of black car- 
bonaceous shale and a foot wall of gray magnesian limestone, 
which is probably of lower carboniferous age. The ore is 
richest and most abundant immediately under the black shales. 
The minerals which have been observed at the mine are poly- 
basite, tennantite, native silver (sometimes in very beautiful 
specimens), argentite, galena, sphalerite, siderite, barite and 
calcite. 


Polybasite or “ brittle silver” of the miners. 


This is the most abundant silver mineral at the mine and 
occurs massive, with grayish black color and irregular fracture. 
Large quantities of it, nearly free from gangue, have been 
mined, assaying from 10,000 to 16,000 ounces of silver to the 
ton. A very abundant ‘and conspicuous ore is a pink barite 
(“* pink spar”) with the polybasite disseminated, quite uni- 
formly through it and assaying from 1800 to 2700 ounces of 
silver to the ton. The mineral also occurs as streaks and par- 
ticles in the shales and limestones on the borders of the deposit, 
and even some seams of impure coal, above the shales, are quite 
rich in silver. 

The massive polybasite is not a pure mineral as it appears at 
first sight to be. The analyses show a wide variation in the 
per centage of lead and do not yield a satisfactory formula until 
this metal is deducted in the form of galena, although the lat- 
ter isno where visible in the material which was analyzed. 
The remaining impurity consists of a carbonate of iron and 
manganese, which is very evenly distributed, is black from car- 
bonaceous material and not conspicuous in the metallic sulphide. 
The analysis is given beyond. 

Some of the specimens consist of a fine grained, crystalline 
carbonate of iron, manganese and zine, having a brown color 
and probably a variety of siderite. This seems to have been 
deposited over tabular crystals of polybasite, but it can not be 
broken away so as to show the crystalline form of the latter as 
it adheres quite tenaciously. Some of the polybasite crystals 
are surrounded first by a layer of siderite, then by a narrow 
zone of metallic mineral and then again by siderite. As this 
seemed to be the nearest approach to the pure crystallized silver 
mineral, which we were likely to obtain, great pains was taken 
to pick out a sufficient quantity for the following analysis. 


from Mollie Gibson Mine, Aspen, Colorado. IU 


Massive mineral. 
Analysis by S. H. Pearce. 


Specific SEAVIEY of three pieces Crystals from siderite. 
6-06, 5°92 and 6 Analysis by S. L. Penfield. 
I, “Tr. Average. Specific gravity 6080. 

NS) NOT LOrS Se. Oso S 17°42 
As 448 446 447 AS 6°10 
Sb OSS Feu 0°13 Sb 0°26 
Ag 42°52 42°45 42°49 Ag 49°51 
Cu 9:21 9°15 9:18 Cu 1292 
Zn 2°23 2°20 et) Zn 245 
Pb 20°84 20°32 2083 =galena, PbS 24°05 Pb IMD) 2S IZ OS WHY 
ECO Gar ORC PASO) FeCO; 0:46) 6-59 
MnCO; 0°98 1:07 1:03 \ 4-13 MnCO3 0°13 { 
CaCOre 0-20 net) 0-20 
Insol. 0°32 342) 50°33) 


997311 Impurity 28:18 99°83 Impurity 12°8h 


The above analyses do not agree, nor in their present form 
can they be referred to any known species, but after deducting 
28:18 per cent of impurities from the first and 12°81 from the 
second, and recalculating to one hundred the results are as 
follows: 


Massive mineral. Crystals from siderite Theoretical composition where 
Sp. gr. corrected = 594 Age: Cus: Zn=263: 117: 43 
) 17°73 18°13 Ratio 18°13 
As 6°29 701+150 ='0467 0479 7°08 
Shy 0218 023024420012 

ee O97 56°90+216 = °263 57°0% 
Cita 12-91 14°85 +126°8= °117 } °423 14°91 
Zu 3°16 2°81+- 65 = :043 Bs) 
100°00 100°00 100°00 


The analyses are now similar and in the second, which was 
made on the purest material, the ratio of (Ag,+Ou,+Zn): 
(As, +Sb,)=°423 : 0479 or 9:00:1:02, almost exactly that re- 
quired by the formula 9Ag,S, As,S,. As is always the case 
with this mineral, a rather large proportion of the Ag, has been 
replaced by Cu, and some by Zn. The analyses are also 
interesting as showing that this mineral is a nearly pure arsen- 
ical polybasite. H. Rose* gives one analysis of a variety 
from Chemnitz in Saxony, which agrees with ours in contain- 
ing only a trace of antimony ; with this exception, in all of the 
analyses which have been published, antimony predominates. 
Although polybasite has been known to occur in the United 
States, ‘the only published analysis is one by F. A. Genth+ of 
a crystal from the Terrible Lode, in Clear Creek Co., Colorado. 

* Poge. Annalen, xxviii, 1833, p. 156. 
+ Proce. Amer Phil. Society, xxili, 1886, p. 39. 


AM. JouR. SCI.—THIRD SERIES, Von. XLIV, No. 259.—JtLy, 1892. 
5 


a 


18 Penfield and Pearce—Polybasite and Tennantite, ete. 


Tennantite or arsenical tetrahedrite. “ Gray copper” in part of 
the miners. 


Among the specimens of massive polybasite, just described, 
there were a few which contained patches of a steel gray min- 
eral, differing only slightly in color from the blacker polybasite. 
No ‘crystals were observed and it was necessary to pick very 
carefully, in order to secure sufficient pure material for the 
following analysis. “The mineral gave a reddish streak, only a 
little darker in color than that of hematite. The analysis by 
Penfield is as follows : 


Theoretical composition 


Specific gravity, 4°56 where Cuz: Ago: Zn=282: 63: 106 
Ss 25°04 25°66 
As 17°18+150 =:11465 17°18 
Sb O°15+244 ='0005 Lis 
Cu 85°72--126°S= ‘282 |. 36°29 
Ag 13°65+216 = :063 | 13°86 
Zn 690+ 65 = '106°}:463 7°01 
Fe 0'42= 56 = -008 | 
Pb 0°86+207 = -004 | 
99:90 100°00 


The ratio of the metals to (As,+Sb,)=°463:-115 or 4:00: 
0-99, almost exactly that required by the formula 40Cu,S, 
As,§,. A part of the Cu, is replaced by Ag, and Zn. It is 
not certain whether the small quantities of Fe and Pb are 
impurities or whether they belong to the mineral. The 
analysis is interesting as it shows an unusually high percentage 
of silver. 

Although tennantite has been ee 8 to occur in the United 
States, we can find no analyses, and very little mention of it 
in scientific literature. 

According to information received from Dr. Pearce, and 
from our own experience, polybasite and tennantite are not 
rare silver ores in Colorado. Polybasite occurs well erystal- 
lized in the mines about Georgetown, at the Yankee Boy mine 
near Ouray, in the Marshall Basin near Telluride and probably 
at a number of mines in the Red Mountain District. Tennan- 
tite has been observed well crystallized at the mines about 
Central City and at the Freeland Lode and Crocett Mine near 
Idaho Springs. 

Mineralogical Laboratory of the Sheffield Scientific School, 

New Haven, Dec., 1891. 


W. Cross—Post-Laramie Deposits of Colorado. 19 


Art. I1.—Post-Laramie Deposits of Colorado; by Wutt- 
MAN Cross. 


[Published by the permission of the Director of the U. S. Geological Survey. | 


Introductory. 


AMONG questions in American geology which have given 
rise to prolonged discussion and controversy, few if any have 
been more prominent than that as to the age of the great 
Laramie Formation or Group of the Rocky Mountain resion, 
This observation, made by Mr. Clarence King in the final 
report of the Fortieth Parallel survey, in 1878, is still more 
true to-day than it was at that time. When it is considered, 
however, that a very large part of the earlier publications were 
based upon mere geological reconnaissance, and that the area 
involved extends across the United States in its most inacces- 
sible and least known portion, from Mexico to British 
America, it must be plain that controversies and misunder- 
standings were unavoidable, and indeed quite natural. 

A few years ago it seemed to many geologists that the Lar- 
amie question was practically settled, or in a fair way to 
settlement. But, as certain areas of the West have been more 
carefully explored, the question has been in a measure re- 
opened, but with a change in its phase, so that it is not now so 
much “To what age does the Laramie belong?” as it is 
* What belongs to the Laramie?” or the newer researches, 
whatever their direction, all tend to show that the Laramie 
has been a great omnibus division into which has been cast 
everything ascertained to lie between the marine Cretaceous 
and the lowest recognized Eocene deposits, together with a 
number of other formations whose positions were not deter- 
mined. It is the aim of this paper to show that there exists at 
pee one important group of formations which have been 

onsidered as belonging to the Laramie, but which are very 
markedly distinct from the formation to which that name 
properly belongs. 

As far as the writer is aware the first definite proof that a 
given section assigned to the typical Laramie contained mem- 
bers separated by important unconformities and of widely 
different lithological character, was afforded by the work done 
in the vicinity of Denver, by the Colorado Division of the U. 
S. Geological Survey, in charge of Mr. S. F. Emmons. A 
preliminar y account of these researches was presented to the 
Colorado Scientific Society, July 2, 1888, in articles by G. H. 


20 W. Cross—Post-Laramie Deposits of Colorado. 


Eldridge and the writer.* In this Journal for April, 1889, 
the second of these articles “The Denver Tertiary Forma- 
tion,’ was published in revised form. During the last three 
years further discoveries bearing upon this question have been 
made in various fields by several observers, and it is desired to 
present here a connected statement of these new facts, together 
with a discussion of their significance. 


Description of the Deposits. 


Denver and Arapahoe Formations.—In the detailed exam- 
ination of the Denver region above mentioned, it was found 
that the continuous so-called “ Laramie” section exposed near 
Golden consisted of three divisions: 1°, a lower member, 700 
—800 feet thick, conformable with the Fox Hills, containing 
- productive coal measures and a flora and fauna characteristic 
of the Laramie as commonly known; 2°, a middle member, 
800 feet thick, unconformable with the lower member, char- 
acterized by a conglomerate which carries pebbles recognized 
as coming from the Laramie, Fox Hills, Niobrara, Benton, and 
Dakota, Cretaceous, the Jura, the Trias, and the Carbonifer- 
ous; 3°, an upper member, 1400 feet thick, unconformable 
with the middle member, and characterized lithologically as 
composed very largely of debris of andesitic lavas, none of 
which appeared in the preceding deposits. To the middle 
member of this series Mr. Eldridge gave the name “The 
Arapahoe Beds; ” to the upper member was assigned the name 
“The Denver Beds.” It was found that the celebiated 
fossil-leaf horizon of Table Mountain, at Golden, belonged to 
the Denver beds and consequently that the “ Laramie” flora 
of Golden, described by Lesquereux and Ward, belonged to 
two distinguishable horizons, and chiefly to the upper one. 
The Arapahoe and Denver beds were found to contain a ver- 
tebrate fauna not known in the coal measures below, and to 
this point reference will be made in a later section of this 
article. 

The stratigraphical and lithological evidence above summa- 
rized indicated clearly that the Arapahoe and Denver beds 
were separated from the Laramie below by a long period of 
very important orographic disturbances, as attested by the 
pebbles in the Arapahoe conglomerate. As the fossil flora and 
fauna of the formations did not seem to be necessarily opposed, 
the two formations in question were referred in.the publica- 
tions cited to the early Eocene, and probably to a horizon 

* On some stratigraphical and structural features of the country about Denver, 


Colorado; by George H. Eldridge. The Denver Tertiary Formation; by Whit- 
man Cross. Proce. Col. Sci. Soc., vol. iii, part I, pp. 86-133. 


W. Cross—Post-Laramie Deposits of Colorado. 21 


below any other recognized member of that division. Having 
thus briefly restated the stratigraphical evidence of the forma- 
tions near Denver the developments of the last three years in 
other districts will be reviewed. 

fluerfano Series.—In the Huerfano basin in southern Col- 
orado Mr. R. C. Hills has discovered and described * a series 
of strata 7,100 feet in thickness which he refers to the Eocene, 
because their lower member is decidedly unconformable with 
the underlying well-known coal-bearing Laramie of southern 
Colorado, and because the upper division contains mammalian 
remains of the Bridger Eocene. For the whole series Mr. 
Hills submits the following scheme of division : 


Huerfano beds, 3,300 feet=Bridger Group. 
Huerfano Series { Cuchara beds, 300 feet 
(Eocene) Poison Cafion beds, 3,500 feet 


Great angular unconformity exists between the Laramie and 
the Poison Cafion beds, but none has been detected between 
the designated members of the new series. The Poison Cafion 
and Cuchara beds are at present separated from each other and 
from the Huerfano beds on lithological grounds only, the 
former consisting of “soft sandstones and fine conglomerates 
of a yellowish tint, with occasional bands of yellow clay or 
marl,” while the latter is a well defined horizon of “ pink and 
white massive sandstones.” The Huerfano beds consist of 
‘““marls, clays, soft shales and sands, of red, gray, yellow, green 
and purple colors, red predominating.” In these have been 
found remains of TZtllothervwm, Hyrachyus, Glyptosaurus, 
Paleosyops, and other forms which seem to correlate the 
strata containing them with the Bridger Eocene. This dis- 
covery of Eocene deposits, containing a well-marked mam- 
malian fauna, on the eastern slope of the Rocky Mountains is 
certainly significant. And it is highly probable, as pointed 
out by Mr. Hills, that the Cuchara and Poison Cafion beds are 
contemporary with some of the other post-Laramie formations 
to be mentioned. 

Gunnison County.—A fund of new observations bearing 
upon the present question is to be found in the address of Mr. 
hh. C. Hills as retiring President of the Colorado Scientific 
Society, delivered December 15, 1890, but only very recently 
published.t In that portion of this address treating of the 


| Lower Eocene. 


* The recently discovered Tertiary beds of the Huerfano river basin, Colorado 
(with map); Proc. Col. Scientific Society, vol. iii, part I, pp. 148-164, 1888. 

Additional notes on the Huerfano beds; ibid, vol. ili, part Il. pp. 217-223, 1889. 

Remarks on the classification of the Huerfano Eoceue. Read before the Col. 
Sci. Soc, Feb. 2, 1891. Not yet published in full. 

+ Orographic and structural features of Rocky Mountain geology, Proc. Col. 
Sci. Soc, vol. iii, part III, pp. 359-458. 1891. 


22 W. Cross—Post-Laramie Deposits of Colorado. 


period between the marine Cretaceous and the Wasatch 
Eocene, Mr. Hills gives much important original information 
concerning the Laramie and various post-Laramie formations. 

The first one of these later deposits to be mentioned occurs 
in western Colorado on the western slope of the Elk Moun- 
tains. Its southern limit, as now known, is about Irwin, a few 
miles to the westward of Crested Butte in Gunnison County. 
It rests upon the normal Laramie carrying anthracite coal beds 
on the northern slopes of the Anthracite range, occupies a 
considerable area at the head of Anthracite creek, and thence 
extends northward for 80 miles to Grand river. The develop- 
ment on Anthracite creek comes within a district which has 
been examined in detail by the Colorado division of the U.S. 
Geological Survey. In the course of this work the provisional 
name of the “Ruby beds” was assigned to these strata on 
account of their prominent development in Ruby Peak, near 
Irwin, where their thickness exceeds 2,000 feet, and this name 
is used by Mr. Hills in his address in refer ring to them. 

In the Irwin region the Laramie strata have a thickness of 
about 1500 feet. They are succeeded by 2000 feet of con- 
elomerates, sands and shales, composed almost entirely of the 
debris of volcanic rocks of andesitic character, here much 
hardened and metamorphosed by later eruptive rocks which 
pierce them in numerous dikes. The basal member of the 
series is a conglomerate of small pebbles, which is usually 
uncomformable on a small scale with the Laramie, and also 
exhibits a great variability in constitution. In some places it 
consists entirely of andesitic pebbles, in others, of a mixture of’ 
such material with white, black or reddish chert pebbles, some 
of which show cavities representing crinoid stems. Again, 
the lower part of the conglomerate may be free from andesitic 
pebbles. 

To the northward of the Irwin region Mr Hills has traced 
out the Ruby beds, with a decreasing thickness reaching a 
minimum of 300 feet near the northern limit on Grand river. 
Concerning their development at this point Mr. Hills says: 
‘“‘ South of the Great Hogback at. Coal'ridge, there is an abrupt 
change in the composition of the sediments previously re- 
garded as Laramie. The firm gray sandstones of the coal 
measures are there succeeded by about 200 feet of soft white 
sandstones and yellow clays, followed by about 800 feet of 
tufaceous strata, more or less conglomeritic and usually loosely 
aggregated, but resting on a hard, coarse basal conglomerate 
about 40 feet thick made up wholly of eruptive debris. The 
tufaceous beds are in turn succeeded by 600 feet or more of 
shales and soft brownish sandstones which may be in part of 
Wasatch age.” * 

OpucitewpooO 


W. Cross—Post-Laramie Deposits of Colorado. 23 


On Ohio creek, but a few miles beyond the southern limit 
of the Ruby beds, there are two small isolated patches of loose 
friable sandstones, grits, and fine conglomerates, resting on the 
coal-measures of the Laramie, and seemingly in small basins of 
erosion. Owing to the disturbances caused by adjacent lacco- 
lites it is impossible to see the relationship of the formations 
clearly. The chert pebbles of these beds contain crinoid stems 
and other apparently Carboniferous fossils, and are identical 
in character with those already mentioned as frequently found 
in the basal conglomerate of the Ruby beds near Irwin. These 
tacts suggest that the chert pebbles of the Ruby conglomerate 
may be the residuum from the destruction of Ohio creek beds 
formerly existing to the north of the Anthracite range. Mr. 
Hills does not mention such pebbles in the section near Coal 
ridge above described, but he does suggest a possible correla- 
tion between the Ohio creek beds and the soft yellowish sand- 
stones found at the north between the “firm gray sandstones 
of the coal-meagures” and the Ruby conglomerate. He also 
thinks that the Carboniferous chert pebbles of the Ohio creek 
beds indicate a post-Laramie erosion of the entire Cretaceous 
section, exposing Carboniferous strata. Whether this hypoth- 
esis be established or not it is true that such materials are not 
seen in the Cretaceous beds above the Dakota conglomerate, 
and it is not known to the writer that they have been found 
at that horizon in this region, though not uncommon along 
the Front range and in Middle Park. 

Mr. Hills has found that on Grand river the Ruby beds lie 
between the Wasatch and the Laramie. The lithological and 
stratigraphical evidence given there distinctly suggests that 
the Ruby beds may be the equivalent of the Denver forma- 
tion, and less decidedly that the Ohio creek beds may possibly 
represent the Arapahoe formation. No fossils excepting car- 
bonized plant stems have been found in the two new forma- 
tions. The writer does not place much weight on the mere 
coincidence in eruptive character of the materials in the Ruby 
and Denver beds, beyond the marked fact which seems to be 
developing from experience that a number of formations of 
apparently the same stratigraphical position are thus charac- 
terized. It may finally come to be a criterion of considerable 
value. 

Yampa fiver.—In northwestern Colorado on the Yampa 
river Mr. Hills finds reason to believe that there is a distinct 
formation between the Laramie proper and the Wasatch, but 
is at present able to give no positive evidence for this view 
except that the normal series of the Laramie has above it a 
formation “of soft sandy strata with some shales and clays” 
containing impure lignitic beds, and of general different 


24 W. Cross 


Post-Laramie Deposits of Colorado. 


physical appearance from the beds of the Laramie. Above 
these are unquestioned Wasatch beds.* 

South Park.—Near Como in South Park, Colorado, Mr. 
Hills has found a very remarkable formation which will be 
best described in his own language: ‘‘ While recently en- 
gaged in the examination of the small Laramie area in the 
South Park basin, I there observed unquestionable evidence 
of a former grand eruption, of a character not previously noted 
in that part ‘of Colorado. The evidence consists in the occur- 
rence of thick sheets of eruptive conglomerate, intruded 
partly into the marine Cretaceous and partly into the Laramie, 
to some extent above the workable coal. These sheets are 
continuous from Mine No. 5 near Como to the southern limit 
of the Laramie beds, a distance of fully fifteen miles, beyond 
which I did not trace the exposures. About three miles south 
of Mine No. 5, the intrusions above and below the coal beds 
coalesce and form a body of conglomerate several hundred 
feet thick completely cutting out the workable measures for 
nearly a mile. The material consists of rounded pebbles and 
bowlders of andesite embedded in a matrix of finer material 
of similar composition.” .. . ‘The material itself may be re- 
garded as the product of intense dynamic movement, probably 
brought to the surface as a hot conglomeritic mud, or in a 
condition to produce an explosive eruption, whenever, owing 
to diminished pressure, the contained water flashed into 
steam.” .. . “ The material then thrown out and scattered over 
the surface would be in a condition to be transported in large 
quantities to the nearest area of sedimentation—the Denver 
basin—and presumably at the very time when the Denver beds 
were laid down.” + 

It seems to the writer that the character ascribed to the 
South Park eruption is so novel and its extent so far a matter 
of speculation that it can at present hardly enter as an 
important factor into the question as to the origin of the 
eruptive materials of the Denver beds. The facts concerning 
the constitution of the Denver beds given in the original 
article do not allow of the adoption of Mr. Hills’ suggestion. 
They demand a source near at hand and one whose location 
shall explain why eruptive material practically excludes 
Archeean material in fine, slowly deposited sediments, close to 
an Archeean shore-line. : 

Caron City.—In his address Mr. Hills refers to remnants 
of a formation near Cation City which seems related to the 
Denver formation. Through his kindness in personally com- 
municating the news of his “discover y, my colleague, Mr. G. H. 
Eldridge, was enabled in the season of 1890 to hurriedly 


* Op. cit., p. 389. t Op. cit., pp. 393, 394. 


W. Cross—Post-Laramie Deposits of Colorado. 25 


examine the region, in connection with other field work, and 
kindly allows me to state the results. At Windy Gap, a few 
miles east of south from Cafion City, Mr. Bldridies found the 
normal section of the Laramie sandstones very steeply up- 
turned, resting ou Montana shales, while above them came a 
heavy conglomer ate composed mainly of Archzean debris, but 
containing in addition pebbles recognized as belonging to 
various older sedimentary horizons, such as the Niobrara and 
Dakota Cretaceous, and the Jura. These conglomerates are 
also upturned, but, probably because they come directly in the 
fold, they are less ‘steeply inclined than the Laramie. Angu- 
lar ‘unconformity with the Laramie was not determined. 
Separated from the conglomerate by a gap of 500 feet, in 
which there are no outcrops, are horizontal beds of conglom- 
erate consisting of andesitic pebbles. As the fold is plainly 
abrupt, this position is not evidence of angular unconformity. 

Mr. Eldridge did not have time to trace out either of these 
formations, which, though apparently remnants at the place 
observed, are probably represented elsewhere in the immediate 
vicinity. The fact was established, however, that two forma- 
tions corresponding in stratigraphical position and lithological 
character to the Arapahoe and Denver beds exist near Canon 
City. 

Animas River.—Through the courtesy of Dr. C. A. White 
and his assistant, Mr. T. W. Stanton, I am enabled to state 
that the latter has recently found the formation crossing the 
Animas River about five miles south of Durango, Colorado, 
which is represented as Laramie upon the Hayden map, to 
consist of conglomerates, sandstones and shales, whose material 
is of andesitic rocks, as far as shown by the specimens col- 
lected. By referring to the Hayden atlas of Colorado, sheet 
15, it will be seen that the coal-measures of this region were 
there referred to the Fox Hills, though their identity with the 
normal Laramie measures elsewhere in Colorado is at present 
probably unquestioned by any one. 

On the western bank of the Animas River Mr. Stanton 
found a bed of conglomerate about 200 feet thick resting upon 
the coal-measures with apparent conformity. The specimens 
of this conglomerate collected by him are purplish or yellow- 
ish brown in color, the pebbles are of hornblende- or pyroxene- 
andesite, and the matrix is a gravel of the same character. 
Above the conglomerate are brown sandstones, very similar to 
the Denver sandstones of Table Mountain, and in one stratum 
some fossil leaves were found. The only identifiable species 
collected has been determined by Mr. F. H. Knowlton as 
Magnolia tenuinervis Lx. The specimen first described by 
Lesquereux came from the Denver beds of Table Mountain. 


26 W. Cross—Post-Laramie Deposits of Colorado. 


Since then the species has been repeatedly collected from the 
same beds and has also been detected at Black Butte, Wyom- 
ing. 

That portion of the Hayden map representing the area to 
the westward from the Animas River is based upon the work 
of Mr. W. H. Holmes. In describing the series called the 
Laramie, to which the strata observed by Mr. Stanton evi- 
dently belong, Mr. Holmes usnally refers to them as composed 
of brown sandstones, shales, and dark colored clays. In the 
section on the La Plata River* he assigns a thickness of 800 
feet to the ‘Puerco marls” of Pifion mesa which overlie 
them, and 1120 feet to the coal-measure rocks below, which 
are called Fox Hills. Through the kindness of Mr. Holmes I 
have been allowed to examine his original field-notes in this 
area, and find that the general resemblance of these “ Lara- 
mie” strata to those at Table Mountain near Golden was 
recorded. There is, however, no definite evidence in these 
notes to confirm the generalization suggested by Mr. Stanton’s 
observations that the strata between the “‘ Puerco marls” and 
the coal-measures, west of the Animas River, are equivalents 
of the Denver beds, although the strata noted by him cer- 
tainly occur in that part of the section. 

In an article entitled: “The relations of the Puerco and 
Laramie deposits”+ Professor E. D. Cope states that ac 
cording to the observations of Mr. David Baldwin “the 
Laramie beds succeed [the Puerco] downward, conformably 
it is thought by Mr. Baldwin; and have a thickness of 2,000 
feet at Animas City, New Mexico. [?] They rest on Fox Hills 
marine Cretaceous of less thickness. A few fossils sent from 
time to time by Mr. Baldwin identify the Laramie. This is 
especially done by the teeth of the dinosaurian genus Dys- 
ganus Cope, which is restricted to the Laramie formation 
everywhere. Also by the presence of the genera Lelaps and 
Diclonius, which in like manner do not extend upward into 
the Puerco beds. The Lelaps is principally represented by 
teeth, which resemble those of the ZL. éncrassatus Cope, more 
than those of any other species....” ‘The Dysganus 
agrees with the J. encaustus Cope, which, with the Lelaps 
incrassatus, was described from specimens from the Upper 
Missouri.” 

In recent ‘“ Notes on the Dinosauria of the Laramie’ 
Professor Cope describes a new Dinosaur, Pteropelyx “found 
near Cow Island, Montana, on the Upper Missouri, in 1876.” 
“The genus Pter -opelyx displays characters between the 


* Ninth Ann. Rep. U.S. G. & G. S. 1875, p. 248. 
+ American Naturalist, vol xix, p. 985, 1885. 
¢ American Naturalist, vol. xxiii, p. 904, 1889. 


W. Cross—Post-Laramie Deposits of Colorado. 20 


Hadrosauride and Agathaumide” (= Ceratopside, Marsh). 
He then remarks that it is to be compared with Dysganus. 
Now the original descriptions of the genera Dysganus and 
Diclonius and of the species Lelaps incrassatus are in an 
article entitled: “ Descriptions of some vertebrate remains 
from the Fort Union beds of Montana,”* without any further 
statement in the text as to the geographical or geological posi- 
tion of the occurrence. The new dinosaurian genus Monoclo- 
nius was also described in this article. J/onoclonius is now 
regarded as belonging to the horned Dinosaurs, and four species 
have been named by Professor Cope,t from Montana. One of 
these, J/. sphenocerus, came from near Cow Island, on the 
Missouri, while another, J/. vecurvicornis, came from the 
“Judith River beds” on the north side of the Missouri River 
nearly opposite the mouth of Dog Creek. This last informa- 
tion is found in Professor Cope’s report of the expedition 
during which all of these Dinosaurs appear to have been col- 
lected. + 

From the casual statements of localities and horizons above 
recapitulated it appears that somewhere in the 2000 feet of 
strata assigned by Professor Cope to the Laramie on the 
Animas River several species of Dinosaurs have been found, 
and that they most resemble a fauna collected in “ Fort Union” 
beds near Cow Island, on the Upper Missouri River, in Mon- 
tana, a locality which has furnished at least one species of the 
Ceratopsidee. It is worthy of note that the so-called ‘* Lara- 
mie” section below the Puerco on the Animas River contains 
strata resembling the Denver beds, and also Dinosaurian re- 
mains of types resembling, or associated in Montana with, the 
Ceratopside. Whether the Dinosaurs occur in the Denver- 
like beds remains to be proven. It is certainly of importance 
to discover the character of the vertebrate fauna in beds 
thought to occur conformably below the Puerco. 

Middle Park.—The Hayden atlas of Colorado represents a 
large continuous area of Laramie beds in Middle and North 
Parks, a representation based very largely upon the work of 
the late A. R. Marvine, during the seasons of 1873 and 1874. 
In the annual report for the former year Marvine describes in 

considerable detail the region of Middle Park, but this able 
and lamented geologist died before the notes of the next sea- 
son’s work could be put in shape for publication, and the data 
he then collected are practically lost to science. No publica: 
tion of importance concerning the supposed Laramie beds of 
Middle Park has appeared since Marvine’s report. 


* Proce. Acad. Nat. Sci. Phil., vol. xxviii, p. 248, 1876. 
+ ‘The Horned Dinosauria of the Laramie,” Am. Naturalist, vol. xxiii, p. 715. 
¢ Bulletin, U.S. G. & G. &., vol. iii, p. 565, 1877. 


28 W. Cross— Post. Laramie Deposits of Colorado. 

In his report on Middle Park Marvine describes very clearly 
the excellent section of the Cretaceous formations exposed in 
a synclinal basin cut across by the Grand River for eight 
miles above Hot Sulphur Springs. He also gives detailed 
maps, and sketches from the master hand of W. H. Holmes. 
He well understood the importance of the locality from the 
standpoint attorded by his interpretation of the stratigraphy, 
and since 1873 the “Laramie” of Middle Park has been cited 
as probably the only decided instance of great unconformity 
between this formation and the lower Cretaceous horizons. 

To summarize Marvine’s description of the Grand River 

section, he found the Cretaceous, from the Dakota to the Fox 
Hills, inclusive, exposed on both sides of the syncline men- 
tioned. Then comes a formation occupying the center of the 
shallow syncline, which is described as follows :* “‘ Above the 
Cretaceous No. 5, the next youngest rock is a local occurrence 
of volcanic doleritic material, consisting partially of subaque- 
ous-arranged material—dolerite, tuff, and breccia—and partially 
as accompanying lava-flows; in all, reaching a maximum thick- 
ness of 800 or 900 feet.” This formation | is thereafter usually 
designated as “ Doleritic breccia.” “ Resting upon the latter 
[the breccia] when it occurs, but elsewhere upon Cretaceous 
No. 5, and apparently conformable with the latter, except at 
one point where there is a decided unconformability, is a series 
of beds which reach a thickness of about 5500 feet.” 
“They are composed in part of sandy shales, in places more 
or less argillaceous and quite soft, spaced rather regularly with 
more prominent and characteristic horizons of coarse sand- 
stones, which are often inclined to grits and fine conglomerates. 
The texture of the latter is usually open and not firmly com- 
pacted, while the material of which they are composed is 
characteristically the debris of the Archzean rocks of the moun- 
tains, granitic debris prevailing.” . . . “Impressions of decid- 
uous leaves are quite numerous at favorable localities and small 
isolated patches, and one or two thin seams of carbonaceous 
material were also observed. No other fossils were observed 
in these beds. It has been strongly affected by the last great 
folding accompanying the for mation of the Rocky Mountains, 
portions of it being abruptly upturned, together with the 
underlying sedimentary rocks. In position and character, 
therefore, this group of beds appears to be the equivalent of 
the lignitic group east of the mountains.” 

To the westward of this syncline, in which the formations 
are apparently conformable, Marvine found that the “ lignitic 
beds” above the “ breccia” in fact overlap the latter and rest 
successively on the inclined strata of the entire Cretaceous 


* Seventh Ann. Rep. U.S. G. and G.S., pp. 156, 157. 1874. 


W. Cross—Post-Laramie Deposits of Colorado. 29 


section, the Jura, and the Archean. This was clear in the 
horizontal position of the “ lignitic ” strata of Mt. Bross which 
rest upon upturned Dakota and Ft. Benton strata, and of the 
ridge south of Hot Sulphur Springs. The relationships are 
~ expressed in the Hayden atlas and in the large scale maps 
accompanying Marvine’s report, to which the reader must be 
referred for details. The “thin seams of carbonaceous 
material ” mentioned by Marvine became coal beds in subse- 
quent writings of other geologists, and the fossil plants said 
to have been collected here were identified by the paleobotan- 
ists as “‘ Laramie,” excepting a few which are described by 
Lesquereux without explanatory comment as coming from the 
Green River Eocene. The plainly provisional correlation of 
these beds with the coal-measure horizon east of the moun- 
tains by Marvine has not been questioned until recently. 

It is evident to any one intimately acquainted with the Lar- 
amie proper that the description and statements of Marvine 
do not establish a satisfactory correlation between the Middle 
Park “lignitic” beds and the Laramie. In the light of the 
investigations of the Denver region the unconformity noted 
by Marvine and the thick beds of eruptive material at the base 
of the series suggested a different correlation. In the summer 
of 1889 Mr. George L. Cannon, Jr., of Denver, a geologist 
well acquainted with the local formations, was sent into Mid- 
dle Park by Mr. Emmons to examine the so-called “ lignitic 
formation” of Marvine. On the basis of Mr. Cannon’s work 
it has already been stated by Mr. Emmons that the Middle 
Park series does not correspond with the true Laramie.* In 
October, 1891, the writer visited Middle Park, extending the 
observations of Mr. Cannon and determining still further the 
relationships of the formation in question. A paper giving 
the results of these examinations is in process of preparation, 
but the main features may be here summarized. 

The statements of Marvine as to the unconformity existing 
between the “lignitic” beds and the Cretaceous section are 
very clearly correct. There are faults not noticed by him 
which complicate the local geology very much but they cannot. 
explain the transgression of the newer beds across the entire 
Cretaceous section and to the Archean. The unconformity is 
also shown by an examination of the Cretaceous horizon upon 
which the “doleritic breccia” rests in the section of the 
“breccia spoon,” the syncline above mentioned. It is evident 
that no strata corresponding to the Laramie proper now exist 
in this section. Marvine refers the strata below the “ breccia” 
to the Fox Hills, but gives no special reason for the assign- 


* Orographic Movements in the Rocky Mountains. Bull. G. §. A., vol. i, p. 
281, 1890. 


30 W. Cross 


Post-Laramie Deposits of Colorado. 


ment aside from the general stratigraphical position. Mr. 
Cannon, however, collected a number of fossil shells from the 
shales below the breccia about one mile east of Hot Sulphur 
Springs, and on the south side of Grand river, that is, on the 
western flank of the “ breccia spoon.” These shells were sub- 
mitted to Dr. C. A. White for determination. The following 
species were found at 15 feet below the “ breccia :” Previa 
parkensis White, Scaphites nodosus Owen, sp., Ostrea trans- 
lucida M. & H., Leda ( Yoldia) scitula M. & iBL, Inoceramus 
converus M. & H., I. sagensis Owen, Baculites ovatus Say, B. 
compressus Say ?, Placenticeras placenta, De Kay, sp. and 
Dr. White is of the opinion that they indicate the lower or 
Ft. Pierre division of the Montana rather than the Fox Hills. 

Marvine’s description of the mechanical constitution of the 
“‘lionitic ” series is generally applicable to the part above the 
‘“‘doleritic breccia,’ but as regards the character of the mate- 
rials composing both parts of the series some important cor- 
rections are to be made. In the first place the “ doleritic 
breccia” was unfortunately named, for the rocks composing 
the complex are andesites as far as examined, and the entire 
mass seems to be a water-arranged deposit containing finely 
preserved leaves in some of the most massive parts. The beds 
are very irregular in thickness, and are decidedly thicker on 
the eastern border of the area than on the western. 

As to the great series succeeding the dark massive beds, Mar- 
vine was in error in stating that they consist entirely of 
Archeean debris, for they contain andesitic material in very 
variable amount for more than 2000 feet above the dark brec-. 
cia, and the whole series is evidently one. The character of 
the eruptive material changes somewhat upward in the series, 
lighter colored and more acid rocks prevailing. Many beds in 
the terraces north of Grand river are sandstones or grits con- 
sisting of quartz and feldspar to a strongly prominent degree 
but none are entirely free from andesitic fragments, and con- 
glomerates composed very largely of eruptive material often 
succeed quartzose sandstones. The strata in the divide be- 
tween Middle and North Parks belong to the same series, 
according to Marvine. These were not visited by the writer, 
but the beds shown in the high ridges some eight miles north 
of Grand river, east of Whiteface Mountain, still earry a large 
amount of pinkish andesitic material. The same eruptive 
constituents were found in the strata of Mt. Bross, and of the 
ridges south of Hot Sulphur Springs ; in fact, no beds of this 
complex were found to be wholly free from materials of this 
character. 

No animal remains are reported from the series by Marvine, 
nor were any found by either Mr. Cannon or the present 


W. Oross—Post-Laramie Deposits of Colorado. 31 


writer. Fossil plants are quite numerous in all parts of the 
series. Of those collected by the members of the Hayden 
survey a large majority came from Mt. Bross, and a few from 
distant localities on Willow and Troublesome Creeks, from 
strata referred to the same general horizon by Marvine. This 
material has been described by Lesquereux* but there has been 
such a serious confusion of localities in also assigning a num- 
ber of other fossil plants to Middle Park, that little use can at 
present be made of these identifications. Collections of fossil 
plants made by Mr. Cannon and the writer in various horizons 
of this series have been provisionally identified by L. F. Ward 
and F. H. Knowlton. From these data it can be said that out 
of about 35 well defined species more than 20 are known in 
the Denver beds of Table Mountain, at Golden, a closer cor- 
respondence of floras than is shown with any other horizon. 
Until the investigation of the Laramie flora now in progress 
has been completed it is useless to enter into more definite 
comparisons. 

The so-called Laramie beds of Middle Park seem from the 
foregoing facts to be the equivalent of the Denver beds. No 
strata corresponding to either the Arapahoe or Laramie proper 
are known in Middle Park, and the invertebrates collected by 
Mr, Cannon indicate that the upper part of the Montana is 
also wanting in the vicinity of Hot Sulphur Springs. Present 
information gives little ground for an estimate of the extent 
to which the missing formations were once developed in this 
region. 


Age of the Lake-bed Deposits. 


The facts of stratigraphy and lithology which have been 
recited show that in Colorado the great conformable series of 
Cretaceous formations ended with the coal-bearing Laramie 
strata. Deposition plainly ceased in this area because conti- 
nental elevation, which had long been in progress, finally 
caused the retreat of the Laramie seas. The magnitude of 
this elevation, the time interval involved, and the question as 
to the identity of this particular movement with the great 
movement generally supposed to mark the ending of Mesozoic 
time in the Rocky Mountain area, are clearly problems of 
great importance. Confining discussion at present to the in- 
disputable evidence of the deposits described, it is clear that 
when sedimentation began again in the region concerned it 
was in comparatively small seas or lakes. In the pebbles of 
the Arapahoe, Cafion City, and Ohio Creek beds, is found 
proot that adjacent landmasses consisted in part of upturned 
sedimentary rocks, and in the first named is the record of the 


* Monographs of the Hayden Survey, vol. vi, Tertiary Flora. 


32 W. Cross—Post-Laramie Deposits of Colorado. 


slow erosion of 14,000 feet of strata, from the Laramie down 
to the “ Red beds” of the Trias.* 

Succeeding the first period of lake-beds came a time of 
great voleanie outbursts over a very large area. The length 
of geologic time occupied may not have “been very great, but 
the extent of country in which eruptions occurred at this time, 
and the great variety of lavas found in the Denver and Middle 
Park beds, argue for the decided importance of the event as a 
dynamic manifestation, The position of the Middle Park 
beds on the edges of the Cretaceous section below the Ft. 
Pierre, proves a period of erosion there which was no doubt 
contemporary with the Arapahoe epoch though its record is 
not known in deposits. Marvine assigns a thickness of over 
6000 feet to the Middle Park beds (including the “ breccia”), 
characterized through the lower half at least by volcanic ma- 
terial,—striking testimony to the extent of the eruptions and 
the duration of the period of deposition, which must have 
been one of subsidence, approximately equalling the thickness 
of beds deposited. 

The question as to the age of the formations under discus- 
sion is the question as to the length and importance of the 
periods in which the events clearly recorded in their sediments 
took place. From the standpoint of structural and physical 
geology an adequate chronology will distinguish or separate 
this period from that of the coal-bearing Laramie; but accord- 
ing to the principles of geology the measure of the geologic 
time involved is to be sought in the fossils,—in a comparison 
of the life of the two periods which are to be distinguished. 
But at the very outset of such an attempt it becomes evident 
that a very large number of fossils said to oceur “in the Lara- 
mie” are not at present available for such a purpose. This 
difficulty arises chiefly from the fact that the stratigraphical 
position of the beds of many localities where ‘ Laramie” 
fossils have been found has not been at all clearly determined. 

In their recent discussions of orographic movements Messrs. 
Emmons and Hills have treated the post-Laramie disturbance 
as that closing Cretaceous time. The formersays: ‘ With the 
exception of the great unconformity between the Archzean 


* The lithological evidence upon which the distinction of the local formations 
above mentioned has been largely made will probably make little impression 
upon some readers. It is a striking fact in many observations of the past and of 
the present in the western region, that the material constitution of coarse grained 
sandstones and conglomerates has been and is now practically ignored. But if a 
conglomerate in the apparently conformable Cretaceous section contains pebbles 
of Niobrara limestones, of the extremely characteristic Dakota conglomerate, of 
red Jurassic or Triassic sandstone, or of Carboniferous chert. a definite unconfor- 
mity of great magnitude is made known which does not require proof in visible 
angular unconformity or in the fossils, though the latter undoubtedly will confirm 
it when they are known in sufficient detail. 


W. Cross—Post-Laramie Deposits of Colorado. 33 


and all overlying sediments, . . . no movement has left such 
definite evidence as that which followed the deposition of the 
coal-bearing rocks, to which the name Laramie has by univer- 
sal consent been applied.”* And while Mr. Hills thinks that 
some of the effects hitherto ascribed to the post-;Laramie 
movement belong to that following the Bridger Eocene, his 
conclusion in regard to the Arapahoe, Denver and equivalent 
beds, is as follows: ‘¢ From all the evidence available it appears 
that stratigraphically these beds are not Laramie, since to refer 
them to the Cretaceous would bring us face to face with the 
necessity of conceding an earlier date than post-Cretaceous to 
the Rocky Mountain revolution. Nor are they, paleontologi- 
eally, a part of the recognized Eocene. Whence we must con- 
elude that they are not assignable to either of these terranes, 
but should be regarded as transition beds deposited subsequent 
to the beginning of the post-Cretaceous movement, or probably 
during its progress and hence of post-Laramie age.’’+ 

The Denver beds contain a very large and well preserved 
fossil flora. So do the coal-measures of the Laramie in the 
same field, and more than 160 species have been described 
from this district by Lesquereux.t It has already been 
shown§ in describing the Denver beds that from the statements 
of this author only a very small percentage of the described 
species can be definitely assigned to one of the two plant- 
bearing horizons, nor is the desired information to be found on 
the labels or in the catalogue of the National Museum where 
the original specimens are now deposited. Examination has 
also shown a lamentable inaccuracy in designation of localities 
for the fossil plants of various other localities assigned to the 
Laramie. This is true especially of the plants from the Mid- 
dle Park beds, as has been mentioned. The existing confusion 
is so great that no credible table can now be constructed from 
published data to show, excepting in a most general way, 
whether there is or is not a noteworthy difference between the 
known flora of the Denver and Middle Park beds and that of 
the Laramie proper. But on the basis of new and extensive 
collections from known horizons a thorough revision of this 
portion of the Laramie flora is now in progress in the paleo- 
botanical department of the Geological Survey. Until the 
results of this revision can be made public a discussion of the 


* Orographic movements in the Rocky Mountains, Bull. G.S. A., I, p. 285, 1890. 

+ Orographic and structural features of Rocky Mountain geology, Proc. Colo. 
Sci. Soc, vol. iii, Part III, p. 397. 

¢ Monographs of the Hayden Survey: vol. vii, ‘‘The Tertiary Flora;” vol. 
vill, ‘‘ The Cretaceous and Tertiary Floras;” also, Bull. Mus. Comp. Zool, Har- 
vard College, vol. xvi, No. 3, 1888. 

§ This Journal, vol. xxxvii, p. 272, 1889. 


Am. Jour. Sco1.—TairD Series, Vou. XLIV, No. 259.—Juty, 1892. 
3 


34 W. Cross—Post- Laramie Deposits of Colorado. 
bearing of fossil plants in determining the age of the Denver 
and allied deposits is useless. 

The few invertebrate fossils found in the Denver beds are, 
according to Dr. C. A. White,* of no special value in the 
present case. Viviparus trochiformis and Goniobasis tenwi- 
carinata are the only specifically identifiable forms as yet 
known, while imperfect forms referable to Corbicula, Physa, 
and Unio accompany them. 

The vertebrate fauna known from the Denver and Arapa- 
hoe beds is small, but its character is such as to raise some very 
broad questions for settlement before its value for purposes of 
detailed correlation can be determined. At the time the Den- 
ver and Arapahoe formations were described a considerable 
number of fossil bones had been found, and since that time 
additional material has been obtained by Mr. G. L. Cannon, Jr. 
All the material collected has been examined by Professor O. 
C. Marsh, who identifies fragments of turtles, crocodiles, and 
dinosaurs.t Only the latter are of especially recognized im- 
portance in this case. They belong for the most part to the 
remarkable new family, the Ceratopsidee. of which so many 
wonderful forms have been described within the last three 
years, and it is necessary at this point to pass in review certain 
phases of the discoveries made by Professor Marsh, and the 
facts stated in the publications concerning them. 

In aseries of articles in the American Journal of Science 
beginning December, 1888, Prof. Marsh has described a won- 
derful new fauna said to occur in the Laramie of Montana, 
Wyoming and Colorado, the two most important elements of 
which are a group of horned Dinosaurs forming a new sub- 
order, the Ceratopsia, and a large number of small mammals. 
The new Dinosaurs are closely related to Stegosaurus in many 
features of the skeleton, but the skull and dermal armor have 
become strangely modified and possess marked characteristics 
“not before seen in the Dinosauria.” With the exception of 
a few isolated bones and teeth mentioned by Cope the mam- 
malian fauna associated with these Dinosaurs is the first to be 
discovered in the American Cretaceous, and is closely allied to 
that known in the Jura, and widely different from that charac- 
terizing the Wasatch Eocene. 


* Cited in article describing the Denver Formation, this Journal, vol. xxxvii, p. 
279. 

+ The fossil from the Denver beds originally described by Professor Marsh as 
Bison alticornis is now regarded by him as belonging to Ceratops (this Journal, 
Xxxvill, 174, 1889). 

{ The writer wishes to acknowledge the courtesy and kindness of Professor 
Marsh in showing him a large number of the remarkable and important forms 
which have been found in the Ceratops beds, and in explaining the great prob- 
lems they present to the evolutionist, together with their apparent bearing upon 
questions of historical geology. 


W. Cross—Post-Laramie Deposits of Colorado. 35 


In attempting to correlate the new formations of the Denver 
field by means of their vertebrate fossils it is necessary to 
know the horizon or horizons which have furnished the large 
new fauna recently described. A review of the papers published 
by Prof. Marsh shows, however, that except for fossils which 
came from the Denver region no detailed evidence is given as 
to the stratigraphical or geographical position of beds contain- 
ing any of the fossils described. There are only the general 
statements that they “come from the typical Laramie of. 
Wyoming” or “of Montana.” All localities are correlated as 
belonging to one general horizon, ‘“‘the Ceratops beds,” and 
the assertion is made that: ‘This horizon is as strongly 
marked as that of the Atlantosaurus beds, and has now been 
traced for nearly eight hundred miles along the eastern base of 
the Rocky Mountains.” And as to stratigraphical relation to 
lower beds, “Toward the north, it is underlaid by marine 
Cretaceous strata containing Fox Hill fossils, but farther south, 
various older formations are found immediately beneath it.” * 
It certainly seems natural and it may almost be said probable 
that such a new and specialized group of animals should char- 
acterize a well marked geological horizon. But as far as the 
actual position of the Ceratops beds has been described, 
namely, in the Denver region, they are separated from the 
normal Laramie by a great unconformity, and it remains to be 
demonstrated that the new forms occur at all in the Laramie 
proper. It is believed to be a fact that in all the great Lara- 
mie formation of Colorado, where it has been studied more 
thoroughly and connectedly than anywhere else, no represent- 
atives of the Ceratopsidee have been found ; and that the same 
is true of the adjacent connected deposits in New Mexico and 
Utah. None of the species described by Prof. Marsh has been 
stated to come from the Laramie coal-measures of southern 
Wyoming, but it seems probable that the historic Dinosaur 
called Agathaumas by Cope, the discovery of which at Black 
Butte in 1872 played such an important part in deciding opin- 
ion as to the Cretaceous age of the Laramie, may prove to be 
of importance in the present discussion also. It is now 
thought by both Cope + and Marsh ¢ that this form is a horned 
Dinosaur. If this is true the Ceratopside are represented to 
the west of the Front range in what have been called typical 
Laramie strata by some authors. But it happens that the 
Black Butte locality is one concerning which geologists have 
differed considerably in their observations and opinions. A 


* This Journal, vol. xlii, p. 338, 1891. 
+ Amer. Naturalist, xxiii, p. 715, 1889. { This Journal, xliii, p. 83, 1892. 


36 W. Cross 


Post-Laramie Deposits of Colorado. 


succession of several thousand feet of strata in this region has 
been referred to the Laramie, but Major Powell claims to have 
found an important physical break below the horizon contain- 
ing the Agathaumas, as he expressly states,* and if this is true 
this Dinosaur may actually occur here in strata contempora- 
neous in time with the Arapahoe beds. In any case it remains 
to be proven that the ‘“ Ceratops beds” of Marsh, from the 
“eastern base of the Rocky Mountains” are stratigraphical 
equivalents of the horizon at Black Butte in which the Agath- 
aumas was found. 

This brings us to the questions: On what ground does 
Prof. Marsh | assign the Ceratops beds to the Laramie ? and, 
What does the Laramie properly embrace? The assignment 
rests, as far as published evidence goes, on the presence of a 
new fauna of strong Mesozoic affinities, in beds more recent 
than the Fox Hills, and unknown, with the possible exception 
noted above, in strata known to occupy the stratigraphical po- 
sition assigned to the Laramie in its original definition. The 
general statement of Prof. Marsh that the Ceratopsidz he has 
described ‘are found in the typical Laramie of Wyoming” is 
misleading in this sense, that, to any one acquainted with the 
literature of the subject, “ the typical Laramie of Wyoming ” 
must always be that formation in southwestern Wyoming to 
which Mr. Clarence King first applied the name, or its demon- 
strated equivalent. And it seems opportune to quote here the 
definition of the Laramie given by that author. After explain- 
ing, that on consultation with Hayden and without compro- 
mising differences of opinion as to the age of the beds in 
question, a common name had been adopted, he says: ‘ Ac- 
cordingly ... it was amicably agreed between us [Hayden 
and King] that this series should receive the group name of 
Laramie, and that it should be held to inelude that series of 
beds which conformably overlies the Fox Hills.’ + Experi- 
ence since this definition was set up has shown that over a 
very large area there is a great and important formation to 
which that definition strictly applies. And evidence continu- 
ally accumulates to prove that this formation, which certainly 
must be called the Laramie, was the last of the series of con- 
formable deposits belonging to the Cretaceous. 

Returning to the question as to the evidence concerning the 
stratigraphical position of the ‘Ceratops beds,’ it is to be 
noted that in Montana and Wyoming they are said to oceur on 
the eastern flank of the Rocky Mountains, in a district which 


* Geology of the Uinta Mountains, p. 72. 
+ Final reports of the Fortieth Parallel Survey, vol. i, Systematic Geology, 
p. 331. 


W. Cross—Post-Laramie Deposits of Colorado. 37 


has not been carefully explored as yet except for vertebrate 
fossils. And marked angular unconformity at the base of 
these beds might not be distinguishable if the shore line was 
too far removed from the localities examined. But even the 
general statement of Prof. Marsh seems to indicate a great 
actual unconformity, for he says, in the sentence quoted above, 
that, in some places not specified, ‘“ various older formations 
are found immediately beneath it” (i. e. the Ceratops horizon, 
ealled ‘the typical Laramie’). As invertebrates and plants 
are stated to be associated with the vertebrate fauna it seems 
quite necessary that their testimony, as well as all available 
stratigraphical and lithological details, should be given, before 
the beds in question can be satisfactorily correlated. 

The cited statement of Prof. Marsh that “the Ceratops beds 
have now been traced nearly eight hundred miles along the 
eastern flanks of the Rocky Mountains” implies the actual 
connection of the formations of the Denver field with that 
containing the new fauna in Wyoming. But the area of the 
Denver beds is known to be quite limited, and the Arapahoe 
beds on the plains east of Denver are thin and erosion has 
entirely removed them in many places, exposing the under- 
lying Laramie. It is, however, possible that they thicken again 
farther out on the plains, or reappear to the northward beyond 
the Platte valley. If the investigations of Prof. Marsh have 
actually connected the Ceratops beds of Wyoming with the 
Arapahoe beds of Colorado, this fact is of great importance as 
fixing the stratigraphical position of the Ceratops horizon as 
post-Laramie. If, however, the Ceratops beds of Wyoming are 
contemporary with the true Laramie, then they do not belong 
to the same epoch as the Denver and Arapahoe beds. 

The above considerations show that the vertebrate fossils of 
the Arapahoe and Denver beds cannot at present be used as an 
argument either for or against the proposed separation of 
these lake-beds and their equivalents from the Laramie, be- 
cause the new fauna recently described has not been identified, 
in published statements at least, in strata satisfactorily iden- 
tified with the true Laramie on other ground than that of the 
new fossils themselves. _ It is clearly suggested by the known 
evidence that the new family of Dinosaurs may be found to 
be specially characteristic of the epoch to which the lake-beds 
described belong, as distinctive from that of the Laramie 
proper; that their remarkable specialization may have taken 
place lar gely asa result of the changed conditions following 
the great orographic movement closing the Laramie. Until 
more is known about the distribution of the Ceratopsidee and 
their immediate ancestors in the Cretaceous series of forma- 


38 W. Cross Laramie Deposits of Colorado. 


& 


tions, they certainly cannot be used as diagnostic fossils for 
any horizon. 

The facts of stratigraphy and lithology demand that the in- 
terval between the Laramie and the lake-bed deposits should 
be recognized as a very important one. The known fossils do 
not aid us in determining the importance of that interval 
because their distribution with reference to it is so imperfectly 
established. Such seems to be the necessary verdict from the 
examination of the direct evidence available at present. Much 
collateral testimony might be introduced into this discussion, 
from observations in remote districts, but it seems undesirable 
and premature to consider such evidence at this time. Some 
of the reasons for this conclusion will appear in the more 
general discussion to follow. 

Assuming that the lake-beds described in this article should 
be separated from the Laramie, the question as to whether they 
are Tertiary or Cretaceous is quite another problem. It was 
argued in the article on the Denver beds that the establish- 
ment of a profound orographic movement in the period sue- 
ceeding the Laramie, followed by extensive and long-continued 
volcanic outbursts, indicated that the deposits of the Arapahoe 
and Denver epochs should be assigned to the Eocene. This 
was in harmony with the ideas to be found in all previous 
speculations as to what actually closed the Cretaceous period. 
At the time the article in question was written a few bones 
had been identified by Professor Marsh as belonging to Dino- 
saurs and other vertebrate forms of Mesozoic types, but the 
fact that these animals had survived a period of various 
dynamic disturbances of great magnitude seemed then to 
indicate that they were straggling survivors into earliest 
Eocene time rather than that the movement should be placed 
in the Cretaceous. 

The facts presented in this paper make it plain that the dis- 
cussion of this question involves now a discussion of the 
broader one as to the character and position of the line to be 
drawn between Mesozoic and Cenozoic deposits in the Rocky 
Mountain region, and as to the criteria to be used. And at 
present there is such a decided conflict between the results 
reached in applying different criteria that the necessity for 
more information on many points is clear. In illustration of 
this necessity a few of the recently expressed opinions upon 
this subject will be quoted. 

Professor Marsh* in a recent publication on the Cretaceous 
mammalia and their associated vertebrate fossils, occurring 
in the Ceratops beds—“the Laramie of Wyoming ”—says: 


* This Journal, vol. xliii, p. 249, March, 1892. 


W. Cross—Post-Laramie Deposits of Colorado. B39 


“These remains are not transitional between Mesozoic and 
Tertiary forms, but their affinities are with the former beyond 
a doubt; thus indicating a great faunal break between the time 
in the Cretaceous when they lived and the earliest known Ter- 
tiary, or between the Ceratops horizon and the Coryphodon 
beds of the Eocene Wasatch. The lower division of the 
Coryphodon beds, or lower Wasatch (Puerco), is clearly 
Tertiary, and the great break is between this horizon and the 
Ceratops beds of the Laramie.” Concerning the abundant 
faunas of the two horizons, ‘the more the two are compared 
the stronger becomes the contrast between them. Instead of 
placing them close together, as some geologists seem inclined 
to do, it will be more profitable in future to search for the 
great series of intervening strata containing the forms that 
lead from one to the other.” “ Bearing in mind all that is 
known to-day of the development and succession of vertebrate 
life in America, from the early Silurian on to the present time, 
it is safe to say that the faunal break as now known between 
the Laramie and the lower Wasatch is far more profound than 
would be the case if the entire Jurassic and the Cretaceous 
below the Laramie were wanting.”’* 

Professor E. D. Copet in his “Synopsis of the Vertebrate 
Fauna of the Puerco series” (1888) considers the Puerco 
fauna as widely distinct from that of the Wasatch, and points 
out that among 106 species of vertebrates known from the 
Puerco not one is found either in the Wasatch or in the Lara- 
mie; that some important Mesozoic types end in the Puerco ; 
that ‘“‘two orders universally present in the EHocenes, the Peris- 
sodactyla and the Rodentia, are wanting from the Puerco”; 
and that many Puerco forms are plainly the ancestors of 
Eocene types. Shortly before this publication Professor 
Copet had assigned the Puerco and Laramie to the ‘“ Post- 
Cretaceous” as expressing their relationship better than to 
class one with the Eocene and the other with the Cretaceous. 
It is worthy of note that the Puerco was assigned to the 
Kocene by Professor Cope§ as recently as 1883. 

Professor Marsh refers the Puerco to the lower Wasatch= 


* Since the completion of this-article Prof. Marsh has announced the presence 
of Ophidians and true Lacertilians with the gigantic dinosaurs of the Ceratops 
beds, ‘tin the Laramie of Wyoming.” No serpents have hitherto been found in 
America below the Eocene. (Notice of new reptiles from the Laramie Forma- 
tion. This Journal, vol. xliii, p. 449, May, 1892.) 

+ Trans. Am. Phil. Soc., vol. xvi, pp. 298-361. 

¢ The Relations of the Puerco and Laramie Deposits. Amer. Naturalist, vol. 
ix, p. 985, 1885. The Mesozoic and Cenozoic Realms of the Interior of North 
America. Ibid, vol. xxi, p. 445, 1887. 

§ Monographs of the Hayden Survey, III, Tertiary Vertebrata, Book I, p. 4, 
1883. 


40) W. Cross—Post-Laramie Deposits of Colorado. 
Lower Coryphodon beds, but Professor Cope says, in 1883: 
“ Coryphodon is, so far, unknown,” and in his last synopsis of 
the Puerco fauna (loc. cit.) he does not include that form. 

Regarding the first mammalia described by Prof. Marsh 
“from the Laramie” Prof. Cope* has said: ‘These species 
are of identical character with the Puerco mammals, although 
there is no species identical with any in the Puerco, where 
there is not a single Cretaceous reptile. The mammals of the 
Laramie are, like the saurians, rather Cretaceous than Tertiary ; 
but the character is not as pronounced.” 

The question as to the relations of the Laramie to the 
Eocene has recently been reviewed by Dr. C. A. White in the 
Correlation Essay on the Cretaceous prepared for the Fifth 
International Congress of Geologists,t and with the result 
that the Laramie ‘is held to represent both the close of the 
Cretaceous and the beginning of Tertiary time,” with a proba- 
bility that in certain known areas there has been continuous 
sedimentation from the coal-bearing Laramie through to the 
Wasatch Eocene or it equivalents. The molluscan fauna is 
said to favor such a conclusion. 

Prof. J. S. Newberry ¢ has recently expressed the decided 
opinion that the diverse views of geologists concerning the 
Laramie have in large part “arisen from the fact that many 
writers on the subject have combined two distinct formations 
in the Laramie and have called them one, when they have 
almost nothing common, belong to different geological systems, 
and should never have been united.” He then assigns the 
Fort Union beds of Montana to the Eocene, and the remainder 
of what has been called Laramie to the Cretaceous, asserting 
that the floras of the two “are totally distinct.” 

In discussing this paper Prof. L. F. Ward claimed that the 
Ft. Union flora was not absolutely distinct from that of the 
Laramie though very different, and that it might well be con- 
sidered as Cretaceous. 

Prof. Marsh states€ that “ the Ft. Union Eocene beds on the 
Upper Missouri” rest immediately upon the ‘“ Ceratops beds.” 
It would be interesting to know the flora of the ‘“Ceratops 
beds” and the.vertebrate fauna of the ‘‘ Ft. Union beds” in 
this region. ~Prof. Cope has published a “ Description of some 
vertebrate remains from the Ft. Union beds of Montana,”| 


* Bull. Geol. Soc. of Am., vol. i, p. 532 (Dec. 1890). In discussion of a paper 
by J. S. Newberry, The Laramie Group. 

+ Correlation Papers. The Cretaceous, Bull. 82, U. S. Geological Survey, 1891. 
Compare pp. 262. 

uke Laramie Group, Bull. Geol. Soc. of Am., vol. i, p. 524. 

§ This Journal, xlii. p. 336. 

|| Proc. Acad. of Nat. Sci. of Phila., vol. xxviii, p. 248, 1876. 


W. Cross—Post-Laramie Deposits of Colorado. 41 


but without any statement of locality or stratigraphical data, 
so that his paper stands rather as an illustration of the common 
manner in which uncertainty and confusion have been intro- 
duced into the literature of the Laramie, rather than as evi- 
dence that Dinosaurs occur in beds containing the Ft. Union 
flora. 

From these recent expressions of opinion concerning the 
Laramie in its comprehensive sense and of the period of time 
between the marine Cretaceous and the Puerco or lower 
Eocene, it is clear that paleontologists have sought to correlate 
the formation and characterize the period from the evidence 
of the flora or of a particular fauna. In some cases at least 
the opinion has been rendered upon biological grounds alone, 
and has been announced with great confidence, often with but 
the slightest reference to the results reached upon other pale- 
ontological evidence or to contrary opinions from the same 
evidence, with little regard for known facts of stratigraphy, 
and still less for the very important fact of utter ignorance 
concerning the actual relationships of some of the places, hori- 
zons, and faunas or floras dogmatically correlated. This vari- 
ance of opinion is a natural result of the methods used, yet no 
one will dissent from the proposition that a correct knowledge 
of the history of this interesting period cannot be reached 
until all classes of evidence are carefully compared on a basis 
of unbiased and accurate observations in all directions. 

The facts brought together in this paper point to one impor- 
tant epoch in the period under discussion which has not been 
duly recognized, to say the least. Its broad intrinsic impor- 
tance has yet to be determined, and the writer wishes to dis- 
tinctly express his appreciation of the fact that that importance 
must ultimately be measured in great degree through the effect 
exercised by the conditions of that epoch upon the life of the 
time. But the great importance of the orographic movement 
which has been identified, in relation to the physical history of 
a very large district, must also be borne in mind. 

In conclusion, the writer wishes to advocate the restriction 
of the term Laramie, i in accordance with its original definition, 
to the series of conformable beds succeeding the marine Mon- 
tana Cretaceous, and the grouping of the post-Laramie lake- 
beds described, with their demonstrated equivalents, in another 
series to which a comprehensive name shall eventually be 
given. This course has already been proposed by Mr. Hills in 
his conclusion which has been cited (p. 33). The question as 
to whether the series shall be referred to the Cretaceous or to 
the Eocene cannot be finally settled until the various conflict- 
ing elements of the evidence have been adjusted on a basis of 


49 Wells, Wheeler and Penfield—Alhali-Metal 


further and more exact information. But even if we assume 
that the lake-beds are Cretaceous, there remains a sutticient 
argument for restricting the scope of the term Laramie in the 
fact that to include the two or three series of deposits, with 
the long intervals between them, under one group name would 
make the latter ee comprehensive and important in the 
scale of Cretaceous sub-divisions.* 


Art. [1V.—On the Alkali-Metal Pentahalides; by H. LI. 
We tts and H. L. WHEELER Wath their Crystallography; 
by S. L. PENFIELD. 


In the course of our investigations on the alkaline triha- 
lides,t the compounds CsCl.Cl,I, RbC].Cl,[ and KCl. Cl,I 
were encountered. The potassium compound had been de- 
scribed many years ago by Filhol.t This investigator pre- 
pared also the body NH,Cl.Cl,I and obtained a similar mag- 
nesium compound, probably MgCl],.2Cl,l.5H,O. He failed 
in his attempts to make analogous compounds with sodium and 
a considerable number of the other common metals. 

It was evident from the peculiar behavior of cesium tribro- 
mide and triiodide, mention of which was made in one of our 
previous articles,§ that a still higher bromide and iodide 
existed. These have now been identified as pentahalides. 

In addition to these bodies we have prepared the sodium 
and lithium analogues of Filhol’s salt. They differ from all 
the other polyhalides that we have studied in containing water 
of crystallization. 

A large number of other alkaline pentahalides are theoreti- 
cally possible, but, although we have made numerous experi- 
ments with the view of making the most promising of these, 


* Canadian geologists have long recognized several important divisions in 
what they have called the Laramie. As their divisions cannot be accurately cor- 
related as yet with those in the United States, owing to the very meagre infor- 
mation concerning the great complex of supposed Laramie strata in Montana, the 
writer has avoided a consideration of those points in this paper. It seems not 
unlikely that the divisions of the group made on combined stratigraphical and 
paleontological grounds in Canada will agree with those to be reached finally in 
this country. The ‘*Kdmonton” and ‘St. Mary River” beds seem to correspond 
to the Laramie proper, and the “ Paskapoo” and ‘‘ Poreupine Hills” beds to the 
Fort Union, but it is less clear that their ‘Willow Creek” or Middle Laramie of 
certain areas is equivalent to the post-Laramie lake-beds here described. ‘ The 
uplifting of the Rock Mountains” is said by Mr. J. B. Tyrrel] to have taken place 
‘“at the close of the Edmonton period.” (Report on a part of Northern Alberta, 
p. 137, Ann. Rep. Geol. and Nat. Hist. Survey of Canada for 1886), 

+ This Journal, III, xhu, 17 and 475. 

tJ. Pharm., xxv (1839), 431. 

§ This Journal, III, xliii, pp. 24 and 27. 


Pentahalides, with their Crystallography. 43 


we have been unable to prepare them. It may be stated that 
special efforts were made to obtain potassium and rubidium 
pentaiodides. 


Csi... 


This is produced, in an impure state as a black liquid solidi- 
fying at about 738°, by treating cesium triiodide with hot 
water and also by treating solid iodine with a hot solution of 
czsium iodide. Artificial mixtures of caesium trilodide and 
iodine, representing compositions varying from CsI, to Csl,, 
all melt at a uniform temperature of about 73°. It is evident 
from this that the composition of the black liquid cannot be 
determined from its melting-point. 

Cesium triiodide, which is readily soluble in alcohol, be- 
comes much more soluble in that liquid in the presence of two 
atoms of iodine to the molecule. A very concentrated solu- 
tion of this kind gives crystals of the pentaiodide by cooling, 
but a much better product is obtained by concentration over 
sulphuric acid, using a slight excess of iodine to allow for loss 
by volatilization. The crystals are well formed and have a 
brilliant black color. They can be distinguished from crystals 
of iodine, which may separate if too much of this substance 
has been used, by their brittleness as well as their form. The 
substance melts, not sharply, at 73°. It loses-iodine on expo- 
sure about as rapidly as iodine itself volatilizes. It does not 
contain water or alcohol. 

Samples of the crystals quickly dried with paper gave the 
following results on analysis : 


Made by By evaporation, Calculated 
cooling. Separate products. for CsI. 
Crsiumme a. 15°20 20°96 16°02 17°32 
liodinee Sa se Le Ls A see 82°68 
Cs Br. 


When a concentrated solution of cesium bromide is shaken 
up with a large excess of bromine there is no separation of 
cesium tribromide, as is the case when the theoretical amount 
of bromine is used. A large part of the cesium bromide 
goes into solution in the liquid bromine, and on taking up a 
sufficient quantity of cesium bromide this solution becomes 
lighter in color than pure bromine. 

A solution of cesium bromide in bromine, made in the 
manner above indicated, was allowed to evaporate spontane- 
ously at a temperature below 0°. A dark red solid finally 
separated and it was prepared for analysis by pressing with 
papers at the same low temperature. After the adhering 
bromine had been removed the substance gave off bromine- 
vapor very rapidly. 


ao Wells, Wheeler and Penfield—Alkali-Metal 


Calculated 

Analysis gave for CsBr;. 

@pecsiumss eee 29°93 24°95 
IBOmine wes eee pe 75°05 


The analysis corresponds with the formula CsBr, as well as 
could be expected considering the great instability of the com- 
pound. 


CsCl. CLL. 


This substance can be prepared by dissolving 40 g. of cxesium 
chloride in a mixture of 600 c¢.c. of water and 200 ce. of 
concentrated hydrochloric acid, adding 30 g. of iodine (one 
atom), passing chlorine to saturation, meanwhile keeping the 
solution warm enough to dissolve any of the compound which 
separates in the form of a yellow precipitate, and finally cool- 
ing to crystallization. The hydrochloric acid is used to pre- 
vent the simultaneous deposition of an acid czesium iodate. 


Calculated 
Analysis gave. for CsCl. ClsI. 
Cesium ee Od 33°09 
Chiorinewe see 34°79 35°32 
Fodineate ee aie ay lout 31°59 


The crystals are of a pale orange color. They are in the 
form of slender prisms, usually in parallel position forming 
plate-like groups. The body is sparingly soluble in water and 

can be recrystallized from it without much decomposition. It 

is nearly permanent in the air. On heating it is apparently 
converted into CsCl. CH, for it melts like that substance at 
238° (uncorr.) in the open capillary tube. 


RbCl. CLL 


This body can be conveniently prepared by adding 40 g. of 
iodine to a nearly saturated solution of 38 g. of yubidium 
chloride and passing in an excess of chlorine. The solution 
becomes warm from the reaction, and on cooling large orange- 
yellow plates are deposited. 


Caleulated 
Analysis gave for RbCl. ClsI. 
Riuibidiumpsesssee- ene 24°19 23°63 DAV. 
Chilonines aes ae eee 39°00 Sta 40°05 
lodinewcs-s2 se 35:31 she 35°83 


The compound is soluble in alcohol, unaffected by ether. 
When rapidly heated in an open capillary tube it melts at 
218° (uncorr.) undergoing some decomposition, and becomes 
completely white at ‘about 270°. These numbers agree quite 


Pentahalides, with their Crystallography. 45. 


closely with the melting and whitening points of RbCl. CII. 
so that it is evident that there is a loss of two atoms of chlo- 
rine before much further decomposition takes place. In view 
of this fact it is remarkable that, when samples of RbCl. C1,I 
and RbC!. CII were exposed to the air side by side for three 
months, the compound containing the greater amount of 
chlorine was almost completely decomposed while the other 
remained nearly unchanged. It is therefore probable that 
RbCI. Cl, decomposes at ordinary temperatures by losing Cl,I 
as a whole, while by heating another decomposition takes 
place. 


KCl. CLE 


This compound, first described by Filhol, has been prepared 
for the sake of studying its crystalline form. It is easily 
made by the method which has been given for the correspond- 
ing rubidium compound. The crystals obtained by cooling are 
in the form of very slender needles, but by evaporating the 
mother-liquor from these at ordinary temperature thicker 
prisms suitable for measurement can be obtained. 


Calculated 


Analysis gave for KCl. OlsI. 
iPotassiumye 222222 11°98 12°66 
Chloninewes. 45°31 46°10 
to diinek ee 22 est 42°50 44°23 


NaCl. Cl,1.2H, 0. 


To prepare this substance, sodium chloride and iodine in the 
calculated proportions are mixed with insufficient water to dis- 
solve the sodium chloride even on heating, chlorine is added 
to saturation at a gentle heat and the liquid is filtered while 
still warm. The solution on cooling to a low winter tempera- 
ture gives a crop of slender needles, but better crystals are 
obtained by evaporation in a desiccator. Some of the latter, 
quickly dried on paper, gave the following results on analysis: 


Caleulated 
Found, for NaCl. Cll. 2H.0. 
SOM eee ss te oaks 701 
CGhiorinees. 222 4 42.92 43°29 
Nodinee ese ee 3 8°93 38a iil 
VERVE RE em ee 12°84* 10°97 


The water was determined by direct weighing in a calcium 
chloride tube, the halogens being retained by an ignited mix- 
ture of lead oxide and lead chromate. 


* Determined in a separate sample. 


46 Wells, Wheeler and Penfild—Alhali-Metal 


The body is rapidly decomposed by exposure. It melts 
gradually between 70° and 90° and becomes white at about 
115°. It is decomposed by strong alcohol and by ether. 


LiCl. O10. 4H, 0. 


This was made by adding 60 g. of iodine to a hot saturated 
solution of 20 ¢. of lithium chloride in dilute hydrochloric acid, 
saturating with chlorine and cooling. A large quantity of 
long, yellow needles was thus obtained. On evaporating the 
mother-liquor in a desiccator larger prisms were deposited. 


Calculated for 


Analysis gave LiCl. Cisl. 4,0: 
Intimate ese DAF 2°16 2:01 
Chiovines=-ee es 39°96 39°94 40°80 
lodine- 242": 37°54 Soa 36°49 
WV GYRO go JLebL 20°93 Beas 20°68 


On exposure to the air the suostance quickly deliquesces, 
forming a yellow liquid. This gradually loses its color, finally 
leaving a solution of lithium chloride. The body melts at 
70°-80° and becomes white at about 180°. The crystals of 
this compound were not measured. 


Crystallography. 


The crystallization of CsI, is triclinic. By slow evaporation 
of a solution in a desiceator, crystals were obtained which were 
about 107” in diameter. Two crops were examined, in one of 
which the habit shown in fig. 1 prevailed while in the second 
the crystals were more highly modified like figs. 2 and 3. 


1. 2. 


3t 


a, 100, 7-7 oh Willer lar Oy Bilily 8 Bee 
c, 001, O ie OMe Ler ¢, 341, —4-¥” 
m,110, I Gy Oy 25 y, 341, 4-3” 
WEL), JE p, 311, —3-3’ 


The axial ratio is as follows: 
&:b:¢ = 0°9890:1 : 0:42765 
a = 96° 56’ f= 89° 553! y = 90° 21}' 


Pentahalides, with their Crystallography. 


47 


The erystals gave good reflections of the signal on the 


goniometer. 


were chosen as fundamental are indicated by an asterisk. 


Measured. Calculated. 


a@ x~¢, 100.001 =*90° 27 
maM, 110.110 =*89 47 
a am. 100.110 =*44 43 
Cc a é, 001.021 =A 26 
é ad, 021A 011 =*65 25 
an. 100,110= 45 4 
ti AG NODA OD ss 80 133 
a als LOOVNO MS 89 57 
a «xp, 100,311= 41 18 
i aA, NOOR BU 3 Ao besaiik 
A, 
TG 
hp nd 
yall eet 
IF) fi 
Brie, 
oa | | 
ale 
cae 
(210 & b, 010, 7 
| ’ 


Measured. Calculated. 
Lab, QO ACIS Sa0e woe 
Lap, 210.212 = #442 5]! 
DAs 2122 ly — 106535 
le tGby PO re ON SP ie} Fe fio 
ye 
monoclinic. 


b, 010, i-1 
COO O 


The axial ratio is as follows: 


45° 
90 
89 
41 
41 


) 


4’ 
16 
54 
19 
25 


UL @:b:¢ = 0°9423:1:0°4277 


In the following tables the measurements which 


Measured. Calculated, 


e am, 001.110 = 85° 
e ~M,001,110 = 85 
é nm, 021 4110 = 65 
en Me O20! 165 
dam, 0114110 =70 
dxM, 011,110 = 170 
pxm, 3114110 = 40 


fad, 041,011 = 32 
“am, 341.110 = 25 


The axial ratio is as follows: 


d, 


8” 85 
7 84 
9 65 
8 65 
3 70 
6 70 
41 40 
30 32 
46 25 
56 25 


q 


° 


9’ 
74 


18 


The form of CsCl. Cl,I is monoclinic. From a 
number of crystallizations this salt was always ob- 
tained in needles, sometimes over 20™™ in length 
_ and having the habit shown in fig. 4. 
| The forms which were observed are: 


1, 9/5' = 100/001) —=1862 20) 
Measured, Calculated. 
(es) NOs Olle= 2 Cae 287344 
DAD, Alar oilie—= en nog Be Y 
WA. BAZ OND == i Bl 329 
bAd; O10. 041 = 31 0 30. 21 


The crystallization of RbC1.CI,I is 


This salt was crystallized a 


great many times and was always ob- 
tained in plates, sometimes over 20™™ 
broad, but seldom 1™™ thick. The habit 
is shown in fig. 5. 

The forms which were observed are : 


m, 110, 


iE 111, 


fy MU al 


1 


25.6 = 1:1890:1:1:975, 6 = 100, 001 = 67° 63’ 


48 Wells, Wheeler and Penfield—Alkali-Metal 


Measured. Measured, Calculated, 
Cam, 001 . 110 = *74° 267 Gn 8, 00) AU 182-010 ep alog 
Cre 0100 lengli —a*501 320 SSO AU! a M0) SSR) 2X0) yey 1) 
IN elles el se — Ge ae nT, LO) a9 19 6 


With the polarizing microscope the plates show an extine- 
tion parallel to their diagonals. In convergent light nothing 
of the ring system can “be seen, but a dark bar crosses the 
field in the direction of the sy mmetry plane, indicating that 
the plane of the optical axes is the clino-pinacoid. 

The erystalline habits and axial ratios of CsCl. Cl,I and 
RbCl. Cl,I are wholly different and all attempts to find any 
similarity or mathematical relation between them has failed. 
We have endeavored to detect any hidden relation that might 
exist by examining separate crops of crystals, made from a 
solution containing both salts. Each form alone and mixtures 
of both were thus obtained, but no crystals of an intermediate 
form could be produced. One unmixed crop, having the form 
and angles of CsCl. Cl,I, contained about sixteen per cent of 
RbCl. Cl,I, while another, having the form and angles of 
RbCl. Cl,1, contained about eleven per cent of CsCl. Cl,I. 

6. These results show that isomorphous mixtures can 
be obtained of either form, depending upon which 
salt predominates, while the absence of any inter- 
I | mediate forms, and the inability to detect any mathe- 
(| matical relation between the two kinds of erystals, 
i | leads us to believe that the compounds are dimor- 
|| | |} phous. 
mei" The form of KCl. Cl,I is monoclinic. This salt 
was repeatedly made in tine needle-like crystals, too 
small to measure, by allowing a warm saturated solu: 
| || tion to crystallize. By slow. evaporation in a desic- 
Neb? cator, at ordinary temperatures, stouter prismatic 

crystals, over 20™™ long and 2™™ in diameter, were 
obtained having the habit shown in fig. 6. These gave excel- 
lent reflections and were measured without difficulty at winter 
temperature. 

The forms which were observed are 


a, 100, 7-7 n, 120, 7 
me LO. Ti d, 023, 3-% 
The axial ratio is as follows: 
@:6:€=0°9268:1: 044725, 8 = 100, 001 = 84° 18’ 
Measured. Measured. Calculated. 


mam, 110.110 = *85°-22/ — awd) 1100)x 023) = "8327 
did ei023%0023 — Sones nan, 120,120= 56 58 56° 567 


Pentahalides, with their Crystallography. 49 


The positions and crystal symbols which have been adopted 
for this and the corresponding cesium salt were chosen to 
show a similarity in the axial ratios. Both salts are alike in 
having a prismatic habit, but the forms which occur on each 
are quite different. If it were not for bringing out this simi- 
larity in axial ratios the crystallography of both salts could be 
simplified somewhat by giving to the dome d above the sim- 
pler indices 011 and by taking the prism and pyramids of the 
cesium salt as belonging to the unit instead of to the macro- 
diagonal series. 

The anhydrous alkali-metal pentahalides do not form a well- 
defined crystallographic series, yet there are relations between 
three of them which seem to us to be more than coincidences. 
The similarity is shown in the following table: 


CsCl. Cl,I Monoclinic a: 
KCl. Cl, Gi a: 


0°9423:1:0-4277, 6 = 86° 20’ 


c= 
C = 0:9268:1: 044725, 6 = 84° 18’ 


SI Sy] 


Qo! 


CsI 


5 


Triclinie } G:b:¢= 09890: 1: 0:42765 
a = 96° 56’, 6 = 89° 554’, 7 = 90° 214 


7. The erystallization of NaCl. Cl,I.2H,O is or- 
thorhombic. By slow evaporation of a solution 
\ In a desiccator crystals were formed over 10™™ in 
—*“ length, having the habit shown in fig. 7. 
The forms which were observed are: 


b, 010, 7-7 foe selves yal 
m, 110, J d, 021, 2-% 


The axial ratio is as follows: 
G:b:0 = 0°6745 :1:0°5263 


‘The crystals were measured at a temperature 
near 0° C. and gave excellent reflections. 


Measured. Measured. Calculated, 
TU a0; Op — 68am 0 m «0; WNOO1L0 = 56% 07 56° 07 
map, IOA111=*46 44 OPN Gis ONOVALO Ze — A 3552.9 43 32 


Sheffield Scientific School, 
April, 1892. 


Am. Jour. Sci.—THIRD SERIES, Vou. XLIV, No. 259.—Juny, 1892. 
4 


50 N. H. Darton—Fossils in the “Archean” 


Art. V.—Fossils in the “ Archean” rocks of Central Pied- 
mont Virginia; by N. H. Darron, U. 8. Geological 
Survey. 


Iv is my purpose in this paper to announce the discovery of 
organic remains of Lower Silurian age in the roofing slate at 
Arvon, Buckingham County, Virgittia. 

Piedmont Virginia received considerable study from W. 
B. Rogers in the State Surveys of 1835 to 1840, but I know 
of no ‘subsequent investigations of its structure. The region 
contains a great variety of rocks, comprising granites “and 
gneisses in large part, mica schists, chlorite schists, slates, mar- 
bles, conglomerates and various basic intrusives. The clastics 
are considerably metamorphosed and apparently their structure 
is complicated. 

During a recent reconnaissance of the Piedmont plain west 
of Richmond, in connection with studies of its geomorphology, 
I found myself near the slate quarries at Arvon, and on visit- 
ing them I discovered the organic remains. The locality is on 
a small branch of Slate River four miles southwest of Bremo 
Bluff Station on the James River, in the northeastern corner 
of Buckingham County. The belt is one of several which 
occur in Piedmont Vir ginia. The slate is hard and durable 
and it is extensively quarried for the market. W. B. Rogers 
refers to these slates in the part on Virginia in Macfarlane’s 
‘Geological Railway Guide and classifies them as Huronian, but 
on what grounds is not stated. I did not have time to study 
the local ‘weologic relations of the slates, but it was noticed that 
they lie in a closely folded syncline in an altered sandstone 
which is in turn underlain by a highly altered conglomerate. 
This conglomerate increases in mass southward and finally e o1VeS 
rise to Willis Mountain, an elevated knob which stands out 
piggy above the Piedmont plains. The cleavage of the 

slate dips 8. 70° HE. >85°. The slates are cut by dikes of dia- 
Ss | ( 

base which have caused some local shattering, and they also 
contain occasional knots of quartz in which Dr. “G. H. Williams 
recently discovered the mineral anatase.* 

The fossils occur in a narrow belt along which the bedding 
and cleavage coincide. This portion of the quarry is now in 
greater part buried under debris, but owing to the kindness of 
Mr. Williams, the superintendent, I was able to secure several 
slabs. “The remains are solely of crinoids and the slabs bear 
many fragments of various parts of these organisms. The 
accompanying figures represent the more characteristic forms, 
faithfully reproduced | by Mr. Hunter of the Geological Survey. 


* This Journal, III, vol. xlii, pp. 431, 432. 


Rocks of Central Piedmont Virginia. 51 


SS 
: 1 
| 


LY f 
PRE 
i 


7 iy 
“eff? 
We 
higgpe 77 


2 C. D. Walcott—Cambrian Rocks of 


Or 


The slabs were submitted to Mr. C. D. Walcott, who has 
kindly made the following statement regarding them: ‘I have 
studied the specimens of “slate show! ing crinoidal remains and 
come to the conclusion that they belong to the Trenton-Lor- 
raine or upper portion of the Ordovician fauna. One of the 
larger columns is closely allied to Schizocrinus nodosus, and 
some of the heads, although indistinct, approach closely to 
Heterocrinus and Poterocrinus. If these suggestions are cor- 
rect, the slates are to be correlated with the Lorraine or Hud- 
son series and in the same horizon with the Peach Bottom 
slates of Pennsylvania. 

The occurrence of fossiliferous beds in the crystalline area 
of Virginia will greatly aid in the determination of the age 
and structure of its rocks, and the discovery at Arvon may be 
regarded as a most fortunate one. There are several other 
belts of slate in the Piedmont region, notably in Virginia, 
Maryland and Pennsylvania, and it seems probable that “other 
similar localities may be discovered. I have recently explored 
one of these belts which comprises the easternmost rock outcrop 
along the edge of the coastal plain from north of Fredericks- 
burg to a short way beyond the Occoquan River, but without 
finding fossils. This belt will be designated the “ Quantico 
slates” on the ‘“ Fredericksburg” and ‘‘ Mount Vernon” sheets 
of the U.S. Geological Survey. Its slates are similar to those 
of Arvon, but somewhat more altered, and they were at one 
time worked to some extent for roofing slate, although most 
of the beds contain more or less pyrite which renders them 
unserviceable for roofing. 


Art. VI.—Wotes on the Cambrian Rocks of Virginia and 
the Southern Appalachians ; by Cuas. D. Waucort. 


In connection with the study of the Cambrian rocks and 
faunas of North America I made a hurried reconnaissance in 
the fall of 1891 of the sandstone series of central Virginia. 
In company with Mr. Bailey Willis and Prof. H. D. Campbell 
an examination was made of the Balcony Falls section along 
the line of the James River. It failed to bring to light any 
traces of organic remains other than the Scolithus that occurs 
in the massive quartzite below the ferriferous shale at the 
western end of the gorge. On the following day well pre- 
served specimens of a species of Ptychoparia were discovered 
in the shale, by the roadside, about a mile south of Natural 


Virginia and the Southern Appalachians. 58 


Bridge and one-fourth of a mile north of Gilmore, on the 
James River. Crossing the James to the south side and oppo- 
site Gilmore, in company with Mr. Willis, a search was made 
for fossils in the strata above the Scolithus quartzite of the 
Balcony Falls section. At a point on a small brook about 
three-fourths of a mile from the river a calcareous sandstone 
was found to contain the heads of a species of Olenellus, like 
Olenellus Thompsoni, also Hyolithes Americanus and H. com- 
MUNIS. 

The discovery of these two horizons indicates that the 2000 
feet of strata beneath the ferriferous shales of the Balcony 
Falls section are of Lower Cambrian age, and that the shales 
not far beneath the dolomitice limestones of the Natural Bridge 
section are also of Cambrian age. The study of the heads of 
Ptychoparia, found in the latter section, show them to be so 
closely related to species from the Middle Cambrian beds of 
Tennessee that it is impossible to correlate the shales with the 
Upper Cambrian zone. Neither is there sufficient evidence, 
owing to the great vertical range of the species of Ptycho- 
paria of this type, to correlate the shales with the Middle 
Cambrian of Tennessee ; at present we can only state that they 
are of Cambrian age, and that the Cambrian section includes 
the strata from the base of the dolomites, to the Archean 
rocks at the base of the Balcony Falls section. It is not im- 
probable that some of the lower portion of the upper massive 
dolomites may be of Cambrian age. 

The Doe River and Nolichucky sections of northeastern 
Tennessee were next examined. Although no fossils were 
found in the lower quartzites and argillites, it is evident that 
these sections may be correlated with the Balcony Falls sec- 
tion of Virginia. In the Doe River section there is a Sco- 
lithus sandstone that occurs two thousand feet or more above 
the base of the section, and the superjacent series of calcareous 
and shaly beds are usually removed by erosion. The Noli- 
chucky section appears to be a greater development of the 
same series as that exposed in the Doe River gorge. 

In central Tennessee we were joined by Mr. M. R. Campbell 
and a large collection of Cambrian fossils was made in the 
vicinity of Rogersville, Tennessee, and many points relating 
to the stratigraphy of the Cambrian rocks of that region were 
determined by the finding of typical Cambrian fossils. 

West of Cleveland, in East Tennessee, the Olenellus or 
Lower Cambrian fauna was found near the base of the Knox 
sandstone of Safford or the Rome sandstone of Hayes. Be- 
neath the sandstone a considerable thickness of limestone 
occurs and subjacent to this 2000 feet or more of arenaceous 
and argillaceous shales in which the Olenellus fauna was 


54 C.D. Walcott—Cambrian Locks of 


found. In the central portion of the Rome sandstone series 
of the Cleveland section, 100 to 200 feet above the Olenellus 
fauna, a few species of the Middle Cambrian fauna were found, 
and higher up, in the shales and limestones above the sand- 
stone, an abundant fauna that is now referred to the Middle 
Cambrian zone. The same succession of faunas was found in 
the section east from Post Oak Springs, Roane County, Ten. 
nessee. The Middle Cambrian fauna of the sandstone and 
also of the superjacent shales was found in the section ten 
miles east of Knoxville at Shook’s gap through Bay’s Mountain 
where the section is similar to that west of Cleveland. The 
same sequence of Middle Cambrian faunas was found in the 
Knox sandstone and the superjacent shales immediately north 
of Knoxville. Types of this fauna also occur in the Rome 
sandstone series at Rome, Georgia, and in the limestones and 
shales of the Coosa series, in Coosa Valley, north and south of 
Cedar Bluff, Alabama. 

After returning from the field and when studying the faunas 
from the Tennessee and Coosa Valley sections, great doubt 
arose as to the correctness of placing the Coosa shales beneath 
the Rome sandstone in the stratigraphic section.* 

Dr. Cooper Curtice who had studied the formations of the 
Coosa Valley, when collecting for the U. 8. Geological Sur- 
vey in 1885, was instructed to re-examine the sections of the 
Coosa Valley and those to the south, in Alabama. This expe- 
dition resulted in the discovery of ‘the Olenellus fauna in the 
shale in the vicinity of Montevallo, Alabama, and in obtaining 
evidence showing that the greater portion of the Coosa shales 
and limestones of the Coosa V alley were above the Rome 
sandstone series. 

The data obtained during the field season enable me to cor- 
relate and bring into their proper stratigraphic position the 
collections that have been made by geologists and for the U.S. 
Geological Survey from the Cambrian rocks of the Southern 
Appalachians, and to establish the fact that during Middle 
Cambrian time there was a great deposition of sediments that 
now form a series of shales and limestones nearly 3,000 feet in 
thickness. The Lower Cambrian is represented by the lower 
portions of the Rome sandstone, the limestone immediately 
subjacent and the series of variegated arenaceous and argilla- 
ceous shales forming the base of the series. . A study of the 
fauna shows that the typical Upper Cambrian fauna of the 
Adirondack region of New York and the upper Mississippi 
Valley area of Wisconsin and Minnesota, has not yet been 

*The Overthrust Faults of the Southern Appalachians. Bull. Geol. Soe. 


America, vol. ii, February, 1891, p. 143, pl. 3; also, Bull..U. 8. Geol. Survey, No. 
81, 1891, p. 304. 


Or 


Virginia and the Southern Appalachians. 5 


found in the Appalachian region south of New York. In the 
central eastern Tennessee section the upper limit of the Mid- 
dle Cambrian fauna is in a shaly band, not fifty feet below the 
cherty beds of the Knox dolomites which usually have been 
referred to the Lower Silurian (Ordovician). The recent dis- 
covery by Mr. M. R. Campbell of the typical Calciferous fauna 
of the New York section at an horizon 2000 feet up from the 
base of the dolomites negatives this reference and indicates 
that the Upper Cambrian in Tennessee is represented by the 
lower 2000 feet of the Knox dolomites in the southern por- 
tion of the Appalachian trough. In the vicinity of Rutland, 
Vermont, the upper portion of the Lower Cambrian and all of 
the Middle and Upper Cambrian, if present, are included in 
the dolomites and marbles above the “ granular quartzite ” and 
it is probable that the lower portion of the great limestone 
belt of Pennsylvania and Virginia is of Cambrian age. 

The sediments of the massive quartzites of the Lower Cam- 
brian that extend from Northern Vermont to Alabama, along 
the line of the eastern margin of the Cambrian paleo- Appa: 
lachian sea were evidently accumulated near the shore. At 
Balcony Falls, Virginia and Chilhowee Mountain,* Tennessee, 
the Olenellus fauna oceurs in connection with the series, and 
it appears to be a fair inference that while the sandstones of 
Chilhowee, ete., were being deposited in the vicinity of the 
shore line the variegated shales and limestones of the Lower 
Cambrian were being deposited farther off shore in the sea to 
the west. This sea was shallow and from the distribution of 
the Rome sandstone series the inference is that much of the 
sediment was derived from the west. The close of the epoch 
in which the coarse sand was deposited along the Virginia 
portion of the shore was abrupt and the immediately super- 
jacent deposits indicate a deepening of the sea. The Rome 
sandstone epoch was of relatively short duration although of 
wide geographic distribution in eastern Tennessee and northern 
Georgia and Alabama. 

The conditions which resulted in the deposition of the 
Knox dolomites during Upper Cambrian time in the southern 
portion of the Appalachian trongh were probably connected 
with the orographic movement that gave rise to the more strik- 
ing phenomena in the northern portion of the Appalachian 
trough, and affected the deposition of the sediments over the 
interior of the continent. 

In the valley of the St. Lawrence, especially at Point Levis, 
opposite Quebec, a bed of conglomerate occurs on the south 
shore of the St. Lawrence below Point Levis and also on the 
south shore of the Island of Orleans. This conglomerate 


* Bull. U. S. Geol. Survey, No. 81, 1891, p. 302. 


6 C.D. Walcott—Cambrian Rocks. 


Or 


includes bowlders of limestone carrying the Lower Cambrian 
fauna. It is from 1,500 to 2,000 feet below the conglomerate 
beds of Point Levis, which carry, in the lower beds, large 
bowlders of limestone in which the Middle and Upper Cam- 
brian faunas occur. By the fossils contained in the matrix of 
the upper conglomerate series it is known that it is of Lower 
Ordovician age, and from this it is inferred that the lower 
conglomerate, carrying the Lower Cambrian fauna, occurs in 
strata corresponding to the Upper Cambrian zone. The pres- 
ence of these bowlder conglomerates of Upper Cambrian and 
Lower Ordovician age proves that an orographic movement 
occurred in the valley of the St. Lawrence by which the 
Lower Cambrian and later Cambrian limestones were elevated 
and formed a portion of the shore line during Middle, late 
Cambrian and early Ordovician times. 

From my recent studies of the Cambrian rocks and faunas 
over the interior of the continent, I conclude that the conti- 
nent was depressed during the latter part of Middle Cambrian 
and the early part of Upper Cambrian times, so that the sea 
transgressed across the great interior of the continent and 
deposited the sediments of the interior continental province. 

From the preceding statements it appears that toward the 
close of Middle Cambrian time and during Upper Cambrian 
time there was a decided continental movement, resulting in 
the depression of the interior continental plateau, and that 
this was accompanied by the formation of conglomerates of 
the older Cambrian rocks in the valley of the St. Lawrence 
and by a great deposition of sediments of later Cambrian 
time in the Southern Appalachian region. In a paper soon to 
be published by Mr. Arthur Keith of the U.S. Geological 
Survey evidence will be presented of an orographic movement 
in Eastern Tennessee during this period. 

The fauna of later Middle Cambrian time, in Tennessee, 
Georgia and Alabama, is essentially the same as that of the 
basal Cambrian deposits about the Adirondack Mountains, the 
upper Mississippi Valley areas of Wisconsin and Minnesota, 
those about the Black Hills of Dakota, and the Llano Hills of 
Texas. 

The fauna of the lowest horizon in Wisconsin includes Hyo- 
lithes primordialis, Ptychoparia calymenoides, Agraulos (2) 
Secundus, Crepicephalus onustus, and Agraulos Wooster. In 
the next zone above, which is also included in the Middle 
Cambrian, the following species oceur: Linguiaampla, Lingu- 
lepis pinnaformis, Obolella polita, Hyolithes primordialis, 
Pemphigaspis bullata, Agnostus sp., Crepicephalus Texanus, 
C. Lowensis, Ptychoparia connata, P. optatus, P. (Loncho- 


C. Ludeking—Synthesis of Crocotte and Phenicochroite. 57 


cephalus) Chippewensis = P.(L.) minor, Amphion matutina, 
and Agraulos thea. 

The line of demarcation between the Upper and Middle 
Cambrian in Wisconsin is drawn between the beds carrying 
the. preceding fauna and the superjacent strata. These two 
horizons also occur in the Potsdam sandstone about the Adi- 
rondack Mountains and in the Cambrian section of the Llano 
Hills of Texas. 

Tt was not until after the recent work in the Cambrian of 
Tennessee, Alabama and Georgia and an extended comparison 
of the faunas with those of the Upper Mississippi Valley was 
made, that the line of demarcation between the Middle Cam- 
brian and Upper Cambrian was drawn. The reasons for this 
will be more fully presented in a memoir now being prepared 
upon the Middle Cambrian rocks and faunas. 

In this preliminary study I had the use of the unpublished 
geologic maps of eastern Tennessee that have been prepared 
by the Appalachian Division of the Geological Survey, and 
Mr. Bailey Willis gave me great assistance by placing at my 
service his extensive knowledge of the country and its geol- 
ogy. It is anticipated that the work on the Cambrian rocks 
and fossils will be continued in the Appalachians during the 
field season of 1892. 


Art. VII.—Synthesis of the minerals Crocoite and Phe- 
nicochroite ; by C. LuDEKING, Ph.D. 


THE synthesis of Crocoite and Pheenicochroite may be accom- 
plished by exposing for several months to the air a solution of 
lead chromate in caustic potash in a flat dish or plate. It is 
possible thus to obtain a mixture of the crystals of the two. 
Without any difficulty whatever the individual crystals can be 
picked out separately by means of a pincette and obtained in a 
state for analysis. 

The following are the analytical results obtained : 


Found, Calculated. 
Crocoite. Bbaw63.9 64:04 + 
CrO 5:2 35°96 — 

99°1 100°00 
Found. Calculated. 
Phenicochroite. Pb 71:2 71°43 — 
CrO, 25°9 26°73 + 


It appears therefore from this showing that the chemical 
composition of the artificial crystals approximates quite closely 


58 ©. Ludeking—Synthesis of Crocoite and Phenicochrotte. 


to the. calculated values. Rather strong solutions of caustic 
potash should be used and much precipitated lead chromate 
dissolved. 

The crystals obtained are rather small, but can readily be 
studied by means of a lens, or better, a microscope. They 
show many modifications of the primitive form, as do also the. 
natural crystals. 

I was able to obtain by the same method: crystals of (2PbO) 
(1,0), by exposing to the air for several months a saturated 
solution of litharge in caustic potash.* 

It was intended to produce by this means cerussite. The re- 
action is of course quite clear. The carbon dioxide of the air 
acting upon the alkali converts it into carbonate which is not 
a solvent for PbO. Consequently this latter very slowly sep- 
arates out as a crystalline hydrate, being slightly soluble itself, 
a necessary condition for crystallization. 

So likewise the solution of PbCrO, in KOH on exposure to 
the air yielded crystals of crocoite and of phcenicochroite. 
The formation of the former is due simply to the slow abstrac- 
tion of the solvent by the carbon dioxide of the air. The 
formation of the latter, the phcenicochroite, is on the contrary 
effected by another reaction, a portion of the chromic acid 
being appropriated by the KOH. The lead being thus de- 
prived of the normal quantity of chromic acid, a basic com- 
pound, pheenicochroite, is formed. 

On reflection it seemed that it might be possible to obtain 
each of these minerals alone instead of in mixture as above. 

By using a large excess of very strong solution of KOH, 
phoenicochroite only was formed, or rather only very little 
crocoite. When on the contrary much PbCrO, is dissolved 
and in addition K,CrO, is added to the KOH solution, crocoite 
alone is formed. I need not enter upon an explanation of 
these phenomena as they are almost self-evident. I shall now 
briefly describe the minerals obtained. 

The PbCrO, crystals are oblique rhombic prisms with raany 
modifications. The fracture is uncertain; luster adamantine ; 
color hyacinth-red. They are stable in the air. The pheenico- 
chroite crystals are tabular, of resinous luster, of cochineal 
color and appear to be orthorhombic. They, like the natural 
crystals have but little stability and soon change to a light yel- 
low powder on exposure. 

At Beresowsk, crocoite and phceenicochroite are associated. 
It is not impossible that they were formed also by the action 
of the carbon dioxide of the air upon an alkaline solution of 
PbCrO,, as in my first experiment. 


* Amer. Chem. Journ., vol. xiii, p. 120. 


w 


R. S. Tarr—Origin of Terraces in Glaciated Regions. 59 


Art. VIIL—A int with respect to the Origin of Terraces 
in Glaciated Regions; by RaupH 8. Tarr. 


THE exact method of formation of terraces in rivers flooded 
by the melting of the ice sheet, such rivers for instance as the 
Connecticut, does not appear to be definitely agreed upon by 
geologists. By some they are supposed to mark recent erosion 
in a drift-filled valley. That is, the supposition is that the 
glacially fed rivers were overloaded and actually built up their 
beds to the height of the higher terraces, and in this exten- 
sive deposit the present terraced vailey has been carved. The 
other important theory is that the terraces mark high stages of . 
floods—that they are flood plains at various stages of flooding. 

It is not.my purpose to enter into the subject in a critical 
manner and state the reasons pro and con which have been 
advanced by the advocates of these theories, but, rather, to 
record some observations in an entirely different region where 
the terraces of glaciated regions are being imitated, and where 
the general conditions are quite similar to those attending the 
formation of the terraces in glacial regions, as I understand 
those conditions. I refer to the valley of the Colorado in 
Central Texas. 

The river is here superimposed upon a hard Silurian barrier 
which is effectually retarding its downcutting although the 
river is still well above base level. One of the effects of this 
retardation of development on the region upstream from the 
barrier is that a temporary base level is produced and the Colo- 
rado itself and the side stream are for a certain distance actu- 
ally building up their beds. The effect of the barrier is thus 
felt for forty or fifty miles; but above this, the flow is rapid 
and the river is degrading its channel. Along the entire 
course the side streams are rapidly at work, and from these 
two sources much sediment is being furnished. Owing to the 
many soft beds of Cretaceous, Permian and Carboniferous 
through which these streams are flowing the amount of sedi- 
ment supply is very great. 

Another point of importance in this connection is the pecu- 
liarity of rainfall. The immediate region is sub-humid, the 
extreme head waters are in a truly arid region. Consequently, 
the water supply, during a great part of the year, is small in 
amount; but heavy rains, which are of annual occurrence, 
and often of greater frequency, bring to the river vast floods 
of water which the ordinary channel is totally unable to hold. 
Almost the entire rainfall has to be carried off ; for the barren 
soil holds but little, and the violence of the rain speedily forms 


60 R. S. Tarr—Origin of Terraces in Glaciated Regions. 


it into rills and rivulets even where no drainage lines previ- 
ously existed. While this is written chiefly with reference to 
the arid headwaters it applies almost equally to all the streams, 
even those in the sub-humid belt. These tributaries during 
the greater part of the year consist of a few pools, often iso- 
lated, sometimes connected by a slowly trickling stream. These 
pools are enclosed commonly in bars or delta bars in the stream 
channel, formed during flood times, and the violence of these 
floods is attested by the presence of drift wood lodged in 
the pecan trees many feet above the low water stage of the 
stream. In the Colorado these are sometimes at an elevation 
of fifty feet above the low water surface. 

If I am not mistaken, we have here all the essential condi- 
tions which were present at the time of the formation of the 
terrace deposits at the close of the Glacial period. There isa 
slope so moderate that the excessive sediment load cannot be 
transported, and the greatest excess of sediment comes at times 
of great flood, for the sudden downpour of water upon the arid 
plains carries along to the streams a vast bulk of sediment. 
There are, owing to the peculiarities of rainfall, periods of 
extreme high water and of extreme low water, and also occa- 
sional irregular periods of moderate rise. In the glacial 
regions the south-flowing stream had a moderate slope, proba- 
bly less slope than at present. Vast quantities of sediment 
were furnished not alone by the supply from the ice itself but 
also from the beating of the rains and the washing action of 
the melting snows upon the barren soil recently uncovered 
from beneath the ice and as yet unclothed by vegetation. In 
the summer, excessive floods must have been furnished by the 
welting of the ice; in the winter the water flow was at a 
minimum; and in the spring and autumn, when the melting 
was moderate and somewhat spasmodie, floods of medium 
height occurred. 

The parallel of conditions seems almost exact; let us see how 
the results coincide. In the Colorado the great floods rise 
forty and fifty feet and spread out over broad flood- -plains on 
either side, and these flood plains are of fine silt, well strati- 
fied. This is the upper flood-plain terrace. In this flood- 
plain a broad channel is carved, which, in moderate floods, is 
either partly or completely filled by the water. It is however 
a double channel, for in it, either on one side or on the other, 
or even in the middle, there is a smaller channel about half its 
width and this is the ordinary channel,—the one in which 

water is always to be found. So, rising from this inner chan- 
nel, one comes to a terrace which is formed by the moderate 
floods and which is always present on one side, sometimes on 
both. It is in general more sandy than the other or upper 


R.S. Tarr—Origin of Terraces in Glaciated Legions. 61 


terrace first mentioned, which is reached by a steep ascent of 
fifteen or twenty feet. 

Nor are these two terraces the only ones. Above the upper 
flood plain terrace is a third or still higher one which is much 
less distinct and more irregular and coarser in composition. It 
is formed by the wash of material from the bordering hill-side 
and the detritus brought in by the side streams. This, in the 
ease of exceptionally high floods, is partly worked over so as 
to form an indistinct upper terrace. 

IT ask any student of the subject if this is not a description 
which would apply almost equally well to terraces in glacial 
regions. As I know the terraces of the Connecticut, there are 
one or two lower terraces sometimes present on one, sometimes 
on both sides of the river. Above these is a higher, broader, 
flood plain terrace, often of great breadth, and frequently ex- 
tending over low divides,—just such a terrace as would be 
expected from a great flood which the ordinary river was 
absolutely unable to take care of. Still above this is an upper 
terrace, irregular in distribution, and in form, often of a coarse 
nature, and particularly so below the mouths of side streams 
where it is delta-like in form. This is a terrace comparable, on 
a larger and more perfectly developed scale, with the upper- 
most terrace of similar origin in the Colorado. 

When I saw the terraces of the Colorado two years ago I 
was immediately impressed with the resemblance to the terraces 
of the Connecticut both in form and in cause, the difference 
being only in the source of the floods. Later I have examined 
the Connecticut terraces in Massachusetts with this resemblance 
in mind and it is so striking that I desire to put it on record, 
and to call attention to the fact that terraces are being formed 
on asmaller though not by any means an insignificant scale, 
which imitate the terraces of glacial regions in form and in 
general cause. In the one case the floods and sediment supply 
arise chiefly from the climatic accident of desiccation, while in 
the other they are the result of glacial accident. Otherwise 
the resemblance seems to be quite perfect. 


62 £. Orton— Occurrence of a Quartz Bowlder 


Art. [X.—On the Occurrence of a Quartz Bowlder in the 
Sharon Coal of Northeastern Ohio ; by EDWARD ORTON. 


Ir is well known that bowlders, ranging in size from a few 


cubic inches to several cubic feet, are occasionally met with in 
coal seams, buried partially or entirely i in the substance of the 
coal. Facts of this sort have been reported both in this country 
and in England. The State of Ohio has furnished the largest 
number, if not all, of the cases reported in this country. In 
England, Mark Stirrup, Ksq., Hon. Secretary of the Moncuetes 
Geological Society, has reported in the Transactions of this 
Society a number of such occurrences, all derived from mines 
in the neighborhood of Manchester. 

The Ohio examples that have been hitherto put on record 
are without exception, so far as my observation goes, composed 
of gray quartzite, presenting the appearance of pretty thor- 
oughly metamorphosed sandstones. By correspondence and 
comparison of specimens with Mr. Stirrup, I learn that the 
English bowlders of the coal agree very closely with ours in 
composition and general character. 

All of these bowlders are well rounded and some that I have 
seen show remarkably smooth surfaces which suggest the pol- 
ish due to glacier action rather than the abrading agency of 
water in motion. They are always partially covered with 
closely adhering coal, which shows more or less of the striated 
structure known as slickensides. 

The Ohio bowlders have all been derived from a single coal 
seam, viz: the Middle Kittanning seam of our scale, and thus 
far, only from the western boundary of this seam, in Perry and 
Vinton’ counties. Furthermore, a single mine in the last 
named county, viz: the main mine at Zaleski, has furnished 
thus far all the specimens. According to the testimony of the 
superintendent and miners, scores of these bowlders have 
sometimes been found in working outa single room. The 
first example in Ohio was recorded by the late Prof. E. B. 
Andrews (Geol, Survey of Ohio, Rept. of Progress, 1870, p. 
78.) This bowlder came from the mine named above. 

By far the largest of this class of bowlders thus far known 
was found buried in the coal of the same seams at Shawnee, 
Perry Co., in 1876. The seam was normal above it and also 
below. The weight of this bowlder is not less than 400. lbs. 
It is preserved in the geological museum of the State Uni- 
versity at Columbus. 

A new example of these bowlders of the coal has lately been 
brought to light that differs so much from the examples pre- 


| 
; 
‘ 


in the Sharon Coal of Northeastern Ohvo. 63 


viously even ed that it deserves brief mention. It was found 
in the Marshall Mine of Mineral Ridge, Mahoning county, by 
Mr. F. C. Goff, of Cleveland, who is extensively engaged in 
mining and shipping coal, and it was removed from its bed by 
his own hands. The thickness of the coal seam is three feet 
and the bowlder lay two feet below the top. The seam was 
in no wise disturbed in its structure by the presence of the 
bowlder. The weight of the block in its present condition, 
after the removal of a few small fragments, is 10 lbs. 10 oz. 
Tt measures about eight inches in its longest dimension. The 
coal is very closely welded to it over part of its surface and it 
shows the usual slickensided appearance. 

The noteworthy points in regard to this bowlder are the 
following, viz: (1) It is the first so far as I know that has 
been reported from this coal seam, viz: the Sharon Seam or 
the lowest coal of the Conglomerate Coal Measures of Pennsyl- 
vania and Ohio. (2) It is not a metamorphic sandstone or 
quartzite, like those previously named, but is an excellent ex- 
ample of vein quartz. (8) It has not been worn or shaped in. 
any way by either water or glacial action, but is angular as if 
freshly broken from the parent mass. 

No full and satisfactory explanation of this line of facts has 
yet been advanced. The quartzite above named could perhaps 
be accounted for without referring them in origin to the meta- 
morphic rocks of the older regions of the continent. May not 
an ordinary sandstone pebble or bowlder of the Coal Measures 
have been converted into a quartzite by the solution of a por- 
tion of its silica through the agency of the organic acids that 
accompanied the formation of coal. But like the white quartz 
pebbles of the great Sharon Conglomerate that underlies this 
coal seam, the bowlder here described must be referred to the 
ledges of the eastern or northern mountain borders of: the 
continent as it then existed. The pebbles of the conglomer- 
ate never exceed a few ounces in weight and their rounded 
forms and smooth surfaces bear witness to an immense amount 
of abrasion before they reached their present resting places; 
but the bowlder in question, with its weight of 11 lbs. and its 
sharp and unworn edges and with its anomalous location, cer- 
tainly shows a very different history. 


Columbus, Ohio, May 13th, 1892. 


64 J. Whitmore—Method of Increasing 


Art. X.—A Method of Increasing the Range of the Capil- 
lary Electrometer; by JoHN WHITMORE. 


[Contributions from the Sloane Physical Laboratory of Yale College. ] 


THE value of the capillary electrometer as an instrument of 
scientific research is now generally recognized, and its applica- 
tions are becoming more numerous, both as an extremely deli- 
cate test for small electromotive forces and also, as recently 
pointed out by Burch,* as a means of studying variations of 
differences of potential. In view of these facts it is desirable 
that the range of this instrument be increased. 

The characteristic curve of Lippmann’s electrometer is 
slightly different from a straight line for electromotive forces 
from 0:00 to 0:45 volt, and consequently the instrument is 
most applicable to the measurement of potential-differences 
not exceeding 0°50 volt, although the direct measurements may 
be carried to about 1:00 volt, since 1:20 volts are required to 
produce continuous electrolysis in the instrument. The follow- 
ing experiments were undertaken in order to determine, if the 
range of the electrometer could be increased by arranging cells 
in series. 

If a capillary tube is filled with alternate globules of mereury 
and dilute sulphuric acid, the difference of potential which can 
be maintained between the extremities of the series increases 
proportionally with the number of globules of mercury. Thus 
with three globules, this difference of potential is about three 
volts. Ifthe terminals of the apparatus are connected with 
the poles of a battery, the globules immediately begin to move 
alone the tube, and the motion continues until the opposing 
force produced by the polarization of the globules of mercury 
causes the electric current to cease. The extent of the move- 
ment of the globules increases with the electromotive force. 

Since the end of each of the globules nearer the negative 
pole of the system, receives oxygen polarization and the other 
hydrogen polarization, one surface of the mercury is speedily 
oxidized. Such an oxidation causes the movement of the 
globules to become irregular, and prevents an accurate measure- 
ment of electromotive force. In Lippmann’s electrometer, the 
surface of the mercury, which receives oxygen polarization, is 
about ten thousand times greater than that upon which hydro- 
gen is accumulated, and by this means the surface density of 
the oxygen is diminished in the same ratio, and hence also the 
oxidation is decreased. 

In order, therefore, to obtain a similar Felton between the 


* Proc. Roy. Soc. of London, vol. xlviii, p. 89. 


the Range of the Capillary Electrometer. 65 


surfaces of the mercury, thistle tubes of the following descrip- 
tion were prepared. The larger part, by the head of the thistle, 
had a diameter of about two centimeters, while the stem had 
a capillary bore of 0°6 millimeter. The tubes were so bent, 
that each was U-shaped. The lower portion of the tubes was 
filled with pure mercury, and the upper part with dilute sul- 
phuric acid. The electric connections were so made, that the 
larger surfaces of the mercury received oxygen polarization. 

By reason of the described arrangement, a difference of 
potential between the terminals of a cell causes the mercury 
column in the vertical portion of the capillary tube to descend, 
and this depression is easily measured. Hence cells thus con- 
structed may be used singly as electrometers; and when joined 
in series, they form a convenient apparatus for the proposed 
investigation. 

As a means of obtaining any desired fraction of the electro- 
motive force of a Daniell cell, a standard box of high resist- 
ances and a few Daniell cells were arranged in series. Then 
the terminals of the electrometer were connected by movable 
contact pieces to the resistance box so that, as different resist- 
ances were inserted between the contact pieces, the electro- 
motive force to which the electrometer was subjected was pro- 
portionally varied. During the course of the investigation, 
curves showing the relation between the deflection and the 
electromotive force were carefully drawn. 

When two electrometer-cells of the form already described, 
were placed in series, the curve deviated but slightly from a 
straight line for electromotive forces from 0:0 to 0:9 volt. 
However as the electromotive force is made to exceed this, the 
deflections increase more slowly, and the entire curve when plot- 
ted was found to be of the well known form described by Lipp- 
mann. It is to be noted, however, if curves be drawn for a 
single cell and for two cells in series, that although the curves 
have the same form, the electromotive forces correspond- 
ing to any portion of the second curve are twice as great as 
those of the similar portion of the first curve. With three 
cells in series, the curve did not depart greatly from a straight 
line, until the difference of potential was about 1°35 volts, then 
the curve rapidly flattened and reached its maximum at about 
2°7 volts. 

These experiments show that the electromotive force is cut 
down by each additional cell, and hence that a series-electrom- 
eter may be thus constructed, which will conveniently meas- 
ure the electromotive force of the single cells ordinarily used 
in the laboratory. 

In order to discover how the total electromotive force, to 
which the electrometer is subjected, divides itself among the 


Am. Jour. Sc1.—TuHiIrD SERIES, VoL. XLIV, No. 260.—Juty, 1892. 
5 


66 J. Whitmore—Method of Increasing 
several cells, the difference of potential at the terminals of 
each of the three cells of a series was measured by means of 
Thomson’s quadrant electrometer. It was thus observed that 
the potential fell regularly along the series for the lower elec- 
tromotive forces. For example, when the total difference of 
potential was 0-9 volt, at the terminals of the first cell it was 0°3, 
and between the first and second 06 volt. The distribution of 
the potential among the different cells was less uniform after 
a total electromotive force of 1:2 volts was exceeded. This 
was possibly due to electrolytic conduction which occurred in 
the apparatus. Moreover the caliber of each of the capillary 
tubes was not exactly uniform throughout the entire length of 
the tube. Thus, these measurements clearly indicate, that 
with precisely similar cells, the fall of potential in each cell of 
the series is the same. 

It was next sought to put the apparatus in a convenient 
form. Since it seemed desirable to dispense with the use of 
the cathetometer in reading the deflections of the mereury 
columns in order that the reading might be obtained more 
quickly, experiments were made with cells in which a small 
electromotive force produced a large deflection of the mereury 
columns. This is notably the case in the electrometer used by 
Pratt,* in which the capillary tube is placed nearly horizontal 
and its inclination, and henee also the sensitiveness of the 
instrument, can be varied at will. Thus the mercury column 
can be caused to move over a space of a centimeter for a dif- 
ference of potential of 0-1 volt, and hence a deflection corre- 
sponding to a thousandth of a volt can be easily read directly 
on a scale placed behind the moving column. 

Accordingly three cells of this form were joined in series 
and a difference of potential was maintained between the ter-- 
minals of the series. It was found, however, that very often, 
when the electromotive force was applied, the mercury col- 
umns of the three cells, instead of moving together in one 
direction until the positions of equilibrium were reached, began 
a remarkable seesawing, the mercury column of one cell ad- 
vancing while those of the other cells retreated. This balane- 
ing continued through a considerable interval of time, since, 
as the positions of equilibrium were approached the vibrations 
were very slow. Moreover a given electromotive force at 
different times caused the mercury columns of the several cells 
to arrange themselves differently, so that no measurement of 
electromotive force could be made by observing a single cell 
of the series. However, when simultaneous readings of the 
three cells were made, and the curves drawn, though these 
curves were irregular in form, yet the mean of the three curves 
was of the normal type. 


* This Journal, vol. xxxy, 1889. 


the Range of the Capillary Electrometer. 67 


It was learned by means of a series of experiments that 
this irregular movement was in great measure caused by a dif- 
ference in the capacity and sensitiveness of the different cells. 
For when cells of the same capacity were adjusted to the same 
sensitiveness and joined in series, the columns moved together 
without seesawing. The difficulty of preparing cells of pre- 
cisely the same capacity and of adjusting them to the same 
sensitiveness is a serious objection to the employment of cells 
of this kind. Hence the electrometer composed of cells in 
which the movement of the mercury columns takes place in a 
vertical tube seemed on the whole more advantageous. 

Several different forms were tried. One arrangement con- 
sisted of three conical tubes each drawn to a very fine bore. 
These were placed one above the other the capillary stem of 
each containing mercury and dipping into the acid of the next 
lower cell. The electrometer in this form is somewhat diffi- 
cult to fill, and its action uncertain, owing to the formation 
of bubbles of gas in the capillary tubes. 

To cause the movement of the mercury in all the cells to be 
simultaneous, and of the same extent, as well as to secure 
compactness and better insulation. the form, represented in 
fig. 1, was finally adopted. 

A series of bulbs was blown, spaced at equal intervals along 
a capillary tube, the diameter of the bulbs being two centime- 
ters, that of the tube 0°6 of 
a millimeter. Then the 
tube was so bent, that the 
whole contained as many U- 
shaped parts as there were 
cells. One arm of each U 
was provided with a bulb 
which was situated at a dis- 
tance of two-thirds the 
height of the U from the 
base. The apparatus was 
easily filled by connecting it with an aspirator and drawing 
in sufficient pure mercury to half fill each bulb. Then by the 
same means dilute sulphuric acid was added until the capillary 
tubes and the upper portion of the bulbs were filled and all air 
bubbles excluded. Previous to the filling of the instrument, a 
solution of pure sulphuric acid and distilled water, consisting of 
four volumes of water to one of acid, was prepared, and allowed 
to stand until all the bubbles of gas formed by the mixture had 
disappeared. This was afterwards diluted, if necessary, with 
distilled water to the proper proportion. 

The operation of filling the electrometer was greatly facili- 
tated by having the tube which entered the upper part of the 
last bulb of the series of much greater caliber than that of the 


68 J. Whitmore—Method of Increasing 


others. In the instrument which was used, this tube had a 
diameter of about a centimeter, and its extremity was curved 
so that the terminal portion was at right angles to the vertical 
portion. Platinum wires were used as electrodes in the usual 
manner. 

As Lippmann has noted, the electrometer acquires a charge 
during the operation of filling, and therefore the instrument 
should be short-circuited for an hour or more before using so 
that the charge may be wholly dissipated, and the mercury col- 
umns stand at their true zero position. After the instrument 
had been filled in the manner above described, it was firmly 
mounted and placed on a pier before the cathetometer. Then 
the curve showing the relation between the deflections was 
constructed. Thus the deflections of the mercury column for 
electromotive forces varying from zero to that of three Daniell 
cells were observed on the cathetometer scale in hundredths of 
a millimeter, the readings being taken for electromotive forces 
differing from each other by 0:1 of that of a Daniell cell. 

From this curve the absolute value of the electromotive 
force corresponding to any deflection can be determined by 
taking the deflection produced by a standard Olark cell as a 
means of comparison. For example, it was found that the 
electromotive force of the Clark standard was 1°360 times 
that of a Daniell cell, and hence the electromotive force of 
the Daniell cell was 1:051 volts. Accordingly, when the 
curve, or empirical graduation of the instrument has been 
made, the voltage of other cells can be obtained immediately 
and with great facility. The curve gives directly the value of 
the cell in terms of the Daniell cell, and hence as shown above, 
the absolute value of the Daniell cell having been determined, 
that of the cell which was to be measured, is calculated by 
simple proportion. 

It is noteworthy, that not only is this electrometer valuable 
as a means of quickly comparing low electromotive forces, but 
that a high degree of accuracy is attainable in this comparison. 
Thus a number of cells, which had been standing in the labo- 
ratory were measured with the capillary electrometer and 
immediately afterward the absolute values found by the com- 
pensation method. 
This method of meas- 
urement is shown in the 
annexed diagram, fig. 2. 
Thomson’s electric bal- 
ance gave the value of 
the strength of current. 

The following table 
exhibits the results of G, Galvanometer. R, R, Resistance Boxes. 
the measurements. C, Cell tested. K, Key. 


2. 


the Lange of the Capillary Hlectrometer. 69 


Thomson's Balance Capillary 
Cell. Method. electrometer. 
Silver Chloride ..-.- 1°020 volts. 1:025 volts. 
Wryae ello esate 1] OAL} 9.5 Toe) oe 
Weclanche 2222552 UALS) eS HA Space 
ante Peewee NG OMGn a s- OSes 


The deflection produced by the Daniell cell was 2°59"™ while 
the standard Clark cell moved the mereury column 3°20". 

Thus it is seen, that even with a cathetometer reading only 
to hundredths of a millimeter and having a telescope of low 
magnifying power, values correct to one-half of one per cent 
may be obtained. 

The mereury columns of the electrometer move almost 
instantaneously to the position of equilibrium, and the exact- 
ness with which measurements may be made depends chiefly 
upon the magnifying power of the telescope of the cathetom- 
eter, and the precision with which its scale is graduated. It 
is doubtless possible to determine with this electrometer, the 
electromotive force of a cell correctly to 0-001 of a volt. 

The accuracy with which measurements may be made may | 
be increased somewhat by increasing the number of cells which 
are used in series. When four cells are employed the part of 
the curve corresponding to electromotive forces, which are in 
the neighborhood of 1% volts, is very nearly a straight line, 
and the curve ascends more rapidly than that characteristic of 
three cells. Hence a change in the deflection produced by a 
small variation in the electromotive force is more readily ob- 
served. 

There is another advantage in using more cells than seem to 
be absolutely necessary. If the electrometer is used repeatedly 
to measure electromotive forces which are nearly equal to that 
which produces continuous electrolysis, the curve of the instru- 
ment is less constant from day to day, so that if great accuracy 
is wished for the curve should be redetermined. 

If after long continued use it becomes desirable to refill the 
instrument, it is easily accomplished; since ordinarily the 
mercury need not be replaced, but can be sufficiently cleansed 
by drawing some acid of- the standard solution through the 
electrometer by the aid of the aspirator. 

The results of this investigation may be briefly stated as 
follows: The arrangement of capillary cells in series does not 
alter essentially their behavior, when they are subjected to an 
electromotive force. Hence, in each cell of a series of like 
cells, the fall of potential is the same. Moreover, when a cur- 
rent of electricity passes through this apparatus, the displace- 
ment of the mercury columns varies with the electromotive 
force, according to the same law as in a single cell, so that the 


70 Scientific Intelligence. 


curve showing the relation between the deflections and the 
electromotive force for any cell of the series is of the well- 
known form. Accordingly, by means of cells of proper con- 
struction, a simple and accurate series-electrometer may be 
made; such, also, that its range may be increased by increasing 
the number of component cells. 

These experiments were made in the Sloane Laboratory of 
Yale College, at the suggestion and under the direction of 
Prof. A. W. Wright, to whom I express my thanks, for his 
assistance and kindly encouragement. 

June 1, 1892. 


SCIENTIFIC INTELLIGENCE. 


I. CHEMISTRY AND. PHYSICS. 


1. On the Luminosity of Coal Gas Flames.—An investigation 
has recently been made by Lewes as to the causes of the lumin- 
osity in the flame of ordinary coal gas Previous researches have 
proved beyond question the presence of solid particles in a lumin- 
ous flame; leaving the mode of decomposition by which they are 
set free, for subsequent determination. Figures, obtained by the 
analysis of the flame gases taken at different heights, show that 
the hydrogen in the gas burns first, and that the saturated hydro- 
carbons also undergo a rapid decrease in quantity ; while the 
unsaturated hydrocarbons diminish only very slowly until the 
top of the inner non-luminous zone has been reached, after which 
they quickly disappear. Carbon monoxide also increases largely 
up to the top of the luminous cone. Evidently this slow decrease 
of the unsaturated hydrocarbons in the inner zone suggests that 
the luminosity is due to these compounds, and especially to acet- 
ylene. Experiment showed that in the interior of the luminous 
flame the hydrocarbons begin at once to undergo decomposition 
giving rise to acetylene which constitutes over 70 per cent of the: 
unsaturated hydrocarbons present at the top of the inner non- 
luminous zone. By means of a thermo couple it was found that 
in a flat flame consuming 7 cu. ft. of gas per hour, the temperature 
at a half inch from the burner was 500° and at the commencement 
of luminosity at the apex 1267°; while that at the center was 
1014° rising to 1216° at the luminous edges. In the center of the 
luminous portion the temperature was 1166°, while at the top of 
the flame it was a maximum 1368°. Evidently then in the inner 
non-luminous zone, the hydrocarbons heated up by the combus- 
tion of the hydrogen and some of the methane, undergo certain 
changes which result in their conversion into acetylene ; and this 
being an endothermic compound, breaks up when a suflicient 
temperature is attained. Owing however to oe diluting action 


Chemistry and Physics. TA 


of the nitrogen and other flame gases this does not take place 
antil the top of the non-luminous zone is reached, where at a tem- 
perature of a little over 1000° the decomposition occurs with an 
increase of temperature, and the liberated carbon, being heated to 
incandescence, gives the luminosity to the flame. The author 
divides the flame into three zones. In the inner zone the tempera- 
ture rises to 1000° to 1100° at the apex, and here the gaseous con- 
stituents undergo various decompositions culminating in the pro- 
duction of acetylene; and some hydrogen and carbon monoxide. 
In the middle or luminous zone the temperature ranges from 1100° 
to 1300°, and here the acetylene formed in the inner zone is 
decomposed with the deposition of carbon, which at the moment 
of separation is heated to incandescence by its own combustion as 
wellas by that of the hydrogen and carbon monoxide and so gives 
luminosity to the flame. In the outer zone the cooling and dilu- 
ting influence of the entering air render a thin layer non-lumin- 
ous and finally extinguishes it. With reference to the loss of 
luminosity in the Bunsen flame the author attributes it: (1) to 
the chemical activity of the oxygen of the air which burns up the 
hydrocarbons before they can form acetylene; (2) to the diluting 
influence of the nitrogen which increases the temperature required 
to form acetylene; (3) to the cooling effect of the air introduced. 
—J. Chem. Soc., 1xi, 322, April, 1892. Ge Fi B. 
2. On the measurement of Osmotic Pressure. —It is well 
known that the osmotic pressure of a salt solution calculated 
from the electrolytic dissociation formula of Avrhenius does not 
agree with that observed directly, but is always smaller. Thus 
for potassium nitrate, the osmotic pressure as observed by Pfeffer 
in a solution containing 0°8 gram in 100 grams, is 1304™™, while 
that calculated is 2530. For a one per cent solution of potassium 
sulphate, the observed value is 1758™™, the calculated is 2480. 
TamMANN has investigated the cause of this, and has pointed out 
the fact that it is due to the permeability of the membrane of 
copper ferrocyanide used in the experimental determinations. 
Obviously if this membrane is not perfectly impermeable to the 
salt employed (or to its ions) the observed osmotic pressure will 
be less than it really is. lence by determining the rate at which 
the salt is diffused through the membrane a correction may be 
obtained for the observed values. Moreover, according to the 
author, the copper ferrocyanide membrane may be obtained in 
two distinct forms. The first of these when fresh is transparent, 
elastic and extremely thin and allows water to pass through it 
freely. The second is opaque, dark brown in color, only slightly 
elastic and much less permeable to water. This form is produced 
when the solutions of copper sulphate and potassium ferrocyanide 
remain in contact with each other for a long time on the sur- 
face of a porous tile. The presence of sodium sulphate in the 
copper sulphate solution facilitates its formation. For the best 
results the solutions should be more concentrated than those sug- 
gested by Pfeffer; say a normal solution of copper sulphate and 


72 © Scientific Intelligence. 


a one-third normal solution of potassium ferrocyanide. The 
author proposes a moditication of Pfeffer’s method of determining 
osmotic pressure. It is based on the fact that if two solutions 
having different osmotic pressures be placed on opposite sides of 
a seml-permeable membrane, water will flow through the mem- 
brane into the solution whose osmotic pressure is the higher; so 
that by applying external pressure till balance is attained, the 
differential osmotic pressure is determined. The apparatus used 
is figured in the paper.—Zeitschr. physikal.. Chem., ix, 97, Feb., 
1892. ; G. F. B. 

3. On the Coefficient of Molecular Depression of Phenol.— 
Two numbers have been given for the molecular depression-con- 
stant of phenol; one by Raoult, obtained with phenol of a melt- 
ing point 37°8°, by means of naphthalene, camphor, benzoic acid 
and thymol, which has the value 67°5; the other by Eykmann, 
which is 76. JvumLLaRD and CurcuHop, using a synthetically pre- 
pared specimen of phenol having a melting point 41°2°, find that 
the molecular depression-constant varies with the dissolved sub- 
stance. Thus for example for water, 6-naphthol, paratoluidine, 
aniline, nitrobenzene, phthalic anhydride, diphenic anhydride, a- 
naphthylamine, amyl alcohol, 1icinic acid and salol, they get the 
value 68°5; while for normal ethereal salts, especially those of 
dibasic acids such as methyl] diphthalate, ethyl succino-succinate, 
ethyl malonate, ethyl succinate, ethyl aceto-acetate, the value ob- 
tained is 75°81. In their experiments the amount of depression was 
determined in a long-necked thick glass flask of 40-50°° capacity, 
by noting the solidifying point of the phenol after the addition 
of the other substance.— Bull. Soc. Chen., Til, vi, 237; J. Chem. 
Soc., |xii, 555, May, 1892. G. F. B. 

4. On the determination of Vapor Density under Diminished 
Pressuré.—ScCHAuLL has devised a method of determining the 
density of a vapor under diminished pressure, based on the fact 
that when gas is evolved in a bulb uniformly heated, this bulb 
being provided with a manometer, the increase of pressure is 
independent of the point at which the gas is evolved and is 
exactly proportional to the amount of gas or vapor produced, 
provided the space shut-off by the manometer may be considered 
constant. It is a modification of the method already described 
in this Journal.* The bulb used is moderately thick, of about 
150°° capacity, having two constrictions equidistant in its length 
to hinder the diffusion of the vapor into the neck, and provided 
with a lateral tube connected with a manometer, and interme- 
diately with a bell jar for the evolution of carbon dioxide. For 
the method of using it and the calculation we must refer to the 
original paper.—/. prakt. Ch., I, xlv, 134, 1892. G. F. B. 

5. SJuhrbuch der Chemie. Bericht tiber die wichtigsten Fort- 
schritte der reinen und angewandten Chemie, herausgegeben von 
Ricuarp Meyer, Braunschweig. I Jahrgang, 1891. 544 pp., 
Svo. Frankfurt a. M., 1892 (H. Bechhold).—This new Jahrbuch 


* This Journal, ITI, xl, 415, November, 1890. 


Chemistry and Phystes. Pee 


is designed to present the most important steps of progress in the 
various departments of chemistry for the past year. . It differs 
from other publications of the kind, particularly the invaluable 
and long honored Jahresbericht der Chemie, in that it does not 
attempt an exhaustive treatment of the subject, but does give a 
well-selected digest, brief enough to be issued very promptly. 
This first volume was actually put on sale but a few months after 
the close of the year whose record it gives; this is a remarkable 
achievement and if this promptness can be maintained it will 
ensure the success of the work. The volume is divided into 
fourteen chapters written by nearly as many well-known authors 
most of whose names appear on the title page as regular co- 
editors. The following are subjects of some of the chapters: 
Physical Chemistry by W. Nernst, also Inorganic by G. Kriiss, 
Organic by C. A. Bischoff, Physiological by F. Réhmann, ete. ; 
on Metallurgy by E. F. Diirre, Technology of Carbohydrates and 
Fermentation processes by M. Mircker and L. Biihring, and of 
Fats by R. Bendedikt; Photography by J. M. Eder and E. 
Valenta. The book is handsomely printed and well bound in 
cloth. 

6. Chemical calculations with explanatory notes, problems and 
answers. Specially adapted for use in Colleges and Science 
Schools, by R. Lroyp Wauirerey; with a preface by F. Clowes. 
100 pp. London and New York, 1892 (Longmans, Green & Co.) 
—This is a useful collection of well selected problems under the 
different departments of chemistry, accompanied by full explana- 
tions of the methods involved and the solution of typical cases ; 
the answers to the problems are given ina supplementary chapter. 

7. Contributions to the knowledge of the discharge of the 
Ruhmkorff coil ; by Tom Mout; translated from the Beiblitter 
za den Annalen der Physik und Chemie, xv, No. 2, 1891.—From 
the older investigations on the nature and duration of induction 
currents the author gives a description of the methods and results 
of Nyland, Rood, Cazin, Mayer and Holtz. He himself employed 
a photographic method; an image of the spark was thrown by a 
small concave mirror on a rapidly revolving circular disc which 
carried a sheet of sensitive paper. The time of closing the pri- 
mary current and the velocity of rotation of the dise were regis- 
tered on a revolving cylinder, which also received the trace of a 
vibrating tuning-fork. A large induction coil was used, its length 
being 57°, its diameter gems the strength of the primary cur- 
rent was measured with a tangent compass. As a general thing 
the electrodes furnishing the spark were connected with a Leyden 
jar having an interior coating of about 772 square centimeters. 
The external resistance in the secondary circuit was always the 
same and quite small. 

By a study of the photographs thus produced the author ascer- 
tained the entire duration of the discharge, the intervals of time 
between the partial discharges and their mean, and this work was 
performed for sparks of various lengths, for primary currents of 


74 Scientific Intelligence. 


different strength, for various capacities of the Leyden jar and 
for different forms of electrodes. 

It was found that as the length of the spark increases, the 
total duration diminishes, which is also the case with the number 
of partial sparks composing it, but the interval of time between 
the partial sparks increases.. For long sparks the mean interval 
of time uw between the partial sparks, was proportional to the 


square root of the spark length, 4/7. For short sparks, « appears 
to be greater than this law would demand; also the time-intervals 
between the two first partial discharges increase, as it appears, a 
little more rapidly than 1/7. When the length of the spark was 
made less than 0°75"™ sparks were produced even on completing 
the primary circuit, but in this case the number of the partial 
discharges was much smaller and their mean distance apart 
greater, than when the circuit was broken. 

When the strength of the primary current, was diminished the 
number of the partial discharges and the total duration were 
quickly curtailed, but the mean time-interval of the partial dis- 
charges stood in an inverse ratio to the current’s strength. This 
applies also to the value of the first time-interval. 

As the capacity of the Leyden jar was increased the discharge 
consisted of a series of partial sparks with increasing time-inter- 
vals. When the capacity was diminished the number of the 
partial sparks increased and the discharge finally appeared partly 
continuous. Since this continuous light did not sufficiently affect 
the sensitive paper, the author made direct observations with a 
revolving mirror, and ascertained that the aureole was preceded 
by a few and followed by a greater number of partial sparks. 
As the capacity was made smaller, the number of these sparks 
was diminished, till finally the aureole formed the greatest part 
of the discharge. As long as the discharge was entirely disrup- 
tive, a diminution of the capacity diminished the time-interval 
between the partial sparks, but increased the total duration. For 
short sparks, however, the total duration appears to approach a 
constant quantity and to be independent of the capacity ; it is 
about 0°023 sec. 

As the electrodes were made more pointed the entire duration 
increased, also the number of the partial sparks, but the mean 
time-interval between them was diminished. When the electrodes 
were made very sharp, completion of the primary current pro- 
duced sparks, but their number was small. All the experiments 
show that the time-interval between the partial sparks increases 
toward the end of the discharge, the last interval often being twice 
as great as its predecessor. The author has expressed the rela- 
tion of the time-intervals, reckoning from the first partial spark, 
by an exponential function, and the agreement: between calcula- 
tion and observation is very good if the last three time-intervals 
are neglected. 

The results in their main features agree very well with the 
observations of Rood, but differ from the others to a degree that 


Chemistry and Physics. 75 


is not insignificant. Mr. Moll studied the cause of these varia- 
tions, and repeated the work of Nyland, Mayer and Holtz with 
arrangements similar to those used by these investigators. It 
proved in all these experiments that the nature of the discharge 
was a little altered by the mode of observation itself, since in the 
experiments of Nyland and Mayer the spark struck through a 
sheet of paper, and in those of Holtz the spark itself was in rota- 
tion. From these defects the arrangement of Rood is free. 

Ifit is desired to give an explanation of the discharge of a 
Ruhmkorff inductorium, it is necessary at the outset to decide 
whether the partial sparks are directed in the same way or not. 
Mr. Moll allowed the sparks to fall ona rotating dise of paper, 
the electrodes on either side of the paper being at slightly differ- 
ent distances from the center of the disc. The holes made by the 
sparks were always opposite one of these electrodes, consequently 
all the sparks have the same direction. 

Starting from this fact the author endeavors to explain the 
phenomena of the discharge by the assumption that the electricity 
cannot flow with sufficient rapidity to the electrodes, and that 
partial sparks are produced as soon as the difference of potential 
has reached a certain value, dependent on the distance of the 
electrodes apart, etc. The approximative statements which with 
the help of known facts one can easily deduce from these condi- 
tions, agree, as a whole, very well with the results previously 
found by experiment.—k. A. 

8. Photography in Colors.—The Comptes Rendus for Feb- 
ruary, 1891, contained a note on color photography describing a 
method employed by M. G. Lippmann, who had been able to pro- 
duce photographically the image of the spectrum with all its 
colors. M. G. Lipwanyn has communicated turther results to the 
Comptes Rendus for April 25 (No. 17, vol. exiv). The following 
is a translation of his last communication:—In the first communi- 
cation which I had the honor to make to the Academy on this 
subject, I stated that the sensitive films that I then employed 
failed in sensitiveness and isochromatism, and that these defects 
were the chief obstacle to the general application of the method 
that I suggested. Since then I have succeeded in improving the 
sensitive film, and, although much still remains to be done, the 
new results are sufficiently encouraging to permit me to place 
them before the Academy. : 

On the albumen-bromide of silver films, rendered orthochromatic 
by azalin and cyanin, I have obtained very brilliant photographs 
of spectra. All the colors appear at once, even the red, without 
the interposition of colored screens, and after an exposure varying 
from five to thirty seconds. On two of these clichés it has been 
remarked that the colors seen by transmission are very plainly 
complementary to those that are seen by reflection. The theory 
shows that the complex colors that adorn natural objects ought 
to be photographed just the same as the simple colors of a spec- 
trum. The four clichés that I have the honor of submitting to 


76 Scientific Intelligence. 


the Academy represent faithfully some object sufficiently diverse, 
a stained glass window of four colors, red, green, blue, yellow: 
a group of draperies; a plate of oranges, surmounted by a red 
poppy; a many-colored parrot. These show that the shape is 
represented simultaneously with the colors. The draperies and 
the bird required from five to ten minutes’ exposure to the electric 
light or the sun. The other objects were obtained after many 
hours of exposure to a diffuse light. The green of the foliage, 
the gray of the stone of a building are perfectly reproduced on 
another cliché. The blue of the sky, on the contrary, was repre- 
sented as indigo, It remains then to perfect the orthochromatism 
of the plate, and to increase considerably its sensitiveness.”— 
Nature, May 5, 1892. on: 

9. Dispersion of the Ultra Red Rays.—At a meeting of the 
Physical Society in Berlin, March 11, Dr. Rupgens discussed this 
subject. He had extended his observations from wave-length 
57 to wave-length 8. The curves representing changes in 
index of refraction do not agree with Professor Langley’s views 
on this subject. To wave-length 5°34 Rubens’s curves coincide 
with those of Langley. But beyond this point the interpolations 
of Professor Langley do not agree with Rubens’s observations. 

Janie 

10. Electrical Resistance of the Human Body.—The frequent 
controversies which have taken place upon this subject, especially 
in relation to accidents from electrical currents, make a late paper 
by M. von Frey (Verh. d. X. Congr. f. innere Medizin, Wies- 
baden, 1891, p. 377) of considerable interest. The author em- 
ployed Kohlrausch’s method of determination of the electrical 
resistance of electolytes. The metric length in Kohlrausch’s ap- 
paratus was supplanted by a circularly formed channel, the ends 
of which were not joined. This channel was filled with a sul- 
phate of zine solution. The conducting electrodes were greatly 
increased in size over those employed by Kohlrausch. With 
large electrodes suitably proportioned to the extent of surface of 
the wet hands, the resistance of the body from hand to hand was 
found to be small, 300 to 400 ohms. The author discusses the re- 
lation between the size of electrode and the resistance of the 
human skin, According to him the seat of the electric polariza- 
tion of the body is in the outer surface and layers of the skin.— 
Beiblitter Ann. der Physik und Chemie, No. 4, 1892, p. 217. 

ap 


Il GroLocy AnD MINERALOGY. 


1. The History of Volcanic Action in the Area of the British 
Isles, by Sir ARcHIBALD GeIKIE. Anniv. Address Geol. Soe. 
London, Feb. 19, 1892. 120 pp. 8vo.—This second part of Sir 
Archibald Geikie’s Memoir on volcanic action in the British 
Islands treats of the evidences of such action and the volcanic 
phenomena and rocks, in connection with the Old Red Sandstone; 


Geology and Mineraloyy. 77 


the Devonian of England and Wales; the Carboniferous, and the 
Permian. After the Permian period, no volcanic or igneous 
eruptions occurred again until the Tertiary. 

In the author’s summary of the remarkable facts he has pre- 
sented, the following are some of the conclusions stated. The 
belts, of volcanic activity are ranged nearly north and south, 
along the length of the British Isles from the south of Devon- 
shire to the Shetlands; but no trace of them occurs through 
eastern England, from Berwick to Exeter, if we except the dikes 
in the northern counties. Moreover, the Central Highlands of 
Scotland were exempt through all the time. 

In this western tract, volcanic activity was almost continuous 
from the Archzean to the close of the Paleozoic; and reappeared 
in the Tertiary. The absence from the Mesozoic accords with 
the general quiet over the European continent. 

The sites of the eruptions were not determined by lines of 
faults; but there is this remarkable fact that they were confined 
to the low grounds and valleys, such as the great depression 
between the Highland Mountains and the Southern Uplands, 
which was the chief center of volcanic activity in Scotland during 
the later half of the Paleozoic. Again in the Tertiary, the great 
outpouring took place in the long depression between the Outer 
Hebrides and the mainland of Scotland. The volcanic action 
occurred on sinking rather than rising areas, that is, on areas 
where a great thickness of sediments were formed. There was a 
gradual diminution in the extent of the eruptions from the Silu- 
rian to the Permian, when there were only small scattered vents. 
In the earlier Paleozoic lava-eruptions were most abundant, while 
in the later in very many cases there were only ejections of ashes, 
making tufa-cones. 

In each eruptive period the Tertiary included, there was a 
change sooner or later from basic to acidic lavas. When a second 
period commenced in the same region there was usually again the 
Same succession—a beginning with basic and an ending with 
acidic. The eruptions of the Northwest Highlands were solely 
fissure eruptions; and the same kind prevailed in the Tertiary. 
At other periods the eruptions were connected with true volcanic 
vents. <A great crater-like cavity was sometimes left, that became 
filled with the following rock-deposits. 

2. New Jersey Geological Report for 1891, Joun C. Smock, 
State Geologist. 270 pp. 8vo. Trenton, N. J., 1892.—This volume 
coutains an extended account of the drift formations of New 
Jersey by Prof. R. D. Salisbury, illustrated by several photo- 
types of the region of the terminal moraine and of other bowlder 
scenes, and also by many wood-cuts, and a map. The paper is an 
important contribution to the general subject of glacial phe- 
nomena. 

Mr. Lewis Woolman reports on the horizons of Artesian wells 
in Southern New Jersey and other parts of the Atlantic border. 
He mentions the occurrence of one or two upper horizons de- 


78 Scientifie Intelligence. 


pendent on clay deposits, occurring in Cape May County; three 
wells at Sea Isle City affording water at depths of 35, 150 and 
160 feet. At a greater depth varying from 382 to 697 feet, in 
the region.of Atlantic City, water is obtained from fine hard clays 
and sandy clays over 300 feet thick; and this 3C0-foot stratum 
contains, through nearly every foot, great numbers of diatoms, 
so that it is a Diatomaceous clay-bed. The bed consequently is 
easily identified. Two levels of water-supply occur in it, one 
midway in it, and the other just below. The former at Atlantic 
City has a depth of 550 feet. The depth increases to the south- 
east at a rate of 25 or 26 feet a mile. A water-horizon beneath 
the clay-bed at Atlantic City has a depth of 700 to 720 feet. 
This Diatomaceous clay-bed extends under part of Delaware and 
Maryland. In the New Jersey Geological Report for 1890 Mr. 
Woolworth mentions the large Diatom bed near Richmond, Vir- 
ginia, described by Prof. W. B. Rogers, as of the same charac- 
ter and as possibly related in position. He cites from Prof. 
Rogers the fact of diatoms brought up from a depth of 558 feet 
in a well-boring at Fortress Monroe. 

3. Progress “of the Kentucky Geological Survey, Joun R. 
Procter, State Geologist.—A Report of progress on the work of 
the Survey for 1890, 1891 (to January, 1892) has been recently 
published. It announces that Prof. Crandall has been continuing 
the investigation of the Coal region of Eastern Kentucky, with 
reference to a general report on the coal-field as a whole, in which 
the extension and the equivalency of the various coal-beds will be 
treated. The study of the Coal-field and of the general geology 
of Western Kentucky has also gone forward under Prof. Lough- 
ridge, J. H. Crump, J. B. Hoeing and E. O. Ulricli, and their 
reports will soon be published on “Livi ingston, Meade, Warren, 
Caldwell and Crittenden Counties. 

4. Kentucky Geological Survey: Report on Petroleum 
Natural Gas and Asphalt Rock of Western Kentucky; by 
Epwarb Orton. 233 pp. Svo. Frankfort, Ky.—Prof. Orton, after 
reviewing in an instructive way the history of petroleum dis- 
coveries and the origin of mineral oil and gas, treats of their 
modes of geological occurrence, and the bearing of the facts on 
practical questions connected with exploration for gas and oil. 
Composition, fuel-value and uses are other subjects considered. 
Next the facts connected with the geology of Kentucky, its bor- 
ings, wells, gas and petroleum, are given in detail. There is no 
better authority on the subject than Prof. Orton. A fine colored 
map of the geology of Kentucky accompanies the Report. 

5. Geological Survey of Alabama.—Bulletin No. 2 (1892), 
on the Phosphates and Marls of Alabama, by Prof. E. A. Smith, 
State Geologist (82 pp. 8vo) has been issued. 

6. The Mannington Oil-field and the history of its develop- 
ment, by I. C. Wuirr (G. 8. Amer., iii, 187.)—In this excellent 
paper Prof. White sustains the view brought out by him first in 
1885, that success in boring for gas in Pennsyly ania depends as a 


Geology and Mineralogy. 1 


general thing, on the existence of an anticline in the subjacent 
rocks. 

7. New Lower Silurian Lamellibranchiata, chiefly from Min- 

nesota rocks ; E. O. Utricn. From the Nineteenth Ann. Rept. 
Geol. and Nat. Hist. Surv. of Minnesota, March, 1892.—Thirty 
new species are added to the known fauna of these rocks. They 
are referred mainly to the genera Tellinomya, Modiolopsis, and 
Cypricardites. A new genus, Plethocardia, is proposed for two 
species related to the Cyrtodonta cordiformis of Billings. The 
author recognizes the confusion existing among the genera of 
Silurian lamellibranchs and his references are therefore somewhat 
provisional. ©. E. B. 
_ & Der Peloponnes, Versuch einer Landeskunde auf’ geolo- 
gischer Grundlage, nach Ergebnissen einiger Reisen von Dr. 
ALFRED PHILIPPSON. pp. 273-642, 8vo. Berlin, 1892 (R. Fried- 
lander & Sohn).—This volume is the concluding Part II of the 
valuable work on the Peloponnesus noticed in vol. xlii of this 
Journal (page 173). It continues the topographic description of 
the country, and then treats of the geological structure, climate, 
vegetation, fauna, and other topics of general interest. The 
illustrations include maps and sections and a series, of four large 
colored topographic maps, which are both hypsometric and 
bathymetric. 

9. Chiastolite in fossiliferous metamorphic slates of Portugal. 
—In an Upper Silurian slate of the Province of Minho, near Val- 
longo, Portugal, J. F. N. Deteapo has found along with Grap- 
tolites, multitudes of small crystals of chiastolite. Further, a 
Lower Silurian slate of Serra de Marao, containing a specimen of 
the trilobite Zaenus Lusitanicus with portions of its test silici- 
fied, and a cast of a Redonia (probably &. Duvaliana Rou.), 
contains crystals of chiastolite in the rock and also in the casts of 
the fossils. Kjerulf has described a similar case from near Ekern, 
in the inferior part of the Lower Silurian, where the rock, which 
is profoundly altered, contains large numbers of chiastolite crys- 
tals along side of the graptolites. 

10. Striated Garnet from Buckfield, Maine ; by W.S. Baytey 
(communicated).—In glancing over the literature of garnets in 
Hintze’s Handbuch der Mineralogie so few were the notices of 
striated garnets met with, that it is thought worth while to men- 
tion the existence of good examples of them in large numbers at 
Buckfield, Oxford Co., Maine. Unfortunately but one specimen 
from this locality remains in the writer’s possession, but this is so 
similar in appearance to others obtained from the same place that 
its description will serve as a description of nearly all found 
there. The crystal to which reference is made is an icositetra- 
hedron (211) about two inches in diameter, modified by small 
faces of the dodecahedron (110). All the planes are deeply 
striated parallel to the combination edge, 211: 110, and these 
striations are so deep in the icositetrahedral faces that the reflec- 
tions of the dodecahedron may easily be obtained from them. In 


80 Scientific Intelligence. 


consequence of this oscillation between the two planes mentioned, 
the crystal appears to be made up of alot of lozenge-shaped 
plates piled one upon another, with the smallest forming the 
dodecahedral bounding plane of the er ystals, and the edges of 
the pile the deeply striated icositetrahedral faces. In small fr ag- 
ments the mineral is transparent and has the usual deep red color 
of almandine. Its exact method of occurrence is unknown. 

11. Blowpipe Analysis by J. LanpAvER. Authorized English 
edition by James Taytor. Second edition, revised and enlarged. 
173 pp. 16mo. London and New York, 1892 (Macmillan and 
Co.).—This excellent little book has had a well-deserved recogni- 
tion since the issue of the first edition in 1879, and in the present 
new edition it is still better equipped for usefulness. 


III. MisckLLANEOUS SCIENTIFIC INTELLIGENCE. 


1, The Great Karthquake of Japan, 1891; by Prof. Joan 
Mitng, F.R.S., and Prof. W. K. Burton, C.E., with plates by 
K. Ocawa. Yokohama, 1892.—On the morning of October 28, 
1891, there occurred in Japan an earthquake, which, even in that 
much shaken country, is already known as “the Great Earth- 
quake.” Its greatest force was exerted in the neighborhood of 
Gifu and Nagoya, towns some fifteen miles west of Tokyo, but it 
was felt from Sendai on the north to Nagasaki on the south over 
an area of 92,000 square. miles, and the area of complete destruc- 
tion of buildings was 4200 square miles. The first and most 
severe shock occurred at Gifu at 6" 38™ 11° on the morning of 
October 28, and was followed by numerous minor shocks to the 
number of several thousand in the twelve days next following, 
One authority stated the number of persons killed in the prefec- 
tures of Aichi and Gifu at 7528, the wounded 9458, houses totally 
destroyed 82,000, partially destroyed 23,000, damage to property 
$20,000,000. A recent letter from Prof. Milne, puts the dead at 
10,000 and the loss at $50,000,000. 

It is this great earthquake which is illustrated in the series of 
plates whose title is given above and which forms an oblong 
quarto volume 29™ x 41 in size. The plates are heliotype 
copies of photographs, all but three of which were made by the 
authors for the Imperial University of Japan, and are copy- 
righted in its name. It is published by Lane Crawford & Oo., 
Yokohama. ‘The press work was done in Tokyo, and the paper 
on which it is printed is a product of the very district shaken 
by the earthquake. Indeed there was some delay in printing 
proofs owing to the difficulty of getting the paper in the dis- 
organized state of all manufactures. It is handsomely bound in 
cloth and in general make up the book will compare favorably 
with the product of any western press. The first edition of 1000 
copies has all been sold and a second edition with a few additional 
plates is in preparation. 


Miscellaneous Intellagence. 81 


it opens with ten pages of introduction on the nature of earth- 
quakes in general and their relation to Japan, with brief mention 
of the salient incidents of the recent disaster, from which some of 
the statements above are taken. This is foliowed by thirty plates, 
varying a little in size, but mostly about 32°" & 21°5°™ and each 
plate is accompanied by a brief description. These plates give 
very impressive illustrations of the destruction caused by the 
earthquake. / 

2. Congress of Mathematicians and Astronomers.—In con- 
nection with the Exposition to be held at Chicago in 1893, a 
“ World’s Congress Auxiliary” has been formed for the purpose 
of organizing a series of Congresses or Conventions to be held 
during the progress of the Exposition, which will bring together 
the leading scholars of the world for the mutual interchange of 
ideas on topics bearing on human progress. 

As a part of this general plan a preliminary address has been 
recently issued from the division of Mathematics and Astronomy, 
of which Prof. George W. Hough is chairman, inviting the codpera- 
tion of all persons and societies interested in the department of 
physical science. Three chapters are proposed: I in Pure Math- 
ematics, II in Astronomy, and III in Astro-physics. A series of 
topics is given in the circular by the committee, which are sug- 
gested for consideration. Advice and suggestions are desired 
as to the general conduct of the convention, and in particular as 
to the scientific questions to be discussed, and persons to present 
them. The suggestions and recommendations invited will be 
used in the formation of the program for the Congress. 

The Chairmen of the Special Committees of the several chapters 
under the charge of the General Committee, are as follows : 

Pure Mathematics, Prof. E. H. Moore, Chicago University, 
Chicago, Il. 

Astronomy, Prof.G. W. Hough, Dearborn Observatory, North- 
western University, Evanston, Ill. (who is also general chairman), 

Astro-Physics, Prof. George E. Hale, Kenwood Astro-Physical 
Observatory, Chicago, IIL. 

3. American Association.—The 41st meeting of the American 
Association for the Advancement of Science will be held in 
August next, commencing with Wednesday, the 17th, at Roch- 
ester, New York. All abstracts of papers should be sent to the 
Permanent Secretary, F. W. Putnam, Salem, Mass., until Aug. 
7th, and after that time, to Powers’ Hotel, Rochester, the hotel 
headquarters of the Association. The President of the meeting 
is Prof. Joseph LeConte, of Berkeley, California. The Local 
Secretary, Prof. H. L. Fairchild of the University of Rochester 
will give information, if desired, with regard to local arrange- 
ments, hotels, railway rates, etc. The Register will be opened i in 
the University of Rochester on the 15th of August, and the 
meetings will be held in the buildings of the University. 

The “Geological Society of America will hold its August meet- 
ing at the same place on Monday and Tuesday, Aug. 15 and 16, 


82 Miscellaneous Intelligence. 


Prof. G. K. Gilbert, President; The American Microscopical 
Society, on Aug. 9, 10, 11, 12, Prof. M. E. Ewell, Prest. ; The 
Society for the promotion of Agricultural Science, on Aug. 15, 
16, Prof. I. P. Roberts, Prest., and the Association of Economic 
Hntomologists, on Aug. 15, 16, Dr. J. A. Lintner, President. 


OBITUARY. 


Lewis Morris RurserrurpD died on the 30th of May at his 
home, Tranquillity, New Jersey, in the seventy-sixth year of his 
age. He was born at Morrisania, N. Y., Nov. 25th, 1816, and 
was graduated at Williams College in 1834. He at first devoted 
himself to the practice of the law, but in 1843 he turned into the 
field of physical science in which he was to accomplish such good 
work. His interests lay chiefly in the direction of stellar pho- 
tography and spectroscopic work, and in 1862 and 1863 he pub- 
lished (in this Journal) several important papers upon these sub- 
jects. One of these discussed the spectra of the stars, moon and 
the planets, which was one of the early contributions in this line 
and contained the first attempt to classify stars according to 
their spectra. He constructed about the same time a telescope 
for photographic work with specially corrected objective of 114 
inches aperture, and in 1868 one of 13 inches; with the latter he 
made many admirable negatives of the sun, moon and star 
groups; his photographs of the lunar surface are remarkable for 
their beauty and perfection. He also constructed a micrometer 
for astronomical measurements, and in connection with photo- 
graphs of stellar groups he made a large series of measures which 
in many cases constitute the earliest accurate observations of the 
clusters in question. A paper has recently been published* upon 
the “Rutherfurd Photographic Measures of the Group of the 
Pleiades,” and it is stated that others are to follow giving the 
results of the Rutherfurd measures. Another work of great 
importance was the construction in 1890 of an accurate ruling 
engine with which he ruled diffraction gratings for spectroscopic 
work; these “Rutherfurd gratings” for many years played as 
important a part as do the “ Rowland gratings ” to-day. 

Mr. Rutherfurd was one of the original members of the National 
Academy of Sciences. He was named by the President of the 
United States as one of the American delegates to the Intérna- 
tional Meridian Conference that met in Washington in October, 
1885, and he took a prominent part in the work. In 1887 he was 
invited by the French Academy of Sciences to become a member 
of the International Conference on Astronomical Photography, 
held in Paris in 1887, and was appointed by the President of the 
National Academy of Sciences as its representative, but was 
obliged to decline the honor on account of his failing health. He 
was an Associate of the Royal Astronomical Society and, besides 
being a member of several scientific societies in this country and 
abroad, was the recipient of many medals, orders and diplomas. 


* By Harold Jacobs in the Annals N. Y. Acad. Sci., vol. vi, pp. 239-330, Feb. 
1892. 


NEW SHIPMENTS OF MINERALS. 


FROM ENGLAND:—The finest and largest group of Phantom Twin 
Calcites ever found. Beautiful new Calcites and Barites sifted 
with Pyrite!! Splendid large and small Egremont and Stank 
Mine Calcite groups, &c., &e. 

FROM SWITZERLAND :—Elegant Smoky Quartz in twisted crys- 
tals, large and small crystals, singly and doubly terminated, 
groups and loose crystals. Rose Fluors, 50c. to $10.00 ; Brook- 

“ites, Anatase, Magnetite, Adularia, Yellow Sphenes, &c. 

FROM HUNGARY :—The finest Laumontites ever imported. Some 
crystals 12 inches in length. 
FROM SWEDEN :—A very choice lot of crystals of the new and 
rare mineral, Eudidymite, a very interesting monoclinic hydrous 
silicate of beryllium and sodium, AJso many other very rare 
Scandinavian minerals. The best lot we have ever had, includ- 
ing such things as Crystallized Native Lead, Crystals of Kuxenite, 

&e. ; 


MAMMOTH VESUVIANITE CRYSTALS! 
A New Lot! 


: 
In announcing two months ago a crystal of Vesuvianite from Arkan- 
sas, weighing 22 lbs., we stated our belief that is was the largest ever 
found. Now we have one weighing 54 lbs. and several others of very 


large size. Two months’ work has been given to the locality by our 


collector, and the result is a marvellous shipment. 


Fine Geniculated Rutiles! 


-An elegant lot accompanied the Vesuvianites. The specimens are 
exceptionally brilliant and well developed. 


Brief Mention of a Few Rare Specimens. 


Stibnite, Japan, large group of superb terminated crystals, $50.00. 
Topaz, Siberia, a $25.00 crystal. 
Aguilarite, Mexico, group of fine crystals, $25.00; another, $37.50. 
Smithsonite, Greece, group of long brown stalactites, $20.00. 
Proustite, Chili, elegant group of large crystals, $75.00. 

Scores of other equally fine specimens in stock. 


DANA’S NEW “SYSTEM OF MINERALOGY.” 
Sixth Edition, 1197 pp. ; 1425 cuts; price, $12.50. 

This great work is now ready, and we offer it at a discount of 20%, o1 
only $10.00 net. j 

It is not a mere revision, but the entire work has been re-written. It 
contains half more matter than-the 5th edition, makes fundamental 
changes in the classification, etc. Our second full circular giving ex- 
paced extracts from the preface, sent free. We earnestly solicit your* 
order. ; 


_100 pp. Illustrated Catalogue, 15c.; cloth bound, 25c.; Supplement, 2c. ; 
Circulars free. 


GEO. L, ENGLISH & CO., Mineralogists, 
733 & 735 BROADWAY, NEW YORK CITY. 


IX.—Occurrence of a Quartz Bowlder in the Sharon Coal. of 


X.—A Method of Increasing the Range of the Capillary 
Electrometers: by J. W.aHTEMORE: 7) 5) a ee 64. 


Obitutry.—LEWwis MORRIS RUTHERFURD, 82. 


CONTENTS. 


1L—Polybasite. and Tennantite fed the Mollie Gibson 
Mine in Aspen, Col.; by S. L. PEnrietp and 8. H. 


PRARCIE (ty 21585 WT ee eh ee De ae 
IiI.—Post-Laramie Deposits of Colorado; by W. Cross... 19 


TV.—Alkali-Metal Pentahalides; by H. L. Wetts and H. 
L. Wueeter. With their Crystallography; by 8. L. 


Peepers 28” SNR Ss oh Ce Lee ee ae 42 
V.—Fossils in the “ Archean” rocks of Central Piedmont 

Vareinia:> by Nv. DaRTON i +2 4 26 eee hee ee 50 
VI.—wNotes on the Cambrian Rocks of Virginia and the — 
: Southern Appalachians; by C. D. Watcorr_--.---.--- 52s 
VIL —Synthesis of the minerals Crocoite and Phenico- 

chroites Jby C: LUDEKING 5/3 2255 2597.22 Cee 57 


VIIL—A Hint with respect to the Origin of Terraces in 
Glaciated Revions: *by W.o8.7 Tare: ose 25) ee 59 


Northeastern Ohio; by EH, Orron, 225. 22225 ees 62 


SCIENTIFIC INTELLIGHNCE. 


Chemistry and Physics.—Luminosity of Coal Gas Flames, Lewes, 70.—Measure- 


ment of Osmotic Pressure, TAMMANN, 71.—Coefficient of Molecular Depression 
of Phenol, JuILLARD and CurcHoD: Deternunation of Vapor Density under 
Diminished Pressure, SCHALL: Jahrbuch der Chemie, R. MEYER, 72.—Chemical 
Calculations with explanatory notes, problems and answers, R. L. WHITELEY: 
Contributions to the knowledge of the discharge of the Ruhmkorff coil, Tom 
Mott, %73.—Photography in Colors, G. Lippmann, 75.—Dispersion of the 
Ultra Rec Rays, Dr. RusBnns: Hlectrical Resistance of the Human Body, M 
von FREY, 76. 


Geology and Mineralogy.—History of Voleanic Action in the Area of the British 


Isles, A. GEIKIE, 76.—New Jersey Geological Report for 1891, J. ©. Smock, 
77.—Progress of the Kentucky Geological Survey, J. R. Proorer: Kentucky 
Geological Survey: Report on Petroleum Natural Gas and Asphalt Rock of 
Western Kentucky, H. Onton: Geological Survey of Alabama, Smita: Manning- 
ton Oil-field and the history of its development, I. C. Wurrz, 78.—New Lower 
Silurian Lamellibranchiata, chiefly from Minnesota rocks, E. O. Unricn: Der 
Peloponnes, Versuch einer Landeskunde auf geologischer Grundlage, nach 
Ergebnissen eimiger Reisen, A. PHILIPPsoN: Chiastolite in fossiliferous meta- 


morphic slates of Portugal, J. F. N. Detcapo: Striated Garnet from Buektield, 


Maine, W.S. BAYLEY, 79.—Blowpipe Analysis, J. LANDAUER, 80. 


Miscellaneous Scientific Intelligence.—The Great Earthquake of Japan, 1891, Je 


Minne aud W. K. Burton, 80.—Coneress of Mathematicians and Astronomers 
American Association, 81. 


Chas. D. Walcott, 
U.S. Geol. Survey. 


| “sablished by BENYANIN SILLIMAN in 1918 
TH # , 
AME R IOAN 
JOURN AL OF SCIEN CE. 


EDITORS | 
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ASSOCIATE EDITORS 
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AND JOHN TROWBRIDGE, OF CAMBRIDGE. 


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VOL. MEL: —[WHOLE NUMBER, eed i. 
~ No. 960.—AUGUST, 1892. 


WITH PLATES’ I-V. 


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1892. 


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we Published monthly. Six dollars per year (postage prepaid). $6.40 to foreign sub- 
_ seribers of countries in the Postal Union. Remittances should be made either by 
orders, pepistered letters, or bank checks, 


Prof. Foote has shipped us from Jtaly the following aie specimens, 
Hauerites in the gangue. The shaft from which the specimens we 
has not been worked for a year, having proved unprofitable, and though very d 
is filled with poisonous gas. The owner demands a guarantee of $1,000 to re-op 
it and free it from gas without guaranteeing that any Hauerites will be foun 
Prof. Foote made two trips to the mine taking assistants to work over the dump 
and secured a number of good specimens in the gangue. He purchased all th 
single crystals to be obtained in Catania, Raldusa, and several other places, an 
offers them at the following low rates: Single perfect crystals, 10¢e. upward. 
Broken erystals and cleavages, 5c. upward. Groups of small crystals for the micro- 
scope, 10c. to 50e. Crystals i in the clay gangue, 25c. upward. sy 
From Bottino the following fine specimens were obtained and can be offered at 
exceedinely low prices: Meneghinite crystals, 5c. to50c. Meneghinite groups 
15¢, to $5.00. Heteromorphite (Feather ore) in beautiful capillary aggregations 
25¢. to $3.50; small specimens, 5c. to 25c. From the same locality the rare yariety 
of Sphalerite, called Marmadite. This variety is so distinct in compositio 
that it is more important than many species. The crystals are well formed and 
very brilliant; usually associated with Feather ore. Groups, 25c. to $2.00. saat itt 
From Cararra very beautiful specimens of the limpid quartz on the pure white 
marble that have made this locality so well known to mineralogists. Some Speci-s 
mens associated with Dolomite and other species. Specimens, 50c. to $5.00. — 
Larderellite, Bechilite, Buratite, from the original locality at Campigli, (ae 
mine haying been closed many years). : 
Sulphurs, Aragonites, Celestites, ‘Selenite crystals and Selenite oe i 
Sulphur and Aragonite crystals showing in its limpid depths call forth the 
greatest admiration. They are in every size and form and at prices from 5e. up- 
ward. We offer better specimens for 25c. than haye ever been sold for $1.00. — 
Many fine brilliant single crystals. These are rare. Faccellite, Euchlorite, 
and many other rare species from Veswuius. Pe 


ELBA MINERALS. aoe 

Brilliant Hematites and twinned Pyrites. By a recent purchase of a Tees 
collection on the Island of Elba, Prof. Foote secured some of the most beautiful 
iridescent Hematites ever seen. Also a number of rare forms and large groups. 
There are no more showy specimens of any kind than these iridescent Hematites - 
and brilliant Pyrites. 


SARDINIAN MINERALS. 


Cerussites. If anything could rival the beauty of the above it would be the 
satin white crystals of Cerussite on a dark brown stalactitic Limonite back- a 


ground. Some of these are grouped in wheat sheaf forms similar to some eile 
bites. 25¢. each and upward. 

' Phosgenites and Anglesites are among the fine minerals secured by Prof.” 
Foote during his recent trip through Sardinia. Some of the Anglesites are green 
and show a “variety of form. The lot is pronounced the finest that ever left the 
Island and as the mines are now deep, some kinds are not obtainable and all are — 
rare. Crystals on and off the gangue, 25c. and upward. Ullmannite, the Anti- 
moniate of Nickel well crystallized in groups, from $1.00 each upward, 

Breithauptite, Argentite, Harmotome, etc., ete. © 


BOLEITE. 


Prof. Foote has just purchased the entire find of this rare species. -The lot 
contains all the forms figured by Prof. EK, Mallard and H. Cumenge in their recent 
monograph describing the species, and we are able to offer a variety of crystals, 
cleavages and groups at.greatly reduced prices. Single crystals, 10¢c. upwar oe 
Twins « of both octahedrons and cubes, $1.00 to $3.00. Gangue specimens, quite 
rare, $3.00 to $15.00. a 

Catalog ue of Minerals, 128 pp. illus. b 

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Art. XI.—On the Lelations between the Surface Tensions 
of Liquids and their Chemical Constitution; by C. E. 
LINEBARGER. 


THE mathematical and physical parts of the subject of the 
surface tension of liquids have received much attention, and 
may be considered as having reached a high stage of develop- 
ment. The basis of the theory was laid by Young,* who 
regarded a liquid as bounded by a superficial film, behaving like 
a stretched membrane, and who showed that the form of the 
surface could be accounted for by taking into consideration the 
conflict between the surface tension and the other forces act- 
ing upon the liquid. This theory was elaborately worked out 
by Laplace,t Poisson,t Gauss,§ Hagen|| and many others. 
Numerous investigators have occupied themselves with the 
experimental verification of the theory and treatment and 
development of certain physical and mathematical questions 
pertaining toit.4 The bibliography relative to the phenomena 
of capillarity is very extensive; indeed, but few branches of 
physics have received more attention. 

The chemical side of the question, on the other hand, has 


* An Essay on the Cohesion of Fluids, Phil. Transactions for 1805; and Young’s 
Collected Works by Peacock, vol. i, p. 418. 


+ Sur l’action capillaire, Supplément au X livre du Traité de Mécanique Céleste. 
(1845), Paris. 

t Nouvelle theorie del’action capillaire (1831), Paris. 

$ Principia generalia theoriae figurae fluidorum in statu aequilibrii, Géttingen. 

|| Ueber die Oberflache der Flissigkeiten, Berlin Acad. (1845). 

“| For a historical sketch of the subject, see Quincke, Pogg. Ann., cv, I, and 
Maxwell, in Encyclopedia Britannica. 


AM. Jour. Sct.—TuHIRD Serius, Vout. XLIV, No. 260.—Aveust, 1892. 
6 


84 OC. EF. Linebarger—Relations between the Surface 


received comparatively little attention, although it is univer- 
sally recognized that there must be an intimate connection 
between the capillarity and chemical constitution of liquids. 
Mendeléeff* seems to have been the first to have entered this 
field of investigation, being followed a few years later by 
Wilhemy ;+ the work of Quincket on the surface tension of 
substances at their point of liquefaction should also be men- 
tioned here. Robert Schiff,$ too, has published extensive and 
valuable facts and deduced therefrom some important conclu- 
sions in this domain of research. I will not enter now into a 
review of these investigations, as they will be frequently 
referred to in discussing my results. 

Three principal methods have been employed in the deter- 
mination of the surface tension of liquids; 1°, the capillary 
tube method, consisting in observing the height to which a 
liquid rises in a capillary tube of known bore; 2°, the drop 
or bubble method, consisting in the determination of the shape, 
and size of drops or bubbles formed in various circumstances ; 
3°—the method consisting in ascertaining the force necessary 
to pull a disk of known area from the surface of a liquid. 
These methods have, indeed, been very much modified in 
individual cases, but, in general, all may be referred to one or 
another of the foregoing. The results obtained by different 
methods have been found to be quite concordant. 

Most of the determinations of surface tension have been 
made with one liquid in contact with air, the surface tension 
of which being so small, could be safely neglected. About 
the only investigations of the surface tensions of two liquids 
in contact are those of Quincke (who determined the shape of 
drops of one liquid resting in another, and the change in the 
height of a liquid in a capillary tube when subjected to the 
influence of another liquid, ete.) and of Guthrie.| These 
researches are entirely physical, chemical questions being 
hardly touched, yet as it was Guthrie’s work which induced me 
to take up this subject, and as his methods resemble mine 
closely, I will describe some of his experiments and cite some 
of his conclusions. 

From a glass ball, suspended in a funnel-shaped vessel, water 
was made to drop, the drops being caught in a graduated tube 
placed at the bottom of the vessel. Funnel and tube were. 
filled successively with air, “turpentol,”’ and benzene, and the 
flow of water so regulated that a drop fell every five seconds. 
It was found that there were required to fill the tube up toa 


* Compt. Rend.. 1, 52 and li, 97 (1860). + Pogg. Ann., cxxii, 55, (1864.) 
t Poge Ann., cxxxy, 621. (1868) and 7b. exxxviil, 141. (1869.) © 

§ Liebig’s Ann., cexxili, 47, (1884) and Gazz. chim. ital. xiv, 137, (1884.) 
|| Proc. Roy. Soe., xiii, 444 and xiv, 22. 


Tensions of Liquids and their Chemical Constitution. 85 


fixed mark, 57 drops in air, 27 in “turpentol ” and 7 in ben- 
zene. As the benzene and “turpentol” had nearly the same 
specific gravity (see Table I), it is impossible that the differ- 
ence in the size of the drops should be due to this alone. 
Guthrie also determined the weight of drops of mercury in 
various media. I give his principal results in Table I. 


TABLE I. 
Weight of drop of Weight of drop of 
Specific gravity. mercury in mercury in air. 

FaNTOD epee meen 0° 0°7654 gram. 0°7654 gram. 
Wiatersoce 22 1 0°6462 OG 9 omnes 
Glycerine__-. 1°245 Oo 7Ony 6 Ozoloilyrece 
Benzene _-_-_-. 0°864 0-360) * 075982 
“Turpentol”_ 0°863 Ort One a 0°4350 “ 


Here also, a great difference is observed in the weights of 
the drops of mercury in benzene and “turpentol ;” and, al- 
though there is not much difference in the drop-size of elye- 
erine and benzene, yet their specific gravities are far from 
being the same. . Guthrie states as one of the principal results 
of his work that “the drop-size of a liquid, which drops under 
like conditions through various media, does not depend wholly 
upon the density of the medium and consequent variation in 
the weight of the dropping liquid.” 

Evidently this behavior is due to the chemical constitution 
of the liquids examined, and the question arises, would not the 
determination of the surface tension between many other 
liquids afford valuable data in regard to their chemical consti- 
tution? The object of the present paper is to begin the answer 
to the question. It will require much work in order to find 
out what laws underlie these phenomena, and this article will 
contain but a description of the apparatus used, together with 
some indications of the direction that succeeding investigations 
should take. The results obtained with the liquids examined 
show that some importance may be attached to the thorough 
investigation of the subject. 

Experiments of this kind should be carrried out with liquids 
which are totally or nearly insoluble in one another, but it is 
difficult, if not impossible, to find liquids fulfilling those condi- 
tions. All liquids, which have a perceptible vapor tension at 
the temperature at which a determination of solubility would 
be made, must dissolve one another to some extent; for as, in 
general, every liquid has the power of absorbing to some degree 
every gas or vapor, one liquid in this case would dissolve the 
vapor of the other, and it is impossible to distinguish between 
a solution of a substance in gaseous form and its solution in 
liquid form. This is shown by the fact that, if water be 


86 OO. EB. Linebarger—Relations between the Surface 


shaken up with an ethereal oil, although the liquids are re- 
garded as insoluble in each other, yet the latter imparts its 
odor to the former. There are, however, numbers of pairs of 
liquids which are practically insoluble in each other; at least, 
we are unable by our analytical methods to detect the presence 
of one in the other—and it is the surface tension of these 
liquids that it is my purpose to investigate. 

At the surface of two absolutely insoluble liquids, there 
would reign complete repulsion between the molecules; no 
molecule of one liquid would pass beyond a definite surface con- 
centric with the surfaces of the liquids, and this surface would 
form an impenetrable barrier to molecules of each liquid. 
But in the ease of liquids which dissolve one another a little, 
complete repulsion between the molecules prevails no longer, 
but on the contrary a slight attraction, so that now a mole- 
cule of one liquid may pass into the other. This would 
continue until the “tension” of solution of each liquid was 
reached. The question arises then, whether, in searching 
for stoichiometrical relations, the superficial tensions of liquids, 
saturated with each other, or pure, be employed. Leaving the 
discussion of the question for the present, we will in this paper 
make use of those superficial tensions determined with liquids 
uncontaminated with one another. 

It is necessary in work of this kind to select one liquid as a 
standard of comparison, absolute measurements being less 
reliable than comparative. Mercury, as regards insolubility, is 
admirably adapted to the end in view, but I have not found it 
advantageous to employ it in measurements made by the 
method I adopted. I have therefore chosen water, the uni- 
versal standard, as it is insoluble in a sufficient number of 
organic compounds to receive quite an extended use. 

The method consisted in determining :—1°, the number of 
drops into which a certain volume of water divided in “ drop- 
ping down” through liquids lighter than water and in “ drop- 
ping up” through liquids heavier than water; 2°, the num- 
ber of drops of a liquid “dropping down,” if heavier than 
water, and “dropping up” if lighter, through that standard.* 

The bulb of a small pipette was so shaped and ground that 
it fitted snugly (like a stopper in a bottle) in the neck of a 
cylindrical vessel, provided at its lower end with a stop cock. 
An inch above the bulb, a second much smaller bulb was 
blown, and between it and the larger bulb as well as an inch or 
so below the latter, marks were scratched. The lower stem of 
the pipette was bent out so as to run down close to the side of 
the cylindrical vessel nearly to the bottom, where it was turned 


*For an extension of the meaning of ‘ drop,” I refer to Guthrie’s work (loc. 
cit.) 


Tensions of Liquids and their Chemical Constitution. 87 


up through two right angles, the orifice being exactly in the 
axis of the cylinder, no matter how the pipette was inserted. 
It is of some importance that the orifice be always placed in 
such a position, that the drops may be discharged vertically. 
A second pipette with a straight stem, so as to discharge bub- 
bles downwards, was also employed. To make a determination, 
the pipette (the curved-stemmed one, if the dropping liquid is 
the lighter, and the straight-stemmed one, if the dropping 
liquid is the heavier) is filled with one of the liquids by suc- 
tion through a long rubber tube slipped over the upper end of 
the pipette and provided with a pinch cock. It is then 
inserted in the cylinder which has previously been filled with 
enough of the other liquid to stand an inch or so above the 
orifice of the pipette. The free end of the rubber tubing is 
slipped over a piece of glass tubing, so shaped that it can be 
held conveniently in the hand and closed with the thumb. 
The thumb is now kept tightly pressed over the tube, and the 
pincheock opened. A few drops fall rapidly at first, before 
the pressure becomes sufficiently reduced. By lifting the 
thumb, air may be admitted and the liquid made to drop at 
any desired rate. After a little practice, the raising of the 
thumb and the counting of the drops are done almost instine- 
tively. If the time of the growth of the drops is to be noted, 
a watch is placed at the side of the apparatus, and the falling 
of the drops made to coincide with the movements of the 
second-hand. Thisis very easily done. Suppose, for instance, 
one wants the drops to form at the rate of one a second. 
Then, by beginning to count when the second-hand crosses a 
quarter-minute mark, fifteen drops should have fallen when 
the second-hand passes the next quarter-minute mark, thirty 
drops, when it passes the next, and so on. In this way, with 
very little effort, a strict account of the time taken by the 
drops in forming can be kept. The number of drops, into 
which the volume comprised between the two marks divided 
was takenin every ease. If the last drop before the mark was 
reached did not leave the residual liquid nearly flush with the 
mark, which was generally the case, another drop was allowed 
to form, and, by observing the volume it occupied in the stem 
of the pipette, an estimation to a quarter of a drop could be 
made, which was added to the number of drops counted. 
When one determination had been made, the pipette was 
removed, wiped free from the outside liquid, refilled and again 
inserted in the cylinder. The liquids in the outside vessel are 
easily drawn off separately by means of the stop-cock. 

In regard to the accuracy of results obtained by this appa- 
ratus, it was found that determinations of drops forming at 
the same rate and dropping upwards, seldom differed, if the 


88 CO. FE. Linebarger— Relations between the Surface 


liquids were quite insoluble in each other, by more than one 
drop in a hundred. If, however, the liquids were somewhat 
soluble in each other, quite variable results would be obtained 
until the one liquid was saturated with the other. Thus water 
in dropping up through nitrobenzene which was not changed 
in three determinations gave for the first series: 1°, 136 drops 
—2°, 142 drops and 3°, 155 drops; and for the ‘second 1 
133 drops—2°, 146 drops and 3°, 161 drops. The first two 
determinations agree fairly well; they were made with water 
dropping through dry nitrobenzene. But as the nitrobenzene 
became more and more contaminated with water, the surface 
tension of the liquids changed as shown above in the number 
of drops. Three independent determinations of the number 
of drops of water saturated with nitrobenzene up through 
nitrobenzene saturated with water gave——1°, 112 drops—2°, 
110°5 drops—8°, 111 drops,—which are entirely concordant. 
This slight solubility of liquids in one another complicates mat- 
ters greatly, and renders stoichiometrical conclusions based upon 
results obtained by measurements of superficial tensions of 
liauids by the above method somewhat unreliable. Without 
doubt, however, by a further study of these phenomena, we 
shall learn how to make due allowance for such disturbing 
influences. Of the liquids which I have examined, not one, 
with the exception of nitrobenzene and bromoform, has given 
any too variable results. 

The time of the growth of drops has a little influence upon 
their size. For an elaborate investigation of the influence of 
time upon drop-size I must refer to Guthrie’s papers. In my 
experiments, it was impossible to choose a certain fixed rate 
at which all drops should form, since a large drop requires a 
longer time for formation than a small one; hence I made 
the drops form at such a rate as seemed necessary for the 
attainment of the maximum size. 

In the ease of liquids heavier than water, falling through 
water, the orifice of the pipette was wetted by the water, and 
hence the drops formed upon the inner circumference of the 
orifice, which, however, in my instrument differed very slightly 
from that of the outer. It was difficult to obtain concordant 
results in this case, since the drops | could not be prevented 
from falling by “twos” and “threes.” That is, a drop would 
commence to form slowly, when, all of a sudden, it would 
increase rapidly in size, fall off and be followed by another, 
which would, however, take a longer time for formation. 
There seems to be a sort of pull exercised by the first drop on 
the second. Sometimes two drops would issue rapidly from 
the orifice to be followed more slowly by a third. This, 
rendering the rate of formation irregular, caused the results to 


i Bi a wea 


Tensions of Liquids and their Chemical Constitution. 89 


be somewhat variable, since the first drop was evidently 
smaller than the succeeding ones. Not so much confidence, 
then, is to be placed in the results obtained by the dropping of 
heavier liquids through lighter, as of lighter up through 
heavier ones, since in ate latter case no such phenomena were 
observed. 

In the dropping of the liquids, besides the main drop, a 
much smaller secondary drop would also form almost invari- 
ably. In general, the larger the main drops,.the smaller the 
secondary drops, so that but a slight error is introduced in neg- 
lecting the latter, when the former are comparatively large. 
The formation of these secondary drops may be explained as 
follows: The main drop, just before breaking loose, is con- 
nected to the mass of the liquid by a short cylinder, the cir- 
cumference of which is that of the orifice of the ee 
When the large drop tears itself from the connecting cylinder, 
a certain impulse or shock is communicated to the latter, so 
that it is severed from the mass of liquid, and under the action 
of superficial tension and gravitation assumes a spheroidal 
form, appearing as a drop. In this paper, I have not attempted 
to make any corrections for these secondary drops, although, 
without doubt, their appearance is intimately connected with 
the superficial tension of the liquid in question. 

When water was dropped down through other liquids, it 
would run up around the orifice of the pipette so that the 
drops were larger than they should be, and consequently the 
results were quite variable. This was prevented by the fol- 
lowing simple device. A test tube just small enough to enter 
the outer vessel of the dropping apparatus was cut off so as to 
form a tube open at both ends about two inches long. In one 
end was fitted a cork through which a hole was pier ced so that 
the stem of the pipette could be thrust through it. In the 
other end was set a thin ring of cork made by cutting a cross- 
section of a good soft cork and filing it out. This: ring was 
cut into four times so as to form four shallow clefts situated 
90° apart. In these clefts were inserted fine-spun threads of 
glass, so that they crossed at the center of the ring. The 
orifice of the pipette was slioved down close enough to the inter- 
section of the glass threads that a drop, when nearly half formed 
would touch it. The drop then, instead of running up the 
sides of the pipette would be confined to the orifice, the 
erossed threads serving as a support for the drop during its 
formation. With this little device, the determinations were 
entirely concordant. 

We will first take up the discussion of the results obtained 
with liquids lighter than water. These were all hydrocarbons 
of the benzene series from the establishment of Kahlbaum 


90 C. E. Linebarger—Relations between the Surface 


labelled chemically pure. I made no special tests for their 
purity, as for my purpose they might be considered pure 
enough. 

The results are given in Table I. In the first column are 
given the names, in the second the formule of the substances, 
while in the third are recorded their densities at 20° as found 
in the literature. The fourth column contains the weights in 
grams of drops of the respective hydrocarbons in water, and 
the fifth the weights of drops of water in the hydrocar bons. 

I have not calculated the surface tension, as I did not know 
the radius of the orifice of the pipette; as it deals here of 
relative rather than absolute values, that is of little moment. 


TABLE II. 

IL. 106, IQOE Vis Vv. 
Benzene C,H, 0-879 0:0405 0°1932 
Toluene Cite Cas 0°865  0:0403 — 0°1920 
o-xylene CA es (OH a2 0°75 0:0405 0:2010 
m-xylene CE (CHE) ealc3 0°87 0°0406 071910 
p-xylene C,H,(CH,),°1°4 0°862 0:0318 01579 
Cumene C,H, -CH(CH,).. 0°87 0°0262 0712638 
Fseudocumene’ «© El (CM). 34) 0-86 00314 0°1536 
Ethylbenzene ChE Car 0°866 00178 0°0826 
Mesitylene Ci A(CHE) e335 00141 0°0725 


We notice first that the determinations of the size of the 
drops of the hydrocarbons in water and of water in the hydro- 
carbons give relatively the same results. If the numbers in 
the fourth column be multiplied by jwe, the numbers in the 
fifth column are approximately obtained. This shows that the 
two methods give strictly comparable results. 

The weights of the drops of benzene, toluene, o-xylene and 
m-xylene in water, as well as the weights of water-drops in 
them, are the same, if due allowance be made for unavoidable 
errors of observation. The superficial tensions of these organic 
liquids in contact with water have then equal values. In pas- 
sing to p-xylene, there is a considerable decrease in the weights 
of the drops. This is evidently due to the para-position of one 
of the methyl groups, for pseudocumene, which contains a 
meta- as well as para-methyl group, has the same drop-size 
as p-xylene. While the introduction of a meta-methyl group 
in benzene derivatives seems without influence upon the super- 
ficial tension, the introduction of a para-methyl group exer- 
cises, on the contrary, a decided influence. Yet three meta- 
methyl groups, as in mesitylene, cause the surface tension to 
decrease greatly Again it is to be observed how different are 
the drop-sizes in the case of toluene or methyl-benzene and 
ethyl-benzene. Cumene or isopropylbenzene also has a sur- 


Tensions of Liquids and their Chemical Constitution. 91 


face tension greater than that of ethylbenzene, but less than 
that of toluene. 

The laws which underlie these phenomena can be discovered 
only when the data are much more numerous, although with 
the above liquids important hints are given as to how those 
laws will be stated. We find further that the specific gravi- 
ties of these hydrocarbons have but little, if any, influence 
upon their surface tensions. True, the differences of density 
are slight, butit is seen that benzene with the greatest and 
o-xylene with the least density have the same drop-size. And 
again, the weights of the drops of toluene and ethylbenzene, 
liquids of almost the same specific gravity, are widely different. 
Guthrie’s first law, as stated above, seems to be verified by 
these facts. 

Of the few liquids heavier than water which I examined, 
the majority have a similar constitution. These were all care- 
fully purified and only portions boiling within a fraction of a 
degree taken. The results of the determinations are given in 
Table III., where Column I, gives the name and Col. LI, the for- 
mula of the liquids. The specitic gravities at 0° for the most 
part are entered in Col. III, and the weights of drops of water 
in the organic liquids in Ool. IV. Cols. V and VI give the 
weights of the drops of the liquids into water, orifices of dif- 
ferent sizes being used. 


TABLE III. 
J, It; INok IV. Ne WAL 

Nitrobenzene CAEN OD 2 0°0518 0:0328 

Carbon disulphide CS, 1:29 0:0667 0:0384 00461 
Amyl bromide Chee Br 1°28 0°0666 0:0382 0:0460 
Ethyl bromide C,H,Br 1°47 0°0286 0°0182 0:0221 
Benzene bromide  OC,H,. Br 1517 0:0283 0:0237 00280 
Chlorotorm CHCl, 152 0°6229 0:0278 0-03862 
Ethylene bromide C,H,Br, 2718 0°0106 00137 0°0183 
Bromoform CHBr 2°83 0:0069 0°0176 


If the numbers in Cols. V and VI, be plotted as ordinates 
and the corresponding densities as abscissas, the resulting curves 
will be seen to be parallel, showing similarity, as might be ex- 
pected, in the results obtained with different sized orifices. 

Regarding Col. II, we see that carbon disulphide and amyl 
bromide, liquids of the same specific gravity, have the same 
drop-size, while benzene bromide and chloroform, also liquids 
of about the same density, have quite different drop-sizes. A 
difference in the chemical constitution of these last two bodies 
may explain their difference in surface tension; we see also 
that, although the density of nitrobenzene is less than that of 
amyl bromide and carbon disulphide, its drop-size is not 
greater. 


92 W. Lindgren—Gold Deposit at Pine Hill, Cal. 


The influence of the specific gravity in the case of liquids 
heavier than wateris much more marked than in the ease of 
those lighter than it. Thus the table shows that with the ex- 
ception of the benzene derivatives, the drop-sizes diminish 
quite regularly, as the specific gravities increase. The anomaly 
in the behavior of the benzene molecule is undoubtedly due to 
its constitution. 

The foregoing work was performed with the purpose of 
developing and testing methods, rather than that of accumula- 
ting data; it is to be regarded as a series of “orientation” ex- 
periments, which have shown in what direction it is best 
to continue. Investigations of this sort will certainly throw a 
much clearer light upon the nature and workings of the molec- 
ular forces, a knowledge of which is of the greatest importance. 

Chicago, Ill. 


> 


Art. XIL.—The Gold Deposit at Pine Hill, California; 
by WALDEMAR LINDGREN. 


General Type.—Veins and seams of barite, carrying gold 
and silver, distributed through a kaolinized zone in diabase 
and diabase porphyrite. : 


The auriferous deposits of California have, as well known, 
two principal modes of occurrence : Secondary as gold-bearing 
gravels and sands of Tertiary or Pleistocene age, and primary 
as fissure veins, largely of late Mesozoic age. The latter occur 
in great variety of formations, but on the whole, avoid the 
large granite areas and seem to prefer the contact of sedi- 
mentary slates with eruptive, unaltered, or dynamically meta- 
morphosed masses. The form of the auriferous veins also 
varies considerably between normal, regular fissure veins and 
networks of minute irregular fractures. 

With all diversity in surroundings and form, the vein mate- 
rial or gangue and the mineral associations are simple and sub- 
ject only to rare and slight variations. The gangue is nearly 
always quartz, the mineral association native gold, sulphides of 
iron, copper, lead, and zine,—frequently also arsenical pyrites, 
rarely tellurides. Dolomite and calcite accompany the quartz 
at certain veins, but even then the quartz is usually the prinei- 
pal ore carrier.* 

*The association of native gold with calcite in Shasta County, California, has 
been noted by Mr. G. F. Becker (Statistics of the Precious Metals, Tenth Census, 


vol. xiii, p. 24), and from Trinity County, California, by Mr. J. S. Diller (this 
Journal, vol. xxxix, 1890, p. 160). 


W. Lindgren—Gold Deposit at Pine Hill, Cal. 93 


The deposit to be described here differs strangely from the 
common type. Pine Hill is situated about eleven miles south- 
southwest of Grass Valley, in Nevada County, and a few 
miles north of Bear River; it is in the lower rolling foothills 
of the Sierra, and the summit of the little knoll bearing the 
above name rises to eighteen hundred feet above the level of 
the sea; from the top an extensive and beautiful view is ob- 
tained westward over the Sacramento valley, and eastward 
toward the crest of the snowy range. 


Sketch of Pine Hill and vicinity, Nevada Co., Cal. 
Seale 2 inches = 1 mile. Contour Interval 100 feet. 


A. Diabase or Porphyrite. B. Decomposed Zone. 
C. Serpentine. D. Quartzite and Slate. 


Toward the south and west a large area extends occupied 
by massive diabases and diabase porphyrites in which aurifer- 
ous veins are but seldom met with; to the east of Pine Hill 
there is a somewhat complicated area of quartzites and clay 
slates, serpentines and gabbros sometimes dynamically metamor- 
phosed and containing a few veins of gold quartz, usually very 
capricious as to the distribution of the metal. A part of this 
area is shown on the sketch. To the northwest, beyond the 
limits of the map, there is a large and massive area of granite, 
diorite and gabbro with very few auriferons deposits. 

The diabase and diabase porphyrite which form the prevail- 
ing rock of the vicinity, are massive, fine grained and not a 
little affected by secondary processes giving rise to uralite, 
chlorite, secondary quartz, etc. The diabase porphyrites 
appear to prevail along the crest of the ridge, of which Pine 


94 W. Lindgren—Gold Deposit at Pine Hill, Cal. 


Hill forms the cumulating point. Surrounding the latter 
there is an area of intense decomposition, somewhat ill de- 
fined but approximately one mile long and from one to two 
thousand feet wide, of a very different character from the 
ordinary chloritization and uralitization. The rocks within 
this area are converted to.a soft, porous, reddish brown to 
yellowish mass, from which calcium, magnesium, iron and the 
alkali metals together with a part of the silica are removed ; 

the ultimate product of this decomposition, which I think 
should be regarded as having been effected by thermal waters, 

alkaline in character, is a soft white nearly pure kaolin* or 
hydrated silicate of aluminium. If there exists a large quan- 
tity of this pure white kaolin it could no doubt be utilized 
for keramic art; the somewhat impure substance would do 
very well for the manufacture of ordinary pottery. 

In many places the zone of decomposed and _ kaolinized 
diabase is impregnated with irregular veins and seams of barite 
or heavy spar, and with this mineral the gold is closely con- 
nected. The largest barite mass appears on the northeast side 
of the hill and about three hundred feet from the erest; a 
shaft fifty feet deep was sunk here a few years ago and some 
ore extracted. The deposit not being worked at t the time of 
my visit, the shaft was inaccessible. Tt did not appear as if a 
well defined and extensive vein of barite were present, but 
rather as a local enlargement of one of the numerous smaller 
irregular barite seams. The ore on the dump was largely 
composed of barite mixed with limonite and decomposed 
country rock. No sulphurets, but a few stains of sulphate of 
copper were noticed. Although no normal vein quartz occurs, 
there are in various places seams and smaller masses of a fine 
granular aggregate of quartzitic appearance but doubtless due 
to secondary processes. Assays were made on a series of 
specimens, both of ore and country rock, by Dr. W. H. 
Melville, in the laboratory of the U. 8. Geological Survey. 
Special precautions were taken to insure correct results and 
the exceptionally pure litharge used contained only 2 cents of 
silversto the ton. 

The assays in general show a large relative amount of silver 
—more than is usual in the gold quartz veins. The proportion 
of gold to silver by weight varies from 1:1 down to 1:5, or 
in value from 20:1 to 4:1. The metal resulting from the 
reduction of this ore would be a doré bullion similar to that 
yielded by the Bodie (Mono County) quartz veins. 

The assay of the ore from the dump, composed of barite 

*TIn a specimen of this white substance the water was determined quantita- 


tively by Dr. E. A. Schneider, who obtained almost exactly the theoretical amount 
for kaolin, viz: 13°8 per cent H.0O. 


W. Lindgren—Gold Deposit at Pine Hill, Cal. 95 


and some limonite, gave a paying amount of gold with silver 
in the proportion of 1:2 by weight; a piece of very pure 
white barite selected for the purpose, and shown under the 
microscope to contain no visible gold or sulphurets, gave the 
same amount of gold, but much more silver, the proportion 
between the two metals being 1:5. Only a part of the silver 
exists as an alloy with gold, for a pan of the ore washed out 
gave a considerable quantity of quite yellow gold in very fine 
particles; hence it may be permitted to surmise that the silver 
partly occurs as a chloride. A piece of barite with much lim- 
onite gave an exceptionally high return with but little silver, 
the proportion being 1: 1. | 

Near the crest of the hill there are several little prospect 
holes in the decomposed mass. One specimen shows a brown- 
ish to gray compact decomposed rock permeated with little 
seams of barite. This gave 0-063 oz. gold and 0°168 oz. silver 
to the ton, or $1.26 in gold and $0:16 in silver, the proportion 
in weight being about 1: 3. 

A specimen from the summit of Pine Hill is a soft erumb- 
ling mass largely composed of kaolin, pink or yellow in color 
and showing on fresh-fractured surfaces traces of the grain of 
the original rock. It was not expected that this mass would 
yield any results, but it proved to contain 0:0375 oz. gold, and 
0-075 oz. silver per ton, or respectively $0.75 in gold and $0.07 
in silver. No barite is visible in the rock, but a quantitative 
determination by Dr. E. A. Schneider showed it to contain 
0-34 per cent BaSO,,. 

At the southeast end of the decomposed area a shaft has 
been sunk to a depth of about one hundred feet, and traces of 
gold are reported to have been found. 

It is thus reasonably certain that this whole altered mass of 
diabase and porphyrite is auriferous; that barite in very vary- 
ing quantities is distributed through it, and that the quantity 
of the gold contained is approximately proportional to that of 
the barite, or, in other words, that the barite acts as the ear- 
rier of the gold. The primary mineral combination was prob- 
ably native gold, pyrite, rich silver ores, and barite. ; 

Whether the kaolinized zone is connected with large fissures, 
it is not possible to say from the present slight underground 
developments ; on the surface, at least, there are no indications 
of such a connection, yet a channel must have existed for the 
passage of the waters effecting this far-reaching alteration of 
the rocks. 

In the foothills of Yuba County and also in massive diabase 
there is a zone of extreme decomposition resembling some- 
what the one here described, but associated with a considerable 
amount of secondary, fine grained, quartzose and chalcedonic 


96 Cross and Eakins—New occurrence of Ptilolite. 


rocks. The larger part of this area carries minute quantities 
of gold and silver, the latter predominating, the ratio being 
1:6 by weight. 

Native gold is but seldom associated with barite, and only, 
as far as | am aware, in silver-gold deposits in which the 
former metal predominates. Barite is a rare mineral in Cali- 
fornia, and does not occur in the normal gold quartz veins. 
Native gold with barite is mentioned as a rare occurrence from 
southern Colorado,* and Mr. Hanks, in his description of Cali- 
fornia minerals,t refers to a specimen of barite with gold 
from the Malakoff hydraulic mine, near North Bloomfield, 
Nevada County. It may be stated in this connection that 
there is a deposit of barite in clay slates seven miles east- 
northeast of North Bloomfield and cropping out on the North 
Bloomfield ditch. J am not aware, however, that it contains 
any gold. 

Another instance of gold connected with barite is found in 
Yuba County at the junction of the North and Middle Yuba 
Rivers. A streak of chloritic schist, about twenty feet wide, 
is here impregnated with pyrite and chalcopyrite and traversed 
by seams of calcite and barite carrying the, same minerals. 
The brown surface croppings carry native gold, but it is prob- 
ably all derived from the decomposition of the pyrite. 

U. 8. Geological Survey, Washington, D. C., April, 1892. 


Art. XIIL—A new occurrence of Ptilolite; by WHITMAN 
Cross and L. G. Eakins. 


In this Journal for August, 1886, we described the first ob- 
served occurrence of a new hydrous silicate of alumina, lime 
and alkalies, to which we gave the name pézlolite. The min- 
eral was remarkable for its high percentage of silica, the analysis 
leading to the formula R’AJ,Si,,0,,.5H,O. Inasmuch as the 
polysilicie acid of this formula was elsewhere unknown, Prof. 
P. Grotht expressed the belief that the material analyzed 
maust have been contaminated with chalcedony, upon which 
the ptilolite was deposited. While it has seemed to us that the 
care exercised and the method used in the purification of the 
original ptilolite material analyzed must exciude the possibility 
of such contamination, we are glad to be able to announce a 
second occurrence of this interesting mineral the investiga- 


*See the interesting paper by Mr. R. C. Hills, ‘‘ Ore Deposits of Summit Dis- 
trict, Colorado,” Proe. Col. Scientific Soce., vol. i, p. 24. 

+ Fourth Annual Report California State Mining Bureau, p. 78. 

t Tabellarische Uebersicht der Mineralien, 2d ed., p. 149, 1889. 


Cross and Hakins—New occurrence of Ptilolite. 97 


tion of which fully confirms the earlier analysis. The work of 
L. V. Pirsson* upon mordenite has, however, fully confirmed 
the existence of silicates with the ratio between silica and 
bases which was found in the original ptilolite. 

The new occurrence of ptilolite is in Custer County, Colo- 
rado, about three miles southeast of the mining town of Silver 
Cliff. The rock containing the ptilolite occupies but a few 
square feet of surface on a low ridge of rhyolitie breccia 
reaching out from the volcanic center of the Rosita Hills,t+ 
and we are indebted to Mr. Thomas Charlton of West Cliffe 
for calling our attention to the peculiar and seemingly insig- 
nificant occurrence. The rock is a dull green felsitic mass 
containing many nearly round vesicles most of which are less 
than 5™™ in diameter while a few are somewhat larger. They 
occupy about one-third of the rock. The dull green mass 
proves on microscopical examination to bea completely devitri- 
fied pitchstone, and it is probable that this vesicular rock is a 
remnant of the upper portion of a rhyolite flow seen at a lower 
level near by, though the connection is covered by ‘wash ” 
and soil. The rock contains few phenocrysts of feldspar, but a 
fluidal structure curving about the vesicles is distinct. | Devit- 
rification proceeded from pearlitic cracks. 

The vesicles of the rock have very smooth walls and most 
of them have a thin crumbling lining of a pale yellowish or 
white substance. A few cavities contain a shell of pale bluish 
glistening quartz crystals and some are entirely filled by this 
mineral. More abundant than the quartz is a colorless or pale 
blue mineral in minute thin tablets which are often grouped in 
sheaves or bundles. This mineral was identified as barite by 
chemical analysis. 

Nearly all the vesicles contain a white mineral in extremely ' 
minute needles which form a loose, felt-like mass. Usually 
they fill the cavity and with a curved dissecting needle one can 
often remove a little white ball of the substance, apparently 
perfectly pure. The strong resemblance of this mineral to 
the ptilolite of Green Mountain was evident at first glance. 

Microscopical study of the needles shows that they are trans- 
parent, colorless, seldom more than :005™™ and often less than 
‘001"™ in thickness. Only when a number of the needles are 
arranged in parallel position in a bundle do they perceptibly 
affect polarized light. In such cases they extinguish + to the 
length axis, and by the aid of the quartz plate a negative opti- 
cal character can be made out. 


*On Mordenite, this Journal, vol. xl, p. 232, 1890. 
+ The geology of this region will be described in a forthcoming monograph of 
the U. S. Geological Survey. <A geological sketch of the Rosita Hills, by Whit- 


man Cross, was published in the Proceedings of the Colorado Scientific Society 
for 1890, p. 269. 


98 Cross and Eakins 


New occurrence of Ptilolite. 


The obtaining of material for chemical analysis was in this 
case even more difficult than with the original ptilolite. About 
six cubic feet of the rock was broken up and the tufts and 
balls of the downy mineral removed with a curved needle. 
After several days work with an assistant an amount was 
obtained which on final purification gave a trifle over half a 
gram of pure material. ‘This final purification, as in the case 
of the original ptilolite, was made by stirring the mineral in 
water, breaking up the felt-like aggregates as far as possible, 
allowing the heavier portion to settle, and pouring off; this 
operation being repeated upon the residue until most of the 
ptilolite was washed out. The collected washings were allowed 


to settle over night, the bulk of the water syphoned off, and 


the stirring and pouring off repeated until a product was 
obtained in-which no gritty substance whatever could be de- 
tected on careful testing with the rounded end of a glass rod. 
The material so obtained, after drying on the water bath, was 
left loosely covered, exposed to the air for several days. Dried 
for eight days over sulphuric acid it lost 3-84 per cent, all of 
which was regained in twenty-four hours in the air, and in this 
condition it was analyzed. Like the original mineral this new 
ptilolite is but very slightly attacked by hydrochloric¢ acid, 
and the prolonged action of hot concentrated sulphuric acid is 
required for complete decomposition. 
Analysis and ratios (Analyst, L. G. Eakins) : 


SiOMeeeepiar was 67°83 Tele 2 Oya 
PAULO eye eee gee 11°44 12 1:0 
(ORO) see ee eee aiesK0) 059 ) 

KOK nena 0°64 007 109 ‘98 

Na Oo ce eee 2-63 043 | i 

SO penis fe ee 13:44 747 6°67 

99°28 
The water was fractionated as follows: 

PACE MLN Opp cris tat nek Cro ae tem 2°62 301 1°79 
TRO gaek ain Peeeeioe tir op aese esi! ‘073 *65 
3) QS poms oe genta Testu 5°41 301 2°69 

TREO KERR S Be es Be Bx7I1(0) 172 1°54 

; 13°44 
Loss over H,SO,--.--- 3°84 213 ‘190 


For comparison with the above, the analyses and ratios of 
the original ptilolite and of mordenite are appended : 


Cross and Eakins—New occurrence of Ptilolite. 9Y 


Ptilolite, Green Mt., Colo. Mordenite (L. V. Pirsson) 
SiO, sees OS) 10°06 SiO a2 66°40 9°88 
OR eee 5 1-90 1:00 ALO Lia 1-00 
CaO E22) 3587, HelOR 3 0;5178\ 
REO 22. | 2:88 96 CaO.) 1-949) 
Na Onl. 0:77 MgO... 017 | ae 
H,O aes ee 10°18 4°86 KOn 3°58 | 
NEOUS Ct") 
99°90 H,O Leos esl 6°60 
99°41 


The empirical formula derived from the analysis of the new 
ptilolite is: R’A1,Si,,0,,+6%H,O, which it will be noticed is 
the same as that of mordenite, but as Pirsson has already 
pointed out (loc. cit.), the two minerals are physically very 
- unlike. 

The two ptilolites themselves are entirely similar both in 
their manner of occurrence and in their physical properties. 
In chemical composition the only difference is that the new 
mineral contains 3°26 per cent more water than the old, witha 
proportional reduction of the other constituents ; the molecular 
proportions of silica and bases being the same in both occur- 
rences. 

This excess of water may possibly be accounted for by the 
different conditions under which the two minerals were anal- 
yzed. The original analysis was made in Denver, the present 
one in Washington, that is, one in a very dry, the other in a 
very damp climate. Both minerals were air dried, and as both 
evidently hold a considerable part of the water very loosely, it 
seems not unreasonable to suggest that the dry Denver atmo- 
sphere may have had sufficient desiccating power to remove 
part of the water from the mineral analyzed there. In fact, 
on account of this atmospheric difference, water determinations 
in the two minerals, especially at low and medium tempera- 
tures would hardly be directly comparable, since it is now 
recognized that at a given temperature the relative humidity 
of the surrounding atmosphere may markedly influence not 
merely the rate, but also the total amount, of loss on drying. 

The fractional determinations in the new ptilolite show that 
3°10 per cent of the water is stable at 300° C., so that this may 
be basic. In the original material no such line of demarkation 
in the water was detected, although it was thought then that 
sufficient care was used, but one important factor was not then 
so well recognized as it is now, namely, the element of time in 
drying minerals of this type, and it may be that time enough 
was not given at each temperature before increasing it. The 


Am. Jour. Sc1.—Tsirp SERIES, Vou. XLIV, No. 260.—AveGust, 1892. 
7 


100 = Cross and Eakins—New occurrence of Ptilolite. 


fact, however, that a comparatively high temperature was 
found necessary for the total expulsion of the water, would 
render it easy to admit the possible basicity of part of it in 
ease other considerations made such an admission advisable in 
order to construct a rational formula for the mineral. 

In mordenite no attempt seems to have been made to frac- 
tionate the water, except to determine the loss (3°6 per cent) at 
100°, so here we have no evidence as to whether it may be 
basic in part or not. 

The fact that in the new ptilolite we have direct evidence 
that a definite portion of the water may be basic, and that no 
good ground against such an assumption exists in the analysis 
of the original mineral, makes it necessary to carefully con- 
sider this point in any attempt to theorize upon the structure 
of the ptilolite molecule. Prof. Clarke has kindly written a 
note on the theoretical formula of ptilolite and of the allied 
mordenite, which appears in the succeeding pages. 

In view of their similar mode of occurrence, of their identi- 
cal physical properties, of their exact chemical agreement 
except as to water, and of the considerations concerning the 
water presented above, there can be no question but that these 
two downy minerals belong to one and the same species— 
ptilolite. 

In comparing the analyses of mordenite and the two ptilo- 
lites a great variation in the amounts of lime, soda and potash 
is noticeable. In mordenite the molecular ratio is CaO: K,O: 
Na,O =1:1:1; but no simple ratio exists in ptilolite. 

The Green Mountain mineral is relatively poor in soda, the 
Silver Cliff mineral in potash, and the mordenite in lime, facts 
which seem very strange when we consider the rocks in which 
the minerals oceur. Mordenite occurs in a basalt, but is richest 
in potash and poorest in lime; the original ptilolite oceurs in 
an andesite of medium composition and is poorest in soda; and 
the new mineral occurs in a devitrified pitchstone and is poorest 
in potash. The last instance is most remarkable, for the piteh- 
stones of the region about are usually rich in potash and con- 
tain but very small amounts of lime. Analysis of the greenish 
felsitic mass in which the ptilolite occurs shows, however, that 
the entire rock has in this case undergone a decomposition 
which brings it to a constitution similar to that of ptilolite. 
The lime, at least, of this ptilolite was not derived from the 
surrounding rock, unless secondarily. The analysis of the 
rock containing the ptilolite of Silver Cliff is as follows 
(Analyst, L. G. Eakins) : : 


Clarke— Constitution of Ptilolite and Mordenite. 101 


SO Meee eee ey ae 65°67 
OR Bie Tien Ma! 13°48 
Bel @ ima pie Ciba iat 1°51 
Min Oieeteerte: bar) Wake tr 
BEEK Se fal bh 2 ie em 32 
Ca Oar is ere Pee 2°41 
IUCR Cs aL rae 31 
Ope ee ee 2°42 
INICIO) xssiusraten poi ie Ged ae 1°52 
SO meee Ge aa 28 
A Oe ee ae tr 
EIKO) eb ee 12°97 
100°19 


APPENDIX.—Wote on the Constitution of Ptilolite and 
Mordenite; by F. W. CLARKE. 


THE data given in the foregoing paper by Cross and Eakins, 
especially as regards the dehydration of ptilolite, lead to quite 
simple formulee for the three minerals under discussion. The 
moment that we recognize the fact that part of the water in 
each mineral may be basic, the apparent anomalies disappear ; 
and the compounds reduce at once to similar salts of the acid 
H,Si,0., which acid is well known in the species petalite and 
milarite. Both ptilolite and mordenite become simply repre- 
sentable by the general formula 

Al,(Si,O,),R’, +nAq. 
the only serious uncertainties being in respect to the hydra- 
tion. 

In brief, the following salts appear to be represented in the 
three minerals, commingled in simple ratios : 


il Al,(Si,0,),CaH, .3 aq. 
2 Al, (Si,O,),CaH, .6 aq. 
3. AlA(S1,0)) KC ES 6) aq: 
4, Al, (Si,0,),.Na,H,. 6 aq. 


Three of these are entirely alike in type: but the first, con- 
taining only half the normal quantity of crystalline water, is 
assumed in order to account for the low hydration of the orig- 
inal, Green Mt. ptilolite. Upon this basis the three minerals 
investigated may be assigned the following theoretical compo- 
sitions: 


Ptilolite, Green Mt., molecules 1 and 3, in ratio of 3:2 
‘s Silver Cliff ce PP MEIN ACA t G TBA 
Mordenite, se De San Aevnnar es Selene nT 


102. = Clarke—Constitution of Ptilolite and Mordenite. 


Reducing soda to potash in the Green Mt. ptilolite, and 
potash to its equivalent of soda in the Silver Cliff minerals, 
and recalculating to 100 per cent, we get a fair comparison 
between the actual analyses and theory. 


Ptilolite. 
Green Mt. Silver Cliff. 
Found. Cale. Found. Cale. 
Si0, 70°15 69°22 68°45 67°64 
Al,O, 11°86 Wale 7 11°55 IL ly) 
CaO 3°86 3°88 3°35 3°16 
KEO 3°98 4°34 neue A ee 
Na,O mets epee) 3°09 3°49 
H,O 10°15 10°79 13°56 Ara: 
100°00 100°00 100°00 100°00 


In mordenite, reducing Fe,O, to Al,O, and MgO to CaO, 


the comparison comes out as follows: 


Found. Cale. 

S10, 66°88 66°77 
Al,O, 11°62 TI be3355 
CaO PONT 12017 
Kee 3°62 3°49 
Na,O 2°29 2°30 
H,O 13°42 14°02 
100°00 100:00 


Considering the scarcity of material, and the difficulties 
attending its purification, these agreements are in the main 
satisfactory. In the water determinations, however, there is 
an uncertainty. In the theoretical composition assigned to the 
Silver Cliff ptilolite, one seventh of the water, a trifle under 
two per cent, is basic. But 3°10 per cent were found to be 
stable at 300°. What weight can be assigned to this discrep- 
ancy is not yet determinable, but it can hardly be regarded as 
an insuperable objection to the proposed formule. The 
general character of the salts, their essential types, seems to be 
fairly well established. 


RL. B. Riggs—Separation of Magnesium Chloride, ete. 103 


Art. XIV.—The separation of Magnesium Chloride from 
the Chlorides of Sodium and Potassium by means of Amyl 
Alcohol ; by R. B. Riaes. 


TuHis separation depends on the insolubility of the chlorides 
of sodium and potassium and the solubility of magnesium 
chloride in amyl alcohol. That the alkaline chlorides are in- 
soluble in this reagent has already been shown by Gooch in his 
paper* on the separation of sodium and potassium from lithium 
by the action of amyl alcohol on their chlorides. In the same 
paper attention is also called to the solubility of anhydrous 
magnesium chloride. The difficulty, if there be any, les in 
dehydrating this chloride. Attempts to dehydrate magnesium 
chloride by direct heat result in a more or less complete de- 
composition. This is also found to be the case where the salt, 
in a solution containing no free acid, is rendered anhydrous by 
means of boiling amyl alcohol. The amount decomposed, in 
this latter case, is however relatively small. The decomposi- 
tion products are the oxide and hydrochloric acid. It is there- 
fore necessary either to introduce conditions which will pre- 
vent such decomposition or to find a means of redissolving any 
oxide that may be formed. The use of hydrochloric acid gas 
was deemed impracticable. To use the acid solution was 
regarded as objectionablet because, in so doing, water, the 
very substance to be driven out, would be brought into the 
solution. Experiments were made in which, after the water 
of the maguesium chloride solution had been nearly or quite 
expelled by boiling with amyl alcohol, a few drops of benzyl 
chloride were added and the dehydration completed. The 
salt dissolved without leaving a residue. So little benzyl 
chloride was used that it did not seem probable that its use 
could materially affect the solubility of the chlorides of potas- 
sium and sodium. Working on this supposition a series of 
separations were made the results of which are given below. 

Standardized solutions of the several salts were used. The 
solution of magnesium chloride was prepared from the carbo- 
nate, which had been twice precipitated from moderately 
strong solutions of the chloride. The chloride thus made was 
free from alkalies and wholly soluble in amyl alcohol. The 
strength of this solution was found by treating weighed por- 


* Am. Chem. Jour., vol. ix, p. 33. 
+ This objection was afterwards found to be groundless. 


104 R. B. Riggs—Separation of Magnesium Chloride 


tions with sulphuric acid in excess, evaporating, igniting and 
weighing as sulphate.* 

The potassium chloride was obtained from the chlorate. 
The chloride of sodium was prepared from sodium hydrate 
(obtained from sodium) and further purified by precipitation 
by hydrochloric acid. 

Both solutions were standardized by evaporating weighed 
portions to dryness, drying at about 300° C. and weighing. 

The solutions, thus standardized, were found to contain 
respectively 0°5293 grm. NaCl, 0°5412 grm. KCl and the equiv- 
alent of 04146 grm. MgO to the 100 grams. 

Three series of separations, containing severally mixtures ot 
magnesium chloride and one or the other or both of the alka- 
line chlorides, were made. The solutions were evaporated 
nearly to dryness. The residue, if any, was taken up with the 
smallest possible quantity of water and a few drops of hydro- 
chlorie acid. 380-40° of amyl alcohol were then added and 
the water was expelled by bringing the alcohol to the boiling 
(128°-130° C.) Eight or ten drops of benzyl chloride were 
added and the solution was evaporated to about 10°. A per- 
forated crucible, an asbestus felt and pressure were used in 
filtering. The filtrate was transferred to a weighed platinum 
dish and the alcohol driven off by evaporation on a water bath. 
As soon as the solution became viscous water was added and 
the evaporation repeated. The residue was finally taken up 
with water and sulphuric acid was added in slight excess. 
This solution was evaporated to dryness and the residue ignited 
and weighed as sulphate. The amyl alcohol precipitate was 
dissolved and transferred to a weighed platinum dish, evapo- 
rated to dryness and heated in an air bath at a temperature of 
about 800° C. and weighed. 

The solubility corrections, as determined by Gooch,t were 
introduced, viz: For every 10% of amyl alcohol solution, ex- 
clusive of washings, 0:00051 grm. was added to the weight of 
the insoluble chlorides in case the residue was potassium chloride, 
0-00041 grm. in case it was sodium chloride and 0:00092 grm. in 
case both were present. Equivalent amounts were taken from 
the weight of the magnesium sulphate. 

The results of these separations, including determinations in 
many cases of the amounts of magnesia carried by the chloride 
precipitates, are here given. 

* Several determinations as phosphate were made which, though agreeing 
together. gave somewhat lower results than were obtained by weighing the mag- 
nesium as sulphate. This may be due to impurities in the chloride or, as is 


more probable, it may be owing to the slight solubility of the phosphate 
+ Am. Chem. Jour., vol. ix, p. 48. 


From the Chlorides of Sodium and Potassium. 


Weight of 
KCl taken. 
erm. 
(1) 0-1076 
( 2) 071084 
( 3) 0°1083 
- (4) 0-1077 
( 5) 0°1082 
( 6) 0:'LO85 
( 7) 0°1628 
( 8) 0°1630 
( 0:0109 
(10 0°0116 


Weight of 


MgO taken. 


grm. 
( 1) 0-0092 
( 2) 00094 
( 3) 0°0417 
( 4) 00421 
( 5) 0:0828 
( 6) 0:0835 
( 7) 0-1662 
( 8) 0-1661 
( 9) 0-0830 
(10) 0-0834 


Weight of 
NaCl taken. 
grm. 
(11) 0°1113 
(12) 0°1066 
(13) 0°1066 
(14) 071064 


Weight of 

MgO taken. 
grm. 

(11) 0°0836 

(12) 0°0835 

(13) 0°1663 

(14) 0°1665 


Weight of KCl 


found. 
grm. 

0'1075 
0°1080 
0°1079 
O:1071 
0:1075 
0°1079 
0°1613 
0°1614 
0:0106 
0°0114 


Weight of 


MgSO, found. 


erm, 

0°0278 
0°0275 
0°1249 
0°1264 
0°2482 
0°2509 
0°5008 
0°4986 
0°2492 
0°2494 


Weight of 


NaCl found. 


grm. 
071114 
0°1061 
0°1058 
0°1056 


Weight of 
MgSO, found. 


grm. 

0°2496 
0°2504 
0°4979 
04977 


Corr. weight 


of KCl found. 


erm. 
0°1079 
071083 
0°1083 
0°1076 
0°1080 
0°1088 
0°1622 
0°1622 
0°0110 
0:0118 


Corr. weight of 
MgSO, found. 


grm. 
0°0274 
)°0272 
071245 
0°1259 
0°2476 
0°2503 
0°4998 
0°4977 
0°2488 
0°2490 


Error in corr. 
weight of KCl 
found. 
grm. 
0°00038 + 
0:0001 — 
0°0000 
0:0001 — 
0°0002 — 
0°0002 — 
0:0006— 
0:0008 — 
0-0001 + 
0:0002 + 


105 


Weight of 
MgO found 
in KCl. 
erm. 
0°0002 
trace 
0-0001 
0:0001 
0°0002 
not det. 
0:0004 
0:0008 
not det. 
0°0001 


Error in corr. 


Corr. weight weight of MgO 


of MgO, found, 


grm, 
0°0091 
0:0091 
0°0415 
0°0420 
0°0825 
0°0834 
0°1666 
0°1659 
0°0829 
0°08380 


Error in corr. 


Corr. weight of weight of NaCl 


NaCl found. 
erm. 
0°1116 
0°1065 
0°1068 
0°1062 


found. 

grm. 
0°0003 + 
0°0001 — 
0°0003 — 
0°0002— 


found. 

erm. 
0:0001 — 
0:0003 — 
0°:0002 — 
0°0001— 
0:0003 — 
0°0001— 
0°:0004 + 
0°:0002— 
0:0001 — 
0:0004— 


Weight of 
MgO found in 
NaCl. 
erm. 
not det. 
0°0002 
trace 
0:0001 


Error in corr, 


Corr. weightof Corr. weight of weight of MgO 


MgSO, found. 


grm, 
0°2493 
0:2499 
0°4973 
0°4970 


MgO found. 
grm. 
0°0831 
0'0838 
0°1658 
0°1657 


found. 
grm. 
0°0005 — 
0:0002— 
0°0005 - 
0°:0008 — 


106 —-R. B. Riggs—Separation of Magnesium Chloride 


Error in corr. 
Weight of Corr. weight weight of Weight of 
Weight of Weight of chlorides of chlorides chlorides MgO found 


KCl taken. NaCltaken. found. found. found. in chlorides. 
grm. erm. erm. erm. erm. erm. 
(15) 0°0544 0°0529 0°1066 0°1076 0°0003 + trace 
(16) 0°0545 00531 0°1068 0°1077 0-000] + 0:0004 
(17) 0°1087 0°1063 0°2131 0°2142 0:0008— 0°:0002 
(18) 0°'1085 0°10638 0°2122 0°2134 0:0014— trace 
(19) 0°1083 0:'1064 0°2118 0:2137 0:0010 not det. 


Error in corr. 
Weight of Weight of | Corr.weightof Corr. weight of weight of MgO 


MgO taken. MgSO, found. MgSO, found. MgO found. found. 
grm. erm. erm. erm. grm. 
(15) 0:0827 0°2487 0°2475 0°0825 0°0002 — 
(16) 0:0850 0°2495 0°2484 0:0828 0°0002— 
(17) 0°1664 0°5000 0°4987 0°1662 °0°0002 — 
(18) 0°1663 0°5007 0°4995 0°1665 0°0002 + 
(19) 0°1660 0°5010 0°4987 0°1662 0°0002 + 


These results speak for themselves. It is evident that we 
have here a fairly good quantitative method. The errors are 
generally negative. This is to be expected. The large nega- 
tive errors in the weights of the insoluble chlorides, in ex- 
periments (26)—(28), are probably due to loss from manipulation. 
0-2 grams of either the insoluble chlorides or magnesia are 
perhaps too large quantities to deal with. 

10° of amyl alcohol hold 1:14 grm. of magnesium chloride 
in solution at 14° O. and 1°23 grm. at 50°C. In the majority 
of the experiments the residual volumes of alcohol were less 
than 10°. They might with safety have been further reduced, 
thus reducing the solubility corrections. 

In experiments (7), (8), (18), (14), (18) and (19) two precipi- 
tations of the insoluble chlorides were made, decanting the 
liquid, washing the residue, redissolving it and repeating the 
precipitation. The advisability of this is questionable. A 
more complete separation may be thus effected but the possi- 
bilities of loss from manipulation seem to counterbalance this 
advantage. Almost the same degree of completeness of sepa- 
ration may be attained by redissolving the precipitate with as 
little water and acid as possible and repeating the precipitation 
in the original solution. 

In dehydrating the mixed chlorides it was noticed that the 
nature of the precipitate depended much on the relative 
amounts of the magnesium and the insoluble chlorides. 
Roughly speaking, when the weight of magnesia is equal to or 
exceeds that of the insoluble chlorides, the precipitate is 
thrown out as a fine powder. When however the insoluble’ 


From the Chlorides of Sodium and Potassiwm. 107 


chlorides are greatly in excess, the tendency to obey the laws 
in accordance with which they crystallize asserts itself and we 
have a more or less coarsely granular deposit. This is espe- 
cially true in the case of sodium chloride. These facts have a 
bearing on the question of completeness of separation. 

Consider the amounts of magnesia found in the alkalies. 
They bear no relation to the amount of magnesium chlorides 
involved. It seems probable that the magnesia there found 
has been carried mechanically, and that it is not there as the 
result of decomposition. How can we better explain the 
finding of magnesia in the insoluble chlorides of experiment 
(1) where but 9 mgrm. of magnesia were involved. Here it is 
essentially the result of inclusion. 

The desirability of adding water to the amyl alcohol solution 
of magnesium chloride before completing the evaporation is to 
be emphasized. By so doing it is possible to expel the alco- 
hol so completely that even those experiments where there was 
the maximum amount of magnesia gave no trouble from ear- 
bonization. 

In adding sulphuric acid a great excess is to be avoided. In 
the above experiments about twice the amount demanded by 
theory was used. The result, in the end, is economy of time 
and less danger of loss. It is better to add sulphuric acid a 
second time and repeat the evaporation, ignition and weighing. 
In the experiments involving an amount of magnesium equiva- 
lent to 0°16 grm. of the oxide, the ignited sulphate was 
found in a few instances to increase its weight after a second 
treatment with sulphuric acid. The lesser amounts were 
almost without exception wholly converted into the sulphate 
by a single treatment. 

In the course of the work it was found that amyl alcohol 
and concentrated hydrochloric acid mix in all proportions. 
Furthermore if amyl alcohol containing but a small quantity 
of the acid be boiled down to but a small fraction of its origi- 
nal volume the residue contains chlorine in some form. 30° 
of the alcohol, to which 0:2° of concentrated hydrochloric had 
been added, having been reduced to 2° gave a decided test for 
chlorine. This suggested the possibility that the use of benzyl 
chloride was unnecessary. For, if amy! alcohol mixes with the 
concentrated acid and on being evaporated retains more or less 
of it to the last, the conditions which would prevent the de- 
composition of magnesium chloride are maintained. The 
easy solubility of the anhydrous magnesium chloride is beyond 
question. Possibly then, in the above experiments, the addi- 
tion of benzyl chloride was uncalled for as in every case 
hydrochloric acid had been previously added to the salt solu- 
tions. To decide the question a few separations were made 


108 &. B. Riggs—Separation of Magnesium Chloride, ete. 


without the benzyl chloride. 
methods were the same. 


Error in corr. 


Otherwise the conditions and 


Weight of Weight of Corr.weightof weight of KCl Weight of MgO 
KCl taken. KCl found. KCl found. found. found in KCl. 
grm. erm. grm. erm. germ, 
(20) 0:1079 0°1078 0°1082 0°00038 + trace 
(21) 0-1081 0:'1074 0'1079 0°9002 — trace 
(22) O'LO81 0°1076 0°1080 0°0001 — 0:0004 
(23) 0:1080 0°1074 01079 0°0001— 0°0008 
(24) 0°1080 071071 0°1079 0°0001 — 0:0004 
(25) 0°1076 0°1061 0°1070 0°0006— 0°0002 
Error in corr. 
Weight of Weight of Corr. weight of weightof NaCl . Weight of MgO 
NaCl taken. NaCl found, NaCl found. found. found in NaCl. 
grm. erm. grm. erm. grm. 
(26) 0°1582 0°1576 0°1583 0°0001 + trace 
(27) O'1591 0°1576 0°1582 0:0009— trace 
Error in corr. 
Weight of Weight of Corr. weight of Corr. weightof weightof MgO 
MgO taken. MgSO,found. MgSO, found. MgO found. found. 
grm. erm. grm. erm. erm. 
(20) 0:0419 0°1250 0°1245 0°0415 0:0004— 
(21) 0°0418 0°1262 0°1257 0°0419 0:0001 + 
(22) 0°0835 0°2508 0°2504 0°0835 0°0000 
(23) 0°0827 0°2498 0°2493 0:0831 0°:0004 + 
(24) 0°1665 0°4996 0°4987 0°1662 0°0003 — 
(25) 0°1667 0°5005 0°4995 0°'1665 0°0002 — 
(26) 0°1669 0°5009 0°5001 0°1667 0:0002 — 
(27) 0°1662 0°4980 0°4973 0°1658 0°0004 — 


It is evident that the benzyl chloride is not needed, further 
that its presence in the solution is harmless. 
Summary.—In separating magnesium chloride from the 


chlorides of sodium and potassium, the treatment is as follows: 
evaporate the solution nearly or quite to dryness. Dissolve 
the residue in as little water as possible and add a few drops of 
hydrochloric acid. Then add 30-40% of amyl alcohol and 
expel the water by bringing the alcohol to the boiling. Con- 
tinue the boiling until the volume of the solution is reduced 
to 10° or even considerably less. In filtering it is of great 
advantage to use a perforated crucible and an asbestus felt and 
to filter under pressure. In case the total chlorides exceed 
0-2 grm. it may be advisable to decant the liquid, wash the 
residue, redissolve and repeat the precipitation. If this be not 
done the precipitate should be redissolved with the least possi- 
ble quantity of water, a few drops of hydrochloric acid added 


J. F. Kemp—Great Shear-zone in the Adirondacks. 109 


and the precipitation repeated in the original solution. The 
filtrate is transferred to a weighed platinum dish and evapo- 
rated. Water is added before the alcohol has been expelled 
and the evaporation continued. The residue is dissolved in 
water. Sulphuric acid is added in slight excess. This solu- 
tion is evaporated to dryness, the residue ignited and weighed 
‘and the treatment with sulphuric acid is repeated. The resi- 
due of insoluble chlorides may be transferred to the weighed 
perforated crucible and dried at a temperature below their 
melting points or it may be dissolved and the solution trans- 
ferred to a weighed platinum dish, evaporated and the residue 
dried, as above, and weighed. 


Chemical Laboratory, Trinity College, 
Hartford, April, 1892. 


Art. XV.—TZhe Great Shear-zone near Avalanche Lake 
in the Adirondacks ; by J. F. Kemp. 


In July, 1889, the writer was in the region of Lake Cham- 
plain, accompanied by V. F. Marsters, while gathering notes 
upon the igneous dikes so plentiful along its shores.* Our 
attention was directed to the great trap dike which is recorded 
near Avalanche Lake in the Adirondacks, and we made a trip 
into the woods to examine it. Although, when viewed from a 
distance this rock mass appeared as an undoubted dike, yet as 
soon as it was examined in a hand specimen on the spot, it was 
pronounced at once to be no true intrusion, but to constitute a 
shear-zone,t or zone of wall rock, dynamically metamorphosed 
along a fault. Subsequent microscopic examination has cor- 
roborated this view and the case in point is an interesting and 
somewhat unique exhibition of this phenomenon. 

Avalanche Lake, a small body of water, is the very head of 
one of the feeders to the Hudson River. The pass by which 
it is reached from the north is on the watershed which diverts 
the northerly drainage into the Ausable River. The pass 
opens directly into the Lake, which is fed by springs. It isa 
narrow cafion between vertical walls of massive rock similar to 
the better known and larger Indian Pass farther west. It is 
five miles into the woods from the Adirondack Lodge. On the 


* A short digest of our results has appeared in the Transactions of the New 
York Academy of Sciences, vol. x1, p. 13, 1891. A full account will be printed 
elsewhere. 

+ For the use of this term compare Ch. Callaway, On the secondary minerals at 
shear zones, in the crystalline rocks of the Malvern Hills, Quart. J. Geol. Soc., 
Aug. 1889. 


110 J. F. Kemp—Great Shear-zone in the Adirondacks. 


west of the lake is Mt. McIntyre, on the east are Mt. Colden 
and Avalanche Mts., which two are separated by the shear- 
zone. The twin mountain is also called Mt. McMartin. The 
lake and supposed dike were early discovered and recorded in 
connection with the mining enterprise that was started at Lake 
Henderson a few miles south.* The neighboring mountains, 
Colden, McMartin, ete., were named from the promoters of 
the mining enterprise. Redfield records that both the ex- 
peditions were accompanied by one of the recently appointed 
State geologists, the first by James Hall, and the second by 
E. Emmons. 

The accompanying sketch has been traced directly from a 
photograph, taken from a point of view across the lake. It 


and the first micro-drawing were kindly made by Mr. Arthur 
Hollick. A sketch which but remotely resembles the original 
is given by Emmons in his report, p. 215 (also Ann. Rep. 1838, 
Atlas, plate 4.) The two peaks are dome-shaped knobs of 
massive rock, practically bare of vegetation and cleft from 
base to summit by the so-called dike. The latter forms a 
recess which is deeper at the lake than at the summit. At the 


* W.C. Redfield: Some account of two visits to the Mountains of Essex Co., N. 
Y., 1836-37, ete., this Journ., I, xxxiii, 301. Second Ann. Rep. N.Y. State 
Survey, 1838, p. 225; Atlas plate 1V. Emmons’s Final Rep. on the 2nd Dist., 
p. 215. 


J. F. Kemp—Great Shear-zone in the Adirondacks. 111 


lake it is 75 feet across. The walls are vertical. The so-called 
dike terminates in the lake where it is doubtless cut off by the 
eross fault that outlined the pass. It strikes N. 50-60 W. 

The general rock of the mountains is a lighter colored variety 
of the plagioclase rock which is commonly but not always cor- 
rectly called norite. Sections from the wall of the pass show 
‘coarse plagioclase in much the largest part, with which is prob- 
ably a little orthoclase. The feldspar contains many minute 
inclusions which are probably small crystals of the dark silicates 
and iron ores, exhibiting thus a common character of the feld- 
spars of rocks belonging to the gabbro family. The dark sili- 
cate is a brownish green hornblende of strong pleochroism. 
Jt occurs in shreds and irregular masses. Rather more abund- 
ant is a colorless enstatite of massive habit. The slide gives 
evidence of dynamic fractures and strains, but is far less broken 
than the rock of the shear-zone. The somewhat parallel 
arrangement of the hornblende occasions a very coarse gneissic 
structure. Under the microscope the enstatite follows a similar 
foliation. A slide from the north wall of the shear-zone ex- 
hibits much the same. It is chiefly plagioclase, with a little 
hornblende, enstatite and a little magnetite. The plagioclase 
has suffered some dynamic strains and shows faulting of twin 
lamelle. Figure 2 is a drawing with the camera lucida. The 
heavy outlines mark the crystal boundaries as seen without 
crossed nicols, after which.the twinning has been put in. The 
cleavages indicate the bisilicates, the rhombic is hornblende, 
the rectangular enstatite. : 


2 3. 


The rock of the shear-zone is dark gray in color and con- 
trasted with the walls which are lighter. It thus resembles 
trap. In the hand specimen it is seen at once to be largely 
made up of garnets and this fact cast the first doubt on its 
igneous character. It also has the appearance of a rather mas- 


112. SJ. F. Kemp—Great Shear-zone in the Adirondacks. 


sive hornblende schist or of a gneiss. Chips were taken from 
the edge of the zone and at intervals of ten feet across. They 
show some slight variations in mineralogical composition but 
they are essentially all the same rock. There is no evidence of 
the common chilling along the walls and coarser erystallization 
in the center, such as we see in dikes, but the structure is quite 
uniform throughout. The rock consists of broken irregular 
masses of plagioclase, 0-1—-0°5™™, of shreds of hypersthene, green, 
non-pleochroic, monoclinic pyroxene, pink garnet, greenish. 
brown hornblende, biotite and magnetite. The individual 
minerals are nearly in this order of abundance, but in the 
aggregate the dark silicates far surpass the feldspar. This is 
shown in fig. 8. The first four named, including plagioclase, 
are in excess. The plagioclase fr equently shows abundant evi- 
dence of crushing and indeed as fig. 8, indicates all the 
minerals are irregular and broken. Fig. 3, was drawn with a 
camera lucida. The actual field is 4"™. The impossibility of 
indicating in faithful line work the differences of the minerals 
has prompted putting initials on them. G is garnet; F, feld- 
spar; A, amphibole; H, hypersthene; B, biotite and the 
hachures are uniform for each. 

The hypersthene with pink to green pleochroism repeatedly 
passes into garnet which has a tint much like its pink. The 
same cracks run through both and it is not always possible to 
be sure when the pink shows, which mineral is present, until 
either the pleochroism or the isotropic character is proved. 
Two such are shown in fig. 3, one in the center, one in the 
lower right-hand quadrant. Pleochroie hypersthene passes in 
a similar way into non-pleochroic pyroxene. The same cleay- 
age cracks pierce both, but the extinction angles are different, 
rising in the latter to various angles from 27°-44°. In in- 
stances the hornblende seems also to have resulted from the 
hypersthene. Biotite favors the neighborhood of magnetite, 
but in fig. 38 is shown cutting a garnet mass in two. It is com- 
paratively rare. 

It may be said, therefore, that in the walls we havea coarsely 
crystalline rock, containing plagioclase, hornblende and mag- 
netite, but chiefly the first named. In the shear-zone, the dark 
silicates, hypersthene, green monoclinic pyroxene and garnet 
are collectively most abundant and with thein is considerable 
plagioclase, a little hornblende, biotite and magnetite. The 
hypersthene passes into the monoclinic pyroxene and into 
garnet both of which are considered to be derived from it. 
That the feldspar has also helped to furnish these minerals, 
probably by contributions of calcium and aluminium, is a well- 
nigh irresistible conclusion from the way it is distributed in 
isolated patches through them. Dynamic effects are abundant. 


J. F. Kemp—Great Shear-zone in the Adirondacks. 113 


The strip of the shear-zone may have been more basic origi- 
nally than the walls, and may have contained more bisilicates 
or else infiltration has rendered it more basic. Alternations 
from light to dark so-called norite are not uncommon in the 
mountains, especially where the rocks are gneissoid. Being 
dynamically affected by faulting its minerals were crushed to 
_ the shreds in which we now see them and the secondary ones 
resulted. The hypersthene is regarded as an original mineral 
because it is abundant in the less disturbed districts and is a 
more distinctively igneous mineral than those derived from it. 
It cannot be denied, however, that the sheared zone may have 
been an original dike. If so its mineralogy and structure have 
been completely reorganized. So far as observations go, dia- 
base dikes are quite plentiful in the outskirts of the mountains, 
but in neither of these characters does the shear-zone bear 
indication of ever having been diabase. The dynamic meta- 
morphism of diabase has been shown in numerous instances in 
this country and abroad to yield amphibolites. The shear-zone 
is more like an eklogite than anything else. Moreover an 
intrusion of norite as a dike is a new phenomenon for this 
region whose noritic exposures are singular massive or gneis- 
soid and send out so far as known, no dikes whatever. It is 
stated by Redfield that other and smaller dikes similar to the 
large one occur on Mt. McIntyre and frequently appear in the 
beds of brooks. He refers the lines of drainage to the greater 
relative decomposition of the supposed dikes. While no other 
one was seen by the writer which would be analogous to the 
shear zone, these smaller occurrences ought to prove to be 
diabase or some similar rock if they really are intrusions. 

A mineral aggregate similar to that of the shear-zone was met 
on Trembleau Point just south of Port Kent, and in the rail- 
ways cuts. The country rock, which contains coarse plagio- 
clase and monoclinic pyroxene as well as hypersthene, passes at 
times into dark, gneissoid bands, easily mistaken at first glance 
for trap which also seams the cuts in all directions. In the 
slides these bands are practically identical with the Avalanche 
shear-zone although at times containing more biotite. They 
make no recesses because freshly exposed. 

A case of a shear-zone was also met at Hammondville in 
the No. 7 slope of the iron mines. The workings run down 
following a bed of magnetite, for 700-800 feet. They pene- 
trate three narrow diabase dikes, by each of which the ore is 
faulted about 15 feet. The workings finally met another dark 
strip and the ore was cut off. A specimen was gathered under 
the impression that it was trap, but the section shows crushed 
remnants of the gneiss which is the wall rock. It is mostly’ 
chloritic alteration products, with shattered and strained grains 


114 Wells and Penfield—Herderite from Maine. 


of quartz, sheared micas and recognizable fragments of plagio- 
clase in the midst of decomposition material furnished by 
them. As the fault was in a different kind of rock from the 
shear-zones in norite, its products are somewhat different, and 
the great proportion of hydrated silicates give the impression 
that the shear-zones earlier described may be the result of a 
secondary metamorphism which the one at Hammondville has 
not experienced. This fault broke the ore and drill holes have 
failed to find it again. Experience in mining the adjacent 
Penfield bed has shown that the ore is cut off where the work- 
ings extend under a neighboring gully, and suggests that these 
topographical features are due in instances at least to faults. 
Such an explanation has proved true in many regions else- 
where* and will probably be applicable to some valleys of 
large size in the Adirondacks. 

Crushed strips along faults are well known in mining dis- 
tricts and have often furnished the receptacles for ores, as at 
Butte, Montana.t The drift of modern opinion refers to them 
an increasing number of so-called fissure veins. Where condi- 
tions are unfavorable for vein formation dynamic metamor- 
phism results. The work of Lossen, G. H. Williams, Teall 
and many others has shown the widespread effects of dynamic 
metamorphism, but a somewhat careful review has failed to 
reveal descriptions of any instances of such restricted effect 
and such mineralogical results as are exhibited on Avalanche 


Lake. 
Geological Laboratory, Columbia College. 


Art. XVI—On Herderite from Hebron, Maine; by H. 
L. WELLS and 8. L. PENFIELD. 


DurRiING the summer of 1891 we received from Mr. L. K. 
Stone of Paris, Maine, a small mineral, specimen for identifica- 
tion. The unknown mineral consisted of a few yellowish 
white erystals on albite. They were about 83-5™™ in length and 
their total weight probably did not exceed 2 or 3 grams. Mr. 
Stone stated that this was the only specimen of the mineral 
that had been found, and that it was discovered in 1890 at the 
pollucite locality in Hebron. 

A preliminary examination proved that the mineral was a 
phosphate, very slowly soluble in hydrochloric acid and yield- 


* J. H. Kinahan, Valleys and their Relations to Fissures, Fractures and Faults. 
London: Tribner & Co. 

+S. F. Emmons, Notes on the Geology of Butte, Trans. Inst. Min. Eng., July, 
. 1887, and Structural Relations of Ore Deposits, idem. xvi, 804. 


Wells and Penfield—Herderite from Maine. 115 


ing nearly neutral water in a closed tube. The latter reaction 
is entirely different from that of the Stoneham herderite, which 
gives off very acid water and etches the glass decidedly. 
Before the blowpipe in the platinum forceps it turned white, 
sprouted and fused at about 3 to a white enamel, coloring the 
flame very pale green. Only a few fragmentary crystals could 
‘be found which were suitable for measurement. The crystals 
had the habit shown in the accompanying figure. They were 
attached so that only the faces at one 


extremity of the macro-axis were C 
developed and were grouped in nearly 
parallel position but with the basal 


planes slightly divergent. 

The forms which were observed are: 

EuOO1,, Ol; m, 110, I; n, 331, 3 and g, 332, 3 

The basal planes were irregular and yielded no satisfactory 
reflections of the signal, while m and g were small and fre-- 
quently wanting. All of the faces except ¢ were usually 
striated. 

The measurements which were made are given below. The 
ealeulated values are derived from the axial ratio established by 
Prof. E. 8. Dana* from the Stoneham herderite. 


Calculated. 
man, 331a331= 45° 1” *45° 10/ 45° 26’ A5y 64 
Mrn, 331. 331=*102° 227 LOZ) 74 103° 247 
MAM 33 A110!) 22° 147 22° 537 22° 33/7 
mad, 331 .332= 16° 50/ LOw32¢ Nene 


Herderite ‘was not suggested to us by the preliminary exami- 
nation, and the measurements showed such a close relation to 
the angles of childrenite, that we fully expected the mineral to 
be some new variety of the latter, possibly a beryllium chil- 
drenite. It was not till the results of the quantitative analysis 
were obtained that we became aware of the true character of 
the mineral. 

The similarity in crystalline form between childrenite and 
herderite is as follows: 


Childrenite, Corresponding forms on herderite. 
b, 010, 7-% c, 001,.0 
101, 1-2 Mm, el: 
7p) Wat n, 331, 3 
s, 121, 2-2 q, 332,2 


Childrenite a: b6:c = °7780:1:°5257 
Herderite in corresponding position a: b:c = ‘1752: 1:°4929 


The axial ratio of the herderite was derived from the angles 
marked by asterisks in the above table of measurements. The 
* This Journal, III, xxvii, 229. 


AM. Jour. Sc1.—TuHiIrRD SERIES, VoL. XLIV, No. 260.—Aveust, 1892, 
8 


116 Wells and Penfield—Fflerderite from Maine. 


angle 3314331 could not be measured with certainty as the 
erystal, which was selected as best, gave double reflections from 
one of the faces. The angle 102° 22’ was selected as funda- 
mental as it was from the brightest reflection, while 103° 7’ 
agrees better with the calculated angle of herderite. 

The resemblance between the two minerals is remarkable, 
but since no chemical relation between them apparently exists, 
except that both are phosphates, the similarity in form may be 
accidental. 

The whole specimen, except two or three small crystals, 
was sacrificed for a chemical examination. The material was 
so intimately mixed with albite that the greater part of it had 
to be separated by Thoulet’s solution.. The specific gravity of 
a pure crystal as shown by the heavy solution was 2:975, that 
of the Stoneham herderite was 3-006. The material used for 
analysis varied between 2°980 and 2°853. 

A careful qualitative analysis showed the presence of beryl- 
lium oxide and the absence of all other bases except lime. 
The phosphoric acid determination was made in a separate 
portion by the molybdic acid method. The beryllium oxide 
and water were determined by methods analogous to that 
described by one of us for the analysis of herderite.* Unfor- 
tunately the determination of lime was a failure and there was 
not enough material for making a new determination. The 
fluorine was determined by weighing silicon fluoride, using a 
modification of Fresenius’ apparatus. 

The results of the analysis are as follows: 


Deducting Calculated for 


Found. Insol. CaBeOHPO3,. 
EA OEE Ss nee 40°81 43°08 44°10 
BYAO) SAe A es 6 16°18 15°53 
CaO Cheenti 2 [32°54] [34°35 | 34°78 
H,O at ees Caren 5°83 6°15 5°59 
seat be oe tee “40 42 tere 
Iimsoliecieias rere By Oe eee mips 2! 

100°17 100°18 100:°00 


The analysis shows the mineral to be a new and interesting 
variety of herderite almost free from fluorine. The result con- 
firms the idea advanced by Penfield and Harper that fluorine 
and hydroxyl are mutually replaceable in herderite, and the 
formula deduced by them for the mineral is confirmed. 

Sheffield Scientific School, March, 1892. 


* Penfield and Harper, this Journal, III, xxxii, 107. 
+ By difference. 


_— 


Gooch and Gruener—Ilodometric Determination, etc. 117 


ArT. XVIL—A method for the Lodometric Determination 
of Nitrates; by F. A. GoocH and H. W. GRUENER. 


[Contributions from the Kent Chemical Laboratory of Yale College—XV.] 


Iv has been shown by DeKoninck and Nihoul* that nitrates 
may be decomposed completely by the prolonged action of 
gaseous hydrochloric acid, and determined with accuracy by 
measuring the iodine set free when the products of decomposi- 
tion, carefully kept from atmospheric contamination, act upon 
potassium iodide. These investigators recognized the difh- 
culties attending the use of gaseous hydrochloric acid in analyt- 
ical processes, and endeavored unsuccessfully to substitute the 
strong aqueous solution for the gaseous acid. The work to be 
described in the following account was performed in the search 
for a simpler method for the iodometric determination of 
nitrates. 

According to a process recently developed in this laboratoryt+ 
chloric acid may be determined with the greatest ease. It was 
shown that in the interaction of a chlorate with potassium 
iodide, arsenic acid, and sulphuric acid, in regulated quantities 
in aqueous solution and at the boiling temperature, the first 
action of the hydriodic acid set free from the iodide by the 
sulphuric acid is upon the chloric acid, and that not until this 
action is completed is the arsenic acid attacked and reduced 
with the simultaneous liberation of a corresponding amount of 
iodine. If the arsenic acid is taken in quantity sufficient to 
insure the final decomposition of the entire amount of iodide 
present, the arsenious acid found at the end of the action is an 
exact measure of the amount of iodide which escaped the 
action of the chlorate; and, the quantity of iodide originally 
taken being known, the amount acted upon by the chlorate, 
and so the amount of the chlorate itself, becomes known. The 
arsenious acid is determinable with great accuracy iodometri- 
cally, and the chief advantage of the process lies in the fact 
that the titration is made upon the residue, and that, no collec- 
tion of the distillate being necessary, the sole apparatus em- 
ployed in the process proper is an Erlenmeyer beaker and a 
bulbed tube hung in its neck as a trap to prevent mechanical 
loss. 

This process we endeavored to apply to the determination of 
nitrates, but under none of the many variations of form and 
changes of conditions under which we tested it, were we able 
to secure complete decomposition of the nitrate without so 


* Zeitschr. fir angewandte Chemie, 1890, p. 477. 
+ Gooch and Smith, this Journal, vol. xlii, p. 220. 


118 Gooch and Gruener—Method for the 


increasing the strength of the sulphuric acid that it was acted 
upon by hydriodic acid with the consequent unregistered 
escape of products of decomposition. 

The endeavor to substitute a process essentially similar in 
principle, in which hydrochloric and antimonie acids should 
replace the sulphuric and arsenic acids proved likewise un- 
successful. 

Abandoning therefore all attempts to so arrange the process 
that the oxidizing action of the nitrate should be registered in 
the residue, search was made fora reagent which should be 
capable of inducing easy decomposition of nitrates (after the 
manner of ferrous salts in acid solution) and yet (unlike ferrous 
salts) should be so readily restored to its primitive condition 
that the products of the oxidizing action of the nitrate should 
finally pass entirely to the distillate and be registered there. 
We have found the desired combination of qualities in manga- 
nous chloride dissolved to saturation in concentrated hydro- 
chloric acid. This reagent is acted upon but slowly by nitrates 
at the ordinary temperature, but upon warming the nitrate 
begins at once to decompose with the formation of a higher 
chloride of manganese and liberation of nitric oxide. Ulti- 
mately if the heating is continued the chlorine of the higher 
chlorides is evolved and manganous chloride remains. During 
the process of heating the color of the solution passes from the 
original characteristic green through darker shades to black 
and returns by the reverse changes to the original tint. The 
decomposition of the nitrate extends under the conditions to 
the last traces, but the breaking up of the nitrates with the 
formation of the higher chloride, does not take place com- 
pletely in the presence of water amounting to more than a 
third of the volume of the solution, and an action already estab- 
lished in strong acid is reversed by the addition of a large 
amount of water. Chlorates, peroxides, and other substances. 
which liberate oxygen or chlorine when in contact with strong 
hydrochloric acid induce similar phenomena, but in the absence 
of such other substances the reaction serves to detect nitrates 
when present in fairly small amounts (perhaps one part in 
sixty thousand) as shown in the accompanying table : 


KNO; MnCl, .4H.O0 Color 

taken. in strong HCl developed. 
0°01000 grm. 10 em’ Black. 
0:00500 5 Black. 
0:00100 5 Dark brown. 
0:00050 5 Dark green. 
0:00025 5 Deepened tint. 
0°00015 5 Deepened tint. 
0:00005 5 None. 
0:00000 5 None. 


Icdometric Determination of Nitrates. LIL) 


In the first attempts to apply this reaction to the quantita- 
tive estimation of nitrates, 10 cm* of the manganous mixture, 
the pure weighed nitrate, and an excesss of potassium iodide 
were put in a tubulated retort fitted with a hollow ground stop- 
per drawn out at both ends so as to serve for the introduction 
of carbon dioxide evolved in a Kipp’s generator charged with 
marble and acid previously boiled. The neck of the retort 
passed through a rubber stopper nearly to the bottom of a side- 
neck Erlenmeyer flask, used as a receiver, in the mouth of 
which the stopper fitted tightly. The side-neck of the receiver 
was joined by a rubber connector with a bent glass tube pas- 
sing through a rubber stopper and reaching nearly to the bot- 
tom of a side-neck test tube into the mouth of which the stop- 
per was fitted. 

The first receiver contained hydrogen sodium carbonate in 
excess of the amount needed to neutralize the acid in the 
retort as it should distil over, a considerable quantity of potas- 
sium iodide (about 8 grm.) to aid in dissolving condensed 
iodine, and arsenious oxide in known amount and in excess of 
the quantity necessary to convert to hydriodie acid the free 
iodine evolved. The second smaller receiver was partly filled 
with a dilute solution of potassium iodide and hydrogen 
sodium carbonate. The current of carbon dioxide was started 
immediately upon introducing the contents of the retort, and 
the air was safely removed before the darkening of color, 
which begins to appear very soon, had spread through the 
liquid. Heat was applied, and the evolution of nitric oxide and 
later that of iodine began. The distillation was continued until 
nearly all the liquid had passed over. Finally, the contents 
of both receivers were united and titrated against decinormal 
iodine. The excess of arsenious oxide remaining unoxidized 
was taken as the measure of the iodine liberated and, accord- 
ingly, of the nitrate decomposed, upon the presumption that 
two molecules of the nitrate liberate ultimately six atoms of 
iodine according to the equation 


2HNO,+6H-I = 4H,0+2N0+3L1. 


The choice of the solution for the retention of the halogen 
evolved was dictated by the consideration, in the first place, 
that very little iodine could pass through the alkaline arsenite 
to come into contact with the rubber stopper of the receiver 
on the way to the second absorbing liquid, and, secondly, that 
higher oxides of nitrogen reformed by the action of traces of 
air possibly introduced with the carbon dioxide or imperfectly 
removed by it could not liberate iodine from an iodide in 
in alkaline solution. 


120 Gooch and Gruener—Method for the 


The iodide was introduced into the retort because having 
chosen to collect the halogen in alkaline solution it became 
necessary to take steps to break up, before it should reach the 
receiver, all nitrosy] chloride, the formation of which our ex- 
perience in former lines of work not here detailed had led us 
to expect under the circumstances. In acid solution containing 
an iodide, nitrosyl chloride liberates iodine and is registered ; 
in alkaline solution it breaks up with the formation of a 
chloride and a nitrite, the latter having no immediate action 
upon the arsenite. The results of experiments made in this 
manner are recorded in the accompanying table. 


TasuE I. 

KNO3; KI in MnCl, KNO; 

taken, retort. mixture. found. Error. 
071036 grm. O8grm. 10cm* 0:1009 grm. 0:0027 grm.— 
OPO: Orsrie Ow ORO 82s O00 02S 
01064 “ Ossie: U@ = ORO 53s OOO ss 
OsN0G/Sia es Og 200 NO OeEN@Oss}- 0:0035) 
Os0551 Os8i Ome ORO5 Sie ee 050020 aaa 


The experiments of Table II were carried out in a manner 
essentially similar to that of the experiments of Table I, 
excepting the single point that the iodine evolved in the 
process of decomposition of the nitrate was received in potas- 
sium iodide instead of in an alkaline arsenite. The contents 
of the receivers were united, made alkaline with hydrogen 
sodium carbonate, treated with an excess of decinormal arse- 
nious acid, and the unoxidized arsenious acid was determined 
by decinormal iodine. 


TasrieE II. 

KNO; KI in MnCl, KNO; 

taken. retort. mixture. found. Error. 
0°2039 grm. 16grm. 20cm* 0°2025¢rm. 0:0014 grm.— 
071060 “* Oe N@. OnlOS sews 0°0025 ‘* — 
O03 Geass Ops ass ity OS NONG ie 0:0020 “ — 
OsO13E eS Ossene ss NOW aSS OPILOOY 99 0001 
0:0521— * Os & IQ) ORORO I 0:;0000 “© — 
0202315 7S Osa Bac OO 22 iin cs 0:0008 “* — 
O:0278" Ss Oras mere 0:02.62) cs 020011) Sa 
OFOUBE™ < OnQeEss Ouves OL ON BQams 0:0004 “ — 
(OOO: Oe2iecs aeons 0:0009 “ 0;0002 “ = 


The errors of both sets of experiments, those of Table I 
and those of Table IJ, are considerable, all le in the same 
direction, and are indicative of too low registering of the 
action of the nitrate, since of the complete decomposition of 


Lodometric Determination of Nitrates. 121 


the nitrate there can be no reasonable doubt in view of the 
proved behaviour of the manganese salt toward small amounts. 
of nitrates. To us it seemed probable that the explanation of 
these results was to be sought in the failure of the titration 
in alkaline solution to indicate completely all the final products 
of the action of the nitrate. The formation, even in small 
amounts, of compounds of nitric oxide with iodine analogous to 
those which we know to be formed with bromine and chlorine, 
or the partial reoxidation of the nitric oxides by the action of 
iodine with the aid of water, an action which we recognize as 
possible under certain conditions of dilution, would account 
satisfactorily for the deficiency in the results of titration ef- 
fected in alkaline solution. Upon this presumption the simple 
and obvious modification of titrating in acid solution should cor- 
rect the error. Accordingly in the following series of experi- 
ments the plan of collecting the halogen and titrating in alkaline 
solution was abandoned, and since the addition of an iodide to 
the retort was no longer essential this practice was discon- 
tinued. The products of the action of the nitrate upon the 
manganese mixture—chlorine, nitric oxide and perhaps nitrosyl 
chloride,—were received directly in potassium iodide, and the 
iodine set free was titrated by sodium thiosulphate, itself stan- 
dardized against iodine of known value with respect to a stan- 
dard solution of decinermal arsenious oxide. 


i 


With the abandonment of the plan of putting the alkaline 
arsenite into the receiver the tendency of the iodine to pass 
onward to the second receiver is augmented and the possible 
action of the rubber stopper of the receiver becomes corre- 


122 Gooch and Gruener—Ilodometric Determination, ete. 


spondingly dangerous. We modified the apparatus, therefore, 
so that only glass should occur where by any possibility rubber 
connections might act upon the free halogen. In place of the 
ordinary retort we adopted a form of apparatus made use of 
formerly by one of us in the quantitative distillation of boric 
acid under the action of methyl aleohol—a pipette bent and 
fitted as shown in the figure. To this apparatus was sealed a 
Varrentrapp and Will nitrogen bulb, the exit tube of which 
was drawn out so that it might be pushed well within the inlet 
tube of the second receiver—a Will and Varrentrapp absorp- 
tion flask—and held in place by an outside rubber connector. 
The third receiver acts simply as a trap to exclude air from the 
absorption apparatus proper. In conducting the experiment 
the receivers were charged with solutions of potassium iodide, 
the first containing three grams, the second one gram, and the 
third only a fraction of a gram for every tenth of a gram of 
nitrate used. The first receiver was kept cool during the 
process by immersion in water. The introduction of the 
nitrate and manganous mixture following it was made easy and 
safe by applying gentle suction to the end of the absorption 
train. The current of carbon dioxide was started immediately 
after putting in the manganous mixture, and after a suitable 
time had elapsed for the removal of air heat was applied to 
the retort and the distillation was continued until nearly all the 
liquid had passed over. Finally the contents of the receivers 
were united, the washing of the bulbs was effected easily and 
expeditiously by passing the wash-water directly through retort 
and receiver (the introduction of the manganese chloride into 
the distillate being not at all prejudicial to the accuracy of the 
titration), and the estimation of free iodine made by sodium 
thiosulphate as described. The results of the experiments con- 
ducted in this manner are given in Table III. 

These results are fairly satisfactory. The mean error of the 
entire series is practically nothing. The manipulation is easy 
and rapid. 

In brief, the process which gives us these results consists in 
the distillation of the mixture of the nitrate with a saturated 
solution of crystallized manganous chloride in strong hydro- 
chloric acid in an atmosphere of carbon dioxide, the passage of 
the products of action into potassium iodide, and the titration 
of the liberated iodine by sodium thiosulphate. It is important 
to take precautions to prevent the contact of the free halogen 
with rubber stoppers or connectors, and any apparatus, suitable 
for ordinary quantitative distillation and absorption, which 
meets this condition will probably answer the requirements of 
the process. Our own preference is for the apparatus described 
and figured. 


Wheeler and Penfield—Alkaline Lodates. 123 


Taste III. 
Error . Error 
KNO3 MnCl, KNO; in terms of in terms of 
taken. mixture. found. KNOs. HNOs. 

0:2038 grm. 20 em*® 0:°2047 grm. 0:0009 grm.+ 0°0005 grm. -- 
0°2053 Do 0°2057 070004 * + 0:0003 + 
OBO: 1@ 0% OOS 5S OUMNCO Sets > Orono oe) ae 
(eisai 1@. % 0:1004 * 0:0018 “ — 00008 *“ — 

0°'1049 ‘ @)s/ 99 071049 ‘Ss OXOOCOO: OL0000-" Ss 
ONOn y= Opec OnKOQ 3 5 0:0004 “* — O-:0008 “ — 
O02 45 <2 10 ean 0°0526 ‘“ OOOO Fo AS Ooo. Se 
OO 513) << I@!.S Osama OOO 2 se Oaaxooil 09 
0°0854 * WO $6 0°0350 00004 “ — 00003 ‘ — 
OO NO 0:0230 <“ OWMOO2 2 cS OOOO 
OOO - <5 Oe OO ILOKGy 6 050004 752 0:0001) Xo — 
ROMA). <6 amates OWN EXO) OSOO OSH Sie s 10:0 0025 seat 
OeDileln = OS iy OsOUAa Si ec O;0 002 Os0 OO edna 
OLOOR32 SS R10 0:0052) << 0:0001 “ — 00001 “% — 
O20043 SF iy OS Os 004s 00004 So 020003 se 
0:0014 *§ by WS 00018 * 00.0045 ee a -1 050003) eee 

00000 ‘“ HEaase 0-0000 <6 OZ0.0008 Fe 0:0000 “ 


The titration should be completed as soon as may be after 
admitting air to the distillate in order that traces of dissolved 
nitric oxide may not be reoxidized and again react upon the 
iodide present to liberate more iodine. 


Art. X VIII.— On some Alkaline Ludates ; by H. L. WHEELER. 
With Crystallographic Notes; by 8. L. PENFIELD. 


WHILE work on the compounds of iodine trichloride with 
alkaline chlorides* was in progress in this laboratory, it was 
noticed in making KCl. Cl,I, RbCl. Ci,I and CsCl. Cl,I that 
white crystals were often formed under certain conditions. 
These compounds proved to be KC]. KIO,. HIO,, RbCl. HIO, 
and 2CsIO,.1,O,. Since they were not analogous, although 
formed under similar conditions, and since the rubidium and 
cesium salts have not been described, an investigation of them 
was undertaken. Attempts to prepare these compounds by 
other methods led to the discovery of several other iodates. 
The new compounds that have been prepared are as follows: 


‘ 


RbIO, CsIO, 

RbIO, . HIO, 20sI0, . 1,0, 
RbIO, . 2HIO, 2Cs10, . 1,0, . 2HIO, 
RbCl. HIO, CsCl. HIO, 


3RbCl. 2HIO, 


* This Journal, xliv, 42. 


124 Wheeler and Penfield—Alkaline Lodates. 


The compound which separated from the solution of the 
potassium pentahalide has already been described, but since 
this is a new method of preparation and since there are con- 
flicting statements concerning its state of hydration, it has 
been re-investigated. 

The results of the investigation of the rubidium salts show 
_that the normal iodate is the only one of the series that can 
be recrystallized unaltered from an aqueous solution. In the 
case of the cesium compounds, the normal iodate and the salt 
2CsIO, . 1,0, are not decomposed by water. The other cesium 
iodates give 2OsIO,. 1,0, when recrystallized from water and 
not the normal iodate, thus showing an interesting difference 
between the rubidium and cesium compounds. 

It is the tendency of the acid rubidium iodates to separate 
in a higher state of hydration than the corresponding cesium 
compounds. 

It is also an interesting fact that the formation of the com- 
pounds of normal chloride and iodic acid was not observed on 
mixing the constituents. In the case of rubidium, products 
were obtained which proved to be RbIO,, RbIO,. HIO, or 
RbIO,. 2HI1O, according to the concentration of the solutions 
and the excess of RbCl or HIO,. On the other hand by add- 
ing hydrochloric acid to a solution of rubidium iodate, if the 
acid is dilute RbIO,, 2HIO, is formed, if concentrated the 
iodate is completely decomposed. Similar experiments under- 
taken with cesium chloride and iodic acid, did not give the 
peculiar double compound CsCl. HIO, but resulted, in each 
case, in the formation of 2CsIO, . I,O,,. 


Method of Analysis. 


After the substances were prepared for analysis as described 
in detail beyond, the halogens were determined by first reduc- 
ing the solution of iodate with sulphur dioxide then precipi- 
tating with silver nitrate in the presence of nitric acid. This 
precipitate was then heated in a stream of chlorine, thus com- 
bining the test for chlorine and its determination in one opera- 
tion. In the filtrate from the silver precipitate the alkali 
metal was determined as sulphate after the removal of the 
excess of silver by means of hydrogen sulphide. Oxygen was 
determined in a separate portion by precipitation with silver 
sulphate, drying the precipitate at 100° and then determining 
the loss on ignition. Duplicate halogen determinations were 
then made in this residue. In the case of the compounds con- 
taining the group I,O,, where an error would be introduced 
if the oxygen was determined in this manner, the substance 
itself was ignited and the oxygen calculated from’ the loss. 


Wheeler and Penfield—Alkaline Lodates. 125 


The presence of water in these compounds was determined by 
directly weighing it in a calcium-chloride tube, the substance 
being ignited in a combustion tube containing a mixture of 
lead chromate and lead oxide. 

Normal rubidium iodate, RbIO,—This compound was 
made by adding one molecule of iodine pentoxide in either 
strong or dilute aqueous solution, to a solution of one mole- 
cule of rubidium carbonate. If the solutions are strong, the 
iodate separates as a sandy precipitate, but if they are hot and 
dilute it separates on cooling in small grains or as a crystalline 
erust. At 23° 100 parts of water dissolve 2:1 parts of the 
salt. The compound, after filtering on the pump, washing 
with a little water and drying on paper, gave the following 
results on analysis: 


Found. Calculated for RbIO3;. 
Rubidium, 3221 32°82 
Iodine, 48°50 48°75 
Oxygen, 20°59 18°43 


The salt when heated decrepitates strongly, melts, gives off 
oxygen but no iodine, and the residue is rubidium. iodide. 
Hydrochloric acid readily dissolves it in the cold to a faint 
yellow-colored solution which increases in color on standing. 
On warming, chlorine is evolved and the solution turns bright 
yellow from the formation of iodine trichloride. If boiled 
with strong hydrochloric acid, RbCl. Cll* is formed which 
separates on cooling. 

The formation of normal rubidium iodate was also observed: 
when a hot dilute aqueous solution of iodine trichloride was 
treated with rubidium carbonate. The compound thus ob- 
tained gave 48°43 per cent of iodine on analysis. Also by 
dissolving the acid iodate in a strong hot solution of rubidium 
chloride and allowing the mixture to crystallize. This was 
identified by a rubidium determination which gave 32°58 per 
cent. In general the iodates of rubidium all give this body 
when they are dissolved in hot water and the solutions left to 
erystallize. The products obtained in this manner decrepi- 
tated on heating and did not give off iodine. A rubidium 
determination in the substance obtained from RbCl. HIO, 
gave 32°76 per cent; from 3RbCI. 2HI1O,, 32°22 per cent. 

Acid rubidium iodate, LbIO,HIO,. —This was obtained by 
mixing warm solutions of one molecule of iodine pentoxide 
and two molecules of rubidium chloride. The compound 
generally separates on cooling as a heavy erystalline powder. 
It is difficultly soluble in cold water. Hot water dissolves it 
more readily and on cooling, the normal iodate separates. It 


* This Journal, xliii, 475. 


126 Wheeler and Penfield—Alkaline Iodates. 


is insoluble in alcohol. The crystals were filtered on a pump 
and washed with a little cold water and then pressed on paper. 
An analysis of these dried at 100° gave the following results, 
the oxygen being determined by difference. 


Calculated for RbIO;. HIOs. 


Rubidium, 20°13 19°58 
Iodine, 58°12 58°19 
Oxygen, 21°46 21:99 
Hydrogen, "29 "23 


The reaction which takes place in the preparation of this 
compound is probably according to the following equation : 


RbCl1+2HIO,=RbI0,. HIO, + HCl, 


The hydrochloric acid thus liberated reacts on a part of the 
iodic acid, chlorine is evolved and the solution becomes yellow. 
When heated it does not decrepitate, but melts to a yellow 
mass, gives off water, then iodine and finally froths with the 
evolution of oxygen. The residue consists of rubidium iodide. 

Diacid rubidium todate, RbLIO,. 2HIO,.—For the prepara- 
tion of this compound 5 grams of RbIO, were dissolved in 
50 ec. of water with the aid of heat, then 13 grams of iodine 
pentoxide in 50 cc. of water were added, the mixture boiled 
down to half its volume and allowed to cool. The body sepa- 
rates as a heavy crystalline powder. It is difficultly soluble in 
cold water. When dissolved in hot water and. the solution 
left to crystalline RbIO, separates. The product obtained as 
stated above was separated from the mother liquor by filtering 
on the pump, washed with a little cold water and dried at 
100°. 


Found. Calculated for RbIO;.2HIOs. 
Rubidium, 13°93 14:13 13°96 
Todine, 61°91 62°48 62°20 
Oxygen, 23°74 O35 
Hydrogen, "42 33 


This compound does not lose water at 100°. When heated 
it does not decrepitate, but melts, gives off water, then iodine 
and oxygen, leaving a residue of rubidium iodide. The com- 
pound was also obtained by adding 10 ce. of hydrochlorie acid 
sp. gr. 1-1 to 5 grams of RbIO, in 20 ce. of water. The mix- 
ture was warmed until all the RbIO, dissolved. It gave a 
faint yellow solution which slowly deepened in color. On 
standing, a well crystallized product of the compound under 
consideration was obtained containing 14°13 per cent of rubid- 
ium and 62°19 per cent of iodine. 


Wheeler and Penfield— Alkaline Lodates. 127 


The addition of a saturated solution of rubidium chloride to 
syrupy iodic acid produces a precipitate which dissolves again 
in the excess of iodic acid. When more rubidium chloride is 
added, the whole being kept over a lamp, a point is reached 
where a precipitate begins to form in the hot solution. This 
is the compound in question. It was identified by a rubidium 
and an iodine determination. This gave 14°17 per cent of 
- rubidium and 61°83 per cent of iodine. 

RbCL. HTO,.—This salt can be made by simply allowing a 
saturated solution of RbCl. Cl,I to stand for some hours, when 
large colorless prisms form, attached to the plates of RbCl. 
Cl,l. The solution, after removing the crystals, warming to 
dissolve the pentahalide and pressing chlorine in again, does 
not yield a further deposit of the substance. This is explained 
by the fact that so much hydrochloric acid is formed in the 
solution that the formation of this compound is prevented. 
The crystals remain unaltered on exposure to the air. On 
treatment with cold water they are decomposed, losing their 
luster and becoming white. The solution has an acid reaction 
towards litmus. The hot saturated solution of this compound 
gives tne normal iodate on cooling. The material for analysis 
was mechanically separated from adhering RbCl. Cl,I and 
_ dried in the air. 


Found. Calculated for RbCl. HIOs. 
Rubidium, - 28°88 28°78 
Iodine, 42°29 42°62 42°76 
Chlorine, L209) L213 11°95 
Oxygen, 16°33 16°16 
Hydrogen, "26 33 


This salt can also be prepared by adding a strong aqueous 
solution of rubidium hydrate to a strong solution of iodine 
trichloride in water. This gives at first a precipitate of the 
compound 38RbC1. 2HIO,, and the solution left at rest for a 
few days gives the large well developed crystals of RbCl. 
HIO, unmixed with RbC1.CI,I. These were identified by 
their crystalline form. 

On warming the crystals with hydrochloric acid RbCl. Cl,I 
is formed, probably according to the following equation : 


RbCl. HIO, +5HCI=RDC1. Cl,I+3H,0+Cl, 


and the RbCl. Cl,I on further heating gives RbCl. CII with 
the liberation of chlorine. When the substance is heated it 
melts, gives off water, chloride of iodine, and oxygen the 
residue consists of rubidium chloride and iodide. A deter- 
mination of the halogens in this residue gave 3°52 per cent 
of chlorine and 58°66 per cent of iodine. 


128 Wheeler and Penfield—Alkaline [odates. 


3RbCL. 2HL0,—This compound, which is analogous to the 
sodium compound 3NaCl.2NalO,.9H,O described by Ram- 
melsberg* and also to the salt 83Nal .2NaIO,.19H,O obtained 
by Pennyt or 3Nal. 2NalO,.20H,O according to Marignac,t 
except that it contains no water of crystallization, was prepared 
by two methods. It was obtained by the addition of a hot, 
strong aqueous solution of rubidium hydroxide to a strong 
solution of iodide trichloride, the latter being in excess. The 
mixture was then filtered hot and on cooling, a mass of fine 
needles separated. The mother liquor on standing yielded the 
large crystals of RbCl. HIO,. The needles are stable in the 
air and at 100°. From the hot saturated aqueous solution of 
the compound the normal iodate separates on cooling. 

The formation of this compound was also observed on add- 
ing a strong solution of rubidium carbonate to a hot saturated 
solution of RbCl. Cl,I, the latter being in excess. The color- 
less slender transparent needles thus obtained generally sepa- 
rate in groups radiating from a point on the surface of the 
yellow crystals of RbCl. Cl,I. After separating the colorless 
crystals mechanically from the pentahalide they were air-dried 
on paper and then analyzed, while the material obtained accord- 
ing to the previous method was dried at 100°. 


From RbOH From Rb.COs Calculated for 

and ICls. and RbCl. ClgI. 3RbCl. 2HIOs. 
Rubidium, 35°41 34:58 30°78 35°87 
Todine, 35°27 36:00 35°87 35°81] 35:52 
Chlorine, 14°99 14°82 15°26 15°16 14:90 
Oxygen, 13°15 13°64 13°43 
Hydrogen, "29 "30 28 


When heated, the substance does not decrepitate but melts, 
gives off chloride of iodine and the residue consists of a mix- 
ture of rubidium chloride and iodide. A sample of this resi- 
due gave on analysis 9°68 per cent of chlorine and 38-91 per 
cent of iodine. 

Normal Cesium iodate Csf£O,.—This was prepared by add- 
ing a moderately strong aqueous solution of iodic acid to a 
strong solution of cesium carbonate, care being taken to have 
the carbonate in excess. When all the iodic acid had been 
added, the solution was boiled. On cooling, a crystalline mass 
separated consisting apparently of small cubes. At 24°, 100 
parts water dissolve 2°6 parts of the salt. It is insoluble in 
alcohol. The body was prepared for analysis by filtering on 
the pump, washing with cold water and then pressing on paper 
and drying at 100°. 

* Poge. Ann, xliv, 548; exv, 584. 

+ Ann. Ch. Pharm., xxxvii, 202. + Jahresb., 1857, 124: Ann. Min., V, ix, 1. 


Wheeler and Penfield—Alkaline Iodates. 129 


Calculated for CsIO3;. 


Cesium, 43°08 43°53 43°18 
Iodine, 40°84 41°23 
Oxygen, 15°74 15°59 


This was also obtained in attempts to prepare a cesium salt 
corresponding to 83RbC]. 2HIO, by adding cesium hydrate or 
carbonate in moderately strong aqueous solution to a strong 
solution of iodine trichloride in excess, when it at once sepa- 
rated in the form of a white sandy precipitate, which under 
the microscope was seen to consist of transparent grains of 
indefinite form. Unless the iodine trichloride is nearly satu- 
rated with the carbonate, CsCl. C],I or CsCl. Cll* is obtained 
mixed with the iodate. An iodine and oxygen determination 
in the air-dried salt gave 40°55 and 40°83 per cent of iodine 
and 15°67 per cent of oxygen. When this iodate is heated it 
does not give off iodine but melts and evolves oxygen. The 
residue is ceesium iodide. 

2CsLO,. [,0,—This substance can be prepared in pure con- 
dition and in large quantity by mixing a moderately dilute 
aqueous solution of two molecules of czsium chloride with one 
molecule of iodine pentoxide dissolved in a little water. Any 
precipitate that may have been produced is dissolved by the 
aid of heat and more water if necessary. On cooling, the com- 
pound separates as a sandy powder. This can be washed with 
water or recrystallized from hot water without decomposition. 
It can also be recrystallized from dilute solutions of iodic acid. 
At 21° 100 parts of water dissolve 2°5 parts of this salt. It is 
insoluble in alcohol. The material for analysis was air-dried 
after pressing on paper. 


Found. Calculated for 2CsIO; . 1.03. 
Ceesium, 27°93 28°00 
Iodine, 53°42 53°47 
Oxygen, 18°69. 18°53 


This compound invariably separates along with the crystals 
of OsCl. Cl,I, when the latter is prepared in the absence of 
hydrochloric acid. The yield is not very large. It is thus 
obtained in the form of small rounded white nodules which on 
close inspection are seen to occur in pairs, the two nodules 
being on opposite sides of a thin layer of the pentahalide. 
They were mechanically separated from the pentahalide, no 
water being used to wash the compound when prepared for 
analysis. The following results are sufficient for its identitica- 
tion. 


* This Journal, III, xliii, 17, and xli¢, 42. 


130 Wheeler and Penfield—Alkaline Lodates. 


Osim “25 22a oe eee 29°11 
Todine: 22 22.2. 28-4520 332 eee 50-21 
Oxy Pen) j2.2n. 3 beeen e eee e 18°99 
Ghionne fee AUER al gc PE 3°24 


This compound was also obtained by the following methods. 
By mixing 6 grams of CsIO,, 20 ec. of water and 10 ce. of 
HCl sp. gr. 1:1. The mixture was boiled, it became yellow 
and chlorine was evolved. When cooled the substance sepa- 
rated as a crystalline crust. It was identified by a determina- 
tion of cesium which gave 28°40 per cent. 

The compounds 2CsIO,. I,0,.2HIO, and CsCl. HIO, give 
this body when their hot saturated solutions are cooled. A 
ceesium determination in the products thus obtained gave 27-94 
and 28°12 per cent respectively. 

When this body is treated with hydrochloric acid, sp. gr. 
1-1, the solution becomes yellow, evolves chlorine on warming, 
and when concentrated on the water bath yields on cooling 
well crystallized CsC1.ClI. Analysis gave 50°63 per cent of 
cesium chloride, calculated for CsCl . CIL 50-90 per cent. 

When heated in a closed tube it gives no sign of water, 
gives off iodine then melts with the evolution of iodine and 

oxygen. ‘The residue consists of cesium iodide. 

20sLlO,.1,0,.2HIO,—This body was obtained by adding 
5 grams of 2Cs10, . i O, to a boiling solution of 25 grams of 
iodine pentoxide in sufficient water to form a syrup. Water 
was then added and the precipitate thus produced proved to 
be the compound in question. Thus produced it separates as 
a finely divided amorphous precipitate which can be dried in 
the air or at 100° without losing water. It is difficultly solu- 
ble in water and when crystallized from an aqueous solution 
gives 2CsIO,. 1,0, An analysis of the substance dried at 100° 
gave 

Calculated for 


, Found. 203103120; . 2HIO3. 
Cesium, 19°71 20°43 
Iodine, 57°68 58°52 
Oxygen, 20°41 20°89 
Hydrogen, "12 "16 


Water determinations in samples dried in the air on paper 
gave 1:45 and 1°38 per cent; theory requires 1-44. 

When the substance is heated it gives off water and iodine, 
then oxygen, the residue consisting of ceesium iodide. 

CsCl. HIO,.—This was obtained in an attempt to increase 
the yield of 2CsIO,. 1,0, by adding a rather small quantity of 
cesium carbonate to a hot saturated solution of CsCl. Cl,I, 
when on cooling and allowing the mixture to stand, colorless, 


~~ 


Wheeler and Penfield—Alkaline Lodates. 131 


flat, transparent prisms separated on the yellow crystals of 
CsCl. Cl, previously formed. These colorless prisms were 
picked out from the solution dried on paper and separated me- 
chanically, as far as possible from any adhering CsCl. Cl,I. 
These on analysis gave the following results. 


Found. Calculated for CsCl. HIO;. 
a 
Cesium 38°09 38°60 
Iodine 36°08 36°29 36°86 
Chlorine 11°69 11°82 POs 
Oxygen 13°85 13°94 
Hydrogen 30 "29 


The erystals remain unaltered on exposure to dry air but on 
treating them with water they immediately become opaque. 
On recrystallizing from water they give 2Csl0,. 1,0, When 
the substance is heated it gives off water and iodine chloride, 
melts, and gives off oxygen, the residue consisting of chloride 
and iodide of cesium. When it is warmed with hydrochloric 
acid it undergoes the same decomposition as the correspond- 
ing rubidium compound. 

KCL. KLO,. HL0,,—This compound has Dreiouely been 
prepared by tr eating KIO, with hydrochloric acid, or a solution 
of iodine trichloride with ‘potassium hydrate or carbonate. It 
has been described by Serullas* and Rammelsbergt as anhy- 
drous and the formula 2K C1. 2KIO, . 1,0, was assigned to the 
salt. Millont from his determination of potash in this salt 
concluded that the substance contained a molecule of water, 
but he made no determination of it. Finally, Marignac§ who 
examined it more carefully, made a determination of the water 
by drying the substance at 100°, then igniting it in a tube 
with metallic copper and collecting, and weighing the water 
by means of a sulphuric acid tube. 

The compound obtained from a solution of KCl. Cl,I sepa- 
rated in shining transparent prisms, stable in the air. It con- 
tained water corresponding to the formula 2KCl. 2KIO,. 1,0, 
. H,0 or KCl. KIO,. HIO,. An analysis of the air-dried salt 
gave the following results. 

Calculated for 


Found. KCl. KIO; . KIOs. 
aso 

Potassium 16°94 16°83 16°82 
Jodine | 54°46 ! 54°66 
Chlorine eee, 7°64 
Oxygen 20°66 
Hydrogen "20 eee 

* Ann. Ch. Phys, IT, xliii, 113. + Ann. Ch. Phys, III, ix, 407. 

+ Pogg. Ann., xcvii. § Jahresb., 1856, 298. Ann. Min., V, ix, 1. 


AM. JoUR. ScIl.—THIRD SERIES, Vou. XLIV, No. 260.—AveustT, 1892. 
9 


132 Wheeler and Penfield—Alkaline Iodates. 


This compound and the one obtained by Marignae are there- 
fore identical. 

On ignition it gives off water, iodine chloride and oxygen, 
the residue consisting of potassium iodide and chloride. An 
analysis of this residue gave 2°39 per cent. chlorine and 70°87 
per cent. iodine. 

The author takes occasion here to express his obligations to 
Professor H. L. Wells for the use of the material in this in- 
vestigation and for valuable suggestions, also to Professor S. 
L. Penfield who has kindly furnished the erystallographical 
descriptions. 


Notes on the Crystalline form of RbCl. HIO, and CsCl. 
H1IO,; by 8. Li. Penfield. 


RbCl. HIO,. 


The form of RbCl. HIO, is monoclinic. The 
erystals are highly moditied, doubly termi- 
nated prisms, fig. 1. The faces gave fair reflec- 
tions and the measurements which were chosen 
as fundamental are marked by an asterisk in 
the table of angles. 

The axial ratio and forms are as follows: 


%: b: dé = 0°9830:1: 07577, B=100, 001 = 87° 56’ 


a, 100,72 |. 1, 820)4-8 . dh Ol, 1) gp lO a7 egal4oe see 

b, 010, 7-2 =m, 110, I Cx ON, let) oF 20lee =D DN ED 

c, 001, 0 n, 120, 7-2 7 I ee Foy WHR GA LS 

Measured. Calculated. Measured. Calculated. 
AC NOD AKO Sete bx GN 100) OMG S8xe 20S Sian 2iles 
xO MOO A NOM ail 1 Gia Ss) LOO 2 88h so ai 
ez OOUAMI SSosiy 13 aau, 100,111=59 57 59 38 
treats MOO A B20 ° S333 1B. SRP ile 6 np, VOM AT == 508 28530 
anim, LOO 10S 445 Fie 44295 FiNw VOU A 3 ee: 
axn, 100,120 = 62 42 Saye pag, 111.142 = 26 36 26 30 
GO M00 2 SSA 388s 8s- Crip Wikre Mz == Wi Ril ZO 
Bewiiy MOO. Wb Si ales aii a 6x fF, 001 10 = 38 26) 38 234 
CsCl. HIO,. 


The form of CsCl. HIO, is monoclinic. The erystals, from 
the one crop which was examined, were 


: about 5 mm. in length and had the 


(ee ee —a habit shown in fig. 2. They were 
we, 7m attached at one end and usually grew 


in radiating and divergent groups. The 
faces were not very perfect and only approximate measure- 


C. £. Beecher—Development of the Brachiopoda. 133 


ments could be made. Those which were chosen as funda- 
mental are 


wm, VEO ~ 110902 127 min, 110), 221242 3%” a xp, 100! x 221 49° 53” 
The axial ratio and forms are as follows: 
yi b:d¢ =0°9965:1:0°7698  8—= 100. 001—89° 534% 


a, 100, 7-7 m, 110, I d, 403, —4-1 s, 403, 4-7 p; 221, —2 
2, 001, 0 Pesos are 2030 3-7 203) Pr eo 2G3 nes 


The pyramids p and o were frequently wanting. The ortho- 
domes d, ¢, s and w were very constant in their development 
and gave iG the erystals an orthorhombic habit. Owing to the 
curved and striated character of the faces the symmetry could 
not be satistactorily determined by measurement, but the 
optical properties showed that the crystals were tr uly mono- 
clinic. In polarized light the tables show an extinction par- 
allel to the ortho- axis and in convergent light one of the 
optical axes and the acute bisectrix can be seen near the 
limits of the field. The plane of the optical axes is the clino- 
pinacoid. 

These two salts, although entirely different in erystalline 
habit, are very similar in their axial ratios. 

Sheffield Scientific School, 

April, 1892. 


Art. XIX.—Development of the Brachiopoda. Part II. 
Classification of the Stages of Growth and Decline; by 
CHARLES E. BEECHER. (With Plate I.) 


A BRIEF review of the known embryology of the Brachi-. 
opoda is desirable, in order to account for some of the differ- 
ences presented by adult forms in the several divisions of the 
class. This knowledge is far from complete, and is confined 
to a few species, but much of interest bearing on the later 
development of the organism may be obtained. 

The important memoirs of Morse,*®™” Kovalevski,® 
‘Lacaze-Duthiers,"" and Shipley,” contain nearly all that is 
known regarding the early embryology of brachiopods. The 
genera included in the works of these authors comprise 
Cistella, Terebratulina, Liothyrina, and Lacazella. Later 
larval stages of the genus Glottidia have been fully described 
by Brooks.* Miiller,” also, has given a description and figures 


*The works referred to by numbers are cited in full in the list appended to 
this article. 


134 8 C. EL Beecher—Development of the Brachiopoda. 


of a larval form doubtfully referred to Discinisca. The results 
of these observers must at present be taken without reserva- 
tion, and are thus made use of in the present paper. 

Something is known, therefore, of the early stages in each 
of the four groups or orders proposed by the writer.’ The 
Atremata, Neotremata, and Protremata are represented by a 
single genus only in each ; Glottidia, Discinisca, and Lacazella, 
respectively ; and the Telotremata, by Cistella, Terebratulina, 
and Liothyrina. Were Glottidia and Discinisca as well known 
as Cistella, Terebratulina, and Lacazella, some comparisons 
could undoubtedly be made which would enlighten many ob- 
scure points of anatomy and morphology, as well as give 
clearer insight into the history and origin of each group. 

Cistella and Terebratulina are taken as standards of the 
embryological development on account of the completeness 
with which they have been studied, and because their points 
of difference are not great. Lacazella shows such peculiar 
features, that its history must be discussed separately. The 
nepionic Glottidia and Discinisca, too, present characters 
which evidently had an early history somewhat different from 
Cistella or Terebratulina. 


In taking up the review of the observed stages of growth, 
an attempt will be made to fix their limitations. To this end 
the admirable nomenclature proposed by Hyatt®” is here 
adopted, as it is more convenient and of wider application and 
significance than the terms heretofore used. Thus far this 
system has been employed principally in studies relating to the 
mollusea, and its application to the Brachiopoda will neces- 
sarily require some illustration and explanation. In the 
preface to ‘“‘Genesis of the Arietide,” Hyatt has presented a 
summary of the theoretical opinions resulting mainly from his 
' studies in the Cephalopoda. It is believed that nearly the 
same ground may be covered in the Brachiopoda, and thus the 
truth of these deductions will receive further evidence from 
another class of organisms. 


Embryonic stages. 


The true embryonic stages are clas sified by Hyatt as Prot- 
embryo, Mesembr YO Metembryo, Neoembryo, and T: ypembryo. 
To these Jackson” has added the Phylembryo, taking it from 
the later stages of the Typembryo to represent the period 
when the animal can be referred definitely to the class to 
which it belongs. 

The succeeding stages in the growth of the animal to 
maturity are termed ‘by Hyatt nepionic (young), nealogic 
(adolescent), and ephebolic (mature), while old age characters 


CU. FE. Beecher—Development of the Brachiopoda. 185 


are called geratologic. The subject of geratology is further 
divided into the clznologze and nostologic stages. 

The application of this nomenclature of the stages of growth 
and decline to the Brachiopoda is shown on the following 


pages. 


Cistella neapolitana Scacchi. 


FIGURE 1.—Protembryo. Unsegmented ovum. 

FIGURE 2.—Protembryo. Ovum composed of two spheres. 
FIGURE 3.—Mesembryo. Blastosphere. 

Figure 4.—Metembryo. Gastrula. (1-4, after Shipley.) 


The Protembryo, as in other groups of organisms, includes 
the ovum and its segmented stages preceding the formation of 
a blastula cavity. Figures 1, 2, show protembryonic stages 
of Cistella. The eggs are spherical, pyriform or ovoid, and 
the segmentation proceeds in a regular manner, resulting in a 
blastosphere composed of equal parts. 

The IMesembryo, or blastosphere, figure 3, has been observed 
in Cistella, Terebratulina, and Lacazella. The blastula cavity 
is small. 

The Metembryo, or gastrula stage, figure 4, is developed 
from the blastosphere in two ways; (@) by embolic invagina- 
tion in Cistella and Terebratulina (Kovalevski and Shipley), 
and (6) by delamination in Lacazella (IKKovalevski). At the 
close of this stage, the archenteron in Cistella is trilobed, con- 
sisting of a central cavity, or mesenteron, connecting on each 
side with the body cavity. 

The Weoembryo, represented by the trochosphere and seg- 
mented ciliated cephalula stages, has been more fully observed 
than any of the preceding. The first advance from the 
completed gastrula is in the separation of the mesenteron from 
the body cavity, and the division of the organism into two 
segments or lobes, the cephalic and caudal, figure 5. Later a 
third or thoracic segment is developed and carries four bundles 
of stiff barbed setze, figure 6. The cephalic and caudal lobes 
are densely ciliated. During the subsequent cephalula period, 
two eyes, then two others appear in Cistella, and at the same 
time the dorsal and ventral sides of the thoracic segment 
become extended over the caudal, and are progressively defined 
as two lobes, figures 5-9, 24, 25. 


136 C. E. Beecher—Development of the Brachiopoda. 


Terebratulina has a tuft of bristles on the top of the 
cephalic segment. In Lacazella, the bundles of sete are 
absent, and the head is more distinetly differentiated from the 
anterior segment than in Cistella. The closing cephalula stage 
in Cistella has an umbrella-like expansion of the cephalic bor- 
der, and the organism becomes a free swimming larva, figures 


1-9. 


Cistella neapolitana Scacchi. 


Figure 5.—Neoembryo. Embryo of two segments. 

FiGuRE 6.—Neoembryo. Cephalula, ventral side; showing cephalic, thoracic, 
and caudal segmeuts, eye spots, and bundles of sete. (5, 6, after 
Kovalevski.) 

Figure 7.—Neoembryo. Lateral view of completed cephalula stage; showing 
extent of dorsal (d) and ventral (v) mantle lobes, and umbrella-like cephalic 
segment. : 

FicurE 8.—Neoembryo. Same stage; ventral view. (7, 8, after Shipley.) 


Larval stages. 


The Zypembryo is the larval stage at which some distinctive 
features make their appearance, but before the special characters 
of the class are to be found, figure 10. It is analogous to the 
molluscan embryo in which a shell gland and plate-like initial 
shell are developed. There is, however, no homology of parts 
or organs between the typembryonic mollusk and brachiopod. 

In Cistella and Terebratulina the development of the typ- 
embryo has been observed, and consists of the folding 
upwards of the lobes which have been developed from the 
thoracic segment to form the mantle, so that they gradually 
enclose the anterior end, figures 24-27. The surfaces of the 
mantle which were exterior in the cephalula have now become 
inner and the bundles of setz have revolved 180°, changing 
their direction from posterior to anterior. This leaves the 
lower part of the thoracic and the whole of the caudal seg- 
ment exposed. The outer surface of the mantle is vested 
with a hard integument, which, upon completion, and before 
the growth of the true shell forms the protegulum. The 


O. E. Beecher—Development of the Brachiopoda. 137 


pedicle at this stage is also defined, being a modification of the 
eaudal segment. It may serve to attach the larva to foreign 
objects, as in Cistella, figure 10, and Terebratulina, or it may 
remain undeveloped for a time as in Glottidia and Discinisca. 
A rudimentary digestive tract is present. 


9 10 


Cistella neapolitana Seacchi. 


FIGURE 9.—Neoembryo. Completed cephalula stage. 

FIGURE 10.—Typembryo. Transformed larva resulting from folding upwards of 
mantle lobes over cephalic segment: ad, muscles from bundles of sete to 
sides of body cavity; di. muscles from dorsal to ventral sides of body; vp, 
muscles from ventral side of body to caudal segment or pedicle. (9, 10, after 
Kovalevski.) 


The body muscles which have been developed thus far 
consist of four distinct pairs. ‘Two pairs lie close to the sides 
of the body cavity, and extend to the points of insertion of the 
bundles of bristles, figure 10, ad. They become after transfor- 
mation the four adductor muscles of the valves. The third 
pair extends from the ventral side of the body to the caudal 
segment, and is converted into the ventral pedicle muscles, 
figures 10, 15, 16, vp. The fourth pair is situated posterior to 
the digestive tract, and extends from the dorsal to the ventral 
wall of the body, figure 10, dz. They form the divaricator 
muscles in the mature brachiopod, figure 16, dz, and are 
divided into or duplicated by a pair of dorsal and a pair of 
ventral divaricators. There is also a pair of dorsal pedicle 
muscles in the larva of Liothyrina and Terebratulina. 


The folding upwards of the mantle lobes forms the first 


138 CU. £. Beecher—Development of the Brachiopoda. 


hinge line of the future valves, A/, figures 26,27. Thus its 
origin is not, as in pelecypods, a line produced by the bending 
of a single plate (Jackson), but is the line along which the two 
mantle lobes are bent against the body. Between them pro- 
jects posteriorly nearly half the body of the animal, and the 
whole opening corresponds to the pedicle opening of later 
stages of growth. The hinge of brachiopods, therefore, is not 
primarily a line of articulation of the valves, but the limiting 
borders between the body and the attached edges of the 


mantle. Secondarily, and during later growth, the extension — 


of the valves along a line of apposition forms a trne hinge 
line. 

The first points of contact of the valves to form the true 
hinge lie adjacent to the right and left sides of the body of 
the animal, at the cardinal extremities, figure 15, ¢ Here 
naturally the first hinge teeth are formed, and their position 
corresponds to that in adult individuals; namely, on each side 
of the cardinal opening. The enlarging of the cardinal 
opening by shell growth results in the gradual divergence or 
separation of the teeth as in Terebratulina. In species with 
extended hinge lines, as in many forms of Spiriter, Orthis, 
and Strophomena, the teeth still lie in their original position 
on each side of the cardinal opening, and the elongation of the 
hinge has come not only from the enlargement of “the opening 
by growth, but by additions at the hinge extremities, so that 
the teeth are situated on each side of the central area, below 
the beak, and not at the cardinal angles. The young of these 
genera, however, all have the hinge teeth at the extremities of 
the hinge, as the cardinal opening then occupies the whole 
posterior area of the shell. 

Adult specimens of Kutorgina (A. cingulata Billings) have 
a deltidium as in Strophomena. The cardinal opening in- 
cluding the deltidium occupies the whole posterior end of the 
shell, and according to a statement made to the writer by Mr. 
Charles Schuchert, there are rudimentary teeth at the cardinal 


extremities. Therefore, this genus represents a nepionic con- 


dition of later forms, and, on account of these and other 
charaeters, it is believed to be related to Orthisina and Stro- 
phomena, of which it is the ancestral type. It consequently 
belongs to the articulate brachiopods. 


The embryonic stages up to this point have frequently been 
compared to similar stages in other organisms, especially in 
the Annelida and Polyzoa. Without repeating these com- 
parisons, which may be consulted elsewhere, * 1%" atten- 
tion is called to the similarity of development of the brachiopod 
typembryo to the larval stages of Spirorbis. There are, how- 


al 


C. E. Beecher—Development of the Brachiopoda. 139 


ever, important structural differences.. An article by J. W. 
Fewkes, ‘On the Larval Forms of Spirorbis borealis Daudin,”’ 
contains a nearly complete and very interesting account of the 
development of this chetopod. There is a striking resem- 
blance in the characters of the cephalula stages in both organ- 
isms, as may be seen on comparison, figures 11, 12. Spirorbis 
develops a posteriorly directed extension from the middle 
segment, called a collar, which in later stages is reflexed an- 
teriorly so as to cover more or less the cephalic portion, thus 
agreeing with the growth and change in position of the mantle 
in Cistella. The ventral lobe is also the larger in both. Many 
other comparisons and homologies have been made by Morse,” 
and the one here described is even more marked than his 
reference to the lobation of the cephalic collar in Sabella. Four 
figures are introduced illustrating the principal changes in 
Spirorbis. They may be compared with the development of 
Cistella shown in figures 6-10. 


Spirorbis borealis Daudin. 


FIGURE 11.—Cephalula, developing lobe from the hody (col.). 

“FIGURE 12.—More advanced stage. 

FIGURE 13.—Larval form before transformation; showing posteriorly directed 
expansion (col) from thoracic segment. 

Figure 14.—Transformed Spirorbis; showing folding upwards of collar partially 
enclosing head. (11-14, after Fewkes.) 


It is not intended by this to indicate a close relationship with 
the cheetopods, for the writer is inclined to accept the opinion 
of Joubin,” that the brachiopods constitute a distinct and 
independent class. 

The Phylembryo, figure 15, differs from the Typembryo in 
(a) the completion of the embryonic shell, or protegulum ; (0) 
the first appearance of the tentacular lobes of the lophophore, 


140 C. E. Beecher—Development of the Brachiopoda. 


or arms; (¢) the usual dehiscence of the four bundles of sete ; 

(7) the obsolescence of the eyes; (¢) the definition of the 
cesophagus and stomach; and (7) the agreement of the mus- 
cular system with that in adult forms. These features, with 
the pedicle which appeared in a preceding stage, represent the 
brachiopod phylum, and are properly referred to the phylem- 
bryonic period of Jackson. Although the molluscan stage 
called the prodissoconch in pelecypods, the protoconch in 
cephalopods and gastropods, and the periconch in seaphopods, 
represents the completed phylembryo of these groups, as the 
protegulum represents a like period in the developing brachio- 
pod, yet there is no homology of distinctive organs. 


15 16 


Cistella neapolitana Scacchi. 


FIGURE 15.—Phylembryo.. Brachiopod; showing shell (protegulum), beginning 
of tentacles of lophophore (/), obsolescence of eye spots, and formation of 
cesophagus. 7, hinge teeth; vp, ventral pedicle muscles 

FIGURE 16.—Nepionie brachiopod; showing distinct tentacles of lophophore, 
mouth and stomach, and transformation of muscles from typembryo, figure 
10; ad, adductors; di, divaricators; vp, ventral pedicle muscles. (15, 16, 
after Kovalevski.) 


The mantle of mollusks is first formed on the posterior 
dorsal side, and is in the shape of a disc, which gradually 
envelops the animal to a greater or less extent, and may 
become distinetly lobed. As has been shown, this organ in 
the brachiopods develops simultaneously from the dorsal and 
ventral side of the thoracic segment of the cephalula, and is 
primarily bilobed. 

The initial shell of brachiopods is not produced from a dis- 
tinct shell gland, as in the mollusca, but is an integument of 
the surface of the mantle lobes, and intimately connected with 
them. The position of the valves is dorsal and ventral. 
The pedicle has no organic similarity with either a foot or 
a byssus. 

The mouth of mollusks (and annelids) is formed below the 
base of the cephalic lobe of the cephalula, and may be the 
blastopore, while in the brachiopods it is near the anterior pole 


C. E. Beecher—Development of the Brachiopoda. 141 


within the cephalic segment. Notwithstanding these dif- 
ferences, so many parts are functional equivalents, that their 
growth and development may be discussed and interpreted in 
the same terms. 

Before passing to later stages of growth which become 

more and more divergent from a common simple type, some 
points previously omitted, relating to Thecidium (Lacazella), 
Lingula (Glottidia), and Discinisea, should be here noted. As 
Laeazella is a form in which the ventral valve in the nealogic 
and ephebolic stages is cemented to foreign objects by eal- 
eareous fixation, it bears about the same “relation to other 
brachiopods that Ostrea bears to Avicula, among the pelecy- 
pods, and a corresponding early absence, or modification, of 
many features present in adult individuals should be looked 
for. From what is known of the geological history of Theci- 
dium, and if the interpretations of its phylogeny by the writer 
are correct, it is derived from an ancestry which had a similar 
condition of fixation as early as the Upper Silurian. Theci- 
dium is apparently not a terebratuloid genus. Its structural 
affinities are evidently with the strophomenoids, especially 
such forms as Plectambonites, Lepteenisca, ete. Briefly the 
reasons for this statement are (@) the presence of a deltidium 
of one plate; () the absence of a true loop supporting the 
arms (the internal calcification or spiculization is confined 
wholly to the mantle, and does not extend to the arms”); (¢) a 
concave place in the cavity of the ventral beak, bearing the 
divaricator muscles ; (¢@) the attached ventral valve, and (e) the 
cardinal processes in the dorsal valve.* The first character is 
of prime importance, because all the strophomenoids and none 
of the terebratuloids have a deltidium of one plate. 

It would appear, therefore, that the early, free swimming, 
larval state, and the later pediculate stage have become lost. by 
acceleration, thus accounting for the very unequal develop- 
ment of the mantle’ lobes in the cephalula stage, and the 
non-active and early sedentary larvee as described by Kovalevski 
and Lacaze-Duthiers. 

The young Lingula (Glottidia) described by Brooks,’ and the 
Discinisea by Miller,” both representing the phylembryonic 
stage, were active and free swimming animals, with rudi- 
mentary pedicles. Terebratulina becomes attached or rests on 
the caudal segment during the cephalula stage (Morse), while 
at the end of this period in Cistella (Covalevski and Shipley), 
there is an active, swimming, ciliated organism, which later 
attaches itself by the pedicle in the typembryonic period. 

* Dall in 1870 (Am. Jour. Conchology) made a clear statement of the characters 


of Thecidium and of many of its radical points of difference with the Terebra- 
tulide, showing that it was entitled to rank as the type of a distinct family. 


142 C. EF. Beecher—Development of the Brachiopoda. 


From the facts, that young individuals of paleozoie species 
belonging to such genera as Zygospira, Spirifer, Orthis, Rhyn- 
chonella, “and Scenidium, have been observed by the writer to 
retain their original relations to the objects of support, and 
that casts of the pedicles of fossil Lingulee and Eichwaldia 
have been described (Davidson,’ Walcott), it cannot be as- 
sumed that the free swimming condition was ever present in 
nealogic or ephebolic individuals. Evidently it has always 
been a larval character. 


Origin of the deltidium and deltidial plates. 


The origin and significance of the deltidium* (=‘ pseudo- 
deltidium ”’) are made apparent in the development of Theci- 
dium, and it may be well in this place to make a few obser- 
vations on the genesis of this important character, and its 
relations to the deltidial plates of other genera, as Rhyncho- 
nella and Terebratula. It has been already noted (Part I), 
that the deltidium in all species possessing it (the Protremata) 
is an embryological, or nepionic feature, which may or may 
not continue to the ephebolic period ; while the deltidial plates 
in other brachiopods (the Telotremata) appear later during the 
nealogic and ephebolic periods, or may never be developed. 
The detailed researches of Kovalevski on Cistella and Thecid- 
ium, together with other observations now first made, furnish 
data for a clear understanding of these differences.t+ 

Figure 18 represents a dorso-ventral section of a ripe cephal- 
ula just before the transformation, and shows the unequal lobes 
of the mantle, v being the ventral lobe, and @ the dorsal; / is 
the head, and. p the caudal segment developing into a pedicle. 
A deposit of integument representing the shell has formed on 
the inner side of the dorsal mantle lobe (ds), and also on the 
adjacent dorsal side of the body lobe (del). A larva somewhat 
more advanced is represented in figure 17, as viewed from the 
dorsal side. The mantle lobe is still directed posteriorly, as in 
the preceding figure, and the underlying shell plate is shown 


*The single plate or covering to the triangular epening beneath the ventral 
beak should be termed the deltidium, as it was thus extensively used by Davidson. 
When it consists of two plates they may he called deltidiai plates. These names 
have been loosely used. In Part I of this paper the deltidium proper is referred 
to as pedicle covering, pedicle sheath, and pseudo-deltidium. Hall and Clarke 
have proposed to call the triangular opening in the beaks of bracniopods, the 
detlhyrium, and the concave plate in the ventral beak of Pentamerus, Orthisina, 
etc , they have termed the spondylium. There yet remains a term for the convex 
plate covering the opening below the beak of the dorsal valve. and resembling 
the deltidium of the opposite valve. For this feature the name chilidiwm (xetAoc) 
is here proposed. 

+ Kovalevski.!® For Thecidium consult the explanation of Pl. LV, figs. 15-26. 
For Cistella, Pl. I, figs. 13-15; Pl. Il, figs. 17, 19-21. 


C. E. Beecher— Development of the Brachiopoda. 148 


Thecidium (Lacazella) mediterraneum Risso. 


Figure 17.—Cephalula; dorsal side. ds, dorsal shell plate; h, head. (After 
Kovalevski.) 

Figure 18.—Dorso-ventral longitudinal section of cephalula of about same age 
as preceding. f, head; d. dorsal mantle lobe; v, ventral mantle lobe; ds, 
beginning of dorsal valve; del, shell plate forming on dorsal side of body; », 
pedicle. (After Kovalevski.) 

Figure 19.—Typembryo. Larva transformed from folding upwards of mantle 
lobes. h, head; ds, dorsal valve; Al, hinge line of dorsal valve; del, sheil 
plate on body and pedicle posterior to hinge line of dorsal valve. (After 
Kovyalevski ) 

Figure 20.—Dorso-ventral longitudinal section of preceding. References as in 
figure 19. vs, ventral valve. 

Figure 21.—Profile view ot nealogic Leptena rhomboidalis. The features of the 
shell are placed and letiered as in figure 20. ds, dorsal valve; hl, hinge 
line; de/, deltidium; p, pedicle opening; vs, ventral valve. 

Figure 22.—Adult Vhecidiwm (Lacazella) mediterraneum; dorsal side; showing 
ventral area and deltidium. 

Figure 23.—Profile of same. References as in figures 20 and 21. 


at ds. In the process of transformation (figs. 19, 20), the man- 
tle lobe is turned forwards in the usual manner, bringing the 
shell on the outside of the animal, so that both dorsal plates 
are now exposed, ds being the dorsal valve, and del the shell 
developed on the dorsal side of the walls of the body. and 
caudal segments. As this plate (del) is below or posterior to 
the hinge line (AZ), and extends down over the pedicle, it is 
evidently the beginning of the deltidium. At the same time, 
there is an extension of the edges of the mantle and pedicle 
on the ventral, or lower side, and shelly matter is deposited, 
forming the ventral valve (vs), figure 20. At this stage the 
hinge line, figures 19, 20, Al, is the line between the dorsal 
mantle shell (ds) and the dorsal body shell plate (del). The 
beak of the ventral valve is separated from the dorsal beak by 
the pedicle and the shell covering to the pedicle and body 


l44 CO. E. Beecher—Development of the Brachiopoda. 


lobe, or the deltidium. The valves afterwards meet at their 
peripheries, the hinge is extended beyond the deltidium, form- 
ing the true hinge of articulate brachiopods. As there is no 
motion between the ventral valve and deltidium, the two 
become ankylosed. Figures 22, 28, showing an adult Theci- 
dium, are lettered in the same manner as the preceding, and 
express the same relation of. parts. 


24. 26. 28. 


Cistella neapolitana Scacchi. 


Figure 24.—Lateral view of compteted cephalula stage. d, dorsal lobe of man- 
tle; v, ventral lobe. (After Shipley.) ; 
Figure 25 —Dorso-veutral longitudinal section of same: showing posteriorly ex- 
tended mantle lobes. ds and vs, inner surfaces of mantle lobes which are to 

form dorsal and ventral valves. (After Shipley.) 

FIGURE 26. -Typembryo. Dorsal view of larva after transformation. h, head; 
ds, dorsal valve; fl, hinge line of dorsal valve: p, pedicle. (After Kova- 
levski.) 

Figur& 27.—Dorso-ventral longitudinal section based on preceding ; showing man- 
tle lobes directed forwards, bringing interior shell-secreting surfaces, ds and 
vs of figure 25, on the exterior. h, head; ds, dorsal valve; hi, dorsal hinge: 
vs, ventral valve; fl’, ventral hinge; p, pedicle. 

FIGURE 28.—Dorsal view of early nepionic shell, showing large posterior open- 
ing between valves. (After Kovalevsk1.) 

FIGURE 29.-—Profile of same. ds, dorsal valve; vs, ventral valve; p, pedicle. 


The deltidium is not, therefore, primarily, on account of its 
manner of origin, an integrant part of the ventral valve, but 
is a shell growth from the dorsal side of the bedy, which after- 


C. FE. Beecher 


Development of the Brachiopoda. 145 


wards becomes attached to the ventral valve, and is then con- 
sidered as belonging to it. 

The further growth of the deltidium around the body and 
pedicle, and its consequent extension into the cavity of the 
ventral umbo, may explain the origin of the spondylium. 

Kovalevski” believed the ventral valve in Thecidium was 
secreted by the expanded edges of the pedicle and the body 
walls, whether or not this is so does not affect the interpreta- 
tion of the origin of the deltidium. From the observations of 
Lacaze-Duthiers,” it seems, however, as though the ventral 
mantle lobe must have formed the shell in the usual way. 
This appears all the more probable from the fact, that the 
lower or ventral valve is punctate, and, so far as known, the 
mantle contains all the cecal prolongations, which alone could 
produce the punctate structure. Careful microscopic examina- 
tion has failed to detect punctze in the deltidia of Thecidium, 
Strophomena, Lepteena, and other punctate genera belonging 
to the Protremata. 

It is true that Aulosteges has spines on the deltidium, but 
spines even when tubular are not equivalent to puncte, as 
shown in Productus, Strophalosia, and some species of Spirifer. 
Aulosteges is a geratalogous genus, which has become exces- 
sively spinose, and has also reverted to ancestral characters in 
its high hinge area and conspicuous deltidium. It is well 
known that even the spires of Spiriferina and the loop of 
Macandrevia are spinose. 

Turning now to Cistella as a representative of the Telotre- 
mata, a different process obtains. 

Figure 24 represents the fully developed, free swimming 
cephalula of Cistella, and shows the extent of the folds of the 
mantle and their posterior direction. Figure 25 represents 
the same in section. The inner sides of the mantle lobes are 
to form the future valves, the dorsal ds, and the ventral vs 
The transformed larva or typembryo is represented in fiewre 
26 and in section in figure 27. It is seen that the tr ansforma- 
tion consists in the folding forwards of the mantle lobes over 
the head segment 4. Now the shell-secreting layers of the 
mantle are exterior, and the two valves begin to form, the 
dorsal shell ds, and ‘the ventral vs. The pedicle and posterior 
portion of the body come out freely between the valves and 
mantle lobes and limit the hinge areas of both, A/ anp Al’. 

The further process of growth increases the distance between 
the initial dorsal and ventral hinges, for while the original 
dorsal beak is usually maintained at the hinge line, the ventral 
beak is progressively removed and the ventral hinge travels 
from its first position at the beak, along the edges of the 
umbo leaving an open triangular area or delthyrium in the 


146 C. EF. Beecher— Development of the Brachiopoda. 


ventral valve oceupied by the pedicle. This condition repre- 
sents the extent of the development of these parts in J/eris- 
tina rectirostra Hall or Gwynia capsula Jeffreys, which lack 
deltidial plates in the adult shell. The young of other telo- 
tremate species, as Magellania flavescens or Terebratulina sep- 
tentrionalis, agree in the same respect. 


30. 33% 30. 


Fiegurb 30.—Delthyrium of young Rhynchonella, without deltidial plates. 

Figure 31.--The same at a later stage, with two triangular deltidial plates. 

FIGURE 32.—The same after completed growth; showing joining of deltidial 
plates, and limitation of pedicle opening to ventral beak. 

Figure 33.--Dorsal view of Magellania flavescens ; showing completed deltidial 
plates, del. 

FIGURE 34.—-The same; profile. ds, dorsal valve; vs, ventral valve; p, pedicle. 

FIGURE 35.-—Dorsal view of umbonal portion of adult Terebratulina septentrionalis, 
with shell removed by acid; showing slight secondary extension of ventral 
mantle around pedicle (consequently small deltidial plates are secreted in this 
species). Mantle areas secreting deltidial plates are shaded. 

Figure 36.—-Dorsal view of umbonal portion of Magellania flavescens, with the 
shell removed by acid; showing the complete envelopment of base of pedicle 
by secondary expansions from ventral mantle, and consequent production of 
deltidial plates filling delthyrium except at pedicle opening. See figure 33. 


An examination of the animal at this stage shows that the 
mantle lobes line only the interior of the valves proper. The 
exposed edges of the mantle are around the peripheries of the 
valves and also that portion of the ventral mantle border limit- 
ing the deltidial opening and passing along the sides of the 
pedicle at its base. The ventral mantle gradually extends 
from each side as two prolongations partially covering the 
opening and enveloping the proximal portion of the pedicle. 


C. EL. Beecher—Development of the Brachiopoda. 147 


As this is an extension of the shell-secreting surface of the 
mantle, there naturally results the formation of two plates 
within the deltidial area. Their structure is commonly punc- 
tate whenever the valves are punctate. 

These outgrowths or extensions of the mantle into the delti- 
dial area finally touch and coalesce until, asin J/. flavescens, the 
pedicle emerges through an opening in the ventral mantle, 
~ and pari passw the deltidial plates unite and limit the pedicle 
opening to the beak of the ventral valve. The latter process 
has been carefully described by Deslongchamps,’ Clarke and 
the writer’ and need not be dwelt on here. Figures 35 and 
36 of the beaks of 7. septentrionalis and M. jflavescens with 
the shell removed show the relations of the ventral mantle to 
the pedicle, and the portions which secrete the deltidial plates. 

The deltidium and delthyrium are often simulated in the 
growth of the dorsal valve in genera having a high cardinal 
area in this valve. Orthis, Leptsena, Clitambonites, Spirifer, 
and Stricklandinia, may be cited as examples. They cannot 
properly be correlated with similar parts in the ventral valve, 
for their origin is quite different. Primarily, a deltidial open- 
ing is for the extrusion of the pedicle and this belongs pyo- 
perly to the ventral valve. The dorsal fissure is the space 
between the diverging teeth sockets, and may be filled by the 
cardinal process, as in Lepteena and Orthis, or it may have in 
addition a convex plate or chilidium covering it, as in Clitam- 
_bonites. In Spirifer and Stricklandinia, the opening remains 
unclosed. 

The true deltidial plates are formed on the side of the pedi- 
cle adjacent to the hinge by extensions of the ventral mantle 
lobe, and begin as two plates. They are likewise expressive 
of maturity, and are of secondary development, while the 
deltidium begins as a single plate in the median line, and is 
eminently a primitive character in the Protremata. 


From present knowledge of the group, it is difficult to offer 
an explanation for the presence of an anal opening in the 
Inarticulata and its absence in the recent Articulata, as the 
solution of the question depends upon whether the class is to 
be considered as progressive or degraded. ‘The dorsal beaks of 
Amphigenia, Athyris, Cleiothyris, Atrypa, and Rhynchonella, 
are usually notched or perforate. The perforation comes from 
the union of the crural plates above the floor of the beak leav- 
ing a passage through to the apex. A similar opening occurs 
between the cardinal processes in Strophomena, Stropheodonta, 
and allied genera, and the chilidium may also be furrowed, as 
in Leptena (=Strophomena) rhombordalis. This character 
is evidently in no way connected with the pedicle opening, 


Am. Jour. Sci.—TuHIrRD SERIES, VoL XLIV, No. 260.—AveustT, 1892. 
10 ; 


148 CO. E. Beecher—Development of the Brachiopoda. 


but points to the existence, in the early articulate genera, of 
an anal opening dorsal to the axial line, as in the recent 
Crania. This dorsal foramen was described and figured by 
King in 1850, Hall® in 1860 and by several authors sinee, 
and has commonly been termed a visceral foramen. 

(Khlert™ suggests that it was probably occupied by the ter- 
minal portion of the intestine. The persistence of the foramen 
seems to indicate an anal opening. In reference to this 
character and the obsolescence of the eyes the class must be 
viewed as retrogressive since paleozoic time. Other features, 
however, are manifestly progressive; namely, the gradual 
shortening, through time, of the posterior elements of the 
animal, as the pedicle, visceral portions, and internal shell 
structures, and the expansion of the anterior parts, as the shell 
and brachia. 

A further advance in specialization is shown in the limitation 
of the pedicle opening wholly to the ventral valve in the 
higher rhynchonelloids, athyroids, spiriferoids, and terebratu- 
loids. The absence of punctee in all the early radicles and 
their subsequent development in the derived types may also 
have a similar bearing. 

The features and importance of the protegulum have pre- 
viously been discussed.’ It is merely noticed here as the 
embryonic shell of the completed phylembryonic period, for it 
is the first stage which can be observed among the fossil 
species, and is the initial point for the discussions of the 
relations and affinities of recent and fossil forms. Of the 
protegulum and later stages, there is abundant material avail- 
able in nearly every family of brachiopods, ranging through 
their entire geological history. 


Post-embryonic stages. 


In discussing the post-embryonic stages of growth two 
aspects of development must be clearly differentiated ; (a) the 
ontogenetical, and (0) the phylogenetical. The ontogeny of a 
form like Schizocrania may be conveniently divided into the 
nepionic, nealogic, and ephebolic periods, and such stages may 
be clearly defined. The ephebolic stage of Schizocrania, how- 
ever, is like a nealogic stage of Orbiculoidea. In other words, 
Orbiculoidea, in its development, passes through a Schizoerania- 
like stage before reaching maturity.* These facts must be 
viewed from a phylogenetic standpoint. Moreover, in the 
geological history of a group, certain ephebolic characters of 

* Attention was called to this fact in a publication preliminary to vol. viii of 


the Paleontology of New York, pp. 131, 132, issued February, 1890. Also the 
development of the pedicle opening in Orbiculoidea was fully described. 


C. FE. Beecher—Development of the Brachiopoda. 149 


early species may become accelerated, and pass into the nealogic 
period of later forms, while other characters remain ephebolic. 
Discinisea offers an illustration of this. Its nealogic characters 
agree with Orbiculoidea in the form of the valves and in the 
pedicle notch, but the circular or elliptical form of the dorsal 
valve in adult and nealogic Orbiculoidea appears so early in 
Discinisea, that it marks all the nepionic stages. The inter- 
pretation of these facts is, of course, very evident, and will be 
subsequently given in detail. Attention is here called to the 
statement, that while nepionic, nealogic, and ephebolic stages 
represent equal intervals in the life of each individual, they do 
not represent conditions of growth, or the possession of 
characters which always agree stage for stage in the species of 
one family or of different families. 

Other distinctions to be made whenever possible are (a) 
whether certain characters (natural or acquired) belong to a 
species by inheritance, or (>) are mere adaptations to special 
conditions of environment arising at any time in its history. 
A clear understanding of the first will lead to the true 
phylogeny of a species or genus, but to reach this the charac- 
ters of the second category must be excluded. Thus in the 
series of Schizocrania, Orbiculoidea, and Discinisca, already 
cited, there is an apparent genetic connection in the facts as 
stated. The contrary must be the case witha shell like Lingula 
complanata Williams, and L. riciniformis Hall which initiate 
a holoperipheral* mode of growth in the ephebolie period, for 
this agreement in the method of concrescence with adult 
Orbiculoidea here appears in the mature stages of this species, 
and being absent in the early members of the genus cannot 
therefore be an ancestral character. It is a morphological 
equivalent, which may or may not be continued in the later 
species of the series. . 

Whenever features are present which can be referred to an 
ancestral origin, their elimination can take place only by the 
process of acceleration of development. On the other hand, 
there may be secondary characters of dynamical or homoplastic 
origin which appear simultaneously or independently in dif- 
ferent groups belonging to diverse genetic lines, as the 
deltidial plates of the Rhynchonellide, Terebratulide, and 
Spiriferide. Further, many such secondary features may 
occur anywhere in the geological history of the group, as the 
high hinge area of Orthisina, Spirifer, Syringothyris, and 
Thecidium. These statements are in full accord with what 
Hyatt has determined in the Cephalopoda, and the application 
of such ideas affords a fertile field of research. 


* OA6c, whole; mepiépeva, circumference. 


150 C. E. Beecher—Development of the Brachiopoda. 


Preliminary to a study of the stages of growth observed in 
the different orders, a simple characteristic example of each 
will be taken to show the limitations of the post-embryonie 
periods. 

Nepionic period.—In brachiopods, as in pelecypods, this 
period represents the growth of the true shell immediately 
succeeding the embryonic shell or protegulum, and before the 
appearance of definite specific characters. In general, the 
nepionic shells of all groups are marked only by fine concen- 
tric lines of growth, and are therefore nearly smooth. Some- 
times, however, a few radiating strie or other ornaments may 
appear over the nepionic portion, but this is not the prevailing 
rule. Obolus pulcher Matthew shows a cancellated nepionic 
stage and is one of the most striking exceptional examples. 

Plate I, figure 1, represents the nepionic stage of Glottidia 
albida, drawn from the beak of a well-preserved adult. The 
shell at this period had a short straight hinge (originally the 
hinge of the protegulum), with lines representing anterior and 
lateral growth, making the outline broadly ovate. It is 
divided from the succeeding growth of later stages by a strong 
varix. The form is suggestive of Obolella, and as this is the 
early form of growth of many of the Lingulide and allied 
families, it is “here called the Oboledla- -stage. It is not 
known that otherwise the characters agree with those of 
Obolella, but as it is characteristic as well as descriptive the 
name is used to designate this form of nepionic growth when- 
ever present. 

The nepionic stage of Orbiculoidea minuta, figure 4, shows 
a continuance of the straight hinged condition after the com- 
pletion of the embryonic shell, with nearly equal incremental 
lines. As this agrees with the shell of Paterina it is called the 
Paterina-stage. Tlie pedicle emerged freely between the 
_ cardinal margins of the valves. It will be shown that both 

this and the Obolella-stage are represented in the nepionic 
periods of many genera belonging to the Atremata. They 
may succeed each other in a single species or one alone may be 
present. In case both appear, the Paterina stage is always the 
first one to be developed. 

The nepionic stage of Leptena (=Strophomena) rhombor- 
dalis, fig. 7, Pl. I, is represented by a shell without radii, 
having a comparatively large pedicle opening in the ventral 
valve and a large deltidium. The hinge is not well defined 
and the shell is discinoid in form. This term is not used to sug- 
gest any special affinities with true discinoid genera, as Orbicu- 
loidea or Discinisca. - The proper name for this stage is not 
yet apparent to the writer. The external characters as ex- 
pressed by both valves are manifestly nearer to Kutorgina 


C. E. Beecher—Development of the Brachiopoda. oil 


than to any telotremate genus. Until the early forms belong- 
ing to the articulate brachiopods, especially to the orthoid and 
strophomenoid groups, have been thoroughly studied, the 
interpretation of the nepionic Leptena rhomboidalis may be 
uncertain. It should be noted, however, that the young of 
Chonetes, Productus, Stropheodonta, Orthothetes, Leptzena, 
Plectambonites, and Strophomena, all have little or no indi- 
cation of a straight hinge line, and that the extension of this 
member takes place during later nealogic and ephebolic growth. 
This in itself is significant, but is more marked when taken 
with the growth stages shown by some species of Strophomena 
which have after the protegulum, a Paterina-like stage, with 
straight hinge in dorsal valve, succeeded by holoperipheral, 
discinoid, nepionic growth, and finally a renewal of a straight 
hinged condition. Thus it has an early straight hinged form, 
which is lost during the next stage of growth, and again 
appears, and is progressively elongated during nealogic and 
ephebolic growth. 

The nepionic stages of Terebratulina septentrionalis, fig. 10, 
Pl. I, represent a decreasing extension of the cardinal line from 
the protegulum, an open delthyrium, the absence of radii, and 
the introduction of the shell puncte. The crura at this stage, 
as shown by Morse, are short and stout, and the loop is unde- 
veloped. 

Nealogic period.—Diuring the progress of this period all the 

features which reach their complete growth in the adult 
organism are introduced and progressively developed. Usu- 
ally they appear in succession, and gradually assume mature 
conditions. Thus in many species with radiate plications or 
strie, a few radii appear in early nealogie growth, and are 
added to until the full number is present. Species with 
deltidial plates develop them in this period. The early stages 
may offer many points for comparison with the adult, but later 
stages usually differ little except in size. Figures 2, 5, 8, 11, 
Plate I, represent a nealogic stage in each of the four species 
taken as examples. Others from the same species could be 
given, but these suffice to show that one or more character- 
istic adult features have made their appearance. 

LEphebolic period.—The period of complete normal growth, 
or the maximum of individual perfection. This corresponds 
to the adult, or mature organism, and is so well understood 
that no further explanation is necessary. For the sake of 
completing the series, the ephebolic shells of the species given 
are represented in figures 3, 6, 9, 12, Plate I. 

Geratologic period. —The variations due to old age may be 
numerous and coraplex. As shown by Clarke and the writer,” 
the valves generally become thickened, and, as a consequence, 


152 C. E. Beecher—Development of the Brachiopoda. 


the margins are truncate or varicose, the vertical diameter of 
the shell is increased, the beaks involuted, and the margins of 
the valves often lose the ornamentation characteristic of the 
species. The deltidial plates or deltidium may be resorbed as 
well as the beaks of the valves. Usually the ephebolic charac- 
ters disappear in inverse order to their introduction. This is 
called the clinologic stage of geratology by Hyatt. Thus ina 
normal adult brachiopod having a plicate shell and deltidial 
plates, which characters were introduced during the nealogic 
period, the expression of old age will be found in the absorp- 
tion of the deltidial plates and in the obsolescence of the 
plications. Large specimens of Zerebratella transversa Sow. 
often furnish examples of this clinologie stage. 

The geratologic development of Bilobites’ consists in the 
obsolescence, in B. varicus Con., of the bilobed form of the 
shell, thus reverting to an early nealogic condition equally 
characteristic of L. bilobus and B. Verneuilianus. 

Another aspect of growth and decline is manifest when the 
size of individuals and the chronological history of groups are 
taken into consideration. Each genus and family began with 
small representatives, and rapidly developed the more radical 
varieties of structure. Then came the culmination and final 
reduction in size, with abundance of geratologousand pathologic 
forms. The oldest known shell with calcareous spires, Zygo- 
spira, is a comparatively minute form. Nearly all the types of 
the suborder to which this genus belongs (Helicopegmata) appear 
in the Upper Silurian. Species presenting the maximum size 
belong to the Devonian and Carboniferous. Before the extine- 
tion of the suborder in the Trias, the individuals are small, and 
such abnormal genera as Thecospira, Koninckina, and Amphi- 
celina, abound. Productus begins with small species (Produe- 
tella) in the Lower Devonian, and in the Carboniferous attains 
the largest dimensions of any known brachiopod (P. giganteus). 
During the Permian, the species have dwindled in size, and 
the geratologous Strophalosia and Aulosteges are the chief 
representatives. 

The culmination of geratologous growth results in the re- 
version of the animal to its own nepionic period, and is called 
the nostologic stage. As this is an extreme condition, it can 
be found only in certain genera and species which have been 
developed by a process of accelerated geratologous heredity. 
If Gwynia* is accepted as a valid genus, it belongs to a pro- 
nounced nostologic type. The shell has a small internal plate 
on each side of the dorsal umbo, evidently the bases of crural 


*Some authors have been disposed to consider this form as the young of a 
species not yet determined. It has also been referred to Macandrevia cranium, 
Cistella cistellula, and C. neapolitana. This question cannot at present be deter- 
mined, although some characters of the shell indicate a mature organism. 


- 


C. EF. Beecher—Development of the Brachiopoda. 158 


plates. King,” the author of the genus, states that the labial 
appendages are attached directly to the shell, and not toa 
loop, as in other genera of the family. Cistella may be taken 
as a representative of nostologic development among the 
terebratuloids. The species are smooth, or pauciplicate, and 
small; deltidial plates obsolescent, loop more or less unde- 
veloped. In CC. neapolitana, the lamelle of the loop are 
nearly obsolete and are free only near the crura, while the 
anterior portions are confluent with the valve (Shipley). A 
slight progression of these reversions would naturally result in 
a degenerate form like Gwynia, which is without a calcareous 
loop; with no surface ornamentation ; deltidial plates absent, 
puncte few and large, all of which features are strictly nepi- 
onic. Besides Cistella and Gwynia, other loop-bearing genera 
present nostologic features of importance in a natural classifi- 
cation. ‘These consist mainly in their small size; the absence 
of surface ornaments; the obsolescence of deltidial plates, and 
the loss of a complete loop supporting the arms. In the 
Terebratulidee, Kraussina and Platydia may be mentioned as 
belonging to geratologous types with a nostologic tendency. 
Likewise, in other groups, Atretia in the Rhynchonellide, and 
Strophalosia and Aulosteges in the Productide, are examples 
of nostologic types. 

Cistella and Gwynia among the genera of brachiopods, 
therefore, bear the same relation to the terebratuloids that 
Baculites among the cephalopods bears to the ammonoids. 


Synopsis. 

Protembryo.—Ovum and segmented stages before formation of 
blastula cavity. 

Mesembryo.—Blastosphere. 

Metembryo.—Gastrula. 

Neoembryo.—Trochosphere and cephalula, with posteriorly 
directed mantle lobes, and bundies of setze from body segment. 

Typembryo.—Larva with mantle lobes folded anteriorly over 
head segment. 

Phylembryo.—Brachiopod covered by protegulum, tentacles of 
arms developed, bundles of sete dehisced, definition of stomach 
and cesophagus, direct transformation of larval muscles into 
those corresponding to muscles of adult animal. 

Deltidium.—A single plate developed at an early period by 
the body and pedicle of animal posterior to dorsal hinge, and 
later ankylosed to ventral valve. 

Deltidial plates.—A nealogic and adult feature produced by 
the extensions of the ventral mantle lobe into the delthyrium. 

Brachiopoda.—Retrogressive in loss of anal opening and eyes, 
progressive in concentration of posterior elements, expansion of 
anterior elements, and limitation of pedicle opening to one valve. 


154 CU. E Beecher—Development of the Brachiopoda. 


Nepionie period.—Young shells before the appearance of dis- 
tinctive specific characters. 

Nealogic period.—Progressive development of the specific fea- 
tures which reach their complete growth in the adult. 

E/phebolic period.—Normal adult condition, 

Geratologic pertod.Special manifestations of old age in ontog- 
eny and in phylogeny. 

Nostologie types.—Extremes of geratology represented by Cis- 
tella, Gwynia, and Atretia. 


Yale Museum, New Haven, Conn., May 31, 1892. 


REFERENCES. 


1. Beecher, C. E., 1891.—Development of the Brachiopoda. Part I. Introduc- 
tion. This Journal, vol. xli, April. 

2. Beecher, ©. E., 1891.—Development of Bilobites. This Journal, vol. xlii, July. 

3. Beecher, C. KE. and Clarke, J. M., 1889.—The Development of some Silurian 
Brachiopoda. Mem. N. Y. State Museum, vol. i, no. 1. 

4. Brooks, W. K., 1879.—The Development of Lingula and the Systematic Posi- 
tion of the Brachiopoda. Johns Hopkins Univ., Chesapeake Zool. Lab.. 
Sci., Results Session of 1878. 

5. Davidson, T., 1851-1885.—A Monograph of the British Fossil Brachiopoda. 
Pal. Soc. 

6. Deslongchamps, E., 1862.—Note sur le développement du deltidium. chez les 
brachiopodes articulés. Bull. Soc. Géol. France, 2° ser. t. xix. 

7. Fewkes, J. W., 1885.—On the Larval Forms of Spirorbis borealis, Daudin. 
American Naturalist, March. 

8. Hall, James, 1860.—Paleeontology of New York, vol. iii. - 

9. Hyatt. A., 1888.—Values in Classification of the Stages of Growth and 
Decline, with Propositions for a New Nomenclature. Proe. Boston Soc. 
Nat. Hist., vol. xxiii, March. 

10. Hyatt, A., 1889.—Genesis of the Arietida. Mem. Mus. Comp. Zool., vol. xvi, 
no 3. 

11. Jackson, R. T., 1890.—Phylogeny of the Peleeypoda. The Aviculide aid 
their Allies. Mem. Boston Soc. Nat. Hist., vol. iv, no. viii. 

12. Joubin, L., 1886.—Recherches sur ]’Anatomie des Brachiopodes Inarticulés. 
Archiv. Zool. Exp¢rimentale, 2° ser. t. iv. 

13. King, W., 1850.—A Monograph of the Permian Fossils of England. Pal. Soe. 

14, King, W., 1859.—On Gwynia, Dielasma and Macandrevia, three new genera 
of Palliobranchiate Mollusca, one of which has been dredged in Belfast 
Lough. Proce. Dublin Univ., Zoél. Bot. Assoe., vol. i. 

15. Kovalevski, A. O., 1874.—Observations on the Development of Brachiopoda. 
Proceedings of the Session of the Imperial Society of Amateur Natural 
ists, ete., held at the University of Moscow, 11th year. vol. xiv. 

16. Lacaze-Duthiers, H., 1861.—Histoire naturelle des Brachiopodes vivants de 
la Mediterranée. Ann. Sci. Nat. Zool., t. xv. 

17. Morse, E. S., 1873.—On the Early Stages of Terebratulina septentrionalis 
(Couthouy). Mem. Boston Soe. Nat. Hist., vol. ii. 

18. Morse, E. S., 1873.—Embryology of Terebratulina. _Mem. Boston Soc. Nat. 
Hist., vol. ii. 

19. Morse, E. S., 1873.—On the Systematic Position of the Brachiopoda. Proc 
Boston Soe. Nat. Hist., vol. xv. 

20. Miller, F., 1860.—Beschreibung einer Brachiopodenlarve. Archiv. Anat. 
Physiol., Jahrg. 1860. 

21. @hlert, D. P., 1887.—Brachiopodes. Manuel de Conchyliologie, Paul Fischer. 
Appendice. 

22. Shipley, A. E., 1883.—On the Structure and Development of Argiope. Mitth 
Zool. Station Neapel, bd. iv. 

23. Walcott, C. D., 1888.—A Fossil Lingula preserving the Cast of the Peduncle. 
Proc. U. 8. Nat. Mus. 


Wells, Wheeler and Penfield—Halides of Silver, etc. 155 


EXPLANATION OF PLATE. 


Glottidia albida Hinds. 


Fre@cre 1.—Nepionic shell; Obolella stage. x 36. 

FIGURE 2.—Nealogic stage; showing anterior growth producing Lingula-like 
form. x16. 

FiGuRE 3.—Ephebolic stage. x 3. 


Orbiculoidea minuta Hall. 


Figure 4.—Nepionie shell; Paterina stage. x 36. 
FIGURE 5.—Nealogic stage; first holoperipheral growth. x 16. 
Figure 6.—Ephebolie stage. x10. 


Leptena rhomboidatis Wilck. 


FIGURE 7.—Nepionic stages, with short hinge. x 36. 
Figure 8.—Early nealogic stage, with radiating striz. x 10. 
FIGURE 9.— Ephebolic stage. x 3. 


Terebratulina septentrionalis Couth. 


FictreE 10.—Nepionic stage, with open delthyrium. x 26. 
FIGURE 1].—Harly nealogic stage, with radiating striae. x16. (After Morse.) 
FIGURE 12.—Ephebolic stage. x3. (After Davidson.) 


@ 


Art. XX.—On some Double Halides of Silver and: the 
Alkali-metals; by H. L. Wetts and H. L. WHEELER. 
With their Orystallography ; by 8S. lu. PENFIELD. 


_ DuRING a systematic search for well crystallized salts of the 
type M’H|. AgH1,* which we were anxious to obtain on 
account of their probable isomorphism with the alkaline 
trihalides, three well defined compounds of another type, 
2M’H1. AgH1, were obtained. Our experience indicates that 
these 2:1 salts are more easily prepared and crystallize better 
than the 1: 1 compounds. 

The bodies to be described are 2CsCl. AgCl, 2RbI. AgI and 
2KI.AgI. Two of these are believed to be new salts; the 
other, 2KI.AgI has been described by Boullay.t We have 
not obtained a complete series of these compounds, for good 
crystals could not be made of the other members, and, under 
the circumstances, no products were analyzed except such as 
could be measured. 

The compounds are interesting from the fact that they do 
not conform to Remsen’s law concerning the composition of 
double halides,t for, contrary to this, they contain a number of 
alkali-metal atoms which is greater than the number of halogen 
atoms belonging to the silver. In his latest contribution to the 


* This Journal, IIf, xliii, 30 and 485. + Ann. Chim. Phys., IT, xxiv, 377. 
¢ Am. Chem. Jour, xi, 291. 


156 Wells, Wheeler and Penfield—Double Halides of 


subject,* Remsen states that the exceptions to his law are “ not 
more than three or four out of over four hundred.” The work 
here described confirms the result of Boullay, adds two more 
exceptions to the law and points to the existence of a greater 
number of compounds of the same type. It may be men- 
tioned that a considerable number of other exceptions to this 
law have recently been established in this laboratory and will 
soon be described. 

Preparation and properties.—The salts are made by satu- 
rating a very concentrated, hot solution of an alkaline halide 
with the corresponding silver halide, filtering » cooling to erys- 
tallization and, if necessary, evaporating the mother-| “liquor at 
ordinary temperatures. If the solutions are too dilute, in some 
cases at least, the 1:1 salts are formed. The compounds have 
little tendency to crystallize well and many trials are usually 
necessary in order to obtain satisfactory products. The salts 
are all white. They are readily decomposed by water. 

Method of analysis—The products analyzed were in the 
form of erystals of such size that it was certain that they were 
not mixed with other substances. In preparing them for 
analysis the mother liquor was removed rapidly and completely 
by pressing them between smooth filter-papers and great care 
was. taken to avoid any evaporation of the liquid which ad- 
hered to them. The analyses were made by treating them 
with a sufficient amount of water acidified with nitric acid and 
weighing the silver halide thus separated. The filtrate from 
this was used for determining the remaining halogen or the 
alkali-metal. 


ANALYSES. 
Calculated for 
Found, 2CsCl. AgCl. 
@assiumy: oe oe ee eae Beige 55°38 
Silliverae ts os tps ay eee eerste 24°85 22°47 
Chiorine see eee pan Ae D1 155 
Calculated for 
Found. 2Rb1. Agl. 
Rulbidiuim yo eee 25°05 25°91 
STVe Thc eh koe Abas iar 32 16°36 
Lodine ses ied ae 57°53 Sie 
99°90 100:00 
Calculated for 
Found. 2KI. Agl. 
J RAOYENSISITO TO yr ses ek Lin 13°79 
Sil Vere) ses Mena 18°73 19°04 
Todiness2 2: 2a) Be ea aes a Ai! 67°17 


* Am. Chem. Jour., xiv, 87. 


Silver and Alkali-metals, with their Crystallography. 157 


Crystallography.—tThe three salts are isomorphous and crys- 
tallize in the. orthorhombic system. The forms which were 
observed are: 

a, 100, 4-7 TWO: Te d, 101, 1-i 
b, 010, i-% nm, 120, 4-3 a, 301, 3-1 

The axial ratios and some of the prominent angles are given 
_in the following tables, the fundamental measurements being 
marked by an asterisk. The crystals did not yield very accu- 
rate measurements. 


Gen Ot ac 

2CsCl. AgOl 0971 : 1: 0°244 

2RbI . Agl Oi iia les 02236 

2KI . Agi OD dies L234 

mam, 110,110 nan, 1204120 dad, 101,101 
2CsCl. AgCl 88° 18” *54° 297 *287 117 
2RbI . Agl ¥y8 40 jay 12 22 2 
2KI . Agl *88 40 54 12 x27 (0 


2 CsCl. AgC] was made in 
minute prisms, less than a 
millimeter in diameter, having 
the habit shown in fig. 1. The 
measurements are only approxi- 
mately correct. 

Two crops of 2RbI. Agl 
were examined. One was like 
fe. 1 im habit, the ‘other in 
plates, fig 2, The crystals 
were nearly 10" in length. On 
this salt a cleavage, parallel to 
a, was observed; also, as small 
faces, the forms 6 and a, which are not shown in the figures. 
In convergent polarized light an obtuse bisectrix was seen, 
normal to a, the axial plane being the brachy-pinacoid. 

2KI.AgI was made in prismatic crystals, over 10™™ in 
length and having the habit and forms shown in fig. 1. 

Sheffield Scientific School, April, 1892. 


1. 2. 


Art. XXI.—On the Cesium and Rubidium Chloraurates 
and Bromaurates; by H. L. Wreuis and H. L. WHEELER. 
With their Crystallography ; by 8. L. PENFIELD. 


A stupy of the campounds to be described was undertaken 
in the hope that some crystallographic analogy would exist 
between them and the alkaline pentahalides described ina 
previous article.* No such analogy has been found in spite of 


* This Journal, xliv, 42. 


158 Wells, Wheeler and Penfield—Casium and 


the similarity of such formule as CsCl. Cl,I and CsCl. Cl,Au, 
but since some of these gold salts have never been described and 
as they show some interesting relations among themselves, our 
results are deemed worthy of publication.* 

Th. Rosenbladt,+ in an article on the solubility of the chlor- 
aurates, states that the cesium and rubidium salts lose their 
water of crystallization almost completely when dried over 
sulphuric acid. He gives no statement of the amount of 
water, but refers to his dissertation of 1872 which is inacces- 
sible to us. He mentions, however, that the crystals of both 
salts belong to the monoclinic system, so that it is probable 
that the compounds he obtained were the ones that we have 
found to be anhydrous. 

The compounds that have been prepared are CsAuCl,, 
2CsAuCl,. H,O, CsAuBr,, RbAuCl, and RbAuBr,. We have 
attempted in each case to obtain bodies containing more czesium 
and rubidium, but no evidence of their existence has been 
found. 

An investigation of the corresponding iodine compounds 
was also undertaken, but, on account of the instability of aurie 
iodide, we did not obtain any pure or well crystallized products. 

Preparation :—The salts are so insoluble that they form 
precipitates when moderately concentrated solutions of the 
component salts are mixed, and the products are readily recrys- 
tallized from water or from the mother liquors. It is usually 
immaterial whether the solutions are neutral or acid or whether 
the gold or alkaline halide is in excess, but the salt 2CsAuCl,. 
H,O requires special conditions for its preparation, for it is 
apparently formed only when a large excess of gold chloride 
is present and when the solution does not contain much free 
acid. We have used four atoms of gold to one of cesium in 
making this salt, but it usually requires repeated trials under 
these conditions before it is obtained free from the anhydrous 
compound. The two salts are however so distinct in form that 
there is no difficulty in distinguishing them. 

Properties :—The color of CsAuCl, and of 2CsAuCl,. H,0 
is golden-yellow; RbAuCl, is yellowish-red ; the two bromides 
are black, but give a dark red powder. 

AJjl the salts are sparingly soluble in water, especially when 
cold, and the cesium compounds are less soluble than the 
rubidium. All of them are only slightly soluble in alcohol 
and insoluble in ether. 

* The announcement by Professor Remsen (Am. Chem. Jour., xiv, 89), that he 
and Mr. H. C. Jones proposed to examine the gold-rubidium halides, was not 


made until after the work described in this article had been completed. 
+ Berichte, xix, 2535. 


Rubidium Chloraurates and Bromaurates. 159 


Methods of analysis :—The erystals were prepared for analy- 
sis by quickly pressing them between smooth filter-papers and 
finally allowing them to become air-dry. The hydrous cesium 
chloraurate, however, loses its water and becomes opaque on 
exposure. It was therefore dried as rapidly and thoroughly 
as possible on paper and was put into a weighing-tube as soon 

as some of the fragments began to lose their transparency. 

_ Gold was determined by precipitation with ammonium oxa- 
late or with sulphurous acid. The filtrate from the metallic 
gold was used either to determine the alkali-metal as normal 
sulphate or the halogen by the usual gravimetric method. 
Water was determined by the method used in the combustion 
of organic compounds, the halogens being held back by a mix- 
ture of lead chromate and lead oxide. The absence of water 
in the anhydrous compounds was established by the use of the 
same process. 


ANALYSES. 
Calculated 
Found. for CsAuCl, 
@zesiam=s o_o. 28°11 28°16 
Gold@ 24 32232. 4s Glee 41°77 
Chiormess= 2. 29°91 30°06 
99°63 
Calculated 
Found. for 2CsAuCl,. H.O 
@eesiuimy 2 2 ee DDS} bed ite) 27°63 
Goldwsncs tou 40°23 kei =f ank 40°99 
Chlorine ee 29:07 pts ae 29°50 
VA GNIS aah a cas 2232 DOB abs DOK 2 1°87 
98°86 
Caleulated 
Found. for CsAuBr, 
@aesiume a a5 PDO aes 20°45 
Goldpie S306 30°32 30°26 30°34 
Brome w= 512s 49°31 Nels ly 49°21 
100°36 
Calculated 
Found. for RbAuCl, 
Eubrdiun 2 25.2 NS 20°14 
Cold esa 45°53 46°46 
Chilorime_ -2-. _2 ~32°98 33°40 


* From a separate product. 


160 Wells, Wheeler and Penfield—Cosium and 


Calculated 
Found. for RbAuBr, 
Reid aires oe ee 14°18 
Goldie eee ee 32°54 32°73 
Bromine 22e-= aes 53°08 


Cry pystallogr aphy :—The erystallization of CsAuCl,, CsAuBr,, 
RbAuCl, and RbAuBr, is monoclinic. The four salts form 
an isomorphous group ‘and are identical in crystalline habit. 
The forms which have been observed on them are: 


c, 001, O d, 021, 2-2 p, 111, 1 
m, 110, I é, 201, 2-7 
1 De 


The crystals are prismatic and are usually terminated by e, 
fig. 1. When other faces are present they are always small, as 
represented in fig. 2. The pyramid p, which is not shown in 
the figure, frequently occurs as a small face, replacing the edge 
between d@ and ¢. Among the crystals of CsAuBr, several 
twins were observed, having p, 111 as the twinning plane, fig. 
3, while fig. 4 represents a crystal of RbAuBr, twinned about e, 
201. The letters belonging to the parts in twin position - are 
underlined. Both kinds of twins are abnormally developed as 
represented in the figures. In all four compounds the cleay- 
age is perfect parallel to the base. 

The rubidium salts, being the most soluble, form readily in 
large crystals, several centimeters in length. The chloride, 
especially, yielded magnificent crystals, which frequently were 
only limited in length by the size of the vessel and volume of 
the solution containing them. The csium salts are less 
soluble and were made in small prisms, seldom over 5™™ in 
length. The crystals were frequently hollow or cavernous at 
the extremities, this was especially true of the two bromides. 
The faces, for the most part, gave excellent reflections of the 
signal on the goniometer. 


Rubidium Chloraurates and Bromaurates. 161 


The axial ratios are as follows: 


Cs AuCly CsAuBr4 
a@:b:é6 = 11255: 1:0°7228 a@:b:é = 11359: 1: 0°7411 
B= Wl? BG B= 0° 244’ 
RbAuCl, RbAuBr, 
&:b: ¢ = 11954: 1:0°7385 @:b €: =1:1951:1:0°7256 
B= 715° 32’ @ = 76° 532’ 


In the following tables the angles which were chosen as 
fundamental are marked by an asterisk. 


CsAuCl, CsAuBr, 
= SS)" f= pa = 

Measured. Calculated. Measured. Calculated. 
mam, 110.110 = *93° 46’ *93° 537 
MO MORO TS (10 2X3 te Bete *76 46 
mad, 110,021= 44 6 44 7 43. 23, AZ 204 
na OQ lee ly — 320123 32 404 
Gx G ON -~ DO Bers | ly WS Bil (3) BS) 
ma e, 1104201 =*60 36 *60 41 
CAC OO Ae Op 4 2.0 64 18 
mam, Reéntrant angle of twin, 2t 58 27 58 

RbAuCl, RbAuBry, 
— —— — AW 

Measured. Calculated. Measured. Calculated. 
mam; 110.110 = *98° 21’ *98°. 40’ 
Mew cw VOrAO0l— 80) 236 *81 30 
mad, 110,021 = 44 57 45 124 
Chex jo, WAN zo 31) 26 31 354 
dn. e, 021% 201= ‘ 72 28 72 26 
Meer Ora2 Ol 62-9 12 62 9 62 214 
67.0, VLAD = “GY 2 59° 59” 
Ged 0216402) — 1 0n 220 110) «44 109 26 
mam, Reéntrant angle of twin, 55 42 By) LY 


In their axial ratios the two cesium salts are very similar, 
as are also the two rubidium salts, while the rubidium com- 
pounds differ considerably from those of cesium, especially in 
the relation of d to the other axes and in the angles (Bish as 
therefore evident that the replacement of one metal by another 
in these salts has a considerable influence upon their form, 
whereas, as we have shown, such a replacement in the cesium 
and rubidium trihalides has little or no effect. There seems to 
be no regularity in the influence of the replacement of chlorine 
by bromine in these gold salts, for in the caesium compounds 


the chloride has a slightly nome nce ¢ and a greater angle £ 
than the bromide, while in the rubidium salts exactly the 
reverse is true in both cases. This unexpected relation between 
the chlorides and bromides has been confirmed by repeating 
the measurements, especially of the angle m~Ac, using both 
erystal and cleavage faces. It is certain that this angle i is about 
a degree greater with the chloride than with the bromide in 


Am. Jour. Sc1.—THIrRD SERIES, Vou. XLIV, No. 260.—Avaust, 1892. 
11 


162 Wells, Wheeler and Penfield—Cesium, ete. 


the cesium salts, while in the rubidium compounds it is about 
a degree less. 

5. The erystallization of 2CsAuCl,.H,O is ortho- 
rhombic. This salt was repeatedly made but only 
one crop of crystals was obtained which was 

||| suitable for measurement. These were thin 
A tp plates, having the habit shown in fig. 5. They 
: were not over 5™" in length and were only a 
fraction of a millimeter thick. On removal from 
the mother liquor, or from a moist atmosphere, 
=== the transparent plates rapidly became opaque 
and the faces lost their luster so that only approximate measure- 
ments could be obtained. 

The forms which were observed are: 
a, 100, 7-7 m, 110, 1 d, 101, 1-7 
b, 010, 7-2 n, 120, 7-3 


Ht 


The axial ratio is as follows: 
‘ WbesCe—0;625):01h 10224 
The following measurements were made. 


aam, 100 «110 = about 32 ab, 1004010 = about 90° 
hos Wh TOOK 120 512 Ohh Mik MOS AS 


Under the polarizing microscope the crystals show parallel 
extinction and, in convergent light, an acute bisectrix normal to 
a, 100. The plane of the optical axes is the base. The diver- 
gence of the axes is large, the hyperbole opening out beyond 
the field of the microscope. The axes of elasticity are: 


ie b=4, =) 


The double refraction is therefore positive. 

The change which the crystals undergo when exposed to 
dry air is a molecular rearrangement, accompanied by loss of 
water and, probably a change to the anhydrous salt which was 
described above. This rearrangement is a beautiful sight when 
studied with the microscope in polarized light. The change 
commences a few minutes after the crystals are removed from 
the mother liquor, and in less than ten minutes has usually 
advanced to such an extent that the crystals are no longer 
transparent. The crystals at first show a uniform action on 
polarized light, then from different parts of the surface the 
rearrangement, which is marked by aggregate polarization, 
commences. It advances, shooting out in various directions 
in a manner resembling the growth of ammonium chloride 
crystals under the microscope, until the whole field is covered 
and light is finally no longer transmitted. 

Shettield Scientific School, April, 1892. 


H. L. Preston—New Meteorite from Kentucky. 168 


Art. XXII.—Preliminary Note of a New Meteorite from 
Kenton County, Kentucky; by H. L. Preston. 


[Read before the Rochester Academy of Science, June 27th, 1892.] 


On May 15th, Prof. Henry A. Ward received a letter from 
Mr. R. H. Fitzhugh, Bryson City, N. C., telling of a meteorite 
he had identified in Kenton County, ‘Kentucky. In Prof. 
Ward’s absence Mr. Frank A. Ward sent me off the same 
night to look up the meteorite. I arrived at Bracht station on 
the Cincinnati Southern R. R., Friday morning and drove as 
far as the roads would permit toward Mr, Geo. W. Cornelius’s 
farm. He being away from home his wife showed me the 
“metal” as they called it. It proved to bea beautiful meteorite 
of the Siderite variety, 533 X356X203 millimeters (21148 
inches) in its greatest diameters, and 163-0665 kilograms (8593 
pounds) in weight. 


Kenton Co. Meteorite, one-gseyenth natural size. 


In form in certain directions it very much resembles a nau- 
tilus. - It has numerous but mostly shallow pittings ; a few deep 
pittings occur however on the side shown in the accompanying 
cut which gives a good idea of its general outline. This 
meteorite is entirely free from crust. 


164. A. L. Preston—New Meteorite from Kentucky. 


Isaw Mr. Cornelius on the evening of the next day and 
obtained from him the following facts in relation to the 
meteorite. ; 

About the middle of August, 1889, while cleaning out a 
spring situated at the head of a gully some three-quarters of a 
mile from his present home in Kenton County, eight miles 
south of Independence, the county seat, he struck with his hoe 
something that had a metallic ring ; obtaining assistance he took 
the mass out, finding that it was interlocked in the roots of an 
ash tree from thirteen to fourteen inches in diameter and was 
between three and four feet below the normal surface. 

He let the mass lie by the spring until August, 1890, when 
he removed it to his woodshed where it has lain until purchased 
by me for the Ward collection of meteorites. It is now at 
our establishment in Rochester, N. Y. 

For the following analysis of this meteorite I am indebted 
to Mr. John M. Davison, of the Reynolds Laboratory, Univer- 
sity of Rochester. 


| Rhee Coe ape Seay vie Be Gate te ae 91°59 
SIN sige tiie pene Tek ak ip, 7°65 
COR Sr) eee eset eee 0°84 
Cu Oy Se ie ease K saprncig Steet trace. 
Oe ce I SIE LR Pe 0°12 
fe ag lt Se MR Se TR rae eee trace 
Poo ERR Monel ices trae a griyay trace 

100:20 


In the course of a conversation with Mr. 8. J. Cornelius, a 
brother of the gentlemen of whom I purchased the meteorite, 
he mentioned the fact, that about thrée o’clock on the seventh 
of July, 1873, while returning from a picnic in this locality, 
and when within half a mile of where the meteorite was sub- 
sequently found, he heard a great rumbling in the heavens, 
which appeared to last three or four minutes and was followed 
by a quivering of the earth. As the day was clear he could 
not account for this phenomenon. I met at least seven other 
people who distinctly remembered the picnic and the “rumb- 
ling in the heavens,” and some one or two “the quiver of the 
earth.” 

Is there any connection between this date and the fall of the 
meteor ? 


Jura-Trias trap of the New Haven Region. 165 


Art. XXIIL—Additional observations on the Jura-Trias 
trap of the New Haven Region; by JAMus D. Dana. 


IN connection with my description of the south front of 
West Rock, the annexed figure of the eastern part of the ex- 
posed sandstone with a portion of the base of the overlying 
sheet of trap is introduced.* It is repeated here in order to 
~ mark from it the localities of two new observations of interest. 


(TF! TPIT, 
eT j 
4x if , 
Cay ed, Wf 
STE YY 
a SO 
Ses \ Sea 


4 


Hh NW, 


SS 
<s | \ = 
TTS Wit | Ses ee 
Su SSs NG SS 
LS Ss ss SSSa Wa Se “ 
W. sSSSsssss5 SSR > So SS RE. 


I. The exposure of sandstone represented in the above 
figure owes about eight feet of its height to the removal of 
overlying trap by the quarrymen. The trap quarry (see Plate 
VII of my former paper) extends from the point E eastward 
for nearly 140 yards. At a spot about 100 yards east of this 
point and 16 feet below it in level, the removal of the debris 
from the floor of the quarry has exposed the top of another 
ledge of upturned sandstone. The escape of the trap from 
the dike, therefore, was not along the sloping surface of the 
upper layer exposed at E, but along another about one hun- . 
dred yards farther east. 


II. About 90 feet west of the point E in the preceding 
figure, and 40 to 50 feet above the quarry-road, the talus with 
the partly concealed sandstone is crossed by a five-inch dike of 
trap. It was first observed last autumn by Professor W. O. 
Crosby. It looks from the quarry-road like a slight break in 
the steep surface. (On the phototype, Plate VII, referred to 
above, it is very faintly indicated across the bed of sandstone, 
just one inch from the sandstone point E.) 

The little dike is a branch from the underside of the main 
sheet of trap. It makes a sinuous line of outcrops extending 
westward along the talus for about 40 feet, and then disappears 
under the debris. In this distance the dip of the outcrop is 
about 18 feet ; but the true dip of the sheet is northwestward 
about 20° to 25°, as nearly as could be ascertained. Toward 
its junction with the main mass of the West Rock trap, it is 
reduced, for nearly a yard of its length, to two strands hardly 


* This Journal, xlii, 102, 1891. 


166 J. D. Dana—Additional Observations on the 


an inch thick by an intervening mass of sandstone; but this is 
only an irregularity of outflow due to the way the sandstone 
has of br eaking, like that in the Mill Rock dike described and 
fioured on page 88 of the paper above mentioned. 

“This branch dike has several points of interest. 

1. It affords new proof that the West Rock outflow took 
place under a heavy cover of sandstone and therefore was 
Jaccolithic. This conclusion was sustained, in my former paper 
(p. 103), on the ground (1) that the outflow continued to be an 
ascending one for the 500 yards of its westward flow—which 
could not have been true unless it were under a resisting cover ; 
and (2) the outflow retains a thickness of 250 feet quite to its 
extreme western limit, which it could not have done if it had 
been a subaerial, or, using a much needed new word, a sur- 
Jicial, flow.* 

But (8) under daccolithic conditions, the opening of a fissure 
in the underlying sandstone for a discharge from the lower 
part of the mass of. trap or else from the dike, would bea 
natural result. The liquid trap that was being forced up and 
onward under the repressing sandstone formation, might readily 
have made the fracture, especially when, after the lava had 
attained nearly its full thickness, a new start in its movement 
was given. Had it been a surficial stream it would have had 
no fracturing power. 

2. Other points of interest in the dike are connected with 
its constitution. (1) While the rock of West Rock is a com- 
pact, rather coarsely crystalline doleryte, and has a light blue- 
gray color owing to the abundance of labradorite with the 
pyroxene, and is ‘darker and finer but still gray at its junction 
with the sandstone, the trap of the dike is black, without lus- 
ter, and aphanitic. Moreover, (2) it is amygdaloidal or vesicu- 
lar; some of the cavities are over an inch in diameter and 
contain a lining of quartz crystals with a filling often of 
laumontite, while others are minute and filled with quartz. 
The rock is besides irregularly joited, and much ritted and 
deeply altered along the rifts by weathering. 

Examined microscopically in thin slices, the rock is fous 
to have other peculiarities. (8) Magnetite is unusually abund- 
ant in very minute grains, much more so than in the trap of 
West Rock. (4) The labradorite of the rock is in erystals of 
the usual form, but they are extremely small. (5) The gray 
pyroxenic material about the labradorite is also in minute 
grains and seldom shows color in polarized light. Further, (6) 
greenish olivine is present in crystals and groups of crystals— 
a mineral not yet observed in the West Rock trap.t 

* The word superficial is too various in its significations for the place. Swr- 


jictalis like surface jn haying its prefix the French abbreviation swr in place of swper. 
5 i Pp ip 
A full petrological description of the rock will be published later by another. 
i = I p 


Jura-Trias trap of the New Haven Legion. 167 


From the facts we are safe in concluding that the liquid 
rock of the little fissure had at its outflow the maximum tem- 
perature of the main mass; for it was from its lower portion. 
Evidence of high heat is indicated by the presence of olivine. 
For in the experiments of Fouqué and Michel Lévy, basalt 
on cooling after being for 48 hours at whzte-red fusion, “a 
temperature above the melting point of pyroxene and labra- 
dorite,” afforded ‘crystals of olivine in a brownish vitreous 
magma ;” but on cooling from cherry-red fusion sustained for 
48 hours, afforded numerous microlites of labradorite and 
augite with magnetite.* 

The olivine of the dike was made at the expense nda 
of the pyroxene ; and as ordinary olivine contains 8 to 10 per 
cent of iron protoxide and 41°5 of silica, and the pyroxene of 
West Rock trap, according to the analysis of Hawes,t 15:3 per 
cent of the former to 50-7 of the latter, some iron protoxide 
may have been set free in the process to add to the magnetite, 
besides silica to form the quartz-erystals and silicates in cavi- 
ties or fissures. 

The aphanitic texture of the trap indicates rapid cooling, 
and its vesicular character, cooling where there was much 
moisture. The temperature of the liquid trap was evidently 
too high to make chlorite from the constituents of the pyrox- 
ene. Moreover, the feldspar is not much altered notwithstand- 
ing the moisture at hand. 


This dike, from the underside of the West Rock trap-mass, 
suggests an hypothesis with regard to the origin of the low 
and narrow belt of amygdaloidal trap that runs parallel with 
the high and wide belt of compact and nearly anhydrous trap 
of the Mt. Tom Ridge, from western Meriden northward, 
keeping in close parallelism with it and bending with it east- 
ward at its southern extremity in the Meriden region. On 
Percival’s map, Plate XVI in vol. xlii, of this Journal, the 
belt is that of the series of narrow dikes lettered A 1, situated 
just west of the areas 3, 4, 5, 6, 7, 8, 9, which mark the main 
trap range. It follows the curves and variations in height of 
the main range. 

The hypothesis of Prof. Wm. M. Davis supposes that this 
low amygdaloidal belt is the outcrop of an inferior sheet of 


* Synthese des Minéraux et des Roches, 1882, p. 62. 

+ This Journal, ITI, ix, 187. G. W. Hawes obtained for the composition of the 
trap (doleryte) of West Rock (mean of two analyses): Silica 51°78, alumina 
14°20, iron protoxide 8°25, iron sesquioxide 3°59, manganese protoxide 0°44, 
wat | 7°63, lime 10°70, soda 2°14, potash 0°39, phosphoric acid 0°14, ignition 
0:63—98°89% and for that of its pyroxene: Silica 50°71, alumina 3°55, iron pro- 
toxide 15°30, manganese protoxide 0°81, magnesia 13 63, lime 13°35, ignition 1°17, 
[alkalies and loss, 1-48]=100. 


168 J. D. Dana— Additional Observations on the 


trap, parallel with that of the Mt. Tom Ridge; and that the 
two were raised together from their original horizontality 
along with the sandstone formation in which they were inter- 
calated, into a monoclinal of 20° to 25°. The apparent 
satisfactoriness of this explanation is the strongest point in 
Mr. Davis’s hypothesis. 

The parallel courses of the two unlike belts has always 
seemed to me difficult to understand. But supposing the 
Mt. Tom ridge to be of laccolithic origin, like West Rock, the 
view I still believe to be most probable for reasons I have 
stated, the new facts from West Rock suggest an explanation : 
that this subordinate amygdaloidal belt of trap was produced 
by a lateral discharge from the dike of the laccolithic 
Mt. Tom belt, when the laccolithic discharge was nearing com- 
pletion. This would account for the close relation of the two 
in position. Moreover the trap of such a dike would be sure 
to be amygdaloidal ; for the north and south line of dikes of 
the Mt. Tom Ridge, situated along the western side of the 
Connecticut valley trough, would have been, from the com- 
mencement of the outflow, a barrier to the eastward or south- 
eastward flow of subterranean waters descending from the 
north and west, so that the accumulated subterranean stream 
would have been large. To the eastward, the subterranean 
waters of the valley would have been divided up by the 
parallel trap dikes, for the hydration and vesiculation of other 
such branch dikes. 

The value of the two hypotheses as to the origin of the 
trap belts—the dike or intrusive and the monocline—can be 
tested in two ways. One I have already referred to: the 
removal of the trap debris making the long east-and-west talus 
of the Mt. Tom ridge, near Meriden, exposing the sandstone, 
as done for the east-and-west talus along the similar south 
front of West Rock near New Haven. The sandstone may 
be, as it is at New Haven, wpturned beneath the trap-mass, 
without conformability between the two rocks. If this were 
found to be the case, there would be no further ground for 
doubt as to the upturning before the outflow. 

The other method is by boring. A boring carried down 
through the sandstone at points a short distance to the west of 
the Mt. Tom ridge would pass through, if the monocline 
hypothesis is the true one, at no great depth—probably within 
1000 to 2000 feet of the surface—a layer of compact trap 200 
to 800 feet thick, and then, after a little more sandstone, a 
layer of amygdaloidal trap; and not so, if the dike theory is 
correct. This test, repeated in other parts of the Connecticut 
valley in Connecticut and Massachusetts, would give conclu- 
sive facts. 


JSura-Trias trap of the New Haven Legion. 169 


The conformability of beds in monoclines is usually proved 
to be a fact by the study of transverse sections. But in the 
ease of the trap and sandstone of the Jura-Trias area of 
Eastern America, no transverse section exhibiting such con- 
formability between the trap and sandstone has yet been made 
known by any observer. 


Ill. An emergence of the sandstone placing it more or less 
above the sea-level is necessary to render the method of 
hydration above appealed to possible. There is other evidence 
of such emergence. 

The existence of dikes of amygdaloidal trap in Hast Haven, 
and of others of compact anhydrous trap in New Haven local. 
ities, two to five miles apart, is evidence, as explained in my 
Geology, of the hydration of the liquid rock. in the former 
region while on the way to the surface; for the lava at its 
source must have been all alike. This must have taken place 
during its ascent through the sandstone; for, as shown by E.8. 
Dana, the trap of the related dikes that intersect the meta- 
morphic rocks is unusually anhydrous. The New Haven dikes 
are situated along the western slope of the Connecticut valley 
“trough, and those of East Haven toward or at its center, 
where the subterranean waters would have flowed. Hence the 
difference. But if the sandstone were wholly under the sea- 
‘level, the amount of subterranean water could not have thus 
differed, in the two regions ; and consequently, there was some 
emergence. 

If the sandstone formation was thus early emerged another 
conclusion follows. The trap of the Lake Saltonstall and 
Hartford Range (its more southern part marked EI, EI, EIII 
on Percival’s map)—which I have shown to have originated, 
in all probability from fissure-ejections subsequently to the 
upturning of the sandstone—would have made, as I long since 
explained, a barrier to the Connecticut River waters, that 
would have cut off their flow southward and determined sooner 
or later their discharge by the present Middletown-Saybrook 
outlet. (See Percival’s map.) These facts therefore bear on 
Prof. Davis’s hypothesis, and on his deductions from it as to 
denudation over the region of the Connecticut valley. 


170 Scientific Intelligence. 


SCIENTIFIC INTELLIGENCE. 


I. MiIscELLANEOUS SCIENTIFIC INTELLIGENCE. 


1. Natural Science: A monthly review of Scientific Progress. 
Each no. 80 pp. 8vo. (Macmillan & Co., London and New 
York ; 14s., post free.) —The first number of this new monthly 
appeared on the Ist of March. The four numbers thus far issued 
show that it is to be a Journal of great value to all interested in 
the progress of natural science. Its contributors are men of 
high scientific standing. The June number contains papers by 
P. L. Sclater on the Antelopes of Somali-Land, with figures; 
R. Lydekker on Recent Researches in Fossil Birds; A. Yaughan 
Jennings, on the Cave Men of Mentone, giving the results of 
recent researches and a plate; G. H. Car penter, Facts and theories 
in the development of Insects ; and others by Prof. Teall, Prof. 
C. Loyd Morgan, besides various shorter notices of recent dis- 
coveries. 

2. Catalogue of Scientific Papers (1874-1883). —Completed 
by the Royal Society of London, vol. ix, 1016 pp. London, 1891. 
—This large volume is the first of the three which will form the 
third series of the Royal Society’s Catalogue of Scientific Papers, 
embracing titles of papers published or read during the decade, * 
1874-1883. The titles are arranged under the names of the 
authors and are given with great thoroughness and accuracy ; 
this first volume contains the names from Abadie to.Gissler. The 
work, like its predecessors, is invaluable to all concerned with 
the literature of science. 

3. Eeperiments with alternate currents of high potential and 
high frequency, by Nikola Tesla. A Lecture delivered before 
the Institution of Electrical Engineers, London. With a por- 
trait and biographical sketch of the author. 146 pp. 12mo. 
New York, 1892 (The W. J. Johnston Company).—Mr. Tesla’s 
lectures delivered, in February last, before the Institution of 
Electrical Engineers in London have been republished in book 
form from the pages of the Electrical World. The author’s 
name is already identified with some very important advances in 
connection with dynamos giving alternating currents. These 
lectures give the results of his experiments with very rapidly 
alternating currents of high potential, obtained from an induction 
coil operated either by the extremely rapid oscillations of a dis- 
ruptive discharge from a condenser, or, in other cases, by a spe- 
cially constructed alternator, giving many thousand reversals 
per second. The luminous phenomena obtained are not only 
novel and highly interesting, but very suggestive as to a possibly 
more efficient means of illumination than that now in use. The 
volume is well illustrated and serves to bring the substance of 
these remarkable lectures before a much larger audience than 
that which had the privilege of hearing them delivered. 


Age Paton Dex: 


Art. XXIV. — Wotes on Mesozoic Vertebrate Fossils; by 
O. C. Marsa. (With Plates II-V.) 


THE extensive collections of vertebrate fossils from the 
Laramie now under investigation by the writer contain, besides 
those already described, many specimens of much interest, and 
some of these are briefly noticed and figured in the present 
article. The Dinosauria of this formation are of special 
importance, particularly in their relations to allied forms in 
the Jurassic, and hence some of the latter, also, are figured for 
comparison. 


Claosaurus, Marsh, 1890. 


Next in importance to the Ceratopside of the Laramie are 
the Dinosaurs allied to Hadrosaurus, and, as but little is 
really known of the skeleton in this group, some of the 
important parts are here “described, and figured in Plates I 
and III. These are mainly from a single specimen which is 
in remarkable preservation; but the remains of a second indi- 
vidual, likewise in good condition, and in some respects more ~ 
perfect, have also been used in the investigation. The species 
is Claosaurus annectens, already briefly described by the 
writer.* 

The skull will be described in a later communication. The 
number of vertebrae between the skull and sacrum is thirty, 
and all were found-.in position. ‘There are nine vertebre in 
the sacrum, thoroughly codssified with each other. The anterior 
forty-five vertebree of the tail were found in position, and in 
good preservation. 


* This Journal, vol. xliii, p. 453. May, 1892. 


172 O. C. Marsh—Notes on Mesozoic Vertebrate Fossils. 


The fore limbs are unusually small in comparison with the 
posterior, and the relative size of the two is shown on Plate II. 
The seapular arch presents many points of interest. The 
scapula is large, and so much curved that the axis of its shaft 
is nearly parallel to tbe articular faces of its lower extremity, 
(Plate II, figure 1, s). On the anterior margin, above the 
articulation for the coracoid, is a strong protuberance, with 
a well-defined facet, adapted to the support of the clavicle, if 
such a bone were present. The coracoid is very small, and is 
perforated by a large foramen (Plate LI, figure 1, ec). The 
two peculiar bones now generally regarded as belonging to the 
sternum were separate, as shown in Plate III, figure 1. 

The humerus is comparatively short, and has a prominent 
radial crest. The radius and ulna are much elongated, the 
latter being longer than the humerus, and the radius about the 
same length. The ulna has a prominent olecranon process, 
and is a stouter bone than the radius. The carpal bones were 
quite short, and appear to have been only imperfectly ossified. 
The fore foot, or manus, was very long, and contained three 
functional digits only. The first digit was rudimentary, the 
second and third were nearly equal in length, the fourth was 
shorter and less developed, and the fifth entirely wanting, as 
shown in Plate II, figure 1. 

In the functional digits (II, III, IV), the phalanges are 
elongate, thus materially lengthening the fore foot. The ter- 
minal phalanges of these digits are broad and flat, showing 
that they were covered with hoofs, and not with claws. The 
limb asa whole was thus adapted to locomotion or support, 
and not at all for prehension, although this might have been 
expected from its small size and position. 

The elongation of the fore-arm and manus is a peculiar 
feature, especially when taken in connection with the ungulate 
phalanges. It may, perhaps, be explained by supposing that 
the animal gradually assumed a more erect position until it 
became essentially a biped, while the fore limbs retained in a 
measure their primitive function, and did not become prehen- 
sile, which was the case in some allied forms. 

The pelvis is shown in Plate II, figures 2 and 8, and has 
already been described by the writer. Its most notable features 
are seen in the pubis and ischium, the former having a very 
large expanded prepubis, with the postpubis rudimentary, 
while the shaft of the ischium is greatly elongated. 

The femur is long, and the shaft nearly straight. The great 
trochanter is well developed, while the third trochanter is large 
and near the middle of the shaft, as shown in Plate II, figure 
2. The external condyle of the distal end is projected well 
backward, indicating great freedom of motion at the knee. 


O. C. Marsh—Notes on Mesozoic Vertebrate Fossils. 1783 


The tibia is shorter than the femur, and has a prominent 
enemial erest. The distal end is much flattened, and the 
astragalus is closely adapted to it. The fibula is very straight, 
with its lower end flattened and closely applied to the front of 
the tibia. The caleaneum is large, with its concave upper sur- 
face closely fitted to the end of the fibula. Of the second row 
of tarsals, only a single one appears to be ossified, and that is 
very small and thin, and placed between the calcaneum and 
the fourth metatarsal, nearly or quite out of sight. 

The hind foot, or pes, had but three digits, the second, tbird, 
and fourth, all well developed and massive. The terminal 
phalanges were covered with broad hoofs. The first and fifth 
digits were entirely wanting. 

A comparison of the limbs and feet of Claosaurus, as here 
described and figured, with those of three allied forms from 
the Jurassic, Stegosaurus, Laosaurus, and Camptosaurus, as 
shown on Plates IV and V, is especially instructive. These 
three genera have already been quite fully described and 
figured by the writer, but new points of interest have been 
made out by the recent investigation of more perfect material. 
The present figures will show more accurately some of the 
mutual relations of these early herbivorous Dinosaurs to each 
other, as well as to their successors in Cretaceous time. The 
gradual changes that can be traced from one to the other will 
be discussed in a later communication. 


Paleoscincus, Leidy, 1856. 


A new reptilian genus and species, Palwoscincus costatus, 
was proposed by Dr. Leidy in 1856 for a single tooth found by 
Dr. Hayden in the Judith Basin. This tooth was more fully 
described and figured by Leidy in 1859.* The specimen 
showed well-marked characters, and many similar teeth have 
since been found, both in the Judith Basin and in various 
other localities of the Laramie. 

A smaller species, apparently of the same genus, is not 
uncommon in the Ceratops beds of Wyoming, and a character- 
istic tooth is shown on Plate III, figure 3. This may be taken 
as the type specimen, and the species it.represents may be 
called Palwoscincus latus. The crown of the tooth in this 
species is broader and the apex more pointed than in the first 
species described, and this is clearly shown in comparing the 
present figures on Plate III with those given by Leidy. 


* Proc. Acad. Nat. Sci. Philadelphia, p. 72, 1856; and Trans. Amer. Phil. Soc., 
p. 146, pl. ix, figs. 49-52, 1859. 


174 O. UC. Marsh—Notes on Mesozoic Vertebrate Fossils. 


The tooth from the Laramie described by Cope in 1882 as 
a mammalian premolar and as the type of the generic name 
Meniscoéssus evidently belongs to the above or an 1 allied genus, 
and all three are unquestionably the teeth of Dinosaurian 
reptiles pertaining to the order Stegosawria. On Plate IV, 
ficure 1, a very small but typical tooth of Stegosaurus from 
the Jurassic is represented. The allied genus Diracodon, also 
Jurassic, has similar teeth. 


Aublysodon, Leidy, 1868. 


In the same publications above cited, Dr. Leidy also described 
and figured, under the name Deinodon, a number of teeth 
which he regarded as pertaining to carnivorous Dinosaurs, but 
later, in 1868, he made a new genus, Aublysodon, for some ot 
these teeth which differed materially in form from those known 
to belong to such Dinosaurs.* The teeth regarded by Leidy 
as characteristic of Aublysodon are represented in figures 
35-45, Plate IX, of the Transactions above quoted, and the 
best preserved tooth of this series, which Leidy suspected to 
be an incisor, is shown in figures 41-45, The latter figures are 
carefully reproduced on Plate III, figure 4, of the present 
article, and two other similar teeth are represented on the 
same plate. They all have the same characteristic chisel- 
shaped crowns, covered with a thin coat of enamel, and show 
indications of wear. 


The teeth referred by Leidy to the genus Audblysodon and 
many others of the same general character since discovered 
may be divided into the four following groups, all the speci- 
mens of whieh appear to be somewhat curved either to the 
right or left: 

(1) Large teeth (Leidy’s figures 37-40) having both edges 
crenulated, and the posterior ridge between them broad. The 
wear of the apex is apparently posterior. 

(2) Somewhat smaller teeth, but still large, one of which is 
represented in Plate III, figure 5. Faint crenulations may be 
detected on the edges. The wear of the apex is on front and 
back, and also on the side, probably the outside. The posterior 
central ridge is narrow. This tooth represents a distinct species 
which may be ealled Aublysodon amplus. 

(8) Smaller teeth with no crenulations, and the posterior 
ridge with a groove (Leidy’s figures 41-45). The wear of the 
apex is in front. These may be regarded as typical of 
Aublysodon mirandus, Leidy. 

(4) The most abundant teeth are much smaller, with no 
crenulations, and the posterior ridge sharp and not grooved. 


* Proc. Acad. Nat. Sci. Philadelphia, p. 198, 1868. 


O. C. Marsh—Notes on Mesozoic Vertebrate Fossils. 115 


The wear is in front of the apex, and on one side, sometimes 
on both sides, as in. figure 6, Plate III. This tooth may be 
taken as the type of a new species, Aublysodon cristatus. 


The fact that these peculiar teeth are apparently in pairs, 
and are in themselves more like the teeth of mammals than 
of reptiles, has long been considered by the writer an argu- 
ment for the mammalian character of the smaller forms 
at least. The large crenulated teeth described by Leidy 
strongly resemble those of carnivorous Dinosaurs, as he con- 
sidered them, but no Dinosaur teeth of this form have been 
found in position in the jaws. The next smaller size, with 
very faint crenulations, one of which is figured in Plate ILI, 
figure 5, is too large for any mammal yet known from the 
Laramie, and this is true, also, of those figured by Leidy. 

Many of the smaller teeth of this type, if considered apart 
from the others, would naturally be regarded as mammalian 
incisors, especially from the lower jaw, and the wear of the 
summits would in itself tend to strengthen this reference, if 
some of these teeth alone were considered. A number have 
been found, however, that show wear not only on the summit 
and on one side near the summit, but also on the other edge. 
This would imply, if these teeth are really. lower incisors, 
either that the rami of the lower jaw were so loosely united at 
the symphysis that motion between them was possible, so that 
the incisors could thus rub against each other, or that these 
teeth were separated so as to admit the upper opposing teeth 
between them. 

That some of these teeth are mammalian incisors there can 
be but little doubt, and this doubt can only be removed 
entirely by the fortunate discovery of a tooth in position in 
the jaw. 


Cimolopteryx, Marsh, 1889. 


_The only bird hitherto known from the Laramie deposits is 
Cimolopteryx rarus, the type specimen of which is represented 
on Plate III, figure 2. Another species, about twice the size of 
the first, is indicated by various remains, among them the cora- 
coid. This bone lacks the strong inner process near the pit for 
the scapula, which is characteristic of the smaller form. The 
present species, which may be called Cimolopteryx retusus, is 
also from Wyoming. | 


The new Laramie fossils here described and figured were 
collected by Mr. J. B. Hatcher and party, in the Ceratops beds 
of Montana and Wyoming. ‘They will all be discussed more 
fully in another communication. 

New Haven, Conn., July 18, 1892. 


176 O. C. Marsh—WNotes on Mesozoic Vertebrate Fossils. 
EXPLANATION OF PLATES. 


PLATE IL, 


FIGguRE 1.—Left fore leg of Claosawrus annectens, Marsh; outside view. c, 
coracoid; h, humerus; 7, radius; s, scapula; wu, ulna; I. first digit; 
IV. fourth digit. : 

Figure 2.—Left hind leg of the same individual; outside view. a, astragalus: ¢, 
caleaneum; /, femur; /’, fibula; 7, ilium; 7s, ischium; p, pubis; p’, 
postpubis; 7, tibia. Figures ] and 2 are one-twentieth natural size. 

FIGURE 3.—Pelvis of the same individual; seen from the left. One-sixteenth 
natural size. a, acetabulum; other letters as in figure 2. 


Puate III. 


Figure 1.—Sternal bone of Claosawrus annectens. One-eighth natural size. 
a, seen from above; 6, seen from below. 

Figure 2.—Left coracoid of Otmolopteryx rarus, Marsh. Natural size. a, front 
view; 0, inner view; c, back view; d, lower end. 

Figure 3.—Tooth of Paleoscincus latus, Marsh. a, natural size; 0b, c, d, twice 
natural size. 

Figure 4.—Tooth of Aublysodon mirandus, Leidy. Natural size. a, front view, 
with sections; 6, side view. (After Leidy.) 

Figure 5.—Tooth of Aublysodon amplus, Marsh. Natural size. a, side view ; 
b, back view; c, front view. 

Figure 6.—Tooth of Aublysodon cristatus, Marsh. Twice natural size. a, side 
view; b, back view; c, front view. : 


PLATE IV. 


FIGURE |1.—Tooth of Stegosaurus ungulatus, Marsh. a, natural size; 6, c, d, twice 
natural size. 
Figure 2.—Left fore leg of the same species. 
Figure 3.—Left hind leg of the same species. Figures 2 and 3 are one-sixteenth 
natural size. Letters as in Plate II. 


PEATE iVi. 


Figure 1.—ULeft hind leg of Laosaurus altus, Marsh; outside view. One-eighth 
natural size. 

Figure 2.—Left hind leg of Camptosawrus dispar, Marsh; outside view. One- 
twelfth natural size. 

Figure 3.—Pelvis of the same individual; seen from the left. One-twelfth 
natural size. Letters as in the preceding plates. 


SELENITE CRYSTAL, 3 FT. LONG. 

This immense crystal has recently been found in Utah and is proba- 
bly the largest ever seen in New York. It is 2 ft., 10 in. long, 8 inches 
thick, weighs 60 pounds, and is beautifully formed, the planes being 
smooth and the angles sharp. It is very perfect, remarkably so for 
such a large crystal. It is a splendid museum specimen,’ 


TWIN CALCITE. GROUP. 


Another magnificent museum specimen recently received is ai group 
of Phantom Twin Crystals of Calcite from the famous locality at 
Egremont, England. It is the finest group ever found. 


PYRITE ON BARITE. 


A novelty from the same locality in England is Barite sifted over 
with small bright crystals of Pyrite, some of it being iridescent. The 
specimens average in size 3 x 4 to 0x 6 inches; prices $1.00 to $3.50. 


ENGLISH CALCITES. 


In the same shipment from England were many of the always beau- 
tiful Calcites from Bigrigg and Stanix Mines. 


WULFENITES. 


' We have just received a new lot of beautiful orange color Wulfenite 
from New Mexico ; it presents some rare forms which look like cubes 
and like flattened square prisms. Cabinet specimens, good quality, 
50c. to-$3.50; several large groups, $10.00 to $15.00. This is the finest 
lot of Wulfenite seen in New York for several years. 


RUBELLITE IN LEPIDOLITE. 


This beautiful mineral from San Diego Co., Cal., is ENGR TNE 
attractive and everyone wants a specimen for his collection; 25c. to - 
$9.00 for good cabinet specimens ; smaller specimens 10e. to 20c. 


OTHER RECENT ADDITIONS. 


Endialyte, from Arkansas, one specimen at $5.00, the best we ye 
ever had. 

Diaspore, Chester, Mass., fine large masses $3.50 to $0.00. 

es, from Virginia, en Onaine: beautiful iridescence when 
heated, 25c. to 50c. 

Glauberite and Borax crystals, from California, 250: to d0c. 

Ulexite, from California, 35c. to $1.00. 

Vesuvianite crystals, very large, from Arkansas, $2.50 to $20.00. 

Rutile, from Arkansas, geniculated crystals and groups, 25c. to $1.50. 

Vanadinite, from Arizona, deep red crystals on matrix, 25c. to $5.00. 

Laumontite, Prasopal, Smoky Quartz, Rose Fluors, Brookite, Anatase, 
Magnetite, Axinite, Adularia, Eudidymite, Cobaltite, Stibnite, Smith- 
sonite, Sulphur, etc. 


100 pp. Illustrated Catalogue, 15c.; cloth bound, 25c.; Supplement, 2GRs 
GUESS free. 


GEO. L. ENGLISH & CO., Mineralogists, 
733 & 735 BROADWAY, NEW YORK CITY. 


CON RE NES: 


ART. XL —Relations between the Surface Pensionel OF ie t oe 
uids and their Chemical Constitution ; by C. E. Lis he 
BARGER #0550 30 =. 2 oe ee Cae 

XII.—Gold Deposit at Pine Hill, Cal.; by W. Lixpcren... 

XI.—New occurrence of Ptilolite ; by W. Cross and L, G. 

: TAKING 2222 2 oS ee ee ee ae 

Apprnpix.—N ote on the Constiention of Ptilolite tk Mor- ipa 
2 demte; by Fo W.Cuskke:.— =... 22 
XIV “ene ean of Magnesium Chloride from the Chlorides 
of Sodium and Potassium. ‘by means of i Aleohol; 

by Re BoRieds 2252s Aa ee ee ” 108 
XV.—Great Shear-zone near Avalanche Dees in the ‘Adiron-_ = 
= dacks; by J. 1. Kmper  eee 109 
XVI —Her derite from Hebron, ae by Ee L. WELLS — = 
and 3S. “ai PENFINUD 22 2 oe oe 114s 
XVIJ.—Method for the Iodometric. Determination a Nizsoe 
trates; by F. A. Goocn and-H. W. Grurner.__— =e 
~XVIII—Some Alkaline Iodates; by H. L. WHEELER, jf 

. With Crystallographic Notes; by S. L. Penrrentp -... 123 jf 

XIX.—Development of the Brachiopoda. Part IT; cby Cae 
H.Bencorr: ~(With Plate d)- 2.2 222-1222 
XX.—Some Double Halides of Silver and the Alkali-metals; 
by H. L. Wetts and H. L. Wuueter. With their | ah 

Crystallography; by S.. lL. -PENBIELD ©9222 =) eo eee 155 — 


XXI.—Cesium and Rubidium Chloraurates and ‘Browne 
- rates; by H. L. Weis and H. L. Wueener. With 


their Crystallography ; by 8. L. Penrrenp ___--_-- Abe 
XXII.—Preliminary Note of a New Meteorite from Kenton 

County, Kentucky ; by H. lL. Pruston = 22. 322 2s 163 
XXJII.— Additional observations on the ee Trias trap of 

the New Haven Region;. by J. D. Dana ___-____-- “sal Gp 
XXIV.—Notes on Mesozoic Vertebrate Fossils; by. 0. C. 


Marsu. (With Plates II-V ee eh Ae ee eee 


SCIENTIFIC INTELLIGENCE, Se ey ie 


Misilaneps Scientific Intelligence—Natural Science: A paniely review of Scien- 
tific Progress: Catalogue of Scientific Papers (1874-1883): Experiments with 
alternate currents of high potential and high frequency, by Nikola Tesla, 17 


Chas. D. Walcott, 
U.S. Geol. Survey. 


SEPTEMBER, 1892. 


— Established iby] BENJAMIN SILLIMAN in 1818. 


“AMERICAN 
JOURNAL OF SCLENCE. 


_ EDITORS ; 
JAMES D, AND a Ss DANA. 


: ASSOCIATE EDITORS ie 
| Proressons JOSIAH P. COOKE, GEORGE L: GOODALE 
Ann JOHN TROWBRIDGE, or CAMBRIDGE. 


ee necons H. A. NEWTON anp A. E. VERRILL, « OF 
New Haven, : 


cron EB BARKER, oF PHILADELPHIA. 


THIRD SERIES. 
VOL. XLIV. {WHOLE NUMBER, OXLIV:] 


NO. 261. SEPTEMBER, 1892. 


2 SEN ALA VEN, CONN:: dD Ge S-DA NES 
L892. 2 


TUTTLE, MOREHOUSE & TAYLOR, PRINTERS, 871 STATE STREET.. 
_ Published monthly. Six dollars per year (postage prepaid). $6.40 to foreign sul - 


Beaiiers of countries in the Postal Union. Remittances should be made either by 
ey orders, registered letters, or bank checks, 


hexagonal crystals in the ancient slag of the Laurium mines. It was collected 
by Mr. English during his recent visit to Greece, at which time he exhaustively — 
examined all of the available slag. Notovera dozen specimens all told have been 
discovered,and the mineral will rank as one of the very rarest species. Customers 
desiring specimens should apply to us by return mail. ae 


OTHER LAURIUM MINERALS. 


A yery careful chemical examination has just been made of our rich stock ore re: 
the Laurium minerals formed by the action of the sea water on the slag of the 
Laurium mines during the 2300 years since the age of Pericles. The labeling of — 
such specimens in the past by other mineralogists was so inaccurate that we feel ~ 
sure our customers will appreciate the efforts we have put forth at great expense 
to haye all our specimens absolutely correct. Among the Laurium species which 
we can now supply are the following: Penfieldite (mew), Fiedlerite, Laurion- 
ite, Phosgenite, Anglesite, Cerussite, Selenite. All of these are se 
suited for microscopic work. 


BEAUTIFUL PREHNITES FROM PATERSON. 


A new find of unusually choice specimens from Paterson, N. J. Delicate green, 
very beautiful, crystallization well defined. The best Prehnites we have ever had — 
in stock. 


RADIATED RUBELLITE IN WHITE LEPIDOLITE. 


A most pleasing combination of these two. pretty minerals in the many ‘California 
specimens we now have displayed. 


YELLOW AND RED WULFENITES. 


Several recent shipments from the Southwest supply the best yellow Wulfenites 
we have ever had and some very good red Wulfenites both in loose crystals and 
matrix specimens. 


SARDINIAN MINERALS. 


A yery good line of these rare minerals was secured by Mr. English during his: 
recent European tour and this has been recently enriched by a new shipment 
_ giving us fine Phosgenites, RES SS: Cerussites, Ullmannites, ete. ~ 


A NEW SHIPMENT FROM ELBA. 


The immense stock of fine Elba minerals secured during Mr. English’s week’s . 
visit to the great iron mines and the famous Tourmaline localities, was replenished 
during August by another large addition. Fine Castorite crystals, Ilvaite erys- 
tals and White Beryls, superb Hematite and brilliant oe groups and — 
erystals, including many Pyrite twins. ie 


OTHER EUROPEAN MINERALS. 


We have the largest and best stock of European minerals in existence. Our 
wonderful variety ‘of such things as Hauerite, Meneghinite, Boleite, Sul- 
phur, Vesuvian minerals, Baveno minerals, Carrara Quartz, St. Gott-— 
hard and Binnenthal minerals, “Harz Mt. specimens, Scandinavian 
rarities, etc., etc., is too well known by our customers to need further comment. 


100 pp. Illustrated Catalogue, 15dc.; cloth bound, 25c.; Supplement, Re. ; 
“Cir culars free. 


GEO. L. ENGLISH & CO.,, Mineralogists, 
733 & 735 PECANS, NEW Tek CITY. 


THE 


AMERICAN JOURNAL OF SCIENCE 


[THIRD SERIES.] 


Oe 


Art. XXV.—The Gulf of Mexico as a Measure of Lsostasy ; 
by W. J. McGuxz. 


ils: 


THE now venerable James Hall was one of the first geolo- 
gists to observe that areas of rapid deposition are areas of 
subsidence. When Powell extended his early surveys into 
western America he observed the converse relation, namely, 
that areas of degradation are areas of elevation: As the geo- 
detic surveys of Great Britain, India and the European conti- 
nent yielded data for determining the distribution of density . 
in the earth, Pratt and afterward Fisher and others observed 
that the sea bottoms are heavy, the continents lighter, the 
mountain ranges lightest of all. Meantime and subsequently 
the original observations were repeated and extended in dit- 
ferent iands until the observed relations were found to be 
general ; meantime also the relation of coexistence was inferred 
to be one of sequence, and thus it came to be recognized that 
mountains are high because they are light, that sea bottoms 
are low because they are heavy, that areas of degradation rise 
because of unloading, and that areas of deposition subside 
because of loading—i. e. it came to be recognized that the 
entire terrestrial crust is in a condition analogous to that of 
hydrostatic equilibrium. This subject has been profoundly 
studied by Dutton, who invented the term zsostasy to denote 
such condition of static balance in the external portion of the 
earth. . 

Am. Jour. Sc1.—Tuirp SEries, Vou. XLIV, No. 261.—Srpt., 1892, 

12 


178 = MeGee—Gulf of Mexico as a measure of Tsostasy. 


The earlier and most of the later data upon which the doe- 
trine of isostasy depends were zndzrect, i. e., they were infer- 
ences from the characters and relations of formations laid 
down, or terranes lifted and degraded, during long past eons; 
yet there is no dearth of dzrect data—i. e., data derived imme- 
diately from observation—sustaining the doctrine. 

One class of such data is found in the relation between 
tracts of deposition and earthquakes: If the earthquakes re- 
corded in history are separated into three categories of associa- 
tion, viz: (1) earthquakes associated with volcanoes, (2) earth- 
quakes associated with hot springs, and lines or zones of active 
orogeny, and (3) great earthquakes apparently not connected 
with vuleanism or orogeny—it will be found that the greater 
part of the third category have affected tracts of rapid deposi- 
tion, and commonly that after the tremor the land stood lower 
than before. Thus, the Charleston earthquake of 1886, felt 
over an area of nearly a million square miles, affected the 
Atlantic coastal plain of the United States, a tract of remark- 
able simplicity and uniformity of movement during later 
geologic times yet one of rapid and long continued deposition ; 
the New Madrid earthquake of 1811-18, felt over an area of 
certainly a million and a half square miles in central and 
eastern United States, affected a tract of exceptionally gentle 
movement and uniform geologic history, though the unloading 
ground of the great river of the continent, and the land was 
spasmodically depressed over thousands of square miles; the 
great Lisbon earthquake of 1755 originated in and affected 
most disastrously the tract upon which the Tagus drops the 
detritus gathered from a sixth part of the Iberian peninsula; 
the Kach earthquakes of 1819 and later dates devastated the 
delta of the mountain-born Indus and ieft the land some feet 
or yards lower than before, thus extending the vast watery 
waste known as the Rann of Kach; the Cachar earthquake of 
1869 similarly affected the deposition-tract of the powerful 
Ganges and Brahma-putra; the deposition-tract of the mud- 
stained Hwang-ho and the torrential Yang-tse-Kiang are notori- 
ously earthquake ridden—in short, nearly all if not all of the 
extensive non-voleanic earthquakes recorded in history cen- 
tered in tracts of rapid deposition. In some eases the data 
derived from this relation are equivocal; yet they are some- 
times apparently trustworthy. 

A second class of direct data sustaining the doctrine of 
isostasy is found in the relation between tracts of deposition 
and measured subsidence of the land or encroachment of the 
waters. If the tracts of rapid deposition are separated into 
three categories of association, viz: (1) deposition tracts within 
or near the areas of Pleistocene glaciation, (2) deposition tracts 


McGee—Gulf of Mexico as a measure of Isostasy. 179 


in or near zones of active vulcanism or orogeny, and (8) depo- 
sition tracts in generally stable regions far removed from 
Pleistocene glaciation, vuleanism and orogeny—it will be found 
that the greater part of the third category are also tracts of 
rapid subsidence or of rapid encroachment of the waters. The 
data derived from this relation, which also are sometimes 
equivocal. though often unmistakable, are of two kinds, which 
may be called respectively quantitative and qualitative; the 
first being actual measures, and the second inferences from 
analogous measured examples and from known geologic pro- 
cesses. 

A good example of the first of these kinds of data is the 
southeastern shore of North sea, which is burdened beneath 
detritus dropped from the Rhine, Maas and Scheldt, the Weser 
and the Elbe, and which has been sinking since the beginning 
of local history ; the island of Batavia, ‘inhabited in the days 
of Tacitus is drowned; Zuydee Zee was formed by an inva- 
sion of the waters about the end of the 13th century ; again 
and again towns and villages have been inundated and swept 
from the face of the earth; broad slices of ill-fated Heligo- 
land are annually devoured by the sea; the Netherland polders 
(or dike-protected lands) are maintained by artificial embank- 
ments which require raising from generation to generation 
until now cultivated fields lie 7 to 10 meters below tide level ; 
and the artificial embankments could not withstand the force 
of the waves were they not themselves protected by much 
larger natural embankments called dunes (analogues of the 
“keys” of the American coast). The measured rate of sink- 
ing along the Netherland coast ranges from 0:09 meter to 
0°75 meter per century; since 1732 the mean rate, according 
to Girard, has been about 0°26 meter per century.* The rate 
of sea encroachment on the lowlands cannot accurately be 
determined, by reason of the artificial intervention which per- 
mits cultivation of lands lying far below tide level; the rate 
of encroachment on the higher lands is measured by the 
destruction of Heligoland, which was 190 or 200 kilometers in 
circuit in the year 800, 72 kilometers in 1300, only 6°5 kilo- 
meters in 1649,+ and is decimated annually. Another exam- 
ple is the tract centering about New York bay though 
extending from Long Island sound to Chesapeake bay, into 
which is poured near ly all the sediment gathered from a many 
times larger semi-ellipse in eastern United States, and in which 
also the sinking is known to be rapid. According to the con- 
servative estimates of the late Dr. George H. Cook, the direct 
subsidence reaches and probably exceeds two feet per century. 


* Recherches sur l’Instabilité des Continents, 1886, p. 168. 
+ Ibid, p. 31. 


180 McGee—Gulf of Mexico as a measure of Isostasy. 


The encroachment of the bays and of the adjacent Atlantic 
is proportionately rapid; within the last fifty years it has 
reached half a mile in some localities, averaging a furlong or 
more, and has destroyed property amounting to millions of 
dollars. Both of these deposition tracts lie near and possibly 
within the influence of Pleistocene glaciation; yet they are 
especially significant in that the quantitative data derived from 
them are connected with and give value to data of the qualita- 
tive kind. 

Through the association of the two kinds of data on the 
Netherland and New Jersey coasts, as well as through infer- 
ence from geologic process, it is found that the most trust- 
worthy physiographic indications of subsidence are: (1) en- 
croachment of the sea; (2) wave-built breakwaters along 
lowland coasts (the “dunes” of Holland, the “keys” of 
America); (3) precipitous and talus-free or undercut cliffs 
along highland coasts; (4) estuaries at the mouths of sediment- 
bearing rivers ; and (5) natural levées along the lower courses 
of rivers, leaving low-lying and periodically flooded marshes or 
salines on either hand. These physiographic indications 
express rates, though only in a qualitative way: Thus, the rate 
of encroachment is a function of the subsidence, but is affected 
by the seaward inclination, by the obduracy of the terrane, by 
the force of the waves and currents, etc. The building of 
natural breakwaters is characteristic only of coasts skirted by 
submerged terraces or shelves; for when coasts are so condi- 
tioned the waves come in with ever increasing impetus over the 
subsiding sea bottom, constantly casting up sand to strengthen 
the barrier, and if the contiguous land is low a lagoon or 
“sound” is formed behind the barrier and widens more rap- 
idly than the barrier, is driven inland until both are finally 
overflowed and converted into open sea, when the process is 
repeated on new-made shores; and thus in a general way the 
strength of wave-built breakwaters and the width of the 
lagoons separating them from the mainland give rude measures 
of subsidence. ‘Talus-free cliffs are indeed an indication of the 
ever increasing force of the waves on subsiding coasts; yet, 
while the cliff configuration of subsiding tracts like Chesapeake 
bay and of rising tracts like Puget sound are markedly dis- 
tinct, so many other conditions affect sea-washed rock faces 
that they are useful only in exceptional cases. Again, estu- 
aries may be inherited from earlier eons, and at the best only 
indicate that subsidence outruns sedimentation, thus giving 
minimum rather than mean measures of movement. Levée- 
building, on the other hand, may represent merely diminution 
in declivity resulting from the pushing out of deltas, and on 
the whole tends to give excessive or at most maximum meas- 
ures of subsidence. 


McGee—Gulf of Mexico as a measure of Isostasy. 181 


The qualitative kind of direct data are well exemplified at 
the head of the Bay of Bengal with the adjacent Sanderbands, 
the depositing ground of two of the most potent rivers of the 
globe (Ganges and Brahmaputra), where the rate of subsidence 
—shown by the Indian geologists to. have reached over 400 
feet in recent geologic times—has not been measured, yet is 
proved to be rapid by the coastal configuration, by the estuaries 
through which the rivers embouch, and by the immense natu- 
ral levées flanking the rivers and their distributaries and 
bounding broad intervening flats, or “jhils”; they are exem- 
plified again at the mouths of the Amazon and la Plata, which 
together carry the degradation products of the greater part of 
the South American continent, and which embouch into vast 
estuaries after dividing into networks of levée-flanked dis- 
tributaries insulating extensive marshes; they are exemplified 
also about the mouth of the Indus, once supposed to be an 
area of uplift but now known to be subsiding, where the 
larger distributaries are estuarine and where the interstream 
flats are vast salines annually flooded and silt-mantled by fresh 
waters, yet always so delicately adjusted to tide level as to be 
flooded and salt-mantled by sea waters during each annual 
monsoon ; they are apparently well exemplified again about 
the northern end of Caspian sea and in the delta plains of the 
Volga and Ural, as well as about Aral sea and in the broader 
delta plains of its far-reaching affluents; they are exemplified 
also on the northern and western shores of Black sea, and still 
more notably about the Sea of Azof, which together receive 
the drainage of a third of Europe; they are exemplified, par- 
ticularly the estuaries and anastomosing levée-flanked distribu- 
taries, on the western shore of Hwang-hai (China sea or Yellow 
sea) about the mouths of the muddy rivers draining the 
eastern Himalayas and the loess-mantled plateaus of eastern 
Thibet and western China; they are strikingly exemplified at 
the northwestern extremity of Adriatic sea about the mouth 
of the levée-lifted Po, perhaps the most energetic river of the 
world in proportion to its size; and they are exemplified more 
notably than elsewhere on the globe about the shores of the 
Gulf of Mexico, the depositing ground of rivers degrading a 
fourth of the North American continent. These and other 
notable examples are summarized in the accompanying table, 
which is graphically depicted in figure 1 (p. 183). 

On reviewing these examples yielding direct yet only quali- 
tative data concerning the relation between deposition and 
subsidence, it appears that the data are of unlike value: The 
most extensive degradation tract on the globe is that of the 
Amazon, but the Amazonian detritus is partly spread over a 
vast flood plain lying at base-level, partly dropped in an exten- 


182 MceGee—Gulf of Mexico as a measure of Isostasy. 


sive estuary, and partly cast into the sea to be widely distrib- 
uted by exceptionally powerful oceanic currents; and, more- 
over, this vast river is comparatively little affected by seasonal 
freshets such as multiply the efficiency of extra-tropical streams. 


Principal Degradation Tracts of the World (exclusive of Africa, Australia and 


Northern Lands) with the Correlative Deposition Tracts. 
Degradation Tracts. Deposition Tracts. 


5 Rivers. Areas. Water Bodies. Approximate Areas, Ratio. 
sq. ™. hy : 
le PAIN AZO Nvse att cee eels 2.010% 0.0.050eAtt anti cae =e ee 2 aes ete: 
Mississippi, oe : it aq. m. 
24 Ty Cette Ce ee 1,804,737} Gulf of Mexico.(N. half) 277,592+ 64: 
sq.m. 
{ Yang-tse-Kiang 730,000 } Se : = 3 : 
3 | Hwang-ho_....715,000 § -1,445,000* Hwang-hai__._(W. pt.) ?200,000§ 74: 
ASW lsaslelata cee ars otek eee 1540.0 0esieAtil ant] classes see eeeeee 22h See hee 
(@Danubesasse— 312,000 ) 
Re ag: car Se Black sea } 
Dew Dmepers = sees 225,000 +  992,000* INGAt oo MIP eeeOaasee 172,500] 53 
[PD niesterweesae 30,000 | AZO 
{ Other rivers -_-200,000 } 
Wh Wola = Se Soce 530,000 } & ; : Ne he 
6 gael ou cbea e 110,000 5 640,000* | Caspian --___--- (N. half) 90,000] te 
PAVE Daria: sss 3i61000)) <69.)| 5 « ‘ 
‘ ’ Amu Daria _...- 260,000 ( 576,000 MM pe ciesehasbosaae= 24,000 ll 24: 
§ Ganges } ee ee . 9 oar 
8 )Brahmaputra 4 -77-----— 575.000* Bay of Bengal (N. part)? 100,000$ 52: 
Sigil dirs ey wee eerie eep ee eres 415,000* Arabian gulf __(K. part) ? 80,000§ 5 
OMe StaWawrencess-p-— eee 395,000* Gulf of St. Lawrence -_ ?50,000§ 8: 
(@Rhines 24a 87 0) 
Mlpereenen a aes 56,000 Sbaihe - 
See er ieerea MoE Od 17000 r 1/70;000*)\"Northisears22 > aaaeee= ?15,0008 114: 
Other rivers --- 10,000 J 
; Long Island sound 
( Poe ] {ee York bay | 
124 eS \ __._ 83.000¢ ~ Raritan bay $25,000¢ 164: 
| Susquehanna et al J era eay | 
_ nn ano | Chesapeake bay, et al. J 
O or et ah wo ea on ae >] G ivA * et , T 9 <) 5 
13 | Adige, ef al. 30.000 § -- - (0,000* | Adriatic._--_-- (N. part) ? 7,0008 10: 


The second degradation area in extent is that of the Mississippi, 
the Rio Grande, and their weaker neighbors, whose deposits 
not only fall into the nearly enclosed Gulf of Mexico but, by 
reason of the prevailing currents, are confined to its northern 
fraction. A portion of this degradation area is indeed sub- 
arid and only a small portion is mountainous; yet in general 
degradation is rapid—toward the Rocky Mountains because of 


* Reduced to statute miles from A. Keith Johnson’s ‘‘ Physical Atlas of Natural 
Phenomena,” 1856, pls. 16, 17. 

+ Computed by means of the planimeter from the United States Geological Sur- 
vey ‘ 9-sheet” base map of the United States. by John B. Torbert. 

¢ Computed by John B. Torbert. 

§ Estimated. 

Encyclopedia Brittanica, 9th edition. 

“| Appleton’s American Encyclopedia. 


MeGee—Gulf of Mexico as a measure uf Isostasy. 183 


OEGRADATION 
AREA 


AMAZON 


MISSISS1PPI 
RIO GRANDE 


HWANG -HO 


LA PLATA 


1,175,000 


YANG-TSE-KIANG 


DEPOSITION 
AREA 


ATLANTIC 


GULF & MEXICO 


100,000 


HWANG-HAI 


(o) 
= 
Zz 
<x 
as 
b 
< 


DATIC EP ug ivi 
pecraoation _otrosition high declivity, 


AREA 


over the Plains 
by reason of 
late Tertiary 
elevation, in 
the northern 
bad 1h() IP LVI. loves 
cause of the 
easily eroded 
late  Pleisto- 
cene drift, in 
the Cumber- 
land plateau 
and the west- 
ern Appalach- 
ians by reason 
Oates Wartre 
SYR DARIA Tertiary eleva- 
AMU DARIA tion to which 
the streams are 


DANUBE 
ONIESTER 
ONIEPER 
DON 

OTHER RIVERS 


LACK smo AZ OF 


376,000 24 5b 24,000 5 


not yet adjust- 
Z ed, in_ nearly 
o a 
ey) hal patsy bony 
GANGES > JES ene eh ot 
BRAHMAPUTRA a) seasonal storms 


or vernal snow- 
melting; in- 
deed by far the 
greater part of 
the area stands 
so high above 
base-level that 
the activity of 
degradation is 
fairly compar- 
able with that 
of the other 
great tracts of 


dhe the globe. In 
the third degra- 
on ae dation tract in 
extent (that of 
the Hwang-ho 
and Yang-tse- 
Kiang) unload- 
_ ing is unques- 


tionably  pro- 


ARABIAN 


ST LAWRENCE 


395,000 S:1 30,000 


SH NORTH? 
3 


NEW YORK BAY 


+ 
° 
re) 
° 


H 
63,000 a 


Sf ADRIATIC 


S 


184 McGee—Gulf of Mexico as a measure of Tsostasy. 


ceeding rapidly, but the correlative area of loading is so ill-de- 
fined as hardly to be susceptible of estimate ; while in the fourth 
area (that of la Plata), where degradation is ‘probably more slug- 
gish, the deposition area is still more indefinite. The fifth in ex- 
tent of the degradation tracts concentrates its detritus in the well 
defined area of Black and Azof seas; yet so little is known of the 
coastal configuration of these seas and of the possible influence 
of Pleistocene glaciation and contiguous orogeny that the data 
afforded by this example are of ttle service. ‘The deposits of 
the sixth degradation tract are in like manner concentrated 
upon a limited area which may be assumed to equal the north- 
ern half of Caspian sea, and in the seventh tract the concen- 
tration is still greater, the degradation tract tributary to the 
Aral being no Tess than tw enty-four times that of deposition ; 

but both ‘examples are enclosed basins in which the record of 
isostatic subsidence is complicated by the direct displacement 
of the water and also by the variations in water-volume depend- 
ing on climatal conditions, and accordingly the data in these 
cases are unworthy of trust. The eighth degradation tract 
(Ganges and brahmaputra) is especially noteworthy by reason 
of the activity of the rivers and the vast volume of detritus 
annually discharged; but the correlative deposition area is so 
ill defined that, apart from the incomplete measurements of the 
Indian survey. the relative value of the data afforded by this 
example is not easily ascertained; and this is true in still 
stronger measure of the ninth tract, or that of the notably 
active Indus. The tenth degradation tract in extent (St. 
Lawrence) is useless as a measure of isostatic subsidence, (1) 
because it is wholly within the area of Pleistocene glacia- 
tion, (2) because the correlative deposition tract is ill-detined, 
and (3) because its course is interrupted by several settling 
basins. The eleventh tract (that of the Rhine and its neigh- 
bors) is one of activity in both degradation and deposition, and 
one moreover in which the combined effect of tides and cur- 
rents probably tends to confine deposition to the comparatively 
narrow zone along which subsidence is best marked, if not 
chiefly to Zuyder Zee and the riparian estuaries ; yet it is possible 
if not probable that this area is within the influence of Pleis- 
tocene glaciation, and hence of an extraneous disturbance of 
equilibrium not yet completely restored. The twelfth tract, 
too (New Yorkand neighboring bays), lies partly within the area 
of glaciation, and is moreover affected by a modern displacement; 
but it acquires value from the connection with rude yet useful 
rate measurements. The smallest of the degradation tracts (that 
of the Po, the Adige, the Piave, and several smaller streams, 
all of great activity), concentrates its products in a presumptively 


MeGee—Gulf of Mexico as a measure of Isostasy. 185 


limited portion of Adriatic Sea; yet the value of this example is 
diminished by reason of the vulcanism and orogeny of contigu- 
ous territory. For similar reasons and because of its irregularity 
of outline and inequality of loading in different parts, the 
Mediterranean may be excluded from the list of noteworthy 
deposition tracts of the globe. The African and Australian 
degradation tracts may also be neglected, partly because the 
areas are ill determined, partly because deposition is seldom 
concentrated in measureable tracts. 

Weighing the various considerations affecting the value of 
the data yielded by each of the tabulated deposition tracts, 
they appear to fall into the following order: (1) Gulf of Mex- 
ico, (2) North sea, (83) New York bay, (4) Bay of Bengal, (5) 
Adriatic sea, (6) Hwang-hai, (7) Black and Azof seas, (8) Ara- 
bian Gulf, (9) the Amazon estuary, (10) la Plata estuary, (11) 
Caspian sea, (12) the Aral, and (18) Gulf of St. Lawrence. 
On reviewing the data yielded by the several examples in 
view of this weighing, in view of the ratios between areas of 
degradation and areas of deposition, and in view of the relative 
activity of the several rivers, the influence of tides and cur- 
rents, etc., it appears that all are consistent—that every con- 
siderable deposition tract beyond the reach of Pleistocene 
glaciation, vuleanism, and orogeny is subsiding; that, other 
things equal and so far as the data are available and trust- 
worthy, the rate of subsidence is proportional to the relative 
areas of degradation and deposition; and that, other things 
equal and so far as the data are available and trustworthy, the 
subsidence is proportional to the activity of the rivers in the 
correlative degradation tracts. 


So the indirect data concerning isostasy, derived through 
inferences from formations deposited or terranes degraded 
during long past eons, are supplemented by a trustworthy 
body of direct data derived from the physiography of the 
earth in its present condition; and the direct data are superior 
to most* of the indirect in that they are susceptible of relative, 
and in some eases absolute, evaluation. 


JUL 


Even on casual inspection it is apparent that the Gulf of 
Mexico is one of the most fortunately situated deposition tracts 
of the globe for the measurement of isostatic subsidence; for 
it is a land-rimmed basin of considerable area, connected with 
open sea through relatively narrow straits, and fed by drainage 


* In one case the indirect data have been evaluated. This is Gilbert’s classic 
study of the strength of the earth’s crust as indicated by the deformed shore lines 
of the extinct Lake Bonneville (Bull. Geol. Soc. Am., vol. i, 1889. pp. 23-27; 
Monograph I, U. 8. Geol. Survey, *‘ Lake Bonneville,” 1890, p. 387, et seq.). 


186 MecGee—Gulf of Mexico as a measure of Lsostasy. 


from a many times larger degradation tract (figure 2). On 
closer inspection the first impression is strengthened: The 
northern half of the Gulf with the adjacent lands (of which 
alone the geologic history has been clearly read) is a province 
of simple structure, of limited and uniform continental move- 
ments since the middle Cretaceous; furthermore, it is this 
northern half of the Gulf which receives the drainage from 
the second largest degradation tract of the globe; moreover, 
one of the strongest oceanic currents of the globe—the main 
Atlantic equatorial current—enters the Gulf through Yucatan 


2 


) 
b 


SSa 


SS 


SS 


a8 
S 
sutnaauelin 
> 
SS 


ASS 


f Hii 
nin 
i 
vill 
is 


WN 
\ 


ii fi 


y. AM if f 


Zs ) 
\ 
NG ch INGE 
% SY 


= est } 
SSMWSLS 7 
a 


a ( : 
J.B -Torber 


channel and sweeps through the basin in such fashion as to con- 
centrate the sediments upon a narrow zone skirting the northern 
border of the basin; and finally the influence of sedimentation 
is not confined to a single delta but is so distributed that the 
rate of deposition is variable in different parts of the littoral 
zone, though in simple and easily ascertained fashion. 
Unfortunately the Gulf coast has only recently been sur- 
veyed with precision, and the surveys have not yet been re- 
peated in such manner as to give quantitatively exact meas- 
urements of land-subsidence or sea-encroachment; but the 


Sy 


RVG 
RRS NNS 
SSAWWTSN 


N 
NS 


VYCt 


RSS 
Degradation area tributary to 

Gulf of Mexico 
Deposition area of Gulf of Mexico WY 
Degradation area tributary to WY) 
New York bay, et al. 


Eraweesy 


McGee—Gulf of Mewico as a measure of Isostasy. 187 


physiographic indications of land-subsidence are numerous, 
consistent, and unmistakeable. Thus, island after island along 
the Louisiana coast has been submerged bodily or devoured by 
slices, and many historic plantations on the shores of Missis- 
sippi sound and the open Gulf have melted into the waters 
within the present century; thus, too, the coasts (with one or 
two most significant exceptions) are skirted by wave-built 
breakwaters separated from the mainland by long narrow bays 
(the “keys” and “sounds” of the vernacular) from the Rio 
Grande to Florida strait; again, wherever the generally low 
coastward lands rise a dozen feet or yards above tide, they are 
carved into precipitous talus-free cliffs; half of the rivers, too, 
albeit heavily detritus-charged, embouch into estuaries; and, 
moreover, each principal river, whether estuarine or delta- 
building toward its mouth, divides into distributaries (or 
‘“bayous”’) in its lower reaches, and the anastomosing channels 
are flanked by natural levées separating periodically-inundated 
flats, which are lakes, marshes, salines, or “ black prairies” ac- 
cording to local conditions. In addition to these physiographic 
data there are found buried forests, old causeways now over- 
flowed at low tide, aboriginal shell heaps nearly or quite sub- 
merged, savanna pine forests once Inxuriant but now poisoned 
by salt water, and various other indications of changing rela- 
tion between land and sea; and it is to be observed that while 
these indications vary in strength they are all consistent in 
direction—all point to subsiding land, none point to rising or 
even stationary land. 

On comparing the physiographic data about the shores of 
the Gulf with the like data yielded by measured examples of 
New Jersey and the Netherlands, it would appear, (1) that the 
average rate of sea-encroachment about the Gulf is nearly or 
quite as high as on the New Jersey coast and higher than on 
the Netherland coast, at least since the building of the dikes ; 
(2) that on the average the wave-built breakwaters are higher 
and more distant from the mainland than in New Jersey, and 
more extensive than, though scarcely so high and distant as in 
the Netherlands; (3) that the talus-free cliffs are even more 
characteristic than in New Jersey or (probably) the Nether- 
lands ; (4) that on the average the estuaries are nearly as broad 
and deep as in New Jersey and more extensive than in Hol- 
land: and (5) that the natural levées are relatively higher and 
broader than in New Jersey and, so far as comparison is possi- 
ble, about as high and broad as in the Netherlands. The value 
of the physiographic indications of subsidence of course de- 
pends largely on a number of local and general conditions, such 
as volumes of rivers, height of tides, strength of oceanic cur- 
rents, direction of prevailing winds, the material, height, and 


188 McGee—Gulf of Mexico as a measure of Tsostasy. 


general configuration of shores, the breadth and depth of the 
water-body in which the waves are generated, ete.; yet howso- 
ever these conditions affecting the comparison are weighed, the 
Gulf phenomena appear to record an average subsidence fully 
as rapid as that of the Netherlands or New Jersey; or (the 
vertical movement in the carefully measured case amounting 
to 0°26 meter and in the more roughly measured example 
reaching two feet per century) of at least a foot in a hundred 
years, 

: On comparing this value with the rates of degradation and 
correlative deposition, a relation is obtained which, although 
lacking in precision, is nevertheless useful: The area of deg- 
radation is 1,800,000 square miles; the maximum assignable 
area of deposition is less than 300,000 square miles, and since 
the direction and force of currents and the configuration of the 
Gulf bottom alike indicate that appreciable sedimentation 
must be confined to a relatively narrow zone skirting the coast, 
it may be placed at a third of that area or 100,000 square 
miles, which is one-eighteenth that of degradation. Now, the 
commonly accepted rate of degradation of the earth’s surface, 
based on the surveys of the Mississippi by Humphreys and 
Abbot, is a foot in 6000 years; and this corresponds to deposi- 
tion within the Gulf reaching one foot in 333 years. So it 
would appear that the average rate of subsidence deduced from 
comparisons with New Jersey and the Netherlands is three 
times higher than would be required for isostatic adjustment ; 
and although the various factors are so uncertain (probably 
Humphrey’s and Abbot’s value and the deduced rate of sub- 
sidence are too low and the assumed deposition area too high) 
that the estimate is subject to a “probable error” perhaps 
large enough to explain the discrepancy, the discrepancy never- 
theless suggests that a part of the subsidence may be due to 
some other cause. This suggestion derives strength from the 
indications of general subsidence along the contiguous Atlantic 
coast of the United States. 

On comparing the local physiographic indications of subsi- 
dence at various points on the Gulf coast, a noteworthy diver- 
sity is found. Thus, the most decisive historical records of en- 
croachment come from the Louisiana and Mississippi coasts, and 
there, too, talus-free cliffs are most characteristic. Again the 
strength of keys and the width of sounds varies widely; along 
the Florida coast, despite the long sweep of storm winds and 
trades, the keys are weak, the sounds narrow and shoal; toward 
the Appalachicola and Mobile bay the keys strengthen and the 
sounds widen, save where dammed by deltas; west of Mobile 
bay the keys are huge but half submerged banks rising in a 
line of islands separated from the mainland by the broad Mis- 


McGee—Gulf of Mexico as a measure of Isostasy. 189 


sissippi sound; west of the great delta the corresponding keys 
are completely submerged and reduced to a series of banks and 
shoals separated from the mainland by a trough even broader 
than Mississippi sound, and new keys and sounds are forming 
along the present coast ; southwest of Galveston bay the keys 
are of unparalleled strength and continuity, while the sounds are 
broad and scores or even hundreds of miles in length. More- 
- over, some rivers are estuarine while others are delta-builders, 
and this difference in habit is evidently independent in large 
‘measure of stream-volume and of sediment. Yet on careful ex- 
amination, the apparent discordance falls into harmony: The 
strength of keys and width of sounds is least in the eastern 
part of the embayment where the sediment-bearing rivers are 
relatively short and feeble, greater in the northwest where the 
rivers are longer and more potent, and greatest about the de- 
positing ground of the chief river of the continent. So, too, 
all the large rivers of the western and eastern coasts are delta- 
builders ; while all of the extra-Mississippi streams within a 
hundred or a hundred and fifty miles of the great river (and 
presumptively within reach of its isostatic influence) embouche 
into estuaries.* This harmony is suggestive, if not precisely 
indicative, of a quantitative relation between local deposition 
and local subsidence. 

Summarily, the Gulf of Mexico, considered as a unit, is one 
of the most fortunately situated deposition-tracts of the world 
for yielding a measure of isostatic subsidence; considered 
again asa unit, its shores appear to be subsiding quite as 
rapidly as isostasy demands; and considered as an assemblage 
of deposition sub-tracts, the varying rates of subsidence appear 
to be delicately adjusted to the local rates of deposition. 


So the data relating to the condition of the earth’s crust 
derived from the modern Gulf of Mexico indicate that through- 
out the vast geologic province of southeastern North America, 
isostasy is probably perfect, i. e., that land and sea bottom are 
here in a state of hydrostatic equilibrium so delicately adjusted 
that any transfer of load produces a quantitatively equivalent 
deformation.t 


* These features are set forth at some length in a paper on the Lafayette for- 
mation, 12th Ann. Rep. U.S. Geol. Survey. 1892, pp. 347-521, pls. xxxii—xli. 

+ Thomson and other physicists concluded some years ago, after a study of the 
tides, precession, etc., that the earth as a whole must be as rigid at least as steel. 
Newcomb has quite recently concluded, after discussing new data (including 
Chandler’s brilliant coordination of the recorded variations in latitude in connec- 
tion with Oppolzer’s computations), that ‘‘the earth yields slightly less . . . than 
it would if it had the rigidity of steel, and that it is consequently slightly more 
rigid than steel” (Monthly Notices of the Royal Astronomical Society, vol. lii, 
no. 5 (1892), p. 339); so that while Thomson’s result gives a minimum value, 
that of Newcomb gives a maximum value for the rigidity of the earth as deter- 
mined from cosmic relations. Now, without analysis of the differences in defini- 


190 MeGee—Gulf of Mexico as a measure of Lsostasy. 


Til. 


The measure of isostasy found in the modern Gulf of 
Mexico might be tested by comparison with the measures 
yielded by ‘other gulfs and bays, were the data concerning the 
several fortunately situated deposition-tracts sufficiently pre- 
cise; but mm the dearth of surveys and bench-marks it must 
suffice to repeat that the physiographic data afforded by the 
Bay of Bengal, the Adriatic, Hwang-hai, Black and Azof seas, 
the Arabian oulf, the mouths of the Amazon and la Plata, 
ete., are harmonious therewith. The measure cannot well be 
tested by comparison with the indirect data derived from study 
of ancient formations or terranes in other geologic provinces, 
since most of such data are isolated and, by reason of ignorance 
concerning the absolute or relative areas of the tracts of degra- 
dation and deposition respectively only rudely qualitative, and 
since in the single case in which the indirect measure is quanti- 
tative—Gilbert’s ancient Lake Bonneville—the problem is so 
complex as to permit only the statement that the results are in 
a general way harmonious with the data yielded by the modern 
Gulf, The measure may, however, be checked by comparison 
with past records of the geologic province represented by the 
Gulf and adjacent lands. 

The later geologic history of the Gulf of Mexico is now 
fairly well known. The uppermost structural unit of the con- 
tiguous land area is the early Pleistocene Columbia formation ; 
the next in age is the late Neocene (probably Pliocene) Lafay- 
ette (Appomattox) formation. Now the history recorded in 
these formations and in the unconformities by which they are 
bounded may be thus interpreted: Before the Lafayette period 
the configuration of the southeastern quarter of the continent 
was much the same as to-day, save that the land lay somewhat 
lower and flatter; then came the Lafayette inundation, 300 to 
900 feet in depth and extending from 100 to 500 miles inland; 
this was followed by a high level period during which the land 
was tilted seaward from the Appalachian axis but lifted 300 to 
1000 feet higher than before (or now), and during which half 
of the volume of the Lafayette formation was degraded, while 
the rivers carved broad and deep canyons forming the estuaries 
yet indenting the Atlantic and Gulf coasts; next the land 
gradually subsided to its previous (and about the present) mean 
tion of terms to which are due the apparent discordance between the current 
doctrine of physics and that of geology, it may be pointed out that these re- 
markable and admirable inductions of physics have no more to do with the 
deformation dealt with by geologists than laboratory experiments on the rigidity 
and brittleness of ice have to do with the movements of glaciers; and the 


mobility of the terrestrial crust through a range reaching thousands of feet and 
even miles is now quite as well established as is the mobility of glacier ice. 


MeGee—Gulf of Mexico as a measure of Isostasy. 191 


altitude, though the relative lifting of the Appalachian axis 
persisted; then came the Columbia inundation, which was 
coeval with the first known ice-invasion, during which the 
Atlantic and Gulf again united and flowed inland 20 to 500 


Columba Fall line Gorpe-cutling Trenton. 


wn ee 


Pleistocene 


Neocens 


Ss 


alachtan Gorgs-cuttt 
Pp: gs: Lae’ 


Piedmont A, 


ao 4 


ees 


~ 
ES 
3 
g 
3 


2 


== 


\ 


Presont Sea Level 
aS 


tEarly glacial, aInterglacial. 3Late glacial, +Pastglacial 


miles, rising 100 to 700 feet above their present 
level; finally the land rose so high as to permit 
the excavation of the submarine channels of the 
Hudson, the Delaware, the Susquehanna, the 
Potomac and the Mississippi, but soon subsided ; 
and this last subsidence of the southern land 
seems to have been little affected by the later ice 
invasions, and is perhaps, even probably, yet in 
progress. These oscillations are represented 
graphically in the accompanying diagram (figure 
3) in which the ordinates represent time, the 
abscissas continental altitude.* 

On comparing, or rather contrasting, these 
great continental oscillations with the gentle 
modern movement along the shores of the Gulf, 
they are found to differ widely: The modern 
subsidence appears to be a gentle warping in such 
direction as to deepen the basin and gradually 
submerge its perimeter; the old oscillations were 
widespread and involved both sea bottom and 
continent. The modern movement is slight and 
commensurate with the simple and uniform: 
processes of degradation and sedimentation ; the 
old movements were cataclysmic, and utterly 
transcended the influence of rain and rivers— 
they were indeed of greater amplitude than any 
other continent movements of southeastern North 
America since the close of the Cretaceous. 

Now the modern movements not only yield a 
quantitative measure of isostacy (with a ‘ prob- 
able error”? whose value is indeterminate) but 
give a rude measure of the efliciency of degrada- 
tional transfer of matter on the surface of the 
earth’s crust in producing deformation; while the 
movements recorded in the Columbia and Lafay- 
ette formations were of so much greater ampli- 
tude that they may not be referred to a similar 
cause. In this province as in others, therefore, 
it becomes necessary to discriminate the two 
classes of earth movements elsewhere called, 


* They are represented physiographically in a series of tectonic maps illustrat- 
ing a paper on che Lafayette formation now in press as a part of the 12th Ann. 
Rep. U.S. Geol. Survey (pls. xxxix—xli). 


192 ES. Ferry—Persistence of Vision. 


respectively, antecedent and conseqguent—the first including 
those grand initial movements of debatable cause by whieh 
continents are lifted and sometimes deformed or drowned, and 
the second including the more restricted movements due to 
loading and unloading. 

So the modern province measures the competence of isos- 
tasy, the ancient province its incompetence ; the modern Gulf 
illustrates the magnitude, the ancient Gulf the minitude, of 
isostatic deformation as a means in continent making. 


VE , 


Recurring now to the direct and indirect measures of isostasy 
afforded by “the Gulf of Mexico in its present condition and 
past history, it may confidently be concluded: (1) that the direct 
data of modern times indicate that deposition and isostatic sub- 
sidence are not only related sequentially but that under favor- 
able conditions they are quantitatively equal or sub-equal; (2) 
that this measure of isostasy is consistent with the direct data, 
both quantitative and qualitative, yielded by other noteworthy 
deposition tracts of the globe; and (8) that the indirect data 
afforded by the Gulf indicate that isostatic (or consequent) 
movement alone is incompetent to explain the general conti- 
nental oscillations recorded in the Neozoie deposits. Thus the 
Gulf of Mexico yields both maximum and minimum measures 
of isostasy. 


Art. XX VI.— Persistence of Vision; by ERvin 8. FERRY. 
{Contributions from the Physical Laboratory of Cornell University, No. 10.] 


EVER since the time of Aristotle, it has been known that 
when the eye is impressed by light, the sensation persists even 
after the exciting cause bas ceased to act. In his work on 
dreams, Aristotle describes duration of impressions in the 
retina and then deduces as the cause of dreams a similar per- 
sistence of impression on the sensorium of things experienced 
when awake. The ancients noticed and correctly explaimed 
many optical illusions by persistence of vision; but it was not 
till twenty centuries after Aristotle that anyone attempted to 
measure the duration cf visual impression. Segner* measured 
the duration of the light impression from a spark of a rotating 
stick and adopted 0:1 second as the probable value. D’Arcy,t 


* De raritate luminis (Gottingen, 1740, pp. 5-8). 
+ Mémoire sur la durée de la sensation de la yue (1768). 


ES. Ferry 


Persistence of Vision. 193 


Cavallo,* and Parrott+ have since fully substantiated this value 
by accurate measurements. Plateau,t in 1829, found that when 
dises divided into sectors alternately black and of some special 
color were rotated, different speeds were Req Ee. to produce 
uniformity of tint, depending upon the color-of the pigment 
used to paint the alternate sectors. By noting the angular 
size of the black and the colored sectors and the speed just 
necessary to produce uniformity of tint, he was enabled to de- 
termine the absolute duration of the maximum impression for 
the different colors experimented upon. By using the differ- 
ent discs painted in sectors, each having black alternating with 
some one color, Plateau obtained the following values for the 
duration of impression for these particular colors :— 


AYAYAR Ori eye LS Re Sy i ka dt eas 0°191 sees. 
BY Gell @iyyaett Sigats Pear ae Ss ear Ch re ae RS 07199 * 
IRR GLb aes ead a ee oh RES On2 SOEs 
IBD Ve) Soom leate omnes CMR ee eee he Meo e A mes Op2 95 


One great difficulty with this method is that since no pig- 
ment gives a pure color and since pigments vary so widely in 
tint, the results obtained hold only for the particular speci- 
mens experimented upon. ‘To overcome this difficulty, Dr. E. 
L. Nichols§ employed a revolving dise having sectors cut out, 
in front of the slit of the spectroscope, and defined his colors 
by their wave-lengths. In this manner by suitably choosing 
the wave-lengths used for observation, a curve was drawn 
showing the relation between the duration of impression and 
the color corresponding to any wave-length. 

From the results obtained by Plateau, 
and others, it was reasoned that the duration of retinal impres- 
sions depends upon the intensity of the light-giving source 
and upon the color of the light entering the eye. To test the 
validity of this latter proposition, and to determine the princi- 
pal factors producing persistence of vision has been the object 
of the series of experiments now to be described. 


Apparatus and Method of Oprcruatron 


The plan of the investigation was to obtain curves showing 
the relation between duration of the retinal i impression of the 
normal eye and wave-length of light observed for spectra of 


* The elements of natural or experimental philosophy (London, 1803), vol. iii, 
p. 135. 

+ Entretiéns sur la physique (Dorpat, 1819), vol. iii, p. 235. 

t Dissertation sur quelques propriétés des impressions produites par la lumiére 
sur l’organs de la vue. (Liege, 1829). 

§ On the Duration of Color Impressions upon the Retina, this Journal, vol. 
XXVili, p. 243. 

|| Ueber die Dauer des Lichteindrucks, Pogg. Ann., xci (1854), p. 611. 


AM. JouR. Sci.—THIRD SERIES, VoL. XLIV, No. 261.—Supr., 1892. 
13 


194 ES. Ferry—Persistence of Vision. 


different intensities; to compare these curves with another 
showing the distribution of luminosity in the spectrum used ; 
and finally to compare similar curves obtained from dichroic 
eyes. 

"The apparatus for the measurement of the retinal impression 
consisted of a diffraction-grating spectrometer; a sectored dise 
that could be revolved by an electric motor, interposed between 
the lamp and collimator; and a chronograph to register accu- 
rately the number of revolutions of the disc. The source of 
light was a hundred-volt Edison incandescent lamp supplied 
by a secondary battery, and it was kept at constant candle 
power by varying the resistance in circuit so that a volt-meter 
would always indicate one hundred volts. In front of the 
lamp was mounted a large condensing lens for the purpose of 
projecting upon the collimator slit an enlarged image of the 
filament. In this way a uniform distribution of light was ob- 
tained in all parts of the field of the spectrometer. At the 
foeus of the eye-piece of the telescope was placed a diaphragm 
so as to isolate from the spectrum the single color it was de- 
sired to observe. The dise had a ninety-degree sector cut out 
from each end of a diameter so that when the disc revolved 
there would be seen in the telescope equal periods of iltumina- 
tion and of darkness. The speed of the disc was controlled by 
means of a friction-brake managed by the observer. On the 
shaft of the dise was mounted a contact device by means of 
which an electric circuit was made for an instant on each revo- 
lution of the disc. This current was conducted to the primary 
of an induction coil having the secondary so connected to a 
chronograph eylinder that a spark would puncture a blackened 
paper on the cylinder every time the sectored disc revolved. 
Pressing against the chronograph cylinder was a stylus electric- 
ally connected to the escapement of a standard clock. By this 
device the number of revolutions of the sectored dise in a 
second could be very accurately determined. 

When taking an observation, the experimenter sits at the 
telescope of the spectrometer with one hand on the brake 
regulating the speed of the sectored disc. The disc is first 
made to revolve so slowly that the field of view in the tele- 
scope flickers, and then the speed is gradually increased till the 
point is reached when the field just becomes quiet; then a key 
is pressed and an assistant rotates the chronograph cylinder for 
five seconds and takes the record of the speed of the sectored 
disc. This gives the duration of the maximum impression on 
the retina. Such a short time of observation as here used has 
many manifest advantages. Even when the disc is steadied 
by a heavy fly-wheel as was done in these experiments, and 
rotated by a powerful motor, the speed can be kept constant 
for only a short time. Other experimenters have taken one- 


s 


ES. Ferry—Persistence of Vision. 195 


minute observations or longer, and found their separate obser- 
vations differing by a large per cent from the mean. With 
this apparatus a difference of more than three per cent between 
_two observations of the same region in a spectrum of ordinary 
brightness is rare. The observations at regions of low bright- 
ness are more difficult. 

The eye was subjected to the intermittent light for as short 
a time as possible so as to avoid the secondary colors described 
by Signor Cintolesi.* After each observation on colored 
light the eye was rested by looking at white light and 
the succeeding observation was invariably made on a dif- 
ferent color. Thus the disproportionate increase of sensitive- 
ness of the eye for more refrangible rays due to adaptation, as 
noticed by M. H. Parinaud,+ was guarded against. These ob- 
servations were made in a room with blackened walls and 
every attempt was made to exclude extraneous light. It was 
also soon found that precautions were necessary to eliminate 
the slight tremor produced by the motor and the disc, because 
a vibration of the lamp or of the diffraction-grating produces 
a flicker in the field of view that cannot be distinguished from 
the appearance produced by a too slow rotation of the sectored 
dise. 


Duration of Light Impressions on the Normal Retina. 


To represent the normal eye, three persons were selected of 
about the same age, whose eyes were free from Daltonism, astig- 
matism, near- and far-sightedness and from such abnormal color 
sensations as have been recently observed by Captain Abneyt 
in confirmed users of narcotics and stimulants. How very 
closely the duration of retinal impression for each part of the 
spectrum agreed for these cases is shown in the following table: 


Wap 
Wave-length. Duration of retinal impression in seconds. 
A ELS. F. Go WaB: EK. EF. N. 
"435 "0357 0357 0353 
"480 "0250 0263 
‘510 °0200 ‘0186 ‘0200 
‘D40 ‘0156 °0152 
570 0159 ‘0139 0139 
"589 0132 °0128 °0128 
615 0141 "0142 
645 "0156 0152 
684 "0192 ‘0179 "0192 


* Ann. di Optalmol. II and III, 1879. 

+ De Vintensité lumineuse des couleurs spectrales, Comptes Rendus, xcix, p. 937. 

¢ On the Examination for Color of cases of Tobacco Scotoma, and of Abnormal 
Color-blindness, Roy. Soc. Proc., xlix (1891), p. 491. 


196 ES. Ferry—Persistence of Vision. 


The values given in this table as well as in all the succeeding 
tables are not averages of a number of observations, but are 
the values of a single set of readings. The third and fourth 
columns are the values obtained by two observers who had 
only used the apparatus for about an hour, and are hence less 
reliable than the values in the second column which have been 
many times repeated. The curve platted from the values in 
the second column is shown in fig. 1, curve 8. 


me bo 
fc) 
J 
wn 
t 


° Impressijon. 
e 


ater 


on 


Dura 


| 
210 | 


Wave |Lengthj | 


i a 
430 470 470 490 3/0 530 3350 370 590 610 630 650 670 690 


Duration of Impression of normal eye for different colors and different inten- 
sities. 


The fact was noticed with some surprise that on different 
days the observations were nearly identical, if the eyes had not 
been strained or made more than normally sensitive by re- 


ES. Ferry— Persistence of Vision. 197 


maining for a long time in a dark room. And it was also 
found that the sensitiveness of the eye might have changed 
by several per cent without producing any “noticeable differ- 
ence in the duration of the retinal impression. This shows 
two things: first, that the personal equation, or more properly 
the personal error, in this sort of investigation is less formid- 
able than ordinarily supposed ; and secondly that a compara- 
tively large change of sensitiveness of the eye is required to 
produce a marked change im the duration of the retinal 
impression. 

An examination of this curve (8, fig. 1) shows that the 
retinal persistence is very different for different parts of the 
spectrum. As in the curves published by Dr. Nichols, in the 
paper already cited, the minimum duration is near the D line, 
and from this point the duration steadily increases toward each 
end of the spectrum. The observations were carried relatively 
farther into the blue than in the red, which largely accounts 
for the apparent unsymmetrical form of the curve. The curve 
is of the general form of a parabola with its apex approxi- 
mately at the D line and the two branches becoming parallel 
to the ordinates of the ends of the spectrum. 


Duration of Retinal Impression for light of different Intensities. 


In the early part of this century Plateau* noticed that there 
was an intimate connection between duration of retinal im- 
pressions and the intensity of the light producing them. One 
of the principal objects of this investigation was to determine 
the law connecting these quantities. To do this, values of 
duration of retinal impression were obtained for monochro- 
matic light of different intensities. The lght intensity was 
varied by changing the width of the collimator slit according 
to Vierordt’s method. The plan followed was to obtain a 
spectrum of a certain brightness, and measure the duration of 
retinal impression at sufficient points in it to be able to plat a 
curve showing the relation between the retinal persistence and 
wave-length. Then changing the width of the collimator slit 
by a definite amount, so as to obtain a.spectrum of a brightness 
in known proportion to that of the preceding spectrum, to 
determine the duration of impression for the same points as 
before. In this way the following values were obtained for 
the duration of retinal impression of monochromatic light of 
different color and different intensity. 


* Dissertation sur quelque propriétés des impressions produites par la lumiére 
sur Vorgans de la vue. (Liege 1829.) 


198 ES. Ferry-—Persistence of Vision. 


TaB_e II. 


Duration of retinal impressions for monochromatic light of 
different wave-length, of relative brightness from L to 24. 


Waye- Duration of retinal impressions in seconds. 


length. 1. 2. 4. 8. 16. 24. 
“435 0357 “0294 022% 
“480 "0328 0286 “0250 0217 

“510 ‘0200 

540 "0200 °0192 ‘0172 *0156 "0133 0119 
“570 5 0139 ‘0109 

“589 ‘0170 “O161 0147 0132 “0102 ‘0081 
“615 ‘0141 “O111 

°645 0204 *0192 ‘O179 ‘0156 0130 

“684 0238 0217 -0192 0172 “0156 


These values are platted in the curves shown in fig. 1. The 
numbers affixed to the curves indicate the relative brightness 
of the spectra. 

These curves show that with increased brightness the values of 
retinal presistence do not shift their positions relative to wave- 
length; that as the brightness of the spectrum increases, the dur- 
ation becomes less in such a manner that each point in the curve 
is shifted downward by a nearly constant amount; and that the 
distance separating the different curves has a definite relation 
to the difference of the light intensity of the spectra from 
which the curves were obtained. 

If the values be noticed for the duration of impression of all 
_ the curves, corresponding to any single wave-length, it will be 

perceived that the following statement is approximately true: 
as the intensity of light increases in geometrical ratio, the 
duration of the corresponding retinal impression decreases in 
arithmetical ratio. This statement can be concisely expressed 
in the form of the approximate empirical law—the difference 
of the duration of two retinal impressions produced by two 
lights of the same color, is inversely proportional to the 
logarithm of the quotient of the respective luminous inten- 
sities. 

The value obtained for the ends of the spectrum deviate 
from this law, but this is probably due to the uncertainty of 
the observations in these faintly illuminated regions. The 
relation between duration and light intensity, thus far deals 
simply with lights of the same color. The next object of the 
experiment was to test the generality of this law, by determin- 
ing if it would hold for lights of different color. 


Relation between Luminosity and Duration of Retinal Im- 
pression. 


By luminosity is meant the physiological effect of light upon 
the eye by means of which vision is accomplished. The meas- 


LE. S. Ferry—Persistence of Vision. 199 


ure of luminosity is the amount of light necessary to enable one 
to clearly distinguish objects. The spectra of various light 
sources are so very different in the distribution of luminosity, 
that it was considered necessary to determine these values for 
the particular lamp used in these experiments. 


650 670 690 


Distribution of Luminosity in 16-candle power, 100-volt Edison Incandescent Lamp 


The method employed was to insert an object into the eye 
piece of the spectrometer and to reduce the aperture of the 
objective of the cbserving telescope by means of a tine microm- 
eter slit till the object was just visible. The reciprocals of 
the micrometer slit areas gave the relative luminosities of the 
different parts of the spectrum. This method is less conve- 
nient and possibly less accurate than the Rumford photometer 
method used by Abney and Festing* but it gave a probable 
error of only about five per cent. 


TABLE ITI. 


Distribution of Luminosity in normal spectrum of a 16 C. P. 100 volt Edison 
Incandescent lamp—Platted in Fig. 2. 


Wave- Relative Wave- Relative 
length. luminosity. length. luminosity. 
“435 1°86 “589 100°00 
“455 3°06 “615 83°25 
480 13°89 645 54°37 
“a10 28°28 675 ei 
"540 50°00 HB 4 11°16 

570 89°25 


* Colour Photometry, Trans. Roy. Soc. Lond., 1888, p. 547. 


200 ES. Ferry—Persistence of Vision. 


The form of this curve suggested the possibility of lumin- 
osity bearing a reciprocal relation to duration of impression. 
This idea was tested in two ways. First, one particular region 
in the spectrum was chosen and its luminosity varied so as to 
be equal to the luminosity of different parts of the normal 
spectrum as given in Table III; the duration of retinal 
impression was then measured for these luminosities and gave 
the following values: 


TABLE IV. 


Duration of impression for a single color having its luminosity varied so as to 
equal the luminosities of different parts of the normal spectrum. 


Corresponding to Given duration of 
Relative luminosity. wave-length. impression in seconds. 

1°86 435 °0358 
13°89 ‘480 0227 
28°28 510 "0200 
50°00 "540 ‘0161 
89°25 = HO 01438 
100°00 "589 ‘0138 
83°25 615 0143 
54°37 “645 “0161 
11°16 ‘684 °0192 


The luminosities taken in this table are the same as in the 
normal spectrum that gave the values in the fifth column, 
Table II. A comparison of the third column, Table IV, and 
the fifth column, Table II, indicates that luminosity is the 
important factor in persistence of vision. To farther test this 
* deduction, observations were made on the duration of impres- 
sion for different colors of the normal spectrum, when each 
color was brought to the same luminosity. If the above 
deduction is valid, then if each color is brought to the same 
absolute luminosity, the retinal persistence of each color will 
give the same value. The values obtained are given below. 


TABLE V. 


Duration of impression when each spectral color is brought to the same 
luminosity. 


Wave-length. Duration in seconds. 
‘O10 ‘O151 
‘540 “O147- 
570 °0149 
589 “0147 
615 0147 
*645 ‘O147 


Duration of Light Impressions on Color-Blind Eyes. 


Asa still farther test of the theory that retinal persistence 
is practically independent of color but depends principally 


ES. Ferry—Persistence of Vision. 201 


upon luminosity, duration of impression curves were obtained 
from dichroic eyes. It is well known that a color-blind person 
not only lacks one of the fundamental color sensations but also 
that he perceives other colors differently from the normal. 
For instance, according to Holmgren,* in the spectrum as seen 
by red-blind persons yellow begins at about line C and extends 
an orange, yellow and yellowish green and ends near F. At 
this neutral zone the blue begins and extends to the end of the 
normal spectrum. If now duration of retinal impression does 
depend in any way upon color, one would expect that the 
curves obtained from color-blind persons would differ from 
those of the normal in a way that could not be explained by 
considerations of luminosity alone. An examination of about 
two hundred members of a large class in physics, by Holm- 
gren’s worsted method furnished eight cases of color-blindness, 
one being red-blind, the remainder being green-blind. The 
proportion of color-blind in even this limited number was 
about the same as found by Dr. Jeffriest from the examin- 
ation of 175,000 persons. 

These color-blind students were examined for the neutral 
point by the method of A. Koenigt which consists in deter- 
mining the color that they will match with white or gray. A 
prism having one face coated with magnesium white was so 
mounted in the Helmholtz color-mixing spectroscope, that a 
ray of light from the collimator passing through the prism 
would be dispersed into a spectrum, while a ray from a second 
source falling on the white surface would be reflected directly 
into the telescope. If now the eye-piece of the telescope be 
removed, one-half the field of view will be filled with color and 
the other half with pure white or gray. With this arrange- 
ment a color-blind person will very accurately set the instru- 
ment to the exact point where the two halves of the field of 
view appear of exactly the same color to him. 

After their neutral points had been found in this manner, 
these gentlemen very kindly offered to spend the time neces- 
sary to obtain curves for their retinal persistence. 

Mr. W. C. W. is a marked case of inherited blindness to 
red. His father, uncles and brothers are similarly affected. 
The red end of his spectrum ends at about ‘688 A, and his neu- 
tral point is at +510 2 His eyes are otherwise normal. 

Mr. H.S. has inherited green-blindness from his maternal 
relatives. Daltonism is so very rare among women that his 
case was studied with great interest. He is making a specialty 

*How do the color-blind see the different colors? Proc. Roy. Soc. Lond., 
xxxi (1880), p. 302. 

3°95 per cent among males. ‘Color Blindness: its dangers and detection.” 


(Boston: 1879.) 
¢ Zur Kentniss dichromatischer Farbensysteme. Wied. Ann, xxii (1884), p. 567. 


202 kL. S. Ferry—Persistence of Vision. 


of botany and finds no great inconvenience in any of his 
studies except chemistry. This subject he was obliged to dis- 
continue as he could not distinguish the characteristic colors 
of the reactions. His neutral point was sharply located at 
‘516 2. This gentleman wore glasses for near-sightedness. 


Duration of }mp |ression 


430 450 470 490 5/0 530 550 570 590 €10 .€30 €t50 670 €90 


Duration of Impression for different colors of red-blind Hye. 


The other observers were not aware of any similar cases in 
their families. The neutral point of Mr. G. A. W. was located 
at -b17 A> Mr. W. M. at 5165 2; Mas MeO Wesaty collsine 
Mr. H. C. H. at ‘5162. They are all green-blind and their 
eyes appear to be otherwise perfect with the exception of 
Mr. W. M., who is near-sighted. Their values of duration of 
impression are given in the annexed table. 

The values of Mr. W. C. W. are platted in the full curve 
fig. 3; the broken curve being the curve of the normal eye 
for the same brightness of spectrum. The values obtained by 
Messrs. W. M., H. C. H., and L. M. W. are platted in the 


ES. Ferry— Persistence of Vision. 203 


curves in fig. 4. The normal curves are drawn in as before to 
show the relation between the normal and color-blind eyes for 
persistence of vision. 


TABLE VI. 
Duration of Retinal Impression for Dichroic Eyes, 


({TkLe numbers at the head of each column indicate the brightness of the spectrum.) 


Duration of Impression in Seconds. 


Red Blind. Green Blind. 
Wave- | | | | 
length. Mr. W.C.W. Mr. H.S. | Mr.G.A.W.) Mr. W.M. | Mr. H. C. H.| Mr. L. M. W. 
re 7 ei Since | 4, Da pe | 4. sais) 
| | | 
CCN Fee erg ee eee age 03570 Milne "0351 
“480 0294 OS dit | 0278 0333 | °0294 0250 
510! | -0227 iene 2204 ] Oa | 0263 0217 0192 
“525° | Aes 0208 | °0200 "0238 0208 0185 
540°) 0172 | 0200 | *0185 0222 0200 “0172 
RR, || SONG “0175 0179 °0208 “0193 *0156 
-570 | ‘0156 0161 “0161 "0192 | °0166 "0143 
589 | -0152 0143 OE? 0159 | 0151 °0125 
“615 0179 0154 °0156 “0175 es OuGH 0143 
(RS He Vis 0175 [ONGT) 1gn | ON 2e leon: Oi2 0156 
“684 ee 0210 | 0227 "0238 ho al “0179 
i | 


These curves show that light impressions of red last much 
longer on the retina of red-blind persons than on the normal, 
yellow somewhat longer than normal and the other colors about 
the same as normal. With green-blind persons, however, green 
impressions persist much longer than normal, red a little less 
than normal and the other colors the same as normal. 

An explanation of the difference between the duration 
curves of dichroic and normal eyes was found in the difference 
in the sensitiveness for different colors of the dichroic from the 
normal eye. Messrs. Macé and Nicati* from the examina- 
tion of a number of dichroic eyes obtained luminosity values 
which indicate, first, that red-blind people perceive red weakly, 
yellow nearly normal, green better than normal; second, that 
the green blind have better perception than normal for red, 
green feeble, yellow and blue normal. A later determination 
by Abney and Festing+ confirmed their conclusions. In this 
experiment luminosity values were also obtained from Mr. W. 
C. W. which agree with the two determinations just cited. 
This shows that if account be taken of the difference between 
the sensitiveness of the normal and the dichroic eye for different 


* De la distribution de la lumiére dans le spectre solaire (spectre des Daltoniens). 
Comptes Rendus, xci, p. 1078. 
+ Colour Photometry. Trans. Roy. Soc. Lond., 1888, p. 547. 


204 ELS. Ferry— Persistence of Vision. 


regions of the spectrum, that the curves of retinal persistence 
of the dichroic and the normal eye will be of the same form. 

This appears to make the evidence conclusive that color is at 
most a slight factor in retinal persistence, and that luminosity 
is the all-important function. 


ef Impression. 


Duration 


Duration of Impression of Green-blind Eye. 


The law previously derived connecting duration of impres- 
sion and luminosity of lights of the same color can now be 
made general and independent of color. This approximate 
empirical law can now be expressed in the concise form—dwura- 
tion of retinal impression ts inversely proportional to the 
logarithm of the luminosity, or in the form of the equation 

a 
k- log t- 


It is interesting to note the similarity of this with Fechner’s 
law* connecting the intensity of stimulus and the sensation 


Dye 


* Revision der Hauptpunkte der Psychophysik (Leipsig), p. 184. : 


ES. Ferry—Persistence of Vision. 205 


produced. Fechner’s law was also empirically deduced and 
has since been confirmed, for mean values, by Dalbout’s 
memoir to the Belgian Academy. It can be expressed in the 
form 
Si Wlogenc 
_ where s denotes intensity of sensation and « intensity of stim- 
ulus. In this particular case the stimulus is luminosity, hence 
we have 
Il 


LS 


a 


1D) = 


which means simply that retinal persistence varies inversely as 
the intensity of the sensation producing it. This seems to agree 
with ordinary experience and thus to confirm the validity of 
the law connecting retinal persistence and luminosity. 


Liffect of Age upon Retinal Persistence. 


It was thought that possibly as a person advanced in years, 
the retina might become selective in its sensitiveness for differ- 
ent colors and that therefore the curve of duration of retinal 
impression might be different from that of a younger person. 
Two professors in the University kindly permitted their eyes 
to be tested for retinal persistence and the values obtained are 
given in the annexed table. 


Taste VII. 
Waye-length. Duration of retinal impression in seconds. 
a Prof. S. G. W. Prof. EH. L. N. 
435 "0417 "0417 
*480 03833 "0357 
“510 ‘0217 {O24 
“540 70179 "0185 
570 "0156 ‘0161 
589 “0147 °0155 
615 "0156 ‘0166 
"645 °0185 S092 
"684 70227 0.2:2i7 


These values platted in fig. 5 seem to indicate that for both 
Dr. Nichols and Prof. Wilhams the more refrangible part of 
the spectrum is proportionately less luminous than to the eyes 
assumed to be normal. But the violet end of the spectrum is 
so feeble that observations in it are very difficult, and cer- 
tainty cannot be obtained without more extended observa- 
tions. If anything can be deduced from so few observations, 
these curves show to a high degree of probability that age in- 
creases retinal persistence to a considerable amount and that 


206 LF. S. Herry—Persistence of Vision. 


the increase is nearly uniform for all wave-lengths. This fact 
would be naturally expected, for it is well known that age de- 
creases retinal sensitiveness ; and as the sensitiveness decreases 
the action of the retina would be less quick either to receive 
an impression or to dismiss one. 


5 


: 7 
034 \ pot — 
\ 
Wea ma | 
osaf__ == 
cle 
030 — = L eer 
\ 
028 Mal —— ——— al td <== et 
\ 1 
\ \\ | 
026 \ 
Souigless ele otiatdel licen ie pe 
024 ‘y Wp 
| { 
\ aie wales 
\ \ Ba beara 
One| Le IN { = esias 
a \ | | i 
4 NN | 
020 2 aN, | [een [ 1g 
= Nga ec alii 
iS \ \ is H | fy Ya 
ee ae 
= i .! | | / | 
a \ IN Y) | 
v 016 = i \ S iS ae a | =| 
3 Saal i ie ayer ; 
PAL oN Seat S| 
jee Feet NY Ma eas et Near ee ce ai ! 
| See ware | | 
Wave Lenjgth. ising | | 
d12 L L 


430 450 470 490 5I0 530 350 570 590 6/0 630 650 670 690 


Summary of Results. 


I. The duration of retinal impression is very different for 
different regions in the spectrum, being at a minimum value at 
the region of maximum luminosity and gradually increasing to 
maximum values at the ends of the spectrum. 

II. If the luminosity of any region in the spectrum be so 
changed that the values vary in geometrical ratio, the corre- 
sponding values of duration of impression will approximately 
vary in arithmetical ratio for regions of ordinary brightness. 

III. Color has, at most, very slight influence upon retinal 
persistence. Luminosity,—including the brightness of the light 
and the retinal sensitiveness—is the all-important factor. 


S. E. Bishop—Kilauea in April, 1892. 207 


IV. For ordinary values the following empirical law is ap- 
proximately true—Letinal persistence varies inversely as the 
logarithm of the luminosity. 

V. The values of retinal persistence in dichroic eyes is very 
different than in normal eyes. For instance, light impressions 
of red last much longer on the retina of red-blind persons than 
on the normal, yellow somewhat longer than normal and the 
other colors about the same as normal. With green-blind 
persons, green impressions persist much longer than normal, 
red a little less than normal and the other colors the same as 
normal. 

VI, The very marked departure from the normal values of 
retinal persistence in dichroic eyes for the region of their 
lacking color sensation, affords a precise and convenient method 
of determining color-blindness. 

VII. Within the range of these experiments, it seems prob- 
able to a high degree that age increases the duration of retinal 
impressions to a nearly equal amount in all regions of the 
spectrum. 

In conelusion I wish to express my obligation to Mr. E. 
Gordon Merritt for his very valuable assistance in taking ob- 
servations in these experiments. 

Physical Laboratory of Cornell University, June, 1892. 


Art. XX VIL—Ailauea in April, 1892; by Rev. SERENO E. 
BIsHop. 


[Communication to J. D. Dana, dated Honolulu, April, 30, 1892.] 


ON a visit, a little over a fortnight since to the volcano of 
Kilauea, the condition of Halemaumau crater was found to be 
greatly changed from that in 1887, as described in your 
‘Characteristics of Volcanoes,” and which I had the satisfac- 
tion of observing in your company. It also differs so greatly 
from what has been hitherto put upon record, that I venture 
to send you the particulars, with some illustrations for such use 
as you may choose. 

At the collapse of the crater on March 5, 1891, precisely 
five years after the previous collapse in 1886, a deep open pit 
was left as before. The great mound* had entirely disappeared 
into the voleanic depths. Thé lava speedily reappeared with- 
out apparent obstruction, and has since then risen to within 
about 300 feet of the upper rim of Halemaumau, where it 
formed a floor of remarkable smoothness. Perhaps two months 


*The mound referred to is the ‘‘debris-cone”” which occupied the interior of 
Halemaumau, the pit in the southwest part of Kilauea. 


208 S. L. Bishop—Kilauea in April, 1892. 


ago it began to subside, and when [I last saw it, it was 40 feet 
below the level of the floor, having sunk about ten feet during 
five days. The diameter of the molten lake is just about 900 
feet, and that of the floor around it averages 1500 feet. 

I, 


D ; D 
oy - rE 
' : ‘eB 
: eS B x B 


900° 


Vertical Section of Halemaumau, April 13, 1892. 


Ground-plan of Halemaumau in the southwest part of Kilauea. 


Fig. 1 is a ground plan of Halemauman, and 2, a section of 
it, as it existed April 138, 1892. In each, A is the Fire-lake of 
that date 900 feet in diameter; BB, the level floor of blackish 
lava around the lake, about 40 feet above the surface of the 
lake, and 1500 feet in diameter; CO, the talus-slope making 
the chief part of the sides of the pit; D, section of the outer 
rim of Halemaumau. In the ground-plan, fig. 2, the outer 
dotted line, is the outline of 1886, as given in Dodge’s map ; 
DDD, depressed areas of the pit of that date, filled up by over- 
flows of 1889, 1890, 40 feet above the former level ; H, section 
of former margin of the pit still visible above recent over- 
flows; F, former position of Dana Lake. 

The activity of the lake, relatively to its area, is somewhat 
less than that of Dana Lake as you witnessed it, although 


S. F. Bishop—HKilauea in April, 1892. 209 


actually several times as great, and exhibiting larger single 
areas of violent activity. It differs materially from Dana Lake 
in the distribution of its action. The general movement of 
the thin crust is steadily from the periphery toward the center, 
where there is the greatest action. Long seams (fiery cracks) 
open near the outer edge, and draw inward, crinkling up as 
they progress, until they become interlaced. An open area of 
perhaps two acres at the center is occupied by a strong current 
pouring westward, filled with fragments of crust and exhibit- 
ing sparkles of fire with a multitude of small jets and sprays. 
This current disappears under the crust that extends out from 
the west side. Near the eastern edge of this central area there 
is a powerful fountain which did not intermit its action a single 
minute during several visits from the 8th to the 13th. Its 
movement was pulsating; about every twenty seconds it 
welled up in a round billow varying in diameter from 30 to 50 
feet, and from 20 to 35 feet high. There was no explosive 
action, or spray, except what was caused by the falling back 
of the upheaved fluid. 

A similar but smaller fountain played nearer the bank at the 
south. This, however, at my last visit, had exchanged its action 
for a more violent but intermittent one. Occasionally, and 
once for twenty minutes continuously, an area of 150 x40 feet 
was occupied by a violently tossing mass of surges, from 15 to 
25 feet high, the entire summit of which was feathery with 
spray. A similar but smaller area was several times in like 
action northwest of the center. 

The great regurgitating and explosive fountains under the 
little cliffs, which made the chief displays in Dana Lake, were 
scarcely to be found here. A slight occasional action of that 
surt was noticed at two points at the northwest edge. 

The remarkable fact is here to be noted, that no vapor 
could be distinguished without careful scrutiny. From the 
Volcano House, a column of very faint blue haze could be 
observed ascending, having the diameter of the lake. In the 
night, this column of vapor, illuminated by the fires, was more 
discernible. But from the edge of the crater, close at hand, 
it could barely be distinguished, even by night. I spent many 
hours on different sides of the crater, once walking around it, 
but never even perceived any odor of fumes when at the edge, 
although at some distance from it and all over the floor of 
Kilauea many crevices were emitting sulphurous fumes. At 
the present time, the lava seems to have no contact with old 
rocks near the surface, while the ducts below are doubtless 
heavily glazed, like those we saw at the bottom of “ New 
Rake? mies, 

The top of Halemaumau crater has been found by aneroid 
measurement to be from 30 to 50 feet higher than in 1886. 


Am. Jour. Sci.—Tginp SerRIESs, VoL. XLIV, No. 261.—SEPTEMBER, 1892. 
14 


210 C. S. Prosser—Devonian System 


There is every appearance that extensive overflows have taken 
place over every part of the rim since you were there, and 
there can be no doubt of a great accumulation of material, 
The “ New Lake” and the intervening depression are totally 
obliterated. The high promontory west of “ New Lake” is 
lost beneath the flood. The great depression at the south is 
also filled, though not quite to the general level. The conical 
form of Halemaumau has become very distinet, and is strongly 
appreciated in the ascent to it on nearly every side. 

The volcano will soon be very accessible for tourists. The 
Hilo road is perfectly graded and rolled, and will probably be 
completed in a few months, when the drive to Kilauea will be 
one wholly of pleasure. ‘The new hotel is a superior one, 
with lodgings for 70 guests. Plans are in progress for im- 
proving the walk over the lava. The whole is now in the 
hands of an active and enterprising corporation. 


Art. XXVIII.—The Devonian System of Eastern Pennsyl- 
vania ; by CHARLES 8. PROSSER. 


[Published by permission of the Director of the U. S. Geological Survey. ] 


DurineG the summers of 1884 and 1890 personal field work 
in southeastern New York, taken in connection with an oppor- 
tunity to carefully study the Devonian exposures of this sec- 
tion and those of eastern Pennsylvania in the summer of 1891, 
is believed to have furnished important data toward the proper 
correlation of this system with the typical Devonian section of 
central New York. Numerous sections crossing this series of 
rocks, with quite a collection of fossils, have been made in the 
region between the Lehigh river in Pennsylvania and the 
northern part of Green county, New York. A single section 
across the Devonian terranes of this district will be briefly 
described in order to make this work available for use in the 
construction of the Appalachian geological maps and for the 
purposes of general correlation. The section along the line of 
the Delaware, Lackawanna & Western Railroad, crossing Mon- 
roe county, Pennsylvania, is considered a typical section and it 
has been selected for the subject of the present paper. It is 
no more than just to state that the geologic structure of this 
region, some of which is decidedly complicated, and the strati- 
graphic position of the formations have been worked out and 
mapped by Professors J. P. Lesley* and I. C. Whitet in an ad- 

* The Geology of Pennsylvania, vol. i, 1858, pp. 270-289. For a statement of 
Prof. Lesley’s work in eastern Pennsylvania, see 2d Geol. Sury. Penn., A, p. 102 


and zbid., G®, pp. xiv, xx foot-note. 
+ Ibid, G*, The Geology of Pike and Monroe counties, 1882 


(O91 


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of Hastern Pennsylvania. 211 


fl 


\\- Highest fossils 


~~ Henryville 
ate 596". 


---- Fossils 


-- High Bridge 


oie 550" 


\\ =-- “Spraguevt lle 


490° 


\+-- East Stroudsburg 
y)} 403° 


Hn: 
iv) 
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= 
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x 
-3 


mirable manner, the ac- 
curacy of which has been 
personally tested in many 
localities. . 

The base of the section 
is the Upper Helderberg 
limestone (Corniferous), 
which is well exposed in 
the Di & W. Rak: cut 
one mile south of the 
East Stroudsburg station. 
The railroad cut is 
through an anticlinal fold 
and near the center the 
Cauda-galli grit is ex- 
posed, the limestone at 
the northern end of the 
eut being overturned. 
The Marcellus shales suc- 
ceed the limestone, one 
exposure being in the 
railroad cut a short dis- 
tance south of the sta- 
tion, and another along 
MeMichaels creek, oppo- 
site Elizabeth street, 
Stroudsburg. Fossils are 
not generally common, 
but at the northeastern 
end of the small ridge 


north of Scott street, 
Stroudsburg, is a bluish- 
black shale in which they 
are quite abundant.* The 
following species have 
been identified from this 
outcrop. (U. 8S. Geol. 
Surv., No. 1475 B’). 


* This locality was men- 
tioned by Prof. White; see 2d 
Geol. Surv. Penn., G®, pp. 115, 
116. 


212 CO. 8S. Prosser— Devonian System 


1. Leiorhynchus limitarts (Wan.) Halll22: 22222 ~.b. 2 25ie 
oe Chonetes nincronata Wallies: . bs Sass ass (aa) 
3.. Letopteria levis Wall.) 5.22 baec ee er 
4ustyliola jissurella Hall i222 ss. S22 eee (c) 
d. Orthoceras subulatiwm, Halll (2) 222 22) ee er) 
6. Pierinopecten dignatus Wall... 2-352 eee 
Gs 2° Gontalites sp. 25. oak. ota ees eee (77) 


About half a mile north of Kast Stroudsburg, another anti- 
clinal fold brings to the surface the Corniferous limestone and 
then there are no more noticeable exposures of rocks along the 
railroad until a point is reached a short distance north of 
Gravel Place. At this locality, about two and one-half miles 
from Stroudsburg, are exposures of rather coarse arenaceous 
shales on the northeast side of the railroad. The fossils are 
quite abundant, especially V2tulina pustulosa Hall. ‘he fol- 
lowing species were found at this place (No. 1475 C’ and C’). 


LeVaculina: pusiulosa, Tallies ee see esau (aa) 50 specimens. 
2. Ambocelia umbonata ae \ all. 2-22 eae (c 
3. hacops.rana (Green) Hall e255 5s aoe 3 
A, Spiriferammeronata(Con.) Bill 223222 See eee eee (7) 
5. Chometes: dejlecia Halls: (a2 ei 0k. See (*) 
6. Spinefera quanulijerd, Lalas. i. aes 22 ees epee (77) 
i” Modiomorpha subulta (Con. \Hall= = 32592 See (a) 
8. Modiomorpha concentrica (Con.) Hall (?)-.-----.-.---- (77) 
9. Eterinea flabellata, (Con.) stall 29 9S eae ee eee (77 
lO. -Palwoneilo constricta (Con) alll is sae See eee 2 
1 Ldiorhynehus nvulcvcosta) Welallieys se ee ee (r7) 
12 Pleur ot omit spe Gans Os. NS tos oe eee een (car) 
IS. Crmmoide neal yee ese Ss Sale oA a eee eee (77) 


It will be noticed that the above list is a typical Hamilton 
fauna and these arenaceous shales and thin sandstones make 
an outcrop nearly one mile in width. 

Near the top of the above zone is an arenaceous, slightly 
calcareous shale which in places, especially where not weath- 
ered, forms a massive stratum of very compact rock. There is 
a good exposure of this zone’ by the side of the Stroudsburg 
and Spragueville highway, on the western side of Brodhead 
ereek about one and one-half miles below Spragueville and a 
short distance south of Mr. E. Bonynge’s house. t Fossils are 
very abundant at this exposure, especially corals and erimoid 
stems : ; but there are also numerous specimens of brachiopods. 

Fauna of No. 1475 O*. 


* The relative abundance of the species is indicated as follows: 

aa = very abundant, a = abundant, cc = very common, c = common, 7 = rare, 
rr = very rare. 

+ This locality is described by Prof. White in G®, pp. 109, 271 under the head- 
ing of the * ‘Tully Limestone horizon.” 


of Eastern Pennsylvania. 213 


Tes! ESV NUE CR COUP OUasal UI U es ie PS ce leek un I la («) 
Be SPORE JenvOreaed a((C.is)) leat lets ptyn ees yas ARREST (a) 
SeSpiLefena nuicronatc (Cont)s illyanes. See ee spears = eee (c) 
EEO TOUS WV AClrn Cuace rive ned alll ates ME Meta ate iets 92) a (c) 
Bs IN OOMADS DOR CONGO ONG [SNE SSeS pie oe 5 = Sal ae yee (c) 
GarAthuresi spun enoudess(Maton) Halll: 223) Saket ss see ese (e) 
lc, LEM CTEOTOS TEHOO( EnKeemn) Na Nile a eee ss nee (¢) 
Cem COuprecanaenuamicaenta. (Con:) tds So foes ee eae (c) 
Oe Ali pG Genacnnr os (biG) WORN seater cee tS ee M as 2G) 
QOL ERO UMD OU ONO USCS 1 ENS Se i eee mee ay io) 
iE uopedolentusccarimactus. (Cow:)e Wall sss 2 2 ee Wee (7) 
12. Chonetes coronata (Con.) Hall__--.--- yn ele Nadie ie a eee (173) 
13. Strophodonta be ee (Cron) Ae lana seater ae a seat (a7) 
14. Leiorhynchus multicosta Hall (?) .--....----.--------(r7) 
15. Actinopteria decussuta Hall (?).-----------. pentane (2) 
16. Mytelurca (Plithomytilus) oviformis (Con. ) Fall mine (v7) 
MGPeRC ONO CARGURUS Nee ene Ne eet oye js! ee RL eh ea Tee LEN (ae7D) 
SMILEY CORASES Ny iste Lt Be ee SEs anaes ats SOE ah (77) 


Corals and Bryozoa. 


This horizon is especially important since Professor White 
considered it to be at the summit of the Hamilton stage 
and to represent the Tully limestone of New York. After 
describing the locality from which the above species were 
collected, the Professor stated “ There can be little doubt that 
this stratum represents the Zudlly limestone horizon of the 
New York Reports, and it thus becomes a valuable guide in 
correlating and classifying the rocks of the district.’+ How- 
ever, when this zone is studied carefully it will be noticed that 
it is usually a caleareous shale or sandstone, instead of a mas- 
sive limestone and does not lithologically resemble the Tully 
limestone of central New York. But, far more important 
than the lithologic character of the zone, is the fact that the 
fauna therein contained is composed of Hamilton species, 
while those which are especially characteristic of the Tuily 
limestone are absent.t This zone appears to,the writer to 
correspond with the calcareous layers that occur in the midst 
of the regular Hamilton shales of central New Tens rather 
than with the Tully limestone. 

While considering the correlation of this zone it is impor- 


* Snirifer fimbriatus Morton was proposed in 1836, this Jour, vol. xxix, p. 150, 
pl. Ll, fig. 1; while Conrad’s DPelthyris fimbriatus was named in 1842, Jour. Acad. 
Nat. Sci., Philadelphia, vol viii. p. 263. S. A. Miller in 1883, 2d ed. Am. Pal. 
Foss. named Conrad’s species Spirifera Conradana ; but in this paper the name 
by which the New York species is generally known has been retained. 

taGempr 19! 

{ For a list of the New York Tully fauna with a discussion of the species 
having a diagnostic value. see a paper by Prof. HI. S. Williams on ‘* The Cuboides 
zone and its fauna; a discussion of methods of correlation,’ Bull. Geol. Soe. 
Am., vol. i, pp. 490-494. 


214 C. 8. Prosser 


Devonian System 


tant to recall the known limit of the eastern extension of the 
Tully limestone of central New York, which formation was 
found by Vanuxem in Chenango county “ at the northwestern 
part of Smyrna, on the road to DeRuyter village, where the 
road crosses the west branch of the Chenango [river].”* In 
the summer of 1886 the writer studied this region, and near 
Upperville in Smyrna township reported limestone layers 
separated by calcareous shales, twenty-five feet in thickness.t+ 
Farther east in the Unadilla valley no representative of the 
zone was found. 

One fourth mile farther north than the outcrop of the eal- 
careous, coral zone, the highway crosses Brodhead creek and 
under the bridge and along the banks of the stream are 
exposures of rather finely arenaceous, bluish shales which are 
moderately fossiliferous. This zone is easily traced in the 
field on account of its being composed of thin, dark-colored 
shales which succeed the coarse arenaceous shales of the 
middle and lower Hamilton. One of the best localities for 
collecting fossils in this zone is in the gorge of the Sawkill 
creek, above Milford, Pike county, and the fauna of that 
station will be given for this horizon. (See fauna of No. 14767°.) 

The outcrop from which this fauna was obtained is one 
of the typical exposures of this zone, which was referred 
by Professor White to the Genesee shale. The fossils came 
from the upper part of the zone as exposed in the gorge of 
the Sawkill, which “rapidly excavates a long narrow caflon 
out of the Genesee shale.”+ While under the description of 
the geological formations, Professor White says that “the top 
of the /Zamilton is marked off everywhere in this district by 
the appearance of a dark sandy fossil slate or shale, which 
seems to be identical with the Genesee black slate of the New 
York Reports.”§ 

A geologist familiar with the Genesee shale of central and 
western New York will find some difficulty in correlating 
this zone with the New York Genesee. These shales have 


* Geol. New York, Pt. III, 1842, p. 292. Also, see p. 164. 

+ Proce. Am. Assoc. Ady. Sci., vol. xxxvi, 1887, p. 210. 

an (Ere joy NGS): 

$ Ibid.. p. 107. Professor Lesley called these shales Genesee in the explana- 
tion of the geological structure of Monroe Co., Report X, 1885. p. Ixxx. 

Mr. Arthur Winslow in his work along the Lehigh river named the continua- 
tion of these shales Genesee, and mentioned them particularly at Weissport (Ann 
Rept. Geol. Surv. Penn., 1886. Pt. IV, pp. 1365, 1367, 1371). Also, see Winslow’s 
map and section from exposures along the Lehigh river, sheet No. 3. In the 
continuation of the Lehigh section down the river by Mr. Frank A. Hill, similar 
shales are called Genesee (Jbid. pp. 1373. 1374). A considerable collection of 
fossils was made from near the Weissport station of the Central Railroad of New 
Jersey, and from the R. R. cut above Bowmans; the Jithologic character of the 
shale aud the fauna is about the same as in the exposures of the same zone 
farther northeast in Monroe and Pike counties. 


od 


of Lastern Pennsylvania. 215 
Fauna oF No. 1476 F?; WITH TABLE OF GEOLOGIC RANGE. 
| | Geologic Stage.* 
| Ean 
el 2a ee) ie 
& List of Species. SS a a 
me - ao g oO n 4 ap 
= Wale yee ete SEP an gel) 
eth ESN os ra BE 0) Gos 
re By ae ye eee a Se 
= = aS) ay ea an be 
Z| a\6@BOD22 E0026 
1|Nucula corbuliformis Hall ------------ Ce Rie eve a en eee ne NL cee ne eater 
ALellinopsis.subemangimata (Cons) Halls |;a@)- 2225 222k 2 
3 Paleoneilo constricta (Con.) Hall _------ Mra ate ici ines We caer Can COLES. ee 
4) Nuculites triqueter Con.___._--_-------- Culpean ae Searing aii lle oan 
DeediomonpianmyLuovcess (Com) lla era ich yal Sey ec xa) 1 pea eg: ee 
6 Phacops rana (Green) Hall__-_--.----- COPTER SL LORD OSIIXe SC en Mae RE ti BLO 
7, Chonetes mucronata Hall __..-._-_---- CO AERTS EME aexeieh Oe it alk el DR eels 
SWELU OLULIVCSROUCUESE hl allem pte tae es eer CRINGE Sy Sea le Naat ee as Ce pee ae 
SE CUMOLO NO GUONPLUT Sie eliell We payee CR ketenes! Sa ARES Ci Mk eg Rae ee 
HOM orcnititas Olillonmyetins Coin.) 5 be SL IGP i oe ay a Be ea es a 4 fe 
11 Spirifera fimbriata (Con.) Bill....------ AAO Ge AN RIND Xa Mame Bl cA CER nS Py RO Sen 
WARE) GHG Jala See Ceo ak ee Eee (RAN ee Le/ aye PNA Eo ie sald eid ee Hee 
MS IBECHORGTUCTS Galella = = amen ire eee FUP ele ston gen eat eal: Plate ieee pe a tee 
14! Leda rostellata (Con.) Hall__--__------ TEIN ae pai ETA Roe oe Cees 
LaiOnthonota canmata Cone 2222 a= 52.2 THICMNgh Seek SiN a NEA So op 20 Og) rater i tan 
16 Prothyris lanceolata Hall __..___.___-- AD Es Het LU PLEO U ty gh a ges POSER Sg Loge 
17 Rholadella radiata (Con.) Hall_____--. Tl eli gk eae TSA ately Se MUR Se (eum 
MSiiGoncopnonancanuatan (Ooms) a cle?) iegs =e arta) ee ame a eel coe Te era SY Na) aah 
19 Modiella pygmea (Con.) Hall___.__---- Crp ee es Ota UB EELS aN he ue og ie ec al 
20) Orthonota (2?) parvula Hall__..__-_---. EIN esa a ay at EOP RL 3 MINN pie 
21 Athyris spiriferoides (Haton) Hall------ rr EN AME Ui ene XM EEE NL nate Pas 
22 Tropidoleptus carinatus (Con.) Hall__--- eT tee IMME SN st AVE LAN poly ME Ae 
23 Ambocelia umbonata (Con.) Hall __--_- TRA eAy oe Tien GIT Sabi ovale Mio ctvens Mite Geeta 
24) Coleolus tenutcinctwm Hall ._----.--_-- OPT a eee ot Ay ead de ohne Cogan Matic MSE crac V8 
25 Loxonema delphicola Hall (?)..-.------ BIG eID aN SSE eRe cn ae haa Sao 
ZorBellenophon leda- tially sae 52 he anys oe ARTES Wang Cre 8 A ah ee pyc ty Hees ye = 
27 Dalmanites (Crypheus) Boothi (Green) 
Hallpossibly the vars caliieles Green nie 25 88 xx XxX Se ee ee 
28) Orthoceras sp. fragments_-_____-..___ WE eta i ech MORE Res Bly Age ifs aug Pseped det ATS 
29 Spirifera granulifera Hall (?)_--.------ TAN clap eg A SN EADAU CBS cD CEA gh oe 
30\Grammysia liratu Hall?) -..____--_- papal es DURE AAS isan. 5 nore GAA eg 
31 Cyclonema hamiltonie Hall (?) _.-._-- GL ee SIT ET Ch ECS SOG WS Naa So a Se 
32 Bellerophon brevilineatus Con. (?) ------ IGOR ne ea ig eee RRP Pa OK Oe dors Ae ee ge 
* The data used in showing the geologic range of the species in the above list 


are derived principaliy from the various works of Professors Hall, H. 8. Willams, 
and Clarke, and the distribution is confined mainly to New York. ‘The reported 
occurrence of certain species farther south along the line of the Appalachians is 
intentionally left out of consideration, until further investigation shall enable us 
to compare their stratigraphic position and faunas more carefully with the New 
York series. Consequently the range of each species is based upon references 
concerning the reliability of which there is believed to be no question, or upon 
This is a principle that is fre- 
quently ignored in the preparation of large tables of distribution and range of 


data that are personally known to be accurate 


species. 


216 C. S. Prosser—Devonian System 


very little lithologic resemblance to the Genesee and the list 
of fossils given above shows that the fauna is not that of the 
Genesee, but rather one of the Upper Hamilton stage. Only 
one species of the list identified trom the upper shale of the 
Sawkill cation has been reported from the Genesee shale of 
New York, viz: Ambocalia umbonata (Con.) Hall.* 

In central New York the Genesee shale does not extend 
much farther east than the Tully limestone. Near Smyrna 
the writer found black, argillaceous shales some twenty feet 
in thicknesst and Vanuxem reported it farther east at North 
New Berlin,{ now New Berlin. In 1883 the exposures along 
the valley of the Unadilla river to New Berlin and then 
across the hills to Oneonta were carefully studied; but no 
evidence was found of the Genesee black shale or its fauna. 

The rather fissile Genesee (?) shales are succeeded by coarser, 
arenaceous shales alternating with sandstones of moderate 
thickness. The sandstones are slightly greenish-gray in color, 
quite micaceous and in lithologic appearance decidedly dif- 
ferent from the darker and more argillaceous shales below. 
Fossils are not common in this zone, but occasionally occur 
abundantly in thin layers. In the ledges along the hill-sides 
east of the highway, and by the side of the county road, just 
above the D. L. & W. R. R. crossing, about one-half mile 
south of Spragueville, are exposures of these arenaceous shales 
containing fossils. 

The fauna of No. 1475 0% "48 is as follows: 


I Palwonetiowplanaidiall =. (2052 2 ees eee (a) 
2 Nuculites oblongatus Cons 2 ea ee a] 
3. Palwoneilo emaryinata (Con.) Wall (?) var. Hine ea) 
5 IS PUUfend MCSASUNEGLOS sen allll aps 2 soaps Seeley gk (c) 
6.. (7?) Actinopteria ct. Boyds, Walla. 235402 a (C) 
te Nevculites\ ct. cunecjormis Cony as- 2-925 322 (ec) 
Su wErouvy nis lanceolata EXalll seen see geen Serer ee EY aN (7") 
9° Microdon (Cypricardella) greyaris Tall: 2355 222 ae (7) 
LOA Spuvfera imesacostalis Wall a2 2 eee eee (7) 
ld: .Onthonotal(?) parvulagMall(?)\ee2=ele ee (rr) 
12. Nucula corbudifor mis Hall 220-25. Geel a oe eee (rr) 
13. Tropidoleptus carinatus (Con.) Halls SSS ae eee (Gaal 
14; Homatonotus De Kays (Green) Emin 2222s eee (77) 
15; Leptodesma) Rogers? Hall (2) ia: Saas a aaa ee (GHP) 


The rocks from which the above fauna was obtained are a 
typical exposure of those which have been called Chemung by 


«Dr. J. M. Clarke in 1885 gave a list of fifty-five species that had been found 
in the Genesee shale of New York (Bull. U.S. Geol. Sury., No. 16, pp. 33, 69, 
70). To this fauna he has since added additional species; see, Am. Geol., vol. 
vili, August 1891, pp. 88-91. 

+ Proc. Am. Assoc. Ady. Sci., vol. xxxvi, p. 210. 

t{ Geol. New York, Pt. III, p. 292. 


of Eastern Pennsylvania. 217 


Professor I. C. White in eastern Pennsylvania. In describing 
this exposure Professor White said: “‘ Along the county road, 
about one-half mile below Spragueville, the Chemuny rocks 
are seen in cliffs of gray, fine-grained sandstone, quite fossz/- 
iferous ;”* and in his account of the geologic formations he 
further stated that “It was impossible to identify any of the 
beds between the base of the Catsk7ll and the top of the //am- 
alton with the Portage serves of other portions of Pennsyl- 
vania, either on lithological or paleeontological grounds, and 
hence I have applied the name Chemung to the entire interval, 
preferring to regard the Portage serves as absent from this 
district.”+ Several reasons are given for this correlation, that 
of first importance being ‘‘The occurrence of characteristic 
Chemung fossils throughout the entire interval.” Later, in 
describing the geology of the Susquehanna river region, Pro- 
fessor White stated that probably the beds in the lower part 
of the Chemung “are the equivalents of the Portage beds in 
New York ;’§ and in a letter dated February 22, 1892, empha- 
sizes the fact that he wishes the above statement to ‘apply to 
Monroe and Pike counties, and that the lower part of the ter- 
rane called Chemung in those counties corresponds to the 
Portage of New York. 

The fauna of this formation is not characteristic of the Ge. 
mung stage of southern central and western New York, or 
even of the highest fossiliferous pre Carboniferous rocks of 
southern Pennsylvania and western Maryland. On the con- 
trary it is a modified Hamilton fauna, similar to the faunas 
that occur in central and eastern New York in the Portage, 
especially after the Tully limestone and Genesee shale have 
disappeared. It hardly seems to be so late as the “Ithaca 
group,” but rather approaches the earlier modified stages of 
the Hamilton fauna, as possibly the Paracyclas lirata stage of 
Professor H. S. Williams, which is found well developed 
above the horizon of the Genesee shale at Oneonta and Nor- 
wich in central New York.| 

It is true that Spirifera disjuncta Sow. is reported from 
this formation ;4 and if the specimens were correctly identi- 

* G6 p. 272. 4 Ibid. p 104. + Ibid., p. 104. 

§ G7, 1883, p. 68; and see pp. 70 and 228 for similar statements. 

||See Prof. H. S. Williams, Proc. Am. Assoc. Adv. Sci.. vol. xxxiv. p. 225 and 
chart; and Prosser. dbid., vol. xxxvi, p. 210. This fauna characterized the 
Oneonta group of Conrad (not Vanuxem, who applied the same name to the over- 
lying gray and red sandstones and shales) which was composed of bluish shales 
with some sandstones and abundantly fossiliferous. The zone is well exposed in 
the quarry at the foot of the hill west of Oneonta, at Norwich in the quarry 
near the reservoir, and in the lower part of the high hill west of the village. 
For Conrad’s description of the ‘‘group” see Ann. Geol. Rept.. N. Y. 1841, pp. 
30, 31, 50, 53. 

| G5, p. 105. 


218 CO. 8. Prosser—Devonian System 


fied that would be almost conclusive proof of its Chemung 
age. But the writer has failed to find this species on the 
eastern side of the Pocono and Catskill mountains and is in- 
clined to think that Sprifera mesastrialis Hall, an allied 
species which is not uncommon, is the one reported for S. 
disjuncta, especially since the Cascade section of Susquehanna 
‘County, Penn., has been reported to contain “well-known 
Chemung shaly and flagey strata full of Spirifera disjuncta.”* 
Whea the section was examined in company with Professor 
H. 8. Williams it was found that the common species was S. 
mesastriaulis, which had evidently been mistaken for the S. 
disjuncta.t 

After considerable field work in southeastern New York and 
northeastern Pennsylvania, the conclusion is reached that the 
marine faunas terminated either shghtly in advance or soon 
after the appearance of the Chemung stage. In central and 
southern Pennsylvania and western Maryland, the conditions 
seem to have been more favorable and Spirifera disjuncta 
with other Chemung species occurs in rocks which are strati- 
graphically equivalent to the unfossiliferous beds farther 
toward the northeast. The geological collections of Johns 
Hopkins University contain a few specimens of Spirifera dis- 
juncta from near Cumberland, Maryland,t and Professors 
Claypole,$ White, Stevenson,4] Ashburner,** and Meektt+ 
have reported the species from a number of localities in Penn- 
sylvania and Virginia. 

These shales and sandstones of the Chemung series, which 
contain the highest fossil shells seen by Professor White, are 
succeeded by greenish-gray, thick-bedded sandstones—the 
Starucca sandstone of Prof. White—which at that time he 
considered the base of the Catskill t{ Later, Professor White 


2 (C0 {tek 

+See the remarks on the Cascade section by Prof. Williams, who states: 
‘When I examined the section I found no trace of several of the species cited, 
and only rare and imperfect specimens of Spirifera disjuncta and the last stage 
with Rhynchonella contracta; but all the mass of the fauna was Spirifera mes- 
astrialis and its legitimate associates, which is a jower fauna belonging to the 
more eastern part of this general area. The difference between the two Spiri- 
feras appears at first glance slight; but they are clearly distinct” (Proc. Am. 
Assoc. Ady. Scei.. vol. xxxiv. p. 231) 

tSee list of Chemung fossils from Maryland by Charles R. Keyes in Johns 
Hopkins Uniy. Circulars, vol. xi, December, 1891, p. 29; which specimens 
through the courtesy of Dr. W. B. Clark have been personally examined. 

§ E?, pp. 74, 77, 289, 291. 

| T2, pp. 98, 183, 194. 

| T?, pp. 76, 80, 133, 212, 214, 216, 225, 226; and Amer. Geol, vol. ix, pp. 10 
26 


a 


** B pp, 221, 225. 

+t Bull. Phil. Soc , Washington, vol. 11, Appendix, Art. vill, p. 34. 

ttG®. pp. 102. 103. See G*, 1881, pp. 59, 70, 73 and fig. 10 on p. 77 for the 
original description of this zone. 


of Eastern Pennsylvania. 219 


states “it seems probable that the 600’ of grayish green beds. 
at the top of the Chemung in Pike and Monroe which in G* 
were referred to the Catskill, under the name of Starucca 
beds, may be the equivalent of a portion of the Upper Chemung 
of this district [Susquehanna river region], and therefore 
erroneously referred to the Catskill in G*.”* In the letter 
mentioned above Professor White writes that 600’ of sand- 
stones which in G* were put in the Catskill should be added to 
the Chemung. Referring to the difficulty in separating the 
Chemung and Catskill the Professor says, “I think the only 
possible separation of Chemung and Catskill is that founded 
upon physical characteristics and in my opinion we should 
separate them at the horizon of the Jowest red beds, for these 
seem to come in at about the same general zone everywhere, 
and it is the only possible means of separation.” The Starucea 
sandstone is well exposed at Spragueville and in the first D. 
L. & W. R. R. cut north of the station. 

The second railroad cut, just north of the Brodhead creek 
railroad bridge, is in the New Milford red shale, which is now 
regarded by Professor White as forming the base of the Cats- 
kill. The red shales alternate with gray shales and sandstones 
as far as the “ High Bridge” over the West Branch of Brod- 
head creek where the Delaware river flags of White are reached.t 
At the southern end of the first railroad cut north of ‘ High 
Bridge,” in the lower part of the Delaware flags, a greenish- 
gay sandstone contains many impressions of Orthonota (2) 
parvula Hall,t a species that occurs in the upper Hamilton 
shales of Schoharie county, New York, as well as frequently 
in the argillaceous Hamilton shales of central and western New 
York. “There is also a breccia which contains fragments of 
brachiopod shells an@ fish bones. At the northern end of the 
cut are coarse, grayish. arenaceous shales in which fern-stipes 
occur, and one poorly preserved frond of Archwopteris minor 
Lx. (?) was found. 

The Delaware flags are succeeded by the Montrose red 
shale in the vicinity of Henryville,s and overlying these 
shales are the Honesdale sandstones. Near the transition from 

eG palo: +See G®, p. 100. 

¢ Dr. Charles E. Beecher has seen these specimens and agrees with the above 
identification. Dr. J. M Clarke has kindly compared some of the specimens with 
the types in the New York State Museum at Albany, and writes: ‘‘l see no 
reason why the shells in question should not be regarded as Orthonota (?) parvula 
in accordance with your identification; I have compared them with the types of 
O. (2) parvula and can find no distinctive characters.” 

§ From the railroad cut in the red shale, just south of Henryville station, 
Prof. White reported Archwopteris Jacksoni Dn. (G*, pp 103, #20). No speci- 
mens were found by the writer and the only fossils seen in the shale were 


fucoidal (?) fragments, which are frequertly seen in the red shales of the Che- 
mung and Catskill. 


220 C. S. Prosser—Devonian System, ete. 


White’s Montrose shale to the Honesdale sandstones, as ex- 
posed along the D. L. & W. R.R, occurs the highest fauna 
that has yet been found in Monroe and Pike counties, Above 
these shells no fossils were seen in the higher rocks, except 
undeterminable fragments of plants. The shells occur in 
some greenish, argillaceous shales, about one and one-half feet 
above red shales. at the northern end of the second railroad 
eut north of Henryville. Several good specimens of Spirifera 
mesastrialis Hall were found and one of Leda diversa Hall (?). 
Spiritera mesastrialis which is reported from the Hamilton of 
Schoharie county, New York,* is an abundant and well known 
species of the middle zone of the “Ithaca group” at Ithaca 
and is also found in the lower Chemung farther south in 
southern central New York+ and northern Pennsylvania,t 
while Leda diversa is a Hamilton species of eastern and cen- 
tral New York. The fossils seem to indicate that these shales 
are hardly younger than the lower Chemung and they might 
be still older, since the specimens of Spirifera a mesastrialis do 
not appear to be the variety which is found in the lower 
Chemung of southern New York; but on the contrary the 
form found in the older rocks of the Portage. The nearest 
correlation to the above is that of Professor Stevenson in his 
Vice-Presidential address before Section E of the American 
Association, in 1891, when he drew the line, separating the 
Catskill from the Chemung, between the Montrose sandstone 
above and the Montrose red shale below,§ which is at a part of 
the series not distant from the horizon in which the Spiriferas 
were collected above Henryville. 

Above this horizon coarse, gray sandstones and shales alter- 
nate with reddish shales. A thick mass of the red shale is 
well exposed in the railroad cut just west of Oakland. The 
cut below Mt. Pocono shows coarse, gray sandstone with frag- 
ments of fossil plants, thin, bluish, argillaceous shales, breccia 
and red shales, while in places the coarse gray sandstone con- 
tains quartz pebbles and is probably near the horizon of Pro- 
fesssor White’s Cherry Ridge conglomerate, about 500 feet 
below the top of the Catskill.| Tn veneral structure and 
lithologic appearance, these rocks are very similar to the typ- 
ical Catskill of the Catskill Mountains. 

On the summit of the Pocono plateau, about two and one- 
half miles north of Tobyhanna, is a massive conglomerate 
which is considered by Professor White as the Mt. Pleasant 
conglomerate at the base of the Pocono.4 

* Geol. Surv. N. Y., Paleontology. vol. iv, Pt. I, p. 417. 

+ Bull. U.S. Geol. Surv., No 3, pp. 17. 22) 24. 

¢ Proc. Am. Assoc. Adv. Science, vol. xxxiv, p. 231. 


§ Am. Geol.. vol. ix. p. 14. || G®, p. 78. foot note. 
“l).Ge spy SOw3 29! 


Hl. L. Wells—Cesium-Mercuric Ilalides. 921 


Conclusions.—As a result of this investigation no change is 
suggested for the Lower Devonian—the Cauda-galli grit and 
Upper Helderberg (Corniferous limestone). In the Middle 
Devonian the Marcellus is generally clearly defined, except in 
the upper part where it changes rather gradually from the 
argillaceous to the more arenaceous shales of the overlying 
Hamilton stage. The Hamilton as mapped and defined con- 
sists mostly of rather coarse arenaceous shales and thin sand- 
stones; but to these possibly should be added the calcareo- 
arenaceous zone (called Tully limestone) and the black, 
fossiliferous shales above (called Genesee). It is shown that 
the so-called Tully and Genesee stages do not agree with the 
New York formations in either lithologic or paleontologice 
characters. After the disappearance of the Tully limestone 
and Genesee black shale in central New York there is very 
little evidence of their reappearance in eastern New York. 
Therefore the correlation of the zones in Pennsylvania with 
these New York formations is considered as open to discus: 
sion. The Chemung series contains a modified Hamilton 
fauna similar to that in the lower Portage of central New 
York, after the disappearance of the Tully limestone and 
Genesee shale. Above this fauna are the Starucea sandstones, 
the New Milford red shales, the Delaware flags with Ortho- 
nota (?) parvula, and the Montrose shales in the upper part of 
which Sprrifera mesastrialis and Leda diversa (?) oceur. 
These fossils seem to indicate that up to this horizon this series 
of rocks may not be of later geologic age than the lower part 
of the Chemung stage. From the above statement the inabil- 
ity to indicate any sharp dividing line between the Catskill 
and Chemung series, or the Chemung and Portage stages, will 
be readily understood. 

Acknowledgment is due to Mr. Charles D. Walcott, Chief 
Paleontologist of the U.S. Geological Survey, and to Professors 
H. 8. Williams of Cornell University, I. C. White of West 
Virginia University, and Lester F. Ward of the U. 8. Geologi- 
eal Survey for suggestions and advice in this work. 

U.S. Geological Survey, May, 1892. 


Art. XXIX.—On the Cesium-Mercurie Halides; by H. 1. 
WELLS. 


It is to be expected that more complete series of double- 
halides can be made with cesium than with the.other alkali- 
metals, because it is the extreme member of the potassium 
group and the most electro-positive element known, and because 
cesium double-salts in general are less soluble than the corre- 
sponding compounds of the other alkali-metals. A thorough 


222 H. L. Wells—Cesium-Mercuric Halides. 


study of these compounds seems desirable since very little work 
has been done in this direction, and therefore the present in- 
vestigation of the czesium-mercuric chlorides, bromides and 
iodides has been undertaken. 

The following is a complete list of the previously described 
mercuric double. halides containing the alkali-metals and ammo- 
nium, as far as I have been able to find them : 


Na,HeCl, NH,HeCl, RbHe,Cl, 

Rb, HeCl, RbHeCl, KHg,! Cl, 2H, O 
Cs,HeCl, KHgBr, 

(NH), HeBr, NH. HeCl, oa allO) 

K,Hebr, KHe¢Cl,. H,O (NH,),Hg,Cl, . 4H,0 
Na, Hel KHegBr,. H,O 

K, Hel NaHeCl, . 13H,O 

(NH,),HgCl,.H,O0 NH,Hel,.14H,0 (NH,),He¢,Cl,, 
K,HeCl,. H,O KHel,.13H,0 


(NH). Hel, . 3H,0 


The greater number of these arrange themselves into two 
types with varying water of crystallization or withnone. There 
are two compounds of a third type, while the two remaining, 
more cowplicated salts, stand alone. The last two were de- 
scribed by Holmes.* 

An effort has been made to make the examination of the 
ceesium-mercuric salts very complete, but it is not safe to say that 
every possible compound has been prepared, for negative re- 
sults are uncertain. It will not be necessary to describe the 
unsuccessful experiments where mixtures or uncertain products 
were obtained. It is sufficient to say that other double-halides 
were repeatedly looked for in every direction, and every indi- 
cation of a new salt was followed up until a homogeneous 
product was obtained and analyzed. 

The following table gives a list of the salts that are to be 
described. One of them, Cs,HgCl,, has already been prepared 
by Godeftroy.t 


Ie Il. 
Cs,HeCl, Cs, HeCl, CsHegCl,t 
Cs, HeBr, Cs, HeBr, CsHgBr,t 
Cs, Hel, Cs, Hel, CsHel, 
Cs,HgCl,Br, Cs,HgCl, Br, CsHgClBr,f 
Cs,HgBr,I, Cs, HgBr,1] CsHgBrl, 

Cs,HgClI 
IV. Vie Wat 
CsHg,Cl, CsHg.Cl, 
CsHg, Br, 
Cs, Hg.I, CsHg,I, 
CsHg,ClBr, CsHg,CIBr,, 
* Chem. News, v, 351. + Berichte, viii, 9. 


¢ These compounds are dimorphous. 


Btn. = a5, 


H. L. Wells—Ccesium-Mercuric Halides. D238 


These salts confirm the composition of all the previously 
known alkaline-mereuric halides, as given in the preceding 
table, except the single compound (N EM lox Cl) 9 wit isvex- 
tremely probable, however, that the correct formula for this is 
NH,Hg.Cl,,, for Holmes obtained results slightly lower than 
his theory i in his ammonium determinations, and it would be 
scarcely possible to distinguish between the two formulas by 
analysis, as will be seen from the following numbers : 

Calculated for Calculated for 

(NH,)2He Cleo. NHsHgs5Cli. Differences. 
Mercy eres es.) 1057.0 71:00 0°30 
Ammonium: = 2 S222 1°41 1°27 0-14 


The differences between the amounts of mercury and cesium 
for the corresponding formulas are 0°80 and 0°85, so that it is 
evident that the czsium compound furnishes a far better 
means of determining the composition of the salts. 

The first type, Cs, HgH1,, isa new one. These compounds 
are interesting as exceptions to Remsen’s law concerning the 
composition of double-halides.* 

The salt Cs,Hg,I,, although standing alone among the czesium 
compounds, is a very well characterized body, and the com- 
pound (NH,),Hg¢,Cl,.4H,O, made by Holmes, belongs to the 
same type 

The results of the work on the ceesium-mercurie salts fulfill 
the expectations concerning the value of ceesiuia as a means of 
studying alkaline double-halides, for all the previously discov- 
ered types have been made with this metal, and one besides 
that had never been discovered. 


Preparation. 


The compounds were made by dissolving mercuric halides in 
hot solutions of czesium halides and cooling, or in some cases 
evaporating at ordinary temperatures, to crystallization. The 
relative amounts of the two halides and the dilution both have 
an important influence in determining the salt produced. In 
most cases dilution with water is equivalent to the addition of 
mercury, while concentration produces the same effect as the 
addition of a cesium halide. It has been noticed, where more 
than one salt is deposited from a solution by cooling, that the 
salts with more mercuric halides are formed first. This shows 
that cooling a solution may be equivalent to the addition of 
ceesium. 

There are only a few of the salts that can be recrystallized 
unchanged from water, most of them requiring the presence of 
an excess of cesium halide, or in two or three cases mercuric 


* Am. Chem. Jour., xi, 296; xiv, 85. 


224 HI. L. Wells—Cesium-Mercuric Halides. 


halide, for their formation. Crystallization from water ean 
therefore often be used for preparing one salt from another. 
All the compounds were made with solutions of the normal 
salts without the use of acids. Some of them have been made 
with aleoholie solutions, but this solvent has not been found to 


possess any advantages except for preparing CsHg,]I,. 


Analytical Methods. 


The salts were always carefully examined to be sure that they 
were not mixtures. Many mixed crops of crystals were ob- 
tained, but I am contident that the products analyzed were 
pure. The crystals for analysis were always quickly and thor- 
oughly freed from the mother-liquor by pressing repeatedly 
between smooth filter-papers, and, at the same time, they were 
crushed to remove included liquid. During this drying process 
the substances were erquose to the air as little as possible to 
aveid any evaporation of the adhering liquid before its removal. 
After the products had been dried as thoroughly as possible in 
this way, they were usually exposed to the air for an hour or 
two to remove the last traces of moisture, but this was not done 
in a few cases where I wished to be certain that no easily-lost 
water of crystallization was present. 

Portions of abont one gram of substance were usually t taken 
for analysis In no case was the analysis hampered from lack 
of material. The chlorides and looms were readily dis- 
solved in water, but it was necessary in analyzing the iodine 
compounds to dissolve them in water ¢ containing alcohol. Mer- 
cury was invariably determined as sulphide, the precipitate 
being collected, dried at 100° and weighed on an asbestos filter 
ina Gooch crucible. Czsium was usually determined in the 
filtrate from the mercuric sulphide and was always weighed as 
sulphate. In this operation the excess of sulphuric acid was 
removed by ignition in a current of air containing ammonia, as 
suggested by Kriss for potassium sulphate. In some cases 
where cesium alone was to be determined, the substance was 
weighed out directly into a platmum er ucible, s sulphuric acid 
was added, the excess of this and the mercury were removed 
by evaporation and heating and normal czesium sulphate was 
weighed. The halogens were invariably determined in separate 
portions and were weighed as silver salts. In the cases where 
two were present, they were determined by heating the mixed 
silver halides to constant weight in chlorine. ~ 


The Double-chlorides. 


These are all white in color and are permanent when ex- 
posed to the air. On reerystallizing from water all of them 
finally yield CsHgCl,. 


H. L. Wells—Cosium-Mercuric Halides. 225 


Cs,HgCl, is made by dissolving a comparatively small quan- 
tity of mercuric chloride in a nearly saturated cxesium chloride 
solution. It is deposited on cooling, but the best crystals are 
obtained by spontaneous evaporation. If too much of the 
mercuric compound is added or if too much water is present, 
other double salts or mixed products will be obtained. On the 
other hand, if too little mercuric chloride is present, czesium 
chloride crystallizes out. The hmits of the conditions under 
which it is formed are narrow, but by repeated trials, with 
slight variations suggested by previous results, a pure product 
is readily-obtained. It forms slender, radiating prisms which 
are easily distinguished from the compounds with which it is 
liable to be mixed. 

The following analysis was made of a sample which was 
rapidly dried on paper, but not air-dried. The small amount 
of water found was probably simply moisture. It was deter- 
mined by direct weighing in a calcium-chloride tube. 


Calculated for 


Found, Cs;HeCl;. 
(Cepia e2an gases ere yilealesy 51°38 
WET CIN: Wenn sireehe 24°84 25°76 
C@liorime ee wae TaD 22°86 
AV Vicar seen nents cor ara nk 1°69 0:00 

99°47 100:°00 


Us,HgCl, is produced, by cooling a hot solution, when a 
little more mercuric chloride or water is used than in the case 
of the last salt. The conditions for its formation are narrow. 
It forms large but usually very thin plates which are readily 
distinguished from the other double-chlorides. A sample was 
dried on paper for analysis. 


Calculated for 


Found. Cs.HgCl,. 
@zacsiuime: eee 44°06 43°75 
Mere uty. tas oe eee actsias 32°90 
@lonine: ele Oi 233315 
Wrateneae iioesee eo 0°52 0:00 
100°00 


CUsHgCl, is dimorphous, forming, according to circumstan- 
ces, cubic or orthorhombic crystals. The cubic form is pro- 
duced, under widely varying conditions by cooling dilute 
aqueous solutions, when cesium chloride is considerably in 
excess. The orthorhombic form is deposited when cesium 
chloride is not in great excess and by one or more recrystal- 


AM, Jour. Sci1.—TuHirD Series, VoL. XLIV, No. 261.—SEpTtEMBER, 1892. 
15 


226 H. L. Wells—Cesium-Mercurie [Halides. 


lizations from water of all the double chlorides. This form 
ean be recrystallized from water indefinitely. 

The compound is practically insoluble in absolute alcohol, 
but it dissolves in alcohol diluted with about one-third of its 
volume of water, and it is remarkable that the ewhie form is 
deposited from such a solution on cooling. 

The cubes often form peculiar averesates, apparently of a 
pyramidal shape. The orthor hombic ‘crystals. are very brilliant 
and highly modified, usually forming groups of spear-shaped 
individuals joined end to end. 


Three samples were analyzed; A, cubes simply dried on 


paper; B, cubes from alcohol ; C, orthorhombic lenystales alr- 
dry. 
Calculated for 
Found. ‘CsHeCls 
A B C 
Cesium... -_-- 30°29 30°26 29°92 (30-26% 
Mercury _---- 44°80 .__. 45°63 45°51 
Chionines=se = 28 AO Peete 4208 24°28 
Walters i fates srl eae) ed 0:00 
99:91 99°58 100°00 


Since the orthorhombic form of this compound is not de- 
composed by water its solubility could be determined. This 
was done by analyzing the mother-liquor from a third recrys- 
tallization at about 17°. Of this solution, 100 parts contained 
0-4255 parts of cesium, corresponding to 1:406 parts of 
CsHgCl,. 

Os Hg, Ct, was made by dissolving 24. of CsHgCl, and 16 g. 
of HgCl, (a little more than one molecule of the latter) in 
about 150 ¢.c of hot water and cooling. <A large crop of 
needles was obtained which were undoubtedly homogeneous. 


Analysis Calculated for 
gave. CsHe.Cl;. 
Cesium aoe eee Sse 18°72 
Me eur vis etete aiees ae 56°32 56°30 
Chiorineesss ee 24°68 24°98 
99°13 100°00 


The salt is not very readily decomposed by water, but by 
repeated recrystallization the orthorhombic form of CsHeCl, 
is obtained. 

CsHq,Cl,, was prepared by making a nearly saturated solu- 
tion of 12:5 g. of HgCsCl, and 38-5 eg. of HgCl, (about one 
molecule of CsCl to six of HgOl,) in boiling water and cool- 
ing. The compound was obtained in prisms, so well formed 


H. L. Wells—Cowsium-Mercuric Halides. Di 


that there was no doubt about their homogeneity. Two crops 
were analyzed. 


Calculated for 


Found: CsHg;Cli. 
@siwim’ Bee ee 8°68 8°51 8°73 
Mer cunyasaee eae Gora Ort aes 65°64 
Chlorine sa Dae Oe sae ais. 25.63 
99°24 100°00 


A single recrystallization of this salt from water gave a 
mixed crop of crystals and this, on repeating the operation, 
gave CsHg,C], still contaiming a little of the original com- 
pound. This last crop was analyzed. 

Calculated for 
Found. CsHg.Cls. 
Ceesiuime tas See se 5e5i 18°72 


The Double Bromides. 


All of these salts are white, or nearly so, except CsHgBr, 
which has a lemon-yellow color. This color is remarkable 
since CsBr and HgBr, are both pure white. 

All of the double bromides yield CsHg,Br, on recrystallizing 
them one or more times from water. It is to be noticed that 
this salt belongs to a different type from the double-chloride 
which is stable with water, but if alcohol is used for reerys- 
tallizing this bromide, the salt corresponding to the chloride 
just mentioned is deposited. 

Cs, Hg Br,.—The preparation of this salt is exactly analogous 
to that of the corresponding chloride, and it has the same 
appearance. 


‘Calculated for 


Found. Cs3HgBr;. 
Caesiumineaets oe ee 39°83 39°94 
Mieneuiy eee ee ei a 19°50 20.02 
BOM. te Aree re 39°60 40°04 

98°93 100:00 


Cs,Hg Br, is prepared similarly to the chloride, but the 
limits of the conditions under which it is formed are much 
wider. Like the chloride it usually forms very thin plates, 
but they can sometimes be produced of sufficient thickness for 
measurement. Three separate crops, made under considerably 
different conditions were analyzed. 


228 H. L. Wells—Cesium-Mercuric Halides. 


Calculated for 


= Found — Cs.He Bry. 
Czsiumee Gaeyeh | BELTS | AG) 33.84 
Mercury ----- 95°68 Qo W545 95°45 
Bromine .--- - 40-48 40°40 40°52 40.71 
100°:°00 99:94 99°66 100°00 


'sHqBr,.—This compound is dimorphous, but while one 
form is cubic, ike one of the chlorides, the other is mono- 
clinic and has no apparent relation to the orthorhombic 
chloride. Just as in the case of the chlorides, the cubic form 
is produced when an excess of the czsium halide is present, 
while the second form is deposited when this excess is not as 
great. Unlike the corresponding chloride, the second form of 
the bromide is decomposed by recrystallization from water, the 
salt CsHg,Br, being formed, but, as will be noticed beyond, 
the opposite transformation can be produced by recrystallizing 
the last mentioned salt from alechol. The limits of forma- 
tion of the cubic salt are wide, but it is difficult to produce 
the other form in a pure state, and it is possible that the mono- 
clinic crystals analyzed were mixed with a small quantity of 
the cubes. 


—--— Found —_ Calculated for 

Cubic. Monoclinic. CsHeBryg. 
(Opeqiuline sus be asc Zils 22°89 DRO 
Mencunygss 2 ye) (S469) 35°54 34.90 
Brominerss 2 se 41°70 41°63 41°89 

99°83 100°06 100:°00 


CsHg,Br,—The recrystallization of any of the other 
double-bromides from water produces this salt, and it can be 
recrystallized indefinitely without decomposition. It forms 
very small, thin plates which have a very faint tinge of yellow. 
By spontaneous evaporation of a mother-liquor from a recrys- 
tallization of this salt somewhat larger crystals were formed. 
Three separate crops were analyzed. 


Calculated for 


Found. CsHg2Br;. 
Cesium_._. 14°60 14:69 13:24 14:26 
Mercury =o 04227 reer) ls ae 42°87 
Bromine 425 eee phat 49.87 
99°86 100.00 


The mother-liquor frony a third recrystallization from water 
at about 16° was found to contain 0°1151 per cent of cesium, 
corresponding to solubility of 0-807 parts of CsHg,Br, in 100 


H. L. Wells—Ccesium-Mercuric Halides. 929 


parts of the solution. The salt dissolves rather sparingly in 
hot, strong alcohol and, on cooling this solution, the compound 
CsHeBr, Separates out. 


Calculated 
Found. for CsHgBrs. 
Gees iin aes ee ee 22°68 2302) 


The crystals thus obtained were not large enough to measure, 
but it was probable, from microscopic examination, that they 
were the monoclinic form of this compound. This is interest- 
ing from the fact that it is the cubic form of CsHgCl, which 
erystallizes from alcoholic solutions. 

No satisfactory crops of crystals were obtained from solu- 
tions made with CsHg,Cl, and HgBr, together. 


The Double Todides. 


These salts are all yellow, CsHg,I, and Cs,Hg,I, having a 
color nearly like that of normal potassium chromate, while the 
others become paler as the cesium chloride increases. All of 
them are decomposed by water, forming compounds containing 
more mercuric iodide than the original salt, or, at last, mercuric 
iodide itself. It is therefore possible to take any one of these 
double-salts, and, by recrystallizing from water and evaporating 
the resulting solutions, to prepare the complete series of five 
double-iodides, as well as the component simple iodides, with- 
out the use of any new material. It is noticeable that the 
iodides differ from the chlorides and bromides in not including 
a salt that can be recrystallized continually from water. This 
peculiarity is doubtless due to the comparative insolubility of 
mercuric iodide. In most cases, the analyses of the salts con- 
taining iodine show an excess of mercury and a deficiency of 
the halogen (or halogens). It is not known whether this was 
due to some impurity in the salts or to analytical errors. It is 
not considered probable that inaccuracies in the analyses could 
have caused so much variation from theory, for the methods 
used were the.same as for the chlorides and bromides, except 
that alcohol was used as a solvent, and, while halogens and 
mercury were always determined in separate portions, the sum- 
mations of the analyses were usually satisfactory. 

Cs,HgI,—This salt, like the corresponding chloride and 
bromide, requires for its preparation a very concentrated solu- 
tion of the cesium halide containing a relatively small amount 
of the mercuric compound. It crystallizes well and may be 
obtained, either by cooling or spontaneous evaporation. The 
crystals form peculiar, steep pyramids. 


230 H. L. Wells 


Cesium-Mercurice Halides. 


Calculated 
Found. for Cs,HeIs. 
Gresiam oo Se ee ee 33°02 32°33 
Mercury 22-4 sk ee eee 16°3: 16°21 
ho@dines sc) aces eae lee 50°42 51°46 
99°77 100°00 


Its specific gravity taken in benzol was found to be 4°605. 

When this salt is dissolved in a small quantity of hot water 
the compound Cs,HglI, crystallizes out on cooling, but with a 
larger quantity of water everything remains in solution. 

Cs, Hg/,.—This salt is produced under wide limits of condi- 
tions by cooling solutions of the component salts when cesium 
iodide is in excess. The monoclinic crystals vary in habit, 
forming long prisms, nearly square plates or intermediate 
forms. They are often obtained of very large size, sometimes 
extending completely across the bottom of the vessel contain- 
ing the solution and turning upwards at the ends besides. 


Calculated 

Found. for Cs.Hel,. 
(Cereb ES en on@ 27°39 Dio} II 
iMencunyie ss arses 21°57 D9 20°53 
odin e mera eene ees SA GiNol®) 52°16 
100°30 100°09 100°00 


Two determinations of the specific gravity, taken in benzol, 
gave the numbers 4°799 and 4°812. 

The salt is decomposed by water, giving, according to the 
quantity used, either one of the salts containing more mercuric 
iodide or mercuric iodide itself. It is not dissolved or decom- 
posed by alcohol. 

CsHgT,(. H,O ?).—This salt is formed only within very nar- 
row limits from solutions containing a little more mercuric 
iodide or water than those from which the preceding salt is 
obtained. These conditions are perhaps most easily reached 
by dissolving the last salt in a small amount of hot water and 
cooling. It often happens that the three salts Cs,Hg,I,, 
CsHglI, and Cs,HgI, are successively deposited as a solution 
cools, and it is consequently difficult to obtain the salt under 
consideration in a pure state, but this was accomplished after 
a great many trials with varying conditions. The compound 
forms very thin transparent plates which usually radiate from 
a point and are often of large size. By pressing on paper they 
rapidly become opaque. Whether this is caused by molecular 
re arrangement or loss of water of crystallization is not certain, 
for, on account of the extreme thinness of the crystals, it was 


HT. L. Wells—Cesium-Mercuric Halides. DSi 


impossible to decide whether a small amount of moisture or a 
molecule of very unstable water of crystallization was present. 
Two samples were analyzed. A was air-dried after pressing 
on paper; B was quickly dried on paper. 


Found. Calculated Found. Calculated 


IN for CsHgls. B. for CsHgI,.H.0. 
Cesium) 2222" 18:8) 18°63 18°25 WONG 
MWrereuisye2 242.929 28°01 28°74 27°33 
Hoghine: 2252 HL EGK0) 53°36 50°98 52°05 
VAY GH Wes Raich Se 0:00 Dae 2°45 


99°60 100-00 100°48 100-00 


Like all the other iodides, this salt is decomposed by water. 
Cs, /1q,/, is formed under widely different conditions. It is 
most convenient to prepare it by dissolving Cs,HgI, in the 
proper amount of hot water and cooling. It is also formed, 
in a finely divided condition, by treating the same salt with 
not too much cold water. The crystals vary considerably in 
habit, but they can be readily distinguished from the other 
iodides. A characteristic form is a triangular plate, but plates 
of different shape and more or less elongated prisms often oc- 
cur. The following analyses were made of separate crops. 
Sample C was made by treating Cs,HgI, with cold water. 


— —-Found.- ——. Calculated 
m——A. Tear B. Of . for CseHgsls. 


@-estume eases SSO a sents WA Ay kas Of 14°13 
Mercury .- +. BiG, ye ES s3583 31°88 
Vodine 2 4 eo nOnimeo 220 52:63) 52:96 53°99 

99°72 100°86 100°00 


Specific gravity, taken in benzol, 5-14. The salt dissolves 
in alcohol. It is decomposed by water with the separation of 
a part of the mercuric iodide. From the solution thus ob- 
tained, the salts containing less mercuric iodide can be pre- 
pared by evaporation. 

COs Hg,l,.—When a hot aqueous solution of caesium iodide is 
saturated with mercuric iodide, this compound is formed on 
cooling, but, under these conditions, the substance is usually 
mixed with HglI, and often with Cs,Hg,1,. When weak aleo- 
hol is used as a solvent, however, a pure product is obtained 
without difficulty. It forms slender yellow prisms which be- 
come red on standing in an aqueous mother-liquor. They are 
more permanent in the solution when it is alcoholic, but, on 
drying them by pressing on paper, they quickly assume the 


* By loss at 100°. 


232 H. L. Wells—Cosium-Mercuric Halides. 


red color of of mercuric iodide without losing their form. It 
is probable that the spontaneous decomposition results in the 
formation of Cs,Hg,I, and Hgl,. It was necessary to analyze 
the material which had become red. 


Calculated 

Found. for CsHguls. 
Coe shits prs te one melee duy 11°39 
Mier cuniy,. 32 ees ee eee 35°73 34°25 
Todin Ge se wea ey pee ee 52°93 54°36 
100°18 100°00 


The Mixed Double-halides. 


A great deal of labor has been devoted to a study of these 
compounds in order to find to what extent they could be pre- 
pared. The results show that ceesium chloride and mercuric 
bromide unite readily although there is a tendency towards an 
exchange of halogens and the formation of unmixed salts. It 
is also notewor thy that, while there is a double chloride as well 
as a double bromide which is not decomposed by recrystalliza- 
tion from water, all the chloro-bromides finally yield mercuric 
bromide when so treated. 

The number of bromo-iodides is less than that of the 
unmixed salts, for, when attempts are made to prepare com- 
pounds containing the larger amounts of mercuric iodide, 
there is an exchange of halogens and almost pure double 
iodides are produced. 

Only one compound of mercuric iodide with cesium chlo- 
ride could be prepared. This is Cs,HgCl,I,, and the type 
to which it belongs may probably be considered, on this 
account, the most stable one of the ceesium-mercurie halides. 

It is evident that the mixed salts are not as readily formed 
as the unmixed, and that the more dissimilar the two halogens 
are, the less tendency there is to form the mixed compounds.* 

In preparing these salts, containing two different halogens, 
the halogen of higher atomic weight was always added in 
combination with the mereur y. The methods of preparation 
are exactly analogous to those by which the unmixed salts are 
made, so that most of these details will be omitted in describ- 
ing them. 

The Chloro-bromides. - 


In form these all resemble the unmixed salts between which 
they are intermediate, and all of them are colorless except 
CsHgClBr,, which is pale yellow. 


* This point is discussed in connection with the ceesium trihalides. (Wells and 
Peutield, this Journal, III, xlii, pp. 31 and 32.) 


HT, L. Wells—Cesium-Mercurie Halides. 933 
Cs, Hg Cl, Br,.— 

Calculated for 

Found. Cs;Hg¢Cl, Bro. 
Cxesiumuketas eee 48:12 46:10 
MenG us a2 ae oe 25°80 23°11 
@hlornnes2ee= oso 16°24 12°30 
ROMIMe =e ee 11°82 18°49 
99 98 100:00 


The product was made with a very large excess of ceesiuin 
chloride, and it contained a considerable amount of the double 
chloride. The analysis corresponds nearly to the formula 
2Cs,H¢Cl,Br,+Cs,HgCl,. 

Us, MgCl, Br,—Two products, which were made under 
different conditions, were analyzed. 


Caleulated for 


Found. Cs. HeCl.Bre. 
(CRISiiNiins 225 Je hehe 40°34 38°86 38°16 
Meicuiyy see a 28579 28°58 28°69 
Chilouinetes see | LOLOA 10°48 10°19 
BROMINe hess ese 5. 17:43 22°07 22°96 
99°50 99°99 100 00 


One of these crops corresponds very closely to the formula, 
while the other, made in the presence of a greater excess of 
cesium chloride, contains a little Cs, HgCl.,. 

CsHgClBr,.—This has been obtained, like the chloride and 
bromide, in dimorphous forms. One of ‘these is cubic like the 
other salts, while the second form erystallizes like the chloride 
and not like the bromide. The color of both varieties is pale 


yellow. 
——- Found. 
Orthorhombie form. Calculated for 
Cubic form. Separate products. CsHgClBre. 
(CEssiinidips sae OO) 96:0 26142 26-011 PRON 
Mercury ee OMe 40°21 40°05 38:91 37°84 
Chlonnme 2252)'29:23 Tale 2 ihe 8°53 6°72 
Bromine _ 222 25°24 21635 2094) 26°65 30°27 
99°69 100°13 100°15 100°10 100°00 


These products evidently contain some of the chloride. 
The analyses of the first two samples of the orthorhombic salt 
correspond closely to the formula, 2CsHgClBr,+CsHgCl.. 

Csg,C1Br,.—Two separate products, made under different 


conditions, were analyzed. 


934 EAB: Wella Cesium Meneame Halides. 


Calculated for 


Found. CsHe.ClBry. 
Gesumies: eee 15°48 ORS} 14:97 
Mercury] =o ee 45°72 45°06 45°02 
Chloriner eee 55 Sail 3°99 
Brominess se 32°30 36°06 36°02 
99°25 100°06 100°00 


CsHg,C1Br,,.—This compound was prepared by recrystal- 
lizing the preceding salt from water. 
Calculated for 


Found. CsHg;ClBrjo. 
Cassius. cere eae 6°23 6:76 
Mercurie eee ein 50°80 
Chlonnevese sae 2°85 1°80 
Brominee eee ease 38°19 40°64 

100:04 100:00 


There is a chloride corresponding to this compound, but no 
bromide was obtained of this type. It forms elongated erys- 
tals much smaller than the chloride. The final product, when 
this salt is recrystallized from water, is mercuric bromide. 


The Bromo-iodides, 


Only three of these compounds have been prepared. When 
attempts were made to obtain compounds containing larger 
amounts of mercuric iodide, there was an interchange of halo- 
gens and nearly pure double iodides were formed. Two such 
products were analyzed. 


Calculated for Calculated for 
Found. CsoHesIs. Found. CsHgols. 

(CES Ae ee 14°69 14°13 11°62 11°39 
Mercury ees 25 33°72 31°88 36°09 34°25 
Biomineweare. = 2°19 0:00 2°43 0-00 
Todine= ss 2222 49°58 53°99 49°45 54°36 
100°18 100°00 99°59 100:00 

Cs, Hg Br,f,,—This salt resembles the iodide, not the bro- 

mide, in form. Its color is a pale yellow, intermediate 


between the brighter iodide and the colorless bromide. 
Calculated for 


Found. Cs3HgBrglo. 
Gesiumanes eee 37) 36°50 
Mencunygeeeeee oes 19°39 18°30 
Bronmi@ere se see NS 21:96 
Todines 25.2" oa 18°24 22°94 


100°02 100-00 


H.. L. Wells—Cesium-Mercuric Halides. 935 


Cs, Hg Br I,.—This compound has a very faint tinge of 
yellow. It is apparently dimorphous, although no other salt 
of this type has been made in more than one form. It occurs 
in very thin plates, like the chloride, bromide and _ chloro- 
bromide, and in stout monoclinic crystals like the iodide. The 
limits of the conditions under which the plates are made are 
very narrow, and it is difficult to obtain them free from the 
dimorphous crystals. As the solution cools, however, the 
plates are deposited first, and, with the proper dilution, it is 
possible to remove them and get the mother-liquor pressed out 
with paper before the other crystals begin to form. There is 
no difficulty in preparing the other modification of the com- 
pound. 

-Found.- 


Ortbhorhombic Calculated for 

. Thin plates. crystals, Cs,HgBrols. 
Cesium eo s30e7 1 30°20 30°23 
Mercury .-- 24:14 23°86 22°73 
Bromine. = 2221-05 17°91 18°18 
odines 5522-24-28 28°50 28°86 
100°13 100°47 100:°00 


It is noticable that the plates, which resemble the bromide 
in form, contain a small excess of bromine and a correspond- 
ing deficiency of iodine. 

CsHg BrI,—Only one form of this compound has been 
prepared, although three other salts of this type are di- 
morphous. Its form is monoclinic, like one modification of 
the bromide, and it is pale yellow in color. 


Calculated for 


Found. CsHgBrly. 
Czesiumeee eee ee 20226 19°94 
NECK CUI eee 31°44 29°99 
Bromine ee sen pe ee 13°35 11°99 
lodineta ss Skee ere. 34°39 38°08 

99°44 i 100°00 


The Chloro-iodide, Cs,Hg Cl,I,. 


This is the only combination of cesium chloride and mer- 
euric iodide that could be produced. It is formed only in 
very concentrated solutions containing a great excess of 
cesium chloride. Its form is different from any other salt of 
the type, for it occurs in slender, radiating needles. It is 
snow-white in color, and when it is brought in contact with 
water it instantly becomes bright red from the formation of 
mercuric iodide. Two entirely separate crops were analyzed. 


236 A. FE. Barlow-—Relations of the 


Caleulated for 


Found. CsHgClols. 
Ossimmee 4a eee 33°38 32°14 33°63 
INcr eu, se eles 26°71 nies 25°28 
Chlorine" =e 8°87 9-OL S'98 
Ifoe ie eases es eR 30°85 30°17 Bei Uh 
99°81 100°00 


When it was attempted to make a chloro-iodide containing 
more mercuric iodide than this, a nearly pure double-iodide 
was formed by exchange of halogens. 

Calculated for 


Found. CseHe sls. 
Cees eee ee 13°76 14°13 
IMC CU e222 — eee 33°49 31-88 
Cilonine 222 eee u'16 » 0:00 
lodine 222224 50°74 53°99 

98°15- 100°00 


The investigation of double-halides will be continued in this 
taboratory, and it is hoped that a further study of the cesium 
salts will lead to a better knowledge of this class of compounds 
jn general than we now possess. 

In conclusion, it gives me pleasure to express my gratitude 
to my colleague, Professor Penfield, for his hearty coéperation 
in undertaking the crystallographic examination of the com- 
pounds which have been described. His results have been 
freely used in the foregoing descriptions, and they will be 
given in detail in a future article. 


Sheffield Scientific School, New Haven, 
Conn., May, 1892. 


Art. XX X.—QOn the relations of the Laurentian and Huron- 
wan on the North Side of Lake Huron; by ALFRED E. 
BARLOW. 


[Published by permission of Dr. Selwyn, Director, Geological Survey of Canada. ] 


In this Journal for March, 1892, there appears an article on 
“The Structural Relations of the Huronian and Basement 
Complex on the North side of Lake Huron” by Messrs. Pum- 
pelly and Van Hise. On page 228 they refer to an article by 
me “On the Contact between the Laurentian and Huronian 
north of Lake Huron” which was published in the American 
Geologist (vol. vi, 1890, pp. 19-32). The region to which 
my paper referred might better have been defined as north-east 
rather than north, as the descriptions related only to certain 


Laurentian and Huronian of Lake Huron. 237 


portions of the line of junction between Lakes Temiscaming 
and Panache, the latter locality being over one hundred miles 
east of Thessalon, near which Messrs. Pumpelly and Van Hise 
observed the contact. The endeavor to correlate two series of 
facts concerning rocks so far separated geographically after a 
brief and hurried visit and over a limited area has only led to 
more confusion and misunderstanding. Their description of 
the line of junction between the ovanite and erystalline schists 
is a feature very frequently observed in the Laurentian (or 
basement complex). These schists, however, do not in the 
least resemble the micaceous schists and quartzites described by 
me as Huronian in contact with the Laurentian gneiss, for those 
described by Pumpelly and Van Hise show no clastic structure 
whatever and seem always to belong to the basement complex 
(Laurentian) with which they are associated, while the fra 

mental origin of those described by me may readily be seen in fe 
field or in thin slice under the microscope. Beautiful examples 
of the mode of occurrence of the Laurentian schists may be 
seen at the Murray Mine,on the main line of the Canadian Pacifie 


Railway, three Tue and a half northwest of Sudbury. Here 
the hornblende schists or amphibolites are seen embedded in a 
light colored gneissic granite, the pseudo-conglomeratic appear- 
ance thus produced being sometimes very marked. (See Fig. 1). 
In other cases the hornblende schists occur in lenticular patches 
lying parallel to one another. (See Fig. 2.) Prof. G. H. Williams 
(see Report Geological Survey of ohare Bart; Hy S8ou pd) 
classes these amphibolites « among the undoubted eruptives and 
thus describes them: ‘A fine grained, very dark green or 
nearly black foliated rock containing a much coarser felspathic 
or granitic vein. This is a closely interwoven ageregate of 


238 A. & Barlow—felations of the Laurentean, ete. 


green hornblende and brown biotite. The foliation is produced 
by the approximate parallelism in the cleavage directions of the 
minerals. The only other constituents visible under the micro- 
scope are quartz and ilmenite surrounded by veins of sphene 
(leucoxene). Of the origin of this rock we can say nothing 
now with certainty. It may well have resulted from the ex- 


bo 


treme metamorphism of some basic eruptive, but from a small 
specimen like this it is unsafe to draw any such conclusion. 
The feldspathie vein is a much coarser aggregate of quartz, 
orthoelase and plagioclase with a little green hornblende. The 
feldspar has many minute hornblende needles secondarily devel- 
oped in it, but otherwise the rock appears like a fresh granite.” 

The eruptive origin assigned to this rock by Prof. Williams 
would seem to agree with its relations in the field and on ac- 
count of its intimate association with granitoid gneisses we 
have classed it with the Laurentian and so colored it on the 
recent maps issued by the Canadian Survey of the Sudbury 
Mining District. These gentlemen also make me state that I 
‘drew the conclusion that nowhere on the north shore of Lake 
Huron are any detritals which are later than and rest uncon- 
formably upon the basement complex,’ when in the article is 
distinctly described (see p. 87, American Geologist, Vol. VI, 
1890) a thinly bedded slate conglomerate resting upon the up- 
turned edges of the Laurentian gneiss on Annima- Nipissing 
Lake. 

Briefly then, the Huronian System may be regarded as the 
oldest séries of sedimentary strata of which we have at present 
any knowledge in this district, while the Laurentian gneiss or 
basement complex is the original erust of the earth or the firm 
floor on which the first sediments were laid down. The com- 
position of this floor, judging from the overlying strata, would 
be closely analogous. to granite and the laminated pebbles in 
the slate conglomerates indicates that this basement had in 


F. A. Gooch—Forms of Laboratory Apparatus. 239 


many places a foliated or gneissic structure. The immense 
pressure exerted by the overlying stratiform material, and the 
erumpling folding and fracturing of the comparatively thin 
and weak crust consequent on the earth’s cooling would all 
tend to sink large portions of the Huronian below the line of 
fusion, the submergence of which would produce conditions of 
contact such as I have described to the north-east of Lake 
Huron and which subsequent upheaval and denudation have 
exposed. 

At other places the basement complex may have remained 
undisturbed so that the overlying detritals though somewhat 
altered have not been intruded or pierced by the granitic mass 
beneath. The latter doubtless have been the conditions which 
obtained in the localities visited by Messrs. Pumpelly and Van 
Hise north of Lake Huron and by me on Annima-Nipissing 
Lake. The explorations of the past two seasons have served to 
confirm the opinions expressed in the paper published in the 
American Geologist and as the region then under examination 
has just been finished, I hope to move farther west during 
the coming summer and explore the district visited by these: 
geologists. 

Before closing I would like to take exception to the various 
brief visits paid to certain so-called “typical localities,” as the 
hurried examinations thus made must always lead to confusion. 
Had Messrs. Pumpelly and Van Hise written to me I would 
have been only too eager to accompany them to the many points 
of geological interest exhibited in this district. It is often so 
easy then to reconcile seemingly opposite views, whereas a 
letter in reply, no matter how written, only leads to endless 
and sometimes useless discussion. 


Art. XXXI.—Some Convenient Forms of Laboratory Appa- 
ratus ; by F. A. Gooc#. 


[Contributions from the’ Kent Chemical Laboratory of Yale College—XVI.] 


Burette Clip.—A simple and effective device to replace the 
Erdmann float (which has well-known disadvantages) in getting 
exact burette readings is made by cutting thin springy brass, 
or copper, or other metal to the form of a letter Hj, shaping it 
as shown in fig. 1 so that it will cling to a burette with the 
cross-bar vertical, and fastening to the cross-bar a fold of white 
paper ruled longitudinally with a heavy, sharply defined, dark 
line. The clip may be made to hold firmly to any burette, 
while capable of easy upward and downward motion, and is 


240 F-. A. Gooch 


forms of Laboratory Apparatus. 


readily removable and replaceable when it be- 
comes necessary to pass the point of support of 
the burette. The refractive action of the 
meniscus upon the dark line upon the white 
background acts just as in the enamelled 
burettes which have recently come into use, and 
serves to define exactly the level of the liquid. 
Errors of parallax in observing are easily avoided 
by placing the eye in such position before read- 
ing that the front segment of the circle nearly 
completed by the edge of the upper ring falls 
into coincidence in perspective with the back 
segment as shown in the figure. 

Apparatus support.—The simple device illus- 
trated in fig. 2 and fig. 3 has been in use for several 
years in this laboratory wherever a rod support is 
desirable and ‘has almost entirely replaced the 
movable stand which students usually find un- 
wieldy and difficult to dispose of in limited 
space. The brass fitting into which is cut a 
strong screw thread, as shown in fig. 2, is set 
directly in the face of the work table with its 

~ upper surface flush with that of the table, and 
is held in place firmly by screws if the table-top is of wood, or 
by bolts and nuts if the tabletop is of soapstone or other 
material which does not afford holding ground for ordinary 
screws. Iron rods of sizes and lengths suited to holding all 
sorts of apparatus, from the lighter 
forms used in elementary laboratory 
instruction to the heavier lecture appa- 
ratus, are cut with screws matching the 
thread of the brass fitting and may be set 
firmly in place as shown in the figures. 
The rods are of course interchange- 
able as occasion may require. When 
stripped of apparatus the rod takes up very little 
table space, but if a clear table is desired, it is 
easy to remove the rod by means of tongs kept 
at hand for the purpose in the laboratory tool- 
box. This device is neat, inexpensive, and 

is easily made by any worker in brass and iron. 

Steam evaporator.—A convenient, simple and inexpensive 
form of individual steam-bowl is easily constructed in the 
form shown in fig. 4 wherever steam connections are available. 
An ordinary glass funnel of suitable size is hung in an iron 
ring, for holding which the rod support previously described 
serves admirably. The stem of the funnel is cut off short and 
a T-tube is attached as shown, set in a short piece of rubber tub- 


( 
I) = 


TTA 


FE. A, Gooch—Forms of Laboratory Apparatus. 241 


ing, with the lower end of the vertical branch bent to make a 
water-trap, while the horizontal branch is connected with the 
steam supply. A pipe to convey away the condensed water 
which overflows from the trap is a convenience, but in the 
absence of a drip-pipe any suitable receptacle 
may serve a similar purpose. Ordinary 
water-bath rings adapt the funnel to vessels 
of various sizes, but the funnel itself serves 
efficiently in holding several different sizes 
of round-bottomed dishes. The transparency 
of the funnel makes it possible to regulate 
the steam supply so as to secure the maxi. 
mum heating effect without saturating the 
surrounding atmosphere with waste steam. 
Of course, if it is desirable, several of these 
steam-baths may be hung to the same rod. 
Mercury washer.—Various forms of mercury-washing ma- 
chines have been proposed and used with success. The par- 
ticular form here described and shown in fig. 5, differs essen- 
tially from its predecessors only in the degree of fineness to 
which the impure mercury is reduced when it is brought into 
contact with the purifying medium. In this apparatus the 
impure mercury, liquid enough to flow readily, runs of its 
own weight from the uppermost funnel through the supply 
arm of a glass atomizer through the other arm of which com- 
pressed air is admitted in force sufficient to break the thin 
stream of mercury to 
fine dust. Thus thor- 
oughly comminuted, 
and presenting the max- 
imum surface to the 
liquid, the mercury 
falls into dilute nitric 
acid, from which it 
passes to distilled water, 
and thence to the dry 
receiver. Funnels’ 
fitted with outlet tubes 
set in rubber stoppers, 
as shown in the figure 
answer well for contain- 
ing vessels, and the 
rod and socket device 
described above serves 
as a support for the 
apparatus. In the case 
of the particular appa- 
ratus which I have used 


AM. Jour. Sci1.—THIRD SERIES, VOL. 
16 


LIV, No. 261.—SEPTEMBER, 1892. 


242 Barus and Lddings—Electric conductivity observed 
the air was admitted to the atomizer under a pressure of about 
one-third of an atmosphere above the ordinary. 

Certain experiments made to determine whether ferric 
chloride or chromic acid might be used in the purifier instead 
of dilute nitric acid showed that the superficial effect of these 
reagents upon the extremely finely comminuted mereury pre- 
vents the reunion of the particles even when submitted to 
considerable pressure. When dilute nitric acid is employed 
no such difficulty arises. 


Art. XX XII.—Wote on the change of electric conductivity 
observed in rock magmas of different composition on pass- 
ing from liquid to solid; by Cari Barus and JosepH P. 
IDDINGS. 


[Published by permission of the Director of the U. S. Geological Survey. ] 


§ 1. Introduction.—The chemical composition of rock mag- 
mas and the process and results of their crystallization and 
solidification have been studied with more or less thoroughness ; 
but direct investigation of their physical properties has not been 
systematically undertaken until recently. 

Conceptions of the physical nature of molten rock magmas, 
however, have been obtained by observing the phenomena of 
their crystallization, and by pointing out analogies between the 
latter and the behavior of aqueous solutions, and of metallic 
alloys. 

Evidences that a chemico-physical -differentiation of molten 
magmas was the cause of chemical differences in igneous rocks, 
which evidences have been reviewed by one of us in a paper on 
the origin of such rocks,* have led to the further analogy 
between this process of differentiation and the concentration 
and partial dissociation of salts in aqueous solution. They also 
suggested the possibility of testing the fact of dissociation by 
electrolytic investigation. 

The method employed was the detenminanion of the electric 
resistance encountered by a current in passing through fused 
rock magma, whose temperature was gradually lowered. The 
investigation, though of a preliminary character has been pro- 
ductive of such definite results that we have embodied them 
in the present paper in order that they may become known as 
early as possible. 

§ 2. Observations.—The following table contains typical ex- 


*J. P. Iddings. The origin of igneous rocks, Bull. Phil. Soc. Washington, 8 
Washington, 1892, vol. xii, pp. 89-214. 


in Rock Magmas on passing from liquid to solid. 248 


amples of sixteen series of electric measurements made with 
three kinds of rock magmas, which cooled slowly in a furnace 
from the molten state. Temperatures* and resistances were 
noted simultaneously every two minutes during each series. 
The resistances were measured by Kohlrausch’s method of 
intermittent currents. The data for mean temperatures are 
closely accordant, but at very high temperatures and at low 
temperature sharpness is lost, owing to polarization and to the 
immense range of electrolytic resistances encountered. These 
difficulties are largely unavoidable, although our method is 
capable of much improvement. Reductions to absolute values 
are approximate. 


TABLE I. 


Table 1. The specific electrolytic resistances of rock magmas, varying with tempera- 
ture and composition. 


1. Acid magma. | 2. Intermediate magma. | - 3. Basic magma. 
75°50 per cent SiOz. | 61°5 per cent SiOs. 48°5 per cent SiO». 


Tem- - 
Series. perature. Resistance. (Series. perature. Resistance. | Series. perature. Resistance. 


Rive, ohmes< O° xa ohms x 10° vill °C ohms X<10° 


1640 1°8| 1430 1:8) 1400 2°9 
1320 2-2) 1260 2°5) 1230 . 4-4 
1164 2°9. 1114 4:9) 1124 5:4 
1086 3:1 1034 6'3 1050 14:7 
1011 3°8) 956 8:8] 995 27'8 
948 4-7 894 13°4| 939 54°7 
890 65. 843 20°0. 883 94+() 
827 8:0 754 46°4, 834 152 
OMe 11°6 715 70°2 792 227 
746 15°3| 680 105 | 754 321 
705 21°6 643 158 | 723 432 
665 29:5) 608 239 692 602 
626 41°3 580 344 645 1000 
598 53°83 552 497 | 612 1400 
582 64:2, 496 1140 

560 82°2 

533 114 

504 UGE: | | 

467 281 | | 

444 A417 | 

425 584 | | 

395 1060 | | 

3552 25404 | 

320 5700 | 


The results of these observations have been plotted as in 
the diagram, fig. 1, the ordinates being specific resistances in 


* Regarding temperature measurements see Phil. Mag., July, p. 1, 1892. 


244 Barus and [ddings—Electric conductivity observed 


megohms, the abscisse temperatures in °C. The curves 
(which, as shown, contain a@// our observations) are numbered 
(1), (2), (3), as in Table I, relatively to the magmas. Between 
1000° and 1500° the points lie so near the axis, that a diserimi- 


_A)7Zn SOn+A 


[Sp Resist 


0" 500" 7 1000s 1500" 
Legends. 


Fig. 1. Chart showing the relation of the specific electrolytic resistance 
(megohms, cc) to Temperature (°C), in case of 

(1) An acid magma, 

(2) An intermediate magma, 

(3) A basic magma. 

(4) Zine sulphate, concentrated aqueous solution. Resistance relative. 
Fic. 2. Crucible and appurtenances with the furnace withdrawn: 

aaa, rock magma in platinum crucible; 

, tubular platinum electrode; 

7, insulator (fire clay) of the thermocouple ; 

af, thermocouple with its junction ato: 

ee’, electrolytic current (intermittent). 


nation is no longer possible. This can be done, however, by 
expressing the variations of conductivity with temperature for 
the interval. It is here omitted because it leads to no novel- 
ties. The corresponding curve for a concentrated solution of 


in Rock Magmas on passing from liquid to solid. 245 


zinc sulphate in water has been added for comparison. Here 
the ordinates are ratios in terms of the resistance of the solu- 
tion at 100°. Points above 100° were obtained under pressure. 
Fig. 2 explains itself. 

A series of observations with another basic magma gave 
corroborative evidence. The only electrical indication of 
fusion was found in the case of the basalt (3). It was some- 
what above 1100°, but is not certain. The rhyolitic or 
acid magma (1) changes character suddenly below 500°, for 
reasons probably accidental which must be further examined. 
In this rock, which is very viscous even at 1600°, it is almost 
impossible to free the magma of gas bubbles. We have not 
been able to make allowance for volume expansion of the 
magma, and the residual errors are in keeping with this omis- 
sion. Finally, without sacrificing accuracy of temperature 
measurement, it is difficult to make the electrodes sufficiently 
large in area to exclude polarization. 

$3. Lhe magmas.—The magmas investigated represent 
three phases of igneous rocks from the same region. The 
first is a rhyolite; the second, a erystalline andesite or por- 
phyrite ; and the third, a basalt. The chemical composition of 
the rocks is shown by the following analyses made aM Mr. J. E. 
Whittield. 


If, IDL; It. 


Si Ome eu aes Jf 75.50 61°50 48°49 
AD ORR esta ee Sareea oe none none 2°19 
One aS 13°25 17°42 18.35 
COPE sie ea haw 1°02 4°66 7°63 
Re Oey aa ns 291 1°09 1°21 
JY aK Os Ca ea le none tr. none 
CAO Aa Mes ee seca ‘90 5°33 10°40 
Me One! se ne 07 1:26 6°72 
RO) See een ere 1306 "038 02 
Nar Os ee ea 4°76 3-99 3-02 
FRE Oe A ae 2°85 1:29 57 
yA OA Fer ase teas ata none 60 "20 
SO ei ie a. 289 35 52 
EO) eCity ‘41 2°44 67 

100°05 99.96 99°99 


‘The three magmas clearly form the middle and extremes of 
a chemical series. 

When heated in a platinum crucible, the basalt melts at 
about 1250° to a fluid which at slightly higher temperatures 
becomes quite liquid, and upon solidification forms a black 
glass that is brown in the thinnest edges and is without gas 
bubbles. 


246 Barus and Iddings—E lectric conductivity observed 


The porphyrite when heated decrepitates, and afterward 
fuses in the neighborhood of 1400°, but does not become as 
liquid as the basalt for like temperatures. It solidifies as a 
dark brown glass with some gas bubbles. 

The rhyolite melts at about 1500°, but remains quite viscid 
at 1700°, and solidifies as a gray glass filled with minute gas 
bubbles. 

The amount of gas bubbles serves as an indication of the 
relative viscosity of the different magmas at the temperatures 
to which they were subjected. 

§ 4. elation to temperature.—In making the present de- 
ductions the outspoken parts of the data of Table I can alone 
be taken, viz: in case of the magma (1) between 900° and 
500°; in case of (2) below 1034°, and in case of (38) between 
1124° and 692°. Careful scrutiny of the relation of resistance 
to temperature then shows, that the ratio, d7/dt, of correspond- 
ing decrements of specific resistance, —dr, and of temperature, 
dt, is proportional to the corresponding resistance at the given 
temperature. In other words we have — 7’ = a + bt, whence 


tila. Ory Se 00 Se eS (1) 


where a, 6, c, are constants. Relative to Table I these values 
are approximately (7 in megohms) 


(1) (2) (3) 
0) en Ue A ORE —'10 — 05 +°05 
(ES SR a 28 0134 "0125 ‘0091 
Gite peter Waa Dae 7°59 8°78 7:96 


It is probable that a merely reflects the errors of observation 
and that its real value is zero. The constant 0, which is an 
index of the composition will be discussed in $$ 5,6. The 
quantity ¢/b, which is a temperature, has no apparent meaning. 
These results are exceedingly interesting since a relation simi- 
lar to equation (1) was found* for the thermal variation of the 
viscosity of a highly viscous body like pitch. Again the acid 
magmas at least, betray no evidences of circumflexure, or any- 
thing that would be an electrical index of polymerism or melt- 
ing point. An aqueous solution of zine sulphate carried 
under pressure through a large interval of temperature, shows 
changes of resistancet+ quite akin to the present. In both 
cases, therefore, we have similar solution phenomena, exhibit- 
ing a thoroughly regular change of the electrical character 
with temperature. 

Moreover the nature of the law embodied in equation (1), 
for silicates, the enormous range of temperatures to which they 


* Proc. Am. Acad., xxvii, p. 13, 1892. 
+ This Journal, xlii, p. 135, 1891. 


in Rock Magmas on passing from liquid to solid. 247 


can be exposed, the extreme sensitiveness of the electrical 
indications, and the simplicity of the necessary apparatus, 
suggest a method of pyrometry specially available for tempe- 
rature approaching the melting point of platinum. One 
would obviously select an exceedingly acid magma, both be- 
cause of its relatively great infusibility, and because of the 
occurrence of the maximum of uniform electrical conduction, 
in such a ease, as will be shown in the next paragraphs. 

§ 5. Relations to chemical composition. — Endeavoring to 
interpret these results with reference to their chemical bear- 
ing by means of Kohlrausch’s* law we are handicapped at the 
outset because the rates of procession of ions (Hittorf’s 
“ Uberfithrungszahlen ”’) in silicate solutions are not known. 
In other words the quantities expressing the velocity of either 
ion relative to the combined velocities of both are unknown. 
We cannot even state what the structure of the electrochem- 
ical equivalents may be. It makes a difference whether the 
cations travel singly or in groups, or whether the anions be 
$810,, 4510,, ete., singly or combined. We could not there- 
fore express more than a mere opinion relative to the velocities 
of the ions, even if the specific molecular conductivities were 
computed. Nevertheless, in the face of these difficulties we 
are able to deduce certain striking results insomuch as the 
method of this paper is one in which the cation is brought 
gradually, and as nearly as possible to vanish in amount. An 
index of acidity, independent of temperature, is given by the 
constant > of equation (1). We regard the anions, whatever 
their specific structure may be, as identical in the three mag- 
mas examined; and the cations, from the large number of 
elements contained in the magmas, as possessed of a common 
or average property. 

Several general deductions, however, may be drawn from 
the work, incomplete as it is at present. In the first place, 
Table I shows strikingly that electric conduction increases with 
the degree of the acidity of the magma, that is, with the 
degree of dilution of the cation. And since fusibility de- 
creases in a marked way as the composition of the magma 
approaches pure silica, it follows that in a series of different 
magmas electric conduction at any given temperature increases 
im proportion as the viscosity increases. 

Thus the most acid of the rocks investigated, (1), is a stiff 
paste above 1500,° whereas the basalt, (3), can be poured at a 
temperature much below 1800°*; and yet the rhyolite, in vir- 
tue of its acidity is a better conductor than basalt at any given 
temperature. 


* Kohlrausch, Wied. Ann., vi, pp. 145 et seq., 1879. 


248 Barus and Iddings—Electric conductivity, ete. 


The table also shows that the conductivity of rock magmas 
at high temperatures is considerable even when they have 
passed from a liquid to a solid state, that is, when they exist 
as highly heated glasses. 

In general, therefore, a thorough change of chemical strue- 
ture through ionic diffusion, whet! ier directed by an electrical 
field or otherwise, must be an easy possibility in a sufficiently 
temperatured but otherwise solid magma. 

§ 6. The second point gained is more specific. Kohlrausch* 
has shown that the contribution of a single ion in promoting 
electrical conductivity decreases with the number of ions pres- 
ent. In other words in concentrated solutions the ions are 
stopped en route by what may be termed friction, but what is 
probably temporary intercombination with each other. Hence 
their mean velocity, and consequently the specific molecular 
conductivity of the solution falls short of the proportionate 
quantity. Moreover, it is perfectly well knownt that many 
solutions (H,SO,, HCl, ZnSO, etc.) show maxima of electric 
conductivity for gradual changes of concentration. The case 
of an aqueous electrolyte decreasing in electric conductivity 
with increasing concentration is therefore given by many ex- 
amples, and doubtless their number could be indefinitely 
increased by employing aqueous solutions at high temperatures 
under pressure. 

Now this is exactly what we observe in our series of three 
silicate solutions. Conduction increases markedly from (8) to 
(1), that is, from basic to acid, and it seems altogether probable 
that the anticipative maximum will correspond to a degree of 
silicic dilution greater than 75 per cent of silica. 

Tracing this inference further we come to the conclusion 
that pure silica is probably an insulator, or that it occupies a 
position in siliceous electrolysis very closel y analogous to that 
of water in aqueous electrolysis. It is to be remarked that we 
here refer to the electrolytic solvent and leave the question of 
chemical solvent temporarily out of consideration. This is in 
accord with the observations of Warburg,t who has elaborately 
investigated the insulation of a film of pure silica at about 800,° 
the film having been produced by the electrolysis of glass. 
The insulator was found to be so perfect that the capacity of 
the ras was measureable. The insulation of quartz 
relative to glass has to some extent (as far as 224°) been tested 
by Warburg and Tegetmeier,$ though the conditions were 
complicated in this instance both by erystalline structure and 
the impurity of the mineral. 

* Kohlrausch, l. c. p. 183. {leap aa3e 


¢ Warburg, Wied. Ann., xxi, p. 622, 1884. 
§ Warburg and Tegetmeier, Wied. Ann., xxxv, p. 463, 466, 1888. 


Lea—Estimation and Dehydration of Silver Oxide. 249 


§ 7. Conelusion.—Looking at our results as a whole we find 
them Eakins in a novel way on the solution theories of 
Arrhenius, Ostwald and vant? Hoff. It is difficult to withhold 
one’s assent from the proposition, that the ions of a molten 
magma are largely present in the dissociated state, and more 
especially so as we approach very acid: magmas. Terms like 
colloid applied to these magmas are absolutely without rele- 
vancy so faras we can make out. ‘To the extent of our enquiry, 
the behavior of molten rock magmas is in its nature quite iden- 
tical with that of any aqueous or other solution, the difference 
being one of solvent. 

The above paragraphs give a mere draft of a series of ex- 
periments which we propose to carry out with greater vigor. 
We desire, however, to express our conviction that electro- 
lytic resistance is not only a valuable aid to petrological 
research, but that the detinition of molecular structure is 
possibly within the reach of the method. 


Art. XXXIII.—Hstimation and Dehydration of Silver 
Oxide; by M. Carry LE. 


In some analytical determinations it became necessary to 
estimate silver oxide and the question arose at what tempera- 
ture the moist oxide could be perfectly dried, and also at what 
temperature it began to lose oxygen. As no such data are to 
be found, they had to be determined, and the results obtained - 
may possibly be of use to others. 

Moist oxide precipitated by perfectly pure sodium hydrate 
obtained from metallic sodium, and thoroughly washed, was 
dried at 100° C. for 20 hours. Of this material 1°5528 grams 
was taken and heated again to 100° for 20 more hours, after 
which heating it. weighed 1:5524, a loss of 0:0004 grams. 
It was next heated to 160°-165° C. for five hours and was 
then found to weigh’ 15389 grams, a loss of 0-0185 gram. 
It was then replaced in the oven and heated 5 more hours. 
No loss whatever of weight could be detected resulting from 
this second heating. The oxide was then ignited and gave 
14358 grams of silver. 

Taking the atomic weight of silver at 107-66 and O = 16 
argentic oxide should contain 6-92 per cent of oxygen (more 
exactly 6-917). 

From the foregoing it follows that moist silver 
oxide dried for 40 hours at 100° lost by 


SADNAGKOIMN £y aes ¢ ee os eae ee A es ed grt Bh ae 7°51 per cent 
The same oxidé with 10 hours drying, at 160°- 

UGS pe CalOste YAO ONION e255 aaa oe 6°70 ss 
Calculation for Ag,O gives for O __.-.--.-.-.-- 6°92 i 


250 Scientific Intelligence. 


It follows that after 40 hours drying at 100° the oxide has 
reached a constant weight and still retained 0°59 per cent of 
moisture. Mien heated to 160—165° till constant in weight it 
had lost 0:22 per cent of oxygen. 

It was next attempted by a shorter second heating and a 
lower temperature to expel the water alone. Silver oxide was 
dried for 20 hours at 100° and was then heated for 2 hours to 
130°-185° C. Of this oxide 1:8043 gram was ignited and 
left 16701 gram of silver, indicating a loss by ignition of 
7-44 per cent. This was only ‘07 less than when the heat was 
not raised above 100° C., showing that the oxide is not dehy- 
drated by exposure to a temperature of 180°-135° C. 

The conclusion to be drawn would apparently be that the 
point at which the last portions of water were driven off was 
very close to that at which oxygen began to be disengaged. 
It can be shown however that this is not so and that oxygen 1s 
lost long before the last portions of water escape. This can be 
proved by the delicate photochloride reaction which I de- 
seribed some years ago. If the silver oxide, dried as above 
described at 100° © till it reaches a constant weight, is 
moistened with dilute hydrochloric acid, a chloride is obtained 
of a deep lilac color. This color always denotes the presence 
of hemichloride due to the fact that a certain portion of the 
oxide had been reduced to hemioxide. The hemichloride 
combining with the white chloride forms a photochloride char- 
acterized by the coloration just mentioned. 

A really accurate estimation of silver oxide is therefore im- 
‘possible, as it loses oxygen too easily. 

Silver oxide is not supposed to form a hydrate, nevertheless 
some portion of moisture remains united with it more strongly 
than some part of the oxygen with which it combines to form 

a strong base. 

But it also appears that the loss of oxygen is very small and 
soon ceases even at 160°-165° CO. For after 5 hours exposure 
to that temperature, the weight became constant. 


S CPE N LITE EC. IN WE Ee hesheNeC see 


I. CHEMISTRY AND PHYSICS. 


1. On the Phenomena of Coal-dust Hxplosions.—THORPE has 
described a lecture experiment to illustrate the phenomena which 
are observed in explosions wherein light combustible solids like 
coal dust suspended in the air are the chief combustibles. In coal 
mines opinions are divided as to whether coal dust alone in the 
air can give rise to explosions, or whether it can do so only when 


Chemistry and Physics. 251 


mixed with fire damp. The apparatus employed by Thorpe con- 
sists of a narrow box of wood 12 feet long and 5 inches square 
intersected at its middle point by a second similar box 6 ft. long. 
Both boxes are open at the ends and are provided with lids 
attached with strong hinges and hasps. They are made of inch 
oak and are put together with screws. At one end of the long 
box isaslide; and the end itself fits into a quadrangular box 9 
inches square, furnished with a lid on top and asmall hole for 
the introduction of a tube carrying gas. On delivering into the 
box such an amount of gas as will make an explosive mixture 
(best from a graduated bell-jar over water) and on strewing coal 
dust along the entire length of the boxes, a blank cartridge, fired 
from a pistol through the lid of the box to illustrate the effect of 
a blast, raised a dust cloud which ignited by the explosion, projects 
a flame several feet long from the farther end of the box. To 
illustrate a local explosion of fire damp, the slide at the end of 
the box is pushed in and an explosive mixture is made in the box 
beyond it. The slide is then withdrawn and a match applied. 
The explosion raises a cloud of dust and this by its violent igni- 
tion produces a continuous cloud along the whole length of the 
box which is driven out four or five feet from the remote end. 
Little heaps of gunpowder, or pieces of touch paper placed at 
intervals along the box, are rarely fired.—J. Chem. Soe., |xi, 414, 
May, 1892. G. F. B. 
2. On certain New forms of Carbon.—A new variety of car- 
bon has been obtained by Luzi. When a piece of porcelain, such 
as a crucible or crucible-cover, is heated in a blast furnace to the 
highest attainable temperature, say to 1770° C., the fusing point of 
platinum, and then the access of air is cut off, the highly heated 
porcelain is surrounded by a smoky flame, which is allowed to act 
upon it for ten or fifteen minutes. On removing the piece of 
porcelain from the furnace, it is found to be covered with a 
peculiar deposit of carbon. If it was unglazed, the deposited 
carbon resembles graphite; but if glazed, the deposit is bright 
and silvery and has a metallic luster, resembling closely a silvered 
mirror. Portions of the deposit adhere so firmly that they can 
be polished with a cloth ; others separate in the form of mirror- 
like facets of high luster. Loose portions can be pulled off; and 
then they curl up into rolls like metal shavings. ‘They are ex- 
ceedingly light and stick to the fingers like silver leaf. This form 
of carbon is free from ash and does not contain hydrogen; nor 
does it give the nitric acid reaction for graphite. Moreover it is 
absolutely opaque. The author has also examined 17 additional 
varieties of natural graphite by his nitric acid reaction. Nine of 
these give the reaction and are therefore graphite proper; eight 
do not and are therefore included in the second class which he 
calls graphitite. Of the 31 specimens thus far examined 16 were 
graphite and 15 graphitite. The blackish-gray substance into 
which diamond is converted on heating, and which resembles 
graphite, did not give the nitric acid reaction.— Ber. Berl. Chem. 
Ges. xxv, 214, February, 1892. Ga Ee B: 


252 Scientific Intelligence. 


3. On Quinite, the simplest Sugar of the Inosite group.— 
Since Maquenne proved inosite to be a six-fold hydroxylized 
hexamethylene, it was to be expected that the hydroxyl deriva- 
tives of this substance which are poorer in oxygen would possess 
sugar-like properties. BagyER has now succeeded in reducing 
the p-diketone of hexamethylene by means of sodium amalgam 
to the glycol of hexamethylene. To purify it, he converted it 
into the diacetyl derivative and this on saponification with barium 
hydrate gave the pure glycol, C,H,,O,. It is cistrans-paradioxy- 
hexamethylene and resembles in appearance and behavior a sugar 
of the mannite group. It is permanent toward permanganate 
solution and Fehling’s solution, tastes at first sweet and then 
bitter. It is easily soluble in water and alcohol, fuses at 143°— 
145°, and distils without decomposition. According to its forma- 
tion it is a hexahydro-hydroquinone, and in that case would afford 
on heating with chromic acid quinone. Since it possesses sugar- 
like properties and is the simplest representative of the inosite 
group, the author proposes for it the name-.gwinite. ‘The prepara- 
tion of this substance opens the way apparently for the produc- 
tion of other hydrobenzene compounds.— Ber. Berl. Chem. Ges., 
xxv, 1037, March, 1892. G. F. B. 

4. On the Relation between the Color of Compounds. and 
their Chemical Constitution.—From an extended study of a large 
number of colored compounds both organic and _ inorganie, 
ScuttTzeE has obtained some results going to show a relation be- 
tween the color of these substances and their chemical constitu- 
tion. These results he sums up as follows: (1) A displacement 
of the absorption from the violet toward the red corresponds to 
the color-changes greenish-yellow, yellow, orange, red, reddish- 
violet, violet, blue-violet, blue, blue-green, ete.; this order of 
change being called “ lowering the tint.” A displacement from 
red to violet corresponds to an inverse color change, i. e., to a 
“raising of the tint.” (2) Atoms and atomic groups on entering 
a molecule produce, for compounds of the same chromophore and 
for the same solvent, a characteristic lowering of color-tint 
(bathochromic groups) or a raising of the color tint (hypsochro- 
mic groups). (3) Hydrocarbon radicals act always bathochromic; 
so that in homologous series the shade deepens as the molecular 
mass rises. (4) The color-changing action of the elements of the 
same periodic group also increases with an increase in the atomic 
mass.. (5) Addition of hydrogen is always accompanied by a 
raising of thetint. (6) The raising or lowering of the color-tint 
(displacement of the absorption toward the violet or the red) by 
the substitution of hypsochromic or bathochromic groups, or by 
the addition or removal of hydrogen, is the more decided the 
nearer the chemical change which takes place is to the chromo- 
phore. In general the distances of the atoms from one another 
given by structural formulas correspond to their actual distances ; 
in some cases, however, it appears that as in the di-derivatives of 
benzene, the substituents in the para position are nearer to each 


Chemistry and Physics. 253 


other than are those in the meta position. (7) These rules hold 
good only for “monochromophoric”’ compounds and for such 
“ dichromophoric ” ones as have equal color-groups influenced in 
the same way by the neighboring atoms. The color of an unsym- 
metrical diazo-compound of the type Y-A—X-—A-Z is approxi- 
mately the same as that of a mixture of the two symmetrical 
compounds Y-A—X—A-Y and Z—-A-—X-—A-Z.—Zeitschr. physikal. 
Chem., 1x, 109, February, 1892. G. F. B. 
5. On Free Hydroxylamine.—The assumption that hydroxyl- 
amine is not capable of existing free, arose apparently from the 
presence of water in the process employed. Lonry pre BruyNneE 
has now succeeded in isolating it by acting on hydroxylamine 
hydrochloride dissolved in absolute methyl alcohol, with nearly 
the theoretical quantity of a concentrated solution of sodium 
methoxide, at a gentle heat. The sodium chloride produced was 
filtered off and the filtrate was distilled under a pressure of 160- 
200"; since at this reduced pressure the alcohol carried off less 
hydroxylamine. When most of the alcohol had been thus re- 
moved, dry ether was added. This separated the liquid into two 
layers, the upper containing 5°5 per cent hydroxylamine, the lower 
53°5 per cent. The lower layer again distilled under a pressure 
of 165™™ until the temperature rose to 86° gave a solution con- 
taining 70 per cent of hydroxylamine. Finally, all the solutions 
were mixed and distilled under a pressure of 60™". The residue, 
containing 80 per cent of hydroxylamine, was fractionated in 
three portions, the last of which solidified in long needles in the 
cold receiver. This after pressing between filter paper, contained 
99°4 per cent hydroxylamine. In this form it is a hard crystalline 
mass, very hygroscopic and fusing at about 27°5°. Sodium 
chloride readily dissolves in it and potassium nitrate liquefies it, 
so that it resembles water. Sodium attacks it strongly. It is 
inodorous aud somewhat denser than water. When heated rapidly 
on platinum foil it explodes with a clear yellow flame. It is 
scarcely soluble in chloroform, benzene, ether, ethyl acetate or 
carbon disulphide. Exposed to the air it first liquefies and then 
evaporates. It appears to be stable alone as well as in solution. 
—Ree. trav. Chim., x, 100; J. Chem. Soc., |xii, 402, April, 1892. 
Ga) RB: 
7. Physical and chemical phenomena under the influence of 
very low temperatures.—M. Raovuu Picter states that heat-waves 
corresponding to low temperatures traverse all bodies with hardly 
any resistance. A test tube filled with chloroform was placed in 
a nitrous oxide refrigerator at —120°. A thermometer in the 
tube showed a gradual fall to —68°°5, when crystallization com- 
menced. On removing the test tube to a refrigerator at —80°, 
the temperature indicated by the thermometer fell rapidly from 
—68°°5 to —80, while the crystals formed on the walls of the 
test tube fused and disappeared. On replacing it in the —120° 
refrigerator, the temperature rose to —68°-5, and the crystals 
reappeared. M. Pictet explains these phenomena by supposing his 


254 Scientific Intelligence. 


thermometers to have acted as thermo-dynamometers rather than 
thermoscopes. While the crystals were forming in the first 
refrigerator, the radiation from the bulb was neutralized by the 
latent heat given out by the chloroform in crystallizing, whereas 
in the warmer refrigerator the crystals did not form, and radia- 
tion alone was active. Alcohol and sulphuric ether thermometers 
were used, which were checked by thermometers containing dry 
hydrogen at four different pressures.— Comptes Rendus, May 30, 
Nature, June 9, 1892. J.T 
8. New method of determining the specific inductive capacity 
of a dielectric—¥F. T. Trovron and W. E. Litty point 
out that the comparison between the energy of a condenser 
charged with a certain quantity of electricity, first as an air con- 
denser and secondly with a dielectric sheet between the plates, 
shows that the energy in the first case is greater than in the 
second, and therefore the dielectric sheet will be drawn in between 
the plates; for the electric energy of the system being less after 
the introduction of the dielectric than before, work must have 
been done by the electric forces during the operation. The 
amount of this force depends on the specific inductive capacity 
of the dielectric, and by observing this force the specific induc- 
tive capacity may be determined for any given substance. The 
authors describe a method of measurement, and show its applica- 
bility.— Phil. Mag., June, 1892, pp. 529-532. JU 
9. Action of the Klectric discharge on Gases and Vapors. 
C. LupEKina has made a number of experiments to determiné 
whether electrolysis takes place in the action of the electric dis- 
charge on gases and vapors. He concludes that “some of the 
phenomena noted were in part due to true electrolysis. Others 
seem to be ‘thermolysis,’ that is the compounds are simply dis- 
sociated by the heat of the discharge. The predilection of the 
atoms, thus liberated, for electricity of different kinds would 
make them, like pith balls, fly to the pole having the charge 
opposite their own, and thus give the entire phenomenon the 
appearance in all respects of a true electrolysis, while in reality 
there is the greatest possible difference.”— Phil. Mag., June, 1892, 
pp. 521-528. J. T. 
10. Ratio between the Electromagnetic and Electrostatic Units. 
—A new determination has been made by M. H. Asranam of 
the value of v. The method employed was that of measuring 
the capacity of a plane condenser with guard ring in both sys- 
tems. The value obtained was v=299°2 X10°.— Comptes Rendus, 
June 7, 1892. i ite 
11. Influence of Electrification on Cloud Condensation.—Mr. 
Joun AITKEN has studied this subject, using a steam jet—and 
finds that the mere presence of an electrified body has no influ- 
ence on the steam jet. In order to produce the increased density 
the water particles in the jet must be: electrified either by direct 
discharge, or by an inductive discharge, effected either by means 
of a point or a flame. The increased density produced by electri- 


Chemistry and Physics. 255 


fication is due to an increase in the number of water particles in 
the jet, by the electrification presenting the small drops coming 
in contact by their mutual repulsions, in the same manner as the 
water drops in Lord Rayleigh’s experiments with water jets, 
which scatter more when electrified than when not electrified. 
The coalescence of the drops in water jets takes place only 
under the disturbance produced by the presence of an electrified 
body, while such a disturbance produces no effect on steam jets. 
The action of electricity does not seem to be positive, as it has no 
effect on a mixture of hot moist air and cold air. It seems rather 
to prevent something which takes place in the jet under ordinary 
conditions. ‘The jet on becoming dense emits a peculiar sound 
which is the same whatever be the cause of the increased density. 
But when electrified, along with this sound there is another, due to 
the discharge of the electricity, which causes the electrified jet to 
appear to,make a louder noise.—Royal Society, April 28, 1892; 
Nature, May 26, 1892. JaeT 
12. The thermal variation of viscosity and of electrolytic re- 
sistance ; by Cart Barus.—Experiments made on the effect of 
temperature (0) on the viscosity (77) of a very viscous substance 
like marine glue showed that log 7, g = log 7,,- B4@ very fully 


reproduced the results. The subscripts give the quantities con- 
stant and variable; p denotes pressure, and 6 is constant. For 
napierian logarithms, absolute measure, °C., and marine glue, 
oy = 10” and B=-379. In other words the rate at which vis- 
cosity decreases with temperature at 6°, is proportional to the 
viscosity at 6°. 

Experiments made on the effect of temperature on the electro- 
lytic resistance, 7, of a silicate (diabase) within 1500° C., showed 
that log (a+r) = log (a+6r,) — 6, very fully reproduced the 
results. Here a and 6 are constant and @ merely reflects the 
observational errors. For diabase, megohms and °C., a = ‘05, 
b = -009, r, =318X10°, napierian logarithms being taken. If @ 
be eliminated, =-010. In any case, however, the rate at which 
electrolytic resistance decreases with temperature, at the tem- 
perature 6°, is proportional to the resistance at 6°. Hence viscosity 
and electrolytic resistance conform with the same law, and I infer 
that a common kinetic principle underlies both. This may be 
stated thus : The rate at which cither configurational or molecular 
instability increases at the temperature 6, is proportional to the 
instabilities present in the given volume at that temperature— 
supposing that the number of unstable configurations, or of un- 
stable molecules, respectively, is at all times small relative to the 
total number of configurations or molecules. (Cf. this Journal, 
xlii, p. 135, § 12, 1892.) The thermoelectric equivalent, de = 
A ¢d 6,1 will soon develop.— Communicated by the Author. 

13. Outlines of Theoretical Chemistry, by LotHar Meyer, 
translated by P. Purtyres Bepson and W. Carieton WILLIAMs. 
With a preface by the author. 220 pp. 8vo. London and New 
York (Longmans, Green & Co.).—The name of the author and 


256 Scientific Intelligence. 


the character of his well known larger work upon Modern Theo- 
ries of Chemistry are sufficient euarantee of the excellence of 
this new volume. Although there are a number of admirable 
books at hand upon the ‘philosophy of modern chemistry, each 
one may be said to occupy a place and have a peculiar value of 
its own, and this is particularly true of this work by Professor 
Meyer. It gives a clear, well balanced discussion of the various 
topics embraced under the head of theoretical chemistry, and 
would be read with profit by students in this department of 
science. 

14. Theoretical Mechanics: A class book for the elementary 
stage of the Science and Art Department, by J. SPENCER. 
243 pp. 12mo. London, 1892 (Percival and Co.).—This little 
book, by an author who has had much experience in this line, 
fills well the place for which it is specially prepared. The prin- 
ciples are clearly stated and liberally illustrated by numerical 
examples. If the solutions by geometrical methods seem 
awkward, their use must be ascribed to the fact that the author 
is not at liberty to assume that his readers have a knowledge of 
trigonometry. 

15. Die Negativ-Retouche nach Kunst- und Naturg gesetzen. Mit 
besonderer Beriicksichtigung der Operation (Beleuchtung, Ent- 
wicklung, Exposition) und des photogr. Publikums. Ein Lehr- 
buch der kiinstlerischen Retouche fiir Berufsphotographen und 
Retoucheure von Hans Arnoxtp 480 pp. Vienna, Pest, Leipzig, 
1891 (A. Hartleben).—This is a readable volume in an interest- 
ing branch of photography, discussing the several topics with 
much fullness; the scope of the work is given in the title quoted 
above in full. 


Il GkroLtocy AND MINERALOGY. 


1. Upraised Coral Islands off New Guinea.—In the course 
of a journey through British New Guinea, in January last, the 
indefatigable Administrator, Sir William Macgregor, examined 
and described several remarkable islands, which he shows to be 
almost certainly ancient atolls that have ‘been elevated by steady 
horizontal uplift. The island generally known as Kitava (but 
called Nowau by the natives) has an area of about five or six 
square miles. It appears to be surrounded by a fringing reef. 
Nearly all round the island there is a low and slightly sloping 
margin covered with trees, and about a quarter of a mile wide. 
This terminates inland in a steep coral wall, which rises abruptly 
to the height of 300 or 400 feet, and is covered with forest. ° 
Shells in the coral point to a comparatively recent upheaval. 
From the crest of this wall the land dips gently to a plateau 
from 50 to 100 feet lower, which occupies the center of the 
island. The plateau is undulating, has a rich chocolate soil, and 
being protected from wind by the raised rim, whilst subject. to a 
copious rainfall, it is very fertile. All the people live in the 


Geology and Mineralogy. 257 


hollow, so that from the sea the island seems to be uninhabited. 
The central hollow is drained by filtration through the cracked 
and porous coral rock. Kwaiawata Island, which is from one 
and a half to two miles in diameter, showed precisely the same 
form and structure, and in Gawa Island there is a still more 
perfect instance of a raised atoll. The coral wall in the last 
instance rises so abruptly to the height of about 400 feet that 
part of it has to be climbed by ladders, and the plateau repre- 
senting the old lagoon is nearly 100 feet below the level of the 
edge. Iwa, another adjacent island about a mile in diameter is 
of the same kind, only the gently sloping border has been worn 

away, and the coral cliff meets the sea nearly all round.— Proce. 
Roy. Geograph. Soc., June, 1892. 

2. The Origin of Igneous Rocks.—Mr. J. P. Ippines, in a 
paper read before the Philosophical Society of Washington in 
June last. (Bull., vol. xii), has made a very important contribution 
to science on the Origin of Igneous Rocks. After mentioning at 
length the opinions that have been presented on the subject, he 
considers the intimate relations of the various igneous rocks in 
mineralogical constitution, and especially in chemical composi- 
tion, illustrating the subject with a large array of facts and 
tables of analyses. Further, the associations or groupings of the 
different kinds of rocks in various regions of eruption: and the 
order of succession in origin or outflow in each region are 
reviewed. After a careful and judicious survey of these subjects 
in their various relations, the author presents the following con- 
clusions. 

The differences in kinds of igneous rocks are not due to the 
existence of two or more subterranean zones of unlike magmas, 
or of zones of unlike rock-material which under physical changes 
might become such magmas; but they arise from the local differ- 
entiation of a common magma; and the series, in any region of 
eruption, usually commences with a kind having the mean com- 
position of the series and ends with rocks of one or both 
extremes. Mr. Iddings remarks that this law, while it has its 
exceptions, holds for all the localities that he had personally 
studied, and for the order of eruption described by Prof. Judd 
for the lavas of the Lipari Island, “ which began with rocks of 
intermediate composition and has reached the stage where rhyo- 
lite and basalt are being thrown out.” Other conclusions are: 
that the variation in the composition of the rocks of a series of 
eruptions at any volcanic center is the result of the chemical 
differentiation of a magma of mean or intermediate composition ; 
that molten magmas are essentially solutions, as put forth by 
Bunsen—a point illustrated in the experiments by Barus and 
Iddings described on a preceding page; that in each case those 
portions of the magma which were the later to crystallize may 
be considered as having been a solvent for the other portions—a 
solvent not for the silicates necessarily but for their constituents; 
that the differentiation in any case is due chiefly to differences in 


AM. JOUR. Sct.—TutrRD Series, Vou. XLIV, No. 261.—SrPTEMBER, 1892 
17 


258 Scientific [ntelligence. 


temperature, the temperature varying with the condition of the 
source of the magma, its relations to the enclosing material, and 
other causes. 

The views presented by Mr. Iddings tend to simplify greatly 
the subject of rocks, as the author states in his concluding para- 
graph: “The confusion which has overtaken the classification of 
igneous rocks and the burden which is being heaped up by the 
present tendency to multiply its terminology by creating names 
for each modification of rock, will find their remedy in a more 
logical conception of the true nature of the differences and rela- 
tions of rocks.” 

3. Bulletin of the Philosophical Society of Washington, vol. 
xi, 618 pp., 8vo. Washington, 1892.—This volume, covering 
the years 1888 to 1891, inclusive, contains valuable papers by 
Prof. Langley, Capt. C. EK. Dutton, J. P. Iddings, E. D. Preston, 
F. W. Clarke, J. R. Eastman, Everett Hayden, W. J. McGee, 
G. H. Eldridge, Whitman Cross, and H. W. Turner. 

Captain Dutton’s paper “On the greater problems of Physical 
Geography,” relates to the earth’s form, changes of level, and 
mountain-making. In it he proposes (on p. 53), the term zsostasy 
for “ the condition of equilibrium of figure to which gravitation 
tends to reduce a planetary body irrespective of whether it be 
homogeneous or not,” and discusses “How nearly does the 
earth’s figure approach to isostasy ?” He speaks of the theory 
he presents as a modified form of the theory of Herschel and 
Babbage. The effects of denudation and transportation in deter- 
mining movement of material under the law of isostasy are also 
considered, and concluded to be such along coasts as would 
shove the material of the sea bottoms landward. Mr. Dutton 
argues also that they might produce systematic plications like 
those of the Appalachians, stating as an “important fact that 
these systematic flexures were mainly formed at the times the 
sediments were deposited,” and that ‘‘ this isa fact of geologic 
observation.” Whose “observation” is not mentioned. 

Mr. Dutton remarks that isostasy offers no explanation of 
the great permanent changes of level; that its very idea means 
the conservation of profiles against lowering by denudation on 
the land and by deposition on the sea-bottom ; that the cause of 
permanent changes in the profiles of the land and sea-bottom, or 
the real nature of the uplifting force, is an independent one, and 
to him “an entire mystery.” ‘ But,” he adds, “I think we may 
discern one of its attributes, and that is a gradual expansion, or 
a diminution of density, of the subterranean magmas. If the 
isostatic force is operative at all, this expansion is a vigorous con- 
sequence; for whenever a rise of the land has taken place one of 
two things has happened: the region affected has either gained 
an accession of mass, or a mere increase of volume without in- 
crease of mass.” The former supposes a raising of the plateau 
against its own rigidity and its statical weight; the latter no 
overcoming of resistance; and hence, Mr. Dutton infers that the 


Geology and Mineralogy. 259 


cause of elevation, whatever it may be, involves the expansion of 
the underlying magmas and the cause of depression, their shrink- 
age. 

oe Siliceous bed consisting of Diatoms, Radiolarians and 
Sponge-spicules, in the Hocene of New Zealand.—This siliceous 
bed of organisms, occurring on the east coast of the South Island 
of New Zealand at Oamaru, whose Sponge-spicules are described 
by Dr. G. J. Hinde and W. M. Holmes (in the J. Linn. Soc., 
1892), is regarded as probably a deep-sea deposit, ‘comparable 
with the Diatom ooze which now forms a belt of varying width 
surrounding the South Polar Regions, between the Antarctic 
Circle and the 40th parallel,” at “a depth of 600 to 1975 fathoms, 
and an average of 1477 fathoms. A bluish siliceous deposit now 
found off the same east coast at depths of 700 to 1100 fathoms 
is very different. in consisting chiefly of material from the land 
with few siliceous organisms. 

5. A Preliminary Catalogue of the systematic Collections in 
Economic Geology and Metallurgy in the U. S. National Mu- 
seum, by Frepreric P. Dewey. 256 pp. 8vo. Washington, 
1891 (Bulletin of the United States National Museum, No. 42).— 
This bulletin gives not only a full description of the National 
Museum collections, but also a valuable account of mining and 
metallurgical processes in the different parts of the country, 
illustrated by many admirable plates. 

6. The Paleontology of the Cretaceous formation on Staten 
Island; by Arraur Houck. Reprint from Trans. N. Y. 
Acad. Sci., vol. xi, 1892.—Dr. Hollick gives in this paper a brief 
summary of the various discoveries that have been made by him- 
self and others of animal and vegetable remains on Staten Island. 
They consist altogether of eight species of mollusks and a dozen 
or more of plants, many of them in a bad state of preservation. 
They were found at Kreischerville, Tottenville, Eltingville, 
Prince’s Bay, Arrochar and Clifton, in more or less ferruginous 
and concretionary matter underneath the bowlder drift or some- 
what mingled with it and bearing evidence of considerable dis- 
turbance. Only at Kreischerville are the Cretaceous clays found 
in place. The shells are of marine Cretaceous type and the 
plants are characteristic forms of the Amboy clays of New 
Jersey across the Kill and the Raritan, most of which, however, 
were originally described by Heer from the Cretaceous of Green- 
land, or by Lesquereux from the Dakota formation. The plants 
were all found at Tottenville and Prince’s Bay, and Dr. Hollick 
shows that their occurrence can be accounted for on the theory 
of glacial transportation from the well-known plant-beds of the 
Woodbridge district, but he thinks the marine shells of Arro- 
char, sheltered on the west by the Archean ridge, do not admit 
of this explanation and must be regarded as in place. The 
paper is illustrated by four plates, three of which are devoted to 
the plants. The figures are remarkably clear and instructive. 

L. F. W. 


260 Scientific Intelligence. 


7. Untersuchungen tiber fossile Holzer Schwedens ; von H. 
Conwentz. Kongl. svenska Vetenskaps-Akademiens. Bandet 
24, No. 13.—The vegetable remains described in this important 
memoir all come from the southern extremity of Sweden, some- 
times called Scania, in which so many horizons are exposed that 
yleld fossil plants, especially the Rhetic and the Pleistocene. 
Nilsson, as long ago as 1831, proved that there was a Tertiary 
plant bed at Kipinge, and Onn we have evidence of an Upper 
Cretaceous (Senonian) deposit, called the Holma sandstone, 
which contains coniferous remains consisting of silicified trunks 
in place and also lesser twigs and even well-preserved pine 
cones. Most of these belong to two species, both of which are 
regarded as new to science, which Dr. Conwentz here fully 
describes and illustrates in his thorough manner, both in their 
external characters and their internal structure, and names 
respectively, Pinus Nathorsti and Cedroxylon Ryedalense. The 
Holma Sandstone occurs on both sides of the Ryssberge north of 
the 56th parallel of north latitude. 

Besides these remains in place the present memoir also 
describes a large amount of drift wood (Geschiebehdlzer) from 
the extreme southern peninsula, much of which had long lain in 
the museums at Stockholm and elsewhere awaiting identification. 
Most of these proved to be coniferous, but wholly unlike the 
Holma Sandstone flora, having the Sequoia type of structure 
which is referred to Cupressinoxylon, or if roots, to Rhizocupres- 
sinoxylon. One piece, however, turned out to “be a palm stem 
and was intrusted to Dr. Stenzel who is so great an authority on 
such forms. He describes it as Palmacites jiligranum, a new 
species of fossil palm. 

As regards the original source of those blocks of silicified 
wood, their systematic character is sufficient proof that they can- 
not be in place in the comparatively modern drift (Diluvian) in 
which they chietly occur. They differ too widely from the 
forms found in the Holma Sandstone to make it at all probable 
that they belong to that age. The author concludes that they 
were originally “derived from a formerly wide-spread Tertiary 
formation, the softer parts of which have been long since eroded 
away leaving only these heavy undestructible blocks of silicified 
wood which now lie buried under the superficial deposits. 

L. F. W. 

8. On Penfieldite, a new species; by KF. A. Genta. (Com- 
municated by the author.) —While examining a lot of minerals, 
formed by the action of sea water on ancient slags which Mr. 
Geo. L. English collected at Laurion, Greece, I noticed a very few 
hexagonal crystals which proved to be a new species, for which I 
propose the name: Penfieldite, in honor to Prof. Sam’] L. Penfield 
the indefatigable worker in mineralogy and crystallography. 

Hexagonal; generally in prisms with basal plane; the first 
pyramid is indicated by striation of the prismatic planes; a second 
obtuse pyramid appears on some of the crystals in small triangu- 


Geology and Mineralogy. 261 


lar planes. Some of the crystals are tapering at the ends and the 
basal plane is thus obliterated. The crystals with basal plane 
are generally dull, being coated with an opaque film, suggesting 
incipient alteration. Cleavage indistinct, basal. The tapering 
erystals from 0°5-1™™ thick and up to 5™™" long, the opaque from 
0-5-2" thick and 2-3™™ long. Color white; luster vitreous, in- 
clining to greasy. B.B. in a closed tube, gives no water, decrepi- 
tates and gives an abundance of sublimed lead chloride, soluble in 
water, leaving a yellowish white oxychloride. Easily soluble in 
dilute nitric acid. 


Composition = PbO. 2PbCl,. 


The analyses gave : 


ile 2. 

Tapering crystals. Opaque crystals. Calculated 
Ole 18°55 17°94 18°21 
bi 78°25 lost. 79°73 
o— wi as as 2°06 

100°00 


Associated with the Penfieldite is a mineral in long (up to 10™") 
silky needles, which largely volatilizes on heating, and may be 
another form of Penfieldite, or a new mineral; the other associ- 
ates are anglesite and small quantities of laurionite. 

Philadelphia, July 26th, 1892. 

9. Brief notices of some recently described minerals.—M asRitE 
is a fibrous kind of alum found in Upper Egypt and described by H. 
Droop Ricumonp and Hussein Orr. It contains a small amount 
of cobalt and, as believed by the authors, a minute quantity of a 
new element for which the name masriwm is proposed, after the 
Arabic name for Egypt. Assuming that masrium is a bivalent 
element, its atomic weight is calculated as 228, and it is regarded 
as belonging in the beryllium-calcium group in which group there 
is a place in the periodic system for an element with an atomic 
weight of 225. The analysis of masrite gave: 

SO; ANSOgy e203) 9 2 MnO; CoO heO) 9 HL0>%) Insol: 
DOO meLOO 2. Oom On20 m2 OOn) L026 4:23). /4 0935 70 2:610 = 9100 

* X= Masrium oxide.—Proceedings Chem. Soc., April 21, 1892; 
Nature, May 26. 

Basiture is a hydrous manganese antimonate described by 
icELstROM from the Sjé mine, Grythytte parish, Sweden. It 
occurs in steel-blue bladed forms with metallic luster, which it 
loses upon exposure; it is not magnetic. An analysis gave: 


Sb20; Mn.0; Fe.03 H.O 
13°09 70°01 Or: 15:00 = 100°01 


For this the formula 11Mn,0,.Sb,O,.21H,O is calculated.— 
Geol For. Forh., vol. xiv, 307, 1892. 


262 Scientific [ntelligence. 


SJOGRUVFITE is a manganese arsenate, also described by IeEL- 
sTROM, from the same locality. It occurs in crystalline granules 
or seams in jacobsite. The color is light yellow, resembling 
some garnet, but its hardness is less. An analysis gave: 

AsO; Fe.0s MnO CaO PbO H.O 

49°46 11°29 27°26 3°61 174 68h =) 1007 


It is not far from other manganese arsenates actually described, 
and it needs further examination to prove that it is a distinet 
mineral.— did. 


Ill. MisceLLANEous SCIENTIFIC INTELLIGENCE. 


1. Transactions of the Wisconsin Academy of Sciences, Arts 
and Letters, vol. viii, 1888-1891, 448 pp. 8vo. Madison, Wisce., 
1892.—This volume contains besides other papers, the following 
on Physical, Geological, and Natural Science: Chamberlin, 
Additional evidences bearing on the Interval between the Glacial 
Epochs; W. M. Wheeler, On the Appendages of the first abdom- 
inal segment of embryo Tnseets (54 pages with 3 plates); C. D. 
Marsh, on the deep-water Crustacea of Green Lake; H. ‘RB. 
Loomis, on the effect of changes of temperature on the distribu- 
tion of magnetism; E. Kremers, on the Limonene group of 
Terpenes (63 pp.); E. A. Birge, List of Crustacea Cladocera 
from Madison, Wisconsin, with a plate; besides papers by C. R. 
Van Hise and F. Leverett that have appeared in this Journal. 

2. A Dictionary of Altitudes in the United States, Second 
Edition. Compiled by Henry Gannett, Chief Topographer. 
393 pp. 8vo. Washington, 1891 (Bulletin No. 76, U.S. Geol. 
Survey).—In the new edition of this useful work considerable 
additional matter has been added, and the arrangement is changed, 
the places being in alphabetical order throughout instead of being 
grouped under the several States. 

Through Mr. Gannett the Survey has recently issued an excel- 
lent colored contour: -map of the United States. 


Journal of American Ethnology and Areheology, edited by J. Walter Fewkes. 
Voi. ii, 194 pp. with several illustrations. This volume contains papers by the 
editor on a few Summer Ceremonials of the Tusayan Pueblos; Natal ceremonies 
of the Hopi Indians; Report on the present condition of a ruin in Arizona 
called Casa Grande. 

The Humming Birds, by Robert Ridgeway. This work of 150 pages, with 46 
plates, is from the Report of the National Museum for 1890, pp. 253-383. 

Silk Dyeing, Printing and Finishing, by G. H. Hurst, F.C.8., 226 pp. 12mo, 
with 11 plates of samples of colored silks. London, 1892.--George Bell & Sons, 
London and New York. 

Principles of the Algebra of Physics, by A. Macfarlane, Fellow of the Roy. 
Soc. of Edinburgh, Prof. Phys. Univ. Texas. 117 pp. 8vo. Salem, Mass.—Salem 
Press Publishing and Printing Co. 

The Optical Indicatrix and the Transmission of Light in Crystals, by L. 
Fletcher, M.A., F.R.S. 112 pp. 8vo., with 21 wood cuts. London, 1892. -—Henry 
Frowde ; Macmillan & Co., New York. a 

Annuaire Géologique Universel : Revue de Géologio et Paléontologie, by Dr. 
L. Carez et H. Douvillé, Année 1890, Tome vii, 42 Fascicule. pp. 817 to 1168. 
Paris.—Comptoir Géol. de Paris. 


A. E. FOOTE, M.D., 


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'XXXII.—Note on the change of electric ‘cond uouiyiey ob- 


ew iis —HEstimation and Dehydration of Silver Oxide; ” 


> M. RaowL Picret, 253.—New method of determining the specific inductive 


- Miscellaneous Scientific Intellig gence—Transactions of the Wisconsin eae i 


Oo 


Anr. XXV; Be Gulf of Maxise as a Measure of ‘Teostee ce 
by Wid. a iCG mas eee ne ae ee 
XXVI.—Persistence of Vision; by E. 8S. Ferry .-..------ 192 
XXVII.—Kilauea in April, 1892; by_8. -E. -Bisnior =e 207 | 
XXVIII.—The Devonian Sycteu of Eastern Pennsylvania ; 
by ©. DEI ROSS ER 20s 30h See emiere: 
ATK. —Czsium-Mercuric Halides; by H. i WELLS 2. 221 
XXX.—Relations of the Laurentian and Huronian on the | 
North Side of Lake Huron; by-A. E. Bartow ..-__- é 236 | 


XXXI—Some Convenient Forms of Laboratory Appar tus pee 
by Ee Al GOOCH 226 tae. 3s SEs pi a oe eee - 239 ; 


served in rock magmas of different composition on pass- 
ing from. liquid to solid; by Carut Barus and J. P. 
Ipprves. ee ee epee a — 242 


by M. CaREYy oe igs SSeS eee EE 2 ke = gree 2S 


SCIENTI" “9 INTELLIGENCE. 


Chenustry and Physics—Phenomena of Codl-dust Explosions, THORPE, 250.— 
Certain new forms of Carbon, Luzi, 251.—Quinite, the simplest’ Sugar of the 
Inosite group, BaryER: Relation between the Color of Compounds and their 
Chemical Constitution, ScHUTzE, 252.—Free Hydroxylamine, LOBRY DE BRUYNE: 
Physical and chemical phenomena under the influence of very low temperatures, 


capacity of a dielectric, F. T. TRouron and W. HE. Linty: Action of the Hlecitric 
discharge on Gases and Vapors, C. LUDEKING: Ratio between the Electromagtie 
-and Electrostatic Units, M. H. ABrawAm: Influence of Electrification on Cloud _ | 
_ Condensation, J. AITKEN, 254.—Thermal variation of viscosity and of electrolytic 
resistance, C. Barts: Outlines of Theoretical Chemistry, L Mpyzr, 255.— | 
Theoretical Mechanics, J. SpENcER: Negativ-Retouche nach Kunst- und Nanos 
gesetzen, HANS ARNOLD, 256. : 


Geology and Miner Hoes Genie Coral Islands off New Canes 256. ope of 
Igneous Rocks, J. P. Ipprnes, 257.—Bulletin of the Philosophical Society of 
Washington, Te ou Isostacy, 258.—Siliceous bed consisting of Diatoms, 
Radiolarians and Sponge- -spicules in New Zealand: Preliminary Catalozue of the © 
systematic Collections in- Economic Geology and Metallurgy in the Des 
National Museum, F. P. Dewey: Paleontology of the Cretaceous formation OI 
Staten Island, A. ES 259. —Untersuchungen uber fossile Holzer Schwe- 


notices act some reoenly described minerals, 261. 


Sciences, Arts and Letters: Dictionary of Altitudes in the United States, 
GANNETT, 262. PCE AAS. 3 : Rite Gre 


Chas. V. VV aicott, 
' U.S. Geol. Survey. 


i 20s AMERICAN 
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Art. XXXIV.—On a Color System; by O. N. Roop, 
Professor of Physics in Columbia College. 


[Read before the National Academy of Sciences, Nov. 12th, 1891.] 


Ir is possible to combine by rotation a circular disc of card- 
board painted with vermilion, with a similar dise covered with 
a bluish-green pigment exactly complementary to the red, and 
to ascertain whether by mixture a gray is produced when the 
two colored areas are equal. If such should be the ease, in a 
certain sense we could say that these two colors were equal, in 
spite of differences of luminosity or amounts of white light 
mingled with them. If it were found that to make the mixture 
neutral, more or less red were required, we could assign to the 
vermilion disc a coefficient of 1, and to the blue-green disc its 
proper coefficient whatever that might be. Supposing for the 
sake of simplicity that the coefficient of the blue-green disc 
was also equal to unity, we then could mark the positions of 

the two colors at the extremities of a straight line and at its 
middle point locate white (gray), and we would then have a 
line containing, so to speak, all possible mixtures of these two 
colors, and by simple processes could indicate on it the posi- 
tions, and consequently coeflicients, of any red or blue-green 
surfaces having hues of the same character; for example, a red 
surface reflecting half the amount of red light of our standard 
disc, would be located half way between the positions of the 
standard red and of white, while another red disc might even 
find its position on the same line outside of our standard. In 
all these cases the vermilion disc would be the material stan- 


Am. Jour. Sc1.—Tsirp Series, Vou. XLIV, No. 262.—OctToBEr, 1892. 
18 


264 O. VN. Rood—Color System. 


dard to which a great number of reds and blue-greens, more or 
less pale or intense, could be quantitatively referred. But it 
might be possible to go farther, and to be able to say that our 
standard vermilion dise reflected the same amount of red light 
that is furnished by white card-board under the same illumina- 
tion, or that at all events it reflected a known fractional part 
of it, All the colors just spoken of would then be virtually 
referred to white card-board, or to some other white reflecting 
surface as might be determined on, and the standard red dise 
could at will be reproduced at any time or in any part of the 
world. To the reproduction of standard red discs I have not 
devoted much time, as before they can be made valuable a 
much more difficult problem must be solved. 

For if we undertake to go farther than the proceeding just 
indicated, and build up a whole system of colors we are imme- 
diately confronted by the fact that we are quite unable to leave 
our line; or for example, to express the amount of orange 
colored ight or of green light reflected by other discs in the 
same terms, or to bring them all into one system. As Helm- 
holtz has remarked,* masses of colored light which when 
mixed with their complements furnish in pairs the same white, 
may be said to belong to the same system and may be located 
at equal distances from the same center. A set of ideal dises 
which when combined pair-wise all furnished the same white, 
would in this system find their positions on the circumference 
of a circle with white at the center. But it is not practicable 
to experiment directly in this way, as it is nearly impossible to 
measure directly the amounts of white light mingled with the 
colored in the case of painted surfaces. 

I have employed a different proceeding and built up with it 
a reproducible system, which, as far as I can ascertain, is the 
one above indicated. Let us suppose that the positions of our 
standard red and its complement have been laid down at the 
extremities of a line with white at its center: we then combine 
with the red disc a green which is a little too blue to be 
strictly complementary, and obtain the best neutralization, the 
gray furnished having the least perceptible color, and we will 
suppose that this takes place when the areas of the two colored 
surfaces on the composite disc are equal; we shall then know 
that the new color also belongs on the circle not far from the 
complement of vermilion. One step has thus been taken, 
we have been abie to leave our first line of mixtures. We can 
then with ease and certainty locate the complement of this new 
hue, which will be a little more orange than the vermilion; or 
better still, we may combine the new color with one that is 


* Handbuch der Physiologischen Optik, p. 287. 


O. NV. Rood—Color System. 265 


still more refrangible than its true complement, and locate a 
dise which is still more orange, advancing thus more rapidly 
in the work. In the same way this orange-red dise will enable 
us to add a still bluer green, until in this way all the colors of 
the chromatic circle have been provided for and all our colored 
discs have received coefficents, for of course it will rarely hap- 
. pen that the actual positions of the colored discs fall on the 
circle, mostly they will be well inside of it. The first part of 
the work then consists in assigning coefticients to a series of 
painted discs which are arranged so as to have only small pro- 
gressive differences of color. 


Mode of experimenting.—To compare together colors which 
are not strictly complementary a number of precautions must 
be taken. In the first place, the pairs of dises employed should 
always have as nearly as practicable about the same coefticients ; 
consequently the selection of the colored papers offers very 
considerable difficulty, and in the majority of cases it has been 
necessary for me to prepare the paper specially for each case as 
it arose. Of course it is desirable to use papers with as high 
coefficients as possible, but cases occur where one is compelled 
to use lower coefficients (blues and cyan blues) and in these it 
is always necessary, so to speak, to take a fresh start, and to 
descend to the lower coefficient by a line passing through the 
center of the circle and not outside of it, that is by reaching 
the other side of the circle by the aid of a complementary dise 
with a lower coefficient. 

It is absolutely necessary that the eyes should be thoroughly 
rested after each individual observation, and they should be 
protected from side lights by a hood. Only the central por- 
tion of the retina should be used; that is, the colors should be 
-observed through a small aperture in blackened card-board 
held at arms length. It is an advantage and a saving of time, 
to protect the eyes with quite dark neutral spectacles while 
engaged in the manipulations not involving observation of the 
colors. 

As a source of illumination, sunlight falling on a stretched 

sheet of bleached cotton cloth was employed, and only the 
hours near noon were utilized. The frame with the white 
cloth was outside of the window, inclined at a suitable angle, 
and consequently was behind the observer as well as placed 
symmetrically to the colored dises. Extraneous light from 
buildings and blue sky was screened off and the room suitably 
darkened. If light from a uniformly overcast sky is employed 
a different set of coefficients will be obtained, and there is 
reason to believe that they vary somewhat with the nature of 
the sky on such days. 


266 O, N. Rood— Color System. 


in some observations it was found advisable, for the sake of 
using high coefticients, to employ paper which was slightly 
fugitive, but by properly arranging the process the evil effects 
of this were obviated. 

The coefficients of two strictly complementary discs are as 
their distances from the center or from white, and this distance 
is of course measured along the two radii that make up the 
diameter, but in the method used by me for colors not strictly 
complementary, the cosine of a small angle is necessarily 
employed and treated as if it were a radius. The angles used 
however were quite small, from 1°°5 to 3°, and consequently 
the error in any individual case was insignificant, but it is 
cumulative and finally becomes comparable with those of obser- 
vation. After the uncorrected results have been plotted in a 
Newton’s diagram, the angular distances of the colors will be 
known, very nearly, and the small errors from this geometrical 
source can be corrected and a fresh diagram constructed. 

As above stated, it was not found advisable to employ angles 
larger than about 38°, since with larger angles the results were 
more uncertain, while with the angle above indicated the 
manipulation was hardly more difficult than in the case of truly 
complementary discs. 


Mode of ascertaining the most neutral mixture. 


Let us suppose that we wish to obtain the most neutral mix- 
ture that can be furnished by yellow and blue discs that are 
not complementary ; the best method of procedure according 
to my experience is the following: a pair of large blue and 
yellow dises are combined as shown in figure 1, and on the 
same axis comes a black and white dise destined to furnish the 
comparison grays, and again on this, smaller yellow and blue 
discs cut from the same papers. Of course these three com- 
pound dises can be varied independently of each other. We 

1. start now with an amount of yellow on the 
larger dise which is far too small for ap- 
proximate neutralization, and on the 
smaller dise with still much less yellow, and 
call the difference between the sectors the 
interval. This interval in any given case 
is always to be kept roughly constant, and 
the more nearly complementary the dises 
are, the smaller it may be made. There is 
however no gain whatever in trying unduly 
to diminish it, and such attempts tend only to defeat their 
object, it being far better and safer to have the interval too 
large than too small. The arrangement in figure 1 indicates 


O. N. Rood—Color System. 267 


about the first position for discs that have nearly the same 
coefficient, but are quite removed from being complementary. 
As soon as the compound dise is set in rotation it will be 
noticed that the mixture-tint furnished by the larger disc is the 
least colored of the two, and the amount of yellow in it is to 
be increased, the smaller disc following with the same interval, 
and this proceeding is to be pushed forward till the observer 
is unable to decide whether the larger or the smaller dise is 
the paler, the least colored. Both will differ sensibly from the 
pure gray mixture, and the two pale mixtures will differ from 
each other in hue, still after some practice the observer will 
learn to decide with promptitude that they differ about equally 
from gray. This is a much more certain and easy process 
when in general only a little color is present, than when the 
hues presented are at all decided, and this is the reason that 
in building up the system the advances were made by small 
steps. The first half of an observation being now made and 
the mean noted, the yellow element is made from the start to 
preponderate considerably, the interval is preserved, and with 
a reversed approach the best neutrality obtained. The two 
readings constitute one complete observation, and if the maxi- 
mum reliability is demanded, not more than five complete 
observations in any one case should be made on the same day, 
it being more profitable to devote the remaining time to other 
determinations. 

As an example of the results to be attained I give three 
sets of determinations for five discs with rather low coefficients, 
each number being the mean of only three complete observa- 
tions made on the same day : 


CBI eo tide at "585 ‘BT 585 
ViGGe Sip ieiege 815067 “480 486 
GBs iene bear 466 “449 ‘452 
VSG PUR ee wn 432 ‘421 428 
[BOS elena tel ead 394 384 398 


When it is remembered that in photometric observations 
involving light of the same color the error in any one observa- 
tion may easily be two per cent and more it will be seen that 
these results are satisfactory so far as uniformity goes. 


By the methods above indicated I obtained the coefficients 
of a series of slightly differing discs ranging in color from 
orange-yellow through red into purple, and on the other hand 
from a somewhat yellowish green through cyan-blue to blue. 
Then, instead of extending the process all around the circle, a 
Newton’s diagram was constructed using the standard ver- 
milion disc, the extreme green attained and the blue. The 


268 O. N. Rood—Color System. 


angular positions of these colors were not arbitrarily assumed, 
but determined from the mixture equation and the ascertained 
coefficients. With the aid of this triangle and color equations 
experimentally obtained, I plotted in the usual way the posi- 
tions of five of the dises used in the building up process, and 
calculated their coefticients with the following result : 


Direct coef. Calculated. 
(Cel in pat ees | he aa Bok ay 1119 1°109 
ORIG ee ake sees EDO 123 
Pe Oe PETAR S peat ae es 1°229 HOY 7 
GilGyh sss eee oro artene, “S67 "892 
Pare 5 5 hs Be fF 7( 1h “566 
COV Se Se “806 “795 


GY5, a greenish yellow, was quite beyond the limits of the 
triangle. 

This agreement shows that the zig-zag process employed by 
me is homogeneous with that ordinarily used in Newton’s 
diagram, and from this it follows that it is not necessary to 
determine by my method coefficients for a greater number of 
discs than will furnish a properly shaped triangle, and that the 
remainder of the work can be done by the older method. It 
may here be remarked that in obtaining the fundamental equa- 
tion for the construction of the diagram and those for locating 
the colors, it is necessary to exercise far more suspicious care 
than is the case in the direct determinations of the coefficients. 
Although a pure gray is always attainable, theoretically, yet it 
seldom is obtained quite to the satisfaction of the observer ; 
the best way is to employ on the same axis duplicate sets of 
dises separated by the comparison gray, to vary the manipula- 
tion and multiply the observations. The work having pro- 
gressed thus far it becomes possible to ascertain the coefficient 
of any colored surface and to assign it a position in the dia- 

rain. 

: It may be remarked that the angular positions assigned to 
colors by the method just described agree in their main fea- 
tures with those given by me in a diagram on page 250 of 
“ Modern Chromatics,” which is founded on contrast observa- 
tions, the main differences being in the angular positions 
assigned in the diagram to violet and blue-violet ; these would 
have to be moved about 15° to the right, i. e., nearer to the 
other blues to make them coincide with positions furnished by 
this system. 

I give here some of the coefficients obtained: the vermilion 
with a coefficient of 1 had only a moderate brilliancy, being 
made of English vermilion applied to card-board as a paste: 
since then I have found in the shops a red, supposed to be 
vermilion, with a coefficient as high as 1174. 


O. NV. Rood—Color System. 269 


Chromemyellowm(paste)ia2s5) ess sass se 846 
( On NEW eae ran tp EER re "933 

66 Pale ” 66 CGsss Tne Ia oaths Soares Orig 2) he 99] 
iMimeraldpeneenyynac t= = 225) sayy 1119 
Prussian blue (wash) ~---.-..-- Rel aay Aa "354 
66 66 SOS SN Se RNa) DePPaN PaGs hee et "3992 
Cobaltibluen(paste)y a. oe 4 ok Ss 562 
An titeial Wits blue (paste) 3.25 esse 2006 
Crimson laken(@wash) ee cess cee eats 1°23 


The system which is here proposed can be built up by 
experimenters and ought to be practically identical in all cases 
if made by normal eyes, provided the same standard vermilion 
is used, or the coefficient of it is known, or in general if the 
starting point is made from any disc of bright color the coefi- 
cient of which is known. As before stated it may be possible 
hereafter to refer the coefficient of the vermilion dise to white 
eard-board, which indeed has been done in the case of my own 
disc with some approximation to correctness. The system 
may then be considered a fairly reproducible one, but the 
question still remains as to its nature. The thought that in it 
we have one where complementary colors having a determined 
coefficient of unity furnish the same gray, naturally suggests 
itself and is rendered probable by the following considerations. 
The standard red and its true complement when mixed furnish 
a certain gray, and it is evident that other pairs situated at 
small angular distances from them, such as 10° on either side, 
will sensibly do the same. This furnishes two sectors of 20° 
on either side of white; but the coefficients of the colors 
situated within them are reproducible with the aid of the 
triangle, which would hardly be the case unless the colors 
situated at its angles obeyed the same law, viz: furnished the 
same white when mixed with their true complements; this 
again applies to the reversed triangle and the two provide for 
about two opposite quadrants of the circle, and what holds 
good of these ought, it would appear, to apply to the remain- 
ing quadrants. 

The question whether in this system, all the colors located 
on the circumference furnish by mixture the same white when 
treated in pairs, is quite difficult to answer by actual experi- 
ment, as in the case of most of the discs it is very hard to 
ascertain the relative amounts of colored and white light 
reflected, owing to the well known fact that in most cases por- 
tions of the colored light mix, and produce what amounts to 
an indeterminate amount of white light. Some attempts, with 
the aid of the spectroscope, of colored glasses and of gray 
discs were made to measure the actual amount of standard 


270. L. Whittle—Ottrelite-bearing Phase of the 


white (gray) furnished by the mixture of the pure fundamental 
red and its pure complement; a number was obtained ex- 
pressed in terms of the luminosity of white card-board, and 
the same operation was performed for complementary yellow- 
green and purple as well as for yellow and blue discs. With- 
out laying much stress on the results obtained, it can at least 
be said that they did not render improbable the idea that these 
pairs all furnished equal grays when united. To settle this 
problem experimentally would of course require a considerable 
amount of elaborate work, if indeed it is at present capable of 
such solution. 


I shall be glad to furnish without cost samples of colored 
paper with coefficients to those who are particularly interested 
in these matters. 


Art. XXX V.—An Ottreiite-bearing Phase of a Metamorphic 
Conglomerate in the Green Mountains ; by CHARLES LIvy 
WHITTLE. 


[Published with permission of G. K. Gilbert, Chief Geologist, U. 8. Geological 
Survey. ] 


THE geological position of the limestone and quartzite of 
the Rutland valley has lately been definitely determined, the 
limestone paleontologically and the quartzite stratigraphically.* 
Occurring next below the limestone the quartzite is the northern 
continuation of the Clarksburg-mountain quartzite in Massachu- 
setts in which Walcott has. found the Olenellus fauna charac- 
teristic of the Lower-Cambrian horizon. About one mile north 
of Rutland village, in Vermont, Dr. Wolff and Dr. Foerste were 
fortunate enough to find Lower-Cambrian fossils in a siliceous 
limestone that lies superjacent to the quartzite. Northeast of 
Rutland the quartzite is found associated with a sandy, phyllitic 
schist that belongs to a series of metamorphosed clastics having 
a vitreous quartzite or conglomerate at its base. This whole 
series, barring the Lower Cambrian quartzite and limestone, has 
been subjected to the most intense dynamic action. The se- 
quence of the different members of the series is in many regions 
hopelessly obliterated and confused by the mountain-building 
forces that have produced new structural planes and a new min- 
eral composition; and have additionally complicated the geo- 
logical order of succession by sharp folding, as a rule too much 


*On the Lower Cambrian Age of the Stockbridge Limestone. Bulletin Geol. 
Society of America, vol. ii, pp. 331-338. 


Metamorphie Conglomerate in the Green Mountains. 271 


involved for decipherment. These phenomena are particularly 
true of the conglomerate horizon and its many phases, and it is 
in this rock that I wish to describe some of the evidences and 
effects of metamorphism shown by the destruction of old 
elastic minerals and in the production of new ones. 

Occurrence of ottrelite schist.—One of the most conspicuous 
- phases of the conglomerate is due to the development of ottre- 
lite in great abundance so that it is not uncommon to find 
fully twenty-five per cent of the rock made up of this mineral. 
The ottrelite is commonly most abundantly developed where 
the rock has now a well-marked schistose character that is due 
either to an original fine-grained deposit, or is a result of the 
shearing and crushing action of dynamic forces. It is often 
found, however, occurring in the groundmass of the coarsest con- 
glomerate or along planes of shearing in a blue, hyaline quartzite. 
Still another phase is more nearly massive, fully forty per 
cent being ottrelite, the rock at first sight simulating in appear- 
ance some porphyritic hornblende dike. The rock is a very 
variable one, but, considered as a whole it forms one of the 
most important stratigraphical horizons found in the more 
crystalline areas of the Green Mountains. In lateral extension 
it has been traced with unimportant breaks all the way across 
the Green-mountain anticlinal axis, as mapped by Hitchcock,* 
from Mendon, Vt., to North Sherburne, Vt. In vertical exten- 
sion it has considerable thickness although accurate determina- 
tion is very difficult owing to the obliteration of planes of bedding 
in many instances and the complexity of the flexures; but itseems 
safe to assume athickness of several hundred feet, at least in sev- 
eral localities that have been most carefully studied, viz: a spur 
extending south from Mount Carmel, in the town of Chitten- 
den, and the east and west crest forming the southern portion 
of the mountain, somewhat inappropriately named ‘Old Aunt 
Sal,” in the town of Mendon. The phases studied thus far in 
the laboratory are from this latter locality and from the western 
part of the “Rabbit Ledge” just south of Mendon “ City.” 

Physical and microscopical characters.—In the hand speci- 
men the ottrelite of the most massive occurrence of the ottre- 
lite-bearing rock appears either as isolated areas generally with 
_ rudely circular outlines, or groups of these in a background of 
fine-grained, pinkish-brown to dark purple quartz, in places 
constituting nearly pure ottrelite. These areas possess an 
approximate common diameter of about three-sixteenths of an 
inch. In structure they are made up of tabular areas of 
radiating imbricated plates generally arranged in essentially 
one plane for any single area; but the positions of the 


* See fig. 4, Section VI, Hitchcock’s ‘‘ Green Mountain gneiss,” Geol. of Vt., vol. 
ii, 1861. 


272 C. L. Whittle— Ottrelite-bearing Phase of the 


different areas seem in the main to be accidental, although 
locally they may be arranged parallel, as shown by a tendency 
in the rocks to cleave into rude slabs,—a tendency augmented 
by thin folia of sericite. A well-marked spherocrystalline 
habit characterizes all the ottrelite areas; in some this radiated 
growth seems to be perfect. 

Microscopically the radiated structure is much more evident ; 
composite and fan-shaped areas, penetrating one another irregu- 
larly coexist with isolated prisms and beautiful spherocrystal- 
line aggregates yielding imperfect crosses in polarized light. 
Only sections cut parallel to the bundles of plates (basal sec- 
tions) show well the radiated structure ; all other sections show 
this character less and less, dependant upon the plane of the 
section until it is transverse when the mineral appears prismatic. 
The areas of the spherocrystals are not infrequently bounded 
by overlapping six-sided plates of which three are usually free; 
the others are intergrown and confounded in the central por- 
tion of the aggregate. 

The extreme mobility of the ottrelite-bearing solution is 
indicated by the manner the ottrelite needles have insinuated 
themselves into included feldspar grains along no visible lines 
of fissuring. 

As in all described occurrences of this mineral an abundance 
of inclusions exists. It is noticeable that while quartz and 
occasionally feldspar are included, sericite, which is the prin- 
cipal micaceous constituent of the rock, is seldom enclosed by 
the growing ottrelite, but may be wholly or in part the nucleus 
about which an aggregate formed. Such nuclei seem to have 
governed the growth of the ottrelite. There is a tendency as 
the mineral formed for the plates to orient themselves parallel 
to the sericite nucleus so that when sucha nucleus is surrounded 
by basal ottrelite it is apt to be basal also. By far the most 
abundant interpositions are a multitude of extremely minute 
black to brown dots and aggregates. These with a No. 7 
objective are resolved, in the main into rutile occurring in 
knee-shaped and heart-shaped twins but generally in rounded 
forms in which twinning is not distinguishable. In other 
cases the highest objectives are incapable of individualiz- 
ing the grains as is mentioned by Rénard in his ‘ Researches 
Sur la Composition et La Structure Des Phyllades Ar- 
dennes.”* In some erystals the rutile is grouped in reticu- 
lated lines conforming rather rudely to the planes of the two 
principal cleavages; but, as a rule grouped along irregular 
lines that traverse the ottrelite and the groundmass alike, and 
was arranged originally in structural lines, possibly depositional 


*Phyllade Ottrélitifére de Monthermée: Bulletin De Musée D’Hist. Nat. D 
Belgique, 3, 1884, 785, p. 252. 


Metamorphic Conglomerate in the Green Mountains. 2738 


that afterwards were built into the ottrelite with total disre- 
gard to any observed relationship, in the same manner that 
quartz and feldspar droplets were built into albites in another 
phase of this rock. Other inclusions are graphite (determined 
by deflagration) and little coffee-brown ilmenite plates (titan- 
eisenglimmer). A powerful current from an electromagnet 
applied to the rock powdered and run through a 120-mesh 
sieve failed to attract but little, so that magnetite and prob- 
ably ferrous oxide are absent. The usual test for titanium 
gave a positive reaction. 

As in biotite and chlorite, pleochroic zones about crystals of 
zircon are very common in the ottrelite and the characteristie¢ 
dependence of maximum pleochroism upon maximum pleo- 
ehroism of enclosing mineral is observable. While zircon 
usually occupies the centers of these zones, others occur, hay- 
ing no perceptible associated inclusion, but are circular areas of a 
brownish color, not resolvable with the highest power, that are 
probably rutile grains. 


Ottrelite schist showing formation of ottrelite at many different points. Hach 
small area is oriented with all the others, forming a large area having a general 
prismatic outline. The prism (A) has been developed transverse to the schistosity of 
the rock. The background (B) is largely gneissic quartz with some secondary feld- 
Spar. x 25. 

Although twinning with composition face parallel’to O is 
not uncommon in the ottrelite a large part of what seems to 
be twinning is seen to be due to overlapping plates. As the 
stage is revolved the wavy extinction caused by this may be 
observed,—the usual spherulitic structure. Examples of 
erystal growth set up in several places at the same time occur 


274 C. L. Whittle—Ottrelite-bearing Phase of the 


in the rock, where each part is controlled by every other, result- 
ing in an irregularly-outlined prism composed of many indi- 
viduals. ‘These parts are separated by areas of the groundmass 
and yet are all oriented together (see fig. 1). This phenomenon 
is unlike that of andalusite. which occurs so frequently grown 
into large individuals enwrapping all other minerals of the back- 
ground ; but isanother example of independent parallel growth 
analogous to that of quartz in pegmatite. Such growths are com- 
monly developed nearly at right angles to the layers of quartz 
and feldspar that make up the schistosity, and are usually freer 
from inclusions than the bundles. They occur between the 
main areas of ottrelite and may represent a second generation ; 
they were necessarily formed after the groundmass was con- 
verted to a mosaic by granulation. 

The same phenomenon is noticed in the rutile. Little yel- 
lowish-brown grains of this mineral developed in the inter- 
spaces of the minerals composing the background tend, 
although made up of separate and sometimes isolated grains, to 
orient themselves parallel to one another, forming groups hav- 
ing prismatic outlines. These groups are only sparingly 
developed, but when observed they are generally parallel to 
one another and to the schistosity of the rock and are restricted 
in their occurrence, like the ottrelite individuals just deseribed, 
to the most quartzose parts of the rock which they enclose in 
the same manner as the ottrelite. 

An interlamination of chlorite and ottrelite at first glance 
was mistaken for either the contemporaneous formation of 
these minerals or an infiltration of chlorite parallel to the 
basal cleavage of the ottrelite. Further investigation, how- 
ever, showed that the chlorite as often traversed the ottrelite 
irregularly in bifurcating veins and enclosed parts of it (see fig. 
2). A study of the nature of these veins convinced me that 
the chlorite is an alteration product of the ottrelite. The 
edges of the veins where they traverse the ottrelite transverse 
to the basal cleavage are jagged, the saw-like teeth projecting 
along the composition faces or basal cleavage. The chlorite in 
such cases is distinctly made up of little fibers which have 
arranged themselves parallel to one another and to one set of 
twinning lamelle. Lines of inclusions once continuous in the 
ottrelite now stop short against interlaminated areas of chlorite 
showing the evident secondary nature of the latter mineral. 

In other places the chlorite is developed along the basal cleav- 
age, leaves this and follows one of the prismatic cleavages and 
then again follows the basal, making one continuous line, produc- 
ing steps in much the same manner that garnet does when it 
undergoes this alteration. Cores of unaltered ottrelite remain 
in the chlorite and the pleochroic zones once in the parent are 


Metamorphic Conglomerate in the Green Mountains. 25 


seen again in the secondary mineral, while the relationship of 
maximum pleochroism of these zones to the greatest pleo- 
chroism of the chlorite is handed down as well. This metaso- 
matic phenomenon has not been observed in other phases of 
the ottrelite-bearing conglomerate thus far studied by me. 


KA Ay 
ear. oA 
qd FAA 

Alteration of ottrelite to chlorite. A, overlapping plates of ottrelite. 3B, bifur- 
cating vein of chlorite allomorphosed after ottrelite and including cores of unal- 
tered mineral. ©, quartz and feldspar mosaic. 


The background of the rock is composed about equally of 
quartz and feldspar as principal constituents. The feldspar is 
fresh and glassy, untwinned and is probably albite ; but it is 
hardly abundant enough in the ottrelite-bearing phases to 
make the rock a gneiss even in mineralogical composition ; 
and, structurally, a gneissic habit has been nowhere observed 
where ottrelite exists to any extent. Sericite is also abundant 
and occurs in minute prisms between the interlocking quartz 
grains and enclosed by the albite generally, and rarely by the 
ottrelite. It also encloses lines of rutile dots arranged parallel 
to its cleavage planes, and, next to the ottrelite it is the last- 
formed mineral. ! 

Associated with rutile in the groundmass are groups of stout 
and slender prisms and plates having a very high single and 
double refraction and a variable color from brownish-yellow to 
blue even in the same individual. These I identified as anatase 
and for verification I studied Diller’s sections described in his 
contribution on “ Anatas als Umwandlungsprodukt von Titanit 
im Biotitamphibolgranit der Troas.”* Unlike the anatase 


*N.J.B., 1, 1883, pp. 187-193. 


276 C. L. Whittle— Ottrelite-bearing Phase, ete. 


there described its occurrence in narrow prisms in this rock 
together with its multitude of rutile inclusions seem excep- 
tional. The stouter prisms ae vetamune faces of an octa- 
hedron and range in size from 3, to gi}, of a millimeter in 
length. As the stage is revolved the pleochroism seems only 
the intensification of the inherent color of the mineral: browns 
become browner and blues, bluer. The presence of rutile 
inclusions shows the anatase to have formed after that mineral 
and suggests the probability of its being a paramorphie product 
of the rutile inclusions. 

Rutile dots and prisms exist in multitudes enclosed by all 
other minerals of a secondary nature. They are so extremely 
minute that even in a very thin section they focus in six or 
more different planes. 

All traces of original clastic material in the rock have dis- 
appeared: feldspar detritus, if it once occurred, has been con- 
verted into a mosaic of quartz, sericite, biotite and probabiy 
albite, and the detrital quartz has been granulated. The 
existing feldspar is the characteristic untwinned glassy variety 
carrying quartz and sericite inclusions so common throughout 
this horizon, and was formed after the granulation of the rock, 
since granulation could not have taken place without straining or 
crushing it. Nearly all the quartzis sprinkled with rutile inclu- 
sions, but it is noticed the larger areas have less of them and 
may be cores that have escaped granulation. Their presence, 
however, in such abundance militates against the probability 
of any of the quartz being allothegenic: and indicates, rather, 
its secondary nature. In the same way quartz may enclose 
plates of micaceous ilmenite but does not enclose sericite, 
There is evidence of two periods of dynamic action indi- 
cated by a faint wavy extinction in the feldspar, in some 
instances and by the bending and breaking of ottrelite prisms. 

We have then in this rock three titanium- bearing minerals 
(ilmenite, rutile and anatase) ottrelite, chlorite, feldspar and 
quartz. What is their genetic order of development? This is 
a difficult question to answer without more data and is particu- 
larly difficult in the cases of the ottrelite and rutile. The 
relative position of the former mineral can be determined 
easily, but the source of the solution introducing it is not easily 
discovered. Ottrelite was formed after the rock had undergone 
metasomatic and dynamic changes that converted its clastic 
feldspar to its resulting minerals, after its detrital quartz was 
sugared and the rock had become a stable aggregation of 
minerals under the conditions of environment then existing. 
This environment changing, owing to one or more of the many 
factors affecting the character of a rock mass, ottrelite was 
introduced probably and seemingly necessarily from some ex- 


E. L. Nichols—Age-coating in Incandescent Lamps. 277 


traneous source. The environment of the rock wnderwent a 
third change and this was probably an elevation which strained 
the albites, fissured the ottrelite and subjected the rock to nor- 
mal surface weathering, during which the conversion of ottre- 
lite to chlorite, was initiated. Prior to the granulation of the 
clastic constituents the titanium in some combination must 

have existed in the rock, but the mineralogical nature of this 
‘combination is obscure. The most likely source of rutile is 
from some titanium-bearing iron oxide the presence of which 
has not been made out definitely except in the case of mica- 
ceous ilmenite, itself manifestly of a secondary nature, occur- 
ring as it does in a clastic rock, and which yields no evidence 
of alteration. Ordinary granular ilmenite, such as occurs so 
abundantly in phyllites, which is prone to decomposition, was 
most likely the comraon source for all three minerals carrying 
titanium, the rutile being an intermediate stage in the for- 
mation of anatase. The micaceous ilmenite was developed 
before the formation of the gneissic quartz, since the latter 
encloses it; the anatase probably forming after the quartz, as 
it occurs in the interstices between the quartz grains. 

If this be a correct interpretation, the order of crystallization 
of the existing minerals is essentially as follows: first, rutile and 
micaceous ilmenite followed by the formation of gneissic quartz 
enclosing them and coincidently the growth of sericite-enclos- 
ing rutile. The glassy feldspars were then formed enclosing 
all the previously formed minerals, and the anatase may have 
resulted as an alteration product of the rutile at about this stage 
in the rock’s history. Then the ottrelite began its growth, 
including all the other minerals in the rock and finally the 
initial alteration of this mineral to chlorite closes its history up 
to the present time. 

Cambridge, Mass., March, 1892. 


Art. XXXVI—The Age-coating in Incandescent Lamps ; 
by Epwarp L. NIcHOLs. 


[Experimental work by Messrs. B. E. Moore and C. J. Ling. ] 


[Contributions from the Physical Laboratory of Cornell University, No. 11.] 


WHEN an incandescent lamp is maintained at constant volt- 
age, it invariably falls off in candle-power. The diminution 
in brightness is attended by an increase in the amount of energy 
consumed per candle-power of light; this change being spe- 
cially marked in the earlier portion of the life of the lamp. 


278 #. L. Nichols 


Age-cvating in Incandescent Lamps. 


This phenomenon, which seems to take place in all incandes- 
cent lamps of the present day, was first studied exhaustively 
by Mr. W. H. Pierce, who read a paper entitled “ The Relation 
between the Initial and Average Efficiency of Incandescent 
Electric Lamps,” before the American Institute of Electrical 
Engineers, in 1889.* Mr. Pierce made a careful study of 
ninety-four lamps, including nearly all the types of glow-lamp 
then in use. He found no exception to the rule of progressive 
degeneration.+ 

These changes may be ascribed to at least three causes: loss 
of vacuum, increase of resistance, due to the disintegration of 
the filament, and finally, the deposition of the disintegrated 
carbon upon the inner surface of the lamp-bulb. It was the 
object of the experiments to be described in this paper, to make 
a study of this coating. We endeavored (1) to determine its 
character; that is to say, whether it is colorless, or is selective 
in the particular rays it absorbs; (2) to learn something about 
the rate and distribution of deposit; and (3) to determine 
how far the absorption of light by the coating is accountable 
for the diminution in the brilliancy of the lamp. 

For the determinations under the first head, we made use of 
a form of polarizing spectro-photometer which has been more 
than once described in the pages of this Journal.t The 
standards of light were incandescent lamps. These were main- 
tained at a candle-power considerably below the normal, that 
the changes taking place in them might be slow. Frequent 
comparisons of their spectra showed that the relative changes 
of brightness and quality of light were inappreciable. 

The first step in our investigation consisted in the measure- 
ment of the absorption spectra of the bulbs of certain unused 
lamps, which had been selected for study. These lamps were 
then brought to degrees of incandescence, previously agreed 
upon, and were maintained in that condition by means of the 
current from a storage battery carefully kept constant, until 
they showed coatings of sufficient density to admit of ready 
measurement. They were then taken out of circuit and the 
absorption spectra of the blackened bulbs were determined. 
These readings gave the amount of light of each wave-length 
absorbed, and by repetition, the rate of deposition during dif- 
ferent periods of the lamp’s existence. The entire set of pho- 
tometric observations were duplicated, but since the final results 


*Trans. Am. Inst. EH. E., vol. vi, p. 293. 

+ Since the above was written an extended investigation upon this subject has 
appeared. It entirely confirms the results obtained by Mr. Pierce. (See ‘A 
life and efficiency test of incandescent lamps” by Prof. B. F. Thomas and Messrs. 
Martin and Hassler), Trans. Am. Inst. EK. E., vol. ix, 1892. 

t This Journal, vol. xxxvi, p. 332; also Phil. Mag., V, xxxii, p. 404. 


E. L. Nichols—Age-coating in Incandescent Lamps. 279 


obtained by the two independent observers (Moore and Ling), 
were in agreement, only the mean of the two sets is given in 
the following tables. 

In order to ascertain precisely what part in the decadence of 
the lamp is attributable to the coating, it was necessary to keep 
careful watch of the continually shifting electrical and photo- 
metric conditions during its entire life ; and in order to main- 
tain in each lamp the precise conditions under which it had 
been determined that it should be burned, measurements of 
candle-power and voltage had to be made at short intervals, 
together with continual readjustments of the current. 

Fourteen lamps in all were selected for the investigation. 
These were of two widely different types, representing the two 
great classes, viz: lamps with untreated and with treated fila- 
ments. Of these, some were maintained at the voltage indica- 
ted by the maker, or at predetermined, constant voltages other 
than this. Others were kept at constant candle-power through- 
out their entire life, the current being increased whenever the 
decrease in brightness due to increasing age had become 
appreciable. 

From the data obtained in this way, the life curves of the 
various lamps were plotted, showing the variation in candle- 
power or voltage respectively, of resistance and of efficiency 
expressed in watts per candle, during its entire existence. 
Some of these curves have already been published.* As these 
results were quite in accordance with those obtained by Mr. 
Pierce, to which reference has already been made, it will be 
necessary to deal with them here enly in so far as they bear 
upon the question of the influence of the age-coating upon the 
efficiency of the lamp. 


ite 
Color of the coating.. 


Measurements upon all fourteen of the lamps which were 
subjected to the spectro-photometric tests, showed the color of 
the coatings upon lamp-bulbs containing treated and untreated 
carbons, respectively, to be practically identical in character. 
_ The color of the coatings obtained in lamps of either type, 
under widely diverse conditions (as for example, by maintain- 
ing a sixteen candle-power lamp at sixty-four candles through- 
out its life), was the same as that produced under normal con- 
ditions of service. ‘The color in question is very nearly neutral, 
the percentage of light transmitted being approximately the 
same for all parts of the visible spectrum. The effect of the 


*The Artificial Light of the Future: Electric Club Pamphlets, No. 24, New 
York, 1890; also Electrical World, 16, p. 387, Electrical Engineer, 10, p. 595. 


A. Jour. Sct.—Turrp Series, Vou. XLIV, No. 262.—OctToBER, 1892. 
19 


280 FE. L. Nichols—Age-coating in Incandescent Lamps. 


“ age-coating,” as the deposit which we are considering may be 
called, is therefore to dim the lamp, without appr eciably chang- 
ing the quality of its light. 

"The most complete set of observations obtained with lamps 
of untreated carbon are those referring to a lamp designated 
in our list as No. 2.* This lamp was maintained at normal 
voltage for over eight hundred hours. Frequent readings of 
eandle-power and current, during this time, afforded the means 
of tracing the progressive changes of light-giving power, 
efficiency and resistance. Measurements of the age-coating - 
were made after 100, 200, 400 and 800 hours of life, readings 
being taken in ten regions of the spectrum. The results are 
given in Table I, together with data indicating the condition 
of the lamp at the above mentioned periods of its life. These 
are taken froma set of sixty-seven readings of voltage and 
current, distributed over the entire life of the lamp at “nearly 
equal intervals. The variation in voltage during the entire 
eight hundred hours was never more than 0°3 volts above or 
below the initial value. 

TaBe I. 
Lamp No. 2 (untreated filament). 


Initial Conditions. 


Volts. Amperes. Ohms. Candle-power. Watts per candle. 
101°8 0-474 214°8 16°00 3°015 
Conditions after 100 hours. 
Volts. Amperes. Ohms. Candle-power. Watts per candle. 
101°9 07455 225°3 12°50 3697 
Light transmitted by the coating, after 100 hours. 
hs 7150 88°9 per cent Wo XN 92°2 per cent 
‘7138 90-2 “481 9258 
"635 91:8 “460 92°3 
658 91°5 443 92-4 
538 Hk) “429 92.4 
Conditions after 200 howrs. 
Volts. Amperes. Ohms.  Candle-power. Watts per candle. 
101°8 0°42] 225°9 10°8 4°50 
Light transmitted by the coating after 200 hours. 
Nese 0, 83°5 per cent N= 50M 86°4 per cent 
“713 84°5 “481 86°Y 
°635 85°6 °460 87°6 
"580 85°4 "443 87:9 
538 85°9 “429 854 


*This and other numbers used refer to the records of these experiments as 
given in full in the thesis of Messrs. Moore and Ling, a manuscript deposited in 
the library of Cornell University. (The Life and Duration of Incandescent 
Tamps; with special Reference to the Light absorbed by the Coating within the 
Bulb, by B. HE. Moore and C. J. Ling. 1890.) 


EF. L. Nichols—Age-coating in Incandescent Lamps. 281 


Conditions after 400 hours. 
Volts. Amperes. Ohms. Candle-power. Watts per candle. 
101°8 0°428 23077 9°67 4°510 
. Light transmitted by the coating after 400 hours. 
1/00 aae Oro pel cent NS AK OH/ 83°5 per cent 


VHS eg OOL9 481 83°6 
635 §2°3 ‘460 84:0 
580 82°0 443 84°3 
538 82°6 “429 82°1 
Conditions after 800 hours. 
Volts. Amperes. Ohms. Candle-power. Watts per candle. 


101°9 0°415 245°6 7°20 5°880 


Light transmitted by the coating after 800 hours. 
N= 7150 75°7 per cent j= S07 78°7 per cent 


‘713 75°9 481 T9°4 
635 78:0 ‘460 1959 
580. 78°6 443 80°5 
538 78:4 “429 77°3 


Another typical case was that of lamp No. 10, which was a 
lamp with a treated filament. It was maintained at a very 
different degree of incandescence, being a lamp of low efh- 
ciency, which when set at the voltage indicated by the manu- 
facturer, required an expenditure of 5°16 watts per candle. 
The age-coating of this lamp approached even more nearly to 
complete neutrality of shade than did most of those which we 
had occasion to measure. The results obtained at two hundred 
and nine hundred hours are given in Table II. 


Tasie IT. 
Lamp No. 10 (treated filament). 


Initial Conditions. 


Volts. Amperes. Ohms. Candle-power. Watts per candle. 
36-0 eel 30°63 8°2 5°16 
Conditions after 200 hours. 
Volts. Amperes. Ohms. Candle-power. Watts per candle. 
35°9 1°145 S27 eal ool 


Light transmitted by the coating after 200 hours. 
jG) 91-9 per cent Nb Oi 90-7 per cent 


‘713 90°4 481 90°4 
°635 89°5 460 90°7 
"380 90°5 443 90°5 


338 90°5 "429 90°4 


282 EE. L. Nichols—Aye-coating in Incandescent Lamps. 


Conditions after 908 hours. 


Volts. Amperes. Ohms. Candle-power. Watts per candle. 
36°14 114 31°70 (unknown)* 


Light transmitted by the coating after 908 hours. 
N= 15.0 86°6 per cent N= 50M 84°5 per cent 


7/118} 85:2 “481 85:0 
635 83° 460 85'5 
“580 83°6 443 86:0 
538 84:5 429 86:0 


The normal life of a lamp starting at 5 watts per candle, is 
many thousands of hours. Lamp No. 10 was prematurely 
broken at 908 hours, at which time the coating had reached a 
density corresponding to that of a 3 watt lamp (No. 2) after 
200 hours of life. A comparison of Tables I and II will show 
that while the coatings on these two lamp bulbs were uot 
quite neutral nor precisely identical in tint, that they both 
transmit light with much greater uniformity than do such 
materials, for example as optical glass, calcite, ete.+ 


iub 


The distribution of the age-coating within the bulb. 


The distribution of the age-coating was determined indi- 
rectly, as follows: Two of the lamps under examination, were 
measured for horizontal candle-power according to the “ Frank- 
lin Institute” method ;{ measurements being made in twelve 
meridians, 30° apart. The readings were repeated at frequent 
intervals throughout the life of the lamps. The results were 
plotted with polar codrdinates. They show (figure 1), by the 
diminishing area of the successive curves, the progressive loss 
of brightness due to age, of which about one-half is ascribable 
to the coating. The similarity of the curves, from first to last, 
indicates that the coating is deposited uniformly within the 
bulb, or in uniform lateral zones, so that the density of the 
film, is symmetrical with reference to any given meridian. 
The case chosen for illustration is lamp No. 7. The results 
obtained with lamp 8, were in every essential respect the same 
as those shown in the diagram. 


* The lamp was broken before the photometric measurements had been com- 
pleted. 

+See Kruess, Kolorimetrie, p. 243; also, Nichols and Snow, Phil. Mag., V, vol. 
xXxxili, p 379. 

¢ See Franklin Institute Tests (International Electrical Exhibition, 1884), Phila- 
delphia, 1885. 


E.. L. Nichols—Age-.coating rn Incandescent Lamps. 283 


1. 


III. 


The age-coating considered as a factor in the diminishing effi- 
ciency of the lamp. 


It may be seen from the Tables (I and II) that the absorbing 
power of the coating is in itself sufficient to account for a very 
considerable falling off in the candle-power, as the lamp, 
within the bulb of which it forms, grows old in service. 
summation of the values in the tables, we may obtain the 
average absorbing power for the entire spectrum; and since 
selective absorption is almost entirely absent, these averages 
will give very closely.indeed the loss in candle-power, which 
at the time in question was ascribable to the influence of the 
coating. From the data in Tables I and II, also, we may com- 
pute the efficiencies of the lamps at various stages in terms of 
their initial efficiency as unity; likewise their brightness from 
time to time, in terms of their initial candle-power, as unity. 
In Tables III and IV are given, for purpose of j. com parison, 
the relative brightness and efficiency of lamps 2 and 10, at 


284 EF. L. Nichols—Age-coating in Incandescent Lamps. 


various periods, also the average absorbing power of their 
coatings. 


Tasie III. 


Relative brightness, efficiency and transparency of lamp No. 2, at vari- 
ous periods (each expressed in terms of its initial value taken as one 
hundred). 


Relative Relative Relative transparency 
Time. brightness. efficiency. of bulb. 

000° hours 100° 100° 100° 

HOOmE y* 781 81°5 91°44 
Z200F a < 67°5 70°9 85°91 
AOOn gs 60°4 66°8 82°46 
SOO Mea 45°0 d1°3 78°24 

TAB EEE IVE 


Relative brightness, efficiency and transparency of lamp 10, at various 
periods (each expressed in terms of its initial value, taken as 100). 


Relative Relative Relative transparency 

Time. brightness. efficiency. of bulb. 

0° hours, 100: 100° 100° 
50° sf 92°6 92°6 Soe 
109° ss 91°4 90-1 ae 
200° st 86°6 87°3 90°5 
400° <$ 80°5 81°6 sie 
d11° Be 78:7 80°0 ese 
600° SS 78°0 79°5 Sees 
900° £5 She en 85°0 

2 


200h. 400h. —-600h__——800h. 


GO eek Ae ie Magen gi rei me az 


SS SS SS SS SS SS 


SSS SS 


200h ~=9400h = 600h_—s—(s« BOD 


EE. 285 


The curves in figure 2 are based upon these data. They 
show that the loss in candle-power and efficiency are only in 
part due to the opacity of the coatings. It is of some interest 
to compare lamps 2 and 10, since the former is a three watt 
lamp, whereas the other required 5:16 watts per candle at the 
beginning of the test. It is to be regretted that the tests did 
-not extend over the normal life-time of such a lamp; the 
results obtained, however, suffice to show that the loss due to 
coating is a much larger portion of the total loss in the low 
efficiency lamp than in the other. Measurements with several 
lamps, maintained at abnormally high temperatures seemed to 
indicate that the higher the state of incandescence the less 
marked (relatively) is the influence of the age-coating upon 
the decadence of the lamp. 


Summary of results. 


1. The rate of deposit of the coating in incandescent lamp 
bulbs is greatest in the early part of the life of the lamp. 
For example, in the case of a lamp which lasted 800 hours, 
(see Table IIT) more than half of the coating was deposited dur- 
ing the first 200 hours. 

9. The loss of brightness due to the absorbing power of the 
age-coating is a variable part of the total loss, “being greatest 
in lamps of high initial efficiency. 

3. The coating does not appreciably modify the character of 
the ight which emanates from the lamp. 

4, The distribution of the coating within the bulb isa nearly 
uniform one (see figure 1). 

5. No marked difference between treated and untreated fila- 
ments appears to exist, as regards the density or quality of the 
coating produced from them.* 

Physical Laboratory of Cornell University, July, 1892. 


*Since this article was written it has been pointed out by Professor B. F. 
Thomas (in the paper already cited), that in the case of lamps exhausted without 
the aid of mercury the age-coating is scarcely perceptible. 


286 J. S. Ditler—Mica-peridotite from Kentucky. 


Art. XXX VIL.—JMica-peridotite from Kentucky; by J. 8. 
DILLER. 


In November, 1890, I received from Mr. E. O. Ulrich of 
the Geological Survey of Kentucky the information that a dike, 
called the Flanary dike, had been discovered in Crittenden 
County of that State. The specimens from the dike sent to me 
at that time for examination were laid aside awaiting the report 
upon the eruptive rocks of Arkansas by J. Francis Williams, 
and J. F. Kemp. It was expected that similar rocks would be 
found in Arkansas and this paper rendered unnecessary. ; 

Mr. Ulrich has kindly furnished me the following informa- 
tion concerning the occurrence of the rock in the field. 

The dike is in a fault striking N. 44 E. Although the peri- 
dotite has not yet been found all along the fault it is known to 
occur at four points on the line with a distance of 6 miles 
between the extremes. In Livingston county a little was seen 
in a shaft mixed with fluor spar and other vein matter. A 
mile and a half northeast of the county line and three miles 
from the locality just noted, a shallow opening exposes consider- 
able decomposed peridotite of a light gray or ash color. Here 
again it is associated with vein matter chiefly fluor spar. At 
the Flanary shaft the dike is over 20 feet wide with no wall 
seen on either side. Crosscuts were made 6 feet on one side 
and 8 feet on the other without finding the walls. It may be 
that the shaft is at the intersection of several veins in a sort of 
“chimney.” A quarter mile southeast on the Holly the vein 
matter is 6 feet solid and pure fluor spar. The dike break 
separates strata faulted no less than 800 feet with the St. Louis 
beds on the northwest and the upper Chester and coal-measure 
conglomerate on the southeast. 

At least one other dike has been discovered in the county 
and Mr. Ulrich thinks its material is closely related to that of 
the Flanary dike. It occurs in a much tumbled region just 
south of the Columbia mines which he regards as the chief 
center of disturbance. 

The specimens for my study were selected by Mr. Ulrich 
from among the material thrown out of the Flanary shaft. 
The shaft is 45 feet deep and the material exposed to surface 
weathering for nearly two years. The rock is dull greenish- 
gray. At first glance it has a granitic aspect but upon closer 
examination the resemblance disappears. It contains many 
small dark greenish spots besides brownish scales of mica. 
Upon comparing it with an altered specimen of the peridotite 
from Elliott county, Ky., one is led at once to suspect that 


J. S. Diller—Mica-peridotite from Kentucky. 287 


the dark green spots are serpentine and represent original oli- 
vine. A thin section of the rock examined under the micro- 
scope confirms the conjecture. 

The rock is composed essentially of biotite, serpentine, and 
perofskite with a smaller proportion of apatite, muscovite, 
magnetite, chlorite, calcite and other secondary products which 
cannot be definitely determined. It is possible that originally 
there may have been some pyroxene present. The biotite is 
somewhat in excess of the serpentine and together they form 
nearly 75 per cent of the whole rock, small crystals of perofskite 
are abundant but their total mass is less than that of the brown- 
ish-gray clouded material supposed to be of secondary origin. 
Opaque black grains of magnetite are rather common and a 
few clear crystals of apatite as well as scales of chlorite and 
muscovite and small veins of fibrous calcite are present. Judg- 
ing from the chemical analysis there is probably considerable 
chromite present also. 

If we consider only the relation of the large scales of biotite 
to one another as determining the structure of the rock it is 
granitoid for the biotite is allotriomorphic. This mineral is 
yellowish brown to almost colorless. It occurs in round or 
oblong patches averaging about 4"™™ in diameter and forms the 
groundwork of the rock. Within these irregular scales are 
scattered the crystals and grains of serpentine in such a way as 
to render them peecilitic on a cleavage face. The biotite here 
plays essentially the same role as the hornblende and augite in 
the picrites. Between the larger scales, scattered here a few, 
and there many, throughout the brownish-gray clouded matter 
are smaller scales of biotite. In sections of the biotite perpen- 
dicular to its basal cleavage, although its colors between crossed 
nicols are brilliant its absorption is very feeble even less than 
that of ordinary brown hornblende. Prof. Rosenbusch sug- 
gests that the absorption is too small and the bisectrix too 
oblique for normal biotite. The biotite is occasionally altered 
to chlorite. 

The serpentine is distributed uniformly throughout the rock 
in irregular rounded or angular grains averaging about 1™™ in 
diameter. The characteristic sections with outlines like those 
of olivine parallel to the base and macropinacoid are sufficiently 
numerous and well defined to clearly indicate that the serpen- 
tine originated from the alteration of olivine. The large 
quantity of olivine originally present shows that the rock 
belongs to the peridotites. 

The mineral regarded as perofskite is abundant and generally 
well crystallized. The diamond-shaped, square and triangular 
sections which are completely isotropic demonstrate that it is 
isometric. Its color is honey-yellow and only moderately 


288 J. 8S. Diller—Mica-peridotite from Kentucky. 


transparent. The crystals vary in size from 01" to 1™™ in 
diameter and are almost always black-bordered. The chemi- 
cal analysis of the rock shows that it contains 3°78 per cent 
TiO, with 9-46 per cent CaO. After taking out of the analysis 
the elements demanded for the other determined minerals 
there yet remains essentially the composition of perofskite. 
Titanic acid is frequently found in biotite and it is desirable 
that analyses be made of both biotite and perofskite in this 
case; but as the minute crystals of perofskite are generally en- 
veloped by the biotite it would be very difficult and perhaps 
impossible to satisfactorily separate them. 

The muscovite, chlorite, magnetite, apatite and fibrous eal- 
cite have no features deserving special mention. ‘The brown- 
ish gray clouded material which is next in abundance to the 
serpentine is scattered thronghout the section generally between 
the scales of biotite, but often within them. It is without 
crystallographic outline or such physical features as definitely 
indicate its origin. 

The following chemical analysis of the rock for which I am 
greatly indebted to Mr. W. F. Hillebrand was made in the 
chemical laboratory of the U. 8. Geological Survey. 


SiOkysts ange Pawlhiga lik (yams etea ged 
Oe vt eo eee eie ly aiken 3°78 
PA Oa ie Bid ae yd aap ak Oper rte So 5°88 
ONC (8 Dir Soe ReD ee ene PS. ei Sa 0°18 
LENE GRC ete ge 2 ley = Ser 7:04 
1 Oh ey @ Saad in I Ned Mao ehh auld Es abe Rabon. 550119 
EVE rece Some Wester ee ease een eer tees Spe ee 0:16 
INT OSE Ea hat eee en eae ey ee en ce Or1 
OPEL G gem AN EE oe Mins AAR ido OPS Seek Ak ost ok tl 
COR LO sO A Aa ERNE et eel By Sea 9°46 
BuOraee 20 fe. OES SAIEE Cenrks cMOR0G 
Mo@ns:dits. (ube eats ain etapa 22°96 
Ka O indie ea Mae gen Ce OR 2-04 
INO)! aU UE A EE pea a 0°33 
FO pit te a ps ee Bey ae oe ae 0) 
Pinay edicres id. ae iey ACN gC eagles 0:89 
OME a ag arte DO i oc teh ae ea 0:05 
] SEE Pe eet ee isa Shel erate sere 52'S 2 ? 
(C0 eee aes Sacer ee Oo 0°43 

99-86 


In addition to the water given, the sample lost 0°68 per cent 
water at 100° C. The large percentage of H,O and CO, shows 
the highly altered condition of the rock. 

Among the peridotites already described Rosenbusch has 
recognized six forms. Considering only their essential constit- 


J. S. Diller—Mica-peridotite from Kentucky. 2389 


uents, the designations adopted by him are as follows:— 
picrite = olivine+augite, amphibole pricrite = olivine+amphi- 
bole, Wehrlite=olivine+diallage, Harzburgite=olivine+rhom- 
bic pyroxene, Lherzolite=olivine+diallage+bronzite, dunite= 
olivine+chromite without pyroxene or amphibole. 

Heretofore* no peridotitic rock has been recognized in which 
biotitet has played the role of an original essential constituent. 
While it is evident that the Flanary dike rock belongs to the 
peridotites, it is clearly excluded from any of the subdivisions 
above. In order that it may be conveniently distinguished 
from other peridotites I propose for it the name mica-perido- 
tete, a name which | believe will at once suggest to all students 
of petrography its kinship. 

More than half a decade ago Prof. A. R. Crandallt dis- 
covered the peridotite of Elliott county, Kentucky, and to this 
Mr. Ulrich now adds one more of the same type of rocks from 
the western part of the State. Closely related rocks of the 
same group have been described by Drs. J. C. Branner$ and 
R. N. Brackett from Pike Oo., Ark., by Prof. G. H. Williams,| 
from Syracuse, N. Y., and by Prof. J. F. Kemp,{ from Ithaca, 
NESEY: 

A very fresh olivine mica rock closely related to the mica 
peridotite of Kentucky has been described by Dr. Max Koch,** 
who recognizes itasanew type. It occursin the gabbro region 
of the Harz and contains augite and plagioclase as accessory 
minerals in small quantities’ These minerals as well as the 
geologic relations of the rock indicate according to Dr. Koch, 
that it belongs to the gabbro group. 

U. S. Geological Survey, Washington, D. C. 


* Excepting perhaps one described by Max Koch which will be noticed later. 

+ The peridotitic rock described by Judd (Quart. Jour. Geol. Soc., Aug., 1885, p. 
401), as scyelite is rich in mica; but he regards it as secondary resulting from the 
alteration of augite. Furthermore, scyelite contains hornblende of which not a 
trace has been found in the rock from Flanary dike. 

¢ Geol. Survey of Ky., Report on the Geology of Elliott County, by A. R. Cran- 
dall, p.17. See also articles by J. S. Diller, this Journal, Aug. 1886, and U. S. 
Geol. Survey, Bulletin No. 38. 

§ This Journal, vol. xxxviii, p. 50, 1889; also, Geol. Survey of Ark. Annual 
Rept. for 1890, vol. ii, p. 377. 

| Ibid., vol. xxxiv, pp. 140-142, 1887. 

§] Ibid., vol. xlii, p. 410, 1891. 

** Zeitschr. d. d. geolog. Gesell., xli, p. 163, 1889. 


290 D. FF. Lincoln— Glaciation in the 


Arr. XXX VITI.— Glaciation in the Finger-Lake region of 
New York; by D. F. Lincontn, M.D., Geneva, N. Y. 


THE Appalachian plateau, at the line between New York 
and Pennsylvania, is composed of Upper Devonian sandstone 
and sandy shale, dipping slightly to the south, with summits 
2000-2500 feet above tide level. ‘The valleys are rather deep 
(400-800 feet), and resemble in a general way those of central 
Pennsylvania, but without the N.E.—S.W. parallelism of the 
latter. The elevations do not take the form of ridges; they 
consist of broad, clumsy masses, diminishing in steepness as 
they ascend, and capped with irregular rolling plains. 

The Susquehanna, with its tributary the Chemung, here 
forms an important depression, north of which the land rises 
to the height of 2000 feet, again sinking to form the basin of 
the Finger Lakes. The lakes therefore occupy a section of 
the northern slope of the Appalachian plateau, which may be 
defined as extending 100 miles E.—W., from the Genesee 
Valley to Cazenovia Lake, and about 70 miles N.-S., from 
Lake Ontario to the curved line of high land just south of the 
lakes. 

This line of heights corresponds in position with the 
“Terminal Moraine of the Second Glacial Epoch” of Cham- 
berlin,* and is defined as a water-parting by the following 
high points—Bristol, 2254 ft.; Urbana, 1940; Orange, 2033 ; 
Newfield, 2095; Dryden, 1888; Virgil, 2133; Solon, 1977; 
Fabius, 2015; Fenner, 1862.+ 

The height of land of which these are the summits is cut 
through by many deep straight valleys, which on the south 
communicate with the Chemung-Susquehanna valley, while on 
the north they converge toward a common imaginary center 
in Lake Ontario. The northerly discharge is intercepted by 
streams flowing eastward, which unite to form the Oswego 
River. Most of these north-south valleys are so blocked with 
drift as to form lakes. 

The middle of the common basin is axially depressed, in a 
north-south direction; the depression is occupied by the two 
largest lakes, Seneca and Cayuga. 

There is a considerable system of minor, preglacial valleys 
still traceable in the elevated tracts between the lakes. This 
system, however, has been so disturbed by glaciation that it no 


*U.S. Geol. Survey, Third Report. 
+ Triangulation of N. Y. State Survey, 1883, 1887. 


Finger-Lake region of New York. 291 


longer furnishes in normal fashion a series of tributaries to the 
lakes. The greater part of the surface water enters the lakes 
through torrents, running from two to four miles in a straight 
course, at right angles to the lake-axis, through precipitous 


L. ONTARIO. 


— 


NGS: Zenovia iL. 


The Finger-lake region of New York. 


Terminal moraine (from Chamberlain) is represented by dots.—Corniferous 
limestone, a line of dots.—Tully limestone (Prof. H. S. Williams) dots and 
dashes —.—. : 


A, Bristol ; B, Urbana ; C, Sugar Hill ; D, Hornby ; 
K, Orange; F, Newfield; G, Dryden; H, Virgil; 
J, Richford; K, Solon; L, Fabius; M, Fenner. 


Elevations above sea-level—Rochester, 508; Lyons, 407; Clyde, 396; Bath, 
1105; Elmira, 863; Sugar Fill, 2091; Hornby, 2045; Richford, 1995. 


gorges, which they are still actively deepening. Some of the 
finest scenery in the State is found in these gorges. Watkins 
and Havana glens are examples; the highest waterfall in the 
State occurs in the Taughannock glen, near Ithaca; its per- 
pendicular fall is 190 feet. 


292 D. F. Lincoln— Glaciation in the 


Altitudes and Depths of Lakes. 


Elevation above tide. Greatest depth. 
Hire tie ath see AS ate] be RD Y) L 210 G 
Chautauqua! =] 2222-22 e) L291 G 
@onesusm eee aes 821 R 70G 
Hemlock. ee eee * 898 R 87 G 
Canadices= aaa 1099 R 87 G 
Honeoye!) tae 2 eee less than Hemlock 25 G 
@Canandaioway - 222-252 668 G 
Keuka (Crooked) ... -- 718’ 10” G 
Semec ad ys Me: CRN MMe 44] C 618 M 
CayuGapeeterc see = Senos C 435 M 
OwasGowgs eee ee as 670 G 

860 G 
Skaneateles=-2. 22.2. 864’ 12” 

861 C 
Otiscosrn aieas cee es a no data 
@azenovilae eee ee 900 G 
Schuylew eas ane ae 1200 G 
Otsecopa ea ee eee 1193 G 
Onondaga a aeeee a 361 G 

369 G 
Onerd ag seo es women Oral 

368 C 
OMG arith J. users) eet to 246 L 738 


L = U.S. Lake Survey. C= Resurvey of N. Y. Canals. R = Rochester 
Water Works Surveys. P = Penn. & N. Y.R. R. G = French’s Gazetteer of 
N. Y., 1860 (comparatively poor authority.) M=Soundings given on map pub- 
lisked by Engineering Department of Cornell University. 


The entire basin may conveniently be divided into three 
regions or zones, nearly corresponding with certain geological 
formations. The northern zone (Silurian) is nearly devel, with 
a heavy mantle of drift; it extends from the Ontario coast to 
the northerly escarpment of the Corniferous limestone, which 
is skirted by the line of railroad passing through Auburn, 
Geneva, Canandaigua, and Miller’s Corners. The middle zone 
comprises the moderate ascent of the lower Devonian, ‘extend- 
ing south from 6 to 20 miles from the railroad. The southern 
zone, with steep slopes and deep valleys, comprises the Upper 
Devonian (Chemung and Portage rocks), including on the east 
the lower Devonian to Skaneateles. The zigzag dotted line of 
the Tully limestone partially indicates the demarcation between 
the two latter zones. The terminal moraine bounds the whole 
on the south. 


Finger-Lake region of New York. 293 


The northern zone comprises the Medina, Clinton, Niagara, 
and Salina formations, dipping south at a low angle. The 
Clinton and Niagara limestones form pcan: facing north, 
which are inconspicuous in large part. It is traversed by the 


Genesee R. 
Miller’s Cor 
Canandaigua. 
Geneva 
Cayuga. 
Auburn 
Skaneateles. 
Syracuse. 


les) 
— 
i 
= 
Cx 
(ee 
= 
= 
Ss 
2 
a 


Tede 
Sa Addn 4H 4 eel Sect tah har rurel al Lota h 
m oo bs) 3 ow] ima 3 fo) “tee AE a) sr 3S (=| 
& 5 eS eos “ 8 ° Eel 1S) aa SS a. 5 5 
2 ic etl = s 5 
ge (Sagas 5 A Sr ental elie FR ROC 
aq 42 qSq io} 3 A i) Se S&S ¢& x a 
ge a {Se} = -& (o) ey 
S ENO i) S wn Olas eS ) 
wu O Oa > =I Rn ra N 
qo x 3S = 3 
: 3 : 
= n 
'o) 


A. Vertical section nearly H.-W. along N. Y. Central R. R., nearly on Cor- 
niferous outcrop. 


B. Vertical section near the middle of each lake ; dotted lines show deficiency 
of exact data, partially supplied by a few adjacent known points. 


N. Y. Central R. R. and the Erie Canal at very easy grades. 
A portion along the southern edge of this belt is level and 
free from drift-hills: north of which the surface is diversified 
by an extraordinary series of drumlins, already described by 
Hall (New York State Geological Report for 4th Dist., 1842) 
and Johnson (“Parallel Drift Hills of Western New York ;” 
Annals, of IN.-Y. Acad. of Sei.; Nov. 9; 1882)., These are 
stated by Hall to be bounded northerly by the beach of the 
ancient Lake [roquois—the ‘“ Ridge Road ”—which runs a few 
miles from the shore of Lake Ontario. 

As compared with the drumlins of New England, these are 
of much greater length, are relatively much narrower, much 
sharper at their ridges and steeper in their side-slope. Their 
northern ends are very bluff, their southern ends gently 
inclined. Their axes lie nearly north and south, on the whole, 
with marked local differences. 

The width of these hills at top is often sufficient to receive 
a country road without much leveling, but some would not (in 
their original state) admit the passage of a single cart along 
the ridge; while in exceptional cases there are flat tops some 
hundreds of feet in width. 

The inclination to the south is often so gentle as to have no 
definite ending; thus many hills which begin northwardly 


294 D. F. Lincoln—Glaciation in the 


with well-marked drumlin-outlines sink and broaden south- 
wardly into plains of till. Some, however, are well-defined at 
both ends, and in length fall within one-half or two-thirds of a 
mile. Johnson states that the best developed ones run two or 
three miles, and reach the height of 100-200 feet above the 
plain; that they are highest and longest chiefly just south of 
the Niagara escarpment, though there are a few very high 
ones more to the south. 

Measurements of a few of the steeper ones (kindly com- 
municated by Mr. George H. Barton) show the inclination of 
the sides to be about 23°, and only exceptionally 25°. 

The material of these hills is a till, possessing the usual 
characteristics—unless a tendency to the formation of very 
deep gullies (5-15 feet deep) on the sides be considered excep- 
tional. Some are covered very thickly with good-sized trav- 
eled stones; some with sand or gravel of varying depth. In 
the neighborhood of Rochester are some of which the nucleus 
is sand, till forming the upper part. Considerable kame-de- 
posits are associated with the drumlin-belt at some points, and 
near Rochester a portion of the moraine traverses it. 

The writer’s personal study of this region is limited to five 
localities, and the above statements are in part drawn from 
other sources. An excellent cursory view can be had from 
the car windows as the traveler passes east from Rochester on 
the main line of the N. Y. Central R. R. via Lyons and Clyde 
to Syracuse. 

This belt of darge drumlins practically comes to an end at 
the distance of twenty miles from Lake Ontario. Then come 
low lands, partly sandy, partly marshy. Still farther south, 
within the middle zone, the drumlin-formation is resumed, in 
ridges of much smaller height, but in considerable numbers. 
As this point has not met the writer’s eye in print, attention is 
here called to it, and some special observations are offered. 

Among the drumlins of the second range (in the middle belt) 
there are some which resemble the typical “lenticular hill” of 
New England. More, however, are of the ridge variety. And 
of the latter there are many grades, from the very well marked 
ridge with rather steep banks to very low ridges which are 
often so low and flat as to simulate terraces. The face of this 
part of the country is laid out in shallow grooves, often pro- 
ducing the strong impression of “ fluting.” 

An instructive group of these ridges occurs in and around 
the town of Geneva. They are very nearly parallel, their axes 
lying between 10° and 15° west of north. The easternmost 
skirts the lake, and is somewhat eroded by the waters, display- 
ing sections of till, with limited beds of blue clay and “ quick- 
sand.’ Its erest,on which Main street is built, reaches a height 


Finger-Lake region of New York. 295 


of 90 feet above the lake. The other ridges increase in absolute 
elevation, but not in size, having an apparent height of 20-50 
feet above the ascending slope which they cover. At some- 
what over a mile from the shore they attain a height of 300 
feet above the surface of the lake, which corresponds with the 
verge of the higher levels of land. Similar ridges are found 
_ for several miles farther west; sometimes crossing the road 
at pretty regular intervals of 4 to $ mile, with elevations 
of only a few feet; at other One forming hills with a rather 
bold northern descent. 

A distinct termination north and south can generally be 
traced in the ridges of the Geneva group, although the ordi- 
nary observer is inclined to overlook the fact. Their general 
outline, their material, and their tendency to steepness at the 
‘north end, ally them with the drumlins of the northern belt. 
The long ‘ridge running west from the end of the lake is of 
typical till, with some large bowlders, overlaid in part by 
stratified sandy clay. 

In this locality, the till evidently forms a continuous sheet, 
of which the ridges are merely a surface irregularity. 

The slope of the sides of the ridges is about from 2° to 10° 
at Geneva, and their crests are occasionally from 100 to 300 
feet wide. 

- The direction of the ridges of till as a whole is probably 
similar to that of the glacial striations, that is, convergent to a 
northerly poimt. At Clyde and Lyons (on the central axis of 
the region) they run a degree or two west of north. Near 
Cayuga, about N. 8° W.; and still further east, about 20° west 
of north. 

The till at Geneva is a firm “ hard-pan,” containing a great 
number of subangular striated stones of all sizes up to three 
feet in length. The greater part of the stones are from the 
Corniferous limestone, which is exposed just north of the vil- 
lage. Of those representing more northern formations, many 
are water-rolled. The limestone fragments give a bluish tint 
to the otherwise reddish brown mass. 

About three feet of the upper part of this till appears thor- 
oughly oxidized and leached. This portion is a red clay, dis- 
tinetly contrasted with the gray-blue till, and rather well 
demarcated. It is of a deep shade, unstratified, very tenacious, 
nearly free from sand; at times flaky, at times tending to split 
when dry into rectangular forms. It cuts with a slight gritti- 
ness ; the surface is dotted with occasional specks of material 
not fully decomposed, which may represent some of the 
myriads of little bits of limestone found in the till. The 
stones are few, chiefly such as resist oxidation (quartzites) ; 
these correspond in appearance and amount with a simliar 


Am. Jour. Sci1.—Tuirp Series, Vout. XLIV, No. 262.—OcToBER, 1892. 
20 g 


296 D. F. Lincoln—Glaciation in the 


ingredient of the till. Gneisses and schists are absent, or 
badly rotted. The forms are characteristic of till, and in some 
cases striation is observed. A part of the stones react feebly 
to HCl; the clay does not react. 

Midway of the Cayuga lake shore, on the east side, there are 
fine till sections which give a similar result on analysis. 

The same leaching of the upper part has been observed in 
stoneless sedimentary clay of Geneva. Absence of the lime- 
reaction is stated to be characteristic of the soil at the State 
Agricultural Station in the same town. 

At many points on the surface of the lower-till (Drumlin) 
deposits just described, there is little or none of the englacial 
material defined by Upham.* But where the stones lie thickly 
in the fields it is necessary to suppose that they are chiefly of 
englacial origin; for the proportion of limestone fragments in 
such cases is quite too small to permit us to refer them to the 
lower-till. This is easily seen in the piles of stones which the 
farmers draw from the fields—sometimes 12-20 feet in diam- 
eter from a 100-acre lot—consisting mostly of gneissoids, 
schists, and quartzites, with perhaps one-fifth corniferous lime- 
stone, the lumps varying from 2 to 200 pounds in weight. 
The larger stones (bowlders) carry out this statement; they are 
almost all far traveled stones. Large bowlders are not very 
frequent. The largest within observation are one of labrado- 
rite (7X7 feet), and one of an argillaceous rock from the 
Salina beds (6X11) which is exceptional in having traveled 
only 5 or 6 miles. 

Stratified deposits are not infrequent, however, upon the 
drumlin formation. Rolled gravel is not rare, and the kames 
and osars deserve a fuller description than can here be given. 

On reaching the higher levels, west of Geneva or east of 
Aurora, we often find the surface sandy. The sand even takes 
the form of low hills and ridges. The deposit of tough lower- 
till, however, is still found beneath the light top-soil. 

The thickness of the till-sheet at Geneva is reported at seve- 
ral points as 20-80 feet. Sand lies beneath this, and still 
lower, till again. At one well, there was 14 feet of sand, and 
13 feet or more of the deeper till bed. Layers of vegetable 
matter, and blue clay, are also found. 

In passing south from the soft shales of the Hamilton group 
to the sandy shales and hard fissile sandstones of the upper 
Devonian beds, we are informed of the change of bed-rock by 
the alteration in the character of the lower-till. The latter, in 
recent exposures, may be very tough, but is sandy rather than 
clayey. ‘The enclosed stones are sandstone, rarely limestone. 
Fragments handsomely glaciated occur as large as three feet 


* Amer. Geologist, vol. viii, No. 6. 


Finger-Lake region of New York. 297 


long. The field-stones in this region split, losing their like- 
ness to till-stones. Hence the “flat gravel,” characteristic of 
the soil of the hilly districts. 

The deltas of the lake sides are among the most conspicuous 
accumulations of drift material. Rising at intervals along the 
sides of the lakes and the southern continuations of their val- 
- leys, they attain by a series of steps the height of (?) 400 feet 
above the lakes. Their strata contain many stones which still 
show half obliterated glacial striz. 


The remainder of this paper will be devoted to certain points 
of preglacial topography and drainage, and the associated 
questions of amount of glacial corrasion, and bulk of drift- 
deposit. The northern zone, except as specially designated, 
will be omitted from consideration. 

The deposits of the terminal moraine are very heavy; for a 
description of this feature the reader is referred to the paper 
on this subject by Thomas OC. Chamberlin. 

From considerable examination of the country included 
between the four larger lakes, the writer has been led to set a’ 
moderate estimate upon the amount of drift, and a very high 
estimate upon the amount of erosion in cer tain parts. 

The lakes are to a great extent bordered by vertical cliffs of 
rock, with little or no beach'at their foot. Owing to the 
greater prevalence of westerly winds the cliffs are best developed 
on the east side. In the case of Cayuga Lake this natural facil- 
ity is aided by the presence of a railroad at the water’s edge, 
for which in many places the cliffs have had to be cut. From 
Aurora southward for nearly 20 miles the top of the cliff is 
visible most of the way, undulating in very moderate curves, 
occasionally rising 50 feet or more, and at several points sink- 
ing below the level of the lake for short distances. In the 
latter case the rock is exposed in brooks a few rods inland. 
Till overlies this rock, varying in thickness from 2 to 40 feet. 
The till deposits along the east shore of Seneca lake are appar- 
ently not much in excess of the above. 

It is probable that the rock-sections thus displayed correctly 
represent the general surface of the region as it would appear 
if the drift were removed. In ‘some tracts, at all events, this 
is demonstrably the case. In the northern reaches of the lakes, 
hills of rock with a very flat curve correspond with these cliffs. 
A few examples may be worth describing. At the foot of 
Seneca Lake on the east side there is a line of cliff (Marcellus 
shale), which rises gradually to a height of 25-30 feet and ex- 
tends more thana mile. ‘A hill-side rises directly from the 
brow of this cliff to the height of about 90 feet; mainly rock 
with 2-20 feet of till. Three miles to the southward is another 
long shore-cliff of rather greater height, the land behind which 


298 D. F. Lincoln— Glaciation in the 


rises for 14 miles eastward, reaching a height of 150 (?) 
feet, and forming a broad-backed N-S ridge of Hamilton shale 
covered with a couple of feet of drift. A third ridge 250 feet 
high, at a similar interval to the 8.E., slopes very evenly to the 
lake (24 miles distant) over rock covered with a very few feet 
of drift; in this case no cliff is formed, the rock not quite reach- 
ing the lake. The axis of this hill points N. 20°-30° W. 
On Cayuga lake, south of Aurora, there is a hill 300 feet in 
height, forming a cliff at the lake-side, two miles long and one 
mile across, with its long axis directed N.W.-S.E., composed ~ 
of Hamilton shale. The top of this hill, co the length of a 
_ mile, forms a plateau. A smaller hill of Marcellus shale lies 4 
miles to the north of this. 

In the present state of the question it is admissible to sup- 
pose that these hills may be remnants of preglacial hills of 
bolder outline. The fact that they lie parallel to the lake need 
not militate against this view, since the old valleys of the 
region—farther south than the hills described—unite with the 
lakes and with each other at very acute angles. 

The hills may constitute a very insignificant remnant of old 
hills; or may even have been car ved out de novo from rock 
which occupied levels below the roots of their predecessors. 
In other words, the corrasion at the latitudes of Geneva and 
Auburn may have removed one hundred or several hundred 
feet. Definite evidence limiting these estimates is not before 
me. Apart, however, from the numerical estimate, it is interest- 
ing to note the parallelism between the axes of these hills and 
those of the drumlins which are found close by. Their mate- 
rial, a soft shale, yields readily to force applied horizontally, 
and it is not beyond the province of legitimate speculation to 
suggest that their forms may have been carved at the same 
time and in similar circumstances with the drumlins. Their 
bluffer northern sides, and their exceedingly gentle southern 
slopes, add much to the likeness. 

A system of small valleys for local drainage, opening lake- 
ward, doubtless existed before glaciation. We can point to no 
surviving representatives of these valleys at the lake level unless 
the slight depressions in the cliff line be taken as such. These 
descending curvesrun but a short distance below the lake level, 
and represent but slight inward bends of the rock-shore. If the 
lake were drained, the present mouths of the brooks flowing in 
these hollows would be a mile from the main stream which 
presumably oceupied the axis of the valley. In going this 
mile they would fall from 3800 to 600 feet. Such streams 
must have cut deep and wide gorges extending far inland. 
How deep some of these would have been at parts of the lake 
where the shores are bolder, may be estimated by considering 


Finger-Lake region of New York. 299 


that the land at the upper part of Seneca lake rises in six miles 
to upland pastures nearly 2000 feet above the bed of the lake.* 
The continuity of cliffs for 15 miles along the west coast near 
Watkins, and the frequency of rock exposures on the BIEL 
lands, forbid the belief that such gorges exist. 

The inference from these considerations is that the pre- 
_ glacial river which has been developed into Seneca lake must 
have oceupied a level many hundreds of feet above the present 
bed of the lake. 

Some drift-buried valleys certainly exist. One such, prob- 
ably. with a meridional course, seems to lie to the east of Aurora, 
where two E.-W. ravines appear to cut it, one of which ex- 
hibits a till-section 100 feet thick, with bottom not reached. 
However this be, there still exists a large system of valleys, 
with banks several hundred feet high, subsidiary to the lake 
valleys and in several places communicating withthem. These 
valleys are rock-cut, and often show rocky bottoms; they run 
mainly parallel to the lakes, but occasionally branch in a trans- 
verse direction. They run straight through the line of terminal 
moraine. Their trough-like aspect north of the moraine points 
to probable widening and deepening, as in the case of their 
much bigger brothers, the lakes. 

As an illustration, take the large valley, 20 miles long, enter- 
ing Cayuga lake 6 miles north of Ithaca. It is cumbered with 
some drift, but its walls rise 400 feet above its bed, in full 
sight from the lake. 

Perhaps the case of certain upland valleys will add con- 
firmation to these views. East of Watkins there is a system 
of these at 400-600 feet above the lake. The main drainage 
of this system is at present southward, but it communicates 
with the Seneca valley by two wide gaps, allowing several 
short streams to enter the lake, which they do by a sudden 
plunge—one of them cutting the beautiful Havana glen in its 
descent. These streams must have fallen 1,000 feet in three 
miles in order to have reached the Seneca valley bottom at its 
present level. In like manner the stream which has excavated 
the celebrated Watkins Glen descends about 500 feet in its 
last mile through a canyon with vertical walls, while its upper 
five miles are mostly in an old valley with moderate grades. 

Again, Dundee, situated three miles from the west shore 
and ten miles north of Watkins, stands 600 feet above Seneca 
lake. It occupies a site apparently near the mouth of an old 
valley, bounded by rock-hills from 300 to 400 feet high, and 
displaying a rocky bottom in the stream at Dundee. The 
valley has four or five branches, extending six miles above the 


* Seneca lake bottom is 177 feet below tide; high points W. of Watkins, near 
2100 feet above tide. 


3800) =D. F. Lincoln—Glaciation of Finger-Lake, ete. 


village in several directions, with very moderate grades. In 
the direction of the lake the valley-sides become lower, and 
the valley itself disappears, debouching upon the lake side at 
an imaginary plane in mid-air. From this point the lake-side 
descends smoothly and rapidly, while the stream, with many 
cascades, falls 500 feet in two miles. 

If these valleys, or any of them, had a preglacial existence, 
and a rational connection with the lake valley, it would seem 
necessary to suppose that the bed of the latter then stood at 
an elevation 800 (?) feet higher than at present. If they 
drained away from the lake, they would soon have been, cut 
down by robber-streams falling into the Seneca valley. The 
present Chemung river valley, which would be the southerly 
exit, is 1200 feet higher than Seneca valley floor. 

The trough of the present lake runs straight south from 
Watkins to the open valley about Elmira, 22 miles distant. 
The present bottom of the lake is 1,000 feet below the river at 
Elmira ; a discrepancy which may be harmonized by either of 
two hypotheses,—glacial erosion of the lake bed, and filling of the 
valley at Elmira with overwash from the moraine. That the 
truth is a composite of both, seems very probable. 

The belief that the lakes are deeply gouged by ice is con- 
sistent with the fact that their depth (in the case of the two 
largest) is much the greatest in the southern third. Con- 
sidered relatively to the glacial movement, this is the down- 
ward part, and the fact agrees with Geikie’s statements 
regarding the rock-cut lochs of western Scotland, which form 
basins, deepest toward their outlet. The section of Seneca 
lake along its axis is like that of an elongated tablespoon, 
pointed to the north. But until we know more about the 
depth of alluvial and drift deposit at the ends of the lakes, 
this consideration may be waived. It is nearly certain, how- 
ever, that the lake bed is not more than 800 feet deep at 
Geneva where the apparent depth is 40 feet. 

The direction of preglacial dramage may perhaps be inferred 
from the considerable and continuous slope of the land toward 
Lake Ontario. The height of land between this slope and 
that toward the Susquehanna system is near the south ends of 
the lakes, and it does not seem necessary to suppose that it 
was formerly placed much farther to the north. Such valleys 
as Seneca may have had their divide near the southern ends 
of the present lakes. A number of streams seem to have 
run southward across the divide; of which Kenka lake, and 
much of the distribution of the valleys about Canandaigua 
and Owasco lakes, offer strong suggestions. 

Few borings have been made north of the lakes, and it is 
not advantageous to speculate upon a possible outlet for the 


Gooch and Danner—Interaction of Fotassium, ete. 301 


north-flowing streams. The lowlands north of Cayuga lake 
(Montezuma marshes) offer a very slight barrier to such a dis- 
charge. It is worth noting that a boring made at Geneva, at 
the lake side, encountered obstacles from bowlders at about 
100 feet, and struck no true rock until 240 feet below the 
water line. A valley three miles wide between existing rock- 
_ exposures, and 300 feet deeper than the present lake surface, 
apparently opening to the north, is indicated at Geneva: some 
of this depth may be ascribed to glacial action. 


S00 fact 


10 000 feet ’ 


Section of Channel of Wisconsin River (Report of U.S. Geol. Sur., VI, p. 230) 
partially filled with river-gravel; compared with that of Seneca Lake at deepest 
point. The latter section is adapted to scale from that given on the map pub- 
lished by Cornell University; the dotted slope of bank is obtained from contour- 
lines of map. Ratio of vertical to horizontal scale nearly = 10: 1. 

The accompanying cut is given to show the contrast between 
the much-glaciated banks of Seneca Lake, with thin smooth 
gentle curve leading to the upland levels, and the unglaciated 
banks of the Wisconsin River, falling at a sharp angle from 
the level of the plain in which the valley is cut. The section 
is from one of the narrower parts of the river, in its course 
through the non-glaciated region. The river valley is filled to 
an unknown but considerable depth with material brought 
from glaciated territory. The lake valley, judging from the 
outline given, is free from heavy glacial or postglacial deposits 
for many miles; its ends, however, are deeply filled. 


Art. XX XIX.—On Certain Points in the Interaction of Po- 
tasseum Permanganate and Sulphuric Acid; by F. A. 
GoocH and E. W. DANNER. 


[Contributions from the Kent Chemical Laboratory of Yale College—XVII.] 


In an article published some years ago by Mr. Francis 
Jones* upon the action of reducing agents upon potassium 
permanganate the statement is made that in the interaction of 


* Jour. Chem. Soc., xxxiii (1878), p. 95. 


302 Gooch and Danner—Points in the Interaction of 


oxalic acid and the permanganate in whatever way the condi- 
tions were varied—whether there was excess of oxalic acid or 
of permanganate, whether the solutions were strong or dilute, 
whether acid was present or not—in every case oxygen was 
obtained as a product of the reaction. The action between 
the permanganate and ferrous salts, in presence or absence of 
acids, in dilute or strong solutions, was said to yield oxygen 
similarly. In the discussion which followed the reading of 
this paper before the Chemical Society (London) some adverse 
comment seems to have been developed.* 

More recently,t in developing his excellent volumetric - 
methods for the estimation of tellurium, Professor B. Brauner 
has noticed a similar effect in the action of: potassium per- 
manganate upon tellurous oxide dissolved in sulphuric acid, 
and has shown, further, that in this particular case the evolu- 
tion of oxygen is proportional to the amount of sulphuric 
acid employed, and that in working with alkaline solutions 
little evidence of such action appears. 

The production of permanganic acid, and secondarily of 
free oxygen and ozone, by the action of strong sulphuric acid 
upon a permanganate is one of the commonest of phenomena, 
and the formation of a precipitate consisting largely of 
hydrated manganese dioxide by the action of hot dilute sul- 
phuric acid upon the permanganate in aqueous solution is 
likewise well-known. It seemed desirable to us, therefore, to 
study further the action of sulphuric acid of different strengths 
upon the permanganate in solution. with a view to determin- 
ing how far such action may be responsible directly or indi- 
rectly for the liberation of free oxygen in oxidations brought 
about in the presence of the acid. In the first set of experi- 
ments directed to this end we determined the amount of potas- 
sium permanganate remaining after exposure to the action of 
sulphuric acid during different intervals of time and under 
varying conditions of strength and temperature. The per- 
manganate was used in approximately decinormal solutions 
(8:16 grms. to the liter) the exact strength of which was 
determined relatively to an approximately decinormal solution 
of oxalic acid. In fixing the standard small portions (usually 
10 cem*) of the oxalic acid were diluted to a volume of 100 em* 
by means of sulphuric acid of two per cent strength by vol- 
ume, the solution was heated to 70° C. or 80° C., and the 
permanganate was added as usual until the first permanent 
blush of color appeared. 

The general mode of proceeding in the test experiments 
was, in brief, to mix the solution of permanganate with the sul- 


* Ber. d. d. Chem. Gesell., 1878, p. 257. 
+ Jour. Chem. Soc., 1891, p. 238. 


Potassium Permanganate and Sulphurie Acid. 303 


phuric acid (always previously diluted with an equal volume of 
water, and cooled) and, after the lapse of time indicated to 
add oxalic acid in quantity a little more than sufficient to 
bleach the entire amount of permanganate, warm to about 80° 
C., and titrate the residual oxalic acid by gradual addition of 
more permanganate. The difference between the amount of 
permanganate needed under the conditions to destroy the 
known amount of oxalic acid and that used in the determina- 
tion of the standard shonld measure the oxygen lost by the 
permanganate under the action of the sulphuric acid. The 
results and details of these experiments are given below. 


TABLE I, 
Percentage of 
Percentage of K.Mn.0¢ 
K.Mn,0; H2S0, [1:1] used as com- 


H2S0O, in decinormal in solution pared with that 
[le] Water. solution. during action. required by theory. 
em? em? em? em? 
A. 
Treated immediately. 
2 8 10 10 100 
4 6 10 20 100 
6 4 10 30 101°5 
8 2 10 40 101°6 
10 Lege 10 50 101°9 
B. 
Treated after standing eight hours at ordinary temperature. 
2 8 10 10 09°7 
4 6 10 20 99:7 
6 4 10 30 101°3 
8 2 10 40 105°3 
10 ae 10 50 D7 
C. 
Treated after standing five days at ordinary temperature. 
2 8 10 LO 104 
4 6 10 DQ 121°6 
6 a 10 30 149°7 
& 2 10 40) 155°9 
10 SD 10 50 156°4 
1D) 
Treated after standing one and one-half hours at 80°-90° ©. 
2 8 10 10 101°3 
4 6 10 20 143°8 
6 4 10 30 135°9 
8 2 10 40 149°1 
10 Lys 10 50 155'3 


It is manifest from an inspection of Table I that the de- 
composition of the permanganate increases directly in each 
series of experiments with the increase in the proportion of 


304 Gooch and Danner— Points in the Interaction of 


sulphuric acid, that the amount of decomposition is greater as 
the time of action is extended, and that increase of tempera- 
ture heightens the change. We note in particular, for exam- 
ple, that the presence of ten per cent of [1:1] sulphuric acid 
induces at the ordinary temperature no immediate decomposi- 
tion of the permanganate, none in eight hours, and a breaking 
down amounting to four per cent in five days; and that the 
presence of fifty per cent of acid of the same strength ocea- 
sions the decomposition of about two per cent at once, fifteen 
per cent in eight honrs, and more than half the entire amount 
of permanganate in the course of five days. It is evident 
also that twenty per cent of the [1:1] acid produces no 
appreciable effect at ordinary temperatures and under expo- 
sures of a few hours only. The effect of heating the mixture 
of acid and permanganate to 80° C. for an hour and a half 
is closely-comparable with that brought about by the five days 
action at the ordinary temperature. 

In another series of similar experiments, the detailed record 
of which we omit as unnecessary, the absolute amounts of 
liquid and acid were increased while the proportion of the 
latter to the whole volume of the former was preserved. The 
volume of the liquid containing the acid and permanganate 
was fixed at 100 em* and the absolute amounts of acid were 
taken five times as great as those used at corresponding points 
of the preceding series. The amounts of decomposition ob- 
served in these experiments followed those of the first series 
so closely as to compel the conclusion that it is the proportion 
of acid present rather than the absolute amount which is 
chiefly influential in the decomposition of the permanganate 
under given conditions. In still another series of experiments 
which differed from the last in the single point that the 
amount of permanganate used was increased five-fold no appre- 
ciable differences in effect which might be traced to such 
extra use of permanganate were discoverable. 

It is, of course, possible, and even probable, that some 
decomposition of the permanganate by the sulphuric acid 
might be brought about after the addition of the oxalic acid 
during the warming of the mixture up to the temperature at 
which the oxalic acid and permanganate interact. The experi- 
ments of Table II were therefore undertaken to test this 
point. In them oxalic acid was replaced by a solution of fer- 
rous sulphate in order to secure the removal of the residual 
permanganate at ordinary temperatures. The greatest care 
was taken to guard against atmospheric oxidation during the 
course of the experiment. The solution of ferrous sulphate 
was standardized before and after making the test experiments 
and found to be unchanged during the period of work. In 


~ 


Potassium Permanganate and Sulphuric Acid. 305 


the first five experiments of series B the proportions of acid 
and liquid of series A were preserved while the absolute vol- 
umes were increased; in the last four experiments the range 
of variation in proportions was extended. 
TABLE II. 
Percentage of 


Percentage of | K.,Mn.O, used 
KeMn2Osin HeSO,q [1:1] as compared 


H.SO04 decinormal in solution with that required 
teal] Water. solution. during action. by theory. 
em? cm? em? 
A. 
Treated at once. 

2 8 10 10 100 

4 6 10 20 100°2 

6 4 10 30 100°1 

8 2 10 40 100°1 
10 ae 10 50 100°3 

B. 
Treated at once. 

10 80 10 10 100°1 
20 70 10 20 100°1 
30 60 10 30 100° 
40 50 10 40 100°5 
50 40 10 50 101°3 
60 30 10 60 103° 
70 20 10 70 “105° 
80 10 10 80 103°3 
90 2 10 90 108-1 


The results of these experiments indicate, as was antici- 
pated, that rather less decomposition of permanganate is 
caused by the sulphuric acid when the reduction of the re- 
sidual permanganate is effected at ordinary temperatures. The 
increase in the amount of decomposition as the proportions of 
sulphuric acid [1:1] present are pushed beyond fifty per cent 
of the liquid is striking. 

We have studied these same phenomena still further, vary- 
ing, however, the mode of proceeding so as to observe and 
measure the gas evolved from the liquid as Jones* and Brauner* 
did in their individual investigations of the evolution of oxy- 
gen during oxidations. In these experiments tubes of suitable 
size and length, holding from 100 em* to 200 em’*, were sealed 
at one end, filled completely with the mixtures of acid and 
permanganate, inverted, and allowed to stand with the lower 
and open end submerged in liquid of the exact composition of 
that which filled them. The details and results of these 
experiments are recorded in Table III. 


*loe. cit. 


306 Gooch and Danner— Points in the Interaction of 


TABLE III. 
iA. B. 
H.S0,[1: 1] = 50 per cent. H.SO,[1: 1] = 25 per cent. 
Time Gas from Gas from 
elapsed. 1¢0cm* Appearauce. 100 cm*. Appearance. 
5 min. 0‘'l em’ No change. Small bubble. No change. 
1) hour. (teiliger No change. | 
day taco hee Red brown. 
3 days. 153 “ Light brown. 9°6 em? { Reddish purple. 
Ae la los6n cs eh es { Turbid. 
iota Brown, turbid. sei Reddish pink. 
Saye 16 ‘“ {Clearing by precipi- Clearing by pre- 
) tation. cipitation. 
Dm ombaiel pou Clear, straw-colored. 18 “ Nearly clear. 
17 ‘ ] Wa ae zs (a3 ce 
353 00 Lp as ef of 18-4" S Clear and color- 
t less. 
C. Dion 
H.SO,[1: 1] = 12°5 per cent. H.SO,[1: 1] = 6°25 per cent. 
1 hour. Small bubble. No change. Small bubble. No change. 
l day. Bubble. ne H Bubble. us 
3 days. Bubble larger. iH a Bubble larger. ¥ ¢ 
Anos 71 em? Color lignter. Meme S e 
37 ce lei: iss ve ing 3 75 at (a3 
Ales eel) vee fe as Bre Little change. 


The full amount of permanganate present in 100 em* of 
each mixture should, if reduced to the lowest condition of oxi- 
dation, be capable of liberating about 28°6 cm* of oxygen, 
and every cubic centimeter of gas collected corresponds to 
3°5 per cent of the entire quantity of available oxygen. In 
comparing the amount of gas liberated at once by 50 per cent 
sulphuric acid [L:1] (Table III, A) with the amount of reduc- 
tion of the permanganate indicated under similar conditions 
(Table I, A) it appears that less than one-fifth (0°35 per cent) 
of the available oxygen of the permanganate which disap- 
pears in the action escapes solution and appears in free form. 
When, however, the comparison is made between the amount 
of gas liberated after four or five days (about 55 per cent of 
the total available oxygen) and the amount of reduction of 
the permanganate during a similar interval (Table I, C) the 
agreement is fairly close—within one or two per cent—the 
proportion of oxygen which goes to saturate the liquid being 
small relatively to the large absolute amount. It would seem 
to be evident that during this interval the breaking up of the 
permanganate resulted chiefly in its reduction to the lowest 
form of oxidation. After the seventh day in Exp. A, when 
a precipitate began to appear, comparatively little oxygen was 
set free; and on the thirty-fifth day, when the precipitation 
had ceased and the remaining liquid was straw-colored the 
amount of gas collected corresponded to about 61 per cent of 


Potassium Permanganate and Sulphuric Acid. 307 


the available oxygen of the permanganate. The remaining 
39 per cent must have gone with the precipitated oxide or 
have remained in solution as a higher sulphate. That but 
little of the higher sulphate did remain, however, is shown by 
comparison of A with B, in which after thirty-five days the 
liquid was entirely bleached. The gas finally set free in B 
amounted to 64:4 percent of the available oxygen of the 
permanganate, and the remainder, 35°6 per cent, would be 
enough to throw down about 90 per cent of the entire amount 
of manganese in the permanganate in the degree of oxidation 
of MnO,. It is noteworthy that the stronger acid, 50 per 
cent [1:1], still held some of the higher oxide in solution 
until the end, and that the acid of 25 per cent [1:1] allowed 
the decomposition to pass to completion in thirty-five days, 
while the smaller amounts of acid, 12°5 per cent [1:1] and 
6-25 per cent [1:1], brought about in forty-four days decom- 
position amounting respectively to 42 per cent and 17°5 per 
cent respectively. 


TABLE IV. 
Percentage Time elapsed. Percentage 
of — ee eee ee =— of K.Mn.20;, 


H.SO, [1:1] 1 day, 2 days, 3 days, 4 days, 5 days. decomposed. 


Oe Colony pel Colore lin Color Color Color 
unchanged. unchanged. unchanged. unchanged. unchanged. | 103°6 
Slight | Slight 9 | 
| sediment. | sediment. 
Slight 
| scum. | 
20 se a BL aes ea oan “ Color Color | 107-4 
| | junchanged. unchanged, | 
Slight Slight | 
sediment. | sediment. 
3 (er eq eins Cone aa act seviSy GR ES a Reddish Reddish 1069 
| tinge. tinge. 
Slight 
| sediment. | 
40 re bY f “ |Tinged with Reddish Reddish | 139-2 
| reddish |. brown. brown. 
| brown. 
50 e Hy i *“- | Reddish Reddish | Red | 157-4 
| | brown. brown. brown. | 
60 Color Color Reddish | Sherry Reddish | 158°9 
| redder. | redder. brown. brown. | olive. 
“70 uf o | oe ‘| Sherry | Reddish Reddish 161°1 


brown. | olive. olive. 


It seemed to be desirable in this connection to make the 
experiments detailed in Table IV, in which note is made of 
changes in color and formation of precipitates in 100 em* por- 
tions of liquid containing 10 cm* of decinormal permanganate 
and varying proportions of acid during five days’ standing, 


308 Gooch and Danner—Points in the Interaction of 


the degree of decomposition of the permanganate being finall 

determined, as in the experiments of Tables I and II, by add- 
ing a small excess of oxalic acid to those mixtures contained 
in ~ Erlenmeyer flasks, heating to about 80° C., and titrating 
with permanganate the residual oxalic acid. 

In the first five experiments little change of tint was noted 
upon the addition of the oxalic acid to the cold solution, but 
in the last two experiments the reddish olive color became at 
once distinctly red—presumably because the higher sulphate 
of manganese was attacked in the cold by the oxalic acid (as 
Brauner has shown) and so the natural color of the permanga- 
nate was permitted to assert itself. The extreme decomposi- 
tion—that which took place in the last experiment, in which 
70 per cent of the [1:1] acid was present—corresponds 
nearly to the reduction of the entire amount of permanganate 
present to the condition of oxidation of MnO, which is known 
to exist in combination with sulphuric acid in the form of a 
higher manganic sulphate. It is to be noted that the separa- 
tion of the insoluble higher oxide took place only when the 
percentage of acid was low. 

It appears therefore, in brief, that when potassium per- 
manganate and sulphuric acid are brought into solution 
together under the conditions which we. have studied there is 
developed a tendency toward reduction on the part of the 
former which is the greater as the strength of the acid is 
increased, as the temperature is raised, and as the duration of 
action is extended. It appears further, at least when the acid 
is not present in proportion greater than 50 per cent of the 
[1:1] mixture, that in the early stages of the action the oxygen 
lost to the permanganate is liberated, and that later on the 
decomposition of the permanganate results in the precipitation 
of manganese in the form of a higher oxide or in the reten- 
tion of the manganese in solution in ‘the form of a higher sul- 
phate... [itis natural to suppose that the first effect of the 
mutual action of the acid.and the permanganate is to set free 
permanganic acid, which, being unstable, breaks up with the 
results described. 

The bearing of these observations and inferences upon the 
question of the action of potassium permanganate during 
oxidations carried on in the presence of sulphuric acid is obvi- 
ous; for, if the aqueous acid is able to liberate permanganic 
acid in such proportions as to be spontaneously unstable, it is 
reasonable to presume that any reducing substance present at 
the time of such action may, by virtue of its attractive action 
upon the oxygen of many more molecules of the permanganic 
acid than would be necessary to supply the exact amount 
needed for perfect oxidation, tend to increase the general 


Potassium Permanganate and Sulphuric Acid. 309 


instability of the already unstable molecules and so set up a 
far-reaching decomposition. It seems to us that these consid- 
erations throw some light upon the phenomena observed by 
Brauner* in the oxidation of tellurous oxide in presence of 
sulphuric acid; and the fact that the liberation of free oxygen 
in this special case is more noticeable than in the oxidation of 
. ferrous salts or oxalic acid, for example, is explicable in the 
light of Brauner’s observation. that the attraction of tellurous 
oxide for oxygen is greatly inferior to that of these substances 
—not sufficient, in fact, to break up so unstable a substance as 
manganic sulphate, which is at once reduced by ferrous salts 
or oxalic acid. The practical lesson to be drawn is the desira- 
bility of keeping the acid present in oxidations effected by the 
agency of permanganate at the lowest limit consistent with 
perfect oxidation. 

In Table V are recorded the results of a comparison made 
between Brauner’s two excellent methods for the determina- 
tion of tellurous oxide by titration with potassium permanga- 
nate—the one in alkaline solution, the other in acid solution— 
in which the precaution suggested as to the restriction of the 
amount of acid which should be present was taken. The 
tellurous oxide used in these experiments was prepared for the 
so-called pure crystallized element by oxidation with nitric 
acid and the prepared and ignited oxide was dissolved in potas- 
sium hydroxide. 

In series A the alkaline solution of the oxide was diluted to 
100 cm’*, potassium permanganate was added in excess, sul- 
phurie acid [1:1] was introduced to an amount not exceeding 
by more than 5 cm* that needed for neutralization, oxalic acid 
was added in excess of the amount needed to destroy the man- 
ganic oxide and permanganate, the liquid was warmed to about 
80° C., and the surplus of oxalic acid was titrated by perman- 
ganate. 

In series B the alkaline solution of the oxide was treated 
with sulphuric acid [1:1] until the precipitate first thrown 
down was just redissolved, and 1 cm* of the same acid was 
added in excess. Permanganate was added in excess and oxalie 
acid in excess of the permanganate, the liquid was warmed, 
and titration by permanganate to the final reaction was com- 
pleted as usual. In the calculation of the results the atomic 
weight of tellurium used by Brauner in his work} was adopted 
and the figures obtained correspond fairly well (without the 
application of any correction) with theory based upon this 
assumption. Our purpose, however, was simply to test the 
agreement between titrations made in alkaline solution and 
those carried out in acid solution. 


_ * loc. cit. + loc. cit., p. 240. 


310 Gooch and Danner—Interaction of Potassium, ete. 


TABLE V. 
A. 
TeO. taken. TeO, found. Error. Mean error. 
(1) 0°1200 grm. 01199 grm. 0:0001 grim. — | 
(2) 0°0783 0:0783 0:0000 
(3) Os Site 00938 “ 070007, £9 eac-ts aan pee 
(4)" Vo1100 * " orlie “ “o-opie 7 CP RRaiEta ag 
(5) 0:0904 ‘ DANKO 00003 “ + | 
(6) ORNKOGS <5 OeloRng. .& DADO 9 + J 
B. 
TeO. taken. TeO. found. Error. Mean error. 


) 0:0910 eur 0°0912 grm. 0:°0002 grm. 
) 0°0910 00908 “ 0:0002 
3) 00911 * 070922 “¢ OOO ae 
4) O;09U3 aes: O;0913 0-0000 ‘ 
5) 
6) 


+1+ 


OO O;09 13% \° 0:;0001 ‘ 


| 
| 
00003 grm.-+- 
I 
| 
OHO PANE SOOM ES OOO = J 


+. 


The agreement between the indications of the two methods 
is evidently close, and it is suggestive that that error which is 
slightly the larger, and also in the direction indicative of larger 
expenditure of the permanganate in producing the effect 
sought, is found on the side of the determinations made in 
alkaline solution. 

As to the correlative question of the liberation of oxygen 
during oxidations by potassium permanganate in alkaline solu- 
tion we have made no experiments, but experience (not de- 
tailed in this paper) in the collection of the gas liberated in 
oxidations effected in presence of acid leads us to distrust the 
evidence of such experiments unless the amount of gas libe- 
rated is considerable. While, on the one hand, small quanti- 
ties of liberated gas may be so completely absorbed as not to 
appear free at all it often transpires, on the other hand, that 
the simple admixture of unlike liquids—such, for example, as 
a solution of potassium permanganate with sulphuric of 
strength insufficient to liberate oxygen—may bring about a 
very appreciable liberation of dissolved gases. So far as ap- 
pears, however, the affirmation of the liberation of oxygen in 
oxidations by potassium permanganate in alkaline solutions 
now rests upon evidence of that nature only. 


Penjield— Crystallography of Cesium-Mercury Hulides. 311 


Art. XL.—On the Crystallography of the Casiwm-Mer- 
curic Halides; by S. L. PENFIELD. 


THE salts to be described in this paper were prepared by 
Prof. H. L. Wells, and their chemical description has been 
- given by him in the September number of this Journal. 

The crystals were all measured on a Fuess reflecting goni- 
ometer, model II, ard great pains were taken to select the best 
measurements as fundamental. In a few cases, where the 
erystals were very small and the reflections of the signal, 
therefore, rather broad, the mean of a series of measurements 
was used. The axial ratios are given in tabular form at the 
beginning of each separate chemical type and the fundamental 
angles, from which these are derived, are marked by an 
asterisk in the table of angles accompanying each salt. 


Type ses1. 
Chea Oat aaC 

Cs;HgCl;, Orthorhombic, monoclinic hemihedrism 0°7976: 1: 0°6605 
Cs3;HgC1, Bre. at e a 0 7882: 1: 0°6527 
Cs;HgBr; i + H 0°7966: 1: 0°6656 
CssHgI;, Orthorhombic, sphenoidal hemihedrism 0°5362:1:0°97975 

or 2 a@:b:%c = 0°8043:1: 0°6532 
Cs;HgBrsI. of S ‘approximately like CssHel; 

The first three salts have ex- ; i 


actly tle same habit and erystal- 
lize in slender prisms, attached at 
one end and terminated at the ee 
other by faces which are arranged 
with monoclinic symmetry, figs. 1, 


2and 3. ‘The crystals were sel- 
dom over 1™™ in diameter, but the m 
faces were perfect and admitted 
of accurate measurement. The 
forms and angles are: 
Fl MILO-e AE ah ADI a: “ile joe soa 
a <OLl, Lv €, O21, 2-% fi Wali Al 
Cs3HegCl,; Cs3;HgCl, Bry Cs;HgBr; 
Z: Measured. Calculated. Measured. Calculated. Measured. Calculated. 
mam, 1104110 = *17° 9! 651336011169) 307 *TTS 5 
map, 110.111 = *43 21 *43° 29 ¥43 64 
map, 110,111 = 80 41 80° 413’ 8037 80° 363’ 
Ad, WOO —= 6955-69) 54 70 14 «70 13 69 49 69 48 
mane, 110,021= 60 8 60 11 6010 60 7 
dx¢, 011,021= 19 29 19 26 19 28 19 25 
dvd’ O11, 011= 66 53 66 534 *66 16 6716 67 18 
dap, O1lA111= 34 39 34 39 34 37 384 44 3447 34 49 


Am. Jour. Sci.—TuHirD Series, VoL. XLIV, No. 262.—OctopEr, 1892. 
21 


é 


312 Penfield—Crystallography of Cwesium-Mercury Halides. 


The crystals have orthorhombic optical properties. When 
lying on their prismatic faces all show in polarized light an ex- 
tinction parallel to the vertical axis, and in convergent light a 
trace of the ring system can be seen, indicating that the plane 
of the optical axes is the base. 

We have here an excellent illustration of monoclinic hemi- 
hedrism in the orthorhombic system. Among all of the erys- 
tals which were examined, there was not one which had a holo- 
hedral termination. The forms @’ and p', when present, were 
always smaller than tne corresponding forms d and p, while e 
was only observed to the right above. Also the right handed 
vertical edge of the prism showed a tendency toward a skeleton- 
like growth, which was not observed to the left. In measuring 
the crystals great pains were taken to detect a monoclinie char- 
acter by the angles, but none could be found. Of course the 
three. salts may be regarded as monoclinic, with an angle £, 
differing so little from 90° that it can not be detected by the 
goniometer, but against such a supposition are the arguments, 
that the crystals have orthorhombic optical properties and, 
while there is a variation in the axial ratios of the series as 
bromine is substituted for chlorine, there is no change in the 
angle #, as would be expected if the salts were monoclinic. 
In this connection it is interesting to note that while the chlo- 
ride and bromide are very similar in their axial ratios, the 
chemically intermediate chloro-bromide is not erystallographi- 
cally intermediate. 

At the present time there seems to be no other known com- 
pound which illustrates this hemihedrism. Different substances, 
which have been referred to this class, as datolite or wolfra- 
mite, for example, have been shown by accurate measurement, 
or a study of their optical properties, to be truly monoelinie. 
Professor P. Groth, in the last edition of his Physikalische 
Krystallographie, has not mentioned this hemihedrism as a pos- 
sibility in the orthorhombic system, although in the former 
edition of his work and in most treatises on crystallography it 
is recognized. 

4. 


Penfield—Crystallography of Cesiwm-Mercury Halides. 318 


The different crops of Cs, HgI, which were examined showed 
a great variety in habit, represented by figs. 4-8. The hemi- 
hedral development is not always strongly marked, and forms 
like figs. 5 and 6 are the commonest. The crystals sometimes 
measured over 5™™ in diameter and gave excellent reflections. 

Only one crop of Cs,HgBr,I, was examined. The crystals 
- were in the form of sphenoids, fig. 9, some of them over 10™™ 
in diameter, but the faces were curved and striated and only 
approximate measurements could be made. 

The forms which were observed are: 


BONO, GS oh TO, SG OOP Fae, TT ey Sse 


c, 001, 0 v, O11, 1-% yoy Wal at 0, 112, 4 @ 121% Hay 
The angles of Cs,HglI, are: 
Measured. Calculated. Measured. Calculated. 

cao, OO1LA 112 = AG? NY AGaam 2a 
CAD. ONO IL ze, SCI as SOGYES GI 0A0%, 112.112 = 39 55 39 46 
peal tl —*50 23 000, ND Za I Sst Bet 87 56 
Cnr 0x Oi 44523 Ad? 25! On dV. M02 1950 11S) 5553 
cas, 0014021 = 62 58 62 58 pae, LE a, Slee aS Le 74: 


Both Os,HgI, and Cs,HeBr,I, cleave distinctly, parallel to 
the base, but the crystals are very brittle and usually break 
with a conchoidal fracture. Crystals of the former, which are 
tabular parallel to the base, show in convergent polarized light 
a bisectrix normal to ¢, 001; the plane of the optical axes is 
the macro-pinacoid and their divergence is large. 


Type 2: 1. 
2 W'S C 
Cs.HgCl, not measured. 
Cs,.HgBr, Orthorhombic 0°5706:1:1°4715 


CseHgCloBre ub SAG Be ale es 

Cs2.HgClele a not measured. 

CseHel, Monoclinie 1°3155: 1: 0°9260 Bi="69) 564 
Cs.HgBrole Approximately like Cs,.Hel, 


The crystals of Cs, 1gCl, were too thin to measure. 

Both Cs,Hgbr, and Os, HeCl _Br, crystallize in thin rectangu- 
lar plates; those of the former were sometimes several centi- 
meters long, but seldom over $™ thick, and had the 10, 
habit shown in fig. 10. The crystals of ‘the latter salt 2D 
were very much thinner.. The plates were often Li 
grouped, with the large pinacoid faces slightly diver- 
gent, and isolated crystals, suitable for exact measure- 
ment were only occasionally found. 

The forms which were observed on Cs,HgBr, are 


PeOlOniG ac 00l Ones 10h eed OUI lt 0p. 122 1h eee |\77 


and on Cs,HgCl;Br,, 6, m and a second prism LOU, 1-3. The 
end faces could not be made out. 


814 Penjfield—Crystallography of Cesium- Mercury Halides. 


The angles of Cs,He¢Br, are: 


4 Measured. Measured. Calculated. 
mam, 110,110 =*59° 257 map, 110 . 221 = 33° 584’ 33° 587 
ONG: 2010) O34 12 


On this salt the dome d is always small and frequently want- 
ing. The pyramid p was only observed on a few crystals. In 
convergent polarized light a bisectrix may be seen normal to 
6,010. The plane of the optical axes is the macro-pinacoid 
and their divergence is so large that they cannot be measured 
in air but in amonobromnaphtaline the following values were 
obtained : 


2H = 80° 127 for yellow, Na flame. 
2H = 85 23 for red, Li flame. 


The dispersion is strong p>v. The acute bisectrix is axis 
of least elasticity, the double refraction is therefore positive. 
The only angles on Cs,HgCl,Br, which were measured are : 


mam, 110.110 = *59° 6’ and 110 «130 = approx. 30° 53’, calculated 30° 597 


In convergent polarized light a bisectrix may be seen normal 
to 6, 010. The plane of the optical axes is the macropinacoid, 
and their divergence is large. The axis of greatest elasticity 
is normal to 6. 

Only very fine needles of Cs,HgCl,1, were obtained, which 
were too small for measurement. These appeared under the 
microscope as striated prisms, with their obtuse edges rounded 
by oscillatory combinations. In polarized light they show a 
parallel extinction and in convergent light a biaxial interfer- 
ence figure, the plane of the optical axes being the vertical 
pinacoid. ‘The acute bisectrix is axis of least elasticity. 

The erystals of Cs, Hel,, which were frequently several cen- 


18}. 


es 


14. timeters in diameter, showed a variety of 

\ habits represented in figs. 11, 12 and 13. The 

oe \. erystals of the latter habit are usually attached 

IN at one end and taper toward the free extrem- 

pees | ity, owing to a tendency to develop vicinal 
\m | m pyramids in the zone d—0. 

ie The erystals of Cs,HgBr,I,, which were 


examined, were about 2™™ in diameter and had 


Penfield— Crystallography of Cesium-Mercury Halides. 315 


the simple habit shown in fig. 14. The faces were rounded 
and uneven so that only approximate measurements could be 
made. 

The forms and angles are: 


a, 100, #2 c, 001, O d, 201, 2-2 
b, 010, @-2 m, 110, I e, O11, 1-2 
Cs.Hel, Cs2He Brel, 
Measured. Calculated. Measured approximately. 

cad, 001, 100 = 69) mi DOM 66° 41’ to 66° 477 
Mirms LOA TN0) == 11158 a) GPO mile 25 t 
OG ACh MOO APO ay a 
Care 10.01 104005. ANU? AY 


The cleavage of both salts is perfect parallel to the base, 
less so parallel to the clinopinacoid. With Cs,HgI, the plane 
of the optical axesisat right angles to the symmetry plane and 
clinopinacoid cleavage sections show in convergent polarized 
light an obtuse bisectrix, which is axis of least elasticity. The 
axis of greatest elasticity makes an angle of about 50° with 
the vertical axis in the acute angle /. 


LEGO ah oul. 
GSeiors C 
CsHgCl, Isometric and Orthorhombic 0°57735: 1: 0°40884 
OsHgClBr. Pe i it approximately like the above. 
CsHgBrs fe ‘* Monoclinic MONZA Me OKO tdloee Gi tS leenlic 
CsHgBrl, u 0978 :1:0°743 , B= 87° 32” 


CsHegl, not measured. 


The first three compounds are dimorphous and, from solu- 
tions containing an excess of alkali halide, they all crystallize 
in cubes. These sometimes have their edges truncated by 
small dodecahedron taces, less often beveled by 210, 7-2. The 
erystals show a slight action on polarized light and give an ex- 
tinction parallel to the diagonals of the cube, but this anomaly 
is probably due to some internal tension, for when crushed 
the fragments are isotropic. No cleavage could be detected. 

CsHgCl, was repeatedly recrystallized from water and 
always two types were observed. One of these was confined 
to those crystals which were attached to the sides of the beaker, 
while those which grew 
more in the interior had 
an entirely different habit. 
The crystals of the first 
type averaged about 2™™ 
in greatest diameter and 
had the habit shown in figs. 15 and 16. The forms and angles 
are as follows: 


316 Penfield—Crystallography of Cesium-Mereury Halides. 


a, 100, 7-7 TALEO eel e, 101, 1-7 d, 021, 2-% 
b, 010, @-% n, 130, 7-3 ROO, ip, lililecat 
Measured... Calculated. ~ Measured. Calculated. 
mam,110%110= *60° 07 @ ap, 100.111 =56° 45’ 56° 4547 
@ xd, 021 . 021 = *101 274 Map. 110,111=71 334 1 33 
p ap, lILalll= 66 284 66° 297 p ad, LILA 021 = 36 54 36 54 
Dp xp, LILA = 36154 36 54 aaeé, 100,101=54 424 54 42 


map, 1104111 50 433 50 433 a af, 100,201=35 13 35 134 

The erystals were brilliant and gave wonderful reflections. 
The prismatic angle was measured repeatedly and found to - 
be 60° and the forms could be referred to the hexagonal sys- — 
tem, making the m and 6 faces a prism of the first order, a 
and m a prism of the second order and p and d the unit pyra- 
mid. There was nothing, however, in the development of the 
faces to suggest hexagonal symmetry. Thin sections were 
prepared, hoping that the optical properties would throw some 
light upon the form, but they showed only a very weak 
double refraction, in fact they appeared almost like isotropic 
sections, so that no satisfactory conclusions could be drawn. 

The crystals of the second type were spear-head shaped, fig. 
17, and grew out into the center of the solution, either attached 
to one another by the acute solid angles, or to a slender, paral- 
lel growth of crystals, which served as a sort of stem. The 
erystals which are about 5™" in length are complicated and per- — 
plexing, and the faces are developed with triclinic symmetry, 
although they can be referred to the axes of the first type. 
The most prominent faces are shown in the figure, while the 
distribution of all those which gave distinct reflections are 
given in the spherical projection, fig. 18. The forms which 
were observed are given as if they belonged to a triclinic erys- 
tal and are: 


ow’, 1151, 15-15 


Penfield— Crystallography of Cesium-Mercury Halides. 317 


The erystals gave excellent reflections and only occasionally 
a slight striation interfered with making accurate measure- 
ments. All of the forms were observed on two erystals and 
probably others could have been found by measuring a larger 
number. 

The erystals of CsHgClBr, have a similar habit, fig. 19, and 
- the distribution of all of the faces which gave distinct reflec- 
tions is given in the spherical projection, fig. 20. This salt is 
more insoluble than the chloride and the crystals are conse- 
quently much smaller, not over 13™™ in greatest diameter. 
All of the forms given above for the chloride were observed 
except z and ¥, and in addition: 


GE Pa, Oa aa a 7’, 131, 3-3, hy Mel Mate t, 2127, 142-6 


The crystals gave very good reflections, considering their 
size, and the best measurements agreed so-well with those of: 
the chloride that no attempt was made to calculate a new axial 
ratio. The most marked difference in the two salts is the 
development of the zone p” 2” q'” 7’” in the chloride and 7” 
d’ t'” g’" p’” fF in the chlorobromide. ' 

The measured and calculated angles are as follows: 


CsHgCls OsHgClBre Calculated. 
Ming fee MOS 201 44° 45/7 45° 67 44° 58) 
AD a 20lene 11) 26 35 26027 26 344 
Dp 7d; Wika Ney Sie id 18 34 18 27 
ed, Sela 021 18 26 18 23 18. 27 
Gh Ais © 2 Oe TES 26 44 26 26 26 344 
Lenina ols 131 33 40 33 20 33 404 
enh we LON 13 1 26 364 2602 26 33 
WD TG IAS Ue 21 35 21 474 
P= ee Mase aU 26 33 26 37 26 344 
Deer eDiy EI LI 36 524 367.377 36 54 
Dee tO LO et oa 44 44 44 58 
Yo Mie ak ODA 132 2218 22S 
Bo gfe coe Mees 28 38 28 35 
(genie isa lls} 50 54 50 49 
DO RO AD Ree) 62 294 6222s 62 284 
foe Ore UML TIES 60 46 60 45 
Dee Veale «113 66 53 66 59 
aie ee ie 26 38 26 344 
IY AO, NN NB? 18) 23 Ne) eh 
Wee Opn etal 3 2.00402) 18 34 18 27 
COAG, 2121 x 02) - WO 1183 10 19 
Genie = 132. 191 50 59 AOE et 50 46 
Gi Dips We sl 50 50 50 49 
Gir oop eed play Sp) Ey) 60 3 60 4 


It will be seen from the spherical projection that the forms 
of CsHgClBr, lie mostly in three zones, suggestive of hexag- 
onal rhombohedral symmetry, although there is nothing in 
the arrangement of the faces, and still less with CsHgCl,, to 
indicate that this is correct. The crystals of CsHgCIBr, have 


, 


318 Penfield—Crystallography of Cesium-Mercury Halides. 


a slightly stronger action on polarized light than those of 
CsHgCl,. When lying on the large g faces, both show an 
extinction parallel to the edges between p, g and d. 

On a crystal of CsHgCl, the faces in the zone p, qg, d, 7 
made prisms, which served for the determination of the follow- 
indices of refraction. 


od 
‘ 


Prism of 36° 54’, 021 , 111, n, y, Na flame 


): 111, = Il n, 7, Li flame = 1-779 
PrismmOn Goa 2Sd.nlS lan Wl wine a ere pede — ela : 


1 
) Nip kt tet EEO, 


The crystal was of course very small and the refracted rays 
were not very bright, but the latter were well defined and 
the double refraction was not strong enough to separate them 
into two distinct rays. 

The author cannot give any satisfactory explanation of these 
curious forms. They seem to illustrate a tetartohedral devel- 
‘opment of the faces of an orthorhombie crystal, resulting in a 
figure with triclinic symmetry. The mathematical relations 
have been very carefully determined and the facts given. It 
is hoped that a further study will throw some light on the 
subject. 

The different crops of CsHgBr, which were examined 
showed a variety of habits, represented by figs. 21, 22 and 28. 


21. 22. 23. 
i 


V, z 3 
| 


™m 7m 


| 
| ‘ 


The forms and angles are as follows : 


c, 001, 0 é, 201, — 2-7 oveleleleeal y, 261, — 6-3 
m, 110, I a, UO Mes, p, 221, — 2 ape MS S=83 
Measured. Calculated. Z Measured. Calculated. 
cam. 001 4110 = *87° 582’ mam, 110.110 =*90° 387 


o8 
cand, 001 ~ 101 = *35 52 Oa LOMA 131= 60 41 60° 40 
Cee OOICN 2 Oley ard 284 52° 303’ e ap, 201,221= 38 46 38 464 
cao, OOLAlIL= 45 40 45 49 ap AN eerie Of Ak Of Be 


The crystals are seldom over 5™” in diameter and sometimes 
have a hemimorphie development, although this is not always 
apparent. In the prevailing type, fig. 22, there is perhaps a 
tendency for 221 to predominate over 221 but this is not 
great. The pyramids # and y were observed only with hemi- 
morphic development, fig. 23. The crystals were tested for 
pyro-electricity but no satisfactory results were obtained, 


Penjield—Crystallography of Cesium-Mercury Halides. 319 
which is perhaps owing to their small size. 24, 

The crystals of CsHgBrI, were about 2™™ 

in diameter and had the habit shown in fig. oe 
24, which is quite different from that of the 
bromide. The forms and angles are as follows: 


b, 010, i? c, 001, 0 1, 320, 7-3 s, 034, 3-7 
Measured. : Measured. Calculated. 
He Uf 320 ~ 320 = *66° 8’ LAS, 320 ~ 034 ee (0) 
bas, 010 4 034 = *60 54 las, 320.034 = 76 16 76° 50’ 


The basal planes were curved and uneven so that no satis- 
factory measurements could be made from them, and the 
other faces, although bright, did not give very satisfactory 
reflections. The crystals show in convergent polarized light 
an optical axis, almost normal to the base, the plane of the 
optical axes being the clinopinacoid. 


Type 2:3. 
GIS OE 0 
Cs,HgsI;. Monoclinic, hemihedral. 0°3438: 1: 0°3544, 8 = 71° 554! 
26. 


The crystals of this salt have a curious development. 
Some of the most conspicuous forms are triangular plates, fig. 
25, while fig. 26 is a projection of the same upon the clino- 
pinacoid. These crystals are terminated above by a_ basal 
plane and below by pyramidal faces, which gives a curious 
hemimorphie development in the ‘direction of the sym- 
metry plane. A variety of habits was observed, long pris- 
matic, skeleton forms and simple shapes like fig. 27, but in ° 
almost all of these the hemihedral character was prominent. 
The crystals frequently measured over 10™ in greatest diam- 
eter. The faces were bright and gave excellent reflections. 
The forms and angles are as follows : 


b, 010, a2 c, 001, 0 m, 110, I p, 111, 1 


The pyramid was observed only with hemihedral develop- 
ment. 
Measured. i Measured. Calculated. 
Cen, 00x LUO “ae oly: map, 110 > 111 = *50° 267 
MxM, 110 110 =*36, 12 D Ap Ol Orley TAN It) ume (ene: 


320 Penjfield—Crystallography of Cesium-Mercury Halides. 


Two cleavages were observed, one perfect parallel to the 
clinopinacoid, a second less perfect parallel to the base. In 
polarized light clinopinacoid tables give an extinction, inclined 
about. 28° to the vertical axis in the acute angle 8. Basal 
plates show in convergent light an optical axis not far removed 
from the center of the field. The plane of the optical axes is 
the clinopinacoid. 

These crystals furnish an excellent illustration of inclined 
faced hemihedrism, as recently developed by Prof. Geo. H. 
Williams,* who has shown that it is of frequent occurrence 
on pyroxene. 

Type 1: 2. 

Gp eUeeae 

CsHg.Cl;, | Monoclinic 16099: 332, 

CsHg.ClBr, Orthorhombic 0°586 : 

CsHgsBr; ce 0590 : 
CsHgels, not measured. 


ee 
' 


CsHg,Cl, was made in slender lath-shaped crystals, over 
10™" long in the 
direction of the 
symmetry axis 
but not over $™™ 
in diameter. 
Fig. 28 repre- 
sents a simple, and 29 a twin crystal, with the orthopinacoid 
as twinning plane. The forms and angles are as follows: 
a, 100, #7 c, 001, O d, 011, 1-2 
i-t m, 110, L p, 111, —1 
Two orthodomes were also identified, 101,and 201, but they 
were very small and yielded only approximate measurements. 


28. 29. 


Measured. Measured. Calculated. 
aac, 1002001 = *78° 54’ ce am, 001,710 = 84° 5’ 84° 5’ 
aam, 100,110 =*57 40 map, 110,111 = 21 12 31 8 
oO wh MN AOE Stan ye Sill Gap, 100,111 =58 4 5Sae 


bap, 0104111=47 19 47 19 


The plane of the optical axes is at right angles to the sym- 
39, metry plane and the obtuse bisectrix is nearly normal 
“,, to the base. 
© | Both CsHg,ClBr, and CsHgBr, were made in 
rectangular tablets, fig. 30, which were not over 
13°". in greatest diameter and were very thin. _ Twins 
were common, with the unit prism as twinning 
l| plane, and the plates often penetrated at angles of 
about 60° and 120°, reminding one of little cerussite 


Le twins. 


* This Journal, xxxviii, p. 115, 1889. 


Penjield—Crystallography of Cesium-Mercury Halides. 321 


The forms and angles are as follows: 


JsHe.ClBr, CsHg.Br; 
bs ONO, Ge b, 010, 7-7 
m, 110, £ nm, 120, 2-2 
d, 011, 1-% d, 011, 7-% 
e, 014, 4-% 
Measured. Calculated. Measured. Calculated. 
m xm, 110.110 = *60° 44' Dy Tyypun!: i s SAIL BY 


De oneniywinge == 05602 35,00 60244) OC Bid) s01 0/0) == ©4210 
Om O10 W120 = 40 20) "40a 
bre, 010,014= 73 25 73 57 


Type 1:5. 
Gh 2 Dee Me 
CsHg;Clii, Monoclinic 0°7233: 1: 0°4675 = 85° 51’ 40" 
CsHg;ClBrio Toate Os Tully le O;4 5 Glaus Oy —==08 529 


The chloride was made in prismatic crystals, fully 
10" long, and having the habit shown in fig. 31. 
The forms and angles are as follows: 


ee at a d, 011, 1-2 e, 101, 1-2 f, 101, —1-7 


The dome f was usually wanting. 


Measured. Calculated. Measured. Calculated. 
Mn VOrx LO 0 3h MAGe MLO OU =e Siu dees 
deOOLl AO 50) 0 Mend, LOOMS; 498 e848 
M x e, 110.101 = *66 8 Gey AON AONI=33 983.0 39 294 
ane OU 2 OW = 41 21 41° 204’ ée af, 101,101=65 43 65 42 


The chlorobromide CsHg,ClBr,, is much 
more insoluble than the chloride and was 
made in crystals, which were not over $™ 
in greatest diameter. The habit is shown 
in fig. 82 and is very different from that of 
the chloride. The forms and angles are as follows: 


m, 110, I d, 011, 1-4 e, 101, 1-7 
ui Measured. e Measured. Calculated. 
mam, TOPO se 40’ d xe, O11 2101 = *40° 58’ 
Onn; Osta A Oe och ay Mi Ad, OOM 2340) ome Oe 


The erystals are strongly double refracting and the little 
tables show in convergent polarized light a bisectrix nearly 
normal to ¢. The plane of the optical axes is the clinopina- 
coid and the optical axial angle is small. The interference 
phenomena are very interesting when observed through colored 
glasses. In the hyperbola position the figure is almost uni- 
axial when viewed through red glass, while with blue the 
hyperbole are separated, probably as much as 15°-20°. 


Sheffield Scientific School, New Haven, June, 1891. 


322 M. C. Lea—Silver Hemisulphate. 


Art. XLI—On Silver Hemisulphate; by M. Carry Lma. 


THE existence of those substances which I described some 
years ago under the name of photosalts of silver* necessarily 
implied the existence of the hemihaloids of silver also, as 
these latter entered into the composition of the photosalts. 
Similar inferences, though less definite, had long been drawn 
from the action of light on silver haloids. ‘Two of these, the 
chloride and bromide, lost by the action of light their com- 
plete solubility in ammonia without becoming completely sol- 
_uble in nitrie acid. Evidently there was indicated an inter- 
mediate compound between the normal haloid and metallic 
silver. During the last ten or twelve years I have devoted 
much time to the attempt to isolate these lower compounds of 
silver and to gain some certain knowledge as to the hemioxide, 
whose existence seemed almost a necessary inference from that 
of the hemihaloids. Some eight years ago, I obtained a sub- 
stance having all the properties which one would be disposed 
to ascribe to Ag,Cl and a large number of analyses made 
seemed to confirm the view. I hesitated, however, to publish 
a description of it, not feeling entire certainty that it might 
not be a mixture, as to which a concordance of the proportions 
found of Ag and Cl with theory gives no sufficient informa- 
tion. Since then M. Guntz has described a subchloride ob- 
tained by acting on silver hemifluoride with phosphorus penta- 
chloride and a hemioxide derived from it. Up to the present 
time no combination of silver hemioxide with an oxyaene has 
been known. 

Such a combination I have been able to obtain as a double 
salt of hemisulphate and normal sulphate containing one mole- 
cule of each. The new salt has a light bright brown color, and 
exhibits a stability which in view of its composition, is some- 
thing remarkable. It has no tendency either to oxidation or 
to reduction. Nitric acid, unless very strong, has but little 
action upon it. Acid of 1:42 poured over it in large excess 
and let stand for several days gradually dissolves it completely, 
but the same acid diluted with with two or three times its vol- 
ume of water has so little action that it forms a convenient 
means of purification. On the other hand, ferrous sulphate 
which instantly reduces argentic sulphate has no action what- 
ever on the new substance even with several days’ contact. 
Hot strong sulphurie acid has no action. It might almost be 
expected that under its influence, the argentous salt would 
gradually take up oxygen and be converted into argentic sul- 


* This Journal, xxxiii, May and June, 1887. 


M. C. Lea—Silver Hemisulphate. 323 


phate. But a specimen which was covered with a large excess 
of undiluted sulphuric acid in a flask and was kept under boil- 
ing water for ten hours was not altered thereby. Another 
strong proof of its stability is found in its resistance to heat. 

The application of heat produces a somewhat curious suc- 
cession of colors. The terra cotta or warm brown shade of 
the moist substance changes by drying above 100° to pale 
lilac, at 165°-170° it becomes grayish, at a somewhat higher 
temperature, yellowish green. Considerably below red heat it 
acquires a fine ruby red color. In cooling, this red darkens 
almost to black, then becomes lighter again and when cold the 
color is light olive-green. The changes are repeated as often 
as the substance is heated and cooled. No sulphuric acid 
vapors are disengaged even at a low red heat. 


It was mentioned in a previous paper that when silver 
nitrate is reduced by solutions of phosphorous or hypophos- 
phorous acid or by acidified solutions of their alkaline salts, 
transient colorations were produced that seemed to suggest the 
presence of some form of allotropic silver. Since that paper 
was published this reaction has been taken up for further 
study. It soon appeared that when the silver salt was treated 
with a solution of alkaline hypophosphite, acidified with sul- 
phuric acid, the result obtained was entirely different from 
that which presented itself under any other circumstances. 
It became clear that sulphuric acid did not act solely by setting 
free the hypophosphorous acid, but also acted on the silver 
with formation of a double sulphate. 

A remarkable though limited analogy here presents itself 
between the substance just described and the photosalts of 
silver. The silver hemihaloids are very unstable substances, 
but acquire stability by uniting with the normal haloids. In 
the same way the hemisulphate, which is not known to be 
capable of separate existence, becomes perfectly stable by 
union with the normal sulphate. The limitation to this 
analogy lies in the fact that the last mentioned combination 
occurs in definite proportions, which does not seem to be the 
case with the halogen compounds. 

The new substance then is formed by the joint action of 
sulphuric and hypophosphorous acid on a silver salt. Hypo- 
phosphorous acid has but little action on silver sulphate 
already precipitated, but it is different when the silver sulphate 
is formed in presence of hypophosphorous acid. 

Several silver salts may be used. I have at different times 
employed the nitrate, phosphate and carbonate. The latter is 
perhaps the best, because the action with the nitrate is too 
rapid, and with the phosphate, too slow, and for other reasons. 


324 M. C. Lea—Silver Hemisulphate. 


A weighed quantity of silver nitrate is precipitated with an 
excess of alkaline carbonate and washed. The carbonate, as 
well as all the other reagents employed must be absolutely free 
from chlorides, otherwise the product becomes contaminated 
with silver chloride which cannot be removed. The silver 
carbonate is then treated with a solution of alkaline hypophos- 
phite acidified with sulphuric acid. All the alkaline hypo- 
phosphite of commerce contains much more than a trace of 
chloride: this is best got rid of by adding to its solution a 
little solution of silver nitrate, stirring well at intervals, letting 
stand for twenty-four hours and filterimg. This filtrate with 
addition of sulphuric acid is to be poured over the moist silver 
carbonate and constantly stirred. The reaction is complete in 
twenty or twenty-five minutes, when a bluish-black film of 
reduced silver begins to form on the surface. Further ac- 
tion is then cut short by neutralizing the liquid with alkaline 
carbonate. The precipitate is next to be washed several times 
by decantation. Very pure distilled water is, of course, needed 
throughout. 

Convenient proportions are: 40 grams silver nitrate pre- 
cipitated with excess of alkaline carbonate. Of sodium hypo- 
phosphite, 100 grams, dissolved in 650 ¢ ¢. of water are 
treated with a little silver nitrate, and after standing and filter- 
ing, 4 ¢. ¢. of sulphuric acid are to be added and the liquid 
poured over the silver carbonate. After a few minutes, 6 e. e. 
more of sulphuric acid, diluted with a little water, are added 
by degrees. With this second quantity of sulphuric acid the 
characteristic reddish-brown color of the substance first ap- 

ears. 

: This process may be varied by precipitating with disodic 
phosphate (which must be perfectly free from chloride) instead 
of alkaline carbonate. The action is much slower, about 24 
hours being needed. Silver nitrate itself may be used, but 
the action is too rapid and the product is less in quantity. 

The crude product obtained in either way is to be purified 
with nitric acid. Acid of 1:42 is diluted with three times its 
volume of water, and of this dilute acid a quantity is taken 
about double in volume to that of the precipitate and of the 
water left after decanting closely. After a time some efferves- 
cence takes place, but the mixture does not become warm. 
After standing for three or four hours over the precipitate, it 
is to be poured off and the precipitate washed. ‘This treat- 
ment with acid is applied three times: the first removes a good 
deal of silver, the second a little, the third a trace. Each time 
the acid is left three or four hours in contact. The product is 
then washed by pouring on it a large quantity of boiling 
water. This is repeated four or five times, each time (except 


M. C. Lea—Silver Hemisulphate. 325 


the first) placing the vessel in a water bath kept at 100° C. for 
several hours. 

The product is either dried in the air or (for analysis) at 
100° C. It forms a bright brown substance, permanent in the 
air, changing to violet when kept for some time at 160° C. 
It has the peculiarity that when water is poured on it, it makes 
a sharp hissing noise. This takes place with the air- dried sub- 
stance as well as that dried at higher temperatures and as much 
with the former as with the latter. 

The substance after purification has about one-half the 
weight of the silver nitrate taken. 

These proportions and this mode of operating are those that 
I have found to give the. best result. But the substance is 
formed under a great variety of conditions. It seems impos- 
sible to bring a silver salt into contact with alkaline hypophos- 
phite acidified with sulphuric acid without producing more or 
less of it. Its presence is often completely obscured by re- 
dueed silver. But a mass which looks perfectly black and 
might be supposed to contain nothing but metallic silver will 
leave, when treated with nitric acid, a bright brown residue of 
the double sulphate. We have here, as before, an analogy 
with the photosalts. For it will often happen that a blackish 
mass, containing metallic silver and mixed or combined silver 
chlorides will, when treated with nitric acid, resolve itself 
into bright purple or rose colored photochloride. 

All the specimens of this new substance contain a little 
phosphoric acid which cannot be removed. Reckoned as 
phosphoric anhydride it amounts to a little over two per cent. 
Three determinations gave respectively, 2°30; 2:09; 2: 18, mean 
ZAG. 

It is apparently united with silver and this silver phosphate . 
is united so firmly with the double sulphate that it cannot be 
detached. If it were not so united it would be dissolved in 
the nitric acid with which the substance is three times treated 
if it were normal phosphate, and if it were hemiphosphate it 
would be converted (if in a free state) to normal phosphate 
and dissolved. 

Another attempt to remove this phosphate was made by 
heating the substance with sulphuric acid to 100° C. for ten 
hours, followed by copious treatment with boiling distilled 
water to wash out the sulphate which it was hoped would be 
formed at the expense of the phosphate. It seems difficult to 
believe that a silver phosphate could resist this treatment, but 
a quantitative determination showed that the proportion of 
phosphoric anhydride is not even diminished by it. 

Other modes of formation than those described here were 
experimented on with the view of obtaining the substance 
free from phosphate, but without good result. 


326 M. C. Lea—Silver Hemisulphate. 


It is possible that the silver phosphate may be combined in 
definite proportions and the approach to uniformity of com- 
position somewhat favors this idea. But such a view would 
require the assumption of a large, perhaps too large a molecule. 


Analyses, 


A. Material prepared from silver carbonate and dried at 
100° C. 


(1) (2) Mean 

Deiat Siete 76°13 76°75 76°44 
ORE EERIENG 3°29 bik 3°29 
P,O Ree ais 90) 09 2°19 
SO, foley ere 16°19 16°47 16°33 
Water _.-.- 1:78 4 1°78 
99°69 100°03 


B. Material prepared by various other methods considered 
less reliable. 


Determinations. 


Ag per cent. ReOr. SOs. O. 
78°59 3°93 
78-45 3°69 
TRON 3°61 
75°43 2°18 15°61 3°29 
75°46 325 

j 15°35 Ue AT 

Mean 76°74 Mean 3°55 


The determinations of sihosplhaite and of sulphuric anhy- 
dride are placed opposite the silver determinations to which 
they belong. The oxygen determinations are distinct. 

The most reasonable interpretation of these results is that . 
we have to do with a double sulphate of silver hemioxide and 
protoxide in which a portion of the sulphuric acid is replaced 
by phosphoric. The proportion of phosphoric acid seems to 
be nearly constant, three concordant analyses having given 
2°09, 2°30, and 2°18, with a mean of 2°19. These proportions 
may be expressed by the formula 


7(AgSO,Ag,8O,H,O) + Ag,PO,Ag.PO,. 


The comparison of this formula with results obtained is as 
follows: 


M. C. Lea—Silver Hemisulphate. 327 


Calculated. Found (Mean). 
He oe a Si AN eet 76°79 76°44 
SOc ease tae 15°67 16°35 
PON ener iOS 219 
ON eS ate ed 3°80 3°29 
BO ses seed ie 1°76 1°78 
100°00 100°08 


This large molecule results from the relatively small propor- 
tion of P,O,, and although the figures obtained for phosphoric 
anhydride are very concordant, it perhaps is better to consider 
the substance as a double sulphate in which part of the sulphuric 
acid is liable to be substituted by phosphoric. If the silver 
phosphate is taken as adventitious, the formula becomes sim- 
ply Ag,SO,, Ag,SO,, H,0. 

Decompositions.—The action of alkaline hydroxides is con- 
firmatory of the above conclusions, and also offers further 
proof of the great stability of the substance. 

When the double salt is placed in contact with excess of 
dilute sodium hydroxide it blackens, being converted into a 
mixture of the hemioxide which is intensely black, and the 
normal oxide. This decomposition, however, takes place 
much more slowly than with the salts of the protoxide, so that 
(unless heat has been applied), if after ten or fifteen minutes 
the alkali is poured off and the oxides are dissolved with 
dilute nitric or sulphuric acid a considerable residue is found 
of the red-brown double salt which has escaped decomposition. 

With continued treatment with sodium hydroxide (that 
obtained from metallic sodium was used as being absolutely 
free from chlorine, the decomposition is complete. 

The oxide thus precipitated was thoroughly dried at 160°— 
170° C., weighed and ignited. Five determinations of oxygen 
from various specimens gave 4°73 ; 4°63, and again 4:24; 4:19; 
4-17 per cent of oxygen respectively. A salt with the consti- 
tution already described should yield one molecule each of 
hemioxide and of normal oxide, and this mixed oxide should 
contain 4°68 per cent of oxygen. We have then: 


Mean of 5 
: determinations. Calculated. 
Oxygen per cent!) 2.2.) 4:39 4°68 


The double salt is more readily decomposed by hydro- 
chloric and hydrobromie acid or even by alkaline chlorides or 
bromides. Under their action it instantly blackens. That 
part of the silver that exists in the form of hemisulphate is 
converted into black hemichloride or bemibromide. The 
extreme instability of these hemihaloids causes them sponta- 


AM. JOUR. ScI.—THIRD SERIES, VoL. XLIV, No. 262.— OcToBEr, 1892. 


328 M. C. Lea—Silver Hemisulphate. 


neously to resolve themselves into metal and normal haloid. 
They rarely remain as hemihaloid for more than an hour or 
two, and often for much less time. The change is often quite 
sudden and is easily observed by the alteration of color, the 
black of the hemihaloid passing into the metallic gray color 
belonging to a mixture of normal haloid with metalli¢ silver. 
The hemibromide seems to be a little less unstable than the 
hemichloride. 

This instability does not render an analysis impossible since 
both the products of the change are insoluble; but renders it 
somewhat more difficult, as the freshly formed silver haloid 
tends to run through a filter. Sometimes indeed it seems as 
if traces of the silver chloride were for a few moments soluble 
in water with a yellow coloration. The appearance of this 
yellow color in the water is apt to be the first indication of 
the splitting up of the hemichloride. 

Two analyses were made, one of material obtained by acting 
on the brown salt with dilute hydrochloric acid; this con- 
tained 81°79 per cent of silver. One by decomposing it with 
sodium chloride; this gave 81:98 per cent. .A substance hay- 
ing the formula already given should, by conversion into 
chloride, give a mixture in which two-thirds of the silver 
should exist as hemichloride, and one-third as normal chloride. 
We have then— 

——-Found.—, 
Ie 2. Mean. Calculated. 
Ag per cent._ 81°79 81:93 81°86 82°35 


a result sufficiently close to afford a confirmation of the con- 
stitution assigned. 

When the brown salt is decomposed with dilute hydro- 
bromic acid or an alkaline bromide, a corresponding result is 
obtained. By treatment with hydrobromic acid a mixed 
bromide resulted which proved to contain 66-06 per cent of 
silver. 

A general consideration of all the reactions which I have 
obtained seems to indicate that the action of sulphuric acid 
and sodium hypophosphite on silver carbonate does not 
lead directly to the production of the double salt which I 
have described, but that the hemisalt is produced in excess, 
often in large excess; that the nitric acid oxidizes this excess, 
being able to attack the free hemisalt, but not that portion 
which is combined with protosalt and so rendered stable. It 
follows that whatever has been the original relative propor- 
tion between the two salts the nitric treatment leaves always 
one molecule of each. If it were possible to control the 
formation it is not improbable that a pure hemisulphate might 


en 


M. C. Lea—Silver Hemisulphate. 329 


be obtained. But the action of the hypophosphite tends so 
strongly to carry the reaction still further that reduced silver 
appears, and in removing this with nitric acid the double salt 
results. A confirmation of this is found in the fact that the 
treatment with nitric acid much reduces the deep terra cotta 
color of the original product. If this difficulty can be over- 
come we may yet obtain hemisalt isolated. 


There is reason to suppose that numerous other compounds 
of silver hemioxide with oxyacids may exist. These com- 
pounds cannot be obtained by acting on the normal salts with 
sodium hypophosphite or with hypophosphorous acid, but it 
appears probable that they may be produced when the normal 
salts are formed in the presence of sodium hypophosphite. 
If to the last named salt we add a solution of a salt capable of 
precipitating silver nitrate, and then further add silver nitrate, 
we obtain precipitates which after standing some hours with 
frequent stirring appear to contain compounds of silver hemi- 
oxide. But these products do not resist the action of nitri¢ 
acid; consequently there appears to be no means of purifying 
them and of deciding with certainty as to their nature. 

When sodium citrate and hypophosphite are dissolved 
together and a little silver nitrate added to get rid of chlo- 
rides, then after standing and filtering more silver nitrate is 
added, a precipitate is obtained which after a time appears to 
contain silver hemicitrate in an impure form. When a little 
of this precipitate is put into much water containing a trace of 
ammonia (five or six drops to 100 e. ¢.), a fine rose-red solution 
results. 

Most oxysalts of silver are darkened by light. Ina paper 
published in this Journal for July, 1887, I mentioned that 
films of these salts exposed to light and then treated with 
dilute hydrochlorie or hydrobromic acid appeared to be con- 
verted into hemichloride or hemibromide, and argued there- 
from that oxyacid hemisalts of silver must exist, and be 
formed by action of light on normal salts. I believe that I 
have been able to prove the existence of a hemisulphate with 
a strong probability that many other hemisalts may be formed 
both by the action of light and also by purely chemical means. 
It is possible that at some future time we may succeed in 
obtaining some of these compounds in a state of purity. 


330 Scientifie Intelligence. 


SCIENTIFIC INTER LULG EN 


I. Grouoey. 


1. Geology of the Taylorville Region of California ; by J.S. 
DiLteER, pp. 369-394 of the Bull. Geol. Soc. America, 1892. 

Jura and Trias at Taylorville, California, by ALpHEus Hyatt, 
pp. 395-412, ibid. 

In these two papers is found the first recognition of the Lias in 
North America. The region of this discovery is in Plumas Co., 
California, near the summit of the Sierra Nevada, and is the 
same that afforded the fossils, in the survey under Professor J. D. 
Whitney, that were studied by Gabb and proved to represent the 
Upper Triassic and the Jurassic formations. The recent collec- 
tions of Professor Hyatt have confirmed the results of Mr. Gabb, 
and, besides adding to the number of Upper Triassic species, 
have afforded over 40 Liassic, a large number of the Middle Jura 
or Oolite, and others that are referred to the Callovian and 
Corallian of the Upper Jura. 

Mr. Diller, from his study of the stratigraphy of the region, 
makes the total thickness of its stratified rocks, exclusive of the 
gravels, to be over 24,500 feet. Of this series, about 17,500 are 
Paleozoic, 4700 Triassic, 450 Liassic, 530 Middle Jura, and 1000 
Upper Jura—5o0 of the last in each of its subdivisions. The 
rocks are shown to be in overthrust flexures and upthrust faults, 
with the thrust in each to the eastward. Mr. Diller finds evi- 
dence that there was a profound upturning at the close of the 
Carboniferous; another feebler disturbance after the Triassic, 
and a great upturning again with flexures of the rocks after the 
Jurassic and probably immediately following this period. His 
paper contains sections illustrating the flexures and faults, with a 
full account of the stratigraphical results reached. 

2. Geological Survey of the State of New York. Palcon- 
tology: Volume VIII, An Introduction to the study of the 
genera of Paleozoic Brachiopoda. Part I. By James Hatt, 
State Geologist and Paleontologist, assisted by Joun M. 
CrarKe. Albany, 1892, 4to, pp. i-xvi, 1-367, with 39 figures in 
the text and 44 lithographic plates——Part I, now published, 
includes all the genera of paleozoic inarticulate brachiopods, 
together with the Orthoids, Strophomenoids, and Productoids of 
the articulate section. The Terebratuloids, Rhynchonelloids, Pen- 
tameroids, and spire-bearing forms are te appear in a subsequent 
volume. Practically this work fulfills the function of a final 
arbiter on questions of generic limitations. Great care has been 
taken to investigate type species and upon them to base the 
generic diagnoses. The manifest plan is to give of each genus, 
(a) accurate illustrations, (0) the bibliography and synonymy, 
(c) a diagnosis of internal and external characters, (d) the type 
species, (e) general observations on the structure and affinities, 


Geology. 331 


and other facts of interest and importance. It would appear, at 
first sight, that a large number of new genera are proposed, and 
that most of the old familiar genera are present under unfamiliar 
guises, but a closer inspection shows that the number of actual 
new names is few. The others are rehabilitated terms, nearly 
forgotten since their origin, and now re-defined and applied to 
distinct groups of forms or types of structure. Thus the subject 
has been simplified by breaking up many of the old heteroge- 
neous groups, such as Discina ‘and Orthis, into clear cut minor 
genera or subgenera, which are now available for accurate sys- 
tematic work. The authors have abstained from the exact use 
of family or other taxonomic designations except the two great 
divisions Inarticulata and Articulata. 

Lingula is the first genus discussed, but it is not necessarily 
considered as the primitive type of inarticulate brachiopods. 
This view is supported by the geological history, anatomy, and 
development. Lingulella and Lingulepis are regarded as fore- 
runners of Lingula, and connecting links to the Obolelloid type. 
Modifications of the nature of septa produced by the deposition 
of shelly matter about the muscular and parietal bands produced 
related genera, such as Dignomia and Glottidia. Special 
features developed about the cardinal areas resulted in forms for 
which the new generic terms Barroisella and Tomasina are pro- 
posed. Other structures arising from mechanical necessity, as 
the elevation of the anterior edges of the muscular attachments 
to compensate for hepatic and ovarian pressure resulted in the 
formation of the vaulted platform of Lingulasma. The authors 
consider this feature of much importance. It first appears in 
Lingulops, and reaches a higher development in Lingulasma. 
Whether this character in these genera is in direct genetic line 
to Trimerella, or whether it is a morphological equivalent, may 
be questions for further discussion. 

Among Discinoid shells the new genus Discinopsis of Matthew 
is first defined, and the subgeneric divisions of Orbiculoidea, 
Hhlertella, Lindstreemella, and Roemerella, are proposed, based 
upon the features of the pedicle opening and form of the ventral 
valve. Of especial interest and importance are the observations 
on the development of the pedicle opening in Orbiculoidea, 
Schizocrania, Trematis, and Discinisca, showing their genetic 
relations in that Discinisca and Orbiculoidea pass through 
young stages comparable with adult conditions of Schizocrania. 

Besides the current terms Platystrophia, Bilobites, Schizo- 
phoria. etc., founded upon groups which have been separated 
from Orthis, the authors have introduced seven new divisions 
making altovether fourteen including Orthis as restricted. The 
new names proposed are: Plectorthis, Dinorthis, Plesiomys, 
Hebertelia, Heterorthis, Dalmanella, and Orthotichia. 'Three 
new names are also applied to forms related to Clitambonites 
(= Orthisina VOrb.); viz. Billingsella, Protorthis, and Poly- 
teechia. 


882 Scientific Intelligence. 


Many important changes have been introduced among the 
Strophomenoids and Productoids. Str ophomen« is restored to its 
original type S. rugosa Rat. = Leptena planumbona Hall. This 
leaves most of the species known as Strophomena, and typified 
by S. alternata, without a name. For this group the genus 
Rufinesquina is proposed. Leptena rests on its original species 
L. rhomboidalis Wilckens, sp. (= LZ. rugosa Dalman), and species 
for many years passing as Leptena sericea, L. transversalis, etc., 
now fall under Plectambonites Pander, Streptorhynchus is re- 
stricted to a species of the type of S. pelargonatum, a Permian 
fossil, and nearly all the species commonly known under this 
designation from the Silurian and Devonian now come under the 
genus Orthothetes of Fischer de Waldheim. In addition to 
Rafinesquina, the following names are proposed for new generic 
and subgeneric types among the Strophomenoids and Productoids: 
Orthidium, Kayserella, Pholidostrophia, Leptostrophia, Amphi- 
strophia, Leptella, Christiania, Anoplia, Chonostrophia, and 
Chonopectus. 

It will probably be found that Zropidoleptus and Vitulina 
belong with the genera included in this volume. Oldhaminua, 
Lyttonia, and Lichtofenia, also pertain to this portion. It is 
hoped that a recognition of ordinal, subordinal, and patronymic 
subdivisions will be accorded in the final work as an expression 
of the views of the authors. Several anomalous inferences upon 
related genera which have a structurally intermediate genus ap- 
pearing at a later geological period could perhaps be better ex- 
plained as morphological equivalents. In other cases geratology 
is evidently an important factor. 

Any just criticism of this work would deal chiefly with a few 
details of observations, minor differences of opinion, and trivial 
points of generic relationships, and would in no way impair its 
general usefulness. It must therefore stand as of the highest 
authority on the genera of Paleozoic Brachiopoda. (Wane 13) 

Report of the Arkansas Geological Survey for 1890, 
Tes C. Branner, State Geologist. Vol. Ill, Whetstones and 
Novaculites of Arkansas, by L. 8. GriswoLtp. 444 pp. 8vo, 
with colored geological maps and other illustrations.—Mr. Gris- 
wold’s report has great value, alike historical, practical and 
scientific. The origin of the novaculite stratum, which in its 
pure form is 994 per cent silica, is referred to simple sedimenta- 
tion, like that of an ordinary sandstone; it is a very fine siliceous 
sand-deposit, somewhat calcareous, from which the minute cal- 
careous grains have been leached out, so as to render the rock 
porous. “Only small portions of the stratum have the fineness of 
texture fitted for the best whetstones. The stratum is of the age 
of the lower part of the Trenton, as proved by the author thr ough 
the discovery of Graptolites, and has a thickness of about 1200 
feet. It is underlaid by 1300 feet of shales, limestones and sand- 
stones of older Paleozoic, and overlaid directly by 1200 to 1500 
feet of Subcarboniferous beds, the Upper Silurian and Devonian 


Geology. 333 


being absent. These rocks are upturned and in flexures, making 
ridges of what is called the Ouachita mountain system, extend- © 
ing from Little Rock, Central Arkansas, westward into the In- 
dian Territory. The axis of uplift, about east and west in direc- 
tion, ‘‘strikes toward the disturbed Paleozoic region between 
Mississippi and Tennessee, which region has been regarded as a 
southwestern termination of the Appalachian system.” 

4, On the occurrence of Artesian and other underground 
waters in Tecas, Eastern New Mexico and Indian Territory, 
west of the 97th Meridian ; by Ropert T. Hitt. 166 pp. 8vo, 
with numerons maps, plates, and sections. From the Final Reports 
of the Artesian and Underflow Investigations of the Department 
of Agriculture.—Professor Hill commences his very thorough 
Report with a general review of the topographical features of 
Texas. He mentions in detail the results of Artesian borings 
over the State, and discusses the observed facts in their relation 
to the several rock strata that underlie the surface, and the topog- 
raphy of the different regions. The special conditions on which 
in each region success or tailure depend are pointed out, and in the 
explanations many geological details with regard to the stratifi- 
cation are given and made clear by numerous illustrating sections 
and maps. 

5. Geological Society of America.—A meeting of the Geo- 
logical Society, of which Professor G. K. Giibert, is President, - 
was held at Rochester, New York, on the 15th and 16th of 
August, immediately preceding that of the American Association. 
The following papers were read: L. C. Johnson, on Phosphate 
fields in Florida; C. H. Hitchcock, On the Connecticut Valley 
glacier; E. W. Claypole, Dentition of Titanichthys and its allies ; 
G. C. Broadhead, On the Ozarks and the geological history of 
the Missouri Paleozoic; G. F. Becker, On the finite, homogeneous 
strain, flow and rupture of rocks; W. H. Hobbs, Phases in the 
metamorphism of schists in Southern Berkshire; ©. L. Little, 
On a metamorphic conglomerate in the Green Mts.; J. Hall, On 
the Oneonta sandstone; W. Upham, On Drunilins ; G. F. Wright, 
On Extra-morainie drift of the Susquehanna Valley; D. White, 
A new Teeniopterid and its allies; A. 8. Tiffany, Overturn of L. 
Silurian strata in Rennselaer Co., N. Y.; President Gilbert, On 
Coon Butte of Arizona and the theories of its origin. 

The Society will hold its next meeting at Ottawa, Canada, 
commencing on the 28th of December. 

6. Albirupean Studies ; by P. R. Unter. Trans. Md. Acad. 
Sei., 1892, pp. 185-201.—We have here another strong effort of 
this author to vindicate his Albirupean formation, as outlined in 
1888. He now expands it to include the entire clay series of 
New Jersey and the Laminated Sands of that state, also all of 
the Potomac formation of McGee coastward of the Iron Ore 
Clays of Maryland, and prolongs it southward into Virginia to 
take in the freestone quarries of Aquia Creek and Fredericks- 
burg. This leaves very little of the great Atlantic Clay Belt for 


334 .« Scientific Intelligence. 


any one to contend about, because it is now known that the 
Amboy Clay flora occurs near the base of the Tuscaloosa forma- 
tion in Alabama and Mississippi. He has therefore proved too 
much and is anticipated by Dr. Eugene Smith, at least as to his 
proposed name. And really this is here the main thing, since 
the facts have been long known and accurately mapped, at least 
in New Jersey. The great question is that of correlating the 
Potomac formation with the New Jersey beds, or of showing 
what relation subsists between them. On this question the pres- 
ent paper throws no clear light. The one service which Prof. 
Uhler’s investigations are doing is that of drawing attention to 
the fact that the great Lower Cretaceous non-shell-bearing belt 
of the Atlantic border region, though doubtless a geological unit 
(which he denies), occupied a vast period in its deposition, was 
attended by great vicissitudes and oscillations of level, and must 
be studied as a series of successive deposits rising stratigraph- 
ically from its landward toward its coastward margin and 
changing greatly from one level to another. L. F. W. 

7. The Fossil Flora of the Bozeman Coal Field; by ¥. H. 
Know tron. Proc. Biol. Soc. Washington, vol. vii, July 1892, 
pp. 153-154.—In this short paper Prof. Knowlton sums up the 
results of a prolonged investigation soon to be published in full 
by the Geological Survey. Altogether 43 species of fossil plants 
have been found in the Bozeman coal field only three of which © 
are new, most of the others occurring in other parts of the west. 
‘The small number of Fort Union species seems to show that 
these deposits do not form a part of the series of beds that 
extend along the Missouri and Yellowstone rivers in Dakota and 
Montana. On the other hand the forms found are largely those 
of the true Laramie and overlying Denver formations of Colorado 
and Wyoming, between which they are pretty equally divided. 
This seems to fix the horizon of this coal region with consider- 
able accuracy, and shows that the great Laramie sea occupied 
the same position relatively to the Rocky Mountain uplift in 
Montana as it does farther south. The most interesting form is 
the Thinnfeldia polymorpha, which seems to be a sort of con- 
necting link between the ferns and the conifers of the Ginkgo 
type, and is also strongly suggestive of the Glossopterid forms of 
Australia and India. EES We 

8. Paléontologie Végétale (Ouvrages publiés en 1890), par R. 
ZeILLER. Extrait de Annuaire Géologique Universel, Tome 
VII, 1890, pp. 1115-1157, Paris, 1892. This is another of the 
series of admirable reviews of paleobotanical literature by M. 
Zeiller, of which four others have previously appeared. It is 
very thorough and searching, no less than 138 different works 
and papers being treated. The plan is to deal first with the gen- 
eral works and discussions and then to take up the special works 
in the ascending geological order of the formations. These are 
subdivided into Paleozoic, Antecretaceous Secondary, and Cre- 
taceous and Posteretaceous. A special department is devoted to 


Geology. 335 


fossil woods. The method is expository rather than critical and 
the space is well adjusted to the importance of the subjects re- 
viewed. The literature is referred to by numbers and the titles 
are collected together in an alphabetical list, but unfortunately 
in a separate part of the volume (pp. 98-103)—a serious defect 
in the book-making, but for which our author is not responsible. 
The most important works that appeared during the year 1890 
were Professor Fontaine’s Flora of the Potomac Formation, 
Renault and Zeiller’s Coal Flora of Commentry, Saporta’s 
Jurassic Flora (completed in this year), the Paleophytology of 
Zitte’s Handbuch, brought to a conclusion by Schenk, and 
Zeiller’s Fossil Flora of the Carboniferous and Permian basin of 
Autun and Epinac. Among the leading discoveries of the year 
may be noted: that by Renault of the large petioles called Myel- 
oxylon in direct relation with the ferns Alethopteris and Neu- 
ropteris; that by Williamson of secondary wood in certain ferns ; 
that by Renault of a true Equisetum in the Carboniferous; that 
by Marion in the Permian of Lodéve of peculiar strobiles (Gom- 
phostrobus) which seem to form a connecting link between 
Walchia and Ginkgo; that by Saporta of dicotyledonous plants 
in the Lower Cretaceous of Portugal; and that by Dawson and 
Penhallow of a Rhizocarp (Azollephyllum primcevum) allied to 
Azolla, in the Tertiary of British Columbia. L. F. W. 

9. Sylloge Fungorum Fossilium hucusque cognitorum. Auc- 
tore A. Mrscuinetul. Patavii, 1892.—This is an octavo pam- 
phlet of 73 pages and will form part of the tenth volume o 
Saccardo’s great Sylloge Fungorum so well known to botanists. 
It was well, and in line with modern methods, that Saccardo 
should include the fossil forms in his description of all the fungi 
known to botany, and this part could not have been intrusted to 
any one more competent than Professor Meschinelli. According 
to this enumeration there are now known to science 329 species 
of fossil fungi, which are assigned to 41 genera. Most of these 
latter are named from their resemblance to living genera by add- 
ing to the generic name the termination -ites. The largest genus 
is “Sphierites with 100 species, which is followed by Xylomites 
with 56, Rhytismites with 23, Phacidites with 18, Depazites and 
Hysterites with 16 each, Phyllerites with 15, and Sclerotites with 
13. Most of these occur as spots on dicotyledonous leaves, 
chiefly in the Tertiary. The genera Archagaricon, Peronospor- 
ites, Protomycites, Excipulites, “and some of the species of other 
genera, are from the Carboniferous, and there are a few Mesozoic 
forms. The Polyporites Bowmani of Lindley and Hutton from 
the coal measures of Denbigshire, long regarded as the scale of a 
fish, is included, as is the Gyromyces Ammonis of Gippert, which 
"most other authors treat as a shell, and which has been otherwise 
named Spirorbis carbonarii; but in such doubtful cases atten- 
tion is called to the conflicting views. The plan of the work 
embraces pretty full references to the literature of each species, 
a very brief character, and a statement of the habitat, which 


336 Scientific Intelligence. 


features render the work exceedingly useful independently of 
any questions as to the real nature of doubtful forms, 1. F. w. 
10. L Tronchi di Bennettitee det Musei Italiani. Notizie 
storiche, geologiche, botaniche ; dei Professori Senatore G. Cap- 
ELLINI e Conte E. Sorms-Lavpacu, Con cinque tavole. Bologna, 
1892. Estratta dalla Serie V, Tomo II delle Mem. Real Accad. 
Sci. Ist. di Bologna. —Capellini writes the historical and geologi- 
eal, and Solms-Laubach the botanical part of this memoir, giving 
a very full account of the discovery and the real nature “of all 
the cycadean remains that have been long accumulating in the 
various Italian museums, one specimen dating back as far as 
1745. Besides the eight species of Cycadeoidea which are 
described and figured one other form is treated as belonging to a 
different genus and named Cycadea Imolensis. Count Solms 
reserves the name Bennettites for the sole B. Gibsonianus, the 
nature of whose fructification is known and has been fully treated 
by him in a previous memoir (see this Journal, vol. xli, p. 531). 
Mention is made of three American forms. The specimen found 
at Golden, Colorado, to which Lesquereux gave the name Zamio- 
strobus mirabilis was sent to Solms-Laubach by the U. 8S. Na- 
tional Museum, with permission to dissect and describe it. It 
has been returned together with two slides showing its internal 
structure, but the only description is contained in letters from 
him. In these and in the present work he has renamed it Cyca- 
deoidea Zamiostrobus, which name his label with the specimen 
also bears, but no ficures are given. The Zysonia Marylandica 
of Fontaine from the iron ore clays (Potomac formation) of 
Maryland is also regarded as a Bennettites or a Cycadeoidea, and 
Capellini says that it closely resembles C. Maraniana. The C. 
munita of Cragin from the Cheyenne Sandstone is supposed to 
be a related form. Lb. F.-W. 
11. Ueber den gegenwdrtigen Standpunkt unserer Kenntniss 
von dem Vorkommen fossiler Glacialpflanzen. Von A. G. 
Narsorst. Bihang till svenska Vet..Akad. Handlingar. Band 
17. Afd. III, No. 5. Stockholm, 1892.—It is matter for congrat- 
ulation that this valuable paper should have been published in 
German instead of Swedish. It contains a résumé of the pro- 
longed and extensive researches of the author into the occurrence , 
of tossil plants in glacial deposits. These began nearly 25 years 
ago and his contributions to the subject embrace more than a 
score of titles. The present summary, however, goes further and 
includes the results of the labors of others, and, though brief, 
presents a bird’s-eye view of the whole field. It is accompanied 
by a map of northern Europe with the areas and particular 
localities where these plants are found clearly marked. The 
principal countries in which these occur are: Sweden (chiefly in 
Scania at the extreme south, but also in Ostgothland, Gotland, 
and Jemtland), Norway (at Leine in Gudbrandsdalen), Denmark 
(Seeland, Méen, Bornholm, Jutland), Russia (Esthland, Livland), 
North Germany (East and West Prussia, Pomerania, Mecklen- 


Miscellaneous Intelligence. 337 


burg, Schleswig-Holstein), Great Britain (Devonshire, Norfolk, 
Suffolk, Yorkshire and near Edinburgh), Switzerland (Cantons of 
Zurich, Thurgau Luzern, Neuchatel), Wiirtemberg (Upper Swa- 
bia), Bavaria (Kolbermoor), Hungary (Felek in the South Car- 
pathian mountains), France (near Nancy). In nearly all cases 
the forms thus discovered have been identified with those now 
inhabiting the colder parts of the northern hemisphere. Their 
great southern range is conclusive as to the change that has taken 
place in the climate of Europe. L.. F. W. 


II. MiscELLANEOUS SCIENTIFIC INTELLIGENCE. 


1. American Association for the Advancement of Science.— 
The 41st meeting of this association was opened at Rochester, 
N. Y., on the 17th of August, under the Presidency of Professor 
Joseph LeConte. The addresses of the Vice-Presidents of the 
sections were as follows: Professor J. R. Eastman, of the Astro- 
nomical Section, On the neglected field of Fundamental Astron- 
omy; Professor B. F. Thomas, of the Physical Section, On 
Technical education in High Schools and Universities; A. 
Springer, of the Chemical Section, On the Micro-organisms of 
the soil; H. 8. Williams, of the Geological Section, On the 
Scope of Paleontology and its value to Geologists; Professor S. 
H. Gage, of the Biological Section, On the Comparative Physiol- 
ogy of respiration; W. H. Holmes, of the Section of Anthro- 
pology, On the evolution of the Esthetic; Professor J. B. 
Johnson, of the Section of Mechanical Science and Engineering, 
On the Applied Scientist; Lester F.. Ward, of the Economical 
Science Section, On the Psychological basis of social economics. 

The Address of the retiring President, Prof. A. B. Prescott, 
considered “the work that is wanted in the science of Chemistry.” 

Excursions were taken on Saturday in four directions, to Port- 
age, Stony Brook Glen, Niagara Falls and Canandaigua Lake. 
The salt mines also, 20 to 30 miles south of Rochester, were visited. 

The President and Vice-Presidents chosen for the following 
year were as follows: Presipent, Wm. Harkness. VicxE-PRrest- 
DENTS, C. L. Doolittle, in the Mathematical and Astronomical 
section; E. L. Nichols, in the Physical; E. Hart, in the Chemi- 
cal; 8S. W. Robinson, in that of Mechanical Science and Engi- 
neering; C. D. Walcott, in the Geological; H. F. Osborn, in the 
Zoological; C. E. Bessey, in the Botanical; J. O. Dorsey, in the 
Anthropological; W. H. Branner, in the Section of Economic 
Science and Statistics. Madison, Wisconsin, was selected for the 
next place of meeting. 


List of papers accepted for reading. 


Section A. Mathematics and Astronomy. 


J. A. BRASHEAR: Huropean observations. 
S. C. CHANDLER: On the conflict of observation with theory as to the earth’s 
rotation. 


338 Miscellaneous Intelligence. 


TD. P. Topp: Meteorological observations made in April, 1890, 1891, 1892, in 
the totality-path of the eclipse of 1893. April 16. 

L. A. Bauer: The secular motion of a free magnetic needle. 

M. MerRIMAN: On the discriminators of the discriminant of an algebraic 
equation. 

G. HK. Hate: The spectroheliograph of the Kenwood Astro-Physieal Observa- 
tory. Chicago, and results obtained in the study of the sun. Forms of solar 
faculee. 

C. L. DoouittLe: Latitude of the Sayre Observatory. List of 30 new proper 
motion stars. 

ALEXANDER MACFARLANE: On the imaginary of algebra. 

R. S. Woopwarp: The iced-bar base apparatus of the U.S. Coast and Geo- 
detic Survey. On the general problem of least squares. 

A. W. PuHILLips: Models and machines for showing curves of the third 
degree. 

T. H. Sarrorp: Least square fallacies. Differential formule for orbit cor- 
rections. Proper motion of 89 stars within 10° of the north pole, with remarks 
on the present state of the problem of the solar motion. 

EK. Hastincs Moore: Concerning a congruence-group of order 360 contained 
in the group of linear fractional substitutions. 

W. Hoover: On the intersection of an equilateral hyperbola and the sides of 
a plane triangle—a-question in trilinears. 

W. A. RoGERS: On the construction of a prime vertical transit instrument 
for the determination of the latitude of Harvard College Observatory. 

A. S. HarHaway: Lineo-lmear vector functions. 

EK. B. Frost: Thermal absorption in the solar atmosphere. 

J. E. KeRSHNER: Electric lights for astronomical instruments. 

.J. D, WARNER: Practical rules for testing whether a number is divisible by 7, 
or any other small prime; and if not divisible, to ascertain the remainder. In- 
crease in constant for addition in testing for integral values in the equation of 
quarter squares. 


Section B. Physics. 


EK. S. Ferry: Persistence of vision. 

G. W. HoLuEy: Experiments on the ocular spectrum of the eye and the 
image presented to the brain. 

C. A. OLIveR: Description of a contrivance intended for the study of percep- 
tion at definite distances. 

E. Merritt: Note on the photography of the manometric flame and the 
analysis of vowel sounds. 

G. W. Hove: On the sensitiveness of photographic plates. 

W. 5S. Frankcin: EK. M. F. between normal and strained metals in voltaic 
cells. 
M. Merriman: Influence of the moon on the rainfall. 

D. P. Topp: On the mechanical and physical means of aérial transit without a 
propeller. 

E. B. Rosa: Further experiments on the specific inductive capacity of elec- 
trolytes. 

OC. B. Tawine: A photographic method of mapping the magnetic field. 

F. P. WuHirman: Constancy of volume of iron in strong magnetic fields. Note 
on magnetic disturbances caused by electric railways. 

i. L. Nicuous: The distribution of energy in the spectrum of the glow-lamp. 
Absorption spectra of certain substances in the infra-red. 

J. E. Ottver: Note on the Lesage-Thomson theory of gravitation. 

A. HE. Dotpgear: A mechanical model of electromagnetic relations. 

W. L Stevens: An experimental comparison of formulee for total radiation 
between 15° C. and 110° C. 

H. RuBENS and B. W. Snow: On the dispersion of radiations of great wave- 
lengths in rock salt, silvite and fluorspar. 

B. W. Svow: On the distribution of energy in the are. On the infra-red 
spectra of the alkalies. 

G. Hryricus:. On the mechanics of the three states of aggregation. 


Miscellaneous Intelligence. 339 


Section C. Chemistry. 


G. ARCHBOLD: The albuminoids of maize. 

W. P. Mason: Post-mortem imbibition of arsenic. Effect of sedimentation 
upon self-purification of running streams. The value of a water analysis. 

S. A. Lattimore: Presentation of samples from the salt mines of New York. 

G. Hinricus: On the mechanical determination of the stereographie constitu- 
tion of organic compounds. 

W. R. ORNpDoRFF: On the decomposition of acetone with concentrated sul- 
furie acid. 

Lavra O. Tarsorr: Itacolumite from North Carolina. 

H. Carrineton Bouton: A select bibliography of chemistry. 
- A, TUCKERMAN: Notes on a bibliography of mineral waters. 

E. Harr: Copper sulfate as a material for standardizing solutions. 

W. A. Noyes: An effective condenser for volatile liquids and for water 
analysis. Di-ethyl-carbinamin and its conduct toward nitrous acid. 

A. B. Prescott: The iodomercurates of organic bases. 

M. GomBere: Tri-methyl-xanthin and its derivatives. 

H. W. WILEY: Some points in connection with the composition of honey. A 
method of polarimetric observation at low temperatures. 

C. P. TOWNSEND: Note on the effect of fertilizers upon the juice of the sugar- 
cane. 

EK. A. DE SCHWEINITZ: The enzyms or soluble ferments of the hog-cholera 
germ. 

E. GOLDSMITH: Catalytic influence of ammonia on amorphous substances to. 
induce crystallization. ; 


Section D. Mechanical Science and Engineering. 


J. B. JOHNSON: Extensometer for measuring distortion of specimens under 
test (instrument exhibited). Peculiar visible strain in steel when tested in tension, 
compression and cross-breaking. 

Frep. T. Gatse: Relative economy of the single cylinder air-compressor 
with cooling by a spray of water and the present economy of the compound 
compressors at Qua de la Gare, Paris. 

A. M. RosesprouGH: A new window ventilating appliance. 

Wm. A. RoGers: Investigation of a 21 1-1 feet precision screw. Exhibition 
and description of combined yard and meter standard bar. 

R. S. Woopwarp: On the use of long steel-tapes in measuring base-line. 
Report of U.S. C. and G. Survey. 

K. W. Bemis: Results of municipal ownership of gas-works in the U. 8. dur- 
ing 1891. 

G. W. Hovucu: Description of a transmission dynamometer. 

J. B. Wess: Bending tests of timber. 

J. E. Denton: Method of measuring loss of power and drop of pressure be- 
tween cylinders in multiple-cylinder engine. 

' D. S. Jacospus: Measurements of total heats of combustion. Use of anemom- 
eters for measuring velocity of air in mines. 

J. E. Denton and D. S. Jacosus: Steam economy of the engines of the 
screw ferry boat ‘‘ Bremen.” 

DEVoLson Woop: Negative specific heats. 


Section E. Geology and Geography. 


A. Houuick: Paleobotany of the yellow gravel at Bridgeton, N. J. 

G. F. Kunz: The mining, metallurgical, geological and mineralogical exhibits 
to be shown at the World’s Columbian Exposition 

J. CRAWFORD: Cerro-Viejo and its cones of volcanic ejecta and extrusion in 
Nicaragua. 

W. J. McGee: Pleistocene geography. Distributions of the LaFayette forma- 
tion. 

W. Upnam: Submarine valleys on continental slopes. 

EK. D. Cope: Cenozoic beds of the staked plains of Texas. 


340 Miscellaneous Intelligence. 


A. L. Arey: Exhibitions of Guelph fossils found in Rochester, N. Y. 

JOHN Kost: The American mastodon in Florida. 

N. H. WINcHELL: Some problems of the Mesabi iron ore. 

V. CoLtyin: The mathematics of mountain sculpture. 

R. T. Hitt: The volcanic craters of the United States. Recent geological 
explorations in Mexico. The homotoxic relations of the North American Lower 
Cretaceous. 

S. A. LATTIMORE: Presentation of samples from the sait mines of New York. 

C. H. Hitcucock: Terminal moraines in New England. 

EK. W. CLAYPOLE: A passage in the history of the Cuyahoga River. 

F. LEVERETT: Notes bearing upon the changes of the Pre-glacial drainage of 
western Illinois and eastern Lowa. 

A. A. Wricst: Extra-morainic drift in New Jersey. 


Section F. Biology. 


J. C. ARTHUR: How the application of hot water to seed increases the yield. 

L. H. Battery: On the supposed correlation of quality in fruits—a study in 
evolution. 

W. J. Beau: Spikes of wheat bearing abnormal spikelets. A study of the 
relative lengths of the sheaths and internodes of grasses for the purpose of 
determining to what extent this is a reliable specific character. 

N. L. Britton: Notes on Ranunculus repens and its eastern North American 
allies. Notes on a monograph of the North American species of Lespedeza. 

F. V. CovitLe: Geographic relationship of the flora of the high Sierra Nevada, 
California. Sketch of the Flora of Death Valley, California. Characteristics 
and adaptations of desert vegetation. 

' J. H. Comstock: The descent of the Lepidoptera; an application of the 
theory of natural selection to toxonomy. 

O. F. Cook: Do Termites cultivate fungi? 

EK. D. Cope: A new form of Marsupialia from the Laramie. 

W. M. BeaucHAMP: Variation in native ferns. Notes on some fresh water 
Mollusks. m 

W. A. KELLERMAN: Notes on yellow pitch-pine, Pinus rigida Mill, var. lutea. 
Germination at intervals cf seed treated with Fungicides. 

M. B. Waite: The fertilization of pear flowers. 

C. W. Srttes: On the adult cestodes of cattle and sheep. 

H. L. RusseLu: Non-parasitic bacteria in vegetable tissue. Bacteriological 
investigations of marine waters and the sea floor. 

H. E. Weep: The insect fauna of the Mississippi bottoms. 

W. W. RowLee: The root system of Mikania scandens L. Adaptation of 
seeds to facilitate germination. 

C. W. Stines: Report of Biological Section of the committee on the Naples 
table. 

D. G. Fatrcuinp: Live-for-ever eradicated by a fungous disease. 

G. Vasey: Otto Kunze’s changes in nomenclature of North American grasses. 

B. E. Fernow and G. B. SupwortH: Revised Horne Benne of the arbores- 
cent flora of the United States. 

A. H. TurrLe: The proposed Columbus biological stations in Jamaica. An 
interesting case of parasitism. ; 

J. H. Stonter: The conditions which determine the distribution of bacteria in 
the water of rivers. 

C. W. Hareitt: Biological notes on fauna of Cold Spring Harbor. Notes on 
Daucus carota. 

W. P. Witson: Adaptation of plants to external environment. 

S. A. BracH: Notes on self-pollination of the grape. 

G. B. SupwortH: Comparative influence of odor and color in attracting 
insects. 

F. B. MAXWELL: Comparative study of the roots of Ranunculacee. 

F. Rota: Shrinkage of wood as observed under the microscope. 

L. H. PAMMEL: Peziza sclerotium. Temperature and some of its relations to 
plant life. 


Miscellaneous Intelligence. 341 


B. D. Haustep: Pleospora cf Tropzeolum majus. Secondary spores of An- 
thracnoses. A Bacterium of Phaseolus. 

T. MEEHAN: The significance of cleistogamy. 

E. W. Doran: The animal parasites of dogs. 

P. A. Fis: A preliminary note on the anatomy of the Urodela brain as 
exemplified by Desmognothus fusca. 

J. B. SmirH: The ‘ maxillary tentacles” of Pronuba. 

L. M. UNDERWOOD: Preliminary comparison of the Hepatic Flora of boreal 
and sub-boreal regions. 

E F. Sire: On the value of wood ashes in the treatment of peach yellows. 
On the value of superphosphates and muriate of potash in the treatment of 
peach yellows. 

. Mac.Losk1: Notes on maize. 
. S. Hopxixs: Contribution on the digestive tract of some N. A ganoids. 

M. Mires: Heredity of acquired characters. 

E. A. DE Scawernitz: The production of immunity in guinea pigs from hog 
cholera by the use of blood serum from immunized animals. 

S. P. Gage: A prelimimary account of the brain of Diemyctylus viridescens 
based upon sections made through the entire head. 

C. V. Rinpy: On Carphoxera ptelearia, the new herbarium pest. The fertili- 
zation of the fig and caprification. 

R. O. Moopy: Note on the appearance of two embryo chicks in a single 
blastoderm. 


2 2 


Section H. Anthropology. 


D. G. Brinton: Anvil-shaped stones from Pennsylvania. Proposed classifica- 
tion and international nomenciature of the anthropological sciences. 

A. W. BurLeR: Some Indian camping sites near Brookville. Prehistoric 
objects from the White Water valley. On some remains from the oldest river 
gravels along the White Water river. NHarthworks near Anderson, Ind. 

L, L. Conant: Primitive number system. 

Laura O. Tarsottr: A few psychological inquiries. 

J. Jastrow: Involuntary movements. 

MatitpA C. Stevenson: Tusayan legends of the Snake and Flute people. 

E. W. Cuaypou“e: A skull of a pig having a flint arrowhead imbedded in the 
bone. 

W. J. McGreEe: Comparative chronology. 

H. T. Cresson: Brief remarks upon the alphabet of Landa. 

F. W. Purnam: The Peabody Museum .Honduras expedition. The Depart- 
ment of Ethnology of the World’s Columbian Exposition. Exhibition of a large 
model of the Serpent Mound of Adams County, Ohio. 

W. M. BeaucuaMp: Early religion of the Iroquois. Early Indian forts in 
New York. 

C. A. HIRSCHFELDER: Evidences of prehistoric trade in Ontario. Ancient 
earthworks in Ontario. 

O. T. Mason: A definition of anthropology. 

F. H. Cussine: Pueblo myth and ceremonial dances. 

C. P. Hart: Demonstration of a recently discovered cerebral porta. 

Dovueias: Ruins of Tiahuanaco. 

8. S. ScovILLeE: Points concerning Fort Ancient. 

T. B. Reppine: Pre-historic earthworks of Henry county, Indiana. 

W. H. Hotmes: On the so-called paleolithic implements of the Upper Missis- 
sippi. ‘The sacred pipestone quarry of Minresota, and the ancient copper mines 
of Lake Superior. Aboriginal quarries of flakable stone, and their bearing upon 
the question of paleolithic man. 

M. H. Savitte: Explorations on the main structure of Copan, Honduras. 
Vandalism among the antiquities of Yucatan and Central America. 

H. C. Mercer: River pebbles chipped by modern Indians, as an aid to the 
study of the Trenton gravel implements. 

W. K. MooreHeaD: Canon and mesa ruins in Utah. Singular copper imple- 
ments and ornaments from the Hopewell group, Ross Co., Ohio. 


342 Miscellaneous Intelligence. 


2. British Association.—The sixty-second meeting of the 
British Association was held at Edinburgh during the week com- 
mencing August 3. Sir Archibald Geikie was the President of 
the meeting. In his address he speaks of the large contributions 
of Edinburgh geologists to geological science and dwells at 
length upon the prominent influence of the views of Hutton. 
Other Presidential addresses were by Professor Lapworth, of the 
Geological Section, on some general facts in the earth’s develop- 
ment; Professor James Geikie, President of the Geographical 
Section, on the origin of coast lines; Professor Schuster, of the 
Physical Section, on the progress in Physical Science during the 
past year; Professor Wm. Rutherford, of the section on Biology, 
on the current theories regarding our sense of color, These and 
other Presidential addresses and reports of papers will be found 
in the numbers of Nature for the month of August and beyond. 


3. On the periodic variations in Glaciers. The following is | 


from a recent communication by Prof. Forel, published in Nature 
of August 18.—The preparatory study which we have made 
within the last few years has shown us that the periodicity of 
glacial variations is much longer than was formerly believed to 
be the case; the popular dictum that the increase in the size of 
glaciers recurs every seven years is certainly incorrect. We can- 
not yet give definite figures, but probably the cycle of glacial 
variation is as much as 35 to 50 years. ‘he latter period alone 
has been studied attentively ; if 1850 or 1855 be fixed upon as 
the epoch of maximum of glaciers, they have been steadily 
decreasing in past years, so that from 1870 to 1875 we were not 
aware of a single one on the increase. In 1875 the Glacier des 
Bossons du Mont Blane gave the signal for a new period by 
commencing to lengthen out ; it was followed in 1878 and 1879 
by the glaciers of Trient and Zigiorenove; then successively by 
some thirty glaciers in different valleys of Le Valais; but the phase 
of increase is not yet general in Le Valais; a number of large 
glaciers, Arolla, Otemma, Corbassiére, Le Gorner, Le Rhone, are 
still decreasing or stationary. It is only of the Mont Blane 
group that the increase can be said to be general; in Le Valais 
it is in process of development, and we are still very far from the 
maximum stage of glaciers. If, as is probable, the maximum 
only arrives at the commencement of next century, the actual 
period of glaciers will have lasted more than fifty years. 

4. Florida, South Carolina and Canadian Phosphates ; by 
C. C. Hayes Mrinar. 224 pp. 8vo. 1892. New York (The 
Scientific Publishing Co.).—As the preface states, this book is 
addressed to those who are commercially interested in phosphates, 
and treats of their mode of occurrence, methods and cost of pro- 
duction, and commercial importance. It contains maps of the 
phosphate regions of Florida and South Carolina, and will be 
found a valuable work by those for whom it has been prepared. 


ACP PR EEN, DXe. 


Art. XLIUL.— Restorations of Ciaosaurus and Ceratosaurus ; 
by O. C. Marsa. (With Plates VI and VIL.) 


A NUMBER of restorations of Dinosaurian reptiles have been 
recently made by the writer for the United States Geological 
Survey, and reduced figures of several of these have 
already appeared in this Journal; namely, Brontosaurus and 
Stegosaurus from the Jurassic, and Triceratops from the 
Cretaceous.* T'wo others of interest are given in the present 
article; Claosaurus from the Cretaceous, and Ceratosaurus 
from the Jurassic, as shown on Plates VI and VII. The 
former is a gigantic herbivorous reptile, a typical member of 
the Ornithopoda, and the latter a large carnivorous form of 
the Lheropoda, as these orders have been defined by the 
writer.t Each of these two reptiles is a characteristic example 
of the great order in which it belongs, but both are highly 
specialized, and present. many features not seen in earlier and 
more primitive types. Their representatives in the old world 
are Lguanodon and Megalosaurus, although each of the four 
genera may represent a distinct family. 

It is especially fortunate that each of the restorations here 
presented is based upon the remains of a single individual in 
which both the skull and skeleton were found in position, and 
in remarkable preservation. Additional remains, apparently 
identical with each, have also been secured, and these have 
cleared up several ‘points which otherwise might have been 
left in doubt. These various remains have already been 
described by the writer, and the most important parts figured. 


* This Journal, vol. xli, p. 339, April, 1891; and vol. xlii, p. 179, August, 1891. 
+ Ibid., vol. xxi, p. 423, May, 1881; and vol. xxiii, p. 84, January, 1882. 


Am. Jour. Sci.—Tuirp Series, Vou. XLIV, No. 262.—OcrosEr, 1892, 
23 


344 Marsh— Restorations of Claosaurus and Ceratosaurus. 


Claosaurus, Marsh, 1890.* 


The most important feature in the restoration of Claosaurus 
annectens given on Plate VI is the skull, which will be fully 
described elsewhere, but its main features may be noticed here. 
This skull is long and narrow, with the facial portion especially 
produced. The anterior part is only moderately expanded 
transversely, thus differmg from that of Hadrosaurus 
(Diclonius), a nearly allied form. Seen from the side, the 
skull of Olaosaurus shows a blunt, ragose muzzle, formed 
above by the premaxillary and below by the predentary, both 
probably covered in life with a thick, corneous integument. 

Behind the upper part of this muzzle is an enormous lateral 
cavity, which includes the narial orifice, but was evidently oecu- 
pied in life mainly by a nasal gland, somewhat like that in the 

existing Monitor, and also seen in some Birds. This cavity is 

bounded externally by the nasal bone and the premaxillary. 
The orbit is very large, and subtriangular in outline. It is 
formed above by the prefrontal, frontal, and postfrontal, and 
below mainly by the jugal. There are no supra-orbital bones. 
A distinct lachrymal forms a portion of the anterior border. 
The infra-temporal fossa is large, and bounded below by the 
jugal. There is a thin quadrato- -jugal between the jugal and 
quadrate. The occipital condyle is directed backward and 
downward. 

The nasals are very long and slender, and in front are 
separated by the narrow superior processes of the premax- 
illaries. The frontals are short and broad, and somewhat 
concave above. The parietals are firmly codssified, and very 
small, forming a thin partition between the supra-temporal 
fossee. The latter are bounded posteriorly by the massive 
squamosals, which contain a deep cavity for the head of the 
quadrate, and also overlap the exoccipitals, 

The striking features of the lower jaw are the massive, 
rugose predentary, the large and powerful dentary bone with 
its robust coronoid process, and the very small angular and 
articular bones. 

The teeth are confined entirely to the maxillary and dentary 
bones. They closely resemble those of LHadrosaurus, are 
arranged in the same manner, and appear to be equally 
numerous.t They were well adapted to a diet of soft succulent 
vegetation. 

* This Journal, vol. xxxix, p. 423, May, 1890; vol. xliii, p. 453, May, 1892; 
and vol. xliv, p. 171, August, 1892. 

+ The description given by Cope of the skull of Hadrosaurus (Diclonius) mirab- 
iis, Leidy, is erroneous in various important points. Among the more serious 
errors are the following: the predentary bone is mistaken for the dentary, the 


dentary is regarded as the surangular and as the splenial, while the squamosal is 
called the parietal. See Proc. Phil. Acad., 1883, p. 97, plates iy—vii. 


Marsh— Restorations of Claosaurus and Ccratosaurus. 845 


The main characters of the vertebral column of Claosaurus 
are well shown in the restoration. There are thirty vertebre 
between the skull and sacrum, nine in the sacrum, and 
about sixty in the tail. The whole vertebral column was 
found in position except the terminal caudals, which are here 
represented in outline. The cervical vertebre are strongly 
opisthoceelian, and the first eleven have short ribs. The 
dorsals are also opisthoccelian. There are no true lumbar 
vertebrae, as the last of those in front of the sacrum support 
free ribs. The anterior caudals are opisthoccelian. The first 
and second have no chevrons. Behind these, the chevron 
bones are very long, indicating a powerful, compressed tail, 
well adapted for swimming. 

In the median dorsal region, between the ribs and the 
neural spines, are numerous rod-like ossified tendons, which 
increase in number in the sacral region and along the base of 
the tail, and then gradually diminish in number and size, 
ending at about the thirty-fifth caudal. These ossified tendons 
are well shown in the restoration, and are of much interest. 
They are not unlike those in /ywanodon described by Dollo, 
but as a rule are more elongate, and appear to lack the definite 
arrangement in rhomboidal figures observed in that genus.* 

The fore limbs are unusually smail in comparison with the 
posterior, and the relative size of the two is well shown in 
the restoration. The scapular arch presents many points of 
interest. The scapula is large, and so much curved that its 
shaft is nearly at right angles to the articular faces of its lower 
extremity. On the anterior margin, above the articulation for 
the coracoid, is a strong protuberance, with a well-defined facet, 
adapted to the support of the clavicle, if such a bone were 
present. The coracoid is very small, and is perforated by a 
large foramen. The two peculiar bones now generally re- 
garded as belonging to the sternum were not codssified. 

The humerus is comparatively short. The radius and ulna 
are much elongated, the latter being longer than the humerus, 
and the radius about the same length. The ulna has a 
prominent olecranon process, and is a stouter bone than the 
radius. The carpal bones were quite short, and appear to have 
been only imperfectly ossified. The fore foot, or manus, was 
very long, and contained three functional digits only. The 
first digit was rudimentary, the second and third were nearly 
equal in length, the fourth was shorter and less developed, and 
the fifth entirely wanting, as shown in Plate VI. 

In the functional digits (II, III, IV), the phalanges are 
elongate, thus materially lengthening the fore foot. The ter- 
minal phalanges of these divits are broad and flat, showing 


* Archives de Biologie; tome vii, p. 249, Gand, 1886. 


346 Marsh— Restorations of Claosaurus and Ceratoswurus. 


that they were covered with hoofs, and not with claws. The 
limb as a whole was thus adapted to locomotion or support, 
and not at all for prehension, although this might have been 
expected from its small size and position. 

The elongation of the fore arm and manus is a peculiar 
feature, especially when taken in connection with the ungulate 
phalanges. It may, perhaps, be explained by supposing that 
the animal’ eradually assumed a more erect position until it 
became essentially a biped, while the fore limbs retained in a 
measure their primitive function, and did not become prehen- 
sile, which was the case in some allied forms. 

The pelvis has already been described by the writer. Its 
most notable features are seen in the pubis and ischium, the 
former having a very large expanded prepubis with the 
postpubis rudimentary, while the shaft of the ischium is 
greatly elongated. 

The femur is long, and the shaft nearly straight. The great 
trochanter is well developed, while the third trochanter is large 
and near the middle of the shaft. The external condyle of 
the distal end is projected well backward, indicating great 
freedom of motion at the knee. 

The tibia is shorter than the femur, and has a prominent 
enemial crest. The distal end is much flattened, and the 
astragalus is closely adapted to it. The fibula is very straight, 
with its lower end flattened and closely applied to the front 
of the tibia. The caleaneum is large, with its concave upper 
surface closely fitted to the end of the fibula. Of the second 
row of tarsals, only a single one appears to be ossified, and 
that is very small and thin, and placed between the caleaneum 
and the fourth metatarsal, nearly or quite out of sight. 

The hind foot, or pes, had but three digits, the second, third, 
and fourth, all well developed and massive. The terminal 
phalanges were covered with broad hoofs. The first and fifth 
digits were entirely wanting. 


All the limb bones in Claosaurus are solid, thus distinguish- 
ing it from Hadrosaurus. The separate ischium, not codssitied 
with the pubis, the absence of a fourth digit in the hind foot, 
and other marked characters, also make the genus distinct 
from Pteropelyx, the skull of which is not known. 


The reptile here restored was nearly thirty feet in length 
when alive, and about fifteen in height in the position repre- 
sented in Plate VI. The remains were obtained by Mr. J. B. 
Hatcher and Mr. A. L. Sullins, in the Ceratops beds of the 
Laramie, in Wyoming. Among the associated fossils are the 
gigantic Triceratops and Torosaurus, which were also herbiv- 
orous Dinosaurs, and with them were found the diminutive 
Cretaceous mammals recently described by the writer. 


Marsh—Restorations of Claosdurus and Ceratosaurus. 847 


Ceratosaurus, Marsh, 1884.* 


In the same horizon of the Jurassic in which Lrontosaurus 
and Stegosarus were found, the skeleton restored in Plate VII 
was likewise discovered. It is a typical carnivorous Dinosaur 
of moderate size, and doubtless was one of the various enemies 
of the large herbivorous forms. The restoration represents 
the reptile one-thirtieth natural size, and in a position it must 
have frequently assumed. . 

The skull of Ceratosaurus nasicornis is very large in 
proportion to the rest of the skeleton. The posterior region 
is elevated, and moderately expanded transversely. The facial 
portion is elongate, and tapers gradually to the muzzle. Seen 
from above, the skull resembles in general outline that of a 
crocodile. The nasal openings are separate and lateral, and 
are placed near the end of the snout, as shown in Plate VII. 

Seen from the side, this skull appears Lacertilian in type, 
the general structure being light and open. From this point 
of view, one special feature of the skull is the large, elevated, 
trenchant horn-core situated on the nasals. Another feature is 
the large openings on the side of the skull, four in number. 
The first of these is the anterior nasal orifice; the second, the 
very large triangular antorbital foramen; the third, the large 
oval orbit; and the fourth, the still larger lower temporal 
opening. 

The parietal bones are of moderate size, and there is no 
parietal foramen. The median suture between the parietals is 
obliterated. The frontal bones are rather short, and are 
closely united on the median line. The nasal bones are more 
elongate than the frontals, and are firmly codssified. These 
bones support the large, compressed, elevated horn-core, on 
the median line. The lateral surface of this elevation is very 
rugose, and furrowed with vascular grooves. It evidently 
supported a high, trenchant horn, which must have formed a 
most powerful weapon for offense and defense. 

The premaxillaries are separate, and each contained three 
functional teeth. The maxillary bones are large and massive, 
as shown in Plate VII. They are provided each with fifteen 
functional teeth, which are large, powerful, and trenchant, 
indicating clearly the ferocious character of the animal when 
alive. These teeth have the same general form as those of 
Megalosaurus, and the dental succession appears to be quite 
the same. Above the antorbital foramen on either side is 
a high elevation composed of the prefrontal bones. These 
protuberances would be of service in protecting the orbit, 
which they partially overhang. 


* This Journal, vol. xxvii, p. 329, April, 1884; and vol. xxviii, p. 161, August, 
1884, 


348 Marsh—Restorations of Claosaurus and Ceratosaurus. 


The lower jaws of Ceratosaurus are large and powerful, 
especially in the posterior part. - In front, the rami are much 
compressed, and they were joined together by cartilage only. 
There were fifteen teeth in each ramus, similar in ‘form to 
those of the upper jaws. 

The cervical vertebrae of Ceratoswwrus differ in type from 

those in any other known reptiles. With the exception of the 
atlas, all are strongly opisthoccelian, the cup on the posterior 
end of each centrum being unusually deep. In place of an 
equally developed ball on the anterior end, there is a perfectly 
flat surface. The size of the latter is such that it can only be 
inserted a short distance in the adjoining cup. This peculiar 
articulation leaves more than three-fourths of the cup unoccu- 
pied by the succeeding vertebra, forming, apparently, a weak 
joint. 
The dorsal and lumbar vertebre are bi-concave, with only 
moderate concavities. The sides and lower surface of the 
centra are’ deeply excavated, except at the ends. All the pre- 
sacral vertebree are very hollow, and this is also true of the 
anterior caudals. 

There are five well codssified vertebree in the sacrum of the 
present specimen of Ceratosaurus nasicornis. The transverse 
processes are very short, each supported by two vertebra, and 
they do not meet at their distal ends. The caudal vertebree 
are bi-concave. All the anterior caudals, except the first, sup- 
ported very long chevrons, indicating a high, thin tail, well 
adapted to swimming. The tail was quite long, and the distal 
caudals were very short. 

The scapular arch of Ceratosaurus is of moderate size, but 
the fore limbs are very sthall. The humerus is short, with a 
strong radial crest. The radius and ulna are also very short, 
and nearly equal in size. The carpal bones were only imper- 
fectly ossified. There were four digits in the fore foot, and 
all were armed with sharp claws. The second and third digits 
were much larger than the first and fourth, and the fifth was 
entirely wanting. 

The pelvic arch of Oeratosaurus is of special interest. In 
the type specimen here restored, the ilium, ischium, and pubis, 
on each side, are firmly coéssified. The ilia, moreover, are 
attached to the sacrum, which was in place in the skeleton. 
The ilia have the same general form as in Megalosaurus. The 
ischia are comparatively slender. They project well backward, 
and for the last half of their length the two are in close appo- 
sition. Their distal ends are codssified and expanded, as shown 
in Plate VIT. 


Marsh— Restorations of Claosiurus and Ceratosaurus. 849 


The pubes have their distal ends codssified, and expand into 
an elongate, massive foot, which is one of the most character- 
istic parts of the skeleton. It is probable that this foot in 
connection with the distal ends of the ischia served to support 
the body in sittmg down. That some Triassic Dinosaurs sat 
down on their ischia is proved conclusively by the impressions 
in the Connecticut River sandstone. In such cases, the leg 
was bent so as to bring the heel to the ground. The same 
action in the present reptile would bring the foot of the pubes 
to the ground, nearly or quite under the center of gravity of 
the animal. The legs and ischia would then naturally aid in 
keeping the body balanced. Possibly this position was assumed 
habitually by these ferocious biped reptiles, in lying in wait 
for their prey. 

The femur is much curved, and the shaft very hollow. The 
tibia is shorter than the femur, nearly straight, and has a large 
cnemial crest. The astragalus is not codssified with the tibia, 
and has a strong ascending process. ‘The fibula is weil devel- 
oped, and nearly straight, its distal end fitting into the eal- 
caneum. The tarsals of the second row are very thin, and 
united to the metatarsals below them. 

The most interesting feature in the extremities of this 
Dinosaur is in the metatarsal bones, which are completely 
ankylosed, as are the bones of the pelvis. There are only 
three metatarsal elements in each foot, the first and fifth 
_ having apparently disappeared entirely. The three metatar- 
sals remaining, which are the second, third, and fourth, are 
proportionally shorter and more robust than in the other 
known members of the Zheropoda, and being firmly united 
to each other, they furnish the basis for a very strong hind 
foot. The phalanges of the hind feet are of moderate length, 
and most of them are quite hollow. The terminal phalanges 
evidently supported strong and sharp claws. 


The unique cervical vertebree, the codssification of the pelvic 
bones, and the union of the metatarsals, as in modern Birds, 
distinguish Ceratosaurus widely from all other Dinosaurs, and 
make it the type of a well-marked family, the Ceratosauride. 
The nearest allied form is apparently Ornithomimus, from the 
Laramie, recently described by the writer. 


The type specimen of Ceratosaurus was about twenty-two 
feet long when alive, and twelve feet high as here restored. 
It was found by Mr. M. P. Felch, in the Atlantosaurus beds 
of the upper Jurassic in Colorado. The associated fossils were 
mainly other Dinosaurs, especially Sawropoda and Ornithopoda, 
together with various small mammals. 

New IlIaven, Conn., September 22, 1892. 


350  Marsh—Restoration of Mastodon Americanus. 


Art. XLU1.— Restoration of Mastodon Americanus, Cuvier ; 
by O. C. Marsn. (With Plate VIIL.) 


THE great abundance and good preservation of the remains 
of the American J/astodon have led to various restorations of 
the skeleton. The best known of these is that made by Prof. 
Richard Owen, in 1846, based upon a skeleton from Missouri 
now in the British Museum.* Another restoration was made 
a few years later by Dr. J. C. Warren, based mainly on a very 
perfect skeleton from Orange county, New York.t This 
skeleton is now preserved in the Warren Museum in Boston. 
A third restoration was made by Prof. James Hall, from a 
skeleton found at Cohoes, New York, and now in the State 
Museum of Natural History, in Albany.t These restorations 
are all of importance, and taken together have made clear to 
anatomists nearly all the essential features of the skeleton of 
this well-known species. 

Additional discoveries have since brought to hght more 
perfect specimens, one of which, now in the Yale Museum, is 
perhaps in the best preservation of any skeleton of the Ameri- 
can Mastodon yet discovered, and this has been used by the 
writer in the restoration, one thirty-second natural size, given on 
Plate VI, which is reduced from a large drawing made for 
the United States Geological Survey. 

The position chosen in this restoration is one which seems 
especially fitted to bring out the massive proportions of the 
animal, and, at the same time, to show nearly all the charac- 
teristic features of the entire skeleton. The animal as thus 
represented was, when alive, about twelve feet in height, and 
perhaps twenty-four feet in length including the tusks. 

This animal was fully adult, as the last molars above and 
below are in place and somewhat worn. The epiphyses of 
the vertebrae, moreover, are nearly all codssified with the 
centra, and in some of them, the sutures are obliterated. The 
epiphyses are also firmly united to the limb bones. 

The tusks were very large, and considerably divergent. 


There were no inferior tusks, and no traces of their alveoli 


remain. The penultimate and last molars are present above 
and below in fine preservation, the former considerably worn. 

Other features of this skeleton, and especially the various 
new anatomical points it discloses, will be discussed by the 
writer in another communication. 

New Haven, Conn., September 23, 1892. | 

* British fossil Mammals and Birds, figure 102, p. 298, London, 1846. 

+ Description of a skeleton of the Mastodon giganteus of North America, plate 
xxvil, Boston, 1852. 

t Report of the New York State Cabinet of Natural History for the year 1867 
plate vi, Albany, 1871. 


‘A. E. FOOTE, M.D., 


4116 Elm Avenue, Philadelphia, Pa., U.S. A. 


A cstamatic Collections for schools, colleges, teachers and students. 
Series to illustrate the physical characters of minerals, their uses in 
the arts, manufactures, etc., etc. 


Illustrated o aogue of Minerals, Mirenalogioal Books, 128 pp., Free. 


RECENT ADDITIONS. 
SCANDINAVIAN MINERALS. 


We have just heard from Prof. Foote, who has spent most of August and part 
of September at the most celebrated localities of Sweden and Norway. Full lists 
will soon be published of his very remarkable collections which place Eudidy- 
mite, Cobaltite, Svabite, Pajsbergite, Kongsberg silvers, Bamle Ensta- 
tites, Ganomalite, Brandtite, Native Lead, Sarkinite, and many-of the rare 
arsenates within the reach of the student. We append an incomplete list of the 


_best minerals obtained: 


Hedenbergite, pues fine Eerie crystals, Sunstone, Orang- 
ite, Thorite (one 4 pound crystal), Kjerulfine crystals (very rare), Talc 
psendomorphs, Rutile, Dahllite, Melanite, Iolite, Euxenite of fine quality, 
groups of Babingtonite, Leucophanite, Monazite and Xenotime crystals, 
Bragite, Columbite, Gadolinite, ‘Keilhauite crystals, Alvite, Vesuvianite 
var., Egeran, Molybdenite, Scapolite, Caryopilite, Flinkite, Pyroaurite, 
Ochrolite, Trimerite, Melanocerite, Barkevikite, Catapleite, Eucolite, 
Hiortdahlite, Homilite, Helvite, Johnstruppite, Lovenite, Meliphanite, 


- WMosandrite, Tritonite, Rosenbuschite, Pyrochlore. 


Perhaps the finest specimen secured is a two hundred pound mass of the 
Greenland Iron which was collected by Baron, Nordenschiold and figured by him 


_in the account of his trip published in 1870. This will form part of Prof. Foote’s 


exhibit at Chicago. 
ENGLISH AND GERMAN MINERALS. 


Full lists of the minerals collected and purchased at the German and English 
localities will-be sent on eppleation: 


MILLERITE. 


A lot recently received from Keokuk, Iowa, contains the most beautiful speci- 
mens of Millerite we have ever seen. The delicate capillary crystals occur with - 
bright and clear Calcite, filling. the cavities and penetrating the surrounding 
erystals. Drawer and shelf Specimens, 25 cts. to $3.00. 


CRYSTALLIZED MANGANOPECTOLITE. 


Numerous shipments from Magnet Cove yielded a few unique groups. The 
crystals are large and in several instances quite perfect. A fresh stock of 
Monticellite, Pseudoleucite, Eudialyte, geniculated Rutile and bright 
Brookites. 


(ee~ Any of the above will be sent on approval. 


We have also received very large additions to our stock of Books, by purchases 
of Libraries, ete., made in Hurope by Prof. Foote and also in America. Our stock 
now is most complete on eyery branch of Science and Medicine. Catalogues free. 
Please mention wat psubiecl you are interested in. 


CONTENTS. 


Art. XX XIV.—On a Color System; by O. N. Roopis se x 263 | 


XXXV.—An Ottrelite-bearing phase of a Metamorphic Con- hee 
glomerate in the Green Mountains; by C. L. Wuirrte. 270 jf 


XXXVI.—Age-Coating in Incandescent Lamps; by E. L. 
INGICHOUG 2 oh Se Bee es era ee A 2 Ih Se =o ee 


XXXVII.—Mica-peridotite from Kentucky; by J. 8. Dicer 286 


XXXVIII.—Glaciation in the Finger- “Lake region of New 
Mork: by. Ds BF. Lincomns@ 2) 2) eee 290 


XX XIX.—Certain Points in the Tinteraetion of Potassium 
Permanganate and Sulphuric Acid; by F. A. Goocu 


and EW. DANNER = 223) 22% =e 301 | 
XL.—Crystallography of the ae Mercurie Halides; by : 

Secb. SP BNETELD: eho ee ee Se a ee Sot 
XLI.—Silver Hemisulphate; by M. C. Lea ._.---_------- 322 


APPENDIX. —XLII.—Restorations of Claosaurus and Cerato- 
Ba: saurus; by O. C. Marsu. (With Plates VI and VII) _ 343 


a Restos of Mastodon Americanus, Cuvier; by 
OC Marsa. ox Wath Plate Vall): 2s ee mre iO). 


SCIENTIFIC INTELLIGENCE.’ 


Geology—Geology of the Taylorville Region of California, J. 8. DItLER: Jura‘and | 
Trias at Taylorville, A. Hyarr: Geological Survey of the State of New York; 
Paleontology, Vol. VIII, J. Haut, 330. —Report of the Arkansas Geological a i 
Survey for 1890, Vol. III, Whetstones and Novaculites of Arkansas, L. 8. 
GRISWOLD, 332. Occurrence of Artesian and other underground waters in ~ 
Texas, ete., R. T. Hitt: Geological Society of America: ee Studies, P. | 

R. UHLER, 333.—Fossil Flora of the Bozeman Coal Field, F. KNOWLTON: 

‘ Paléontologie Végétale (Ouvrages publiés en 1890), R. a 334.—Sylloge 
Fungorum Fossilium hucusque cognitorum, A. MESCHINELHI, 335.—Tronchi di 
Bennettitee dei Musei Italiani, G. CAPELLINI and EH: So~tms-LAuBACH: Ueber 
den gegenwirtigen Standpunkt unserer Kenntniss yon dem Vorkommen fossiler 
Glacialpflanzen, A. G. NATHORST, 336. 


Miscellaneous Scientific Intelligence—American Association for the Advancement of it 
Science, 337.—British Association: Periodic variations in Glaciers: ll 
South Carolina and Canadian Phosphates, C. C. H. Minar, 342. 


NOVEMBER, 1892. 


= AMERICAN. 
| JOURNAL OF SCIENCE. 


ae EDITORS | 
ee D. anp EDWARD &. Us 


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” ioe Proresson: JOSIAH P. COOKE, GEORGE L. GOODALE 
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-ProrEssor GEORGE FP. Be Nes OF Pan spuLenit 


THIRD SERIES. 


VOL. XLIV. [WHOLE NUMBER, OXLIV.) 


No. 263.—NOVEMBER, 1892. 


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—e“— 


THE 


AMERICAN JOURNAL OF SCIENCE 


[THIRD SERIES.] 


eOo 


Art. XLIV.— Unity of the Glacial Epoch ; by G. FREDERICK 
WriGHT. 


A DISTINCTION between upper and lower “ drift deposits ”’ 
had been observed some time before Mr. Croll and Professor 
James Geikie formulated their plausible theory that the ellip- 
ticity in the earth’s orbit was the cause of the great ice age. 
But the publication of that theory with the exceedingly able 
advocacy of two so capable and eminent authorities gave the 
subject such prominence that evidences of successive glacial 
epochs have since been sought for in every land, while much 
of that adduced has been allowed to pass without as close 
scrutiny as would seem desirable. As I have had occasion 
frequently to review much of this evidence both in field 
explorations and in the literature of the subject, it may help to 
a better understanding of the matter to give somewhat fully 
the resuits of my observations and study in this direction. I 
would premise, however, that I shall discuss merely the glacial 
phenomena of the post-tertiary epoch. With the supposed 
evidence of glacial periods in earlier times, this paper has no 
concern except in a very general way. 

At the outset, a question will arise as to what is meant by 
an “interglacial epoch.” The answer to this may show that 
some who discuss the subject are merely considering the mean- 
ing of a word. If every temporary recession of the ice front 
is looked upon as an interglacial period there can be no ques- 
tion that there have been not merely two but a great many 
periods in close succession. But the position of most who 
advocate a succession of glacial epochs is that the continental 


Am. Jour. Scl.—TuHIRD Series, Vou. XLIV, No. 263.—NoVEMBER, 1892. 


352 G. LF. Wright— Unity of the Glacial Epoch. 


glacier retreated, during the interglacial epoch, to such an 
extent that the glaciated area was as free from ice as it is at 
the present time; and that subsequently the conditions were 
repeated and there was a re-advance to nearly the farthest 
limit of the previous movement. It is this view of the case 
which is advocated so vigorously, in this country by Professor 
Chamberlin and some of his associates on the United States 
Geological Survey, and by Professor James Geikie in Scotland, 
Professor Wanschaffe in Germany, Baron De Geer in Sweden 
and others. In discussing the problem it will be natural for 
me to give special prominence to the facts of the American 
field, and, with all respect to individuals mentioned, to the 
discussions and reports of my associates in the explorations of 
this country. But I will not wholly neglect the facts of other 
lands. 

In approaching the subject it is important to notice the fact 
that Professor Chamberlin inaugurated his induction as di- 
rector of the glacial division of the United States Survey by 
publishing a monograph on ‘'The Terminal Moraine of the 
Second Glacial Epoch,” thus assuming the truth of his theory 
in the title. In the introduction to this paper, however, 
nothing could be more indicative of the proper spirit with 
which to enter upon the discussion, or nothing more cordially 
welcoming discussion, than the following remarks : 

“Perhaps no department of geological investigation has 
greater need of careful discrimination than that which deals 
with the complex deposits of the Quaternary age. Most 
formations betray their origin in their salient characteristics, 
but those of the Quaternary age are apparently capable of 
diverse interpretation if their general nature alone is con- 
sidered. It is only by critical discrimination of their special 
and often quite unobtrusive features that they can be deci- 
sively referred to the several agencies that produced them. 
Most formations owe their origin to the action of some one 
dominant agency. The Quaternary deposits are; on the con- 
trary, the product of a combination of agencies, the relative 
work of which is often distinguishable only with difficulty. 
In these discriminations the individual judgment of the inves- 
tigator plays an important part. The influence of personal 
predisposition, therefore, is here liable to be most gravely felt. 
Probably no investigator is entirely free from the influence of 
his own preconceptions and methods of interpretations. He, 
perhaps, does best, who, while duly appreciating these influences 
and assiduously applying checks for their correction, frankly 
submits his methods of interpretation to the correction of 
others.” 


G. F. Wright— Unity of the Glacial Epoch. 353 


That Professor Chamberlin has kept his mind open to 
further light is abundantly evident by comparing his account 
of “the terminal moraine of the second glacial epoch,” in this 
preliminary paper, with that which appears in his later publi- 
cations, while at the same time such a comparison is suggestive 
of possible mistake in his whole interpretation of the facts 
bearing on the duality of the epoch. In this preliminary 
monograph (see pp. 3822-326) the moraine is made to corre- 
spond with the kettle moraine of Wisconsin, and to hug 
the southern shore of Lake Michigan, but in the Seventh 
Annual Report of the U. 8. G. Survey the later glacial drift is 
carried down to Bloomington more than a hundred miles 
farther south, while at the latest date Mr. Leverett (Am. Geol. 
July, 1892, p. 23) specially deputed by Professor Chamberlin 
to look after the moraines, draws his later moraine line one 
hundred miles still farther south, through Litchfield, Hillsboro, 
Pana, Shelbyville, Mattoon, Charlestown, Paris and Terre 
Haute. From other information I have evidence that proba- 
bly this moraine will have to be carried, at least, twenty-five 
miles still farther south to Greenville, which will be less than 
80 miles from the extreme limit of glaciation as determined 
by me. From this it seems not unlikely that in the near 
future the closer observation which has found an exterior 
moraine 200 miles farther south than was at first supposed to 
mark the limit of the second age, may carry it fifty or sixty 
miles farther south still, which would be all that it is necessary 
to make the extreme boundary stand related to the moraine 
there as it does throughout the eastern part of the Mississippi 
Valley. This result is the more likely to occur since for a 
hundred miles or more the whole border of the glaciated area 
in the valley of the Mississippi is so deeply covered with 
less that the determination of moraine deposits is peculiarly 
difficult. Mr. Leverett has already found twelve receding 
moraines in Ohio—the outer one extending to within a few 
miles of the glacial boundary. When as many are found in 
[llinois it will, at the existing rate of separation, carry the line 
as near the border in that State. 

The facts pointing toward a separation of the glacial period 
into two distinct epochs are thus stated by Professor Cham- 
berlin in his monograph on the Driftless Area (pp. 214, 215). 
“The earlier drift is characterized in the interior basin, [1.] by 
a wide but relatively uniform distribution, manifesting only 
occasional and feeble tendencies to aggregation in morainic 
ridges. [2.| It is not bordered, except in rare instances, by a 
definite terminal moraine, but ends in an attenuated border. 
[3.] It is not characterized by the prevalence of prominent 
drumlins or other similar ridged aggregations. [4.] The phe- 


354 G. EF. Wright— Unity of the Glacial Epoch. 


nomena of glacial erosion connected with it are generally 
feeble. Glacial strize are indeed present, even in the periphe- 
ral portion, but the surface of the rock is not usually exten- 
sively planed. [5.] The whole aspect of the deposit indicates 
an ageney which spread the drift over the surface smoothly, 
and relatively gently, with little forceful action. The drainage 
phenomena are also of the gentle order. We have yet failed 
to find evidence of very vigorous drainage connected with the 
older drift of the interior basin except in osars and kames, 
whose conditions of formation were exceptional, but, on the 
contrary, abundant proof of slow-moving waters and imper- 
fect drainage, indicating low slope of the surface. 

“The later glacial epoch, on the contrary, was characterized 
by strong glacial action, planing the rock surface vigorously, 
even up to the very limit of its advance. The glaciers ploughed 
up immense moraines about their edges, except on smooth plains 
whose slope was away from the ice movement. The drainage 
was usually vigorous, and immense trains of glacial gravel 
stretch away from the margin of the ice-sheet, reaching great 
distances down the valleys and frequently filling them to great 
depths with well assorted material. The vigorous action of the 
glaciers of the second epoch and the rapid drainage, in general 
stand in marked contrast with the gentle action and imperfect 
drainage of the earlier epoch. One of the conditions that 
determined the distinction was probably the difference in ele- 
vation that characterized the two epochs. 

“The interval between these two leading epochs we regard 
ag the chief interglacial epoch, representing a greater lapse of 
time and a greater change in the dynamic agencies of the age 
than the several other interglacial intervals, or episodes of de- 
glaciation, which mark the complicated history of the ice age. 

6. “ As belonging to the earlier glacial epoch, we recognize 
two drift sheets that have been described by the geologists of 
the respective states as oceurring in Southwestern Ohio, South- 
ern Indiana, Central and Southern Illinois, Eastern and South- 
ern Iowa, Northern Missouri, Eastern Nebraska, and South- 
eastern Minnesota. 

“ Between these occur, at numerous points, vegetal and fer- 
ruginous accumulations, and other evidences of a non-glacial 
interval. To this horizon belong the larger number of deposits 
described under the term ‘old forest bed, but very many 
vegetal deposits so referred do not, in our judgment, belong 
there, but are referable to several distinct horizons.” 

7. Another supposed proof of a glacial period long preced- 
ing that during which the moraine of the so-called “second 
glacial epoch” was deposited is the greater oxidation of the 
glacial drift south of this moraine. This is prominently men- 


G. F. Wright— Unity of the Glacial Epoch. 355 


tioned by Professor Salisbury as among the features “long 
since recognized by Professor Chamberlin” and which “have 
been made use of by him and his assistants in field determina- 
tion.” (Bull. Geol. Soc. Am., vol. ii, pp. 181, 182. Also An- 
nual Report of the State Geologist of New Jersey for 1891, 
pp. 103-108.) Contrasting the earlier with the later drift as 
seen at Little York, Oxford Furnace, High Bridge and Patten- 
burg (points from three to fifteen miles south of the moraine as 
laid down by the New Jersey Report of 1878), Professor Salis- 
bury says, ‘While the one exhibits oxidatjon, leaching and 
disintegration in an advanced stage of development even “to its 
base, where it is thirty feet thick, the other has not suffered 

oxidation and leaching on any such scale as to make them 
apparent more than two or three feet from the surface, and 
the softest and most easily disintegrated varieties of rock often 
present a degree of freshness which, so far as the eye can see, 
might characterize masses of rock worked out of their parent 
ledges within the memory of living men. We hold, there- 
fore, that this extra-morainie drift represents the remnant of a 
drift covering once much more extensive and more uniformly 
present than now, and that, like the drift in and north of the 
great terminal moraine, it was formed by an ice sheet, but by 
an ice sheet which overspread New Jersey much earlier than 
that which made the terminal moraine and the main body of 
drift, which lies north of it.” (N. J. Ann. Rep. 1891, p. 105.) 
Similar remarks are repeated in even more confident tone in 
the Bulletin of the Geological Society already referred to. 

8. Another indication of the great separation in time be- 
tween the first and the second glacial period, adduced by 
Professor Chamberlin, presents itself in the extent of erosion 
which he supposes to have taken place in the river valleys ex- 
tending southward from the glaciated area, since the upper 
terraces containing glacially transported material were formed. 
(Some Additional Evidences bearing on the Interval between 
the Glacial Epochs, Bull. Geol. Soc. Am., vol. i, pp. 469-480.) 
In the Mississippi Valley the upper terrace assigned by Pro- 
fessor Chamberlin ‘to the first glacial period consists of the fine 
glt or loess deposited on bluffs about 200 feet above the present 
river bottom. Between the deposition of this silt and the sec- 
ond glacial epoch, according to Professor Chamberlin, a trench 
about 300 feet in depth and about sixty miles wide was eroded 
by the Mississippi all the way from Cairo to the Gulf, “ with 
corresponding erosion trenches along the upper branches dur- 
ing the interval between the two epochs” (p. 471). In the 
upper Ohio valley these high level terraces correspond to what 
I had assigned to the effects of the supposed glacial dam at 
Cincinnati. In the valleys of the Susquehanna and the Dela- 


356 G. F. Wright— Unity of the Glacial Epoch. 


ware they correspond to what Lewis denominated the Phila- 
delphia Red Gravel and Brick Clays, and what McGee ealls 
Columbia. 

9. Finally, strong confirmatory evidence of a long inter- 
glacial epoch is supposed to come from the desiccation of the 
lakes which have oceupied the great arid basin in the United 
States west of the Rocky Mountains, of which Lakes Bonne- 
ville and Lahontan are examples. 

Taking up these points in the order mentioned it may be 
noticed— 

1. That on either theory the glacial deposits near the mar- 
gin are the older, and may be a great deal older than those 
farther back. How long the glacial conditions continued is an 
open question, as is also that of how slowly it retreated during 
its various stages, though it probably was pretty rapid as com- 
pared with the advance. Again, it is as much in place for the 
advocate of the unity of the glacial period to suppose a subsi- 
dence in the valley of the Mississippi and elsewhere at the 
time of the climax and during the earlier retreat, coupled with 
a re-elevation towards the close, as for the advocates of duality 
to suppose the same earth movements In connection with two 
periods. Therefore the “relatively uniform distribution ” of 
the marginal drift, may be accounted for on one theory as well 
as on the other. On either theory the marginal drift has been ~ 
longer subjected to erosive and leveling agencies, and, on 
account of the submergence during the climax of the period, 
the deposition of loess has done much to disguise the surface 
features. I can cite a locality near Yankton, S. Dakota, 
where the original irregularity of the morainic drift was com- 
pletely disguised by the superficial water deposits which were 
altogether above the reach of any present stream. Kettle 
holes have there been filled up with silt and were only re- 
vealed in the process of obtaining the sand for commercial 
purposes. At Sarahsville, in Williamson County, Illinois, 
within a few miles of the extreme border of glacial deposits 
there is a section showing ten feet of loess upon the surface 
underlaid by twenty feet of till containing granitic bowlders 
two and a half feet in diameter. (See my report in Bull. Geol. 
Surv., No. 58, p. 71, on Southern Illinois.) Until all that region 
is explored with much more minuteness than it has been so far, 
it is proper to regard the generalizations which are made about 
it with a good deal of allowance for the personal equation of ~ 
the observer. 

2. The fact that the oldest part of the glaciated region “i 
not bordered by a definite terminal moraine, but ends in an 
attenuated border,” is only another way of stating the fact 
which Lewis and I began to urge upon the attention of the 


G. F. Wright— Unity of the Glacial Epoch. 357 


public ten years ago during the early part of our investiga- 
tions. In the map of the “glacial boundary prepared for my 
volume on The Ice Age in North America (p. 175), the legend 
for the line marking the border of the glaciated area west of 
Pennsylvania, is not “ terminal moraine,” but simply “southern 
limit of the ice sheet.” East of that point, indeed, a moraine 
is marked as the boundary, but emphatic attention is called, 
both in my own language and in that of Professor Lewis, to 
the probability that here also an unexplored border of thinner 
glaciated material is to be found south of the moraine. (Ice 
Age, p. 135.) Recent observations enable me to determine 
the extent of this “fringe” as we proposed to call it, in the 
Delaware and Susquehanna valleys, and to give an entir ely dif- 
ferent interpretation to certain facts in that region from that 
proposed by Professor Salisbury in support of his theory of a 
prolonged interglacial period. Of this 1 will speak under No. 7. 
Suffice it here to say that the word “fringe” seems a fair term 
to apply to such a bordering formation whose character is still 
in dispute. Professor Chamberlin’s phrase, “attenuated bor- 
der,” would, however, be equally good. But to insist on eall- 
ing it the drift of the first glacial epoch is to beg the whole 
question in the terms chosen, and tends to serious confusion of 
the public mind as to what the facts really are. The facts are 
well stated in the sentence quoted from Professor Chamberlin. 
But it would seem that occasionally in the discussion inferences 
are mistaken for facts of observation. For example, it is pretty 
generally assumed in the discussion that originally there was a 
much greater amount of drift over the attenuated border than 
there is now and that this has largely disappeared by erosion. 
But there does not seem to be adequate ground for this sup- 
position. A pronounced terminal moraine is by no means a 
necessary result of an ice occupation. ‘The extent of the de- 
posits of till and other morainic material, depends in large 
measure upon the amount of ice movement ‘which has actually 
reached a given point, which, in turn, depends on the time 
during which the front of the ice remained stationary at a 
given point. If there was a gradual approach to a given boun- 
dary and a gradual retreat after a pause of moderate length we 
could not expect a large accumulation of drift. It is toe often 
forgotten that the ice movement diminishes to zero at the very 
border and that for some distance back of the border all the 
effects of the movement are specially feeble. A fringe of 
direct glacial deposit would, therefore, seem to be the normal 
result near the border. By “fringe” is meant an ‘“atten- 
uated border” of direct deposits from land ice such as might 
naturally occur near the limit of an ice invasion. This, which 
was at first supposed to be characteristic only of the Mississippi 


358 G. EF. Wright— Unity of the Glacial Epoch. 


Valley, is now found to be equally characteristic of the region 
a of the Alleghenies. 

The lack of drumlins and other ridged accumulations 
sea the glaciated border need indicate only a small amount 
of ice movement over the region, or a depressed slack condi- 
tion of drainage which, as already stated, may be supposed in 
case of one glacial period as well as of two. 

4, The feebleness of. glacial erosion over the fringe follows 
from the reasons already stated. Of course there was less 
movement over the fringe than farther back. Still that there 
was some vigorous movement close to the very margin is 
shown by the glacial strize which I have reported from Car- 
bondale, [I]. and from St. Louis, Mo. (See Bull. Geol. Surv., No. 
58, pp. 71-73). Dr. Max Foshay has also discovered very pro- 
nounced Ns in Western Pennsylvania in the area coy- 
ered by the fringe several miles south of the moraine as there 
laid down by Professor Lewis and myself. 

5. The fifth point is in part a mere repetition of the first, 
and to some extent the reply will be the same. The slack 
drainage indicated in the deposits near the border was caused 
probably by the changes of level which have been connected 
with the Champlain epoch. A part of this evidence of slack 
drainage is found along the Susquehanna and Delaware Val- 
leys, in the Columbia deposits of Mr. McGee. A natural sup- 
position is that the climax of the period was characterized by 
a depression of land considerably greater than is mdicated by 
the level of the deposits in the Champlain Valley at the time 
of the disappearance of the ice. But as this point involves a 
theory concerning the cause of the period and of the changes 
of level attending it, a few paragraphs may well be devoted 
to a fuller statement of the reasons for believing that a sub- 
sidence may naturally be supposed to have attended the climax 
of the epoch on the supposition that it was single. 

Whatever subsidiary aid the eccentricity of the earth’s orbit 
may provide for the production of glacial conditions, there is 
now little doubt that the ice age was introduced and closed 
by marked changes of level, both in North America and in 
Northern Europe. The fiords which characterize the coast of 
Norway, and which are brought to light by the sounding line 
along both the Atlantic and the Pacific coast of North 
America bear striking witness to the extent of this elevation 
during the period just preceding the glacial epoch. (See 
Appendix to The Ice Age in N. A by Warren Upham.) So 
great was this late Pliocene elevation that it seems to many 
that it might have been sufficient to have produced the glacial 
conditions of the succeeding age even without the aid of astro- 
nomical changes. An elevation of 3,000 feet would probably 


G. F. Wright— Unity of the Glacial Epoch. 359 


be sufficient, and this is much less than we know has occurred 
in central Europe since Miocene times. Miocene shells are 
found on the Alps and Pyrenees at an elevation of more than 
10,000 feet. An elevation of our glaciated region in its 
northern parts of 8,000 feet is therefore not out of analogy 
with the movements during contiguous eras. 

Supposing therefore the elevation of the region south of 
Hudson Bay to amount to 3,000 feet, this would provide the 
conditions necessary for the beginning of an ice age. But 
when such a career is once started it is difficult to imagine how 
it can stop, for the accumulation of ice at once lowers the 
temperature and adds to the elevation of the surface of the 
plateau on which it rests; thus tending to increase the depres- 
sion of the land. The ice piles up and makes an elevation of 
its own, additional to that of the land, and overloads it with 
its own weight. 

_ There is certainly much plausibility in the supposition that 
the subsidence which accompanied the glacial period, and 
from which the continents have not yet fully recovered, was 
in part due to the weight of the ice piled up over the glaciated 
area. ‘The conditions were then unique in the geological 
history of the earth. About 4,000,000 square miles of terri- 
tory in the northern part of North America and about half 
that amount in. Northern Europe were covered with ice aver- 
aging, probably, three-quarters of a mile in depth, making in 
all 5,500,000 cubic miles of ice whose weight had first been 
abstracted from ocean beds, thus relieving the pressure there, 
and then centered over a restricted area at the north. The 
relative extent of this disturbance of equilibrium can be 
appreciated only by comparing this mass of ice with the solid 
contents of that portion of the continent which is above ocean 
level. The mean elevation of North America above the sea 
is estimated by Wallace (Island Life, p. 205) to be 748 feet, 
while the total area is less than 9,000,000 square miles. This 
would give about 1,300,000 cubie miles of land in North 
America above the water level, as against 3,000,000 cubic 
miles of ice over the northern half of the continent during 
the climax of the glacial period. Taking the specific gravity 
of the rocks as two and a half times that of ice, the total 
weight of ice piled up over British America and the Northern 
United States, at the time referred to, was nearly equal to 
that of the whole land surface of the continent which is above 
sea level. That this enormous change in the distribution of 
weight and pressure on the surface of the earth should occur 
without any effect on the configuration of the globe is difficult 
to believe. When therefore we find that extensive changes in 
level seem actually to have been correlated with this loading 


360 G. EF. Wright— Unity of the Glacial Epoch. 


and unloading of the strata which took place during the pro- 
gress of the glacial age, it is not a wholly unwarranted step in 
reasoning to connect the two as cause and effect. The sup- 
position, therefore, of a marked subsidence of the northern 
part of the continent contemporaneous with the climax of 
the period is a fair one to use in explanation of the complex 
phenomena of the time. 

To appreciate the degree of probability attending the ex- 
planation, however, it is important to consider still more 
closely the natural operation of the forces at work. Upon 
doing this it is evident that glacial conditions would continue 
some time after the land subsidence had begun. For a long 
period the accumulation of ice might be faster than the sub- 
sidence of the plateau on which it rested. The anticlimax, 
when the melting began to proceed faster than the accumula- 
tion, was doubtless reached only after a very prolonged period. 
But when the tide of affairs had really turned and the land 
had begun to rise the melting of the ice had also progressed 
to a great extent and the final ending up of the period and 
the return of the land to a higher level doubtless proceeded 
with great relative rapidity. On this provisional hypothesis 
most of the facts indicating slack drainage during the deposi- 
tion of the marginal deposits will be as readily explained as 
on that of two distinct epochs with different attitudes of land 
level during their existence. 

6. The occurrence of vegetal and ferruginous accumulations 
between successive strata of glacial deposits, has long attracted 
wide attention. At first these were taken to indicate inter- 
glacial periods of wide extent and of long separation in time. 
The occurrence of such deposits seems to be still the chief 
reliance of many European geologists, as well of some in this 
country, for belief in successive glacial periods. Professor 
Chamberlin, however, is not among those who place undue 
reliance upon this class of evidence, as the quotation from him 
already given shows; for in his judgment very many of the 
vegetal deposits occurring in the till “are referable to several 
distinct horizons.” The hazard of inferring a prolonged inter- 
glacial epoch from such deposits, also very forcibly appears in 
view of some recent facts brought to light by study of the 
glaciers of Alaska. 

In this Journal for January, 1887 (pp. 11 to 15, more fully 
stated in The Ice Age of N. A., pp. 51-62), I have given the 
facts concerning certain buried forests at the mouth of the 
Muir Glacier which are standing in undisturbed strata of sand 
and gravel, from which the ice is slowly withdrawing. I 
adduced evidence also to show that the ice front had with- 
drawn several miles during the present century, uncovering 


G. F. Wright— Unity of the Glacial Epoch. 361 


forest beds on its way. These inferences have been fully con- 
firmed by the investigations of Professors Reid and Cushing 
who spent the summer of 1890, on the same ground (see Na- 
tional Geographic Magazine for March, 1892, and The Ameri- 
ean Geologist for Oct., 1891). Indeed Professor Reid’s photo- 
graphs show that the ice front had receded 3,000 feet during 
the four years intervening between our visits and he is con- 
fident that the glacier has receded fourteen miles during the 
century. These observations reveal also unexpected rapidity 
in the movements of great glaciers and remarkable capacity of 
ice in certain conditions to creep over unsolidified strata of 
sand and gravel without disturbing them. From the rapidity 
with which both forests and ocean fauna follow up a retreat- 
ing ice front where, as in this case, it debouches into an arm 
of the sea, it is clear that two or three centuries are sufficient 
to produce a forest bed of considerable extent with all its 
accompaniments of glacial deposits below and above. 

In addition to this Mr. Russell (National Geographic Maga- 
zine, vol. ili, p. 92, Am. Geologist, March and May, 1892; 
and this Journal, March, 1892) reports from the great Mala- 
spina glacier, whose foot spreads out over an area of 1,500 
square miles on the low lands southeast of Mt. St. Elias, that 
on the belt of morainic accumulations which conceal the ex- 
treme margin of the glacier for a width of five miles or more 
there is a dense forest growth. This forest has every appear- 
ance of considerable age. It consists principally of spruce 
trees, some of which are three feet through, but there are 
many alders “and a great variety of shrubs and bushes, to- 
gether with rank ferns which grow so densely that one can 
scarcely force a passage through them.” (This Journal, p. 
178.) In many places this vegetation is on a moraine which 
is underlaid by ice not less than a thousand feet in thickness. 
These forests appear also on the north border of the glacier. 
The whole area of ice observed by Mr. Russell to be covered 
by forests was estimated at from twenty to twenty-five miles. 
Such facts as these should make us hesitate about attributing 
every forest bed buried in glacial deposits to a distinct glacial 
period. In the complicated movements which doubtless at- 
tended the advance and retreat of so vast an ice sheet there is 
room for the burial of a great many forest beds, and Professor 
Chamberlin is doubtless correct in thinking that those discov- 
ered in the Mississippi Valley may belong to several different 
horizons. In my “Ice Age” (pp. 484-488), I have quoted at 
length from the late Mr. Lesquereux to show that two or three 
hundred years is ample time to allow for the accumulations of 
peat which have been found embodied in glacial deposits. 
(See also Penn. Ann. Geol. Report for 1885, pp. 106 to 114.) 


362 G. L. Wright— Unity of the Glacial Epoch. 


From the discussions in the International Congress of Geol- 
ogists at Washington in 1891, it would appear also that a fair 
share of the European members did not regard the interstrati- 
fied gravel deposits of North Germany as indicative of any- 
thine more than atemporary oscillation of the ice. (See Am. 
Geol. Oct., 1891, pp. 241 to 247.) The “interglacial shell 
beds” at elevations of 1,000 and 1,400 feet above sea in 
England at Macclesfield and Moel Tryfaen, have been shown 
to be shells pushed up from the Irish Sea, and washed out and 
stratified in thin beds by the local streams of water accom- 
panying the departure of the ice sheet. (See my paper in 
this Journal, Jan. 1892; but especially Professor Kendall’s 
comprehensive discussion of the evidence in my volume just 
published by D. Appleton & Co., entitled Man and the Glacial 
Period, pp. 186-182.) Professor Lewis’s conjecture seems to 
be amply sustained by subsequent investigations. The evi- 
dence for a succession of glacial periods in Great Britain is 
inconclusive, while the evidence against it is overwhelming. 
Professor James Geikie has indeed recently returned to the 
defence of his favorite theory (see On The Glacial Period 
and the Earth Movement Hypothesis, being a paper read 
before the Victoria Institute, London), in which he relies 
almost wholly upon evidence of successive glacial periods to 
prove that the astronomical theory, to which we have referred, 
is the only adequate cause. His evidence is largely drawn 
from interglacial beds on the continent of Europe containing 
remains ot plants and animals. The strongest instance ad- 
duced by him is still that of the interglacial lignite beds of 
Diirnten and Utznach in Switzerland. But it would seem 
that the inference of great oscillations of climate which he 
draws from the character of the vegetation composing the 
lignites rests upon very uncertain data. The remarks of Pro- 
fessor Prestwich upoa the deposits are of great weight : : 

“ Admitting the fact that the Diirnten Lignites rest on beds 
of undoubted glacial (ground moraine) origin, and that the 
trees grew on the spot where their stumps and remains are 
found, it by no means follows, as contended, that because 
these trees are all of species now living in Switzerland that 
the temperature was as high as that of Switzerland at the 
present day. Zhe Pinus sylvestris, Abies excelsa, the Yew, 
the Birch, and the Oak, flourish equally in Sweden and far 
north in Siberia, and there is an absence in the scanty Dirnten 
flora of those plants which, while having a more southern 
range, also now live in Switzerland. On the other hand, there 
is there one species of Pinus (P. Montana) which is spread 
over the mountain country up to heights of 7,000 feet, and is 
rare in the lowlands, while one of the mosses in the lignite i is 


G. F. Wright-— Unity of the Glacial Epoch. 363 


closely allied to a species now growing on the hills of Lap- 
land. The few species of mammalia have a distinctively arctic 
facies. The Hlephas primigenius, EF. antiquus, the Ursus 
speleus, and even the Cervus elaphus and Los primigenius, 
are commonly associated with Reindeer, Musk-ox, and other 
aretie animals of cold post-glacial times. Further, both the 
trees and animals are those of our ‘forest bed,” the last land 
survival before the climax of the glacial period. 

“Ts the return, therefore, of the retreating glacier,—sup- 
posing the boulder gravel above the lignites of Diirnten to be 
due to direct ice action,—to be ascribed to anything more than 
a comparatively slight temporary change of climate, like those, 
only more marked, that now for a succession of seasons cause, 
from time to time, a temporary advance of the glaciers? We 
must allow, of course, for greater differences, and possibly 
longer intervals of time than now obtain.” (Geology, vol. il, 
pp. 458, 459.) 

I have elsewhere called attention to the semi-arctic facies of 
the vegetation found in our own interglacial beds. (See Ice 
Age in N. America, pp. 482-496.) . 

7. The supposed proof of the great age of the marginal 
deposits drawn from their superior oxidation, is partly an illu- 
sion of observers and partly a normal result of the fact that 
the continental glacier moved over a region which was at the 
start deeply covered with oxidized material derived from the 
long secular disintegration which had preceded. The results 
of this secular disintegration are abundantly evident every- 
where south of the glaciated area, especially over the regions 
containing granitic and gneissoid rocks. For scores and some- 
times for hundreds of feet in depth these rocks are frequently 
so disintegrated by the long continued percolation of water 
charged with acids, that the mass is as loose in texture as a 
gravel bank. (See especially “On the Formation of Bowlders 
and the Origin of Drift Materials” by L. 8. Burbank, in Proe. 
Bost. Soc. Nat. Hist., Nov. 19, 1873; also a paper by Professor 
Pumpelly, in this Journal, 1879, pp. 13-14. A valuable sum- 
mary of discussions upon this important point is given by Mr. 
Ralph 8. Tarr in the American Geologist for July, 1892.) 
Naturally the material first and farthest moved by the ice 
would be this which was already well oxidized to begin with. 
To this cause there can be little doubt is to be ascribed the 
oxidized character of the material contained in the “ fringe ” 
and of that composing the Philadelphia Red Gravel and Brick 
Clay, which is the overwash of the ice sheet when it was at its 
climax and when the drainage was sluggish from the differen- 
tial northward depression which characterized that portion of 
the period. 


364. G. F. Wright—Unity of the Glacial Epoch. 


The extensive oxidation spoken of by Professor Salisbury 
in the quotation made from his recent reports on the glacial 
deposits of New Jersey, is clearly of preglacial origin. In 
company with Professor A. A. Wright (a very competent 
geologist and mineralogist who is familiar with the region de- 
scribed by Professor Salisbury) I have, during the past sum- 
mer, gone over the field pretty thoroughly so as to complete 
work which the late Professor Lewis and I had contemplated 
before his death. The area is that occupied by the southern 
part of Morris county and the northern part of Hunterdon 
county, New Jersey, and Northampton county, Pennsylvania. 
These counties border the Delaware River below the terminal 
moraine as delineated by the New Jersey geologists in 1878 
and by Professor Lewis and myself in 1880 and 1881. Until 
recently this moraine has stood as the southern boundary of 
the glaciated region, and has been regarded as a place where 
there was no fringe and where the glacial moraine of what was 
called the ‘second glacial epoch” coincided with that of the 
first. It is fair to say, however, that this part of our work 
was done by Professor Lewis and myself at the outset of our 
attempts to trace the glacial boundary and that we then shared 
with others the supposition that the boundary was everywhere 
marked by a distinct terminal moraine. 

But in the progress of our work we had our attention called 
more and more to an attenuated border which we called the 
“fringe” and which I have attended to almost exclusively in 
my later explorations of the boundary in the Mississippi Val- 
ley. In commenting upon this fringe Professor Lewis (see 2d 
Penn. Geol. Surv. Rep., vol. Z, p. 201) remarks that traces of 
this “fringe” may be looked for in Pennsylvania and New 
Jersey, and that the impression had grown upon him “that 
this fringe is destined to play an important part in glacial 
geology.” Professor Lewis’s early death prevented his follow- 
ing out the clues already then in mind, and I have been unable 
until the present season to examine the region with sufficient 
care to enable me confidently to say anything about it. Never- 
theless, in view of what Mr. McGee has been writing about the 
Sousa re deposits I ventured three ‘years ago to utter a warn- 

o, and to suggest that he might be drawing some unwarranted 
a elueioins from the facts he was presenting, in view of the 
probability that some of his facts belonged to the fringe which 
Professor Lewis and I had overlooked in that region. (See Ice 
Age in N. A., p. 135.) I am now able to demonstrate that 
both Mr. McGee and Professor Salisbury have been led astray 
in their recent publications by their failure to notice some of 
the characteristics of the “ fringe” in the Delaware valley. 


G. F. Wright— Unity of the Glacial Epoch. 365 


The true glacial deposits in the Delaware valley below the 
Water Gap can be readily traced by the distribution of Medina 
sandstone which forms the crest of Blue Ridge, rising every- 
where as a solid wall about 1,000 feet above the country to 
the south. This is a very characteristic and enduring rock, 


Del. Water. <7 | | - 
(aE, 
ENE 
se SSN 


Siegen 
rsbuty ESE VAY 


: 
° 


S25) Terminal Moraine 

of 7 Atrias Shale ¥ Sandst 
CE JOneda ¥med Sandst | | Elevations 
(COD Shale ¥ Slate refer To 
[-7 JTL Satur Limestones 
KNN Gretssoia Rocks 


Map of the Delaware valley in the vicinity of the Terminal Moraine. 


and forms a large part of the moraine in the counties men- 
tioned. South of the moraine, on the New Jersey side of the 
Delaware, within a distance of fifteen miles, there are three 
low mountain ridges (Scott’s, Pohatcong and Musconetcong) 
separated by valleys. These ridges and valleys run northeast 
by southwest parallel with Blue Ridge. The mountains con- 
sist of gneissoid rocks, and are evidently the remnants of three 
anticlinals which were once covered with strata of Lower Silu- 
rian limestone and Hudson River slate, remnants of which ap- 
pear both in the hollows between the ridges and on both the 
north and their south flanks of the ridges as a whole. South 
of Musconetcong Mountain stretch the Triassic red shales 
which cover so much of the central part of New Jersey. But 


366 G. EF. Wright— Unity of the Glacial Epoch. 


in this portion of the state there has been absolutely no trans- 
portation of northern material out upon the Triassic shales, 
showing that no glacial movement here ever passed Muscon- 
etcong Mountain. 

These Archean ridges everywhere exhibit remarkable effects 
of secular disintegration. Gneissoid bowlders are creeping 
down their sides in all directions of slope, and, in favorable 
places for observation, the rock is seen to be disintegrated toa 
great depth. Many cuts show that the softer material is wash- 
ing out and working down toward the valley, and leaving 
the harder masses to follow at a slower rate. Doubtless 
the original height of the mountain has been thus reduced 
thousands of feet, thus entirely removing the covering of 
lime and slatestone. We have here now but the cores of 
the original ranges. But guided by the material trans- 
ported by what we may call the Delaware River lobe of the 
ice sheet, we find that in the vicinity of the river the ice 
actually overran Scott’s Mountain as far east certainly as 
Bethel, and left Medina bowlders in considerable numbers in 
the Pohateong Valley near Washington. The actually trans- 
ported material here cannot be distinguished in its oxidation 
from that in the moraine north of Oxford Furnace. The oxi- 
- dation of which Professor Salisbury speaks at Oxford Furnace 
and Little York is the secular oxidation which we have 
described as characterizing the whole mountain. But with 
this local material at the places mentioned there is mingled on 
the surface a considerable deposit of the northern rocks 
belonging to the fringe. The ice here barely went over 
Scott’s Mountain to Washington. It did not here cross Po- 
hatcong Mountain so as to reach Musconetcong Mountain. 

Nearer, the river, however, it crossed the low Pohatcong 
ridge also and, at one point, about five miles south of Philips- 
burgh, reached a col in Musconetcong Mountain, landing 
there a good many Medina bowlders, and allowing some of 
them to be carried down a small streamlet on the south side 
which for a time offered an outlet for the drainage in that 
direction. That the ice did not extend farther is shown by 
the fact that there is absolutely no transported material out on 
the Triassic rocks beyond the influence of this little stream, 
and in the case of that, the Medina pebbles have all worked 
down towards the Delaware River. 

On the west side of the Delaware, below the moraine, 
there is a similar extension of the phenomena of the fringe; 
as there is also in the Valley of the Susquehanna below Ber- 
wick. To obtain the sections of these river valleys given by 
Mr. McGee to prove a subsidence in that region of several 
hundred feet during the Columbia (Philadelphia Brick Clay) 


G. F. Wright—Unity of the Glacial Epoch. 367 


period (see this Journal, vol. exxxv, pp. 876-879) he has cer- 
tainly gone above the boundary of the fringe, and confounded 
direct glacial deposits with those made by the flooded streams 
of the period. : 

At Pattenburg and High Bridge there are cuts in deposits 
which at first look very much like true till, and they have been 
adduced by Professor Salisbury as unquestionable instances ot 
its occurrence at these points, which demonstrate by the oxida- 
tion its great age. But a fact which Professor Salisbury failed 
to notice would seem to be fatal to his theory. There is no 
foreign material in the cuts; at least Professor A. A. Wright 
and I could not findany. All the fragments of the rock found 
in them are from the strata which have demonstrably been in 
place in the mountain, and may have worked down in the 
course of the slow disintegration to which it has been subjected 
since the beginning of Mesozoic time. An additional proof 
of this is that there is a significant cessation of Medina bow!l- 
ders before reaching the north side of Musconetcong Moun- 
tain in the vicinity of both these places. There are, it is true, 
in the deposits many pieces of slate which are scratched as in 
true till, and very rarely there is a bowlder of gneissoid rock 
which shows faint scratches on some of its faces. But in all 
these cases it is impossible to tell whether the scratching has 
been done by an ice movement or by land slides and by the 
slower process of “creep,” which is everywhere going on in 
the region. In both these places the mountain in close proxim- 
ity rises several hundred feet above the deposits, and bowlders 
are creeping down from them. Taking the whole situation 
into view it seems far more probable that these deposits are 
the product of the degrading agencies at work in wearing down 
the mountain than that a northern ice sheet should have sud- 
denly ceased to deposit Medina bowlders upon reaching the 
vicinity of this mountain, unless the ice ceased to move any 
farther. If there had ever been any such amount of Medina 
sandstone mingled with local material as is found in the moraine 
at Oxford, or at Little York, no lapse of time could have elim- 
inated it. For this sandstone is far more enduring than the 
slate of which there are so many fragments both at High 
Bridge and Pattenburg. The evidence relied upon by Pro- 
fessor Salisbury from the excessive oxidation of these deposits 
is thus seen to be illusory. He has misread the facts. 

8. The most weighty considerations favoring the duality of 
the glacial period are found under the eighth head. Yet 
it is more than possible that the apparent conclusiveness arises 
from an incomplete comprehension of the facts which con- 
fessedly are of a very complicated character, and but imper- 
fectly known. 


AM. JouR. Sci.—THIRD SERIES, VOL. XLIV, No. 263.—NoveEmMBER, 1892 
25 


368 G. EF. Wright— Unity of the Glacial Epoch. 


In the present state of evidence as made known to the 
general scientific public it is difficult to discuss the progress of 
events since the beginning of the glacial period in the lower 
Mississippi Valley. But according to Professor Chamberlin 
what is called the Orange Gravel and has heretofore been 
regarded as of glacial age,is preglacial. It does not contain 
oranitic pebbles. His study of the deposit also convinces him 
that it was originally continuous over the entire trough which 
has a width of about sixty miles (Bull. Geol. Soe. Am. p. 471). 
The only relic of the earlier glacial deposits which he would 
recognize over this area is the silt which everywhere caps the 
Orange Sand and extends beyond it to the east. This he 
would connect with the lcess in the upper part of the valley 
extending to the moraines. Apparently he does not regard 
this silt as a deep water deposit but as a deposit spread out over 
a vast flood plain when the drainage was slack both from a de- 
pression northward and from the previous filling up of the 
trough by the Orange Sand. But granting that this is the cor- 
rect interpretation of the phenomena, it is difficult to see how 
the erosion is shown to be ‘‘interglacial.” If that depressed 
condition of things ocenrred at the climax of the period, why 
may not the erosion simply gauge the time since that climax? 
I will, however, leave others more familiar with the facts to 
discuss the various assumptions underlying the argument from 


~ the Lower Mississippi, and turn to the problem of erosion and 


deposition in the valley of the Ohio River of which I have 
more personal knowledge. 

‘In brief the facts are that the Ohio occupies a trough, from 
three to five hundred feet in depth and averaging from a 
half mile to a mile in breadth, which has been eroded from 
nearly parallel strata of Paleeozoic time. Nor does the present 
depth of the trough represent the whole extent of erosion. 
The channel is filled with gravel to a depth of from fifty to 
a hundred feet or more below the low water mark. Two 
sets of terraces containing granitic, and therefore glacial, drift 
mark this trough all the way from Louisville to the head-waters 
of the Allegheny River up to a level between 1,000 and 1,100 
feet above tide. ‘The lower terrace is continuous and is definitely 
traced up all the northern tributaries to the terminal moraine 
and is much higher and coarser near the moraine, and wherever 
tributaries come into the Ohio from the glaciated region, than 
it is below. ‘This terrace rises at its highest points to about 
120 feet above low water mark, that being the height at Cin- 
cinnati and at the mouth of Beaver Creek in Western Penn- 
sylvania. Evidently the channel was at various places origin- ~ 
ally filled up to this height so as to raise the water level by 
that amount all the distance above Cincinnati. — 


| 


G. F. Wright— Unity of the Glacial Epoch. 369 


The second series of terraces connected with the glacial 
period occur in various oxbows and on numerous shelves of 
rock bordering the channel at elevations of from 200 to 300 
feet above the present river level and at about 1,000 feet above 
tide. Two of the best known localities are Bellevue abont 
five miles below Pittsburgh, and Parker about thirty miles up 
the Allegheny from Pittsburgh. 

The glacial terrace at Bellevue is 300 feet above the river, 
and is supported by a shelf of rock about one half mile wide. 
At Parker the glacial deposits are in a deserted oxbow of the 
river formed when the level was 200 feet higher than now. 
Up the Monongahela River there are corresponding terraces to 
which Professor I. C. White has called attention which are at 
about the same absolute level, and entirely above the regular 
river terraces which have been formed in process of the lower- 
ing of the channel. One of the chief differences between 
these high-level terraces on the two rivers is that those on the 
Allegheny have granitic pebbles derived from the glaciated 
region while those on the Monongahela do not. Professor 
White describes extensive areas where this mantling of what 
seems like a lacustrine deposit, consisting of pebbles, and de- 
posits of clay sometimes thirty feet thick, containing fresh 
leaves, characterizes the Monongahela up to a level of from 
1,000 to 1,100 feet and there suddenly cease. 

Professor Chamberlin maintains that these high-level ter- 
race deposits are merely the remnants of flood plains when the 
whole drainage level was at that elevation. Asa corollary to 
this he contends that the drainage level was at that height at 
the time of the first glacial epoch, admitting of the distribution 
of the granitic pebbles in the Allegheny drift, and that the 
erosion of the Ohio gorge below that level (i. e. to a depth of 
about 250 feet for a distance of about 1,000 miles as the water 
runsy was eroded during the interglacial epoch. To that first 
epoch he would also attribute the glacial deposits on the south 
side of the Ohio opposite Cincinnati which I had adduced as 
rendering it probable that there was an ice dam across the 
river at that point. Professor Chamberlin, on the contrary, 
supposes these deposits to have been made so much earlier than 
those a short distance north of Cincinnati that the interval is 
marked by the whole erosion of the gorge of the Ohio through 
its whole extent. 

I was not present at the discussion of the Cincinnati ice dam 
at the Geological Society a year ago. But, from what has been 
published since, it is evident that the last word has not yet been 
said about it. Mr. Leverett in particular has attempted to corre- 
late some of the clay and leess deposits in southeastern Indiana, 
with deposits of similar character in Illinois, attributing both to 


370 G. F. Wright— Unity of the Glacial Epoch. 


the earlier glacial period during its slackened drainage. But he 
does not seem to have duly considered the facts which I have 
presented making probable an obstruction of the channel of the 
Ohio near Madison, Indiana, in Jefferson and Ripley Counties 
which might well account for the facts in that part of the 
state most like those in Southern Ohio. (See Bull. U.S. Geol. 
Sury., 58, pp. 65, 66.) Something more than similar microscop- 
ical results must be relied on to demonstrate chronological 
identity of deposits. 

The theory of a somewhat prolonged obstruction of the 
channel at Cincinnati by ice has received strong confirmation 
in Professor James’s investigations, going to show that the pre- 
glacial channel of the Ohio ran at Cincinnati still farther north, 
following up the valley of Mill Creek until it jomed the Big 
Miami near Hamilton. At any rate it is certain that the Ohio 
did not in preglacial times flow in its present channel from 
Cincinnati to the mouth of the Great Miami, for I am in- 
formed by Mr. Charles J. Bates, inspector of masonry for the 
Cincinnati Southern Railroad whose bridge crosses the river 
just below the city, that bedded rock was found by him a few 
feet below the present bottom of the river extending across its 
whole width. But at Hamilton in the valley of the Miami 
where the depression of Mill Creek joins it, the rock bottom 
is as much as ninety feet below the level of the bottom of the 
Ohio at Cincinnati. This northern bend of the river in pre- 
glacial times adds greatly to the argument from direct evidence 
of a prolonged ice dam there. The gorge for several miles 
below Cincinnati is comparatively narrow and. its erosion in 
good part may perhaps measure postglacial time. 

In all this discussion it should be borne in mind that we 
cannot assume an absolutely constant level of the land in the 
region of the Upper Ohio Valley. Indeed, the subsidence 
proved by the Champlain deposits to exist at the close of the 
ice age involved a differential in the depression of the land to 
the north which is very suggestive, while another class of facts, 
equally suggestive of considerable changes of level in connec- 
tion with the glacial period, appears in the northerly slope of 
the bed of many northern tributaries of the Upper Ohio and 
Allegheny rivers. The Shenango, Mahoning and Beaver 
rivers, and French, Oil and Conewango creeks, all have a rock 
bottom which slopes to the north, or away from their present 
outlets. Mr. Carll and some others have argued from this 
that there must have been a system of northern outlets into 
Lake Erie in preglacial times. (2nd Penn. Geol. Surv. i, pp. 
330 to 866.) The actual existence of such northern outlets 
has, however, not been proved by direct evidence. The theory 
of a general elevation of the country to the north in preglacial 


G. F. Wright— Unity of the Glacial Epoch. 371 


times, such as is supposed to have brought on the period would 
seem to provide a natural explanation. But Mr. Leverett, 
under guidance of Professor Chamberlin’s theory of the course 
of events in the Upper Ohio is compelled to resort to the 
hypothesis that a part of this lowering of the channels of these 
streams to the northward was done by subglacial currents of 
water forced by hydraulic pressure to run up hill to find exit. 
(See this Journal, Sept. 1891, p. 209.) A theory driven to such 
extremities cannot be said to be altogether free from difficulty. 
A simple statement of the rival theory concerning the course 
of events in the Upper Ohio Valley is its own best defence. I 
suppose that the erosion during early Tertiary times had pro- 
ceeded so far that base levels had become established, and that 
the rock shelves at Bellevue and Parker mark the flood plain 
of the river at that time. During the close of the Tertiary 
period the land underwent elevation until it stood much 
higher than now over all the northern part of the United 
States and Southern Canada. During this time the rivers 
lowered their beds to the extent shown by their present rock 
bottoms. The channel of the Ohio was a product of that 
period. The differential northerly elevation permitted the 
erosion of the northern tributaries of the Ohio spoken of. 
Their present attitude is the result of subsequent differential 
subsidence. This subsidence occurred ‘in connection with the 
climax of glacial conditions when the ice extended so as to dam 
up the Ohio at Cincinnati. This dam codperated with the 
slack drainage attending the differential subsidence to produce 
many of the phenomena which Prof. Chamberlin attributes to 
a first glacial period. Floating ice came down the Allegheny 
River in great quantities and drifted into the oxbows and 
upon the shelves of the earlier epoch of erosion, and left the 
glacial material which is found in such places as Parker and 
Bellevue. Similar conditions in the Monongahela favored the 
deposits of pebbles and silt at the high levels described by Pro- 
fessor I. C. White. The deposits in Teases Valley between the 
Kanawha and the Ohio in West Virginia probably belong to 
a somewhat later stage when the barrier below Cincinnati had 
been worn down to a considerable extent. For it should be 
observed, that the preglacial channel of the Ohio at Cincinnati 
toward Hamilton was permanently closed by glacial deposits. 
The Columbia terraces of the Susquehanna and the Dela- 
ware were deposited under somewhat similar conditions. 
There was a depression of the coast level of about 200 feet in 
New Jersey allowing the great ice rafts loaded with Medina 
bowlders which came down the river to tide level to be floated 
over the lowlands of the state south and east of Trenton, and 
to be stranded along the shore on the west side of Philadelphia 


372 G. EF. Wright— Unity of the Glacial Epoch. 


to a height of 175 feet. The subsidence to the north was so 
much greater than that at the south that the drainage of these 
rivers was much slacker than now, but nowhere do the terraces 
of this period on the Delaware and Susquehanna rivers.extend 
much above 175 feet except inside the region actually covered 
by glacial ice. How much these rivers have lowered their 
beds since that time it is difficult to tell, but probably not a 
great deal. 

I cannot well close this part of the discussion without refer- 
ence to a recent attempt of Professor Winchell (Am. Geolo- 
gist, Aug. 1892, pp. 69 to 80) to measure the length of the 
interglacial epoch in Minnesota. Professor Winchell presents 
strong evidence to show that the preglacial channel of the 
Mississippi above St. Paul ran in a nearly straight line with the 
lower valley and reached the present valley again seven or eight 
miles north of Minneapolis. This he supposes to have been 
filled up during the first glacial epoch, while in the interglacial 
epoch the channel that has long been known west of Minneap- 
olis was eroded, to be filled on the advance of the last glacial 
ice sheet. This amount of work he estimates would not have 
required more than 9,750 years, which would be the length of 
the interglacial epoch in that latitude. Though this is as 
nothing to the length of the period as estimated by Professor 
Chamberlin for the southern part of the glaciated area, it is 
sufficiently long to make us ask whether the data are sufficient 
by which he would establish the different ages of those pre- 
glacial channels? The aspect of the unglaciated areas where 
secular erosion is open to inspection is such as to throw much 
doubt over surface indications in the glaciated region. I 
should be inclined, therefore, to wait for further light before 
committing myself unreservedly to the theory in question. 

9. The final consideration bearing on the duality of the 
glacial period is drawn from the successive enlargement and 
desiccation of Lakes Bonneville and Lahontan, in the arid 
basin west of the Rocky Mountains. This coincidence is 
certainly very striking, and the theory that there is a causal 
connection between the phenomena of the glacial periods and 
the enlargements of these lakes is very plausible. But in our 
general ignorance of the causes of local climatic changes such - 
a coincidence should not go far in face of other evidence. 
There are, for example, successive salt deposits in many regions 
which indicate local variations of climate equal to anything 
which can be demonstrated in the great Rocky Mountain 
Basin, but in geological periods when we have no reason to 
suspect glacial conditions. That the last enlargement of Lake 
Bonneville coincided with the glacial period is pretty certain, 


G. F. Wright— Unity of the Glacial Epoch. 373 


but that there were glacial periods to accompany the earlier 
enlargements is by no means so evident. 

Futhermore, as bearing against the duality of the glacial 
period it may ‘be urged with great force that it is improbable 
that two periods should so nearly duplicate one another as 
these two are supposed to have done. To those who maintain 
the sufficiency of Croll’s astronomical cause, however, this is 
rather an argument in favor. But on the other hand, that 
cause would also demand a long succession of periods during 
all the geological ages, and of these we lack sufficient proof; 
while it would throw the two periods which Professor Cham- 
berlin recognizes back much farther than the facts will admit. 
It must be “said, however, that it is not wholly out of analogy 
with known earth movements to suppose that there has been, 
in connection with the glacial period, a succession of oscilla- 
tions of the earth’s crust nearly duplicating each other. Such 
oscillations seem to have occurred in various geological ages, as 
for instance during the coal period when the successive coal 
beds were formed. And indeed, much can be said in favor of 
the view that such an oscillation, when once begun would per- 
petuate itself. The loading of one part of the land surface 
and its consequent subsidence would naturally, if not neces- 
sarily, be attended with the elevation of other and perhaps 
distant portions of the crust. This might secure the beginnings 
of a glacial period in another hemisphere, which when fully 
grown, would return the favor, and by its weight cause the 
earth’s crust to bulge out again ‘where ‘it had been depressed. 
But our knowledge of these matters is too vague to reason on 
it with any confidence, as is also that of the other causes 
which have been suggested for the production of the phe- 
nomena of the period. 

In conclusion it is sufficient to remark that our present 
state of knowledge on the subject seems so imperfect that it 
is not conducive to success in investigation to hold any theory 
as to the unity or duality of the period with great positiveness. 
Over-confidence on this point at the present time is likely to 
blind the eyes of the investigator, and to hinder progress, 
both in the collection and in the interpretation of the multitu- 
dinous and complicated facts which everywhere invite our 
close attention. 


374 C. B. Thwing—Photographic Method of 


Art. XLV.—A Photographie Method of Mappers the Mag- 
netic Field ; by CHARLES B. THWING. 


THE common method of obtaining a cross section of the 
field of force of a magnet by means of iron filings is very 
satisfactory when only 1 temporary representations of the field 
are desired. There has been wanting hitherto a suitable 
method of making a permanent map of “the magnetic field. 

A method employ ed in the physical laboratory at North- 
western University has been found to give results so far 
superior to any hitherto obtained, that a ~ deseription of the 
method employed will probably prove of value to others who 
may be engaged in the study of the magnetic field. 

While studying the magnetic field, it was suggested by Mr. 
John Lamay that a permanent record of the tield could be 
obtained by securing a map upon blue print paper, exposing to 
the sun, and washing as usual. The results obtained were 
beautiful ; but it was of course necessary to repeat the process 
for every copy of the field desired. It at once occurred to the 
writer that by employing a photographie dry plate, in place of 
the blue print paper, a negative would be obtained from which 
any desired number of prints could be made and which would 
have the additional advantage of representing the figures in 
their true colors. 


Fig. 1. Apparatus employed. 


The apparatus employed is shown in fig. 1, which also illus- 
trates the method used in distributing the iron filings and 
exposing the plate. 


Mapping the Magnetic Field. 375 


For obtaining the field of a bar magnet, the magnet was 
placed upon a large card, previously marked with concentric 
circles and parallel lines to facilitate the centering of the mag- 
net. The photographie plate was placed, film side up, directly 
upon the magnet. The iron filings were held at a distance of 
a foot above the plate in a bag of loosely woven flannel, from 
which, by shaking the bag, they could be evenly distributed 
over the surface of the plate The plate was then held at two 
points and tapped gently until the filings had arranged them- 
selves along the lines of foree. The room was, of course, up 
to this point illuminated only by non-actinie light. The ex- 
posure was now made by turning the key of an incandescent 
lamp, supported at a convenient distance directly above the 
center of the plate. The position of the lamp is a matter of 
considerable importance, as the light from a gas jet at one side 
of the plate will cause the filings to cast a shadow and give an 
incorrect representation of the lines of force. Where an 
electric lamp is not convenient, nearly as good results may be 
obtained by holding a lighted match above the plate. It is 
more difficult, however, to time the exposure correctly by this 
method, and the match will often so cast a shadow upon the 
plate as to cause irregularity of illumination. After exposure, 
the plate is tipped so that the filings may slip off, and the few 
which still cling to the surface of the film are carefully re- 
moved by means of a fine, camels-hair brush. The negative 
is then developed and fixed in the usual way. 

The plates employed should be of a sort to give the strongest 
possible contrasts. A slow plate such as Carbutt’s process 
plate was found to give most satisfactory results. This plate 
required an exposure of twenty seconds, when a sixteen-candle 
power lamp was placed at a distance of eighteen inches from 
the plate. If a match is employed to illuminate the plate, 
Carbutt’s B 16 may be used, with an exposure of about three 
seconds, and nearly as good results wil] be obtained. 

For making prints from these negatives, any paper may be 
employed which will give good black and white tones. I have 
found the aristotype paper to give beautiful results when 
printed deeply and toned to exactly the right point Reduced 
positives from these negatives make very brilliant lantern 
slides, by means of which a great variety of magnetic fields 
may be shown to a large audience. The want of such lantern 
slides for illustrating popular lectures has been felt by the 
writer and doubtless by many others. 

Figures 2 to 5 show typical forms of the field of a bar mag- 
net. To obtain the best results, the bar magnet should be a 
strong one and of considerable size, since the film is of neces- 
sity placed the thickness of the glass plate away from the 


376 C. B. Thwing—Photographic Method of 


magnet, and with a weak magnet the lines will not be sufli- 
ciently distinct; especially since it is necessary to employ a 


considerable quantity of the iron filmgs in order to make a 
brilliant negative. 


<= A . ay 
ROS AX { 
SS SA 


i 2 
by) He as = SS 
eee Daf iH ; “| AX SSS 


Fig. 2. End of Bar Magnet. 


Fig. 6 was made on a 5 by 8 plate with a four inch horse- 
shoe magnet. 


‘A (og BA Ky 
y ee 


i We Uh 


W 
y 


a Lae 


Fig. 3. Bar Magnet. 
In fig. 7, six similar eight inch square bar magnets were 
employed, and placed with alternate poles toward the center. 
This is the arrangement commonly employed in the fields of 


an alternating dynamo; and the figure gives a very good idea 
of the lines of force in such field. 


Mapping the Magnetic Field. 377 


In the preparation of this plate, a marked distinction was 
noticed between the north and south poles of the magnets. 
This difference is fairly well shown in the cut. 


VEEP Ty AS 
SR a od 
\ ay \ hy 
1. $1; i/ 


if AH} 


Wy 


ji N 4a Pt y . 
44 x2 ' 4 yeh ye phy . N u 
LOB BAY AE E&Y 
SEF fe) Hay PIS SAA ERA AW oN A AX 
5 ae a ay gure \ 
FM RA He SN ANS 
; Ranituny 

’ 


= ae A SEAN 
Fig a hPy py rhs 


Fig. 4. Unlike Poles. 


The alternate poles beginning with the pole upon the left 
of fig. 7 are south poles. The filings in the neighborhood of 
these poles are in every case more erect and exhibit greater 
intensity of action than those at the north poles. Whether 
this is due to a real difference between the north and south 


Fig. 5, Like Poles. 


poles of the magnet or is to be explained as a mere coincidence, 
can only be determined by more careful observations than 
those which I have yet made. 


378 C. B. Thwing—Photographic Method of 


Figure 8 is a representation of the field of a dise magnet, 
made by magnetizing a small circular slotting-saw of 24 
inches diameter and #th of an inch thickness. The lines of 


Beet ad NS CUT SERIAL AE TTB TTT 7 77 Ne hace ge 
‘ willy A thf ad tp Py ee 
Wy AAW } = 
\ Ny Wig iN A 
\) 


twit} 


ni ( ; 


lca ay vi $ 
hy ie uy cl 
SAN A 


sen tete 


Fig. 6. Horseshoe Magnet. 


force bear a striking resemblance to some drawings of the 
solar corona, and may suggest the correct explanation of that 
but little understood phenomenon. 


LEN NYY ENN 
Pe — a AN fz : ~ 


aN 


SS. 


Alternate Poles. 


The remaining figures illustrate sections of fields of various 
forms of electro-magnets. 

Figure 9 is a section of the field of a small motor of the 
closed field type, and resembles quite closely the field of the 


Mapping the Magnetic Krield. 379 


dise magnet shown in fig. 8. The leakage indicated by the 
lines at the right of the figure is due to the iron base upon 


which the fields were mounted. ; 
SAAT PUTAS AWN ES ee 
SSRN NW ae 


Nant ( Yojza~ 
NN NR i ( as 
NENA AW v 
SSE Lge 


Fig. 8. Disc Magnet. 


Figure 10 is the field of a small motor of the common horse- 
shoe type. 


ae 
aa 


bh) 

ase I dt det 
wi ee Ar alan NIE i Toe 
Ay ne tht ge ae Bes 


% 
FY 


APN (Gera! 


rR Gea 
hy 


yong 


a 


‘\ 
i OG 
{ SEN wes 
JEXRRRAARSSESS 


\. WS = 
ANRC REESE 


Both figures 9 and 10 were obtained by removing the arma- 
ture and one bearing so as to make it possible to place the 
plate within a short distance of the field, at right angles to the 
armature shaft. 


380 C. B. Thwing—Photographic Method, ete. 


Interesting figures might be obtained by inserting rings 
between the poles similar in form to the rings of which the 
armature is composed. ‘These figures illustrate a large class of 


TTYL SOY. 
segs VG. 
es, : “ fo : Z ‘7 


Voy 


TES 


Ny bp pF SSS SSS UST EN TUPI 
DE eS 


Fig. 10. Motor-Field—Horseshoe Type. 
very instructive maps which might be made of the various 
types of magnetic fields now in use. A careful study of a 
set of such figures should afford valuable suggestions to the 
designer of field magnets and transformers. 

The motors used in Figures 9 and 10 are shown with the 
bearings removed in figure 1. 


Fig. 11. Hlectro-Magnet. 


Figures 11 and 12 represent the field above the poles of the 
small electro-magnet shown in figure 1. 


Genth and Penfield—Contributions to Mineralogy. 381 


In. figure 11 the filings in the regions near the poles are 
drawn to the poles, leaving those regions bare. 


<\¥ 


Fig. 12. Electro-Magnet—Iron Chippings. 


The somewhat fantastic field shown in figure 12 was ob- 
tained from the same electro-magnet by employing coarse iron 
chippings, instead of the finer iron filings used in the remain- 
ing figures. The position of the bits of iron parallel to the 
lines of force is distinctly shown. 


Note.—Since preparing the above, my attention has been called to the excellent 
article of Professor Houston in the Electrical Engineer for July 20th, in which a 
method exactly similar to the one here described was briefly outlined. This 
furnishes another instance of the simultaneous invention of a process by two 
investigators, each working wholly without knowledge of what the other is doing. 


Arr. XLVI.— Contributions to Mineralogy, No. 54; by 
F. A. GentH. With Crystallographic Notes; by 8. L. 
PENFIELD. 


1. Aguilarite. 


SINCE the publication of my investigations on aguilarite,* 
I had an opportunity to examine quite a number of specimens 
of this mineral. Only a very few small fragments of pure 
aquilarite in skeleton dodecahedrons, like the original, were 
found among them; most of them were altered, as previously 


* This Journal, xli, 401. 


382 Genth and Penfield— Contributions to Mineralogy. 


described. 
short notice. 

a. One variety in irregular flat particles between the cleavage 
cracks of calcite or calcite and quartz, with a hackly fracture 
and iron black color had the composition of nearly pure agui- 
larite (@). 

b. A second variety made up of small capillary needle- and 
wire-shaped individuals without any distinct planes, also 
ininute rounded particles, all forming an irregular spongy 
mass of an iron gray color and metallic luster. Between this 
are small crystals, not over 5™™ in diameter, apparently hexag- 
onal and much resembling forms of polybasite, produced by 
twinning. The material for the analysis (6) was selected with 
great care, but, as the results show, gave the composition of 
aguilarite, slightly contaminated with a sulphantimonide. 


There were several, however, which deserve a 


a. b. 

Ag a a a 79°41 80°27 * 
SS ee eee epee 5°93 6°75 
See tee net AP eeeRy 13°96 W2e7/33 
Cues. Sasads Tee 050 0:07 
| CY ei Seah ei eed ad home AOA 0°26 
Sloe oretievies teu arty. eek: 0°41 

99:80 100°49 


c. Similar erystals, as mentioned under 6, were found on 
quartz, associated with calcite, some of them were over 10™™ 
in diameter. On examination with a lens they could easily be 
seen to be made up of different minerals and were evidently 
the result of the alteration of aguilarite into stephanite, as 
previously described, with metallic silver, argentite, ete. The 
outer portion was brittle, the inner malleable—but neither 
could be obtained in a state of purity. They gave: 


Malleable portion. - 
84:05 or Ag._-. 25°28 


Brittle portion. 
Agee Ge S Ol NOES sO 2cSo mae Ae: 


S>-cct 


Cue arG83 AoiSesarl6:35) Cues mise Ag... 55°49 
He_=) 0°42 CUSeee ey onlin ak Cvs reese Ag,Se - 14.28 
Sb. 6°83 eS 2 nee s0;0 Gee SDias Same oe Cus 22) ie 
BRR ah) Ene SMweheee IDO, VAN aie CRBS) SiS. 2 alae 
See sol Spe ui eee SO" Se Sem SO! As.S,-- 0°46 
Sela 76 eee Bese Seana S13 niet ie one 

99°93 98°59 99°98 100°00 


These crystals had been considered to be a new species. 

d. In the lot of aguilarite specimens was noticed a small 
piece of quartz and calcite with solid dodecahedral crystals, 
mostly distorted, from 1-2™™ in size. As there was no indica- 


Genth and Penfield—Contributions to Mineralogy. 383 


tion of any cavernous crystals I thought they aeeht show a 
different composition. 


The analysis gave: : Calculated : 
PA rete ae NTS 84°40 Age eae 85°06 per cent. 
Cities. ae 0°49 De suns THEO Sen onc’ 
Seema eS ye ailynt 11°36 Sent i ue 3°91 Ms 
Se (by diff.) ....- 3°75 ; 
100:°00 
100-00 


This is the composition of argentite in which 4 of the 
sulphur is replaced by selenium. The composition correspond- 
ing to: gAg,Se4 {Ag,S is given above. 

é. A specimen of acanthite trom Guanajuato, Mexico, pre- 
sented to me by Messrs. Geo. L. English & Co., was analyzed 
for the purpose of seeing whether it contained selenium, but 
was found to be entirely free from it. 

Elongated, wirelike distorted crystalline particles in calcite. 
The analysis gave a trace of quartz and calcite and— 


99°99 


2. Metacinnabarite. 


To Professor Gustav Guttenberg of the Central High School 
at Pittsburg, I am indebted for an interesting occurrence of 
metacinnabarite in irregular particles of from 5 to 10™™ in 
diameter, disseminated through a ferruginous, laminated barite, 
from San Joaquin, Orange ‘County, California, where it had 
been collected by one of his pupils. 

Color iron-black, but many pieces show already a partial 
change into ordinary cinnabarite, both by a good lens and the 
reddish black powder which some of,the particles yield on 
pulverizing. Fracture conchoidal, brittle, soft. Sp. gr. 7-706. 
The analysis gave : 


Elomi emia me ice 85°89 
SIR Se NIA hI 13°69 
LO Miia She ee 0°32 

99:90 


It is remarkable that all the fragments which were examined 
showed the presence of chlorine. The 0°32 per cent of Cl 
which were found would indicate’ an admixture of 1:23 per 
cent of calomel. 


Am. Jour. Sci.—THIrRD SERIES, VOL. XLIV, No. 263.—NoveMBER, 1892. 
26 


384 Genth and Penfield—Contributions to Mineralogy. 


3. Léllingite. 


The arsenide of iron from Halyburton’s and Drum’s farms 
which, from qualitative tests, had been mentioned in my 
Minerals of North Carolina,* as leucopyrite, was found to be 
Jéllingite. 6 

A specimen from Drum’s farm, Alexander County, mostly 
oxydized into scorodite, ete., yielded some very pure frag- 
ments of from 4 to 6™™ in size. They did not show any erys- 
talline faces, apparently amorphous; fracture conchoidal. Sp. 
er. 7031. The analysis gave: 


SGU a Ones ee rae eg 70°83 
Guys ee a ee eat race 
DN U emer eas Ree gan 27°93 
hs eRe eee ee Py oO ne NY Coe Osa 
99°52 

4, Rutile. 


The flesh-colored orthoclase from West Cheyenne Cajfion, 
El Paso Co., Colorado, contains minute black erystals which 
were identified by Professor Penfield as rutile. 

From the specimens received by Messrs. Geo. L. English & 
Co. it appears that these crystals are rarely in contact with the 
orthoclase, but generally implanted in the more recent quartz, 
resulting from its alteration and filling its cavities. 

The rutile crystals are from 0°5 to 4™™ in size. 

The forms which have been observed on them are a, 100, 2-2 ; 
m, 110, 1; 2, 130, 2-8; e, 101, 1-¢ and s, 111, 1. Some of the 
erystals are like fig. 1, a habit which is not common with 


rutile but reminds one rather of cassiterite. Many of the erys- 
tals have four of the pyramid faces, s, larger than the others 
and developed apparently into monoclinic prisms. Fig. 2 rep- 
resents one of the distorted crystals in ordinary projection and 
fig. 3 is a basal projection’of another, with a still more pro- 


* The Minerals of North Carolina, by Frederick Augustus Genth, Bulletin No. 
74, U.S. Geol. Survey, Washington, 1891. 


Genth and Penfield—Contributions to Mineralogy. 3885 


nounced prismatic habit. They are iron-black. Sp. gr. 
4-249. ~The analysis gave, after deducting O07 per cent of 
quartz : 


SH OAGee ceils ol eee 1°40 
TSO NSAP ars a ee iy it 91°96 
CON ae ce ore bua 6°68 

100°04 


5. Quartz resulting from the alteration of the flesh-colored ortho- 
clase of W. Cheyenne Cavion. 


The orthoclase crystals become rounded and in their decom- 
position leave cavities which are partially filled with grayish- 
white porous and cavernous coatings either directly upon the 
orthoclase or with some space between, filled with earthy 
limonite. The pure grayish or slightly greenish white material 
shows a cryptocrystalline structure, dull or witha faint vitreous 
luster. H.=85 Sp. gr.=2°552. 

In appearance it somewhat resembles some varieties of the 
so-called damourite. 

The analysis gave: 


OMT ON ee eee mel | OME 
SiG olan een GLa 96°63 
INTO aC co eee earam feyl 0°93 
Jahn Yip Ne lls ara 0°85 
IN aOR Oe alan ey trace 
EGG et eile eee a 0°46 

99°82 


from which it is evident that it is quartz, slightly contami- 
nated with orthoclase. 

In the same orthoclase is a mineral in very fine and minute 
needle-shaped crystals of a greenish yellow color which could 
not be identified for want of material. 


6. Danalite. 


Among some specimens from W. Cheyenne Cajon, El Paso 
County, Colorado, which were given to me for identification 
by Messrs. Geo. L. English & Co. were two fragments, one of a 
erystal 15x17™™ in size, the other not showing any erystalline 
form. both were discolored by iron and manganese oxides 
and were found to be an interesting variety of danalite. 


386 Genth and Penjield—Contributions to Mineralogy. 


4, The fragment is part of a modified tetra- 
hedron, having the forms 0, 111, 1; 0’, 111, 
—1 and d, 110, z, fig. 4. One of the dodeca- 
hedral faces is larger than the other two 
and, as it makes a right angle with the large ° 
tetrahedral faces adjacent to it, it gives the 
erystal the appearance of being part of a 


modified cube. 

No cleavage has been observed ; fracture uneven, splintery 
to subconchoidal, color of some portions pale rose color to 
brownish, owing to slight oxidation. Sp. gr.= 3-626 to 3°66L. 
Luster vitreous. 

The material used for analysis was purified by digesting 
with very dilute hydrochloric acid and had a fine pale rose 
color, like a deeply colored rose quartz. The mean of two 
closely agreeing analyses is as follows: 


Mol. ratio. 
Tenition 225.45 .- 0:21 
SiO, Wi Sie IN REN A 30°26 Sipe 4a 504 2°93 
BeOie nee tee 12°70 1B So E70 500 
CuO ie ees ee 0°30 Giisssae O24 “004 
TAT © Nepean I Be can 46°20 Janene Dayo 570 b 1:187 6:90 
De O paler eal a ies 6:8 Men). 5:37 00CK| 
MnO veers sense 22 Mines 10295 ‘017 J 
Sens nie eters 5°49 ND 1:00 
103°19 
Less O forS ..- 2°78 
100°4] - 
LON etal ap i as 35°04 2°78 32°26 2°016 Wile 


closely agreeing with the formula: 
(Be, Zn, Fe, Mn),Si,0,,8 


Associated with quartz, astrophyllite and a mineral which 
appears to be new. 


". Yttrium-Calcium Fluoride. 


On some of the quartz associated with astrophyllite was a 
mineral in granular crystalline particles. Some fragments 
show reflections from cleavage planes. White, grayish white 
and reddish white. H.=4. Sp. gr.=4:316. 

In the analysis of the best fragment which I could get, a 
little over one gram, the mineral was decomposed by sulphuric 
acid, by which the fluorine was expelled as HF! and the little 
silica as SiFl,. The analysis gave: 


Genth and Penfield—Contributions to Mineralogy. 387 


Calculated as 


fluorides. Molecular ratio. 

lomitions 4 s=i4e= 1°57 
oe Wi) ROeS) See aco 8 58°05 317 

CeO ee apas a2 a. 0°83 0°96 005 + ‘331 I, 
(ai); Ore ese cal: 5 1:86 009 
CaOrr ai ine 19°41 27°03 347 1 
Fe,O, and other admixtures 

not det. 89°47 


This gives the formula CaF, . (Yt,Er,Ce, La, Di)F,. 


8. Altered Zircon or Cyrtolite. 


Messrs. Geo. L. English & Co. sent me for identification 
crystalline groups of about 10 to 15™"™ in size. They consisted 
of bundles of crystals of columnar structure, radiating from 
a center with their prismatic planes mostly obliterated and 
terminated by rounded planes of the common pyramid of 
zircon. 

They were stained with a greenish brown coating of the 
oxides of iron and uranium, and, for purification, had to be 
treated with dilute hydrochloric acid after which the color is a 
very light greenish gray. Sp. gr. = 4°258. 

Associated with muscovite, flesh-colored orthoclase and 
quartz, at Mt. Antero, Chaffee Co., Colorado. 

The analyses gave : 


a b. 

Pe mitionys se ene 2°42 2°47 
SiO, Ap he ME eA IR ES SA 30°38 30°66 
LOGE To Es ea ee Hes 61°38 60°89 (by diff.) 
Mii On Sere Rs, 0°60 0°65 
os OM aie 70:70 0°63 
UO, BNE Sah olen a eT OR ay 4°82 4°70 
MnO, MeO; CaQe ss: traces traces 

100°30 100°00 


9. Lepidolite. 


A very beautiful variety of \lepidolite, associated with albite 
and quartz, from Tanagama Yama, Japan, has been received 
from Messrs. Geo. L. English & Co. It occurs in erystal- 


* The molecular weight of Yt and Er was found to be 126. The oxides were 
yellow and the sulphates and oxalates slightly rose-colored. Although these 
results are somewhat unsatisfactory, on account of the contaminated condition 
and small amount of the material at my command, I thought them of sufficient 
interest, to place them on record, as great pains were taken to arrive at the most 
perfect separation of the constituents. Should it be my good fortune to get 
larger quantities of this mineral, I intend to repeat this investigation. 


388 Genth and Penfield—Contributions to Mineralogy. 


line plates from 80 to 80™™ in size. Professor Penfield says: 
The form of the plates was not determined. The clear por- 
tions show a biaxial interference figure with wide divergence 
of the optical axes, about like muscovite. 

Color grayish white, slightly pinkish, luster vitreous to 
pearly. Sp. gr. = 2°883. B.B. it fuses readily to a .brown 
glass, coloring the flame intensely a deep red. The analysis, 
being the mean of two or three determinations, gave : 


SiO sites Ante ae gen oy ae 53°34 
NO Bi nme ee 17°76 
Biehl ee esta) a ae Capa een eR SED 
ud Ao @ epee MU Oh i ON welll 
Mo Os. so 45. Ae oe ee 0:05 
CaO ee MORc Brie” Wei ee 0°37 
TPiiOpaserg sae yaaa 4°60 
INtan ON eo pe iad i aa 1:55 
1 GN @ eee ge diet eens ne ay 10°90 
BUM O 3) S Meab oe ey ane eee Seg pee BN (OAG5) 
BE LDS aes igh OMe ce) ed ee 7-78 
103°02 

WessiO tor tle se oreo 8°28 
99°74 


The lepidolite plates were all more or less coated with 
minute brownish white scales, which appeared to be a product 
of the alteration of lepidolite. With great difficulty I picked 
out 0°2563 grm. of pretty pure material which gave : 


LOL Fe Nene Mees sere iat eas oe 52°91 
ATR OR se ev Oe te ek Serene 
HolOa se ein pu deg Mee NS 50 
MnO We joan eters ee ee 0°94 
yD GU fe ee Meech ANE ted toro TL) 
Jomition=se ee Se hye 5:97 
BUS KeAOm Na Ovetc a = see not det. 


Therefore not cookeite, but lepidolite altered by hydration. 


10. Fuchsite. 


In a peculiar mica schist, consisting of a gray muscovite 
with quartz in Habersham County, Ga., occurs associated with 
chromite and interlaminated with gray muscovite a deep emer- 
ald green mica in scales, sometimes from 10—12™™" in diameter. | 
Professor Penfield writes me about it as follows: “The fuch- 
site does not show crystalline outline and the scales are small 
for optical examination. I observed the following. The sec 


Bedell and Crehore 


Liffects of Self-induction, etc. 389 


tions show a biaxial interference figure, the divergence of the 
optical axes being large, about like muscovite. The cleavage 
plate shows a decided pleochroism, for rays vibrating parallel 
to ¢ bright chrome green, and parallel to § yellowish green. 
Speyer — 2-060. 
The analysis gave: 


Tonitionys Sees Seba las 6°04 
SiOi vee ol aerial): 46°73 
INI Oe eee en te se Gn, 99°00 
Orpen DESL I Nae, Oras eee 2°73 
| SSA O en aur Ain ge tie ea 2°59 
Ns Om esate nS 3°03 
CUO eee eee 0-14 
DN at O) gee ees we toe 2 hee a 0:26 
KR O Dire ey rae sta Won OCAD 

99°77 


Chemical Laboratory, 111 8. 10th St. 
Philadelphia, August 29th, 1892. 


Art. XLVII.— The Hffects of Self-induction and Distributed 
Static Capacity in a Conductor ; by FREDERICK BEDELL, 
Ph.D., and ALBERT C. OREHORE, Ph.D. 


THE solution obtained by Sir Wm. Thomson for the varia- 
tion of the current and the potential at different points in a 
conductor possessing static capacity is given by Mascart and 
Joubert, L’Hlectricité et Le Magnétisme, vol. i, § 238, and is 
treated at length by Mr. T. H. Blakesley in his book on Alter- 
nating Currents. The object of the present communication is 
to give the solution for the case of a conductor possessing self- 
induction as well as distributed capacity, and to note the effects 
produced by the introduction of the self-induction. 

The rate of change of the charge on an element of the cable 
is equal to the difference of the currents flowing into and out 
from it; and so, writing g for charge and z for current at any 
time, and w for the distance of any point from the origin— 
positive direction being that of current flow—we have 


em Vide 
If e is the potential of an element, its charge is g = Cedz, 


where C denotes the capacity per unit length of the cable, and 
the first equation may be written 


390 Bedell and Crehore—Lffects of Self-induction 


de di 
(1) jaivi esl nneT 

By Ohm’s law the current in an element is equal to the 
total EH. M. F. (the sum of the impressed and that of self- 
induction) divided by the resistance; and, if R is the resis- 
tance per unit length and we assume the back E. M. F. of self- 
induction per unit length to be equal to the rate of change of 
the current multiplied by a constant L, we may write 


(F de-L 5 de) 
(2) fairy Tes 


In some cases this assumption may approximately represent 
the true effect of self-induction, and the results obtained from 
this particular assumption may show the nature of the effect 
of self-induction even in cases where the assumption is not 
justifiable. 
The differential equation for potential is obtained by elimi- 
nating 2 from (1) and (2) and is 
de de de 
ip + UGE - — RC ap 
The current equation, obtained in the same way, is similar 
when z is written instead of e. 
The general solution of these equations is 


R 
ce me 
hk ? 
noes (t—Cka) 
pce hi a: 


h,k 


where ¢ is the Naperian base, and / and & are constants to be 
determined. 

If the impressed E. M. F. is harmonie, and at the origin 
e=E sin wt, where w denotes angular velocity, the solution 
for the potential at any point of the conductor at any time 
becomes - 


(3) e = Ee *?” sin (cot + az). 


The solution for the current at any time across any section of 
the conductor is 


= Ca +P% y 
(4) t= py, sin (o + ax + tan Z| 
a/ Im. a 


and Distributed Static Capacity in a Conductor. 391 


In these equations Im. denotes the impedance, (R*+L’w*)* ; 
Og = Ole. = aaa BaD 
p= Vee VIm.—L@; anda aie Im. + Loo. 


The solutions in equations (8) and (4) show that the poten- 
tial and current are propagated in harmonic waves whose am- 
plitudes decrease with the distance from the origin according to 
a logarithmic decrement. At any point of the conductor the 
potential and current vary as simple harmonic functions of the 
time ‘with constant amplitudes which are different for every 
point of the conductor. The current wave is propagated in 
advance of the potential wave by an angle @ such that 


tan 0 = z This phase difference diminishes with increase of 


frequency when there is self-induction, but becomes a constant 


angle of 45° when L=0. The wave length is A and the 


rate of propagation is =. The wave length and rate of propa- 


gation each become less as the self-induction increases. The 
wave of higher frequency will have the shorter length and be 
propagated the faster. This difference in rate of propagation 
of waves of different frequencies is most marked when there 
is no self-induction. 


1 
The distance at which the amplitude decreases to = th of its 


nee 1 Aight 
va pln tan 0” w tan @ 
The rate of decay is most rapid when there is no self-induc- 
tion. The waves of higher frequency decay more rapidly 
than those of lower frequency; when there is no self-induc- 
tion this difference in the rate of decay is the greatest. 

The difference in the rates of propagation and decay of 
waves of high and low frequency doubtless constitutes the 
limitations to the use of the telephone. As the several har- 
monic components of a complex tone advance along the con- 
ductor, they keep shifting their relative phases according to 
the difference in their rates of propagation, and also change 
their relative intensities according to the difference in their 
rates of decay, thus changing the resultant combination tone 
and materially altering its quality. These effects are always 
present in circuits containing distributed static capacity but 
are not so marked when there is also self-induction. 


the time for the decrease is 


Physical Laboratory of Cornell University, July, 1892. 


392 Gooch and Phinney—Quantitative Determination 


Arr. XLVIUI.—TZhe Quantitative Determination of Rubid- 
tum by the Spectroscope; by F. A. Goocu and J. LI. 
PHINNEY. 


[Contributions from the Kent Chemical Laboratory of Yale College—XVIII.] 


In a recent paper issued from this laboratory* the possi- 
bility of determining small amounts of potassium quantita- 
tively by means of the flame spectrum was demonstrated. 
The work which we are about to describe was performed in 
the endeavor to see how far similar methods might be appli- 
cable to the quantitative determination of rubidium. It was 
shown in the former work that hollow coils of platinum wire 
may be adjusted to hold definite amounts of liquid and that, 
by taking care to plunge the coil while hot into the liquid and 
to remove it from the liquid with its axis inclined obliquely to 
the surface, it is possible to take up constant amounts through 
a long series of experiments. It thus becomes possible to 
bring ‘definite amounts of any soluble substance into a flame to 
be viewed spectroscopically. The potassium salt best adapted 
to spectroscopic use proved to be the chloride, and it was 
found to be advantageous to dry the coils over a hot radiator 
before introducing them into the flame. A large Muencke 
burner gave the best sort of flame, an ordinary single prism 
spectroscope provided with an adjustable slit (the width of 
which we were able to fix by closing it upon wires of known 
diameter) and an observing telescope moveable so that different 
portions of the spectrum might be shut out at will, served 
sufficiently well for the work. The coils were made of No. 28 
platinum wire (0°32™™" in diameter) wound in about thirty turns 
to a spiral 1° long by 2™™ in diameter and twisted together at 
the ends to form a long handle. With the apparatus described 
it was found possible, under the most favorable conditions, to 
recognize ae characteristic red line of the potassium spectrum 
when only =/;75 mg. of potassium, in the form of the chloride, 
was brought to the flame. It appeared, furthermore, that a 
comparison of the brightness of two spectra produced in close 
succession could be made with all the accuracy to be antici- 
pated in photometric measurements, and that therefore by 
gradual dilutions and successive testings a solution of potas- 
sium chloride of unknown strength could be brought to the 
point of containing as much potassium to the coil-full (and so, 
of course, to the cubic centimeter or any other chosen volume) 
as a standard solution of known strength. By noting the final 


* Gooch and Hart; this Journal, xlii, p. 448. 


of Rubidium by the Spectroscope. 393 


volume to which such an unknown solution was brought in 
the process of equalizing its spectrum with that of the stan- 
dard its total contents in potassium was determined. In this 
manner the strength of solutions of pure potassium chloride 
proved determinable with accuracy, but when the effect of 
intermixing pure sodium chloride with the potassium salt was 
studied it transpired that the brilliance of the potassium spec- 
trum was markedly increased by the presence of the sodium 
in the flame, the maximum increase, which amounted to 
twenty per cent, appearing when the ratio of sodium chloride 
to potassium reached 100: 1. It was found, however, that the 
practical difficulty of determining potassium in presence of 
sodium could be largely overcome by taking the precaution to 
bring the test solution and the standard to apparent equality 
as regards the potassium line, then to bring the solutions to an 
equality i in respect to the sodium line by “addition of sodium 
chloride to the standard, and finally to readjust the volumes of 
test and standard until the potassium lines were again equal. 
The accuracy of the determination of the potassium is, how- 
ever, in spite of the precaution, somewhat affected by the 
presence of sodium,—the error, though, sometimes falling as 
low as > mg. in 10 mg., rising occasionally to 1 mg. in 15 mg. 
With the excellent gravimetric method which we possess for 
the determination of potassium recourse would, naturally, 
never be taken to the spectroscopic method except in cases 
when the determination of small absolute amounts are con- 
cerned, but in such cases the spectroscopic method may prove 
a convenience. 

In the work upon potassium the observations of the red line 
were made in the ordinary laboratory in diffused light, but 
preliminary experimentation upon the rubidium spectrum 
immediately developed the fact that the blue lines are better 
to work by in the ease of this element, and that a dark room 
becomes a necessity. For the experiments to be described 
pure rubidium chloride was prepared by many fractional pre- 
cipitations by aleohol out of aqueous solutions, and in settling 
the question as to the coils which should be ‘used the choice 
fell upon the size holding 0:02 grm. of water and made of the 
No. 28 wire, the superior stiffness of these and consequent 
constancy in capacity giving them the advantage over smaller 
coils of finer wire, though the latter are capable of bringing 
out greater sensitiveness of the reaction. We found, for 
example, that under the most favorable conditions as to height 
of flame and width of slit, 0-0002 mg. of rubidium chloride 
produced the blue lines at the last limit of visibility when the 
larger and heavier coil was in the flame; with a coil holding 
0-006 grm. of water and made of very fine wire the more 


394 Gooch and Phinney—Quantitative Determination 


immediate volatilization of the chloride so increased the deli- 
cacy of the spectroscopic reaction that it was possible to see 
the lines from 0:00005 mg. of the salt. These figures serve as 
an indication of the possible delicacy of this method of pro- 
ducing spectra, but it should be remembered that all ore do 
not see the rubidium lines with equal ease. 

In experimenting with rubidium sulphate in place 68 the 
chloride the lighter coil appeared to lose its advantage in point 
of delicacy of the indication over the larger coil, possibly be- 
cause the amount of metal introduced into the flame has less 
influence upon the rate of vaporization of the less volatile sul- 
phate, and the lines of the sulphate appeared equally distinct 
and of longer duration than those of the chloride; but, while 
we judged the sulphate to be rather preferable in qualitative 
work, our earlier preliminary quantitative experiments led us 
to abandon it for the purposes of our investigation on account 
of the great uniformity in the lines yielded by the chloride. 
We found it desirable in comparative tests of brightness to 
employ as the standard the lines given by amounts of the 
chloride not exceeding 0:0005 mg. to 0:0007 mg., to set the 
slit at a width of 0-2™™, and to bring the coils to the flame in 
sets of three-—the first, usually a standard, ser ving to fix the 
position of the lines so that the comparative distinctness of the 
lines given by the other two might be the more readily deter- 
mined. The tables below contain the record of an attempt 
to dilute a solution of the pure chloride to the strength of the 
standard solution under the guidance of comparative tests of 
the brilliance of the spectral ‘lines yielded by the residue left 
upon the wires after the evaporation of the solutions taken up 
by coils of equivalent capacity. Dilutions were made in ordi- 
nary graduated cylinders of suitable capacity. 


EXPERIMENT I, 


Standard. — Test (known to Line of test 
Rubidium in contain 10 mg. Rh.). compared 
a coil-full (345 em®). Volume in em’. with standard. 
0:0005 mg. 200 Brighter. 
ce ti 300 Brighter. 
es i 350 Brighter. 
rf 370 Brighter. 
Y 390 Brighter. 
se 400 Brighter (faintly). 
ct : 400 > Brighter (faintly). 
ie <6 400 \ Doubtful. 
if oc 410 \ Brighter (faintly). 
oe t 410 | Weaker. 
s 420 } Equally bright. 
af 6 420 { 1 Weaker. 
ee ee 430 Invisible. 


of Rubidium by the Spectroscope. 395 


When the volume of the test-solution reaches 400 em* the 
indications are, on the whole, that the solution is still stronger 
than an equal volume of the standard ; and when the volume 
amounts to 420 em* it is safe to conclude from the indications 
that the test-solution is the weaker. If the mean of the num- 
bers representing these two volumes be taken as probably indi- 
cative of the volume at which the test and standard lines are at 
an equality we have the estimated amount of rubidium in the 
test-solution given by multiplying the volume in cubie centi- 
meters by the number of coil-fulls in 1 em* and the product 
by the amount of rubidium contained in a coil full of the 
standard solution—410 X50 x 0:0005=10'25 mg. The amount 
of rubidium actually taken in the test-solution was 10 mg., and 
the error of the mean value assumed is 25 per cent+, 
between extremes corresponding to an error of 0 and 5 per - 
cent +, respectively. 


EXPERIMENT II, 


Standard. Test (known to Line of test 
Rubidium in contain 10 mg. RD.), compared with 
a coil-full (345 cm?.) Volume in cm?. standard. 
0°0005 meg. 340 Brighter. 
ge ee 370 Equally bright. 
a 4 370 Brighter. 
Ts ee 390 Weaker. 
cc co 390 Weaker. 
Found eile mart! - 39° 50<0-0005 ==) (5) jay 
ARG ay a ize) Sat DSi 8 tei te oi LOO 2 
IEisT Opera et weer eres ate valam MLUILAMR Ea (Ne by Cd Sey per cent. 


EXPERIMENT III. 


Standard. Test (known to Line of test 
Rubidium in contain 10 mg. Rb.). compared with 
a coil-full (345 em?). Volume in cm?. standard. 
0:0005 mg. 300 Brighter. 
< cS 360 Equally bright. 
% s 380 Brighter. 
& es 380 Brighter. 
oh e 390 Brighter. 
ss «fF 400 Weaker. 
SS cs 410 Weaker. 
Found 390 ar 400 500-0005 1987/5 


IEG CSU Bie gi ah AE ae pee 10° 
poems sees Seige eet es 0°125 = 1°25 per cent. 


896 Gooch and Phinney—Quantitative Determination 


These results make it plain that when the comparison is 
made between solutions of pure rubidium chloride the spece- 
troscopie method is capable of yielding fair approximations to 
truth. In the practical determination of rubidium, however, 
the question of the effect of the presence of sodium ‘and potas: 
sium which naturally accompany it is of importance. .Atten- 
tion was therefore turned next to the consideration of this 
point, and the record of observations as to the influence of 
sodium upon the brightness of the rubidium spectrum is con- 
tained in the accompanying tabular statement. 


Standard. Test solution. Comparison of Comparison of 
Rubidium inacoil- Sodium ina lines of test by lines of test with 
full (s5 cm’). coil-full. pairs. standard, 
0700026 me. Slightly brighter. } ‘ : 
D000Ce mE. 1 0-00260 Slightly fainter, ( Brighter. 
0:001380 * . ‘ 
st 0-00260. « t Equally bright. Brighter. 
{ 0:00260 “ oes . : 
s ct 1 000520. * Equally bright. Brighter. 
0-00260 “ Brighter. 
ce 66 + > 
| 000660 « Fainter. Sug Nie 
. Q 66 +1 . 
ee ee 
o 0:00260 << Brighter. Brigbter. 
OFOMHOON < Invisible on account 
of glare. Invisible. 


It appears that within limits the presence of sodium in the 
flame increases the brilliance of the rubidium spectrum. The 
brightness of the lines is raised under the conditions to a maxi- 
mum by the presence of sodium to forty per cent of the 
weight of the rubidium, and increase in the amount of sodium 
does not further influence the brightness of the lines until the 
proportion of sodium to rubidium is as ten to one; or, speak- 
ing broadly, the difference between the dissociating effect of 
sodium upon the rubidium chloride (to which we attribute the 
effect noted) does not appear to be materially different whether 
one or a score of molecules of sodium chloride are present to 
one of the rubidium chloride. But when the proportion .of 
sodium to rubidium much exceeds ten to one the glare of light 
diffused through the entire spectrum (though the sodium line 
itself may be onl off) begins to affect the vision, and as the 
Increase advances ultimately extinguishes the rubidium lines 
utterly. The degree of increase in brilliance when the lines 
are at a maximum was determined by diluting the test-solu- 
tion until a coil-full gave a line equally brilliant with that of 
the standard. 


of eubsdium by the Spectroscope. 397 


Test solution. 
Rubidium in a 
coil-full with +8; 
of its weight of 


Standard. 
Rubidium in a 


Line of test 
compared with 


coil-full (34; em®). sodium, standard. 
0°00066 mg. 0:00066 meg. Brighter. 

ef a 0:00048 “ Brighter. 

$6 e 0:00046 “ Brighter. 

ee os 000044 “ Equally bright. 


Tt is plain that at the maximum degree of brilliance the 
sodium is responsible for. an increase of fifty per cent in the 
brightness of the lines. 

The details of similar experiments in which potassium 
chloride was introduced into the flame with the pure rubidium 
chloride are given in the accompanying tabular statement. 


Standard. 
Rubidium ina 


coil-full Go em’), 


fii { 0°00020 mg. Slightly fainter. i : 
| Gob ee mag: | 0:00040 Slightly brighter. Brighter. 
Oo ae SS OROOOZO. Fainter. | BARRA 
j | oe « Brighter. § Brighten: 
| « « Bee He Equally bright. Brighter. 
0:00040 “ Brighter. . 
66 Ce . . 
[ 0-00340 “ Fainter. Beer 
. 66 
[ 0:00066 mg Mane é Equally bright. Brighter. 
000066 ‘ Brighter. ; 
Bete. 000246 Fainter. Bre ntr 
te Pon NOLO 0066) 2° Brighter. 6 4 
| | 0-00660 “ Fainter. Bushier. 
| i a 000066 <“ Brighter. ie ‘ 
O:013 201%; Fainter. inlagniien, 
Wo es erin orooues. ¢ Brighter. Brighter. 
) 0:02000 Fainter. Equally bright. 
yy a nore s Brighter. Brighter. 
0°02660 “ Fainter. Equally bright. 
te we SW OMOORE Brighter. Brighter. 
| 0703240 Fainter. Equally bright. 
| ee 4 TF OUOGE 0 Brighter. Brighter. 
| 1 0°03340 “ Invisible. Invisible. 


Test solution. 
Potassium in 


a coil-full. 


Comparison of 
lines of test 
taken by pairs. 


Comparison of 
lines of test 
with standard. 


From these results it appears that the presence of potassium 
produces an effect upon the rubidium lines similar to that of 
sodium; and, furthermore, the addition of 00004 mg. of 
potassium in the form of chloride to 0:00066 mg. of rubidium 
also in the form of chloride brings out the maximum bright- 
ness which is not materially changed by further addition of 


398 Gooch and Phinney— Quantitative Determination 


potassium up to about 0°0018 mg., but that the increase of the 
potassium to 0:0034 mg. results in diminution of brightness. 
In other words, it seems that a single molecule of potassium 
chloride has approximately the same dissociating effect upon 
the molecule of rubidium chloride in the flame as that brought 
about by a greater number, that the presence of potassium in 
the proportion of five parts to one of the rubidium begins to 
influence visibility unfavorably, that when this proportion 
rises to thirty to one of the elements (or twenty to one of the 
chlorides) the lines appear about as distinctly as if no potas- 
sium were present, and that an increase of proportion to fifty 
to one may bring about a sufficient glare of light to reduce the 
rubidium lines to invisibility. The degree of increase in bril- 
liance due to the action of potassium when that element is 
present in proportions suitable to induce the maximum effect 
is shown in the following record. 


Test solution. 


Standard. Rubidium in a coil-full Line of test 
Rubidium in a with its own weight compared with 
coil-full (345 em). of potassium. standard. 
0°00066 me. 0°00066 mg. Brighter. 
ee 6 0:00064 <“ Brighter. 
ub a6 0:00057 <“ Brighter. 
é GS 0700049 “ Brighter. 
es ce 0:00044 “ Equally bright. 
cs ee 0:00040 “ Fainter. 


It appears that the presence of 000044 mg. of potassium is 
capable of increasing the brilliance of the lines yielded by 
000044 mg. of rubidium to an equality with the lmes given 
by 0:00066 mg. of the pure salt; or, that the maximum 
increase of brightness amounts to fifty per cent. 

It is evident, therefore, that means must be found to effect 
the separation of the rubidium from sodium and potassium, or 
of bringing test and standard to the same condition as regards 
the presence of these elements, before any reasonable degree 
of accuracy can be expected in the spectroscopic determination ~ 
of rubidium as it ordinarily occurs in nature. The separation 
from sodium is easily accomplished by the conversion of the 
salts to the form of chloroplatinates; but for the quantitative 
separation of rubidium from potassium there is no good 
method known. The question as to the practical value of the 
spectroscopic reaction of rubidium for purposes of approxt- 
mative quantitative analysis resolves itself into the problem as 
to whether by matching potassium lines as well as the ru- 
bidium lines (following the method outlined in the determina- 
tion of potassium in presence of sodium), and so bringing the 
lines of test and standard equally under the influence of potas- 


Determination of Rubidium by the Spectroscope. 399 


sium, it is possible to make the comparison between the 
rubidium lines trustworthy. It was shown in the former 
paper that in matching solutions of potassium by means of the 
red line there is no difficulty; but the convenience of being 
able to use the spectroscope without readjustment throughout 
the entire experiment made it desirable to see whether the 
blue line of potassium might not serve sufficiently well in the 
comparison. It is hardly necessary to reproduce here in detail 
the evidence bearing upon this point, but we found as the 
result that the potassium may be determined by the use of the 
blue line with an error amounting to 10 per cent or 20 per 
cent, which, though far greater than that inherent in the use 
of the red line, admits of the attainment of determinations 
which should be accurate enough for the present purpose. 
We proceeded, therefore, to make a determination of rubidium 
in presence of potassium by the process referred to, the details 
of which are given in Experiment IV. 


EXPERIMENT IV. 


0°0005 mg. Rubidium 


Standard solution containing } 0:0015 * Potassium 


to the 


coil-full. 
Test solution contained 8 mg. rubidium and no potassium. 


Step 1. Step 2. Step 3. Step 4. Step 5. 


Preliminary | | 
Preliminary test matching of K) Rematching of Readjustment Final match- 
for Rb. line. Rb line. of K line. jing of Rbline. 
Test at 20cm?) Test at 20 cm*® Test at 35 cm? Test at 35 em? |Test at 35 cm? 
gave Rb line gave K line like gave Rb lines (gave K line like'gave Rb line 
like standard. standard when like standard. standard whenllike standard. 


1 mg. of K had 2mg. were 
been added. | | present. 
Rubidium found 35 X50 0:0005 = 0°875 mg 
S Gee Tare yee terrae g hc OOM area 
EON ee ee ie ee tee so 2 O00 0G a == 9-4 per cent. 


It is evident that the percentage error is considerable, but 
inasmuch as the application of the process would naturally be 
to the determination of small absolute amounts of rubidium 
we thought it desirable to go a step further to see whether 
means are at hand for separating large amounts of potassium 
from small amounts of rubidium with an approach sufficiently 
near to completeness to bring the potassium present within 
the limits allowed by the spectroscopic method. After some 
experimentation we fixed upon the simplest possible procedure, 
viz: the solution of the salts in the least possible amount of 
water, precipitation of the mass of potassium chloride by addi- 
tion of alcohol, filtration, and the evaporation of the filtrate. 


Am. Jour. Scl.—THIRD SERIES, VOL. XLIV, No. 263.—NOVEMBER, 1892. 
27 


400 H. L. Preston— Notes on the Kansas Meteorite. 


In Experiments V, VI, VII, this mode of working was put to 
the proof. The amounts of rubidium indicated were dissolved 
in the form of the chloride in water, 0:1 grm. of potassium 
chloride was added, and the solution was evaporated and 
treated as described. 


Rubidium taken Potassium taken 


in the form of in the form of Rubidium Absolute Percentage 
chloride. chloride. found. error. error. 

We 1 mg. 0-1 grm. 08mg. 02mg. 20 per cent. 

Wale ayes Oley: Larp ie DES 33 15 per cent. 

Vaal ees Onllercs 09% oie 10 per cent. 


The error of the process is manifestly large, and only 
roughly approximate results can be hoped for when large 
amounts of rubidium are dealt with; but, if the question is 
the estimation of only a few milligrams of rubidium, it will 
appear, we think, in view of the fact that the only alternative 
is an indirect process, that even this great error is not abso- 
lutely prohibitive of what may be called fair determinations. 


XLIX.—WNotes on the Farmington, Washington County, Kan- 
sas, Meteorite; by H. L. PREston. 


Proressor Henry A. Warp has just cut several slices 
from his 1364-pound Farmington meteorite, which have un- 
veiled some interesting facts. 

In appearance the slices resemble a section of a dark gray 
conglomerate (in color much like some trap rocks) with numer- 
ous small patches or grains of iron scattered through it, the 
largest of which is 11x6™™ in its greatest diameters. 

In the corner of three of these slices there are several veins 
or fissures extending from 10 to 75™™ from the edge of the 
slice toward the center; and some of these fissures or fractures 
are filled with iron for 65™" in length from the edge of the 
slice inward, while in width they are but one millimeter or less. 

On the opposite end of the slice there is a very narrow 
vein, about 90™ long, which for the greater part of the 
way is filled with iron. Beyond the larger grain or nodule 
spoken of and these veins, the balance of the iron is scattered 
rather evenly throughout the mass in comparatively small 
rains. . 

: For the origin of these fissures and their partial filling up 
with iron, as seen in the accompanying cut, I would suggest 
the following explanation : 


HI. Wood—Cretaceous of ‘Northwestern Montana. 401 


That, as the meteor struck our atmosphere, the concussion 
was so great that the mass was fractured in various places, of 
course extending from the surface inward, and the larger of 
these fissures or fractures were then filled by the metallic iron 
which was fused on the exterior surface of the mass, due to its 
velocity through the atmosphere, and was thus foreed in a 
molten state into its present Boston thus forming the metallic 
veins. 


Diagrammatic sketch of slice of Farmington meteorite, showing metallic veins. 
(+ natural size.) 


I have attempted to obtain the Widmanstiitten figures on 
the largest nodule of iron in the mass, but thus far have been 
unsuccessful. 


ART. LAA Note on the Cretaceous of Northwestern Mon- 
tana; by HERBERT Woop. 


THE geographical position of the Flathead Coal Basin is 
indicated by the accompanying map, it being a continuation 
southward of the Flathead Valley, south of the North Koo- 
tanie Pass, the Elk River and Crows’ Nest Basins* in Southern 
British Columbia or more particularly Alberta Province. It 
is the inter-mountain Cretaceous which forms the connecting 
link between the Cretaceous of British Columbia and Tobacco 
Plains to the northwest and the Sand Coulee, Bozeman and 
Rocky Fork Cretaceoust east of the main range or Rockies 


* Dawson, G. M.: Report (map) 1886, Can. Geol. Sur. 
+ W. H. Weed: Engineering and Mining Journal, May, June, ’92. 


402 H. Wood—Cretaceous of Northwestern Montana. 


proper in Montana. Exposures of this inter-mountain series 
are found as far south as the 48th parallel along the banks of 
the south fork of the Flathead River, also in the vicinity of 
Marias Pass through the Rockies. Still farther south, a hun- 
dred miles or more from the 49th parallel, a younger series of 


Ite 


( Sa 
pS the alse 
(OR? “ag > nent 

ie or a 


serercane represent the limit of Gravel Deposits. 
— represent the Coal Exposures examined. 


the Cretaceous has been observed in the vicinity of Missoula 
extending 18 miles east and west and dipping into the moun- 
tains at 30° northwest. It consists of clays, shales and 
sandstones, with small seams of impure lignite, and capped 
with a heavy conglomerate, the series resting unconformably 
on the greatly denuded upturned beds of the Cambrian or 
Pre-Cambrian rocks which dip south 25°. The valley is a 
plateau valley from fifteen to twenty-five miles in width and 
thirty to forty in length, with heavy beds of bowlder and 
gravel detritus, the grooved and polished rocks (gray quartz- 
ites of the Cambrian), on the flanks of the southern range 


Hf. Wood—Cretaceous of Northwestern Montana. 403 


showing the glacial path as 40° north of west. These gravel 
deposits, consisting largely of greenish and greenish-black 
amygdaloidal traps, have a thickness of one hundred to one hun- 
dred and fifty feet on the upturned edges of the Cretaceous 
rocks, their lower portions being formed into beds of calca- 
reously cemented sandstones and conglomerates. The origin 
of the amygdaloidal trap bowlders is no doubt: in the interca- 
lated eruptive rocks of the Cambrian and Cretaceous at the 
north and south Kootanie passes.* All the valleys of this 
portion of Montana have a southerly or southeasterly direction 
exhibiting evidences of glaciation as bowlder clays, lakes 
behind terminal moraines, and rounded hummocky remnants 
of ranges, in some cases extending for 150 miles from the 
boundary or those higher altitudes which existed during or at 
the close of a supposed epirogenic movement.t The range 
flanking the valley on the south has a course a little northwest 
with numerous transverse valleys, and corresponds with the 
lower Cambrian Quartzitic series or Bow River series, as noted 
by McConnell.t It dips east-northeast under the upturned 
coal-bearing Cretaceous rocks. ‘The Cambrian here consists of 
heavily bedded red quartzites changing to sandstones alter- 
nating with thinly bedded dark red argillaceous shales, and 
lower in the series with greenish quartzites of ribbanded char- 
acter, the upper portion of the series immediately underlying 
the Cretaceous consisting of greenish gray quartzose slates. 
The total thickness of this lower Cambrian, 1. e., all that below 
the dolomitic limestone and shales, as given by Dawson§ is 
11,000 feet; by MceConnell| and Walvott 10,000 feet—the 
latter of whom’ has recorded his results from the Gallatin sec- 
tion, eastern Montana. A rough traverse made here along 
Coal Creek gave me 2% miles of upturned Cambrian rocks. 
The total thickness of the series as given by Dawson is 29,000 
feet. 

A search was made for fossils but none were obtained, nor 
does it appear that any were found in this series in southern 
British Columbia. The dip of the red quartzites is 25° E.N.E., 
while the dip of the gray quartzose slates immediately under 
the Cretaceous is 35° to 40° E.N.E., with a strike 20° north of 
west. Evidences of shore lines were observed in the shape of 
ripple marks, but no conglomerates or intercalated contempo- 
raneous trappean rocks. The direction of this range is nearly 


*G.M. Dawson: Report 1886, pp. 46, 47, 57. 

+ Upham: Class. of Mount. Ranges. 

t McConnell: Rep. 1887, C. G.S., p. 29. 

§ Dawsou: Rep. 1886, 0. Gans v. oil 

|| McConnell: Rep. 1887, CHGe a p. 29. 

“| Walcott: Correlation papers Camb. G. Survey. U.S 


404 LH. Wood—Cretaceous of Northwestern Montana. 


east and west while the range west of the Flathead at the 
boundary has a northwesterly trend, the rocks as noted by 
Dawson, ‘greenish close-grained quartzites* and red sand- 
stones” being altogether likely the same geological horizon as 
those farther south.t He notes, however, farther west ‘a 
hard greenish amygdaloidal diorite.” If such intercalations 
are present south of here they escaped my notice. 

The Cretaceous beds rest with their upturned edges against 
the greenish gray quartzose slates of the Cambrian. It consti- 
tutes a series of clays, clay shales, coarse and fine-grained 
sandstones of about 7,500 feet in thickness{ corresponding 
with that of the North Kootanie series. At the base of the 
Cambrian range the dip of the Cretaceous is 50° KE N.E. and 
1? miles north across the strike the dip is 8° and 10° 
E.N.E., this section at Coal Creek showing the greatly 


2. 


SECTION AT COAL CREEK. 


1. Cambrian. 4. Gravel Deposits. 
2, Cretaceous. 5. Flathead River. 
3. Camb. Dey. Sub-Carb. (Rockies). 


denuded southern margin of a synclinal fold. The basal por- 
tion of 1,000 feet of the series is coal-productive, exhibiting 15 
or 20 seams of lignite. The upper portion of the series con- 
sists of heavily bedded sandstones with shaley partings with 
some small seams of impure lignite. A phenomenal local 
thickening$ of the coal seams was observed two miles south- 


* Dawson: Rep. 1886, p. 55. 

+ One hundred miles directly south of this in the vicinity of Missoula, a few 
fossils were obtained in the siliceous limestone (dolomite) identified by Mr. Chas. 
Schuchert as Obolella. One or two fossils were found in the red semi-argilla- 
ceous slates also but are not yet identified. 

¢ This is the result of a tape line measurement and foot traverse made at Coal 
Creek. 


SCoal gene eis Meese wee Srboxolavesss,: OOF ete ue 22 inches. 
Clayaishale arene easement Ginnie: Free Sandstone_.___._---- sien s 
Coal rao Cota Nueti a eyea Bie Calls Fe ees UR SE seen a 
ClayAshalemn aia eee Gas Clayiishalle imme Balun Uke i 
Coals Res iar | ae AN ye Coa) EO ARUN EER CORRS CR Ais 
Sanidiyscl aryse mie eck nee OB 8 Clery ih) aa ee aim Re ee a 

CO Kopet Saasak es ee GH ss Oc ta ine 8 (CG BN es aes ps ea 134 feet. 
OV ayy eek 2S SA Sa ae Sua Clary iS Va eee 21 inches. 
(roe ete eceanincnay snr alon 3 Lia Tee Callies SSH TE uae Se Ale}. | 
Clay ites ICIe IS a OD Bh 08 


Three additional seams of coal outside the tunnel aggregated 12 feet. 


H. Wood—Cretaceous of Northwestern Montana. 405 


east of Coal Creek canyon at the Emerson Tunnel, thirteen 
seams being exposed in 150 feet. One seam measured 184 
feet and the combined thickness of the different coal seams 
equalled 42 feet. 

No fossils* were observed in the series nor intercalated 
traps, ash beds or agglomerates, as noted by Dawson.t 

Ten miles northwest of Coal Creek and four miles north of 
the Cambrian range, a heavy conglomerate of red and green 
quartzite pebbles (presumably of Cambrian origin) was found. 
These heavy conglomerates are described by Dawson as occur- 
ring at Crow’s Nest, Kootanie Passes, and other places—the 
voleanic horizon occurring apparently above this. My detour 
did not extend to the boundar y, but eight or ten miles south of it. 
It is not improbable that the upper portions of the series might 
be found near the line. My observations extended over four- 
teen miles along the strike of the rocks, and 1 found that the 
margin of the fold swings from 12° S. of west at the Emer- 
son Tunnel, through all intermediate variations to 25° north of 
west, this latter observation being taken 14 miles northwest of 
the first. This last strike was taken four miles north of the 
Cambrian, and suggested the assumption of some intervening 
formations between this and the Cambrian, possibly Devonian.t 
A large number of dips taken throughout the series, gave a 
gradual variation from 51° H.N.E. to 8° E.N.E. Across the 
strike of two railes or a little less, a rapid change in dip was 
noted at the Emerson Tunnel, two miles southeast of Coal 
Creek. The tunnel is 102 feet in Jength and gave a variation 
from back to front of ten degrees—51° to 41° northeast. The 
presence of the conglomer ate, the absence of any evidences of 
volcanic action, as well as fossils, the relative position in the 
series of the clays, shales, and sandstones, with a basal coal 
productive series, as well as the thickness of the whole, seems 
to correlate these beds with Dawson’s series observed at North 
Kootanie,§ making this region identical with the Crow’s Nest 
valley. The latter beds, however, seem to display a greater 
variety of fossiliferous forms. 

It may be said here that the Bozeman, Cinnabar and Rocky 
Fork Fields| are of Laramie age, while the Sand Coulee is 
lower in the geological horizon. 

The coal is a lignite, exhibiting no changed condition result- 
ing from crushing or violent metamorphic action as shown by 


* One fossil plant form was found in a heavily bedded series of sandy clays 30 
feet in thickness, 10 miles west of Coal Creek. 

+ Dawson: Report 1886, pp. 57, 59. 

¢ The Report of ’86, Can. Geol. Survey, shows the Devonian as crossing the 
boundary on the west side of the Flathead River. 

§ Dawson: Report 1886, pp. 64, 69. 

|| Weed: Engineering and Mining Journal. 


406 R. 1. Hill—Deep Artesian Boring in Texas. 


the Elk River,* Crows’ Nest,+ Cascade coal, these being semi- 
bituminous and anthracitic in character. In these latter in- 
stances the flexure is more complex and shows. evidences of 
great crushing and metamorphic action. The coal of Sand 
Coulee and Bozeman and Rocky Fork,t is also bituminous in 
character—the latter region having been subjected to volcanic 
action, intercalated beds and dikes of eruptive rocks being a 
feature, which indeed characterizes many sections of the Cre- 
taceous in the west. The Cretaceous here has not been thus 
disturbed, the coal being purely lignitic throughout, contain- 
ing nodules or lumps of mineral resin, presumably succinite 
or an allied mineral. The series has been subject to lateral 
squeezing, folding and upheaval which turned the beds up 
against the Cambrian on the sonth, and against the Rockies, 
the Cambrian, Devonian and Sub-Carboniferous on the north. 

No examination was made along the north side of the valley 
for Cretaceous, but the evidence all affirms the supposition of 
a simple synclinal fold,§ much the same as exhibited at the 
North Kootanie Pass—the upheaval following at the close of 
the Cretaceous period. The Cambrian has been subjected at 
least to two periods of upheaval, if not more, the first being 
Paleozoic and the last as above mentioned. This is shown in 
the position of the Cretaceous, one hundred miles south of 
this resting unconformably on the greatly eroded, upturned 
edges of the Cambrian, where, however, the Cretaceous has 
not been subjected to any flexure or folding, but to a slow 
upheaval or movement of the crust which must have been 
pretty general in its character. 


Art. LI.—TZhe Deep Artesian Boring at Galveston, Texas ; 
’ by Rosperr T. HI. 


AN experimental well has recently been drilled for the city 
of Galveston, Texas, to the depth of nearly three thousand 
feet, the results of which are of great value to geologists 
interested in the sedimentation of the Gulf of Mexico. 

Galveston is situated on one of the island sand bars that 
mark the western border of the Gulf and nearly the entire 
depth of the drill hole is below sea level. Hence the accom- 


* Dawson: Rep. 1886, p. 69. 

+ Ibid.: Mineral Wealth, Br. Columbia. 

¢ W. H. Weed: Kng. and Min. Jour., May and June. 

S Some evidences have been obtained from the descriptive topography of sur- 
veyors of minor flexure. 

|| Provisionally given—may be Pre-Cambrian. 


R. 7. Hitl—Deep Artesian Boring in Texas. 407 


panying record is entirely of sediments constituting the present 
sea bottom. 

In the Engineering News of August 11, 1892, Mr. Byrnes, 
the contractor, published a valuable article on the engineering 
problems involved, together with the following section illus- 
trating the character and thickness of the sediments passed 
through up to that date. Work has since been continued on 
the well and it is no doubt at present down to three thousand 
feet : 


Grraivyasand iy eee Oh eo baeek cas EE ets a 0 ft. 
edsclayaawitheshellse: ei aes shana ee 7 is ose 46 
Red and blue clay, withishells 5222522525252 2222 63 
Same with fragments of wood .-...--------- 84 to 100 
Gray and reddish sand, with occasional logs, 84 to 100 
Rediclay andishelluotes3iis. =4-- se ee oe ae ee 338 
Sanduwith woodvand shelly t= Vso. 2 secre 400 
Sand and sandy clay to 

MOpROLe Waters SANG sacar. Se hhh ets te eras) crys or nate 827 
Wiate ri samdleie 2 iptonee ects oe ee tera eeite eee RS he 882 


Sand (principally) and clay with wood and shell _- 
882 to 1089 
Very hard rock, probably conglomerate.-.1089 to 1090 


Dan dyaclayaandusand (Ones os mek Sameer e men 260 
Wiatersand 1260) to\5 52s s Daa bee Se cee 1228 
Sandy clay, varying hardness 

Sandstone 

Widtersamd: 149039 tomer Se cet els eer ae bea 1510 
Clay with shell, pebbleand lime>_ 2-22.22 0.5222. 1520 
Sand with same clay strata to 
Calcareous sandstone probably .---------- 1754 to 1758 
WAMGE Cone ae eres Sas ea Peres RL 1862 
Claya(principallix and! sanditose=s2 5 sae sess 2153 
Clay with shell and wood fragments- - - --- 2153 to 2196 
Same. Also sand and joint clay to 

Concretionary limestone, probably -------- 2288 to 2291.5 
Sand and joint clay with shell and wood_.---.--- 2349 
WWeatensan (SAM (st Opmeryets 5 0h te ys arouse 2349 
Claygand: fine: sandgeey ss. 5-5 ee ie Oh ee et 2397 
ve Grandi er Claygate 1 cee arn eet DADS 
WWiaterisand.) 52 ces ieee hin rua 2425 to 2443 
redvand blue\ clay andi lionite.. 92 9-5. 22.8 522! 2443 
Red and blue clay with alternating sand strata... 2504 
Whatersandeandubluetelayes. 22 a eo 2504 to 2567 
indiaratedvoray sand tonee= 2405 Goes eae 2598 
Blue and red clay, some gravel to 

Weryptineveray sandyat, e200) 2.0) toi tek 2631 to 2637 
vedrandublucrclayyecee soe s one eae .. 2653 


Palenviellowac layer Alas soe 9573) 2 teal em seamen ae 2698 


408 LR. T. Hill—Deep Artesian Boring in Texas. 


Blue and yellow clay, and gray sand ..-.-------- 27738 
Very soft blue clay and reddish clay~----- 2733 to 2871 
WOarseiSartdl ei). 28 Ease Bye ee ea eae 2871 to 2863 
The drill was in soft clay and fine sand at ___.__- 2863 


No paleontologic data having been given I can only inter- 
pret these through my knowledge of the outcrop of the strata 
on the adjacent coastal plain bordering the Gulf east of Austin 
and San Antonio. It is said that Mr. Singley, a local observer, 
has carefully collected the paleontologic data, which it is hoped, 
he will publish. 

In studying the section one is impressed by the littoral 
character of its material and the absence of indurated or con- 
solidated rock, and the chalky marls and limestones charac- 
teristic of the Upper Cretaceous formation, leaving the 
impression that the 2863 feet of sediments are almost if not 
entirely composed of post Cretaceous beds. 

Every foot of the deposits passed through in the well can 
be seen in the adjacent outcrops of Texas to-day. These 
belong to three formations. The provisional interpretations I 
would place npon the well are as follows: 


No. Strata in well. Formation. Age. 

ile O80 Coast Prairie Beds. Pleistocene. 

2 827-1754 Fayette Sands of ‘Phocene Miocene. 
Penrose. 

3° 1754—=2653 Lignitic Eocene. Eocene. 

Bees Wh Ap Eee Ea Se So eee ahr ie OR ee SDE ay eh 


5 2653-2863 Probably Eocene but may be Upper Cretaceous. 


These formations have been described by Penrose, McGee 
and the writer. No.1, the Coast Prairie beds are supposed 
by McGee to represent the southern stage of the former 
Columbian formation, and were laid down at marine base-level 
continuing around the coast into Louisiana, No. 3, is the well 
known Eo-Lignitic formation of the southern United States, 
as described originally by Hilgard as the Great Northern Lig- 
nite.* Penroset has shown the general character of the 
formation in Texas and the writert in Arkansas. It is un- 
doubtedly the direct geographic continuation in part of the 
Laramie beds of the Rocky Mountain region, as shown by Dr. 
C. A. White§ and the writer.| No. 2—the Fayette Sands— 
is a more problematical formation. Its general occurrence has 

* Agriculture and Geology of Mississippi, Jackson, 1860. 

+ Preliminary Report on the Geology of the Gulf Tertiary of Texas, from Red 
River to the Rio Grande. Austin. 

+t The Neozoic Geology of Southwestern Arkansas, Little Rock, 1887. 


§ This Journal. : 
|| Notes on the Texas New Mexican Region, Bull. Geol. Soc.. vol. iii, 1891. 


Rk. T. Hill—Deep Artesian Boring in Texas. 409 


been pointed out by Penrose, but no satisfactory interpreta- 
tion has been made of its limitations and history. As shown 
by Shumard* and Copet it contains the wonderful mam 
malian vertebrate fauna of the Loup Fork and Equus beds 
which are supposed to be of Miocene and Pliocene age. Its 
sediments are identical in many unique characters with those 
of the formations I have seen in Nebraska and on the Staked 
Plains containing besides the same vertebrate remains the 
peculiar opalized wood and quartz grains imbedded in a lime 
matrix identical with the mortar beds of Kansas described by 
Hay. It is evidently the coastward extension of the Great 
Plains formation which, as I have shown, extends over the 
whole Llano Estacado to the Rio Grandet as far as Spofford 
Junction. Whether this formation was deposited at marine 
base-level or was laid down upon the land after the manner of 
deposition now going on so extensively over the arid region of 
Mexico is an interesting problem. One fact is positive, how- 
ever, and that is that it represents a period of great aridity 
which prevailed in Miocene and Pliocene time throughout the 
region of its occurrence. 

These three sheets of sedimentation, representing 827 feet 
of Pleistocene beds, 927 feet of later Tertiary—Miocene and 
Pliocene—and 2000 feet of Hocene'deposits reveal a great 
load upon the coastal plain, and each, according to the doc- 
trine of isostasy, would afford a sufficient factor to account for 
the important movements of their respective epochs. 

Could the well go deeper into the 2500 feet of Upper Cre- 
taceous chalks and clays and the 2500 feet of Comanche 
deposits the total load upon the Gulf’s margin since the sea 
first began its oscillations over the Texas region in Wealden 
time would amount to 8000 feet. 

The oldest and latest of the three divisions into which I 
have divided the section, the Eocene and Columbian respec- 
tively, were deposited in very shallow water under conditions 
identical with the sedimentation of to-day, while the middle 
division no doubt represents even as shallow if not shallower 
deposits but under entirely different climatic conditions. All 
must represent subsidence, although there were no doubt 
intervening periods of elevation which can only be interpreted 
upon the land, according to the methods of the modern school 
of physical geologists. The total subsidence of the old Eocene 
shore line, according to this boring has amounted to nearly 
three thousand feet. 


* Trans. St. Louis Academy of Science, vol. ii, 1868, pp. 140-141. 

+ Various papers of Professor E. D. Cope. 

¢ Occurrence of Underground Water in the Texas New Mexican Region. 
Washington, D. C., 1892. 


410 Beecher and Clarke—Lower Oriskany 


Art. LII.— Notice of a new Lower Oriskany Fauna in 
Columbia County, New York; by C. E. BrecuEer. With 
an annotated list of fossils ; by J. M. CLARKE. 


Jt 


In 1890, while making collections and geological sections 
in the Becraft’s Mountain region of Colambia County, New 
York, a fauna was discovered by the writer, which in many 
respects is new to the State. Its affinities are with the Oris- 
kany, but its geological position is below the true Oriskany 
sandstone. It appears to include a part, at least, of what has 
been considered as the Upper Pentamerus limestone, and has 
been referred to the Lower Helderberg group on account of 
its lithological characters and upon insufficient paleontological 
grounds. The fauna of the Upper Pentamerus in its original 
locality (Schoharie, N. Y.) has previously been recognized to 
contain several species quite distinct from the Seutella, Shaly, 
and Lower Pentamerus limestones, which represent the typical 
Lower Helderberg group. Moreover, as the complete fauna 
has remained unknown and the series has been confused with 
the underlying Scutella limestone, no exact correlations have 
been made. 

From the fossils now known from Becraft’s Mountain and 
several other localities, it is evident that the relations of the 
fauna contained in the upper beds of the series above the 
Scutella limestone and just below the Oriskany sandstone are 
with the latter, and not with the Lower Helderberg group. 
This is shown by the presence in these beds of such typical 
Oriskany species as Hdriocrinus sacculus, Pholidops termi- 
nalis, Leptostrophia magnifica, LHipparionyx proximus, 
Leptocelia flabellites, Spirifer arrectus, Spirifer arenosius, 
Cyrtina rostrata, Rhynchonella oblata, and Rensseleria ovoides. 
This list has been revised by Mr. C. Schuchert, who has made 
a careful study of the Oriskany brachiopods. 

At Becraft’s Mountain the rock is a hard, cherty, arenaceous 
limestone, weathering into a rotten fine-grained sandstone, 
preserving the moulds of the fossils or their silicified replace- 
ments. On Catskill Creek, near Leeds, as shown by speci- 
mens received from Mr. W. W. Dodge, the rock contains less 
sand, and does not weather into a softer condition. At Port 
Jervis, N. Y., it isin general still more calcareous, although there 
are some cherty layers, and many of the fossils are silicified. 
Here, too, the series is continuous from the Oriskany sand- 
stone down through the trilobite beds of Mather, Horton and 
Barrett. The arenaceous character of the beds gradually 


Fauna in Columbia Co., New York. 411 


decreases downwards, carrying the typical Oriskany species 
into the Dalmanites dentatus layers and below, and making 
the whole series of this group at Port Jervis probably over 
two hundred feet in thickness, of which one hundred or more 
belong to the Lower Oriskany. ‘The relations of these beds to 
the Oriskany was appreciated by Barrett,* who was led, how- 
ever, to refer them to the Lower Helderberg on account of the 
occurrence of some doubtful Lower Helderberg species and 
their stratigraphical position. 

In the paper on Becraft’s Mountain by W. M. Davis,+ the 
Upper Pentamerus, including the Scutella limestone, is stated 
to have a thickness of from forty to fifty feet, followed directly 
by the Cauda-galli shales. At Rondout, he recognized a re- 
currence of the Shaly limestone above the Scutella beds. The 
same conditions obtain at Becraft’s Mountain, and at the top 
occur the few feet of cherty and arenaceous beds containing 
the Lower Oriskany fossils. 

The paleontological aspect of this fauna is of much interest, 
especially on account of the large number of genera and spe- 
cies new to the Oriskany group and species new to science. 
Even the forms which are characteristic of the Oriskany 
sandstone above offer slight variations in size and features 
which enable them to be recognized as from a somewhat older 
horizon. As a whole, the fauna is transitional. A few of the 
Lower Helderberg types lingered; others were changed into 
species intermediate between Lower Helderberg and true 
Oriskany and Corniferous forms; and new types also appeared, 
which in the higher rocks reached a greater development. 
Among some of the new types of structure may be mentioned 
the coarsely plicate Leptoceelia, the Spirifers with plications in 
the sinus and the Corycephalus group of Dalmanites, having 
the outer margin of the cephalon denticulate. Cc. E. B. 


de 


A preliminary List of the Species constituting the Oriskany 
Sauna of Becrafts Mt., N. Y. 


(Names in roman are of species present in the normal Oriskany or Aipparionyx 
fauna of Central New York and the Schoharie Section; for convenience of reference 
the letters H and D are placed before names of species belonging respectively to 
Lower Helderberg and upper-Lower, or Middle Devonian types.) 

FIsHES. 1. Spine of undetermined species. 

ANNELIDS. 2 Spirorbis sp. 

(D) 3. Autodelus sp n. This genus is also represented in the Hamilton shales, 
but by a much larger species. 


* Ann. Lyceum Nat. Hist. N. Y., vol. xi, p. 297, 1876. 
+ This Journal, III, vol. xxvi, pp. 381-389, Nov., 1883. 


412 Beecher and Clarke—Lower Oriskany 


Triuosites. (H) 4. Dalmanites sp.n. A. A large Odontochile with a series of 
marginal crenulations about the cephalon, of the character of those in D. plewrop- 
tyx of the Shaly limestone and JD. anchiops, of the Schoharie grit, but more 
extensive than either. The lateral glabellar lobes are more confluent than in 
the earlier (Niagara and Lower Helderberg) species. The genal angles end 
obtusely or in small spines. The pygidium is broad and unusually short, ending 
in a sharp, angular termination, but not in a spine. Annulations simple and very 
distinct; about 10 on the axis and 9 on the pleure. This is the largest and most 
abundant of the species. Some of the cephala measure 34 inches in diameter. 

(H) 5. Dalmanites sp.n. A. var. This is represented by a series of pygidia 
similar in annulation to the foregoing but persistently different in much smaller 
size, more slender form and tapering outline. It is closely similar to D. micrurus, 
of the Lower Helderberg, but less abundantly annulated. 

6. Dalmanites sp. n. B. Long, slender pygidia with acute but not extended 
terminal spine. Annulations of axis about 15; of pleure, 12. On the axisisa 
double median row of conspicuous tubercles and there are irregularly scattered 
tubercles on the pleural ribs. This may be compared in form and ornament with 
D. dentatus, of the Port Jervis series, but it is more abundantly annulated and 
without the strong caudal spine of that species. 

7. Dalmanites sp.n. C. A single pygidium, quite distinct from the rest, has a 
tapering outline, high convexity, broad, acute caudal extremity and strong simple 
annulations. There are 7-8 annulations on the axis, 8-9 on the pleura, all termi- 
nating at a considerable distance from the extremity of the shield. The expres- 
sion of this pygidium is well defined and suggests in some respects, that of a 
small, sharply annulated Homalonotus. 

(H) 8. Dalmanites sp.? D. There is evidence of another species of this genus 
with a pygidium somewhat similar to that of D. plewroptyx. 

(D) 9. Dalmanites phacoptyx, Hall. This species has heretofore been known 
only in the Upper Helderberg limestone of the Province of Ontario. 

(H, D) 10. Phacops sp. n. Heads and pygidia are not uncommon. The 
form of the glabella is somewhat appressed laterally and is suggestive of P. cepha- 
lotes Barr. The genal extremities beara single spinule or tubercle as in P. Logani, 
of the Shaly limestone, and P. pipa, of the Upper Helderberg, but the glabella 
does not show the lateral furrows distinctive of the earlier species of this genus. 
The segments of the thorax bear nodes at the axial furrows, such as characterize 
P. Logani, though the annulations of the pygidium do not appear to be duplicate 
as in the Lower and Upper Helderberg species. Some small examples do not 
have we thoracic nodes and these may represent a distinct specific form. 

(D) 1 Phacops (Acaste) cf. anceps, Clarke. This species has heretofore been 
found bai in the Upper Helderberg of the Province of Ontario. 

(D) 12. Homalonotus sp. Occasional fragments indicate a species of sani 
size, differing from the gigantic H. major, occurring in the Oriskany sandstone of 
Ulster Co. 

(H) 13. Cordania* sp.n. Allied to C. cyclurus, Hall, of the Shaly limestone 
but differing in details of ornamentation. 

(H, D) 14. yphaspis sp. nu. Of the type of C. celebs (Lower Helderberg) and 
C. minuscula (Upper Helderberg) but with proportionately much larger cephalon. 

(D) 15. Proetus sp.nu.? A. A small form of the P. angustifrons- -clarus-Rowi 
type. 

(D) 16. Proetus sp. n. B. A much larger form with highly convex glabella and 
multiannulate pygidium; of the type of P. crassimarginatus of the Upper Helder- 
berg. 

(H) 17. Acidaspis tuberculatus, Conrad. A characteristic species of the Shaly 
limestone. 

OSTRACODES. 18. Leperditia sp. 19. Primitia sp. 

CIRRIPEDES. 20. Turrilepas sp. 

(CEPHALOPODS. No representative of these fossils has been observed.) 

GAsTRopODS. 21. Platyceras tortuosum, Hall. 22. P. nodosum, Conrad. 
23. Strophostylus expansus, Conrad. 24. Diaphorostoma ventricosum, Conrad. 


*The writer has introduced this name in a paper now in press, for certain 
American species which have been referred to the genus Phaethonides, Angelin. 


Fauna in Columbia Co., New York. 413 


(D) 25. Diaphorostoma sp.n. In external ornament similar to D. lineatum of 
the Hamilton shales. 

26. Cyrtolites expansus? (D) 27. Pleurotomaria sp. un. 28. Bellerophon sp. n.? 

PrEROPODS. 29. Conularia sp.? 30. Coleolus sp.? 

(H) 31. Zentaculites ef. elongatus, Hall. A very large species differing, if at all, 
from the Lower Helderberg form, in its coarser annulations. 

32. Tentaculites sp.n. A very slender form, covered with minute, equal and 
elosely crowded annulations. 

PELECYPODS. (H) 33, Actinopteria cf. tevtilis, Hall. This shell is nearer to the 
typical lower Helderberg species than to the var. arenaria occurring in the Hip- 
parionyx-fauna. 

(H) 34. Aviculopecten of the type A. Schoharie, Hall, of the Shaly limestone, 
but covered with radial ribs in addition to the very fine concentric lines. 

35. Megambonia bellistriata, Hall 36. M. lamellosa, Hall(?) 37. Gondophora 
sp.n. (H) 38. Cypricardinia cf. lamellosa, Wall, of the Shaly limestone. 39. 
Conocardium sp. 

Bracuiopops. 40. Lingula sp. 41. Orbiculoidea sp. 

42. Crania sp.n. A large shell with fine, rapidly bifurcating surface strie. 
This is of the type of C. agaricina of the Shaly limestone, but larger and more 
finely striate. Not uncommon. 43. Craniasp.n. A smooth species. 

44, Pholidops terminalis, Hall. This, and P. arenaria both of the Oriskany, are 
probably but the exterior and the internal cast of the same species. 

45. Pholidops sp.n. A small species of the type of P. squamiformis. 

(H) 46. Orthis perelegans, Hall, of the Shaly limestone. 

(H) 47. O. cf. oblata. Hall of the Shaly limestone. A small form of this type. 
48. O.sp? A small, subcircular species. 

(H) 49. Orthothetes cf. Woolworthana, Hall, of the Shaly limestone. 

50. O. sp. n. A small, very abundant shell, in size and expression suggestive of 
O. lens, of the Choteau limestone, but more variable in form and contour. 

51. Hipparionyx proximus, Vanuxem. A single specimen of a very large and 
typical brachial valve. 

52. Leptena rhomboidalis, Wilckens. The Lower and Upper Helderberg form, 
rather than the Oriskany var. ventricosa. 

53. Stropheodonta Linckleni, Hall. (H) 54. S. cf. radiata, Vanuxem. In 
some of these shells the radial strize are sharp and strongly fasciculate, producing 
an expression similar to that of S. demissu of the Middle Devonian. 

55. S.sp.n. A. A large, strongly arcuate form with fine fasciculate striz, as in 
Rafinesquina alternatu. 

(D) 56. S. sp. n. B. <A small convex form of the type of S. alveata of the 
Schoharie grit. 

57. Leptostrophia magnifica, Hall. A small variety. 

(H) 58 ZL, cf. Becki, Hall. A perplane species with low, irregular, concentric 
rugee extending to the anterior margin. The prevailing size of the shell is much 
smaller than in the Lower Helderberg form. Very abundant. 

(D) 59. L. perplana, Conrad. Persistently more convex than the middle 
Devonian form; the difference however is no more than varietal. Everywhere 
abundant. 

(HD) 60. Strophonella cf. Headleyana, Hall, of the Shaly limestone. 

61. Vitulina? If this identification, founded on a single internal cast, be correct, 
this genus appears for the first time on this continent in its normal association 
with a lower Devonian fauna, as in South America and Africa. 

(D) 62. Chonetes sp.n. A small shell of the type of C. coronata, Conrad. 

63. Chonostrophia sp.n. Differs from C. complanta of the Oriskany in smaller 
size, greater reversed convexity and distinct fasciculation of striz. 64. Anoplia 
nucleata, Hall. 

65. Spirifer arrectus, Hall. This abundant species varies considerably in size 
and plication and frequently suggests the Lower Helderberg 8S. cyclopterus. 66. 
S. arenosus, Conrad. 67. S. pyxidatus, Hall. (H) 68. S. modestus, Hall, of the 
Shaly limestone. 69. S. cf. fimbriatus, Conrad. A sparsely ribbed, coarsely fimbria- 
ted shell. Specific relations can not be more closely determined with the 
material at hand. 


414. Beecher and Clarke—Lower Oriskany Fauna, ete. 


70. Cyrtina rostrata, Hall. 71. ©. cf. Dalmani, Hall, of the Shaly limestone 

12. Meristella sp.n. This shell has many points of similarity with MJ oblata 
of the Oriskany. It is, however, a smaller, much more strongly trihedral shell, 
with the aspect of a gigantic Jf. lenta. 173. Meristella cf. laevis of the Lower 
Helderberg. 74. Meristella sp.n? A large von-sinuate species. 

(H) 15. Trematospira multistriata, Hall, of the Shaly limestone. 

(D) 76. Celosptra sp. n. In size this shell resembles C. Camilla, of the Cornif- 
erous limestone, while it bears the external ornament of C. concava of, the Shaly 
limestone, though the plications are rather more numerous. 

(H) 77. Celospira sp. of the small size of C. concava but more regularly plicate. 

78. Lepcocoelia flabellites, Hall. (D) 79. ZL. acutiplicata, Hall, of the Cornifer- 
ous limestone. 

(H) 80. Anastrophia sp.n. <A very finely plicate species. 

81. Rensseleeria ovoides, Eaton. 82. R. Suessiana, Hall.? 83. R. ovalis, Hall? 

84. Rhynchonella oblata, Hall. 85. R. Barrandii, Hall. 86. R. ef. speciosa, 
Hall. 87. R. sp.? 

(H) 88. Eatonia medialis, Hall, of the Shaly limestone. 89. EH. peculiaris, 
Conrad. 

(D) 90. Centronella, sp. n. of the type of C. glans-fagea, but of great size. 

(H) 91. Cryptonella sp.n. Similar to an undescribed species in the Shaly 
limestone. 

Bryozoans. (D) 92. Fenestella celsipora, Hall, of the Corniferous limestone. 

J3eeaspat 

(D) 94. Hemitrypa cf. columellata, Hall, of the Corniferous limestone. 

95. Polypora sp? 96. Reptaria sp. 91. Hederelia sp. 98. Clonopora sp. 
99. Fistulipora sp. 

Corats. (H) 100. Zaphrentis cf. Remeri of the Shaly limestone. 101. Z sp.? 
102. Romingeria sp. 103. Monticulipora, a branching species. 104. Trachy- 
pora, sp. 

CrINOIDS. 105. Edriocrinus sacculus, Hall. 

Sponces. 106. Hindia sp. 


This remarkable association of species furnishes the missing 
link in the evolution of the Lower Helderberg into the typical 
Lower Devonian fauna. While the presence of so many posi- 
tive Oriskany types determines the faunal quantivalence, the 
perdurance of species and modifications of specific expressions 
characteristic of the Shaly limestone fauna, and the inception 
of upper Lower Devonian specific forms, render this combi- 
nation altogether unusual and of prime significance in the cor- 
relation of our earlier Devonian. The southwestern extension 
of the Oriskany (/Zipparionyz) fauna, as in Maryland, is com- 
plicated with the Lower Helderberg, but to a less degree than 
here; while in the representative of the same fauna in the 
Province of Ontario there is a great predominance of Upper 
Helderberg species. With the 46 species which have been 
identified in the Hipparionyx fauna of New York (see list 
published by Mr. Charles Schuchert, in Eighth Annual Report 
of the New York State Geologist, p. 50, 1889), the 106 or 
more species of the Becraft’s Mt. fauna are in striking contrast, 
and no element so strongly enforces this contrast or is so 
unique in itself as the crustaceun. The association is indu- 
bitably of early Oriskany age and is eminently the Zr2/obcte or 
Dalmanites facies of the Oriskany fauna. J. MC: 


E. E. Howell— Description of the Mt. Joy Meteorite. 415 


ART. LIII.— Description of the Mt. Joy Meteorite ; by 
Epwin HW. Howe .t. 


THE accompanying cut gives a good idea of the form of the 
third largest meteorite found in the United States, and the 
largest east of the Mississippi River. 


2, 2s 


= —= 


It was found in November, 1887, on or about the 16th of 
the month, by Jacob Snyder, about a foot below the surface 
while digging to plant an apple tree near his house, five miles 
to the southeast of Gettysburg, in the township of Mt. Joy, 
Adams Co., Penn. It was supposed by the finder and his 
friends to indicate the near presence of an iron mine, and 
considerable prospecting was done to locate it. ‘The meteorite 
was placed on some timbers in the open air where it remained 
until the summer of 1891, before it was seen by any one who 
surmised its true character. 

Professor F. W. Clarke induced Mr. Snyder to send it to 
the National Museum for inspection, but was finally unable to 
secure it, as Mr. Snyder was unwilling to part with it fora 
price, which the museum felt justified in paying. I, therefore, 
purchased it from Mr. Snyder on the 15th of August, 1891. 
The three largest dimensions of the meteorite are 11, 24, and 
334 inches and it weighed on the museum scales 847 lbs. 
Professor Clarke had a few ounces taken off for examination ; 
with this exception and the scaling of decomposed crust, from 
the outside, the mass still remains as it was found. 

Professor Clarke has kindly furnished me with the follow- 
ing analysis, made by Mr. L. G. Eakins in the laboratory of 
the United States Geological Survey. 

Professor Clarke did not succeed in developing the Wid- 
manstittian figures satisfactorily, and the small amount of 
nickel shown by the analysis would indicate a poor etching 


Am. Jour. Sci.—THIRD SERIES, VoL. XLIV, No. 263.—NovEMBER, 1892. 
28 


416 OC. &. Linebarger—Concentration of the Ions on the 


iron; when larger surfaces are available, we shall doubtless 
obtain better results. 


He Seu Tae OE aeE OS 0) 
IN ieee ee aR as a 4°81 
COR SHETES SEINE Tk A Sea eee 8 O51 
(les ee aed ai Rear CN ANE et 0°005 
I Edie Brea Cas tear a wy Piel eee et ab 0°19 
Sak RR een e: SUC eae 0:01 
99°325 


No idea can be formed of the length of time the meteorite 
had lain in the ground and very little of the amount of sur- 
face decomposition, it has undergone ;—sufficient, however, to 
remove all the finer pittings, leaving a comparatively smooth 
surface. 

Having been much interested in Mr. Davison’s examination 
of the magnetic properties of the Welland meteorite, and 
thinking that this line of investigation in other meteorites, 
might lead to interesting results, I requested Mr. Marcus 
Baker of the U. S. Geological Survey, to make an examination 
_of the meteorite, which he kindly consented to do. 

The result of this examination is to show that the meteorite, 
as a whole, acts asa mass of soft iron, gaining polarity under 
the inductive action of the earth. The lower portion on the 
north side became a north-seeking pole, while the upper part 
became a south-seeking pole; a pretty distinct neutral line was 
shown, inclined to the horizon at an angle (20°-25°) which is 
approximately the complement of the local inclination of the 
dipping needle. This induced polarity shifted with each 
change in the position of the whole mass, and in general this 
shifting of the poles took place promptly though not always 
at once. Mr. Baker also states that his observations suggested 
the probable existence of an unequal distribution of perma- 
nent magnetism, but this matter requires further investigation. 


Art. LIV.—On the Influence of the Concentration of the 
Lons on the Intensity of Color of Solutions of Salts mm 
Water, by C. E. LINEBARGER. 


THE color of a solution of a salt in water depends upon the 
eolor of the ions into which it is decomposed by the act of 
solution as well as the color of the salt itself. If the salt is 
colorless and contains but one colored ion, any circumstance 
tending to increase the number of dissociated ions, tends to 
intensify the color of the solution. If the salt is colored and 


Intensity of Color of Solutions of Salts in Water. 417 


contains one or more colored ions, the colors of the salt and 
the ions will mix, and the solution will have an intermediate 
color. Any circumstance causing a change in the state of dis- 
sociation of the dissolved salt will change the character as 
well as the intensity of the solution. 

Of course, the more concentrated the solution of a salt, the 
more intense its color; but there is another way by which the 
color may be rendered more intense, while the concentration 
of the salt, i.e. the amount of salt to fixed amount of water, 
does not change at all. This consists in heating the solution. 
Abundant experimental proof of this statement is found in an 
investigation by Gladstone,* “On the Effect of Heat on the 
Colour of Salts in Solution,’ which was published in 1857. 
Let us see why this change of intensity of color should take 
place in heating a solution. 

It has been found that the electrical conductivity of solutions 
of salts increases as the temperature rises, about 2 per cent 
for each degree of temperature. In the light of Arrhenius’s 
electrochemical theory this means that salts in solution become 
more and more decomposed into their ions as the temperature 
rises; the higher the temperature, the more concentrated the 
solution with ions. Accordingly, as the intensity of the color 
of a solution depends in a great measure upon the number of 
ions contained in it, if a colored solution be heated, its color 
deepens. 

Gladstone’s paper commences with these pregnant sen- 
tences :—“ As a general rule, the solution of a salt has the 
same power of absorbing or transmitting the rays of light at 
all temperatures. J am not acquainted with any instance of a 
dissolved colorless salt which assumes a color when the solu- 
tion is either heated or cooled; nor does the converse seem 
ever to occur,—a salt colored at the ordinary temperature, 
which loses that color when heat is applied. Nevertheless it 
is not rare to find colored salts which, when dissolved in water, 
vary in shade or in tint according to the temperature. 

In some cases, heating the solution seems merely to intensify 
the color. This is the case with the following red, orange, 
yellow, and green salts :— 


Meconate of iron—red. 

Terbromide of gold—red. 

Red nitrate of cerium. 

Bichromate of potash—orange. 
Ferrocyanide of potassium—yellow. 
Molybdous chloride—green.” 


A number of instances are now given of changes in the 
character as well as in the intensity of the color, when the 


* Phil. Mag., xiv, 423. 


418 Scientific Intelligence. 


solution is heated, the change of the character of the color 
being due, as mentioned above, to the fact that the undisso- 
ciated molecule as well as its dissociated ions are colored. 
In reference to these observations he says :—‘ A glance at the 
above observations will suffice to show that where the color is 
not materially altered in character, it invariably becomes more 
intense when heated, that is to say fewer rays are transmitted ; 
* * * The elevation of temperature seems to heighten the 
absorbent power of the dissolved salt, so that the ight absorbed 
by a certain quantity of the heated solution is the same as 
would have been absorbed by a larger quantity of the same 
solution, if cold.” 

We now know that this absorbing power is exercised by the 
ions as well as by the salt in solution, and that just as the color 
is the more intense the more concentrated the solution, so is it 
also, the more numerous the dissociated ions. And, to repeat, 
as heat increases the number of dissociated ions of a salt in 
solution, so does it deepen the shade of color of the solution. 


Nore.—Just before receiving the proof of the above paper, there came to my 
notice the articles ‘‘On the Dissociation of Electrolytes in Solution as shown by 
Colorimetric Determinations” (Chem. News, vol. Ixvi, pp. 104, 114, 141, 152) 
by H. M. Vernon. B.A., the experimental data of which afford additional proof of 
the correctness of the views expressed above. 


Chicago, Il. 


SCIENTIFIC INTELLIGENCE. 


I. CHEMISTRY AND PHYSICS. 


1. On the Relative Densities of Hydrogen and Oxyyen.— 
Ray LeicH has continued his researches on the relative densities 
of hydrogen and oxygen. In his first paper (1888) he gave 
15°884 as the ratio obtained. Subsequently he effected a direct 
synthesis of water and obtained the ratio 15°89. He says: “I 
had intended further to elaborate and extend my observations 
on the synthesis of water from weighed quantities of oxygen and 
hydrogen, but the publication of EK. W. Morley’s masterly re- 
searches upon the ‘ Volumetric Composition of Water’ (Amer. 
Jour. Sci., March, 1891) led me to the conclusion that the best 
contribution that I could now make to the subject would be by 
the further determination of the relative densities of the two 
gases... The combination of this with the number 2-0002 obtained 
by Morley as the mean of astonishingly concordant individual 
experiments, would give a better result for the atomic weights 
than any I could hope to obtain directly.” In the present ex- 
periments, the gases were obtained electrolytically, the generator 
being a long U-tube containing a solution of potassium hydrox- 


Chemistry and Physies. 419 


ide, furnished with platinum electrodes and supplied with about 
three amperes of current by means of a Grove battery. Only 
one of the gases is collected, the other being allowed to escape 
through a mercury seal. If the hydrogen is to be collected, this 
gas is led, first, through a tube of hard glass containing metallic 
copper and heated to redness, thence through a flask containing a 
strong potassium hydroxide solution, then through a second hot 
tube containing copper, through a regulating tap and a tube con- 
taining solid hydroxide, through a long tube containing phos- 
phoric oxide, and finally through glass-wool. The globe in which 
the gas is weighed is connected to one terminal of a four-way 
tube, the other terminals leading to the pump, to the generator 
and to a blow-off tube of the barometric length, respectively. 
In making an experiment, gas from the generator was allowed to 
flow through the purifying train, under the action of the pump, 
for half an hour. Then the pump was put into communication 
with the globe and with its set of tubes and a high vacuum pro- 
duced in them. On making connection with the generator the 
globe slowly filled with gas, the operation taking from two to 
three hours. The gas was allowed to escape from the blow-off 
tube for some minutes, under a pressure of half an inch of mer- 
cury. The cistern was then lowered, leaving the end of the tube 
free, and the flow of gas was continued for two minutes. Four 
minutes were allowed after the tap to the generator was closed, 
for equilibrium of pressure to be attained. Then the tap to the 
globe was turned off, the barometers and thermometers read, and 
the globe weighed. The finally corrected values obtained were 
for hydrogen 0°158531 gram, and for oxygen 2°51777; so that 
the density-ratio is 15°882. Combining this with Morley’s ratio 
of volumes 2:0002: 1, the value 15880 is obtained as the ratio of 
the atomic masses. The following summary of the results of 
different experimenters is given in the paper: 


Name. Date. Atomic masses. Densities. 
Dy umtasey eee 1842 15:96 
eomault eects me 1845 nee 15°96 
ayletohs yea. 1888 he 15°884 
Cooke and Richards, 1888 15°869 cae 
Weiser y= oe Tokio 1888 15°949 ail 
nayleio ny = ess 1889 15°89 uO 
ING VieSiiss 525. serum 1890 15°896 ees 
Ditties ee 1890 15°866 Zul ae 
Monleyen tis tae 1891 15°879 bales 
educyer ee) Sea 1891 TREE 15°905 
ayleieh, 222-222" 1892 sen 15°882 
—Proc. Roy. Soc., Feb. 18, 1892; Matwre, xlvi, 101, June, 1892. 
G. F. B. 


2. On the Properties of liquid Oxygen and liquid Air—In a 
- recent lecture at the Royal Institution, Dewar illustrated the 
properties of liquid oxygen by some remarkable experiments. 


420 Scientific Intelligence. 


Upon the lecture-table stood a liter flask full of liquid oxygen. 
On filling a test-tube with it, it appeared milky, but became clear 
on passing it through filter paper. The image of the liquid 
thrown on a screen, appeared of a pale blue color. The liquid in 
the tube boiled violently at the temperature of the air, with a 
hissing noise, giving off a white smoke due to the frozen: mois- 
ture of the surrounding air. Its boiling point, determined 
thermo-electrically, is —180°. Liquid oxygen is a non-conductor 
of electricity. Moreover, a spark 0°1™™ will not pass through it 
from a coil giving a long spark in air; so that it is also a good 
insulator. Interposed in the path of a beam of light, its absorp- ,. 
tion spectrum showed clearly the lines A and B of the solar spec- ~ 
trum, which lines as is well known, are due to absorption by the 
oxygen in our atmosphere. On accelerating the evaporation of 
some liquid oxygen by reducing the pressure upon it, Dewar 
liquefied air in an open test-tube under atmospheric pressure. 
The liquid air was clearer and fumed less than liquid oxygen. 
It also boiled more quietly. Common air liquefies at a much 
lower temperature than oxygen, both gases being liquefied to- 
gether. In evaporating however, the nitrogen boils off before ~ 
the oxygen. Placing two or three ounces of liquid air in a test- 
tube, a smoldering splinter of wood, placed in the upper portion, 
was not at first ignited. But after the nitrogen had for the most 
part boiled off, which took nearly five minutes, the wood when 
immersed burst into flame. He then poured out a wineglassful of 
liquid air and presented it to Lord Kelvin, who was in the chair. 
The magnetic properties of liquid oxygen were shown by placing 
some of it ina cup made of rock salt (in which it assumes the 
spheroidal state) and putting the cup beneath the poles of a power- 
ful electromagnet. On completing the circuit, the liquid oxygen 
rose from the cup and attached itself to the poles, thus connect- 
ing them together. There it boiled gradually away, sometimes 
more on one pole than on the other, falling back into the cup 
when the circuit was opened. With a single pole the oxygen was 
drawn up out of a tube. Compared with iron, liquid oxygen is 
about one thousandth as magnetic. Liquid air also goes to the 
poles of a magnet, there being no separation of the oxygen and 
nitrogen. It has the same high insulating power as liquid oxygen. 
Although phosphorus is not attacked on being dropped into 
liquid oxygen, yet a photographic plate immersed in liquid oxy- 
gen at —200° was found to be sensitive to light. Dewar gives 
the following boiling points under atmospheric pressure: carbon 
dioxide —80°, nitrogen monoxide —90°, ethylene —103°, oxygen 
—184°, nitrogen —198° 1°, air —192°2°, carbon monoxide. —193°, 
nitrogen dioxide —153°, marsh gas —164°. Under only 5 to 
10" 4 pressure the boiling points are for CO, —116°, N,O —125°, 
CH 21402) 0} annie ON 225 Gold) sean —207° (solid), ere) 
onite _N,O, —176°, CH, —201° (solid). —Hngineer, \xxiil, 516, 
June, 1892. G. F. B. 


Chemistry and Physics. 421 


3. On the Industrial production of Liquid Carbon dioxide. — 
In a report lately made to the Société d’Encouragement, Troost 
has called attention to the extent to which liquid carbon dioxide 
is prepared for commercial purposes, the chief use in Germany 
being in the preparation of beer and in France for the prepara- 
tion of salicylic acid by the reaction of liquid CO, on sodium- 
phenol. At the works of the Compagnie Générale des Produits 
Antiseptiques, the carbon dioxide is produced by the combustion 
of coke and is collected in a gasometer; from this it is drawn, 
dried and compressed into iron bottles under pressures of 5, 25 
and 71 atmospheres. Most of it is used in the manufacture of 
salicylic acid, though it has other uses. At present the daily 
output is 300 kilograms, but the capacity of the works is to be 
increased to 1000 kilograms. It is sold at sixty centimes per 
kilogram. It is used in making aerated waters, in the filtering 
of wine, for cooling purposes in consequence of the absorption of 
heat on vaporizing and for producing a high pressure in the 
solidification of metals.— Bull. Soc. Ene, July, 1892; Nature, 
xlvi, 399, Aug., 1892. G. F. B. 

4. On the Oxidation of Nitrogen by the Spark.—The produc- 
tion of small quantities of nitrous and nitric acids during the 
passage of electric discharges through moist air, 1s well known. 
Lrepet has undertaken an investigation to determine the precise 
nature of the chemical changes taking place, with a view of in- 
creasing the yield. The first product, when the spark passes 
through air, apparently, is nitrogen dioxide; which becomes tetr- 
oxide by the oxygen of the air. This reacts with the aqueous 
vapor, forming nitric acid and setting free nitrogen dioxide again, 
thus: (NO,),+(H,0),=(HNO,),+N,O,. On further passing the 
sparks, however, decomposition of the nitrogen oxides into their 
constituents takes place; so that in a closed space a limit is soon 
reached beyond which there is no further increase in the produc- 
tion of nitric acid. Hence the author has used a slowly moving 
atmosphere, varying the pressure and the spark through a wide 
range; and he has already increased the amount of combination 
up to ten per cent of the air employed. The best effect is ob- 
tained when the air is exposed under increased pressure to a 
series of parallel spark-discharges in the same tube. The air in 
the tube is changed intermittently, the gases passing into a large 
absorption vessel containing water or alkali-solution. In his later 
experiments Lepel has used a Topler machine having 66 revolv- 
ing plates; and he thinks that with the high voltage discharges 
lately produced by Tesla and others, the problem of producing 
nitric acid from the atmosphere may be a commercial success.— 
Ann. Chem. Phys., Il, xlvi, 319, June, 1892. G. F. B. 

5. On the Inoryanic synthesis of Azoimide.—Hitherto, azoi- 
mide N,H has been obtained only from organic substances. 
WisticEnus has now effected its synthesis from purely inorganic 
materials. His method depends upon the interaction between 
nitrogen monoxide gas and ammonia in presence of sodium, 


429 Scientific Intelligence. 


These two gases do not react upon each other even when a mix- 
ture of them is passed over heated soda-lime. But in presence of 
sodium, action readily takes place, owing to the production first 
of sodium amide, which then reacts with the monoxide to yield 
the sodium salt of azoimide, thus: NaNH,+N,O=NaN,+H,0. 
The sodium salt being less explosive than most of the other salts 
of azoimide, the experiment may be safely performed if proper 
care is exercised. The sodium in small pieces is placed in several 
porcelain boats in a combustion tube and the air is displaced 
by a current of ammonia gas. On heating the tube the sodium 
fuses and is converted into sodamide. Then the current of am- 
monia is replaced by one of nitrogen monoxide, and the tempera- 
ture is reduced to between 150° and 250° , by surrounding the 
tube by an air bath. The sodamide increases in bulk and_be- 
comes sodium azoimide, the reaction being completed when am- 
monia no longer escapes. This salt may also be obtained by 
passing a mixture of nitrogen monoxide and ammonia over 
metallic sodium; but the yield is smaller and the sodiuni some- 
times inflames in the monoxide. On throwing the product into 
water, and distilling the filtered solution with dilute sulphuric 
acid, the distillate possesses the intolerable odor of azoimide and 
gives precipitates with silver, lead, and mercurous nitrates, which 
correspond in properties with these salts of azoimide. The 
silver salt gave 71°7 per cent of silver, AgN, requiring 71°8 per 
cent. Potassium and zinc may also be used in place of sodium.— 
Ber. Berl. Chem. Ges., xxv, 2084, July, 1892; Mature, xlvi, 286, 
July, 1892. Gora 
6. On Metallic Carbonyls.—On the 3d of June, a Friday 
evening discourse on metallic carbonyls was given at the Royal 
Institution by Lupwie Monp. After referring to the potassium- 
carbonyl of Liebig as the first metallic carbonyl, he entered upon 
a consideration of the nickel-carbonyl, discovered three years ago 
by himself, in connection with Langer and Quincke. The nickel, 
prepared ina fine state of division by heating the oxalate in a 
current of hydrogen, is treated with carbon monoxide at a low 
temperature. ‘The escaping nickel-carbonyl, cooled in a freezing 
mixture, is condensed to a colorless liquid, which freezes at —25° 
in needle- -shaped crystals. The vapor has a characteristic odor 
and is poisonous. It decomposes at about 200° depositing a mir- 
ror of metallic nickel. Its magnetic properties, according to 
Quincke, are remarkable since it is diamagnetic to a high degree, 
all other nickel compounds being paramagnetic. It is also an 
excellent insulator. Its spectrum, observed by Liveing and 
Dewar, shows that it is opaque for all rays beyond wave-length 
3820. On diluting its vapor with hydrogen, the flame on burn- 
ing is bright yellowish green and gives a spectrum having a bright 
background on which are superposed a number of bands. In the 
ultra-violet fifty well-defined lines are observed corresponding 
exactly to lines in the spark spectrum of nickel. The magnetic 
rotation of nickel carbonyl, as observed by Dr. Perkin, is found to 


Chemistry and Physics. 493 


be greater than that of any other known substance excepting 
phosphorus. The atomic refraction of nickel in this substance is 
nearly two and a half times as large as in any other nickel com- 
pound. In accordance with the view that the valence of an ele- 
ment is higher in proportion as its compounds. have a higher 
refractive power, the valence 8 has been assigned to the nickel 
in nickel-carbonyl. Ferro-carbonyl is prepared in a similar way. 
It is an amber-colored liquid, solidifying below —21° to a mass 
of needle-shaped crystals, and decomposing at 180°. Its formula 
is Fe(CO),. It is permanent in the dark but on exposure to sun- 
light is decomposed, yielding a fine gold-colored solid. Experi- 
ments on a somewhat large scale to test the practicability of 
utilizing nickel carbonyl in the extraction of nickel from its ores, 
proved entirely successful.— Vature, xlvi, 230, July, 1892. 
G. F. B. 

7. Rapid Electrical Oscillations.—In the experiments by 
Hertz on electrical oscillations and also in the experiments of 
subsequent investigators, Ruhmkorf coils have been used to prop- 
agate the electrical oscillations. It is well known, however, 
that the oscillation in the sparks from a Holtz machine or a Ley- 
den jar are far more rapid than those produced by the aid of a 
Ruhmkorf coil. Torpier, therefore, has endeavored to study 
electrical oscillations by the aid of a Toepler-Holtz machine. 
His attempt has met with success and he describes his experi- 
ments at length in the paper we cite. His conclusions state the 
ratio between the primary and secondary circuits which he 
employed in order to produce the phenomena of resonance. He 
also studied the electric spark between a conductor and a surface 
of water, and discovered that this spark did not oscillate and he 
therefore concludes that it is probable that the ordinary light- 
ning discharge does not oscillate. A loud noise and strong 
development of light in an electric spark is not in general a crite- 
rion of oscillatory character of tle spark.—Ann. der Physik und 
Chemie, No. 7, 1892, pp. 464-484; No. 8, 1892, pp. 642-665. J. 7. 

8. Hlectricity of Waterfalls—Pu. LeNarp refers to the opin- 
ion formerly held upon this subject, and after an exhaustive 
examination conducted inthe Alps and also in the laboratory, 
concludes that drops of water which fall upon water or wet bodies 
develop electricity. The water is positively electrified. The air 
moves away from the place of the fall of the drops charged neg- 
atively. The charge of the water can become so great as to 
produce small sparks. The air potential in a room can become 
strongly negative. Slight impurities in the water have very great 
effect upon its electrification. A simple explanation is afforded 
by the hypothesis that contact electricity is developed between 
fluid and gaseous bodies.—Ann. der Physik und Chemie, No. 8, 
1892, pp. 584-636. Bj, Ube 

9. Photography of Color.—At a meeting of the Physical 
Society in Berlin, June 17, 1892, H. W. Voce read a paper 
on the various attempts which have been made to reproduce 


424 | Scientific Intelligence. 


natural colors by photography. He pointed out that the Lipp- 
mann process requires great care in the preparation of the bromide 
of silver emulsion in order to obtain the layer of finely divided 
silver which is essential to the success of the Lippmann process. 
Moreover there is no possibility of the multiplication of copies of 
the photograph. Each copy requires an exposure and a separate 
development. A resumé is then given of the endeavors of various 
workers to combine three negatives taken through red, yellow 
and blue glass. Later investigators employed (in 1869), red, 
green and violet. Suitable plates of the required sensibility, 
however, could not be obtained. In 1873 Vogel prepared ortho- 
chromatic plates of greater sensibility and an advance was made 
in the representation of the values of colors. Further improve- 
ment has been made in orthochromatic plates and in the method 
of using suitable color screens. What formerly could be accom- 
plished by chromo-lithography after a month’s labor by the 
employment of twenty stones can now be done in eight days with 
only three plates—Ann. der Physik und Chemie, No. 7, 1892, 
pp. 521-527. Jape 

10. Electrical Resistance of Allotropic Siluer—A. OVERBECK 
has examined the resistance of the new forms of silver discovered 
by M. Carey Lea, of Philadelphia. The latter has shown that 
allotropic silver can be converted into the ordinary silver in the 
following ways : 

1. By heating. 

Mechanical means (pressure). 
By intense light. 

4, By electrical discharges. 

5. By treatment with different acids and solutions of salt. 

Overbeck finds that all operations which tend to approximate 
allotropic silver to ordinary silver lessen its electrical resistance. 
The electrical resistance proves to be a very sensitive reagent, far 
more sensitive than any chemical process, to show differences of 
molecular state.— Ann. der Physik und Chemie, No. 6, 1892, pp. 
ae Sy ip ke 

“On the Simultaneity of Magnetic Variations at different 

ie on occasions of Magnetic Disturbance, and on the relation 
between Magnetic and Earth Current Phenomena >? by Witiiam 
Kxuts. (Abstract.)—In this paper the author refers to the ordi- 
nary variations of the magnetic elements as observed at Green- 
wich; the annual progressive change; the diurnal variation— 
large in summer, small in winter, and also larger when sun spots 
are numerous and smaller when sun spots are few; the irregular 
magnetic disturbances and magnetic storms, and the accompany- 
ing earth currents; phenomena which are generally similar at 
other places. 

He then invites attention more particularly to magnetic disturb- 
ances, Those at Greenwich may, after a calm period, arise 
gradually, or commence with great suddenness. When sudden, 
the movement is simultaneous in all elements. The first indication 


Chemistry and. Physics. 425 


may be asharp, premonitory, simultaneous movement, followed 
after a time by general disturbance, or the movement may at 
once usher in the disturbance. ‘These initial movements are not 
always great in magnitude, sometimes, indeed, small, but they 
have a very definite character, and frequently occur nearly instan- 
taneously, as is shown by the character of the photographic traces. 

It has been long known that magnetic disturbances occur at the 
same time over wide areas of the earth’s surface, but the accidental 
comparison in past years of the times of commencement of one or 
two disturbances at Greenwich with the times at other places has 
led the author to suppose that the coincidence in time is much 
closer than had been before supposed, and the definite, and on 
occasions isolated, character of the initial movement induced him 
to undertake the collection and comparison of the times of such 
movements for a number of days at observatories geographically 
widely separated. 

The times of such movements cannot be caught by eye observa- 
tion without continuous watching of the magnets, so that the 
photographic registers have to be relied upon, which is better, 
excepting that the scale of time is necessarily contracted ; but, 
though in individual measures there might be variations, it was 
conceived that (supposing no systematic error to exist) the mean 
of a number of comparisons should give a good result. Seventeen 
days occurring in the years 1882 to 1889 were selected for com- 
parison, the observatories being those of Toronto, Greenwich, 
Pawlowsk, Mauritius, Bombay, Batavia, Zi-ka-wei, and Melbourne, 
and, for a less number of days, Cape Horn (as obtained from the 
Mission Scientifique du Cap Horn,1882-83.) It was desired to 
have times for Pola, but it was found that photographic registers 
during great part of the period did not exist. The variation in 
time at each place from the mean of times for all places is given 
for each day. The mean deviation at the different places varies 
from +2°4 minutes to —2°9 minutes, the agreement between four 
of the places, Greenwich, Pawlowsk, Mauritius, and Bombay, 
being very much closer, the mean values of deviation for Green- 
wich, Pawlowsk, and Bombay differing, indeed, by only 0:1 
minute, equivalent to 6 seconds. 

The question arises, Are the differences real, or due (consider - 
ing the contracted time scale) to accidental error? If the mag- 
netic impulse is really simultaneous over the whole earth, it is a 
striking physical fact, and if not. entirely so, the circumstance is 
no less interesting; but greater attention to accuracy of time scale, 
or amore extended scale, may be necessary before the point in 
question can be definitely settled. 

A table is added, showing the character of the magnetic move- 
ment at the several observatories, from which it appears that at 
any one place the movements on different days were in most cases 
similar, though different at different places, indicating on these 
occasions the occurrence usually of one general type of disturb- 
ance. 


426 Scientific Intelligence. 


Reference is made to the question of earth currents. A com- 
parison for thirty-one days, between 1880 and 1891, of cases of 
sudden magnetic movement and earth current, shows the earth 
current to precede the magnetic movement by 0°14 minute, equiva- 
lent to 8 seconds. The question of the relation between magnetic 
movements and earth currents is discussed. The desirability of 
being able temporarily to obtain, when occasion requires, a more 
extended time scale for all magnetical and meteorological phe- 
nomena is pointed out. 

The general result is that in the definite magnetic movements 
preceding disturbance the magnets at any one place are simulta- 
neously affected ; also that in places widely different in geographi- 
cal position the times are simultaneous, or nearly so, a small con- 
stant difference existing at some places which may be real or may 
be accidental, but the character of which it seems desirable to 
determine. It is shown also that at Greenwich definite magnetic 
movements are accompanied by earth current movements which 
are simultaneous, but that neither magnetic irregularities nor 
ordinary magnetic variations seem to admit of explanation on the 
supposition of being produced by the direct action of earth cur- 
rents.— Proc. Roy. Soc., No. 313, p. 445. : 

12. Physics, advanced course, by Grorcre F, Barker, Pro- 
fessor of Physics in the University of Pennsylvania. 902 pp. 8vo. 
New York, 1892 (Henry Holt and Company.)—The subject of 
Physics has grown to so large proportions of recent years that to 
present it adequately, in systematic shape and with such thorough- 
ness as the higher grade of students demands, is a work of ever 
increasing difficulty. To the accomplishment of this task Pro- 
fessor Barker has brought a thorough grasp of the subject as a 
whole, a comprehensive and minute acquaintance with the writ- 
ings, both practical and theoretical, of the foremost workers and 
thinkers in the science, and an unusual degree of skill and 
experience in the clear presentation of facts and principles for 
the benefit of students. The results of his labors, the careful and 
patient nature of which are obvious from beginning to end, is a 
work modern in method and fresh in matter, not indeed beyond 
criticism at some points, but which commends itself to the atten- 
tion of every teacher who has to do with this department. 

Physics in general is treated as “the science of energy” and 
the three fundamental divisions adopted for the subject are those 
of (1) mass-physics, (2) molecular physics and (8) physics of the 
ether. In the first division the subjects discussed are kinematics, 
dynamics, work and energy, attraction and potential, also the 
properties of matter and finally the energy of mass-vibration or 
sound. The second part includes heat; while the third gives the 
discussion of radiation in general: of electrostatics, called the 
energy of ether-stress; magnetism, “ the energy of ether vortices” ; 
electrokinetics, “the energy of ether flow”. The last chapter treats 
of the electromagnetic character of radiation. 


Geology and Mineralogy. 427 


The above classification will serve to show the point of view 
adopted by the author, which he has systematically followed 
throughout the development of the different parts of the subject. 
There is thus a unity of general treatment which adds much to 
the value of the work. The book is also consistent in minor 
points, as in the use of the units adopted, in employing diagram- 
matic illustrations instead of pictorial representations of elaborate 
apparatus and in other respects. It is compactly printed, so that 
the large amount of matter included is embraced in 900 pages; 
the reader could wish, however, that a little less compression had 
been used by the printer at some points, for the printing of analyt- 
ical expressions in the body of the text detracts much from their 
clearness, especially as first presented to the mind of the student. 

The ultimate test of the adaptability of a text book to the pur- 
poses of general instruction must always,be its actual use in the 
class-room, and it is to be hoped that this new Physics may here 
meet with the success which the author’s careful labor makes it 
merit. 


IJ. Gerotocy AND MINERALOGY. 


i. Geological Survey of Texas, 3d Annual Report for 1891, 
EK. T. Dumpie State Geologist. 410 pp. 8vo, with maps and 
plates.—This volume, after the general Report of the State Geol- 
ogist, contains papers on Houston Co., and on a section from 
Terrell to Sabine Pass, by W. KmENNEDY; on the Llano Estacado 
with a geological map and notes on the geology of the country 
west of the Plain, by W. F. Cummines; on the Triassic in north- 
western Texas, by N. L. Draxe; on shells of a northern char- 
acter in a dry salt lake near Eddy, New Mexico, by V. Srerxr; 
on the Cretaceous of Texas, north of the Colorado River, by J. 
A. Tarr; on Trans-Pecos Texas, by W. H. Von Srrerruwirz. 
On the map of the Llano Estacado the general surface is made 
Tertiary, on the basis of the fossil Vertebrates found in surface 
deposits. In the southern part of the Plain there are Cretaceous 
beds, and beneath these and along a large part of its border, 
Triassic beds, as described by Mr. Drake. The Vertebrate 
fossils of the Llano Kstacado, here described by Prof. Cope (and 
also in the Proceedings of the Amer. Phil. Soc. 1892, p. 128), 
occur in Crosby County, in a white diatomaceous deposit, the 
so-called Blanco beds. ‘They are species of Hguus, Mastodon, 
Creccoides (a new genus of birds), and Zestudo: Equus simpli- 
cidens Cope, Mastodon angustidens (or a related species), Crec- 
coides Osbornt Cope, and Testudo turgida Cope. The Blanco 
beds are regarded as older than the Equus beds and newer than 
the Loup Fork, the latter containing Mastodon angustidens but 
no species of Hguus. The specimens described for the Survey by 
Professor Cope were collected by Mr. Cummins. 

2. Geological Survey of Alabama, by E. A. Smrru, State 
Geologist. Bulletin No. 3, On the lower gold belt of Alabama 


428 Scientific Intelligence. 


by William B. Phillips. 98 pp. 8vo, with a map. 1892.—The gold 
belt described occurs in the counties of Chilton, Coosa and Talla- 
poosa. 

3. Annual Report of the Arkansas Geological Survey for 
1892, vol. i. 152 pp. 8vo.—This volume consists of a report on 
the Iron Ores of Arkansas by Dr. Rt. A. F. Penrose. 

4. On the Osteology of Poébrotherium, a Contribution to the 
Philogeny of the Tylopoda. 74 pp. 8vo, with 3 plates: On the 
Osteology of Mesohippus and Leptomeryx, with Observations on 
the mode and factors of Evolution in the Mammalia. 104 pp. 
8vo, with 2 plates; by W. B. Scorr, College of New Jersey, 
Princeton. From the Journal of Morphology, v, Nos. 1 and 3, 
Boston, 1891.—These papers are the first and second parts of a 
Memoir bearing on questions in mammalian evolution. The 
osteological character of Poébrotherium, Mesohippus and Lepto- 
meryx are presented in detail after a thorough study of the large 
collection at Princeton, and made the basis of comparisons between 
them and the near and more distantly related species in and near 
the successional lines severally of the Camel, Horse and Tragu- 
lus. The specimens in the Museum include a nearly complete skele- 
ton of Poébrotherium labiatum of Cope, from the White River 
beds, a restoration of which is given, and also numerous bones 
illustrating the other genera, From his critical study, Prof. Scott 
draws conclusions as to the changes which took place in the course 
of development, and thence deduces principles as to “the modes 
and factors in the evolution.” His method is the only right one, 
and it is used with great caution and excellent judgment. The 
closing part of his chapter on Evolution takes up the question as 
to factors ; and in the introductory remarks he expresses his dis- 
sent from Weissmann’s theory ot the continuity of the germ- 
plasm, and says that in his opinion “so far from rendering the 
phenomena of heredity more intelligible, it tends to confuse them 
still further, and to end logically in a system very like the old 
preformationism. As Lloyd Morgan has very pithily put it, ‘I 
cannot but regard Weissmann’s doctrine of the continuity of 
germ-plasm as a distinctly retrograde step. His germ-plasm is 
an unknowable, invisible, hypothetical entity, material though it 
be, it is of no more practical value than a mysterious and mythi- 
cal germinal principle.’ Prof. Scott in summing up the results of 
his examination says, that it is clearly seen ‘‘ that transformation, 
whether in the way of the addition of new parts, or the reduction 
of those already present, acts just as zf the direct action of the 
environment and the habits of the animal were the efficient cause 
of the change, and any explanation which excludes the direct 
action of such agencies is confronted by the difficulty of an 
immense number of the most striking coincidences.” 

5. On Paleaspis of Claypole.—A paper by Mr. Claypole on his 
genus Palwaspis was read before the Geological Society of Lon- 
don on the 22nd of June. In it he “describes two specimens 
from the Onondaga group (referred to the Lower Ludlow), which 


Geology and Mineralogy. 429 


indicate the existence of a ventral plate. The fossil which he 
described as P. bitruncata is maintained to be the Scaphaspid 
plate of P. Americana.” The genus is compared with other 
Pteraspid genera, and a restoration in accordance with his con- 
clusions is given.—Ann. Mag. Nat. Hist., Oct. 1892, 334. 

6. Devonian fossils from the Jslunds and vicinity of Lakes 
Manitoba and Winnepegosis, by J. F. Wurtrraves, Canada 
Geological Survey.—Mr. Whiteaves enumerates and describes a 
large number of Devonian fossils from North-Central America 
and illustrates them with many lithographic plates. The species 
are in part identical with those of the United States. But a con- 
siderable number are new; and they are of unusual interest also 
“on account of the close relations brought out in many respects 
between the fauna of these rocks and that of the Devonian rocks 
of Europe.” The collections were made by Mr. Tyrrell and the 
author of the papers, and the localities are laid down on Mr. 
Tyrrell’s “geological map of Northwestern Manitoba, and por- 
tions of the districts of Assiniboia and Saskatchewan,” recently 
published by the Canadian Survey. 

7. J. P. Ippines: “The Hruptive Rocks of Electric Peak 
and Sepulchre Mt., Yellowstone Nat. Park.” Annual Report 
U. S. Geolog. Survey, Vol. XI1.—The writer presents the result 
of his studies on groups of igneous rocks occurring in the north- 
west corner of the Park. At Electric Peak occurs a stock of 
diorite accompanied by a great number of dikes and of sheets 
extensively intruded into Cretaceous strata. These rocks are 
described in considerable petrographical detail with tables of 
variation in structure and in chemical and mineralogical composi- 
tion. From this it is shown that the variations in all directions 
are most gradual and transitional and that it is impossible to dis- 
tinguish sharply differentiated types. The rocks of Sepulchre 
Mountain, a series of andesitic dikes cutting breccias, are treated 
with like results and the relationship of the two occurrences 
shown. Then follows a discussion of the bearing of the observed 
facts on theoretical petrography: the writer establishes that the 
same magma under differing physical conditions produce rocks 
mineralogically different. In conclusion the subject of classifica- 
tion is touched upon and the writer expresses himself in favor of 
a system based on crystalline structure. The paper is ably 
written and a most important contribution to petrographical 
literature. evens 

8. A. Saver: (Mittheilungen der Grossh. Badischen Landesan- 
stalt. II. Bd.)—In a petrographical and geological study of 
“The Granite of Durbach” the author describes a peculiar 
syenite of lamprophyric character which surrounds the granite 
as an outer zone and to which he gives the name of Durbachite. 
Particularly interesting are the author’s researches on the chem- 
ical composition of the hornblende of this syenite. This obtained 
in a state of great purity and freshness yielded 2°72 per cent of 
water by the Sipécz-Ludwig method, although over the blastlamp 


430 Scientific Intelligence. 


and heating to incipient white heat only 1:63 per cent could be , 
obtained, regard being paid to the oxidation of the ferrous iron 
present. The water being considered as basic the analysis 


Ir 
showed the mineral composed of a mixture of RSiO, and R,SiO, 
silicates and as a result of his work the writer urges that more 
attention should be paid to the determination of water in horn- 
blende analyses, since small quantities escaping determination 
may cause great differences in the molecular formule, on account 
of its low molecular weight. i Vane 

9. Danalite from Cornwall.—The occurrence of the rare min- 
eral danalite at Redruth, Cornwall, has been recently described 
by Miers and Prior (Min. Mag., vol. x, p. 10). The only speci- 
men thus far known was obtained in 1864; it shows a group of 
large reddish crystals of tetrahedral aspect which were formerly 
supposed to be pseudomorphs of garnet after tetrahedrite. The 
danalite is associated with quartz, small crystals of arsenopyrite 
and sphalerite. The hardness of translucent crystalline frag- 
ments of a columbine-red color is 5°5; the specific gravity is 
3°350. An analysis gave the results in 1, while a new analysis of 
the Schwarzenberg helvite gave the numbers in 2; from the 
latter a little fluorite has been deducted. 


SiOz FeO Mn ©7400) BeOie CaOhias 
. 29°48 37:53 11°53 4:87 1417 é. 5:04 = 102-62 

2.3383, 4:45 4443) 1492 1 62030 AON 0.7 ler 
A new occurrence of danalite from Colorado is described with 
analysis by Genth and Penfield on p. 385 of this number. 

10. Mineral Resources of the United States, Calendar years 
1889, 1890. David T. Day, Editor, 671 pp. Washington, 1892 
(U.S. Geol. Survey, J. W. Powell, Director).—The seventh vol- 
ume of this valuable series has recently been issued and like its 
predecessors gives a careful review by competent writers of the 
mineral industries of this country; the period embraced by the 
report covers the years 1889 and 1890. It is announced that the 
volume for 1891 is also well under way. ; 


Temperature of the Circumpolar region.—A short paper on 
the temperature of the Circumpolar regions, by Jules Girard, 
along with a map, is contained in the Bulletin of the Société de 
Géographie of Paris, for the 2nd trimester of 1892. It is based’ 
on the International observations durmg the year August 1882 
to August 1883, and the reports furnished by the expeditions. 
There were 15 stations occupied by the several nations—the 
United States, England, Germany, Denmark, Austria, Sweden, 
Norway, Holland and Russia—which took part in the observa- 
tions. 


mM 


NEW ARRIVALS. OF MINERALS. 


[N. B. —It is impossible for us to mention more than a few of the latest 
and more important additions. Our stock is now unequalled and cus- 
tomers can reasonably expect to have their orders filled by us for any- 
thing advertised by other houses at home or abroad and at as low or 
lower prices. | 


HERDERITE, Maine, in large crystals, a new find from a new 
localit 

ee Maine. Highly modified, green, gem crystals. 

PENFIELDITE, a new and very rare Laurium species described. in 
Sept. No. A. J.S. It occurs in small hexagonal prisms and has been 
formed during historic times by action of sea-water on the ancient slag. 
Composition PbO, 2PbCl.. It was collected by Mr. English and we | 
have all that is known. 

DIAMOND, S. Africa. Twin crystals (!) and other rare forms. 

PHENACITE, Mt. Antero. Twin crystals (!) only afew fine crystals 
are left. 
~PHENACITE, Florissant. Very complete, lenticular crystals, both 
loose and on a matrix of beautiful Amazon stone. 

GOLD, Colorado and California. A few fine crystallized specimens. ° 

RUBELLITE, California. So popular that our first shipment was 
quickly exhausted. Another and finer lot is now in, Few finds yield 
such singularly attractive specimens. 

YELLOW WULFENITE, N. M. Rarely offered so cheap or so 
choice. 

PREHNITE, Paterson. 200 fine specimens, large and small. The 
best ever found in the U. S. 


OTHER RECENT ADDITIONS. 


Topaz xls., Colo:; Amazonstone xls., Colo.; Pyrite xls., Colo. and 
Elba (twins); Autunite, Dak.; Apatite xls., Canada; Millerite, Brown 
Tourmaline, Peristerite, Diopside, N. Y.; Eudialyte x\s., Aegirite xls., 
huge Vesuvianite xls., strong Lodestone, etc., Ark.; fine Japanese 
Quartz Enclosures and Phantoms; extra choice polished Crocidolite 
(blue), Agates, Labradorite, Malachite, sections of Jasperized Wood ; 
very many of the rarest Scandinavian Minerals; very fine Sulphur 
crystals; Hawerite, Anglesite, Phosgenite, Laurionite, Fredlerite, Smith- 
sonite, Adamite, Meneghinite, Jordanite, etc., etc. 


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15 specimens of Crocoite at 50c. to $10.00. 

50 Tyrolese Epidote at 50c. to $7.50. 
30 ee Swiss Anatase at 50c. to $7.50. 
PAU Aaa Tyrolese Apatite at $1.00 to $10.00. 


The above reductions apply to all specimens of the respective min- 
erals in our stock. 


_  Dana’s New ‘‘System of Mineralogy,” only $10.00. 
100 pp. Illustrated Catalogue, 15c.; cloth bound, 25c.; Supplement, 2c. 


GEO. L. ENGLISH & CO., Mineralogists, 
733 & 735 BROADWAY, NEW YORK CITY. 


“CONTENTS: 


Art. XLIV. —Unity of fhe Glacial Epoc h: by G. F. Wricut 
XLV.—A Photographic Mcthod of Mapping the Magnetic 
Field; by C. Bb. Tuwixe 
XLV1.—Conitritations to se No. 54; 
GENTH. 

XLVIL—The Effects of Self-induction and. Distapared = 
~. Statié Capacity in a CUTE sion: ee E. BEpDELL and A,~ = = 
C. Crewore _--- Le oe 

XLVUI—The Quantitative Dete mination of Rubidium by | 

the Spectroscope; by F. A. Goocu and J. I. Parnney 
XLIX —Notes on the Farmington, Washington County, 
Kansas, Meteorite; by Il. L. Pruston—__:-.-.----2= 
_L.—A Note on the Cretaceous of Northwestern Montana ;_ : 
by H. Woop 


LI.—The Deep Artesian Boring at Galveston, Texas; by 
Ue aie A ee pee ee ree ae 
LIL.—Notice of a new Lower Oriskany Fauna in Columbia — 
County, New York; by C.. EK. Bercurr. With an an-. 
notated list of jossils; ly J. M. Crank _-.._.. . 
LII.—Description ot the Mi. Joy Meteorite ; by K. E. 
Howe. -- a 
LIV.—Infiuenice of the Concentration Ae the Ions on ae Ine 
tensity of Color of Solutions of Salts in Water; by C. 
KE. LixnerarcEr 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Relative Densities of ‘Hydrogen and Oxygen, RAYLEIGH 

_ -418—Properties of hquid Oxygen and liquid Air. l)ewar, 419.—Industr 
production of Liquid Carbon dioxide. TRoosT: (Oxidation of Nitrogen by t 
Spark. LEPEL: Inorganie synthesis. of Azoimmide, WisLiceNnus, 421. —Metal c 
Carbonyls, L. Monp 422.—Rapid Electrical Oscillations, ToEPLER: Electricity 
of Waterfalls, PH. Lenarb: F BOWetaDY of Color, H. W. VoGEt, 423.—Ele 
trical- Resistance of Allotropic Silver, OVERBECKE: - Relation between Mag 
netic and Earth Current Phenomena, Ww. ae 424. = Ens, advanced course 
 G. F. Barger, 426. 


Geology and Mineralogy—Geological Survey of Texas, H. T. feces Geoine: 
Survey of Alabama, H. A. Smirs. 427:—Annual Report of the Arkansas Geo- 
logical Survey for 1892, R. A. F. Penrose: Osteology of Poébrotherium, W. 
B. Scort: Paleaspis of Claypole, 42%.—Devonian fossils from the Islands 
vicinity of Lakes Manitoba and Winnepegosis. J. F. Watteaves: The Erupti 
Rocks of, Electric Peak and Sepulchre Mt., Yellowstone Nat. Park, J.P. IppiIné 
Mittheilungen der Grossh. Badischen Landesanstalt, A. SAUER, 429. Mee 
from Cornwall: Mineial Resources of the United pe 430. | 

Temperature of the Circumpolar sae 430. 


Chas. D. Walcott, 
U.S. Geol. Survey. 


- DECEMBER, 1892. 


BS Established by BENJAMIN SILLIMAN in 1818. 


2 


; f hs o imei oo aw x ay 
< fH KZ fA Et i 


a oo ei we ad Ce 


AMERICAN 
JOURNAL OF SCIENCE, 


_ EDITORS © : 
JAMES D. anp EDWARD s. DANA. 


ASSOCIATE EDITORS 
" Prorsssons JOSIAH P. COOKE, GEORGE L. GOODALE 
ann JOHN TROW BRIDGE, OF CAMBRIDGE. 


Prornssors H. A. NEWTON anv A. E. VERRILL, or 
New Haven, : 


poorer GEORGE F. BARKER, OF: Paice sae. 


_ THIRD SERIES. 
VOL. XLIV._[WHOLE NUMBER, CXLIV.] 
No. 264,.—DECEMBER, 1892. 


WITH PLATES IX-x. - 


. NEW HAVEN, CONN.: J. D. & E. S. DANA 
| | 1892 ; 


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, eee 
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New Mineral Species. 


Geilcielite is a titanate of magnesia from the gem washings of Ceylon. tite ex- 
cept small lots, sold to three museums, was secured. Small pieces $1 to $5.each. 

Boleite, the beautiful chloride of silver, copper and lead whose unique twins 
change our ideas as to the simplicity of the cube, is believed by the discoverer to. 
be exhausted. I secured from him nearly all that have been collected excepting a 
few which had been previously disposed of. Good cubes 10 cents to $5. The extra . 
rare twins $1 to $5. Sections for the microscope $1.25. ws 

Svabite, the new arsenate of lime described by Prof. Sjogren of Sweden, is the a 
ee species mentioned in the new Dana’s Mineralogy. ‘Groups of crystals 50 cents. : 

0 $2 eae 

Eudidymite was obtained during a week’s stay at the celebrated Langesund ae 
Fiord. This beautiful twinned beryllium-sodium zeolite is so rare that the discov- 
erer has no duplicates. Groups and contact twins: 50 cents to $5. Twin crystais 
10 cents to $2. 

Other associated minerals such as Barkevikite, Catapleiite, Hiortdahlite, John- 
strupite, Caryocerite, Leucophanite, Meliphanite, Rosenbuschite, Orangite, Wo6h- 
lerite and many others. 

Crystals of Thorite, Xenotime, Monazite, Enstatite, Kjerulfine, &c., &e., collected 
at the localities in Norway. at from 10 cents to $5 each. 

Besides the usual minerals from Nordmark, Sweden, very fine specimens of the 
ay oS ciscowered chondrodites were obtained which are offered at from 10 cents. to 

each 


Christmas Presents. 


Is your friend a collector? A specimen of Rhodonite var. Paisbergite from the 
Harstig Mine, Sweden, would be a beautiful gift. Well erystallized specimens 25 
cents to $5.00. 

Selenite erystals from Sicily, the most peautiful ever seen, 10 cents to $5. Some 


. showing sulphur and aragonite crystals in their limpid depths, 25 cents to $10. The 


Sulphur and Aragonite crystals and groups have never been equalled for their bril- 
lianey, perfection and beauty. Good specimens 25 cents to $3.50. Fine large speci- 
mens $3.50 to $10. The Calcite pseudomorphs after Aragonite are not only very 


- beautiful but also instructive, 25 cents to $5. 


Fluors; the finest lot that ever came to America; brilliant purple specimens, 
some showing crystals four to six inches in diameter up to $15; blue, yellow, green 
and other colors at any price. Also new forms and colors of Calcites and Barites. 

Collections of Minerals for boys and Be from $1 to $10 a hundred 
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THE 


AMERICAN JOURNAL OF SCIENCE 


[THIRD SERIES.] 


20 


Art. LV.—An Experimental Comparison of Formule for 
Total Radiation between 15° C. and 110° C.; by 
W. LEContvE STEVENS. | 


THE earliest attempt to express the rate of cooling of a 
heated body was that made by Newton and embodied in a 
simple formula, which states that this rate is directly propor- 
tional to the difference of temperature between the radiating 
body and the medium surrounding it. It has long been known 
that this law is only approximately true when these tempera- - 
ture-differences are small, and that it is wholly inapplicable 
when they are large. 

During the early part of the present century an elaborate 
research on the measurement of temperature and the com- 
munication of heat was made. by Dulong and Petit.* Such 
instruments as the thermopile, the bolometer, and the galva- 
nometer had not yet been invented. Their method was to 
employ as radiating body a large thermometer whose bulb con- 
tained more than a kilogram of mercury. This was placed with- 
in an envelope which was kept at constant temperature and made 
nearly vacuous as quickly as possible after the introduction of 
the heated bulb. The rate of cooling was found to bea fune- 
tion of the temperature of the envelope, the latter being kept 
constant during any given experiment, but varied for different 
experiments. For a given difference of temperature between 
the bulb and its enclosure it was found that the rate of radia- 
tion increases very nearly in geometrical progression while 
that of the enclosure increases in arithmetical progression. If 


* Annales de Chimie et de Physique, vol. vii, 1817. 
AM. JOUR. ScI1.—THIRD SERIES, VoL. XLIV, No. 264.—DEcEMBER, 1892. 


432 W. LeConte Stevens— Experimental 


S represent the quantity of heat radiated in unit of time, @ the 
temperature of the enclosure, 7 the excess of temperature of 
the radiating body over that of the enclosure, @ a constant 
whose value they determined to be 1:0077, and m another con- 
stant whose value depends on the nature of the substance and 
the condition of its surface, the law of Dulong and: Petit is 
expressed by the formula 


S = m(a)°(a'—1) (1) 


In order to compare this formula with others presently to be 
given, it will be best to express @ and ¢ in terms of absolute 
temperature. Letting T stand for the absolute temperature 
of the heated body, and T, that of the enclosure, we have 
é= T,—273, and¢=T—T,. The formula now becomes 
Si (MeO O77) Rome (OOM meme) (2) 

The range through which the value of T—T, was varied in 
these experiments was 240° C., while the temperature of the 
enclosure was varied from ()° to 60° C. . 

Subsequent investigators have tested the formula of Dulong 
and Petit, and have found that although it may seem to cor- 
respond nearly to the truth within the limits selected, it gives 
very erroneous results at higher temperatures, the radiation 
revealed by measurement being much less than that which is 
calculated by means of the formula. De la Provostaye and 
Desains tested it with thermometers whose bulbs were covered 
with a plating of metal, and found that under this condition 
the factor, 7, varies with the temperature.* Draper, Tyndall, 
and Ericsson have published researches which showed the 
insufficiency of Dulong and Petit’s formula. This formula 
may therefore be considered now as of only historic interest. 

In an exhaustive comparison of the work done by these 
physicists, Professor Stefan, of Vienna, proposed a formula 
which, like those that preceded it, is empirical, but which cor- 
responds much more nearly to the results of measurement 
than does that of Dulong and Petit.+ He found that the 
amount of heat emitted in unit of time was proportional to 
the fourth power of the absolute temperature ; or, in the nota- 
tion already employed, 

Siva (3) 


Since there is an exchange of heat between the radiating body 

and the surrounding medium, the effective radiation is 
S=mT'—mT, 

This is obviously reducible to the form 


* Ann. de Chimie et de Physique, III, xvi. 
+ Sitzungsberichte der K. Akademie der Wissenschaften, Wien, lxxix, 1879. 


Comparison of Formule for Total Radiation. 433 
Ais 
fs) = 708 ie - 1) (4) 
This formula has the advantage of great simplicity and ease of 


application. 

Almost simultaneously with the publication of Stefan’s 
paper in Vienna appeared an experimental research on the 
temperature of the sun, by M. F. Rosetti, of Padua.* Rosetti 
employed the thermopile and. oalvanometer for measuring 
the radiation from a Leslie cube covered with lamp-black 
and filled with water, which was stirred in order to secure 
uniformity. Tor temperatures between 100° and 300° mer- 
cury was substituted for water. In the liquid were immersed 
the bulbs of two thermometers whose readings gave the mean 
temperature at any selected moment. For still higher temper- 
atures a copper ball was heated to redness, then exposed at a 
fixed distance in front of the thermopile long enough to pro- 
duce a galvanometer deflection, and immediately afterward 
thrown into a calorimeter. The specific heat of copper being 
known, it becomes possible to compute the temperature of the 
ball at the moment of its immersion in the water. From 
these and other experiments Heese was led to adopt the 
empirical formula, 

S = aT*(T—T,) —0(T—T,) (5) 

Here a and + are two constants whose values for the particu- 
lar instruments he employed were determined to be @= 
000000335131, and 6 = 0:0636853. Rosetti considered the 
first term of his formula to represent the heating effect if the 
body were radiating in a vacuum, and the second term to rep- 
resent the radiation of the air in which the body is immersed. 
Comparing this with Newton’s formula, 

S= a(T—T,), 
it is seen that while Newton regarded the emissive power, @, - 
as independent of temperature, Rosetti regarded*it as propor- 
tional to the square of the absolute temperature. 

The accordance between the results of experiment and of 
calculation by means of this formula, as published by Rosetti, 
are quite remarkable, though the experiments seem lable to 
some criticism. . Any assumptions regarding the uniformity of 
temperature in a Leslie cube are subject to challenge, if the 
water be not kept boiling. The calculations of temperature 
from calorimetric measurements is usually affected with a large 
probable error. For temperatures higher than those employed 
in calorimetry Rosetti. used small disks of metal which were 
rendered incandescent in the hottest flames at his command, 


* Annales de Chimie et de Physique, V, vol. xvii, 1879. 


434 W. LeConte Stevens— Experimental 


and their radiation while thus glowing was measured by means 
of the thermopile. Finding his formula apparently satisfae- 
tory, he assumed it to be applicable to yet higher temperatures. 
Exposing his thermopile to the sun and comparing the deflec- 
tion thus obtained with that given by a body of known temper- 
ature and area, at a known distance, the temperature of the 
sun was computed to be about 10,000° C. The work done by 
Rosetti was valuable; but his formula, involving two unde- 
termined constants which vary with every thermometric instru- 
ment employed, may be considered, like that of Dulong and 
Petit, as of little more than historic interest. 

In [888 an important communication regarding the radiation 
of solid bodies was given to the Berlin Academy of Sciences 
by Professor H. F. Weber, of Ziirich.*. He had been engaged 
in an extended investigation of incandescent electric lamps for 
the purpose of finding, if possible, a general formula for the 
relation existing between the quantity of light emitted, the 
area of the radiating surface, the quality of the substance 
raised to incandescence, and the amount of electric energy 
expended. Among the results attained was the establishment 
of a formula expressing the relation between the intensity of 
any selected homogeneous radiation, the corresponding wave 
length, the temperature, and the quality of the radiating sub- 
stance. An indispensable factor in the determination of this 
formula was the previous admirable work of Langley on radia- 
tion from the sun and various terrestrial sources, expressed in 
an energy curve which is now familiar to all physicists. From 
the study of this energy curve and of all other published 
results that were accessible, as well as his own experiments, 
Weber obtained the following formula: 

1 
1 pre 
IN 

Here 7 denotes the absolute temperature of the radiating 
body, expressed in degrees centigrade, 4 the wave length of 
the homogeneous radiation considered, / the area of the 
radiating surface in square centimeters, e the base of the 
Naperian system of logarithms, and s the amount of energy 
radiated by the body in all directions in unit of time. The 
constant, c, depends on the nature of the radiating surface; it 
is the ‘‘emission constant.” The constant b° depends also on 
the nature of the radiating body. Its mean value, as deter- 
mined from a large number of experiments has been found 
to be 


Si c7nn 


P= OG SO 
* Sitzungsberichte der K. Akademie der Wissenschaften, Berlin, 26 Juli, 1888. 


Comparison of Formule for Total Radiation. 435 


To determine the value of the constant a, experiments were 
made upon a variety of solid conductors, including carbon, 
platinum, iron, and copper, raised to incandescenee. For each 
of these the same value was found, 
a = 0°0043 
if it be desired to find the total radiation, rather than that 
of a single wave-length, the equation just given must be inte- » 
grated between the limits A=VandA=«. We have then 
for the total radiation, S, 


S=/ sdd 


The resuit of the integration is 
oh T 
S=41,/x cbFe T 


Or, letting C represent the total emission constant, dn/m cb, we 
have 


aT 
Se (Oing Fal 
If the radiating body be surrounded by another body whose 
constant absolute temperature we may call T,, there is mutual 


radiation between the two, and the resultant radiation of the 
first becomes 


0 


aT aT 
re (O)0G A XOlnae Ah 


This is obviously reducible to the form 
iad) 
ap © -1) 

Here the quantity outside of the parenthesis is made up of 
constants, and the variation of S is dependent only on T. 
For purposes of comparison therefore we may employ only 
what is found within the parenthesis. 

This formula has been tested by applying it to the results of 
experiments already published by Schleiermacher, Graetz, and 
Magnus in Germany, Bottomley and Tyndall in England, 
Violle, Garbe, Becquerel and Mouton in France, and Langley 
and Nichols in America. A part of these results were in- 
cluded in the communication to which reference has already 
been made. 

In testing Stefan’s formula* Schleiermacher measured the 
loss of energy sustained in unit of time by a platinum wire, 
heated to a given temperature within a good vacuum by means 
of the electric current and surrounded by an envelope kept at 


aT» 
S = CFe Tl 


* Wiedemann’s Annalen, xxvi, p. 287. 


436 W. LeConte Stevens— Kuperimental 


a lower fixed temperature. The temperature of the wire was 
deduced from the variation in its resistance. The result was 
to show that for low temperatures Stefan’s formula gives 
results that are too great, and for high temperatures they are 
too small. The application of Weber’s formula to Schleier- 
macher’s data yields results that are more consistent. 

The following experiments have been made with a view to 
comparing the formulas of Dulong and Petit, Rosetti, Stefan 
and Weber in their application to temperatures but little 
removed from that of the atmosphere, not employing the 
indirect method of Schleiermacher, but measuring tempera- 
tures directly with the thermometer and radiation with the 
thermopile. 

The radiating body was a metallic disk instead of the Leslie 
cube. A hole was drilled into it, parallel to one of its flat 
surfaces and extending nearly to the center. This was for the 
reception of a thermometer. The disk couid therefore be 
raised to any desired temperature within the range of the ther- 
mometer, and its temperature be noted at any moment while 
it was cooling. One face was kept always scrupulously clean 
and smooth so as to prevent variations in emissive power. This 
face was turned toward a thermopile at a fixed distance from 
it. The thermopile was enclosed in a donble-walled box of 
sheet brass for the purpose of preventing draughts and other 
disturbances that might affect its temperature. Through the 
cover of this box a delicate thermometer was passed, so that 
its bulb rested almost in contact with the thermopile. Varia- 
tions of temperature within the box were thus measurable to 
within a hundredth of 1° C. In the end of the box turned 
toward the disk was a circular opening, 7 in diameter, pro- 
vided with a double-walled adjustable brass cover. This was 
controlled by means of a string so that the thermopile could 
be exposed to radiation for a brief interval and then shut off 
from this. The thermopile was connected with a very delicate 
mirror galvanometer of low resistance, and all readings were 
taken by means of telescope and scale. The sensitiveness of 
this galvanometer was tested from time to time by putting it 
in cireuit with a standard Clark cell and a resistance of 72,000 
ohms. Around the suspended disk, except on the side toward 
the thermopile, double brass screens were placed, and a screen 
also above the space between it and the box. Disturbing air 
currents were thus avoided, not completely, but as far as pos- 
sible. The entire apparatus was in a basement room whose 
‘temperature remained very nearly constant from day to day. 
A thermometer, hung outside of the brass screens, permitted 
comparison between the temperature of the room and that 
within the box containing the thermopile. 


Comparison of Formule for Total Radiation. 437 


Before beginning any one series of observations, readings 
were taken from each of the three thermometers. These had 
of course been previously compared and found reliable, so 
that the correction for -difference’ between them was very 
small. The disk had been hanging in position for some hours, 
but on exposure the thermopile always indicated a slight dif- 
ference of temperature between itself and the disk, amount- 
ing to one or more scale divisions. This deflection was 
recorded, to be used as a correction to subsequent readings. 
The disk was then removed, heated up to a given temperature 
in excess of any to be measured, and hung again in position. 
After a few minutes its temperature was noted, the thermopile 
exposed long enough only to produce a throw of the galva- 
nometer needle, the temperature of the disk immediately 
again noted, and also the temperature of the thermopile as 
indicated by the thermometer in the box. This procedure 
was repeated at intervals of two minutes during one or two 
hours, in which the disk became cooled down to a temperature 
differing but little from that of the room. 

The arrangement of apparatus and the procedure just de- 
scribed was that finally adopted after many days had been 
spent and many hundreds of observations taken which had 
failed to yield satisfactory results. With the utmost care it is 
impossible to exclude air currents from the disk, and hence 
irregularities in its radiation. The same remark would apply 
equally to the Leslie cube, with the additional consideration 
that convection currents within the cube during its cooling 
would be very hard to control, even with assiduous stirring. 
At each exposure of the thermopile the air around it becomes 
warmed slightly by the disk, and it cannot be assumed that the 
temperature of the room is that of the thermopile after the 
first few exposures have been made. By enclosing the instru- 
ment in a box, this warm air, it is true, is prevented from 
passing away; but this disadvantage is much more than offset 
by the possibility of measuring and recording the increase of 
temperature, for which a curve of corrections is afterward 
made. 

To continue any one series of observations until the differ- 
ence of temperature between disk and thermopile vanishes is 
obviously impossible. Even when this difference amounts to 
several degrees disturbances are apt to produce such irregu- 
larities in the indications of the thermopile as to introduce 
serious error. By artificially cooling the disk until it seemed 
to indicate the same temperature as the box it was found that 
uncontrollable errors were introduced. It was best therefore 
to allow the cooling by radiation to continue until a tempera- 


ture-difference of 5° or 10° remained, recording the corre- 


438 W. LeConte Stevens— Hxperimental 


sponding deflections at the usual intervals. To find out what 
would be the residual deflection, if this temperature-difference 
as indicated by the thermometers were reduced to zero, advan- 
tage is taken of the fact that for such small differences the 
curve expressing the radiation is approximately a straight line. 
Taking therefore the recorded small temperature-differences 
as abscissas and the corresponding deflections as ordinates, a 
straight line is drawn through the points thus found. Pro- 
longing the line in a negative direction until it cuts the axis 
of ordinates, the distance of the point of intersection above 
or below the origin gives the correction to be applied to these 
final readings. The correction to the initial readings having 
been taken before heating the disk, ahd the slight variation of 
temperature in the box having been recorded, we have the 
means of constructing at least an approximate curve of cor- 
rections for all intermediate readings. 

It is scarcely necessary to add that all thermometer readings 
were corrected for the difference of temperature between bulb 
and tube, and that all scale readings were reduced to those 
which would have applied to a cireular are. 

The disk employed in the majority of the experiments was 
made of iron, though a number of measurements were made 
also with one of copper of the same dimensions. The distance 
from disk to thermopile was kept constant for each single series 
of observations, but this distance was varied from 30 to 
40° according to necessity, and the sensibility of the galvan- 
ometer likewise varied, for different ranges of fall of tempera- 
ture. The superior conduetiv ity of copper ensures quicker 
equalization of temperature throughout the disk of this metal, 
but that of iron is amply sufficient, while its higher coefficient 
of emission makes the experiments less tedious and less subject 
to error than when a disk of copper is employed. The disk con- 
stitutes a short cylinder whose radius is 7 = 73°" and whose 
length is 22 = 1-4™ or the distance from center to flat surface 
of the cylinder is? =0:7™. It can be shown* that if a ther- 
mometer bulb be placed within such a cylinder of heated iron at 
its center, and if it be assumed that a brief interval of time, such 
as one minute, has elapsed, then between the center of the 
disk and the nearest point on its face, at a distance of 0-7" the’ 
absolute temperature does not vary more than 0:0002 of itself, 
or 0°02 of 1 per cent; also that the temperature: difference 
between center and circumference of the flat surface, an inter- 
val of 7:3°", does not exceed 0°18 of 1 per cent. It is safe to 
assume therefore that no error so great as the necessary errors 
of observation can be introduced by accepting the temperature 


* Lectures of H. F. Weber on the Theory of Cylinder Functions and their appli- 
cation to the Problems of Physics. 


Comparison of Formule Jor Total Radiation. 439 


indicated by the thermometer as the temperature of the radia- 
ting surface. 

The method of work and the degree of accuracy attained 
may now be further illustrated by tabulating some of the 
results. 

Tables I and II exhibit two independent series of measure- 
ments, on a fall of temperature through 40° C., the initial tem- 
per atures being approximately 60° C. as shown. For con- 
venience the tables are arranged in the order of the intervals of 
time included in each, rather than in that of increasing tem- 
perature-difference which would on some accounts be prefer- 
able. The measurements were on the radiation of the iron 
disk. For the series indicated by Table I the initial deflection 
obtained before heating the disk was 0,= +03 scale division. 
The disk was then heated up to a temperature a little in excess 
of 60° and hung in position. While it cooled down to 21°°6 a 
series of 57 observations were made at intervals of two 
minutes. The residual correction was then found to be 
0,= —2°0 scale divisions. The sensitiveness of the galvanome- 
ter remained unchanged during the i114 minutes of work, while 
the temperature within the box was raised from 16°16 to 
16°72. For the purpose of tabulation the absolute tempera- 
tures, time intervals, and corresponding galvanometer deflec- 
tions were obtained by interpolation for intervals of 5° in suc- 
cession, after all necessary corrections had been applied to the 
recorded readings. The horizontal column H gives the hour and 
minute at which the record thus obtained should have been 
made. Column 1 gives the absolute temperatures of the 
disk, T, those of the thermopile, and T — T, the temperature 
differences. Column E gives the experimental. result in radia- 
tion, as obtained in scale divisions of deflection. Column W 


gt—To)_ 


gives the numbers for 1), which is the factor 


T 
involving the variable, ait in Weber’s formula. Column § 


; 


a 
gives the numbers for (5 :—1), involving the same variable 
0 


in Stefan’s formula. Each number thus obtained by formula 
is then divided by the corresponding values of E in the same 
vertical column obtained by experiment. The quotients are 
arranged in the horizontal columns W ~ E and § ~+ E respec- 
tively, and multiplied by a power of 10 for the purpose of 
avoiding inconvenient decimals. This has no influence since 
our object is only that of comparison. Ifa formula be cor- 
rect, and if the measurements be free from error, the numbers 
contained in the corresponding horizontal column of quotients 
should be identical. If they progressively i increase or decrease 


440) 


W. LeConte Stevens— Experimental 


through the series, this shows that the formula gives results 
that are progressively too high or too low, as the case may be. 

The explanation just given applies equally to Tables II, III 
and IV, the last two of which represent a fall of temperature 
through 80°. 


E 
WwW 
S 
W+E 
S=H 


gh 33m 


RSD ole 
aon & 


Mrmr ow 

OO wm qwlO oo 

BRrASLZwWAS 
WwW orang 


1oh 39m 
375°30 
290°30 


85 
376°0 
0°865 
1°803 
230 
480 


CO FF 
bo bo 
oor 


OM Hy 


TABLE I. 
gh 45m gh 53m 
319°33 314°43 
289°33 289°43 
30 25 
264°6 218°6 
0:255 0-210 
0-485 0:°392 
964 960 
183 179 
TABLE II. 
10h 5m 10813 
31832 313°46 
288°32 288°46 
30 25 
271°0 221°9 
0°255 0:210 
0-485 0°392 
941 946 
179 Ure 
TABLE IIT. 
104 30™ 105 36~ 
35440 344°49 
289-40 289°49 
65 55 
214:2 175°0 
0-619 0°508 
1-249 1-006 
289 290 
583 575 
TABLE IV. 
108 45™ 10) 54m 
355°43 345-50 
290-43 29050 
65 55 
206°2 2182 
0619 0:508 
1:249 1006 
UB 233 
469 461 


10h 3m 
309°52 
289-52 


20 
1710 
0°165 
0°306 
965 
ef) 


20 
173°7 
07155 
0°306 
950 
176 


104 44m 
33457 
289°57 


45 
138°7 
0-403 
0-780 
290 
562 


304°61 
289°61 
a) 

1266 
0-122 
0°225 
964 
178 


LOM 2A S10RSS™ 
308-63 
288°63 


303°82 
288-82 


TON T9= 102 38m 


105 59™ 


299-00 
289-00 
10 
84-7 
0-080 
0-145 
945 
Miial 


Y1higm 
314:70 
289-70 
25 
712-2 
0-210 
0°392 
291 
543 


112 1g™ 
294-72 
289-72 


5 


41°3 
0-040 
0-069 
968 
167 


113i 
294-13 
289-13 


5 


42-0 
0-040 
0-069 
952 
164 


TL Be 


TP 2m 112 ow 1 2iesnagm 


335°61 
290°61 


45 
173°0 
0°403 
0-780 
233 
451 


325°68 
290°68 
35 
129°5 
0-302 
0°578 
233 


446 


315-71 
290°71 
25 
89°8 
0-210 
0°392 
234 
437 


If now each one of the series of numbers in column W = E 
or S + E be divided by the mean of the series the successive 
quotients will differ but little from unity. 
horizontal column of results we may call the column of devia- 


tions. 


The corresponding 


If the numbers in this column be represented by a curve, 


with temperature-differences for abscissas, this curve should be 


Comparison of Formule for Total Radiation. 44] 


very nearly a straight line parallel to the axis of abscissas. It 
will be most convenient to arrange such a series therefore in 
the order of increasing temperature-differences, which is the 
reverse of that in the tables just given. Any irregularities in 
the curve must be due to the errors of experiment, and partly 
to the fact that logarithmic results are only approximations. 
Table V is made up of the deviation columns from five inde- 
pendent series of observations ranging through 40°, to which 
Weber’s formula has been applied. Table VI contains the 
application of Stefan’s formula to the same series. 

Table VII shows Weber’s formula, and Table VIII Stefan’s 
formula, applied to six independent series of observations 
ranging through 80°. In each case the mean of each vertical 
column is shown. 


TABLE V.— Weber. 
T—T) 5 10 15 20 25 30 85 40 45 
I 0°983 0-989 1005 1°007 1:007 0°997 1001 1:007 1:007 
ale 1008 0°998 1:013 1°004 1000 0993 0°992 0:°993 0°999 
III 1:006 O02 10:998- 1-003 0-998 1-001 0:995 0:997 0°999 
1V sexes 1001 1-006 1:006 1006 0°994 0:993 1:002 0°994. 
V era 1:002 1:009 1:01] 0:996 0:°996 0996 0996 0:997 


Mean 0-999 0998 1006 1006 1:002 0996 0995 0999 0999 


TaBLE VI.—Stefan. 
T—T, 5 10 15 20° 25 30 35 40 45 
i 0°906 0:971 0-991 0°998 1:008 1012 TOR TO) 1:046 
II 0:928 0-980 0:998 0:°995 1000 1:008 1017 L025 1:045 
Ili 0°928 0:987 0°988 0-995 0:999 1:016 1°021 1:007 1:039 
IV eel 0:973 0 983 0989 0-997 1-000 1-009 1:043 1:024 
V lets 0977 0°986 0:993 0-988 1°002 1012 1:020 1°026 


Mean 0:92 OSs 02989) 0:99455 70.998 008s WOM le O23p5 1036 


TABLE VII.— Weber. 
RT 15 25 35 45 55 65 "5 85 95 

I 0:993 0977 0-997 1001 1014 1024 5 0:992 1:006 0:996 
II 10045 12006 1:005 1:004 1:003 0°999 0:996 0-988 0°996 
Ili 1014 =1°009 1:003 1:002 07999 0°993 0:990)0:9935)50:995 
IV 0°997 1011 1:002 1002 0-997 0:990 1014 1/001 1:017 
V 0-999 1001 1:004 1:003 1:002 1001 0°995 0:991 0°996 
VI Bed et Bs 1-000 1001 1:001 1:001 0°999 0:998 ds ayy 


Mean EO Oil 0 Ole Salk OMe ele O 0 2tuialc O02 OOM O99 SHO: 996.: 16000 


TaBLE VIII.—Siefan. 
T—T) 15 25 35 45 55 65 


0D 85 95 

I O92 De O92 2s O96o sOc9On Olay als OL4) lO Wl OoO swe OG: 

10g O;93i- 0949 = 20-903 es O983re le O0b wel OI MeOk2i G04 e063 
iil 02945005953) 10/971 O9SIR L000) TOS O26) OAT 064 
IV 0;926) 50:951) 0:966) 10:90 0995) 1006) 1-046> 160515 1:083 
Vi O93 105950 0:92) 0-982 10037) LO 2 L030; wal U42 snl 065 
VI eet ate Named ae? O95 OO: 90) MOL993) ha O24 nite O 24) Mel: 04/2 aig pes ok 
Mean 0-933 mm O94 OO. 6S ee Ono Oe 002 ane OO IOs POA mene OGS 


442 W. LeConte Stevens— Haperimental 


The mean results of Tables VII and VIII are expressed 
graphically in the curves of fig. 1. Here it is seen that 
Weber’s formula is expressed by a curve (WW) nearly parallel 
to the axis of abscissas, but with shght irregularities, as might 
be expected in any representation of experimental results. At 
no point is the deviation so great as 0°5 of 1 per cent. - Stefan’s 
formula is expressed by a curve (SS) which is plainly oblique 
to the axis of abscissas, the greatest deviation being more than 
6 per cent. These experiments therefore confirm the result 
otherwise attained by Schleiermacher, indicating that for tem- 
peratures but little above that of the atmosphere Stefan’s 
formula gives a rate of increase of radiation that is too rapid, 
while Weber’s formula coincides very closely with the results 
yielded by experiment. 

Fig. 1. 


1:080 
1:060 
1°040 
1020 
1-000 
0°980 


0°960 


15 25 35 45 55 65 "5 85 95 
Curves of deviation for formulas of radiation for temperatures from 30° to 110° C. 


It may be of some interest in this connection to exhibit the 
application of these formulas to a wider range of temperature 
difference. For this purpose the constants of each formula 
have been determined from the data contained in the tables 
just given ; those of Rosetti’s formula being obtained by method 
of least squares. In fig. 2, the abscissas represent temperature 
differences from 0° to 800° C., the temperature of the thermo- 
pile being taken as 17° C., which was the mean temperature of 


Comparison of Formule for Total Radiation. 443 


the room in which the measurements were made. The ordi- 
nates are to be read in units of deflection on a scale such as 
was employed in the galvanometer readings representing 
radiant energy. or temperature-differences less than 100° 
these curves are nearly coincident. For high temperatures 
Stefan’s formula gives results that are higher than those of 
Weber's formula; but the rate of increase by Weber’s formula 
rows more rapidly, and for a temperature difference of about 
720°, about that of red heat, the two curves cross each other, 


Fig. 2. 


100 200 300 400 500 600 00 800 
Curves of radiation for temperatures from 17° to 817° ©. 


D. Curve for formula of Dulong and Petit. 


W (73 a3 33 6c Weber 
S 74 a3 3 46 Stefan 
Ie) mae OC ub ‘* Rosetti. 


and, from this point on, the indications of Stefan’s formula 
become lower than those of Weber’s formula. In this connec- 
tion we may again refer to the experiments of Schleiermacher, 
who, by estimating change of temperature through variation of 
electrical resistance, found the indications of Stefan’s formula 
to be less than the results obtained by experiment. The curve 
of Rosetti’s formula gives a rate of increase in radiation that is 
about as much too low as that of Dulong and Petit is too high. 


444 M. Carey Lea—Notes on Silver. 


Art. LVI.—Wotes on Silver; by M. Carry LEA. 


Action of Ammonia.—Aqueous ammonia is supposed to be 
without action on normal silver but this is not so: under favor- 
able conditions, silver is gradually taken up by this solvent. 

The first experiments were made with silver reduced from 
the nitrate by the action of sodium hydroxide and milk sugar. 
The silver was very carefully purified from any possible trace 
of oxide. Placed in contact with ammonia for a few hours, 
silver was taken up. Its presence could be recognized either 
by ammonium sulphide or by adding a drop or two of hydro- 
chloric acid and then supersaturating with dilute sulphuric acid ; 
a dense cloud of silver chloride forms and this result can be 
obtained any number of times in succession by acting with 
ammonia on the same portion of silver. 

A similar reaction was obtained with silver reduced from 
chloride by cadmium and hydrochloric acid removing afterwards 
ail traces of cadmium. Silver reduced in this way is liable to 
contain traces of chloride. These were removed by covering 
the silver with strong ammonia, letting it stand over night and 
thoroughly washing out. This was repeated five times. From 
this silver, ammonia by twenty-four hours contact always took 
up enough to give a dense white cloud when treated as above. 

Portions of solutions obtained in the last mentioned manner 
were evaporated to dryness over the water bath and left brown- 
ish black films. These were non-explosive and therefore did 
not consist of silveramine: they yielded a large proportion of 
silver to acetic acid, leaving behind a little metallic silver. 
The ammonia therefore, does not dissolve the silver as metal 
but as oxide. The presence of a little metallic silver in the 
residue left by evaporation was probably due to slight traces of 
oxidable organic matter contained in the ammonia. This opin- 
ion was confirmed by the fact that the solution when heated 
acquired a transparent red color. 

It appears therefore that in the presence of ammonia, silver 
has a tendency to oxidize, for when the silver was placed in a 
vial with an air-tight fitting stopper, filling it about half full, 
and was then completely filled with liquid ammonia and tightly 
closed, it was found that in twenty-four hours a mere trace of 
silver was taken up. On the other hand when the silver was 
placed in a flat basin and merely moistened with ammonia 
more silver was taken up in five minutes than in the preceding 
case in twenty four hours. 

This action of ammonia in promoting oxidation recalls its 
behavior with cobaltous salts and with copper. It is probably 


M. Carey Lea—Notes on Silver. 446 


the only ease in which silver is oxidized (at ordinary tempera- 
tures) by atmospheric oxygen. 

Action of Dilute Sulphuric Acid.—lt is generally held that 
silver is insoluble in cold dilute sulphuric acid. Almost any 
form of silver, providing it is finely divided, is slightly soluble 
in sulphuric acid diluted with four or five times its bulk of 
water. With more dilute acid different varieties of silver act 
very differently. The most easily attacked is that which is 
obtained by reducing the oxide with alkaline hydroxide and 
milk sugar; from this a distinct trace is dissolved by sulphuric 
acid diluted with 100 times its bulk of water. From silver 
reduced from the chloride by cadmium this very dilute acid 
takes up nothing. 

Nitric acid, sp. gr. 1:40, diluted to ten volumes and allowed 
to stand for an hour with finely divided silver, took up an ex- 
tremely faint trace. 

Hydrochloric acid, sp. gr. 1:20, was totally without action. 
The silver after being well boiled with water to remove every 
trace of acid, dissolves completely in nitrie acid. 

Acetic acid has no action upon metallic silver. 


Various Reactions of Normal Silver. 


Normal metallic silver even in a state of very fine division 
does not abstract the slightest trace of nitric acid from perfectly 
neutral cupric nitrate obtained by acting on pure cupric sul- 
phate with barium nitrate. After fifteen hours of contact not 
a trace of silver had been dissolved. 

But silver easily reduces cupric chloride with formation of 
purple photochloride. If the copper salt is present in slight 
excess the silver is so thoroughly acted upon that nitric acid 
does not extract a trace of it from the purple photochloride. 

Metallic mercury instantly reduces silver nitrate but metallic 
silver takes chlorine from corrosive sublimate. The precipi- 
tate contains calomel and blackens with ammonia. 

Silver in fine division slowly reduces a neutral solution of 
potassium permanganate. 

Silver nitrate, as is well known, is reduced by ferrous sul- 
phate, or ammonia ferrous sulphate, the iron at the same time 
becoming peroxidized and the silver assuming the gray metallic 
form. On the other hand silver powder rapidly reduces a nen- 
tral solution of ferric sulphate. A solution of iron alum 
readily dissolves metallic silver without the aid of heat;* ina 
few seconds the solution strikes a blue color with potassium 

* The statement in the new Encyclopédie Chimique that heat is required and 


that the metal separates again on cooling (Tome iii, cahier 15, p. 248) appears to 
be incorrect. 


446 M. Carey Lea—WNotes on Silver Chlorides. 


ferricyanide and if the iron alum is in excess the whole of the 
silver is dissolved. It has been before noticed that the reac- 
tions between silver salts on the one hand and iron salts on the 
other are to some extent reversible, the observations just 
described place the matter in a somewhat clearer light. With 
a view of ascertaining whether ferrous sulphate could be com- 
pletely oxidized by argentic oxide a portion of the ferrous solu- 
tion was treated with successive portions of the oxide until the 
latter was no longer affected by it. But when this stage was 
reached the solution no longer contained a trace of iron, the 
whole of it had entered into combination with the silver. 
This combination is perfectly black and may probably have con- 
sisted of the compound described by H. Rose, as Ag,O, 2FeO 
Fe,O, and obtained in the same way. 

When ammonia iron alum is placed in contact with finely 
divided silver in considerable excess in a tightly closed vial 
the solution after a few days standing with frequent shaking 
acquires a deep red color. This may last for a week or more. 
The solution then decolorizes and becomes greenish but still 
contains abundance of ferric salt. Thusit appears that although 
silver has a powerful reducing action on ferric salts the action 
is self-limited and ceases long before complete reduction is 
effected for after many weeks contact in a closed vial there are 
abundant indications of the presence of ferric salt, although 
silver has been present in large excess. 


Arr. LVII.— Notes on Silver Chlorides ; by M. Carry LEa. 


EXPERIMENTS made by J. J. Acworth* at the suggestion of 
E. Wiedeman showed that by heating silver chloride to a tem- 
perature of 220° C. it passes into a modification that was 
insensitive to light. 

I think this ‘change may be due to the complete driving off 
of moisture. Abney showed by a well-known experiment that 
silver chloride when exposed perfectly dry in vacuo in a glass 
tube was totally unaffected by light, but I have shown that 
fused silver chloride poured into petroleum and placed in the 
sun-light without removing it from the liquid, was instantly 
darkened. 

These three experiments taken together lead to the following 
conclusions : 

1. Silver chloride dry and perfectly isolated is insensitive to 
light. (Abney’s experiment.) 


* Wied. Referate, 1890, p. 518. 


Keyes—Fauna at the base of the Burlington Limestone. 44% 


2. The presence of atmospheric air does not restore the 
sensitiveness, if the silver chloride has been absolutely dehy- 
drated at 220° C. (Aeworth’s experiment.) 

3. The presence of oxygen is not necessary or important for 
the darkening of silver chloride. The presence of moisture is 
not essential; its place may be taken by another substance 
capable of taking up chlorine. This follows from my experi- 
ment above mentioned. 

There is no doubt that silver chloride retains the last portion 
of water with great obstinacy. I have frequently tried to dry 
silver chloride in hot air so that it should lose nothing further 
by fusion, but never quite succeeded. There is always a loss 
which may be roughly taken at a half a milligram and from 
thence upwards to nearly one milligram, in a gram. When 
the water is thoroughly driven off it is probable that the sil- 
ver chloride is left in an insensitive condition. Acworth’s 
experiments seem to show this. 

So long as moisture is present the molecule of silver chloride 
easily breaks up, not merely by the action of lhght but by the 
application of any form of energy. The part played by 
moisture in chlorine reactions is somewhat remarkable. It has 
been lately stated that absolutely dry chlorine has no action 
upon copper foil. As soon as a trace of moisture is introduced, 
energetic action sets in. 


Art. LVIIIL—A remarkable Fauna at the Base of the Bur- 
lington Limestone in Northeastern Missouri ;* by CHARLES 
Rouiin KEYEs. 


In the description of a certain gasteropod (Porcellia nodosa 
Hall), in the third volume of the Illinois Geological Surveyt 
occurs the following paragraph, in connection with the 
assigned horizon and locality : ‘“ Lower Carboniferous ; Barry, 
Pike county, [llinois; from a. peculiar cherty, calcareous band 
at the base of the Burlington limestone, formerly supposed to 
belong to that rock, but now known to contain fossils charac- 
terizing the oolitic upper bed of the Kinderhook group, at 
Burlington, Lowa.” 

This allusion though merely incidental is the only direct 
one ever known to be made to the particular beds now under 
consideration. 

* Published by permission of Mr. Arthur Winslow, Director of the Geological 


Survey of Missouri, from work prosecuted during the years 1891-92. 
+ Geol. Surv. Illinois, vol. iii, p. 459. (1868). 


Am. Jour. Sc1.—THiRD SERIES, Vou. XLIV, No. 264.—DrEcEMBER, 1892. 
30 


448 CO. R. Keyes—Kauna at the Base of the 


At Louisiana, in Pike County, Missouri, which is separated 
from Pike County, Illinois, only by the Mississippi River, the 
‘““white chert” beds are much better developed than any 
where else in the region. It is from the Missouri locality that 
the recent collections have been made. Here the Burlington 
limestone is well exposed in the hilltops, where extensive 
quarries have been opened. 

For more than 70 miles, from above Quincy to below 
Louisiana, the Burlington limestone forms an almost contin- 
uous mural esear pment capping the high bluffs on either side 
of the Mississippi River. These bluffs rise to a height of 
from 300 to 400 feet above the water level. In many places 
they form bold, overhanging cliffs, with a heavy talus at the 
base. 

A vertical section of the rocks at Louisiana is as follows: 


Feet. 
16. Brown and white, compact, encrinital limestone, 
thinly bedded, with some chert ........------ 75 
15. White, encrinital limestone, very heavily bedded, 12 
14, Coarse- grained, encrinital limestone, with i irregu- 
lar chert bands @i000 S800 Vole ae 20 
13. Very heavily bedded, white encrinital limestone, 
with a peculiar white chert in nodules and 


irregular, bandsis22. aaa eee ae ae apt 

i2. Brown, encrinital limestone, compact and heavily 
bedded, somewhat earthy in places-_...-....- 15 

11. Compact, fine-grained, buff limestone, with few 
OF NO; PALtIN DS eee ar te ht a ee ee eee ae 15 

10. Sandy shales, brownish, forming soft, friable 
sandstoneslocallly, 252 see ave Ney eee 11% 
9) Greenish, clayey shales.os2) 4222.0 - 405 eee 70 


8. Thin-bedded, compact limestone, fine-grained, 
with conchoidal fracture, in layers 4 to 6 inches 
in thickness, like lithographic stone in texture 


and! Appearance 2 So ae le ae et nee 50 
Oegcatl diy? Clay sing le aussie Se up k Ly epaespey i aaeape eee 3 inches, 
6: Drab or greenish clayey, shales 222 35 3a eee 2 
5: Black, fissileiclay-shalems = = 52 sis ep ta eager 4 
4, Buff, magnesian limestone, very heavily bedded_ 10 
32 Compact) white oolite w= 222.5252 eee ee 5 
2. Blue clay-shale, with thin bands of impure lime- 

Stone rich in\fossils@aer 220.5! eee eeees eee 60 
1. Heavily bedded limestone, exposed ----_----.-- 5 


Number 1 is the Trenton limestone; 2 the Hudson River 
shales. 38and 4 probably represent the Niagara limestone; the 
first increasing rapidly in thickness southward and in a dis- 
tance of 20 miles reaches a vertical measurement of 30 to 40 


Burlington Limestone in Northeastern Missourr. 449 


feet. 5 and 6 are probably Devonian, equivalent to the 
“black shale” of adjoining States. Number 7 is a thin seam 
2 to 4 inches in thickness and highly fossiliferous. With few 
exceptions the ‘ Lithographic” fossils come from this layer. 
It probably belongs more properly with beds 5 to 6. Appar- 
ently the organic remains are nearly all identical with forms 
from the Hamilton rocks farther northward. Should the 
union of this thin, highly fossiliferous seam to the underlying 
shales be more in harmony with the real relation of the faunas 
of the respective beds, as now seems likely, than with the 
faunas above, it would remove to a great extent the present 
Devonian facies from the Lithographic (Louisiana) limestone. 
8 is the Louisiana limestone, a compact rather thinly bedded 
rock, breaking with a conchoidal fracture. It is very poor in 
fossils. Numbers 9 and 10 are the Hannibal shales. 11, the 
Chouteau limestone, with a few fossils. Number 12 is the 
Burlington limestone with the characteristic basal fauna of 
the Burlington. 13 is also the lower Burlington, carrying con- 
siderable chert and containing the most prolific fauna in the 
section. 14,15 and 16 belong to the Burlington limestone ; the 
upper portion containing the typical fauna distinctive of the 
upper division. 

From Quincy southward the strata rise very gradually, 
until the Burlington limestone, which appears a few yards 
above the ‘water level at that place, has an elevation of more 
than 250 feet above the river, at Louisiana. Below the lime- 
stone as will be seen from reference to the section, the beds 
are principally soft shales, which are eroded much faster than 
the great thickness of heavy, compact lime-rock overlying. 
High hills with precipitous slopes are formed. These are 
capped by the more indurated layers, rising in almost vertical 
walls from about midway up the elevations. In consequence 
of this, a peculiar and very striking phase of topography is 
produced, reminding one very forcibly of the topographical 
effects in a great driftless area of northeastern Iowa and the 
adjoining States. 

North of Quincy, as already stated, the Burlington rock 
dips below the water level of the Mississippi and does not 
appear again until just above Ft. Madison, in lowa, while at 
the city of Burlington the base of the limestone is nearly 100 
feet above low water-mark. At this place the organic remains 
have received more attention than anywhere else, while the 
vertical ranges of the different species have been determined 
with great accuracy. From this locality, also, the extensive 
faunas of the Kinderhook were first made known, and many 
species described. 

A third of a century has passed since the investigations of 
Hall, White, and Winchell brought to light so many interest- 


450 C. BR. Keyes—Fauna at the Base of the 


ing forms which characterize the beds immediately below the 
Burlington limestone. At Burlington, too, the Kinderhook 
and Burlington formations are sharply contrasted lithologically ; 
while faunally the two horizons are equally well defined. 

Passing southward one hundred miles, to Louisiana, Mis- 
souri, the same lithological and faunal features are found as at 
Burlington. These characters are shown for 50 miles along 
the great river in this vicinity. 

In the lower bed of the Burlington limestone (Number 12 
of the section) is found the typical. and well marked basal fauna 
of this formation. Many of the species, however, have a 
somewhat greater vertical range than at the Lowa localities. 

Among ‘the most characteristic species of ‘Crinoids to be 
mentioned are : 


Orophocrinus stelliformis (Owen & Shumard). 
Cryptoblastus melo (Owen & Shumard). 
Granatocrinus projectus (Meek & Worthen). 
Rhodocrinus Wachsmuthi Hall. 

Fhodocrinus Worthent Hall. 

Agaricocrinus brevis (Hall). 

Dorycrinus unicornis (Owen & Shumard).— 
Dorycrinus subaculeatus (Hall). 

Batocrinus aequalis Hall). 

Batocrinus longirostris (Hall). 

Batocrinus elegans (Hall). 

Actinocrinus proboscidialis Hall. 
Actinocrinus tenuisculptus McChesney. 
Physetocrinus ornatus (Hall). 

Steganocrinus sculptus (Hall). 

Steganocrinus araneolus Meek & Worthen. 
Platycrinus Americanus Owen & Shumard. 
Platycrinus Burlingtonensis Owen & Shumard. 
Platycrinus discoideus Owen & Shumard. 
Platycrinus subspinosus Hall. 


The fauna of this bed (about 15 feet in thickness) is pri- 
marily a crinoidal one. The above mentioned forms are some 
of the most important marking the limited horizon. Many 
other erinoids as well as brachiopods, corals, gasteropods, etc., 
are mingled; but they range upward into other layers more or 
less extensively. 

Above the basal bed is a slightly thicker member, of an 
intensely white color (number 138 of the section). It is chiefly 
encrinital like the other, but in addition contains a larger 
amount of comminuted shell material derived from mollusean 
remains, In places the shell fragments predominate, forming 
a fine shell breccia not unlike the well known coquina rock of 


Florida; but it is, however, so compact that good specimens 


oe bie” 


Burlington Limestone in NV ortheastern Missouri. 451 


of fossils are almost impossible to dislodge. The layers of this 
bed contain also considerable amounts of chert in small nodules 
and nodular bands. When first exposed in quarrying these 
cherts are very compact, translucent, and breaking with a con- 
choidal fracture. Upon exposure to the weather these flints 
quickly slacken like quick-lime to a fine intensely white powder. 
If examined before the process of disintegration has proceded 
more than half way the white nodules are found to be charged 
with fossils, which when taken out cannot be told from plaster- 
of-paris casts. Before affected by the atmospherie agencies, 
few or no traces of organic remains can be detected in the cherts. 
But they actually contain a very extensive assemblage of fos- 
sils; and in a perfect state of preservation when collected at 
the right time. They afford unusual opportunities for both 
structural and systematic studies; for many of the features 
commonly not met with are here found beautifully preserved ; 
such as the internal characters of crinoids and brachiopods, and 
the delicate ornamentation in nearly all groups. 

Upon careful comparison of the fossils in the eherts and in 
the surrounding limestones, so far as is possible in the latter, 
the fossils are found to be identical to a great extent. More- 
over, numerous shells and crinoids are found partly embedded 
in the chert and partly in the limestone, with a sharp line of 
separation, showing clearly that the siliceous impregnation had 
been acquired long after the original deposition of the beds, 
and was not due to a greater silicity of waters in which the 
calcareous deposits were made. This isin accordance with 
observations made elsewhere in the Burlington limestone of 
other localities. 

The faunal aspects of the bed in question (number 13 of the 
section) are particularly interesting. Some of the more com- 
mon as well as more important species are enumerated below ; 


Lingula melie Hall. 

Discina Newberryi Hall. 

Terebratula Rowleyt Worthen. 

Productus arcuatus Hall. 

Productus levicostus White.’ 

Productella Shumardiana (Hall). 
Rhynchonella Missouriensis Shumard. 
Spirifera peculiaris Shumard. 

Strophomena rhomboidalis var. 

Allorisma Hannibalensis Shumard. 

Edmondia nuptialis Winchell. 

EHdmondia Burlingtonensis White & Whitfield. 
Conochardium sp.? 

Lithophagus occidentalis (White & Whitfield.) 
Aviculopecten circulus Shumard. 


452 ©. R. Keyes—Fauna below the Burlington Limestone. 


Phanerotinus paradoxus Winchell. 
Capulus paralius (White & Whitfield). 
Capulus formosus (Keyes). 

Porcellia nodosus Hall. 

Loxonema pr olaag White & Whitfield. 
Loxonema sp.? 

Spherodoma penguis (Winchell). 
Pleurotomaria sp.? 

Holopea subconica Winchell. 

Murchisonia sp.? 

Bellerophon bilabiatus White & Whitfield. 
Straparollus ammon (White & Whitfield). 
Straparollus luxus ? (White). 
Omphalotrochus Springvallensis (W hite). 


The forms in the accompanying list are all species which 
characterize the Kinderhook of Burlington, Iowa; most of 
them being originally described from that place. In addition 
many more species of lamellibranchs, brachiopods and gastero- 
pods occurring very abundantly at the latter locality are found 
in the white chert of Louisiana along with afew of the Bur- 
lington limestone species. 

It is to be noted that: 

(1) The fauna of this horizon is predominantly molluscan, 
representing a marked contrast with that of the typical Bur- 
lington limestone, which is prevailingly crinoidal, with some 
brachiopodal forms. 

(2) The fauna is the typical one of the Kinderhook beds. 

(83) There is mingled with this fauna some of the forms 
from both above and below, which are thus associated with the 
species representing the typical lower Burlington limestone. 

Here, then, isa “well defined Kinderhook fauna intercalated 
in the Burlington limestone, with practically no change of 
lithological characters ; a lower fauna suddenly appearing in 
the midst of a higher. This is the most marked instance of 
the kind that is at present known in the Carboniferous of the 
Mississippi Valley. Though the time separation is not very 
great, the present case is a striking illustration of Barrande’s 
celebrated “doctrine of colonies,” so clearly developed in the 
Systeme Silurien du Centre de la Boheme,* and so ably de- 
fended in his “ Défense des Colonies.” 

It is not to be inferred, however, that during the short 
supremacy of the lower fauna in midst of an upper there was 
a complete extinction of the deposed forms; but rather that 
owing to peculiar conditions the lower fauna merely displaced 
the upper temporarily ; or pushed it aside into other districts 
for the time being. 


= Vols apy (358528) 


EH. W. Turner—Glacial Pot-holes in California. 453 


Art. LIX.—Glacial Pot-holes in Califorma,; by H. W. 
TuRNER, of the United States Geological Survey. 


In the eafion of the North Fork of the Mokelumne River, 
California, about thirty miles a little west of south from Lake 
Tahoe, and at an elevation above sea level of about 4,500 feet, 
is a group of pot-holes in the granite. The cafion here was 
formerly the bed of a glacier, as is evidenced by the polish and 
grooving of the rock and the perched bowlders. The rock 
about is quite devoid of soil. The pot-holes are from two to 
four feet in diameter and some of them are four feet deep. 
The shape of some of them is nearly conical, others more 
nearly cylindrical. Most of the pot-holes are eroded vertically, — 
but some of them are inclined. A number are quite shallow, 
but even these are broad and saucer-shaped. The granite 
flakes off in shells nearly parallel to its surface, and this would 
account for the broad form of the pot-holes at the commence- 
ment of their formation. 

The pot-holes are about 250 in number and from six inches 
to six feet apart. They seldom or never coalesce and the 
regularity of their arrangement is noticeable. The interior of 
all of the holes is well rounded and smooth, as pot-holes usually 
are. In some of them are rounded fragments of rocks; others 
are filled with sand and gravel. They cover a gently inclined 
surface of about two thousand square feet. To the north isa 
glaciated bank of granite, and the pot-holes occupy about the 
position that would be expected if formed by water falling 
over this bank. The height of the bank above the pot-holes 
is approximately forty feet. One pot-hole exists in the side of 
this bank several feet above its base. 

The river at the present time runs at a level of perhaps 
twenty or thirty feet below the lowest pot-holes. The place 
is locally known as Ham’s Salt Springs. Salt water oozes out 
from crevices in the rock and collects in several of the lower 
pot-holes. By evaporation, salt (NaCl) crystallizes out so that 
the water is usually covered with a thick layer of very pretty 
hopper-shaped crystals. 

The Indians are said to have formerly congregated here, 
attracted no doubt by the salt springs. Numerous small 
arrow-heads, chiefly of jasper and obsidian, were found by my 
party a little west of the pot-holes. At a point on the bare. 
granite below the pot-holes and very near the river are several 
small mortar holes such as are used by the Indians to grind up 
acorns, and which are frequently found in bare rocks in the 
Sierra Nevada. 


454 H. W. Turner—Glacial Pot-holes in California. 


At the time of my visit an old white man named Carlton 
was camped there with some Indians. He has been living 
with the Indians in the neighborhood of the Mokelumne River 
since 1851. He states that these pot-holes were made by the 
Indians for the purpose of collecting the salt water, in order 
to allow the salt to erystallize from it, On questioning him I 
could not make out that he himself had known of any such 
holes being excavated by the Indians. It would not, however, 
be a very difficult matter for the Indians to have made them. 
If a fire is built on the granite it flakes off very readily, and 
by repeating this operation for some time and using utensils 
in addition, cavities could be made. Mr. W. Q. Mason, of 
Voleano, California, who guided my party to the spot, believes 
the pot-holes to be the work of Indians. 

Plate IX represents a partial view of the pot-holes above 
described. The salt water at present oozes out at a point 
which may be located in the plate as about one-half inch from 
the middle of the left-hand side. It therefore runs only into 
some of the lower holes not represented in the picture. 

On a granite spur just south of the pot-holes and perhaps 
100 feet vertically above them is a little lake, partially filled 
with flags and tules. It has no outlet, but when the water 
is high “it can readily escape at its west end, The water is 
brackish. Some salt water must therefore have a higher 
source than that above indicated; and it is possible that salt 
water formerly flowed from crevices at points above the pot- 
holes and may have filled more of them than it does at present. 

The fact that few or none of the pot-holes coalesce perhaps 
favors the theory that they were made by the Indians, since in 
nature, pot-holes near one another frequently coalesce. The 
pot-hole, above described, in the side of the granite bank is 
evidently the work of falling water. It seems most likely that 
all the pot-holes were formed by the action of water, probably 
in some way connected with the glacier that formerly filled 
the cation. 

In this connection the reader is referred to an article oe 
T. T. Bouvé* who describes some glacial pot-holes near Cohas- 
set, Mass., and to Brégger and Reuscht who have studied 
those of Norway where pot-holes are numerous. 

It is interesting to note that in Norway they were at one 
time considered the work of the giants supposed once to in- 
habit that region, and that in America they are ascribed to the 
aboriginal Indians. 

Washington, D. C., September 5, 1892. 


* Indian pot-holes or giants’ kettles of foreign writers, Proc. Boston Soc. Nat. 
Hist., vol. xxiv, pp. 218-226. 
+ Giants’ kettles at Christiana, Quart. Jour. Geol. Soc., vol. xxx, pp. 750-771. 


H. W. Turner—Lavas of Mt. Ingalls, California. 455 


Art. LX.—TZhe Lavas of Mount Ingalls, California; by 
H. W. Turner, Washington, D. C 


[By permission of the Director of the U.S. Geological Survey. ] 


Mount INGALLS is situated just south of the fortieth parallel 
in Plumas county, California. It forms a portion of the 
eastern crest of the Sierra Nevada. Its elevation is 8,484 feet 
above sea level, according to the determinations of the topo- 
graphers of the U.S. Geological Survey. 

Mount Ingalls was a center of voleanic activity during much 
of later Tertiary time. The lavas which originated in its 
vicinity form an interesting series. The following rocks are 
represented : 

I. Late basalt, a rather coarse gray rock with much pyrox- 
ene and some olivine. It is usually massive. 

Il. Andesite, containing both pyroxene and hornblende, 
and occurring chiefly as a breccia. 

II. Older basalt, a dense black rock with little olivine, and 
a good deal of magnetite. It seems always massive. 

IV. Rhyolite, in very small amount. 

The order of succession is that .indicated by the Roman 
numerals with the exception of rhyolite ([V.) As has been 
previously noted* the rhyolite of the Sierra Nevada underlies 
the andesites, but its relation to the older basalt (ILD) is un- 
determined. The rocks may be roughly characterized as fol- 
lows: 

I. Late basalt.—This is macroscopically a coarse to medium 
grained light gray rock, sometimes pinkish, with large scattered 
olivines. Under the microscope it is seen to be nearly holocrys- 
talline and to be composed of lath-like plagioclase, augite and 
magnetite, with occasional large olivines. One of the slides 
shows a hypocrystalline glassy base containing abundant grains 
of magnetite, with numerous phenocrysts of plagioclase and aug- 
ite, and a few hypersthenes and olivines. In general, however, 
very little glass is to be seen. . 

The late basalt is the most recent of the lavas of this 
portion of the Sierra Nevada. It forms the summit and nearly 
all of the sides of Mount Ingalls down to and in places below 
the 7,000 foot contour. It rests, to a large extent, on andesitic 
breceia. Similar basalt caps a number of the higher points to 
the south and southwest of Mount Ingalls. Two of these are 
Mount Jackson and Penman Peak. There also the basalt rests 
on andesite ‘The later basalt is almost everywhere a massive 


* Mohawk Lake Beds, Bull. Wash. Phil. Soe., vol. xi, p. 389. 


456 HH. W. Turner—Lavas of Mt. Ingalls, California. 


rock, but a small amount of basalt-breccia and scoriaceous 
basalt forms two points on the summit of Mount Ingalls, per- 
haps remains of a former crater. In the ravine that heads just 
east of the summit of Mount Ingalls the basalt is glaciated. 
Its age, therefore, antedates that ‘of the glaciers of the Sierra 
Nevada. 

Il. Andesite.—This is chiefly a breccia. The anaalar frag- 
ments of andesite from this breccia are usually coarsely crys- 
talline and frequently vesicular. The color is dark gray, the 
feldspars showing as white spots. Frequently hornblende 
needles are macroscopically visible. 

Under the microscope the andesite is composed of pheno- 
erysts of plagioclase and pyroxene and of occasional horn- 
blendes in a groundmass sometimes very glassy, sometimes 
hypocrystalline with abundant plagioclase microlites and 
usually considerable magnetite. The pyroxene in some cases 
is largely augite; but there is frequently a good deal of hyper- 
sthene. Sometimes the rock is nearly holocrystalline. In some 
dark compact specimens of the andesite hypersthene is the 
most abundant bisilicate, but the prevailing type is the coarser 
one above described, and usually the predominant bisilicates 
are augite and hornblende. 

Andesitic breccia forms most of the ridge that extends 
southeasterly from Mount Ingalls. The same area continues 
to the north of Red Clover Valley. 

III. Older basalt.—This is a dense black rock usually show- 
ing macroscopically no porphyritic constituents except occa- 
sional olivines. It is frequently roughly columnar, the prisms 
being small, seldom more than three or four inches in diame- 
ter. The rock has been nowhere seen by the writer except in 
the massive form. 

Microscopically the rock is composed of lath-like plagioclase 
with more or less olivine and some augite in a groundmass 
which is rendered dark by the abundant magnetite. The 
groundmass sometimes contains considerable glass and _ fre- 
quently specks and minute prisms of augite. Much of the 
olivine is altered to serpentine. The plagioclases are usually 
small and of nearly even size. One slide, however, shows 
porphyritic plagioclases and olivines in a groundmass of plagi- 
oclase microlites, magnetite and glass. 

The older basalt forms an area of several square miles to 
the east of Mount Ingalls and west of Red Clover Valley. 
There is a smaller area at the southwest base of Mount Ingalls 
east of Little Grizzly Greek, and also another just southwest 
of the last and on the west side of Little Grizzly Creek. It is 
the lava of Walker Plains, in Plumas county, and of Moore- 
ville Ridge and Oroville Table Mountain, and the Iron Cation 


HT, W. Turner—Lavas of Mt. Ingalls, California. 457 


of Chico Creek in Butte county. So far as I am aware, this 
dense black older basalt is found only in Plumas and Butte 
counties. At numerous points it rests on Tertiary sediments, 
chiefly river gravels. It has nowhere been seen by the writer 
overlying or cutting through other Tertiary lavas. Its rela- 
tion to the andesite (II) is very evident about four miles east- 
southeast of Mount Ingalls on the ridge to the east of the 
road from Red Clover Valley to Genesee Valley. Here a 
nearly horizontal bluff of andesite above five hundred feet 
vertically above the road may be seen resting on the older 
basalt (III). A vertical section here would be approximately 
as follows: 

1. Andesitie breccia, thirty feet in thickness. This is made 
up of angular fragments of andesite cemented by volcanic ash. 
It shows no evidence of stratification. A little to the east of 
the bluff, lying on this breccia and presumably weathered 
from it, were found fragments of silicified wood. 

2. Fine even-grained andesitic tuff, one to four feet thick. 
The tuff layer is approximately horizontal. It is made up of 
minute fragments of plagioclase, augite, hypersthene, green 
hornblende, and apparently some quartz, with opaque and dis- 
colored particles. It is very plainly fragmental. It contains 
also fragments of plant stems. 

3. Andesitic conglomerate, fifteen feet thick. Immediately 
under the tuff and plainly resting on the older basalt is a vol- 
canic conglomerate containing some fragments of the older 
basalt as well as granite pebbles but chiefly made up of peb- 
bles and fragments of andesite. 

4. Older basalt, five hundred feet thick. This reaches from 
the bluff of the above fragmental materials 1, 2, and 3, down 
to Red Clover Creek below, a vertical distance of about five 
hundred feet. 

To the observer it is very manifest at this locality that the 
above series of volcanic fragmental rocks are of later date 
than the underlying basalt. The great thickness and extent _ 
of the basalt and the thinness of the overlying andesite ren- 
ders it extremely unlikely that it is an intruded sheet. More- 
over, the same superposition of the andesite on the older 
basalt may be noted at other points, as for example, at the 
southwest base of Mount Ingalls, at Iron Cafion in Butte 
county, and on the ridges to the north and south of Onion 
Valley Creek, in Plumas county. It is most probable that a 
period of erosion occurred between the time of the older basalt 
flows and that of the andesitic eruptions. 

IV. Phyolite—A small area of this rock was noted four 
miles to the southeast of Mount Ingalls, to the west of Red 
Clover Valley. The exposure is surrounded by andesitic 


458 HH. W. Turner—Lavas of Mt. Ingalls, California. 


breccia. Wherever in the Sierra Nevada its relation to the 
andesite is evident, it is the older rock. The relative age of 
the rhyolite and the older basalt has not been made out. I 
have nowhere seen them in juxtaposition. 

It is expected that the above rocks will be studied in more 
detail later, with the aid of chemical analyses, so that their 
exact position in the series of Tertiary lavas may be deter- 
mined. The subject is of especial interest in relation to 
Richthofen’s law of succession of volcanic rocks, to which 
this forms an apparent exception. 

The subject of the succession of the igneous rocks of the 
Great Basin has been considered in detail by Hague in the 
fortheoming monograph of the U.S. Geological Survey on 
the Eureka District, Nevada, and by Iddings* who states that 
igneous rocks of a mean composition are usually followed by 
both highly basic and highly acid types. 

The Tertiary lavas of Mount Ingalls rest on a base of much 
older rocks, schists, metamorphic tuffs and granite. The latter 
rock is of igneous origin, as 1s Shown by the inclusions in it of 
the older clastic rocks which are here in part at least, of Car- 
boniferous age. ‘These inclusions are numerous at a point on 
the southwest slope of the mountain, three miles from the 
- summit. 


Since writing the above, the following analyses have been 
obtained : 


Older basalt Late basalt 
(No. 276.) (No. 311.) 


SiO ES sare Nati 50°56 53°91 
DG ON se SBE UES Rae eal "52 
AN Oh See OA Pe eae Se Aca 17°95 
Ue O Peek Beetle Pate. 3°54 2°21 
ENS Ori. Syl nh tua Sey eee 8°90 4°80 
Mn@ gt = 2s SE seen ens alk 10 
CaO Baie Moree cue y 7°58 10°40 
SiO page eters! Gee gee trace ? trace 
BNO eee epee ee ence wae als ONS 05 
Mo Ost pede seme 4°07 5°52 
KO. 2) ee 2°10 1°34 
INS OM jee Weer ae 2°94 2-90 
TO) eh Fe eye ee trace ? trace 
BRON ENG OOH: Os ease 1:06 20 
EOvabovesO00iC see Tene 20 
PIOS OW een 114 21 

99°81 100°31 


*“The Origin of Igneous Rocks,” by J. P. Iddings, Bull. Phil. Soc. Wash- 
ington, vol. xii, pp. 89-214. 


P. E. Browning— Quantitative separation of Barium. 459 


The analyses were made by W. F. Hillebrand of the U. S. 
Geological Survey. It will be noted that the two basalts, so 
different in age and in habitus, are quite similar in composition. 
As would be expected in the dense black older basalt contain- 
ing a large amount of magnetite, the iron contents are much 
greater than in the coarse-grained gray basalt of later age. 

Washington, D. C., Sept. 9, 1892. 


Art. LXI.—A Method for the Quantitative Separation of 
Barium from Strontium by the action of Amyl Alcohol 
on the Bromides ; by Puinie E. BROWNING. 


_ [Contributions from the Kent Chemical Laboratory of Yale College—XIX.] 


THE existing methods upon which dependence can be made 
in the separation of barium from strontium are few in number. 
Dr. R. Fresenius in discussing them through several numbers 
of his journal* concludes that the only one which gives per- 
fectly reliable results consists of the precipitation of the 
barium by a double treatment with ammonium chromate in 
acetic acid solution. Having demonstrated the possibility of 
separating both barium and strontium from calcium by the 
dehydrating and appropriate solvent action of boiling amyl 
alcohol on the nitrates}.the possibility of a similar method of 
separation by the use of suitable salts of barium and strontium 
seemed worthy of investigation and necessary to complete the 
series as applied to this group. In looking about for suitable 
salts upon which to experiment the behavior of the chlorides 
was suggestive. Barium chloride is completely insoluble in 
amy! alcohol while the corresponding strontium salt is:some- 
what soluble. The possibility of finding strontium bromide 
more readily soluble than the corresponding chloride seemed 
worthy of attention. The method of preparation followed was 
the treatment of the precipitated and thoroughly washed car- 
bonates of barium and strontium with hydrobromic acid pre- 
paredt by mixing definite proportions of potassium bromide 
in solutions with sulphuric acid and water while hot, filtering 
off the potassium sulphate which separates on cooling, and re- 
distilling the filtrate until the distillate contains no appreci- 
able trace of sulphuric acid. The standards of the solutions of 
barium and strontium bromides made in this way were deter- 
mined by precipitating definite portions, measured and weighed, 
with sulphuric acid,—the strontium after the accepted method 
of adding ethyl alcohol to increase the insolubility and the 


* Zeitschrift fir Anal. Chem., xxix, 20, 143, 413. 
+ This Journal, xliii, 60, 314. { Proceedings Amer, Acad., xvii, 30. 


460 P. E. Browning— Quantitative separation of 


barium after the manner suggested by Dr. F. W. Mar,* pre- 
cipitating with an excess of sulphuric acid in the presence of 
hydrochloric acid. The mean of closely agreeing results was 
taken as the standard. Preliminary experiments on the 
bromides formed in this way gave encouraging results, the 
barium salt appearing to be almost completely insoluble while 
the strontium salt dissolved freely. The first series of ex- 
periments were directed toward a quantitative determination 
of the solubility of barium bromide in the alcohol. Definite 
portions of the standardized solution of barium bromide were 
measured from a burette into counterpoised beakers of about 
50 cm* capacity and weighed as a check on the burette reading. 
This solution was then evaporated to dryness, and the residue 
was dissolved in a few drops of water and boiled with 10 em* 
of amyl alcohol. The separating bromide was filtered off on 
an asbestos felt contained in a perforated platinum crucible, 
the whole having been previously ignited and weighed. The 
crucible containing the bromide was at first dried at 140°- 
150° C. in an air bath after the manner described in the 
previous papers, and weighed. ‘The unsuccessful attempt to 
get a constant weight, however, proved the impossibility of 
weighing as bromide, the weight decreasing rapidly with each 
successive drving. It was deemed best accordingly to dissolve 
the bromide from the felt into a beaker placed to receive it, 
and to precipitate with sulphuric acid in the presence of hydro- 
chloric acid, after the same manner followed in the determina- 
- tions of the standards. The precipitated sulphate, which in a 
few minutes settles completely, was filtered off upon the same 
felt from which the bromide had been dissolved, dried, ignited 
to low redness, and weighed. Series I gives the results of 
several experiments made after this manner which show the 
solubility of the barium salt to be about 0:0013 grm. on the 
oxide in 10 em.’ of amyl alcohol. The filtrate after boiling 
with amyl alcohol was evaporated and the residue was treated 
_with sulphuric acid and weighed; or the filtrate was precipi- 
tated directly by adding sulphuric acid, enough ethyl alcohol 
being added to secure thorough mixture. The amount of sul- 
phate found agreed uniformly with the loss determined in the 
residue after boiling. A portion of the salt which dissolved in 
the aleohol on being examined before the spectroscope gave 
only the green bands characteristic of barium. 


SERIES I. 
BaO taken. BaO found. Error. 
(1) 0°1234 grm. 0°1222 grm. 0°0012— grm. 
(2) O:0824 Tite 00809 < 0:0015 — 
(3) O-0823 <5 00809 “ 0:0014— 
(4) OsOSSie wks 0:0803 ‘ 0:0015— 
(5) O:ONis dics O:0720) 0:0013 — 


*This Journal, xli, 288. 


Barium from Strontium by Amyl Alcohol. 461 


Several methods of treatment were followed to prevent if 
possible this solubility, such as the addition of a few drops 
of hydrobromic acid before boiling, of the same after the 
barium bromide had separated, of a few drops of ethylene di- 
bromide or ethyl bromide at the completion of the boiling, 
of afew drops of bromine water before boiling, etc. The 
results of these experiments showed these modifications to be 
of little or no value. 

On boiling the strontium bromide with the aleohol slight 
spots separated occasionally, which on the addition of a drop 
of hydrobromic acid went into solution and did not appear on 
re-boiling. In order to determine the solubility of the stron- 
tium bromide in the alcohol a saturated solution was obtained 
by boiling an excess of the strontium salt with the alcohol, the 
salt in a measured portion of 10 cm* was precipitated as sul- 
phate by the addition of ethyl alcohol, and sulphuric acid, and 
weighed. Duplicate determination showed the solubility to 
be about 0-2 gram on the oxide in 10 cm* of the alcohol. The 
mode of procedure for the separation of these elements was 
identical with that already described in the case of barium alone 
up to the point at which the barium was filtered off, except, of 
course, the addition at first of a measured and weighed amount 
of a previously standardized solution, of strontium bromide. 
The strontium was precipitated from the filtrate as sulphate by 
dilute sulphuric acid, ethyl alcohol being added to secure 
thorough mixture. These precipitates were generally filtered 
off upon asbestos felts, and, although their gelatinous character 
delayed the filtration somewhat, the drying and burning of a 
filter paper with the possible danger of loss by reduction in 
the presence of burning paper was avoided. Series II gives 
the results of a single treatment, and it will be seen that there 
is apparently a slight contamination of the barium by the 
strontium which where the latter is present in large quantities 
balances the solubility of the barium (0-0013 grm. on the oxide.) 
Where the amounts of strontium taken are small the loss of 
barium due to solubility appears. 


Series II. 
BaO taken. BaO found. Error. SrO taken. SrO found. Error. 
orm. grm. grm. erm. erm. germ. 


MeO 22851 01225 0°0003 — 0°1070 0°1065 0°0005 — 
ZO ae O1231 0°0004 + 0°1074 - 071069 0:0005— 
3) 071224 0°1228 0°0004 + 0°1070 071067 0:0003— 
4) 0°1217 0°1201 0:0016— 0°0364 0°0372 0°0008 + 
5) 0°1216 0°1222 0°0006 + 0°0133 0°1124 0°0009— 
6) 00974 0°0970 0:0004— 0°0719 0°0721 0°0002 + 
7) 0:0971 0:0973 0°0002 + 0°0730 0°0727 0:0003 — 
(8) 0:0970 0:0971 0°0001 + 0°0718 0°0716 0°0002— 
(9) 0°0411 0°0390 8 0°0021— 0°0365 00385 0:0020+ 
(10) 0°0243 0'0234 0:0009— 0°1072 0°1072 0°:0000 


462 P. E. Browning— Quantitative separation of 


Series III gives the result of a double treatment. In this 
series the contaminating effect of the strontium salt disappears 
almost entirely leaving a deficiency of about 0:0025 grm. on 
the oxide to be added to the barium, and a corresponding 
amount of sulphate (0:0040 grm.) to be subtracted from the 
strontium sulphate before calculating it to the condition of 
the oxide. The manipulation is the same as that outlined for 
the single treatment, as far as the completion of the first boil- 
ing. At this point the amyl alcohol containing most of the 
strontium in solution was decanted upon a weighed and ignited 
felt and collected in a beaker placed to receive it. The residue 
of barium with traces of strontium was then dissolved in a 
few drops of water, a drop of hydrobromic acid was added 
and the boiling was repeated with another portion of 10 em* 
of amyl alcohol. Upon reaching the boiling poimt of the 
aleohol the beaker was removed, and the barium salt was fil- 
tered upon the felt through which the first portion had been 

decanted, and treated as before described. 


Series III. 
BaO found. SrO found. 

BaO taken. (Corrected.) Error. SrO taken. (Corrected.) Error. 

grm. grm. grm. grm, grm. grm. 
(GQ) ORan2 0°1219 0:0007 + 0°1068 0°1071 0°00038 + 
(2) eOgb2ie 0°1219 0°0004 + 0°0358 0°'0359 0:0001 + 
(3) 0°1220 0°1221 0-0001L+ 0°0353 0°0347 0°0006 — 
(4) 0:1212 071220 0°0008 + 0°0363 0°0358 0:0005 — 
(5) 071219 0°1221 0:0002+4 0°0361 0°0354 0:0007— 
(6) 01211 0°1218 0:0007+ 0°1126 0°1116 0:0010— 
CA) OS1TOL 0 -1SiL9 0°0000 0°0577 0°0586 0°0009 + 
(8) 0°0496 0'0492 0°0004— 0-0574 0°0579 0°0005 + 


The method is rapid, and while the correction to be applied 
owing to the solubility of the barium salt is. large it is so 
definite that it cannot be objectionable. The author in eoncelu- 
sion would express his indebtedness to Prof. F. A. Gooch of 
‘the Kent Laboratory for the many helpful suggestions re- 
ceived from him bearing upon this investigation. 


Art. LXII—A Wote on the method for the Quantitative 
Separation of Strontium from Calevum by the action of 
Amyl Alcohol on the Nitrates; by Puitip E. BRowNING. 


[Contributions from the Kent Chemical Laboratory of Yale College—XX.] 


RECENT work on my method for the quantitative separation 
of strontium from ealeium by the action of amyl alcohol on 


Barium from Strontium by Amyl Alcohol. 463 


the nitrates* has demonstrated the possibility of using very 
much smaller amounts of amyl alcohol in the boiling than the 
amounts formerly used (80 cm’ for each treatment). By the 
use of smaller beakers (50 cm* capacity) 10 em* of the 
aleohol can be conveniently substituted for 30 cm’, and the 
correction for solubility of the strontium nitrate is thus 
reduced from 0-001 grm. on the oxide to 0:0003 grm. in each 
treatment, and the corresponding amount of sulphate to be 
substracted from the calcium sulphate before calculating to the 
condition of oxide is reduced from 0:0017 grm. to 0:0005 grm. 
in each treatment. The necessity of a double treatment, or 
the use of two portions of 10 cm* each of the alcohol, brings 
the total correction to 0:0006 grm. on the strontium oxide, and 
00010 on the calcium as sulphate. For ordinary work such a 
correction may be disregarded. The following tables give the 
corrected and uncorrected results. 


TABLE I (correction disregarded). 


SrO taken. SrO found. Error. CaO taken. CaO found. Error. 

erm. grm. grm. erm, grm. erm. 
(1) 0°0570 0°0565 0:0005 — 0°05384 0°0540 0°0006 + 
(2) 0°0573 0°0567 0-0006 — 0'0534 0°0543 0°0009 + 
(3) 0°0285 0°0274 0:0011— 00272 0:0276 0°0004 + 
(4) 0°0568 0°0560 0:0008— 0°0535 0°0537 0°0002 + 
(5) 0°0568 0°0561 0°:0007— 0:0538 0°0535 0'0002 + 
(6) 0°0288 0°0280 0:0008 — 0:0271 0:0272 0°0001+ 
(7) 0:1420 0°1416 0°0004 — 0°0535 0°0544 0°0009 + 
(8) 0°1419 0°1416 0:0003 — 0:0665 0:0669 0°0004 + 
(9) 071135 0°1132 0:0008 — 0'1066 0°1070 0°0004 + 
(10) 0°1137 0°1126 0-001L1— 0°1064 0°1070 0:0006 + 

TABLE II (correction applied). 
SrO found, CaO found. 

SrO taken. (Corrected.)  Hrror. CaO taken. (Corrected.) Error. 

erm. erm. grm. erm. grm. grm. 
(1) 0°0570 0°0571 0:0001 + 0°0534 0°0536 0°0002 + 
(2) 0°0573 0°0573 0:0000 0°0534 0°0539 0:0005 + 

(3) 0°0285 0°0280 0:0005 — 0:0272 0°0272 0:0000 
(4) 0°0568 0:0566 0°0002— 0°0585 0°0533 0:0002 — 
(5) 0:0568 0°0567 0:0001 — 0°0538 00531. 0°0002— 
(6) 0°0288 0°0286 0:0002 — 0:0271 0°0268 0:0003 — 


(7) 0°1420 071422 0:0002+ 0:0585  0:0540 0:0005+ 
(8S) 071419 0°1422 0:0003+ 0:0665  0:0665  0:0000 
(9) 071135 071188 0:0003+ 0°1066 0:1066  0:0000 
(10) 071137 G:1132 0:0005— 0:1064 0:1066 0:0002+4 


* This Journal, xliii, 50. 


Am. Jour. Sct.—THIRD Series, Vou. XLIV, No. 264.—DrcremBER, 1892. 
31 


464 W. P. Headden— Formation of the Alloys of 


Art. LXIIL—A Study of the Formation of the Alloys of 
Tin and [ron with descriptions of some new Alloys ;* by 
WitiiamM P. HEADDEN. 


Axsout three years ago I had occasion to investigate some 
tin buttons obtained in assaying tin ore by the potassic cyanide 
method, and observed that the alloy obtaimed by oxidizing the 
buttons with hydric nitrate and treating the oxidized mass 
with potassic hydrate was not only significant in quantity, 
ranging from one and a half to ten and a half per cent, but 
varied in form also, though obtained under similar conditions 
of charge and temperature. Subsequent investigations con- 
vinced me that the same is true of dross obtained by meltin 
larger quantities of tin ore with anthracite dust, lime aa 
fluor spar in a graphite pot. As the latter method yields 
larger quantities at less expense, the dross from such fusions 
was used, as a rule, in my investigations. 

Of the buttons first investigated, the first yielded about 
7 per cent of a non-magnetic alloy corresponding to the for- 
mula Fe,Sn,; the second yielded a quantity of magnetic 
alloy corresponding to the formula Fe,Sn,; while the third 
yielded a non-magnetic alloy, so small in quantity, however, 
that no analysis was attempted, but its form differed from that 
of the other two, and I had no reason for believing it to be 
identical with either of them. Its form was that of a six 
sided prism with etched and pitted basal plane which was 
seldom perfect though always present. This was probably 
an imitative form after an orthorhombic combination. 

The results of the investigation to which this led may be 
briefly given as follows: i. e. “that there is a series of stannides 
of iron “of which I obtained the following members, FeSn,, 
Fe,Sn,, Fe,Sn,, Fe,Sn,, Fe,Sn, and FeSn—and in addition to 
these, the following, Fe,Sn, F e,Sn and Fe,Sn. 

Some of these have been described before, but the deserip- 
tions given by the various investigators agree in assigning 
them properties, some of which differ widely from those 
observed in my alloys. Those previously described are FeSn,, 
Noellner; FeSn, Deville and Caron; Fe,Sn, Lassaigne, and 
Fe,Sn, Bergman. The first of these "has more recently been 
studied by A. C. Oudemann, Jr. Noellner says that FeSn, is 
insoluble in hydric chloride. While Oudemann makes no 
definite statement on this point, merely stating that he prefers 
to use hydric nitrate in separating it from the excessive tin 
leaving it to be inferred that he found it at least difficultly 


* Abstract of article read before Colo, Scientific Society—Address of retiring 
President for 1891. 


Tin and Iron with descriptions of some new Alloys. 465 


soluble in the hydric salt. Deville and Caron describe FeSn 
as insoluble in hydric chloride and crystallizing in plates. 
The alloys which I have obtained, giving these formulas, do 
not agree with these descriptions. All writers on these alloys 
agree in giving aqua regia as the solvent for them. I have 
uniformly used hydric chloride and have found but a small 
amount of any one of them insoluble in this agent, and the 
portion insoluble in it was almost as insoluble in aqua regia. 
The description of forms is also quite at variance. This may 
be due to difference of interpretation of the forms, or it may 
indicate that these alloys vary greatly, both in form and prop- 
erties according to the conditions under which they are formed ; 
my observations tend to establish the latter. The compounds 
Fe,Sn,, Fe,Sn,. and Fe,Sn, vary in their property of being 
magnetic, sometimes being almost or quite non-magnetic, and 
it will require a more exhaustive study of their crystal form 
to establish any distinctive difference between them in this 
respect; the habit of the crystals as obtained is, it is true, 
somewhat different, but it is doubtful whether it is uniform 
and persistent enough to be relied upon as distinctive. I have 
recognized but one form with certainty, a rhombic prism, 
which is the crystal form of the alloy FeSn,. Though some 
erystals of this form were observed which have not been 
proven to be this alloy and this form may be common to 
several alloys. Furthermore certain rough six-sided imita- 
tive forms have been observed, which are not characteristic 
of any one of at least three alloys These facts indicate as 
already suggested, that the various observations may not be 
contradictory because made on material which is not perfectly 
comparable. 

The members of this series are all brittle, so-much so 
that in the form in which they were obtained, they can 
be rubbed to a powder between the thumb and finger ; 
they all burn, readily and quite brilliantly, when strewn into 
the flame of a candle or alcohol lamp with the formation of a 
dense smoke, and the emission of an intense odor of tin, best 
observed a short distance above the flame. This odor was so 
intense and similar to that of arsenic that it was with difficulty, 
and only after repeated experiments, that I convinced myself 
of the absence of this element. 

These alloys require so high a temperature to fuse them that 
I was able to fuse only small portions of them before the 
blowpipe, and that not very satisfactorily ; whether they suf- 
fered decomposition thereby was not evident, but with soda 
on charcoal they were decomposed with emission of sparks and 
the separation of malleable tin. Concentrated hydric sulphate 
acts upon them violently with copious evolution of sulphur 
dioxide. 


466 W. P. Headden—Formation of the Alloys of 


That iron and tin readily unite with one another is well 
known, but the character of the iron and the temperature are 
important factors. When reduced iron was used the combina- 
tion ensued quickly and the solution of the iron in the tin was 
perfect, but when cast iron was used this was not the case ; 
but the presence of the carbon did not prevent the formation 
of these alloys. 

Whether these alloys can endure remelting without decom- 
position or not was not decisively proven, but the experiments 
made tend to show that they can be melted by themselves and 
kept at a temperature sufficient to melt cast iron for an hour 
without perceptible decomposition, and if melted with tin 
already saturated with the alloy they may be remelted several 
times without material change, at least within the limits of 
temperature under which my experiments were made. While 
it is evident from my experiments that the frequent remelt- 
ings to which the reguluses were subjected had at most only a 
very subordinate influence in determining the alloy formed, 
it is equally evident that the influence of the ratio of tin to 
iron is very great; it appearing to be the determinative con- 
dition in the formation of the series from FeSn to FeSn,, but 
for the alloys Fe,Sn, Fe,Sn and Fe,Sn it would seem that we 
will have to look for some other condition as the ratio of iron 
to tin alone will evidently not suffice in explaining their for- 
mation. 

It is probable that the alloy first formed during the reduc- 
tion is not that with the highest ratio for the tin, as is indi- 
cated by the results of the investigation of the buttons from 
the cyanid assay which had not been remelted and some of 
them had been in the fire but eight minutes and still yielded 
the intermediate members of the series which according to 
our observations are formed between wide limits in the ratio 
of tin to iron, and this too when the atomic ratios of the iron 
to tin in the buttons was such as to justify the expectation of 
finding an alloy having a higher tin ratio. It is difficult to 
say in which experiment we approached most nearly to the 
conditions existing in the original mass of tin but probably in 
the first in which the regulus resembled pure tin but yielded 
an alloy having the ratio (Fe: Sn) 1:1; in another in which 
case the fusion was effected at a higher temperature and con- 
tinued longer the alloy had the ratio of 1: 1°25; but in this 
case we had a small amount of a very rich iron alloy with the 
approximate ratio of 9:1 separated from the regulus which 
might have had some influence upon the ratio of the alloy, 
especially if this iron alloy is a product of the decomposition 
of alloys richer in tin which already existed in the mass 
which, however, I hold to be doubtful. In still another the 
alloy obtained had the ratio of 1:1 and there was a large por- 


Zin and Iron with descriptions of some new Alloys. 467 


tion of iron alloy or bottom with the ratio 4: 1 and in a fourth 
one the alloy had the ratio of 1:1 though the bottom 
amounted to over 33 per cent of the weight of the regulus. 
An examination of the ratios of the alloys yielded by the 
different reguluses shows that the presence of an iron bottom 
does not necessitate the lowest ratios for the tin; for in such 
cases we have the ratios 100, 1:20, 1:25, 1°33, and 1-5 nor does 
its absence indicate the highest ratios; for in such cases we 
have the same ratios as before,—still, in a general way, those 
reguluses having an iron bottom yield alloys with lower ratios 
than those which have none, but the difference is neither de- 
cided enough, nor sufficiently constant to justify the conclu- 
sion that they are end-products of a series of decompositions, 
with successive eliminations of tin and consequent enrichment 
of iron in the alloy. The ratio of the alloy depends upon the 
ratio of the iron to the tin in the mass rather than upon any 
possible decomposition. 

Some experiments were made with the object of buildin 
up the series from the lowest to the highest ratio with the 
following results. A quantity of dross containing the alloy 
FeSn was fused with one and a fourth times its weight of 
bar tin and the principal portion of the resulting alloy had 
the ratio of 1:25 but further changes also took place as indi- 
cated by such ratios as 1°33 and 1°66 obtained for smaller por- 
tions of alloys. When the atomic ratio of the iron to tin in 
the mixture was made as 1:6 the ratio of the alloy was 
changed from 1:1 to 1: 1°38 and the same result was obtained 
when the tin in the mixture was increased so that the atomic 
ratio of the Fe:Sn was as 1:18. When I used the alloy 
Fe,Sn, and the atomic ratio of the mixture was made 1 : 25, 
the ratio of the alloy was changed from 1: 1:25 to 1:1°33; 
the same result was obtained by using the alloy FeSn and 
making the atomic ratio of the mixture 1: 41,1. e. the ratio 
of the alloy was raised from 1:1 to 1: 1°33; using the same 
alloy and making the ratio of the mixture 1:98 a mixed 
result was obtained the ratio was raised in part to 1:25 but 
principally to 2 but when the atomic ratio of the mixture was 
made 1: 124 the ratio of the alloy, insoluble in hydric nitrate 
always understood was raised from 1:1 to 1:2. Equally 
satisfactory results were obtained when I used reduced iron 
“Ferrum reductum,”’ instead of the alloys so long as I ob- 
served the ratios in the mixture, showing that the use of the 
alloy had no influence upon the result of the reaction. 

It is evident that the ratio of Fe:Sn in the mixture has a 
determining influence upon the resulting alloy, also that the 
limits of this ratio for some of the alloys is quite wide espe- 
cially for the alloys Fe,Sn, and Fe,Sn, but it seems that the 
formation of others is confined to narrow limits or peculiar 


468 W. P. Headden—Formation of the Alloys, e’e. 


conditions as Fe,Sn, which was found to be the chief alloy in 
only one instance, i. e.. where the atomic ratio of the mixture 
was 1:22 and this is singular; for in other instances where 
the ratio was 1: 25 and 1:41 respectively an alloy with a lower 
ratio, 1. e. 1°33 was obtained and, moreover, 1 : 22 is the ratio 
given in Watts’s Chemical Dictionary for a definite alloy. The 
regulus from which I obtained this alloy and having this ratio 
could not in any sense be considered an individual alloy. 

I have not intended to even intimate that the whole of the 
iron in the reguluses obtained existed in the form of alloys 
difficultly or insoluble in hydric nitrate; for at least one alloy 
soluble in this agent and crystallizing in long and wide but 
thin plates was observed. 

The temperature, duration of fusion, and rate of cooling are 
very subordinate in their influence upon the alloys formed 
both in regard to their properties and their distribution through 
the regulus. 

The only alloy whose form could be definitely made out 
was the alloy FeSn, which crystallizes in bright shining rhom- 
bie prisms, being combinations of 001, 110, 010, from brownish 
black to black in color with metallic luster. 

Another form is a six-sided often furrowed, almost always, if 
not always hollow form. This form is very interesting but 
not characteristic as 1t is common to several compounds. 

The terms iron alloy and iron bottom have been used to 
designate a hard, gray and strongly magnetic mass forming 
the lower part of some of the reguluses and amounting in one 
case to rather more than one-third of the same by weight. 
My analyses of these contain two errors which being in oppo- 
site directions about neutralize each other, ouly one of them, 
however, affects the ratio of the iron to tin when these are ealcu- 
lated to one hundred, i. e. the carbon which seriously impairs 
the value of the ratios obtained and it is no matter for surprise 
that only one of the analyses gives even an approximate ratio; 
the fact that the material analyzed had to be used just as it 
was taken from the crucible may account for this in part but 
it is a question whether these bottoms are other than gray cast 
iron alloyed with or containing varying quantities of tin. 
My experiments seem to prove that their formation does not 
depend upon the presence of a large quantity of iron, i. e. that 
they are not products of dissociation, but that the presence of 
carbon is absolutely necessary to their formation. 

These compounds, which I have classed with the tin com- 
pounds despite this degree of uncertainty as to their true 
nature, demand our attention and awaken our interest even if 
they are related to cast iron, for they have been found to col- 
lect other compounds still to be described. 

State School of Mines, Rapid City, S. D. 


C. D. Walcott—Cambrian Rocks of Pennsylvania. 469 


Art. LXIV.—Wotes on the Cambrian Rocks of Pennsylvania 
and Maryland, from the Susquehanna to the Potomac; by 
CHARLES D. Watcorv. 


[Read before the Philosophical Society of Washington, Oct. 29, 1892. ] 


THE special study of the Cambrian rocks of the Southern 
Appalachians* was limited during the past field season to 
an examination of some of the more important exposures of 
the group in central Pennsylvania and Maryland. Within 
this area between the Susquehanna and the Potomac rivers 
two points have been the subject of investigation by geolo- 
gists, and decided differences of opinion exist in regard to 
the stratigraphy and the geological age of the rocks embraced 
within them. One is that of South Mountain as it occurs in 
Franklin, Cumberland, York and Adams counties, in Penn- 
sylvania. The second is the area about Harper’s Ferry, 
.Virginia. After an examination of the published literature, 
including geological sections and maps, it was decided to begin 
work in York county on the Susquehanna and to extend it 
southwest to the Potomac. Prior to this three days were 
spent at Mount Holly Springs, in the northwestern part of 
South Mountain, in a preliminary examination of the quartz- 
ites exposed at that point. The discovery of the lower 
Cambrian or Olenellus fauna in a synelinal trough near the 
western foot of the mountain, gave an important datum point 
which was afterwards of great service in work to the south in 
Franklin county. 


York County. 

Dr. Persifor Frazer considers the Lancaster limestones as 
probably the equivalent of the Calciferous and Trenton lime- 
stones of the New York series, and mentions that the York 
limestone is a slender offshoot.t The Hellam quartzite of 
York is called the ‘‘Chikis” quartzite, and is described as a 
basal formation upon which a series of schists occur that to 
the south “are, at all events, those slates in which the iron 
ores of Lancaster and York are invariably found, the transition 
series between the Primal and Auroral.”{ Professor Lesley 
deseribes in his final report$ the ‘“‘Chiques” sandstone as the 
same formation as the Hellam quartzite of York county (as 

* Notes on the Cambrian rocks of Virginia and the Southern Appalachians, 
this Journal, vol. xliv, 1892, pp. 52-57. 

+ 2d Geol. Survey of Penn. Report of Progress in 1877. Geology of Lan- 
caster County, 1880, p. 4. t Loe. cit., p. 7. 


§ Geol. Survey of Penn. Summary Description of the Geology of Penn, vol. i, 
1892, p. 165. 


470 C. D. Waleott— Cambrian Rocks of Pennsylvania. 


named by Frazer) and equivalent to the upper Cambrian 
quartzite of Walcott. He prefers to use the older name 
‘“Chiques” for these sandstones, stating that it is best to get 
rid of the old name ‘‘ Potsdam” sandstone, as there does not 
seem to be any satisfactory evidence that the proper Potsdam 
sandstones of the Canada line and Lake Champlain extended 
as far south as southern Pennsylvania. He says that the sec- 
tion at ““Chiques Rock” is not quite comprehensible at one or 
two points. I found that it was so complicated by thrust 
faulting that it is not a typical section. It exposes, however, 
the lowest of the Cambrian rocks now known to me in central 
Pennsylvania. The ‘“ Chiques Rock” proper, near Chiques, is 
the Scolithus quartzite, and is in an unbroken section at the 
summit of the series of the quartzites and slates of the Chiques 
section although now apparently at the base of the section. 
The quartzites to the south, between “ Chiques Rock” and the 
limestones at Columbia, are older and have been raised up 
from beneath and thrust over on the Scolithus quartzite at 
“ Chiques Rock.” This is determined by the succession shown* 
in the section exposed on the flanks of South Mountain, in 
Franklin county west of Monterey, reference to which is made 
in the notes on the geology of South Mountain. In relation to 
the stratigraphic position of the slates, ete., beneath the Lan- 
easter limestone, I will quote the statement of Professor 
Lesley, “The geographical proof that the slates overlze the 
quartzite is complete; and establishes the correctness of Pro- 
fessor Rogers’ Upper Primal slate formation. The geological 
evidence is equally conclusive; for the general dip in the 
Chiques rock is southward, under the slates; and of the slates. 
southward under the limestone.’”’* 

The continuation of “Chiques Rock” to the westward, in 
York county, forms the Hellam hills+ and shows a broad anti- 
clinal of quartzite surrounded by schists. Numerous sections 
along the southern and western sides of the Hellam hills show 
that the quartzites pass beneath a series of shales, slates, sandy 
and calcareous layers that, in turn, pass beneath the limestones 
of the valley. 

It was my good fortune to have the acquaintance of 
Prof. A. Wanner, superintendent of public schools at York. 
He volunteered to be my guide to localities where there 
were good exposures of the quartzites, schists and limestones, 
and he gave me valuable assistance. A reconnaissance was 
first made of the section at “ Chiques Rock” south to Colum- 


SOC Citas slater 

+ 1 did not learn of any local name for this ridge of hills when in York county, 
and as most of the ridge is within the township of Hellam I shall speak of them 
as the Hellam hills. 


CO. D. Walcott—Cambrian Rocks of Pennsylvania. 471 


bia, and then on the western side of the river from Wrightsville 
north to the quartzites. On the western side of the river the 
section appeared to be unbroken from the Hellam hills to 
Wrightsville, and to be as represented by Dr. Frazer* in his 
section along the right bank of the Susquehanna. In this the 
suecession is from a quartzite (1) to shales (2) and to limestone 
(8), the latter in Wrightsville, at the Columbia bridge; the 
sandy shales and argillites (2) pass conformably beneath the 
massive limestone (8) which forms a deep synclinal fold before 
being cut off to the south by a fault. 

The second section examined was No. 2 of Dr. Frazer’s, 
extending from Emigsville south through Red Lyon station.t 
In the description of this section { he refers the sandstone in 
the railroad cut just north of Emigsville to the Tridssic New 
Red sandstone. At the northern end of the cut he noted a 
fine-grained sandstone, dipping 15° west, north 52 degrees. 
To the southward of this he describes a calcareous, sandy, pink 
shale, dipping south 5°, east 20°. This is subjacent to 27 feet 
of blue, finely laminated limestone, with white streaks, upon 
which rests a red bed of calcareous conglomerate two feet thick : 
this in turn is subjacent to a belt of reddish shaly sandstone, 
nine feet in thickness, which is capped by 156 feet of arena- 
ceous shales of a somewhat flaggy character. 

He says: ‘‘ There would seem to be, therefore, an anticlinal 
in the Triassic measures—the only instance of one recorded 
within the limits of this district. ‘The contact line of lime- 
stone and Mesozoic sandstone lies within or just north of the 
town of Emigsville. The first recorded dip in the older for- 
mation when projected upon the line of section is 2,160 feet, 
or a little more than a third of a mile from the last dip.”§ I 
mention the details of Dr. Frazer’s section as it is the one 
which led me to the determination of the stratigraphic position 
in the geologic series of the Chiques quartzites and the York 
shales | which are subjacent to the Lancaster limestone.4) 
The fault betweeen the Paleozoic (Lower Cambrian) rocks and 
the New Red sandstone of the Mesozoic occurs in the railroad 
cut, at the point indicated in Dr. Frazer’s section as the crest 


*Second Geol. Survey of Penn.. 1876. Section 1, accompanying Report of 
Progress in the district of York and Adams counties for 1874. 

+ Loe. cit., Section 2. t Loe. cit., p. 88. § Loe. cit., p. 89. 

|| The name York shale is proposed for the band of shales resting upon the 
quartzites surrounding the Hellam hills. It is pecuharly well developed in York 
county, and appears to be absent in many of the sections about South Mountain 
and about the same series of quartzites in Lancaster county. 

“| The term York limestone was proposed by Dr. Frazer for this limestone; but 
as he states that it is a prolongation of the Lancaster limestone into York county, 
and that it is more fully developed in Lancaster county, I think it best to retain 
the term Lancaster limestone, as it is hardly necessary to call the same limestone 
by two different names in adjoining counties. 


472 ©. D. Walcott—Cambrian Rocks of Pennsylvania. 


of the anticlinal in the New Red sandstone. No such anti- 
clinal exists. The southern leg of Dr. Frazer’s anticlinal is 
formed of rocks that bear no resemblance to the Mesozoic Red 
sandstone, and fossils of lower Cambrian age are abundant in 
_the nine feet of compact, fine grained sandstone described by 
him. The section, from the fault line southward, is as follows: 


Thickness. 


Feet, 
1. Gray, banded and mottled limestones, with purplish bed 
of limestone at summit three feet thick. This limestone 
weathers into a more or less arenaceous shale. 
Strike. Hic W..(Maes) (Dip) 255 \Si a. ea eee ae 33 
2. Gray and buff sandy shales passing (at 21 feet) into shaly 
sandstone and then into sandy shale, where a belt of 
calcareous quartzite occurs in layers varying in thickness 
from, 2:to 12) taches ope pao oo le eo pee 105 
Fossils :—Camerella minor, and fragments of Olenel- 
lus, showing portions of the head and thoracic segments.* 
3. From the fossiliferous beds just mentioned, for a distance 
of 500 feet the hillside on the east of the railroad is 
covered with the debris of sandy shales, and several ex- 
posures occur along the wagon road. From the last of 
these to the first outcrop of limestone, a distance of 250 
feet, the debris of sandy shales and thin-bedded calcare- 
ous quartzite occur abundantly in the southward-facing 
hillslope. As the last observed dip was 25° S., it is 
assumed that the section is unbroken, and a thickness is 
assigned to this division Of-= 4.2 02-2 2) 2 3 Seen ee 
Fossils :—Numerous fragments of Olenellus and casts 
of Camerella minor occur in the calcareous quartzite 
interbedded in the shale. 
4, Massive-bedded, dove colored, banded limestones. Strike 
N. 20° W. (Mag.) Dip, 25° 8.} near base of series. _Al- 
though the section is more or less concealed by soil, 
numerous outcrops occur in quarries to the south. These 
show a banded limestone in the lower portion of the sec- 
tion with numerous irregular, small, concretionary bits 
of limestone, usually elongated with the bedding plane. 
The average dip of the beds is from 20° to 25°S. A 
beautiful section is shown in a quarry about one-fourth 
of a mile east of Emigsville, and in a quarry on the 
turnpike west of the railroad in the outskirts of the 
town. A little higher up in the section the limestones 
are massive, light colored, and, in places, almost a white 
crystalline marble. 


* On the line of strike of these beds, two niles northwest of Emigsville, the 
following fauna was found in the caleareous sandstones: Camerella minor, Obo- 
lella crassa, Hyolithes communis, and fragments of Olenellus. 

+ Dr. Frazer’s section indicates a dip of 85°. 1 was not able to discover the 
locality where he observed it. 


> “G,, > ott aad sy 


At 


C. D. Waleott— Cambrian Rocks of Pendsvanin 473 


At a quarry in a field east of the railroad track and 
near where the roadway turns to the eastward towards 
Codorus creek, the strike of the limestone is N. 15° 
(Mag.), and dip 15° S. One of the layers is quite fos- 
siliferous and gave fine specimens of a species of Salte- 
rella and Kutorgina, heads of small trilobites of the 
genera Solenopleura and Zacanthoides, and numerous 
fragments of the head and thoracic segments of a 
species of Olenellus. 

Further to the westward in an old quarry east of the 
Northern Central R. R. track, massive layers of lime- 
stone are shown that have a strike N. 20° W. (Mag.) ; 
dip 208., and contain fragments of the genus Olenellus 
and Protypus. The next higher exposure in the section 
is in a large and deep quarry just west of the R. R. 
track, between one-fourth and one-half mile south of 
Emigsville. About 60 feet of limestone is exposed. 
The strike is E. and W. (Mag.), with a dip of 10° to 
the south. In the lower portion of the quarry there are 
massive layers of arenaceous limestone, and about ten 
feet from the summit of the section, alternating bands of 
earthy and pure limestone in which numerous fossils 
occur. In the collection obtained I have recognized : 

Plates of Cystids. 

Kutorgina, n. sp. 

Orthisina festinata Billings. 

Olenelius (fragments). 

Protypus senectus Billings. 

The fragments of Olenellus indicate individuals as large 
as any known. The fossils range through about twenty 
to twenty-five feet of the limestone. The layers above 
the fossiliferous band are largely brecciated and form a 
limestone conglomerate. The estimated thickness of the 
entirerseriesiol limestone: spe) ua rset Lo eens a ap 750 

In the railroad cut the limestone is shown, and, a little 
to the south of them, cleaved slates the bedding of 
which strikes east and west (Mag.) and dips 10° south. 
There is an interval of 20 feet between the limestone 
and slates covered by debris. The limestone appears to 
pass beneath the slates, and from the areal distribution 
of the slates and limestone to the south and southwest 
it is probable that this upper band of slates has a wide 
distribution ; its thickness is unknown. 


An area of quartzite, No. 2 of section, is colored on the map 
two miles N. W. of Emigsville as of the same age as the 
Hellam quartzite. It is, as we now know, a thinner belt of 
quartzite resting in the calcareous and sandy shales above the 
quartzite of the Hellam hills) The next point determined 
was the actual relation of the Olenellus quartzite at Emigs- 


474 ©. D. Waleott—Cambrian Rocks of Pennsylvania. 


ville with the massive Scolithus quartzite of the Hellam hills. 
In passing from Pleasureville towards York, on the steep side 
hill two miles west of York there are exposures in the road- 
side of shales and calcareous sandstone above the massive 
quartzite of the Hellam hills. At a point probably 100 feet 
beneath the ferriferous shaie in which the numerous‘ore pits 
occur on the south side of the Hellam hills, a species of 
Obolella, very closely allied to Obolella crassa, and fragments 
of Olenellus were found in the decomposed calcareous sand- 
stone. Ata locality about one mile south of Mt. Zion church, 
in Hellam township, and four miles northeast of York, numer- 
ous specimens of Camerella minor and fragments of Olenel- 
lus occur in a calcareous quartzite identical in character with 
that of the Emigsville section. These two localities prove 
that the Scolithus quartzites of the Hellam hills and of 
‘““Chiques Rock” are beneath the Olenellus calcareous quartz- 
ite of the Emigsville section and, therefore, of Lower Cam- 
brian age. 

Search was next made for fossils near the base of the lime- 
stone above the ferriferous shales resting on the quartzites of 
Hellam hills. .They were found at a short distance above the 
shales in a small quarry of thin-bedded limestone by the road- 
side, one and one-eighth miles north of Stoner’s station on the 
York & Wrightsville railway. The strike is a little north of 
west, and dip 45° south. Finely preserved specimens of 
Linnarssonia, closely allied to JLinnarssonia sagittalis are 
abundant, and easily recognized fragments of a species of 
Olenellus are associated with them. Crossing the section to 
the south, occasional exposures were seen of massive bedded, 
light-colored limestones, much of the same character as those 
exposed in the quarries north of Wrightsville three miles to 
the eastward. The dip increased to 85° at the railroad track, 
which indicated that a compressed synelinal had been passed 
over in the section. The only locality where fossils were 
found within the main body of the limestone in York County 
was one and one-half miles southwest of the public square at 
York, Pa., on the north side of Highland Park. The species 
recognized are: one closely allied to Olenoides Marcowi, Pro- 
typus senectus, and two species of Ptychoparia, all of which 
belong to the Lower Cambrian fauna. When examining the 
section on the east side of the Susquehanna, in Lancaster 
county south of Columbia and north of Washington Manor, 
with Messrs. A. Wanner and Arthur Keith, a locality of lower 
Cambrian fossils was found in a narrow belt. of limestone 
about half a mile north of Washington Manor. Hyolithes 
communis and fragments of Olenellus showing portions of the 
head and thoracic segments were recognized in the material 
collected. 


©. D. Walcott—Cambrian Rocks of Pennsylwania. 415 


A glance at Dr. Frazer's map of York county shows that it 
is probable that all of the limestones, quartzites and schists of 
the central portion of the country are of Lower Cambrian age. 
The Hellam quartzite ridge is, as stated by Dr. Frazer, evidently 
an anticlinal ridge broken on the northwest side by a fault that 
has brought the quartzite up against the higher horizons of the 
shales and limestones. The anticlinal structure apparently 
extends to the southwest past York and towards Hanover.* 

The discovery of Lower Cambrian fossils in the compressed 
synclinal of limestone in Laneaster county, south of Columbia, 
indicates that the limestone on the west side of the river is of 
the same geological age; and that the shales and schists beneath 
it (called chlorite schists, ete., by Frazer) are of Lower Cambrian 
age; and I doubt if there is a sedimentary rock,—other than 
the Mesozoic New Red sandstone—of later age than the Cam- 
brian in York county, unless it may possibly be the Peach 
Bottom slate and chlorite schists of the southeastern corner of 
the county ; and from the closely related structure of Lancaster 
county it is probable that all of the Lancaster limestones will 
fall within the Cambrian unless it be that some portions of 
the upper series of limestone may pass into the Ordovician. 
This generalization will also apply to the limestones of the 
adjoining counties of Berks and Chester and, in fact, to the 
entire extension of this series northeastward, to the Delaware. 
All of the quartzites, that have been referred to the Potsdam, 
will necessarily fall into the Lower Cambrian, as they are 
beneath the limestones. 

When it is once considered that the quartzites, called the 
Potsdam by the Pennsylvania Survey, are of Lower Cambrian 
age; that a series of shales and limestones, superjacent to these, 
are of Lower Cambrian age: that the Potsdam ‘horizon of the 
New York series is represented by limestones in the Auroral 
series of Rogers; and that the Calciferous-Chazy terrane of the 
New York section is represented only by the upper portions of 
the Auroral limestones, geologists will have little difficulty in 
determining the geologic horizons of the various outcrops of 
quartzites, schists, shales and limestones,—provided careful 
attention is paid to their sedimentary character and to the dis- 
covery of occasional localities of fossils. 


South Mountain. 


Prof. Lesley states that “the South Mountains,” separating 
the Cumberland valley from the lower country of York and 


* Southeast of the Hellam hills the iimestones appear to form a compressed 
synclinal and this structure way extend to Hanover and beyond to the S.W. 
My time was too limited to study the details of structure off of the line of the 
sections mentioned in these notes. 


- 


476 C0. D. Walcott—Cambrian Rocks of Pennsylvania. 


Adams counties, form the northernmost end of the Blue Ridge 
range of Virgimia. .. .. . The whole measures upon the 
map ten miles in breadth by fifty in length upon a curve ex- 
tending from the Maryland line to its eastern edge, fifteen 
miles west of Harrisburg.* 

From the Pennsylvania line southwest across Maryland, 
South Mountain extends, as the Blue Ridge, to Harper’s Ferry, 
and thence southwest across Virginia. It, also, practically 
includes the Cotoctin range, on the eastern side, which extends 
south from the southwestern portion of Adams county, Penn- 
sylvania, and crosses the Potomac at the Point of Rocks, and 
from thence extends south a little west of Leesburgh, Va. 
The Blue Ridge and the Cotoctin Ridge are the eastern and 
western sides of the mountain uplift of which the South Moun- 
tain, Pennsylvania, is the northern terminus. 

The classification of the rocks of Pennsylvania was summed 
up by Prof. H. D. Rogers as follows:—The Hypozoie rocks, 
or those underneath any life-bearing strata; Azoic, or those” 
destitute of any discovered relics of life; and Paleozoic, or 
those entombing the remains of the earth’s most extinct forms 
once living beings.t 

It is evident from Prof. Rogers’ definition of the Azoic 
group, that it included what we now recognize as the lower 
Cambrian sedimentary strata beneath the Scolithus quartzite 
and, also an extended: series of altered rocks that form the 
nucleus of the Blue Ridge, and which are now included in the 
Algonkian of the classification of the U. 8. Geological Survey. 
He regarded the sandstone with. Scolithus linearis as at the 
base of the Paleozoic series, and considered that the Primal 
slates beneath the sandstone, and in intimate alternation with 
it, did not possess a vestige of organic life. 

The conclusions of the geologists of the second geological 
survey of Pennsylvania, are that there are two groups of rocks 
forming South Mountain. 

Prof. Lesley says: “The northwestern (Mt. Holly) ridge is 
made by several thousand feet of the lower quartzite and quartz 
conglomerate beds. The southeastern (Adams county) ridges 
are made by several thousand feet of an overlying feldspathic, 
micaceous and chlorite series, intersected by veins of milky 
quartz.’t .... “Itis hard to avoid the inference that our 
South Mountain rocks represent the Huronian section of Murray 
and Logan. It is impossible not to compare them also with 


*Second Geol. Survey of Penn. A summary description of the geology of 
Penn., vol. i, 1892, p. 142. 

+ The Geology of Pennsylvania, vol. i, 1858, p. 64. 

t Second Geol. Surv. of Penn. A summary description of the geology of Penn- 
sylvania, vol. i, 1892, p. 144. . 


C. D. Waleott—Cambrian Rocks of Pennsylvania. 477 


the great quartzite masses, the roofing slates, etc., of Walcott’s 
upper, middle and lower Cambrian system.”* 

When I began the investigation to ascertain, by stratigraphic 
and paleontologic evidence, the geologic age of the South 
Mountain quartzite and the associated schists and slates, I soon 
discovered that there was very little prospect of finding the 
true geologic succession in the northern portion of the moun- 
tain, in Cumberland and York counties, owing to the folding 
of the strata and also to the fact that there were a number of 
westward thrusts of lower on higher beds, and that as a result 
of this the central core of the Blue Ridge had been broken and 
thrust over on the Lower Cambrian beds and, also, in places, 
resting apparently conformably upon the latter,—all having an 
eastward dip. The discovery of Olenellus with Hyolithes com- 
munis in the massive quartzite series in the Mt. Holly ridge, 
just above Mt. Holly Springs in Cumberland county, proved 
that the great western mass of quartzites of South Mountain, 
with the interbedded shales, slates and conglomerates, were of 
Lower Cambrian age; but it did not throw light upon the geo- 
logic age of the orthofelsite series of Frazer and the epidotic 
rocks of Rogers. In company with Mr. Arthur Keith, of the 
U.S. Geological Survey, who had mapped the Harper’s Ferry 
sheet, an examination was made across the ridges, from Mechan- 
icstown, Md., to Monterey and westward to Pikesville, in 
Franklin county, Pennsylvania. 

‘On entering the gorge, a little west of Mechanicstown, on 
the line of the Western Maryland R. R., an extended series of 
shales and slates was passed,—all having a very high dip to 
the southeast. About two miles from Mechanicstown, massive 
quartzites were observéd with a high dip to the east, and, 
higher up in the gorge, there was a repetition of the slates 
found east of the quartzites. This section, from the dip of 
the quartzite, indicated a synclinal resting on a considerable 
thickness of slates and shales. A series of sections, by Mr. 
Keith, of the western, or Blue Ridge ridge extending from a 
point eleven miles south of Mechanicstown to Harper’s Ferry, 
shows that this same synclinal structure prevails all along the 
ridge, and that a synclinal fold of massive sandstone forms the 
summit of the ridge, below which a series of shales rests 
unconformably upon the subjacent crystalline rocks.t The 
synclinal structure is also shown for the quartzites of the 
eastern or Cotoctin ridge. 

From a point two and one-half miles west of Mechanics- 
town to Monterey, the road led across the epidotic schists of 

* Loc. cit., pp. 147, 148. 


+ The structure of the Blue Ridge near Harper’s Ferry. Bull. Geol. Soe. 
America, vol. i, 1891, pls. 4 and 5, 


478 ©. D. Walcott—Cambrian Rocks of Pennsylvania. 


the central mass of the range, which is now a mountain 
valley between the Cotoctin and Blue Ridge ridges. The 
schist extends to a point one-fourth to one-half a mile beyond 
the Blue Ridge station, on the Western Maryland BR. R. 
Fragments of a rhyolite-like, porphyritic rock* were also seen, 
that probably represent the ‘‘ bedded petrosilex” of Dr. Hunt, 
as shown two miles south of this Monterey road, near Fox- 
ville, Maryland. Going down the road beyond Pen Mar 
towards Pikesville, there was an apparent repetition of the 
section on the eastern side of the ridge, near Mechanicstown. 
Subsequently, an examination was made of the section from 
Monterey, Franklin eounty, Pennsylvania, to the valley on the 
line of the Waynesborough turnpike. Just west of Monterey 
a massive quartzite forms a plateau, upon which the Monterey 
hotel is situated. The dip of the quartzite is slightly to the 
northwest. A short distance beyond the toll-gate the dip to 
the northwest increases, and a series of sandy and argillaceous 
shales sueceeds the quartzite. Following down the turnpike 
toward Waynesborough and near the foot of the ridge, these 
shales were found to pass beneath a light-colored, hard, com- 
pact quartzite dipping northwest, in which numerous remains 
of Scolithus linearis occur. By breaking the white quartzite 
many fragments of Olenellus showing parts of the head and 
thoracic segments were also found. In calcareo-arenaceous 
layers, just beneath the quartzite, fragments of Olenellus 
occur associated with specimens of Camerella minor. A series 
of more or less sandy shales next appears resting upon the 
Scolithus quartzite and having a northwesterly dip, toward 
the valley. Along the foot of the ridge, low hills of sandy 
shale and slate appear, capped with a thin-bedded calcareous 
quartzite or sandstone. In the latter, Camerella minor, 
fHyolithes communis, and fragments of Olenellus are abundant. 
A little west of these hills the limestones of the valley appear. 
In this limestone, Awutorgina n. sp., and fragments of the head 
and thoracic segments of Olenellus were found a little east of 
the road leading up the east branch of Little Antietam creek 
and about three miles east of Waynesborough. 

If reference is now made to the York county section it will 
be seen that the upper pertion of the Monterey section is 
essentially a repetition of it—from the Scolithus quartzite to 
the limestones of the valley. ‘The same fossiliferous Scolithus 
quartzite passes beneath sandy shales and slates, in which are 
interbedded calcareous quartzites carrying the Olenellus fauna ; 
these pass beneath the limestones of the valley in York 
county in which the Olenellus fauna occurs. In the Monterey 


*The description of the volcanic rocks of South Mountain by Dr. G. H. 
Williams is contained in the following article, p. 482. 


C. D. Walcott— Cambrian Rocks of Pennsylvania. 479 


section, however, there is in addition a series of shales beneath 
the Scolithus quartzite. that rests upon a massive quartzite 
forming the summit of the Blue Ridge, west of Monterey and 
beneath this a bed of slates unconformable to the subjacent 
crystalline rocks. : 

The Blue Ridge was followed south into Maryland and 
crossed at several points before reaching Harper’s Ferry. All 
of the section shows the synclinal structure of the slates and 
quartzites as represented by Messrs. Geiger and Keith, in their 
paper upon the structure of the Blue Ridge near’ Harper’s 
Ferry.* South of Keedysville, Washington county, Mary- 
land, the quartzite, capping the slate hills west of the main 
ridge, was observed to pass conformably beneath the limestone 
at Eakle’s Mills, and fyolithes communis and fragments of 
Olenellus were found in the calcareous quartzite. The rela- 
tively simple stratigraphic structure of the Monterey section 
is complicated at, and near, Harper’s Ferry by the lower 
massive quartzite forming a synclinal and being thrust to the 
westward over the more recent shales, slates and limestones. 
The structure is still more complicated by the fact that the 
hills of sandy shale and slate (capped by the upper Olenellus 
quartzite) are thrust, on the line of a fault, over on to lime- 
stones which, in an unbroken section, rest upon the quartzites. 

It was this primary folding and subsequent westward thrust- 
ing, on the line of two or more faults, of the older upon the 
more recent strata at and to the north and south of Harper’s 
Ferry that led Messrs. Geiger and Keith to consider that the 
lower quartzites rested conformably upon the limestones and 
were of Silurian age.t 

Returning to South Mountain with the information gained 
between the Potomac and the line of the Chambersburgh and 
Gettysburgh pike, in Pennsylvania, and studying Dr. Frazer’s 
sections (Nos. 7, 8, 9, 10, 11 and 13)t and also reading the 
descriptions of them, as well as Professor Lesley’s description 
of South Mountain (contained in Vol. I of his final report), 
it is evident that they have misinterpreted the true geologic 
structure of the mountain and the relations of the rocks com- 
posing it. Professor Lesley states that a massive fault must 
run along the foot of the mountain, along the low drift-filled 
valley of Yellow Breeches creek ; and this I think is correct, 
as the Olenellus fauna of the Scolithus quartzite zone occurs 
but a short distance east of the foot of the mountain, in a syn- 


* Bull. Geol. Soc. America, vol. ii, 1891, pls. 4 and 5. 

+ Loe. cit., pls. 4 and 5. A paper by Mr. Arthur Keith describing his present 
view of the structure will be found in the Dec. No. of the Am. Geologist for 1892. 

¢ Second Geol. Sury. Pa. Report of Progress in the counties of York, Adams, 
Cumberland and Franklin for 1875 published 1877. 


Am. Jour. Sc1.—Tuirp SERIES, VoL. XLIV, No. 264.—DECEMBER, 1892. 
32 


480 C.D. Walcott—Cambrian Rocks of Pennsylvania. 


elinal fold, at Mt. Holly Springs. Their error, however, is in 
considering that the ‘“ orthofelsite” series is superior to the 
conglomerates, quartzites and schists which they referred to 
the Lower series. The Monterey section shows that the epi- 
dotic schists are inferior to the quartzites and slates and, a 
section west of Wolfsville, Md., that the “ petrosilex”” or rhyo- 
lite-like eruptive occupies a similar position. This type of 
section is repeated many times, both on the Cotoetin and Blue 
Ridge sides, from the Maryland line to the Potomac and south 
through Virginia. : 

Professor Rogers and also Professor Lesley, referred the 
offsets of the ranges of hills of South Mountain, as shown in 
Franklin county and also on the north end of South Mountain, 
to the terminations of successive folds of the rocks forming 
the mountain. My impression is that these offsets and also the 
complicated structure of the mountain arise partly from fold- 
ing, but more largely from the westward thrusts of masses of 
strata along the line of faults of a low hade. This westward 
thrusting on the fault planes, complicated by previous foldings 
of strata, leaves masses of the subjacent pre-Paleozoic rocks 
resting, in various places, on different members of the lower 
Cambrian series, and also appears to interbed the quartzites 
and slates of the Cambrian in the schists, eruptives, ete., of 
the Algonkian.* 

The key to the succession of the lower sedimentary rocks of 
Maryland and Pennsylvania is contained in the Balcony Falls 
section of Virginia, although it can now be determined by a 
study of the section at Monterey and to the south, along the 
Blue Ridge toward Harper’s Ferry. 

In a letter received from Professor Lesley and dated Feb- 
ruary 22d, 1891, he asks: ‘Is it impossible that there should 
be agreement between the Balcony Falls section of Virginia 
and the Mt. Holly Springs section, three hundred miles apart ?” 
He says, further, after commenting upon the possible relations 
between the Balcony Falls section and that at South Mountain, 
in speaking of the strata of the Balcony Falls section: ‘ But 
what is 2,000 feet or 2,500 feet to 10,000 feet to 20;000 feet of 
quartzites and slates making (apparently—not certainly—) the 
South Mountains? We are still in the dark about super- and 
sub-positions ; about absence or presence of overturn rolls, ete. 
I am only greatly impressed with the broad fact that we seem 

* From the finding of fragments of the eruptive rocks in the conglomerates at 
the base of the quartzite series, and from the numerous synclinals showing that 
the epidotic rocks and also certain rhyolitic cruptives are beneath the quartzite 
series I refer the similar rocks of South Mountain to a pre-Paleozoiec age; and, 
as they are not of the character of the Laurentian crystalline complex, I would 


refer them to the Algonkian, but not correlate them with the Huronian or with 
any known division of that group of rocks. 


OC. D. Walcott—Cambrian Rocks of Pennsylvania. 481 


to have the Huronian mass rising to view in the South 
Mountains of the Atlantic States.” 

I think that the view of Messrs. Frazer and Lesley that such 
ereat thicknesses of strata occur in South Mountain arises 
from the fact that these “ great thicknesses” are but repeti- 
tions of both the Cambrian and pre-Cambrian strata from 
foldings and overthrust faultings and also from their not dif- 
ferentiating between the cleaved schistose eruptives of the 
Algonkian and the bedded.and often cleaved sedimentaries of 
the lower Paleozoic. 

The section at Monterey and along that portion of the Blue 
Ridge is roughly, as estimated from the data obtained by Mr. 
Keith to the south and from the Monterey section, reading 
from below upwards, as follows :. 


Feet. 
1. Shales, and slates, well shown near Mechanicstown, 
Maryland, and in numerous sections along the Blue 
J ESIC Ces esa set rs cone ie Mle 300 feet to 400 
2. Coarse-grained and bluish-gray quartzite _--.--- 1000 to 1200 
At several localities the shales of (1) appear to be 
replaced by bands of conglomerate and shale ; and many 
of the layers of (2) are conglomeritic to a greater or less 
extent. 
3. Sandy shale, with interbedded layers of quartzite--..__- 800 
4. Scolithus quartzite, with interbedded calcareous sand- 
(SERLOTMICAS) MN PEAVY CEI ee a Fe Ta ee eae 500 
Fossils :—Camerella minor, and fragments of Ole- 
nellus. 
5. Sandy shales, with a series of calcareous quartzite near 
titetsumanatt) tral out ae senete Chics eM aa Cs Geeta aie 8 450 
Fossils :—Camerella minor, Hyolithes communis, 
and fragments of Olenellus. 
6. Mottled limestone, with intercalated sandy and shaly 
Ne SES SA ag is 0 ae ae eg en 800 to 1000 
Fossils :—Kutorgina vn. sp., and fragments of Ole- 
PACA UN es ala ess cs see arin DAI ea UMN ps ek ale aca 
This portion of the section is succeeded by the valley 
limestone, more or less of the lower portion of which is 
probably of middle and upper Cambrian age. 


The section includes from 3,000 feet to 3,500 feet of sand- 
stones and shales before reaching the limestones. In a number 
of localities a conglomerate was observed in the Lower sand- 
stone series, in which fragments of the pre- Paleozoic crystalline 
rocks were imbedded. This phenomenon was observed on 
South Mountain, in the conglomerates mentioned by Prof. 
Lesley, and also along the Blue Ridge and the Cotoctin ridge 
to Harper’s Ferry; the conglomerate character of the rock 


482. G. H. Williams— Volcanic Rocks of South Mountain 


varying very much in the character and size of the coarser 
material. The feldspathic character of these shales and sand- 
stones is very distinctly marked beneath the Scolithus quartz- 
ite, both in the Balcony Falls and the Monterey sections. 

If these two sections are eompared with that at ‘“Chiques 
Rock” and south to Columbia, in Lancaster county, Pa., it 
will be at once observed that the Scolithus quartzite, while 
the highest band of quartzite in the Balcony Falls and the 
Monterey sections, is the lowest in the ‘Chiques Rock” see- 
tion which has the lower feldspathic sandstone and shales 
apparently above the Scolithus quartzite. It is from this fact 
that it is stated, in the first part of this paper, that the feld- 
spathic sandstones and shales were thrust over on the Scolithus 
sandrock in the ‘“* Chiques Rocks” section. 


Art. LXV.—The Volcanic Rocks of South Mountain in 
Pennsylvania and Maryland ; by GEorce H. WILiiAMs. 
With Plate X * 


Contents.—1. Object of this paper. 2. Supposed sedimentary origin of the 
South Mountain voleanic rocks. 3. Petrographical character: a) The acid rocks 
—rhyolites; b) The basic rocks—basalts; c) The pyroclastic deposits—tuffs and 
breccias. 4. Geological occurrence and relations to the sandstone. 5. Chemical 
alteration and metamorphism. 6. Comparison with other regions. 


[Read before the National Academy of Sciences, Nov. 2, 1892.] 


1. Object of this paper.—lt is the object of the present 
communication to announce the identification of an extensive 
area of very ancient volcanic rocks which compose an im- 
portant part of the South Mountain, south of the Susquehanna 
River. The brief preliminary description of these rocks, 
which is all that can now be attempted, will, it is hoped, suf- 
fice to show that the hitherto accepted theory of their sedi- 
mentary origin has been based on a misinterpretation of the 
facts which they exhibit. 

The rocks in question preserve abundant and convincing 
evidence—both structural, chemical, and petrographical—of 
their original character and genesis. At the same time they 
show various phases of alteration by recrystallization and 
dynamic agencies which render them valuable for the study of 
many problems of metamorphism. 


* The writer is under great obligations for many of the facts contained in this 
paper to Miss Florence Bascom, who has mapped in great detail one of the most 
diversified portions of South Mountain, near Monterey, Pa. She has collected a 
large material upon which she is now at work at the Johns Hopkins University, 
and her results, to be published in due time as a thesis, will go far toward fur- 
nishing detailed proof of the general conclusions here set forth. 


in Pennsylvania and Maryland. 483 


Mr. Howey fh) eee 


=" Voleanic Rocks 
of the } 
South eMountain 


Pornaylvanio §Monwland 


g 
George H.Williams. 
1892. 


Scare of Mites 


Re ee RR SSX 


Breccia Sandstone Limestone 
(volcanic) — (Cambrian) 


484 G. H. Williams— Volcanie Rocks of South Mountain 


South Mountain rises about fifteen miles west of Harris- 
burg and extends, as may be seen on the accompanying map, 
in a ereat sickle- shaped curve to the Maryland line. Here it 
divides into two parts, known as Catoctin Mountain and the 
Blue Ridge, which diverge at a small angle and enclose the tri- 
angular Middletown valley, north of the Potomae. 

During the past summer the writer devoted considerable 
time to mapping the volcanic rocks of this region and to col- 
lecting suitable material for laboratory study. This has at 
present only been fairly entered upon, so that subsequent com- 
munications giving more detailed results, may be expected. 

2. Supposed sedimentary origin of the South Mountain 
Volcanic rocks.—As far as is known to the writer, volcanic 
rocks have not hitherto been definitely described as such in the 
Appalachians. The rocks here under consideration have long 
been known to geologists, but they have before, with the ex- 
ception of a few of the most massive greenstones, been gen- 
erally regarded as of sedimentary origin. 

Professor Henry Rogers in 1858 speaks of South Mountain 
southwest of the Susquehanna, as embracing ‘“‘a singularly 
small amount” of igneous rock. He alludes to the cleaved 
greenstones as “dark green slate,” and to the acid porphyries 
and felsites as “ highly metamorphic Primal slate.” He con- 
tinually contrasts the highly altered slate and the unaltered 
sandstone,* although in reality one rock is scarcely more 
changed than the other. 

Philip Tyson, in his first report as State Agricultural 
Chemist made in 1860, speaks of the sandstone of South 
Mountain as Potsdam and says that it contains fossilized stems 
of plants. He also says: “A slate, varying in color from gray 
to brownish and greenish, is ranked as an argillite, but portions 
of it assume a marked talcose appearance, especially in Catoc- 
tin mountain, where it has been much disturbed and altered 
by proximity to intrusive rocks. These last consist of amphi. 
bolites (trap), porphyries, amygdaloid, serpentine and epi- 
dote.”’+ 

In 1877 appeared the results of Dr. Persifor Frazer’s studies 
of South Mountain. He regarded it as composed essentially 
of a westerly (older) portion, consisting of various modifica- 
tions of a quartz-conglomerate (Mountain Creek rock) and an 
easterly (younger) portion composed of orthofelsite, inter- 

* Geology of Pennsylvania, vol. i, pp. 203-5, 1858. 

+ First Report of P. T. Tyson, State Agricultural Chemist, to the House of 
Delegates of Maryland, January, 1860, pp. 34, 35 (ef. also p. 18). In his second 
report (1862. p. 70) he gives further particulars regarding Catoctin Mountain. He 
Says ‘fa vast mass of epidotic trap, five miles wide, was forced up from below in a 
state of fusion. This embraces a mass of chert (rhyolite) 3000-4000 feet thick.” 


He describes the trap as carrying metallic copper, and regards it as the cause of 
the elevation of the mountain sandstone. 


in Pennsylvania and Maryland. 485 


bedded with hydromica and chloritie schists.* Regarding the 
origin of these latter rocks, which like the conglomerate were 
placed below Rogers’ primal sandstone, Dr. Frazer made the 
following statement in 1877,+ repeating it two years later :{ 
“The porphyry which carries the copper of this region shows 
no character of igneous action, but occurs in coarse and thin 
beds, more or less disintegrated, and in some localities reduced 
almost to the state of kaolin.” 

Dr. T. Sterry Hunt announced to the American Association 
for the Advancement of Science in 1876 that he had identi- 
fied petrosilex or hiilleflinta in South Mountain, which he had 
examined with Dr. Frazer. Dr. Hunt’s concurrence in 1879 
with Dr. Frazer’s opinion above cited, and his constant use of 
the term bedded petrosilex sufficiently indicate that he re- 
garded these rocks as sedimentary. He however correctly 
compares the South Mountain rocks with others in Missouri, 
the Lake Superior region, eastern Massachusetts, Maine, and 
New Brunswick, since shown to be voleanic, although he saw 
in this similarity only evidence of their ‘“ Huronian” age. 

The nearest approach to a recognition of the South Mountain 
‘rocks in Pennsylvania as volcanic was made by Mr. J. F. 
Blandy, who described the copper-bearing rock in 1879 as 
amygdaloid trap, and correlated it with the similar flows near 
Lake Superior. The acid felsites however were regarded by 
Mr. Blandy as slate. | 

In his recent final volume on the Geology of Pennsylvania, 
Professor Lesley follows in the main Dr. Frazer’s classification 
of the rocks of South Mountain. Although he considers that 
the sandstone probably represents the “ Huronian” of Logan 
and Murry, he says it is impossible not to compare it with 
Walcott’s Cambrian System. The supposed overlying feld- 
spathic felsite series (orthofelsite of Frazer) Lesley estimates 
as 6,000 feet in thickness, and everywhere speaks as though he 
regarded it of sedimentary origin. 4) 

‘The cause of the prevailing misconception regarding the 
voleanie rocks of South Mountain is not difficult to find. 
Their accompanying accumulations of tuff beds and breccias, 
and the fact that they are generally cleaved parallel to the 


* Report of Progress in the counties of York, Adams, Cumberland and Frank- 
lin. Second Geol. Sury. of Penn. CC for 1875. Harrisburg, 1877, p. 285. 

+‘ Copper Ores of Pennsylvania.” Polytechnic Review, vol. iii, p. 170, April 
28, 1877. 

+ Trans. Am. Inst. Min. Engineers, vol. vii, p. 338, 1879. 

§ Proc. Am. Assoc. Adv. Sci., 1876, pp. 211, 219, and Second Geol. Survey of 
Penn., vol. H, 1878, p. 193. 

|| ‘The Lake Superior Copper Rocks in Pennsylvania.” Trans. Am. Inst. Min. 
Engineers, vol. vii, p. 331, 1879. 

§| A Summary description of the Geology of Pennsylvania by J. P. Lesley, 
State Geologist, vol. i, p. 146, 1892. 


486 G. H. Williams— Volcanic Rocks of South Mountain 


great structure-planes of the mountain, have all been readily: 
interpreted as indications of stratification and conformity. The 
cleavage-dip in the sandstone has often been mistaken for bed- 
ding, while the thin jointing and slaty structure of the lavas, 
though a secondary feature, have seemed to geologists not 
very familiar with recent volcanic rocks, sufficient proof of 
sedimentary origin. 

In spite of great age and some alteration, however, the 
voleanic rocks of South Mountain have preserved all the 
essential characteristics of our recent rhyolites and basalts in 
such perfection that the proofs of their real nature are, to the 
student of comparative petrography, overwhelming, while to 
all who will candidly examine them they must be at least con- 
vincing. 

3. Petrographical Character.—Approximately 175 square 
miles of the area of South Mountain is occupied, between Mt. 
Holly and the head of the Middleton valley, with volcanic 
rocks. These belong to two types which exhibit sharp con- 
trasts of color, composition and weathering. One type is 
inclined to tints of red, pink, blue, or purple; is acid in com- 
position ; generally porphyritic ; and weathers into thin slabs. 
The other type is almost invariably of a green color; basic in 
composition; frequently amygdaloidal; and weathers into 
rough, angular blocks. The rocks of the first type have been 
called felsite, orthofelsite, porphyry, or petrosilex; those of the 
second, trap, greenstone, chlorite-slate, or epidote-slate. In 
view, however, of the perfection with which these rocks have 
preserved the most characteristic features of their modern 
equivalents, there is no reason why they should not, like them, 
be termed rhyolites and basalts. The insignificance of mere 
age as a factor in rock nomenclature is now so fully recognized 
that we may with propriety employ the names of our recent 
lavas for rocks of any geological horizon, when we can prove 
beyond doubt their identity. 

It is, of course, to be expected that many rocks of inter- 
mediate character will be found within this volcanic area. 
Since the petrographical and chemical study has, however, 
only begun, and since the contrast above noted is so well 
defined, the distinction of two types may at present be regarded 
as sufficient. 

a). The acid rocks, rhyolites—The rocks of the acid type 
occupy somewhat more than two-thirds of the volcanic area of 
South Mountain—(see map). They occur in dykes and flows 
forming a body of great thickness; they are accompanied by 
ashes, tuffs and breccias; they are usually porphyritic, though 
not always so; they exhibit the characteristics of recent glassy 
and half-glassy rocks—tflow-structures, perlitic structure, litho- 


in Pennsylvania and Maryland. 487 


physae, spherulites (in masses, in layers and in chains), axiolites, 
pumice, amygdaloids, ete., etc.—in hardly less perfection than 
the specimens which Professor Iddings has so admirably 
described from the Yellowstone Park. 

These structures are preserved, in spite of the recrystalliza- 
tion of the entire rock-substance into a fine mosaic. They are 
therefore most apparent in hand specimens, especially when 
brought out by weathering; or, under the microscope, they 
are better seen in ordinary than in polarized light, as was the 
case with the old glass breccia, recently described by the writer 
from the Sudbury region.* 

The following is an analysis of a rhyolite specimen from 
the Gladhills road, near the Bigham Copper mine, on the 
north side of Pine Mountain, made by Mr. C. Hanford Hen- 
derson of Philadelphia, and published in 1884.+ This is a 
quite typical rhyolite analysis. When compared with analyses 
of our most recent acid lavas, the iron may seem a little high 
and the alumina a little low, but on the whole the close agree- 
ment is a surprise. 


PO) ce cna Bara ee a age A 73°62 
PNICO) Sein amma 12:22 
Het ORB ee erer ene etn 25/2 5 a 2°08 
ORIN Ee eng ea rietece Praha Oneabae 4°03 
CAO ea EUR ee RL 0°34 
IN Ogee irae Drea yer 0 a 0:26 
EINE) 2s Wee tire ance ae WR A 3°57 
ER Oia areca SI yaa Dosey 
dca le NS ee el gee cP 0°40 

NOLEN Lk seein ear ean, Jee ee OI 99°09 


The macroscopic features of the rhyolite are the best proofs 
of its true nature, for weathering brings out on the surface of 
the rock each delicate detail. In this way we discover every 
characteristic of glassy rocks, though there is no glass now 
remaining. Plate X, fig. 1, shows in photographic reproduc- 
tion a specimen five inches long, covered with lithophyse as 
perfect as any the Yellowstone can furnish. ‘Their delicate 
petals are a pale pink, while the base has weathered white. 
With a lens the radiating and minutely fluted, concentric struc- 
ture can be traced distinctly. Fig. 4 (p. 488), gives a some- 
what diagrammatic idea of this structure. 

Plate X, fig. 2, shows the delicate lines of flow-structure as 
they are displayed on the weathered surface of a specimen which 


* Bull. Geol. Soe. Am, vol. ii, p. 138, 1891. Ann, Rept. Geol Surv. Can. for 
1889-90, F, p. 75, 1891. 

t ‘The Copper Deposits of South Mountain,” by C. H. Henderson. Trans. Am. 
Inst. Mining Engineers, vol. xii, p. 90. 


488 G. H. Williams— Volcanic Locks of South Mountain 


in its interior is a homogeneous, dark purple felsite. On 
other specimens these flow lines are even more sinuous. This 
specimen was merely selected from a great variety because it 
appeared well-fitted for reproduction. 

At some localities the rhyolite is crowded with spherulites. 
Plate X, fig. 3, represents a large specimen found north of 
the junction of Copper run with Tom’s Creek. Here the 
spherulites make most of the mass and have no regular arrange- 
ment. They have the size of large peas. In other cases the 
spherulites are of smaller size and more sparsely distributed. 
They are then not infrequently arranged in layers as described 
by Iddings in the Yellowstone obsidian.* One specimen from 
Raccoon Creek (No. 148) shows small but very perfect, grey 
spherulites distributed, singly, in layers or in large aggregates 
through a black base which was once probably obsidian. In 
appearance it is not unlike the well known specimens from the 
Lipari Islands. 


Fig. 4. Structure of a lithophysa brought out by weathering—natural size— 
No. 129, from Raccoon Creek. 

Fig. 5. Hand specimen showing chains of spherulites—No. 78, from near Snowy 
Mountain. 


Another very common arrangement of spherulites is shown 
in fig. 5. Here they occur in single layers, which, in 
cross-section, appear like chains, bent more or less out of their 
normal horizontal position by the flow-motion of the magma. 
The individuality of these spherulites is preserved, though they 
are so merged into one another that they approach the axiolitie 
structure. This structure is so frequent that it has doubtless 
helped confirm the idea that the felsite and porphyries were 


* Obsidian Cliff, 7th Ann. Rept. U. 8. Geol. Svrv., p. 276, Plate xviii, 1888. 


in Pennsylvania and Maryland. 489 


stratified. It seems to be quite independent of the presence or 
absence of phenocrysts in the rock. 

Still another characteristic, which the South Mountain rhyo- 
lites possess in common with many recent lavas, is what we 
may call the ewtaxitie structure.* This consists of the close 
intermingling of two portions of the magma which, on account 
of some slight differences in chemical composition or hydra- 
tion, show a marked contrast in color. The two portions may 
be, for instance, black and white, pink and blue, or red and gray. 
They mingle so as to produce in some cases an irregular mott- 
ling; in others a complex series of interlacing bands which 
bring out the flow-structure in a striking manner. Specimen 
No. 145, from Raccoon Creek, shows small black areas resemb- 
ling shreds of glass, imbedded in a pink base which, ona 
weathered surface, appears snow-white. 

Amygdaloidal structure, representing old vesicles more or 
less elongated by motion in the viscous mass, is much less com- 
mon in the acid, than in the basic rocks. Fine examples of it 
were, however, found at the Bigham Copper mine; along 
Raccoon Creek and at the eastern end of the Jack’s Mountain 
tunnel (Nos. 20, 147 and 7). Asa microscopic feature this 
vesicular structure is still more common, (see fig. 6). Per- 
litic parting, so characteristic of glassy rocks, may be detected 
macroscopically in many felsite specimens. 

The microscopical characters of the South Mountain rhyo- 
lites are far too varied to be described in a brief paper like the 
present. It must suffice to say that, in spite of the recrystal- 
lization of the substance, we still find in great perfection all 
the essential features of the most recent acid lavas. Corroded 
and skeleton phenocrysts of quartz, micropegmatitic inter- 
growths of quartz in feldspar phenocrysts,t and phenocrysts 
broken by the flow movement. In the groundmass we find 
spherulitic tufts, axiolites, elongated vesicles filled with quartz, 
trichites and globulites in great variety, which bring out each 
detail of flow-structure. All the particulars of microscopic 
structure call for extended study and description. For the 
present purpose, however, which is merely to establish the 
character of these rocks, what has been said must suffice. 

In mineralogical composition the South Mountain rhyolites 
are quite uniform. When phenocrysts are present, the most 
abundant are alkali feldspar. Quartz in rounded bipyramids 
is always to be found with the feldspar under the microscope, 
although it is not so often apparent to the unaided eye. In 
only a single instance (No. 257D, from the head of Miney 

* Fritsch and Reiss: Tenerife, p. 414, 1868. Rosenbusch: Die Massigen Ge- 


steine, 2d Ed., p. 625. 
+ J. P. Iddings: loc. cit., p. 274 and Plate xv. 


490 G. H. Williams— Volcanic Rocks of South Mountain 


run) has any ferro-magnesian constituent as yet been detected. 
In this case biotite is abundant as an original mineral. The 
groundmass of the rhyolites is for the most part a quartz- 
feldspar mosaic of varying grain, much of which is the result 
of devitrification and recrystallization, though some of it is 
also probably original microgranite. 


Fig. 6 —Axiolitic and vesicular flow Fig. 7.—Flow structure. No. 61, 
structures. No. 77 from near Snowy South of Willow Grove, Pa., mag. 5 
Mtn., mag. 5 diameters. diameters. 


Attention has been called by Tyson,* Huntt and Frazert 
to the beauty of the South Mountain porphyries, and to the 
fact that they are so susceptible of a high polish as to make 
them valuable for decorative purposes. Many of them closely 
resemble the famous porfido rosso antico of Egypt, which is 
largely used by the lapidaries of Rome. 

b) The basic rocks, basalts.—The basic lavas of South 
Mountain occupy an area about one-half as large as that coy- 
ered by the acid ones. They reach their maximum develop- 
ment near the State line, where, along the southern edge of 
Pennsylvania and for a ‘considerable distance into Maryland, 
they form the entire width of the voleanic belt. North and 
south of this main body, the basie rocks or greenstones are 
everywhere met with as narrow bands intersecting the rhy- 
olites and following the general trend of the mountain. These 
bands differ much in their width, but seem to be most devel- 
oped along the eastern flanks of Green Ridge and Piney 
Mountain. 


* First Annual Report, 1860. Appendix, p. 3. 

+ Proc. Am. Assoc. Ady. Science, 1876, p. 212 (compares them with the Elf 
dalen porphyries). 

¢ Second Geol. Survey of Penn., vol. CC, p. 285. 


in Pennsylvania and Maryland. 491 


These rocks have been more generally sheared into slates 
than the acid lavas. The chemical alteration which has gone 
on in them is also in general greater. Still large masses of the 
basic rocks have been: but little altered and remain quite 
massive. ‘These, which are locally known as “copper rock,” 
are the only members of the volcanic series whose igneous 
origin has been heretofore conceded. They are for the most 
part very fine grained, vesicular flows, whose original structure 
is still so well preserved that they may with propriety be 
called basalts. 

The following analysis, also by Mr. C. H. Henderson, of a 
massive greenstone from the Bechtel copper shaft, Russel 
mine, is published by Dr. Frazer.* This is a normal basalt 
analysis, indicating as little chemical change in the basic rocks 
as the one given above does in the acid rocks. 


Siu wma eo eee 41280 
KOO eee ee 18-480 
a - 
ES io aes Ae i ea es Sng sl Cab Beatie RE A 

CAORs eet ye SE ty gh Pam shen 7040 
MeOun te Vie ees 7-486 
Tete aE ON ek er 
Dota eee ae nes 100:397 


Basic volcanic rocks never exhibit so great a variety of struc- 
ture forms as characterize the more acid rhyolites. The South 
Mountain basalts are usually homogeneous, dark to pale green 
masses which rarely show any microscopical phenocrysts and 
whose most constant feature is amygdaloidal structure. These 
cavities vary greatly in size, shape, and abundance. They are 
often elongated by flow-motion in the lava and are now filled 
with a number of secondary minerals, the most abundant of 
which are epidote, chlorite, quartz, and zeolites. Traces of 
original glass or spherulitic structure (variolite) have not yet 
been detected in the basalts. 

The mineral constituents of basic rocks are more subject to 
alteration than those of acid ones. It could not be expected 
that basalts so ancient and so vesicular as those of South 
Mountain would escape all change, but it is a surprise in many 
eases that this change has been so small. The ferro-magnesian 
constituents have always altered to epidote, chlorite or serpen- 
tine, but the structure is frequently preserved in its minutest 


* “ Hypothesis of the ‘structure of the Copper belt of South Mountain,” Trans. 
Am. Inst. Min. Engineers, vol. xii, p. 82, 1883-4. 


492. G. H. Williams— Volcanic Rocks of South Mountain 


detail.- Under the microscope the ophitic network of feldspar 
laths is still fresh, and the delicate twinning as distinct as in a 
recent lava. The form of the basaltic magnetite, of the olivine 
phenocrysts, and of the interstitial pyroxene is also plainly 
visible, while the arrangement of the feldspar microliths 
among the oval vesicles clearly indicates the motion of the 
still viscous mass. 

Fig. 8 gives two types of the basaltic structure. The one 
on the left shows skeleton phenocrysts of olivine and a fine 
grained, ophitic groundmass. 


LP 


CUSeY 


YAW 


Fig. 8, mag. 5 diameters. 


Left half—Basalt with skeleton olivines, ophitic structure, fresh feldspar. 
Amyedules filled with quartz and chlorite. Railroad, east of Monterey. Pa. 

Right half—Somewhat coarser grained basalt. Amygdules filled with zeolites 
and quartz grains. Railroad, east of Monterey, Pa. 


Both have large amygdules which are either oval or of 
irregular shape, and filled with different minerals. 

c) Pyroclastic deposits, tuffs and breccias.—As is generally 
the case with large accumulations of surface eruptions, the 
South Mountain lavas are accompanied by extensive deposits 
of pyroclastic material. This includes coarse flow- and tuff- 
breccias, pumiceous bombs, and banded accumulations of fine 
voleanic ash. Like the massive rocks, this fragmental matter 
is both acid and basic in composition. 

The most striking and important area of acid tuffs covers 
about a square mile in the Buchanan valley, at the eastern base 
of Piney Mountain, two miles north of the Chambersburg 
turnpike. Here the rock is a breccia whose component frag- 
ments vary from two or three feet in diameter to the finest 
ash. All sizes, shapes, and colors are heterogeneously mingled, 


in Pennsylvania and Maryland. 493 


and the result bears a superficial resemblance to the well- 
known triassic breccia (“ Potomac marble,” “ calico rock”) of 
the Frederick valley. The material in this case, instead of 
being limestone, is entirely rhyolite, and exhibits remarkable 
variety of structures and colors. Both flow- and tuff-breccias 
occur here, while a portion of the mass has been sheared into 
a quite fissile slate. Similar acid tufts, though of less striking 
appearance, occur at many other points (Raccoon Creek, Mon- 
terey, old Furnace road, etc.), and will doubtless continue to 
be discovered as the examination of the region proceeds. 

Fragmental deposits consisting wholly of basaltic material 
abound along the Western Maryland railroad near Monterey, 
and farther south. The finer cementing material is in these 
almost always altered to epidote. It is also not uncommon to 
find coarse breccias consisting of both the acid and basic types 
of rock, but a careful search has thus far failed to discover 
any fragments of sandstone in these pyroclastic beds 

4, Geological occurrence and relations to the Sandstone.— 
No evidence is necessary, beyond the petrographical charac- 
ters above described, to establish the igneous and volcanic 
nature of the South Mountain rocks. Additional evidence of 
a purely geological kind is not, however, wanting. The vicis- 
situdes through which these ancient rocks have passed, and 
their present inadequate exposure, tend to obscure their orig- 
inal relationships. Nevertheless dykes may be seen at various 
points, especially at the western end of the railroad tunnel on 
Jack’s Mountain, where an amygdaloidal red felsite cuts the 
massive and schistose greenstones. Further exploration will 
doubtless bring to light many similar occurrences. Successive 
flows are not now easy to separate, but the amygdaloidal and 
fluidal structure of the rocks indicates that they must have 
been extruded in this form. 

The age of the South Mountain volcanics and their relations 
to the sandstone in which Mr. Walcott has recently identified 
the lower Cambrian fauna, are points of great interest. The 
hypothesis of the Pennsylvania geologists that the green- 
stones and felsites lie above the sandstone is evidently incor- 
rect. It may, however, be regarded as an open question 
whether the volcanic rocks represent a much older horizon, 
which was already eroded before the sandstone was deposited, 
or whether they were, in part at least, contemporaneous with 
the sandstones. 

The entire absence of sandstone as inclusions in the lavas, 
as well as in all the accumulations of pyroclastic material ; 
the observations of Keith, Geiger* and Walcott,+ that the 


* Bull. Geol. Soc. America, vol. ii, p. 155; plates 4 and 5. 
+ This number of this Journal. 


494. G. H. Williams— Volcanic Rocks of South Mountain 


sandstone lies flat or in synclinals; and the sections made by 
Miss Bascom across Monterey Peak, Pine Mountain, Jack’s 
Mountain, and Haycock near Monterey, all indicate that the 
sandstone is altogether above the volcanic rocks, and that it 
has been only sporadically left by erosion on the east side of 
the mountain in Pennsylvania. In Maryland the. voleanic 
rocks are flanked both on the east and west by sandstone (see 
map). No alternations of relatively thin beds of sandstone 
and lava have thus far been observed. The contacts of the 
sandstone above the porphyry on the old tapeworm railroad 
southwest of Maria’s Furnace, and above the greenstone in the 
Jack’s Mountain railroad tunnel are both admirable exposures, 
but both seem to be thrust-planes and are not.contacts of original 
deposition. 

The South Mountain volcanic rocks therefore become, not 
merely in their petrographical character and richness in metal- 
lic copper, but also in their stratigraphical position, comparable 
with the Keewenawan or Nipigon series of Lake Superior. 

5. Chemical Alteration and Metamorphism. — Extensive 
chemical changes, involving devitrification and the formation 
of new minerals, have gone on in all the volcanic rocks of South 
Mountain without destroying the original structures. In other 
cases, where there has been movement and shearing, the same 
rocks have lost both their original minerals and structures by 
a process of complete metamorphism. ‘The results are more or 
less perfectly foliated schists and slates, whose origin can be 
positively traced to the voleanic rocks, and whose present form 
can be shown to depend upon the intensity of the dislocation 
to which they have been subjected. 

The chemical changes which have not affected the massive 
character of the rocks consist of the formation of new minerals 
to accord with the altered physical conditions. These have, as 
a rule, merely replaced the former minerals so as to leave the 
original structure of the rock intact. In the basic rocks the 
new minerals are epidote, fibrous green hornblende, chlorite, 
serpentine, iron oxide, and, to less extent, calcite and quartz. 
Of these by far the most important is epidote. Indeed the 
conditions for the formation of this substance must have been 
exceptionally favorable, as it has everywhere been produced in 
great abundance, Some of the finer material, like volcanic ash 
or breccia cement, is wholly altered to this mineral. It is 
also the most common filling of the amygdules. 

In the acid rocks there has been a complete reerystallization 
of all glass into a fine quartz-feldspar mosaic, which, however, 
still exhibits the original structures. The conditions favorable 
to epidote formation are manifest in these rocks in the presence 
of large amounts of the manganese epidote (piedmontite). 


in Pennsylvania and Maryland. 495 


This rare mineral is so abundant and occurs in such interesting 
relations that it will soon be made the subject of a special com- 
munication. 

The manner in which these compact, fine-grained rocks have 
been reduced along lines of shearing into fissile slates is most 
instructive. Thisis accompanied by the abundant production 
of sericite in the acid, and of chlorite in the basic rocks, while 
the phenocrysts and all original structures are obliterated. 
Amyegdules, where present, usually remain as flattened spots, 
either lighter or darker than the rock. Several suites of speci- 
mens have been collected to illustrate this process, but the 
account of its details must be reserved for a future paper. 

That the large area of fissile, pale green schists occurring 
between Pine Grove Furnace and Laurel Forge consists of 
sheared felsite may be seen from the following analysis, made 
for commercial purposes by A. 8. MceCreath. Thisrock, which 
is locally known as “soapstone,” is extensively used at Pine 
Grove Furnace in the manufacture of brick. Its alkalies were 
not determined. 


STKOD (i Seats Wy REI, ELE eee ae Oat 74:970 
PIRO ME GO meal RY et inl 13-860 
J ENEXO) Uh aah etek NE RCSA S AM ee og 9 ea ot a 2°700 
Ca@ serie einmreig tha PTA ek 0°220 
Vt Obs 53 eee eran Aa ASN ONS 1:230 
JANN ee M Versys = EPR eds FRE aan hig WSS Ae ? 
Tortie iy rie: ae apd aes sade 2:058 
A RCOh eee ke es meee UR eas 95°038 


6. Comparison with other regions.—The comparative rarity 
of very ancient volcanic rocks in America as compared with 
Great Britain* and other parts of Europe is doubtless due to 
their not having been recognized, rather than to their actual 
absence. The opinions entertained by Hunt of rocks like those 
of South Mountain have greatly retarded, in this country, the 
appreciation of their true character. Still they are well known 
on Lake Superior and in Missouri through the writings of 
Irvingt and E. Haworth;t Wadsworth$ and Diller| have 
described them in eastern Massachusetts, Shaler€{ in Maine, 
and the northern continuation of this same belt has been made 


%* Sir A. Geikie: Anniversary Address, Quart. Jour. Geol. Soc, vols. xlvii and 
xlviii, 1891-1892. 

+ Monographs U. §. Geol. Survey, v, 1883; and Bulletin, No. 62, 1890. 

¢ Am. Geologist, vol. i, p. 280, 1888, and Bull. Missouri Geol. Survey, No. 5. 

§ Bull. Mus. Compar. Zool Cambridge, vol. v, No. 13, p. 282. 

| Ibid., vol. vii, No. 2, 1881. 

§| This Journal (I1]), vol. xxxii, p. 40, 1886. Ann. Rep. U.S. Geol. Surv., vol. 
viii, p. 1043, 1889. 

AM. JOUR. SC1.—THIRD SERIES, VOL. XLIV, No. 264.—DEcEMBER, 1892, 


33 


496 Scientific Intelligence. 


known by the Canadian geologists, Bailey, Matthew and Ells, 
in New Brunswick.* Bell has also recently described similar 
rocks in the Sudbury region.t 

Similar areas are easily recognizable in Canada and Maine 
from the writings of Hunt, Jackson and Hitchcock, in spite of 
the fact that they are not properly interpreted. Volcanic 
rocks have not before been clearly identified in the Appalach- 
ians, but if attention is called to them they will doubtless be 
recognized at many other points. 


Petrographical Laboratory, 
Johns Hopkins University, Nov. 1, 1892. 


SCIENTIFIC INTELLIGENCE. 


I. CHEMISTRY AND PHYSICS. 


1. On the Temperature of Steam from Boiling Salt-solutions. 
Considerable diversity of opinion exists on the question of the 
temperature of the vapor arising from boiling salt-solutions. Cer- 
tain observers, as Faraday, Wiillner and Magnus, maintain 
that this temperature is the same as that of the solution, while 
others, as Rudberg and Miiller, hold the opinion that it is practi- 
cally the same as that arising from water, boiling under the same 
pressure. In order to settle the question Sakurar has made a 
series of experiments in which certain sources of error incident to 
previous methods of investigation were avoided. His apparatus 
consisted of a long necked flask containing the solution, through 
the stopper of which two thermometers passed, one with its bulb 
in the solution the other with its bulb in the vapor above it. The 
neck of this flask was surrounded with a jacket, into which vapor 
could be passed from a boiler, and which was connected with a 
condenser. A third thermometer indicated the temperature in 
the jacket. Through a tubulure in the side of the flask, steam 
was blown in order to supply sufficient vapor to maintain the tem- 
perature in the neck, the excess of vapor passing off through a tube 
in the stopper. The solution to be examined was placed in the 
flask without soiling the neck, the stopper was inserted, a solution 
of acetic acid boiling at a slightly lower temperature than the 
solution was placed in the boiler and made to boil, and the gas 
was lighted under the flask. When the solution was heated to 
boiling, steam was admitted through the lateral tubulure and the 
whole being in equilibrium, the temperature of the thermometer 
was read, With a dilute solution of calcium chloride, the tem- 
perature of the solution varied from 112°5° to 113°3°, that of the 
jacket from 110°8° to 111:9° and that of the vapor from 111°2° to 


* Ann. Rep. Can. Geol. Surv., 1877-8 DD, and 1879-80 D. 
+ Ibid., for 1889-90 F, 1891. 


Chemistry and Physics. 497 


113°3°; the difference between the temperature of the vapor and 
that of the solution, in eight experiments, being as much as one 
degree in a single case only. Solutions of potassium nitrate and 
of sodium nitrate gave similar results. “The experiments above 
described prove beyond any possible doubt,” says the author, 
“that the temperature of the steam escaping from a boiling salt- 
solution is exactly the same as that of the solution. This I be- 
lieve is the first occasion on which the above important fact has 
been experimentally established.”—., Chem. Soc., 1xi, 495, June, 
SoZ: GonbwB: 

2. On the Allotropism of Amorphous Carbon.—A graphitite 
has been investigated by Luzi, obtained from the chalk at Wun- 
siedel in the Fichtelgebirge, which was pronounced by both Fuchs 
and by Sandberger to be amorphous carbon, the latter consider- 
ing it identical with the graphitoid or schungite of Lauer and 
Inostranzeff. A similar graphitite, occurring at Storgard in Finn- 
land, has also been examined by Luzi. It occurs in the form of 
dark gray nodules which mark paper like graphite, have a con- 
choidal fracture but no cleavage. Its density is 2°255—-2°26 at 
17°5°, and on combustion in oxygen it leaves 0°67 per cent of a light 
yellow ash. The Wunsiedel mineral has a density of 2°207, and 
is also entirely amorphous. It is free from hydrogen and _nitro- 
gen, and on oxidation with potassium chlorate and nitric acid, 
gives, after five successive treatments, an orange-yellow sub- 
stance, becoming brown on drying and insoluble in water and 
nitric acid. On heating, it is decomposed with a hissing sound, and 
glows, leaving behind a black powder. Under the microscope it 
appears to consist of minute irregularly rounded plates, which are 
doubly refracting. On analysis it gave 57:99 per cent of carbon, 
1°93 per cent of hydrogen and 46-08 per cent of oxygen. Since 
ordinary amorphous carbon is completely oxidized by treatment 
with potassium chlorate and nitric acid, as is also schungite, and 
since graphite is converted into graphitic oxide by this treatment, 
the author considers this a new variety of amorphous carbon 
resembling graphite in the products of its oxidation. Indeed it 
appears to resemble closely graphitite produced in arc-light car- 
bons, the oxidation-product of which gave Berthelot C 51:95, 
H 1°55 and O 46°50. This product the author calls graphititic 
oxide.— Ber. Berl. Chem. Ges., xxv, 1378, April, 1892. G. F. B. 

3. On amorphous Boron.—Moissan has prepared the so-called 
amorphous boron by the various methods described and has ana- 
lyzed the products. By the method of Gay Lussac and Thenard, 
acting on boric oxide with potassium, using a copper tube, the 
product contained 44:1 per cent of boron. By acting on boric 
oxide with sodium in presence of sodium chloride, the method of 
Deville and Wohler, a product containing 62°50 per cent of boron 
was obtained. By acting on potassium borofluoride with potas- 
sium, method of Berzelius, the product contained 51°15 of boron. 
On extracting the second product with boiling hydrochloric acid, 
the quantity of boron was raised to 71°97 per cent; extraction 


498 Scientific Intelligence. 


with water lowering it to 32°38 per cent. In consequence the 
author first attempted to prepare boron electrolytically. When 
a current of 35 amperes is passed through boric oxide mixed with 
one fifth of its mass of sodium borate and heated to 1200°, boron 
is set free but at once burns to oxide. He then tried reduction by 
means of magnesium, mixing 70 grams of finely powdered mag- 
nesium with 210 grams of recently fused boric oxide, and heating 
the mixture to bright redness ina clay crucible. After the action 
was over, the mass was treated with water acidulated with hydro- 
chloric acid, then with boiling strong hydrochloric acid, then with 
alcoholic potash and finally with hydrofluoric acid. The product 
was a light maroon powder, containing 94 or 95 per cent of 
boron. If this be fused with 50 times its weight of boric oxide 
and again treated with magnesium a product is obtained contain- 
ing 98°3 per cent of boron. And if the ieduction be effected in a 
crucible brasqued with titanic oxide and carbon, the percentage 
of boron may reach 99:2.—C. #&., exiv, 319, 392; J. Chem. Soce., 
Ixii, 681, 682, June, 1892. G. F. B. 

4, On the Atomic Mass of Boron.—ABRAHALL has determined 
in Dixon’s laboratory the atomic mass of boron by titrating boron 
bromide by means of silver nitrate. The mean of five accordant 
determinations gave 10°825.—J. Chem. Soc., 1xi, 650, Aug., 1892. 

G. F. B. 

5. Absorption power of metals for the Energy of Electrical 
waves.—Hertz concluded from his experiments that the production 
of resonance and the period of oscillation in resonators are not 
affected by the specific resistance or the magnetic properties of the 
secondary conductor. BsERKNEs of the University of Christiana 
has examined this subject using an electrometer and finds that cop- 
per, brass, german silver, platinum, nickel and iron show differ- 
ent absorptive powers. The rate of absor ption increases with the 
resistance and the magnetization of the metal. Iron and nickel 
showed a marked damping effect. Their magnetization however 
could be reversed one hundred million times per second. Byjernkes 
makes no reference to earlier papers of John Trowbridge and also 
of Professor Thomson of Cambridge, England, on this subject. 
Ann. der Physik und Chemie, 1892, No. 9, pp- 69-76. sp a 

6. Electrical Oscillations.—M. Zuanxver exhibits to a large 
audience Hertz’s oscillations by placing the conducting rods in 
the focal line of a concave mirror. ‘These rods are connected with 
a Geissler tube within which the ends are placed very close to- 
gether so that a general luminosity-is produced inside the tube. 
The effects are augmented by a species of relay. On either side 
of the terminals of the resonator are two other terminals from a 
circuit of 600 Planté cells of small size, which are regulated so 
that the current is just able to pass between the terminals. When 
the resonator responds to the electric oscillations the discharge 
from the cells is augmented. It is also possible to work with 
another Ruhmkorff coil instead of with the secondary battery. 
Ann. der Physik und Chemie, 1892, No. 9, pp. 77-92. Jae 


Geology and Natural History. 499 


7. On Joints in Magnetic Circuits.—Prof. Ewi1xe shows the 
great effect of joints in reduciog the residual magnetism of iron. 
The division of a ring 30° long into two half rings abutting 
against each other with the smoothest possible joints has the effect 
of reducing the residual magnetism from 9,000 to 6,000. ‘A sim- 
ilar reduction occurs in magnetic tests of bars when these are 
made to form part of a magnetic circuit by the addition of a ma- 
rine iron yoke.”— Phil. Mag., Oct., 1892, pp. 320-326. BAN 

8. Measurement of high temperatures.—Lupwic Horisorn and 
Witty WIEN discuss the electrical methods of measuring high tem- 
peratures and give results obtained by the use of a thermo-ele- 
ment of platinum and platinum-rhodium. ‘This method appears 
to be preferable to Siemens’s method of observing change in elec- 
trical resistance. The authors obtain concordant results for the 
melting point of gold, silver and copper.—Ann. der Physik und 
Chemie, 1892, No. 9, pp. 107-134. Js Ts 

9. Color Photography.—LiremMann by the aid of a very sensi- 
tive bromide of silver albumen plate, made orthochromatic by a 
solution of azalin and cyanine has succeeded in photographing the 
solar spectrum. Also a colored church window, a parrot, and 
other colored objects. The time of exposure with sunlight and 
the electric light varied from five to ten minutes. With diffuse 
light an exposure of several hours was necessary.— Comptes 
Kendus, cxiv, p. 961, 962, 1892. Bf 

10. Electrical Resistance of Metals at Low Temperatures.—Prof. 
Dewar and Prof. Fiemine have studied the electrical resistance 
of metals at the temperature of boiling oxygen, —197° C., and 
find an enormous decrease in the specific resistance of perfectly 
pure metals. Pure iron at —197° C. has z's of its resist- 
ance at 100° C. and pure copper ;4. The smallest impurity 
affects the results to a remarkable degree. A carbon filament 
such as is used in an incandescent lamp continually increased in 
resistance as the temperature was lowered. Carbon thus acts 
just the reverse of metals. Iron and nickel change most. Pure 
iron at the temperature of boiling oxygen, —197° C., conducts 
better than electrolytic copper at ordinary temperatures. — Phil. 
May., Oct., 1892, pp. 326-337. Sig A 


Il. GroLtocy anp NATURAL History. 


1. Les Régions Invisibles du Globe et des Espaces célestes : 
Eaux Souterraines, Tremblements de Terre, Météorites ; par A. 
Davupree, Membre del’ Institut. 240 pp. 8vo. 1892. —This volume 
is one of the series entitled ‘‘Bibliotheque Scientifique Interna- 
tionale,” published at Paris under the direction of Em. Alglave. 
Prof. Daubrée has here brought together some of his very valu- 
able papers illustrating geological principles by experimental re- 
searches. The papers included are the tollowing: I. The work 
of subterranean waters at the present time; II. The part they 
have taken as mineralizers during geological time; III. Earth- 


500 Seientijic Intelligence. 


quakes; IV. The geological work of subterranean gases; V. 
Meteorites, and the constitution of the globe. It is greatly to the 
advantage of the science that Prof. Daubrée has made his import- 
ant memoirs so conveniently accessible to those interested in the 
subject. This second edition contains several new figures. 

2. The Pleistocene History of Northeastern Iowa; by W. J. 
McGEE; pages 189 to 577 of the eleventh annual report of the 
director of the U. 8. Geological Survey for 1889-90. A notice of 
this very complete memoir on northeastern Iowa is deferred to 
another number. 

3. Geological Survey of Iowa.—A bill for a new geological 
survey of lowa passed the legislature of the State last winter. 
The appointments made for the Survey are Prof. 8. Calvin, 
Geologist, Charles R. Keyes, Assistant Geologist, and G. E. 
Patrick, Chemist. 

4. Tiefencontacte an den intrusiven Diabasen von New Jersey. 
A, ANDREAE and A. Osann. (Verhandlungen des Naturhist.- 
Med. Vereins zu Heidelberg).—The locality which was personally 
studied by the writers is that at Jersey City and the diabase that 
of the well known Palisades. The contact of this diabase with 
the Newark shales is remarkable in that in extent and character 
it resembles that of the coarse granular abyssal rocks and not the 
ordinary diabase contact. ‘The shales and arkose are completely 
changed to silicate hornstones, of which several varieties, one rich 
in tourmaline, are described. Thus the opinion that this diabase 
is intrusive receives strong support. Tis Vie 

5. Hleolite-Syenite of Litchfield, Me. and Red Hill, N. #. 
W.S. Baytry (Bull. Geolog. Soc. Am., vol. ili, pp. 231-252).— 
This paper gives a careful and minute petrographical and chemical 
study of two varieties of eleolite-syenite. The occurrence at 
Red Hill, N. H., had been previously described by Hawes in his 
Lithology of New Hampshire as a hornblende syenite, the nephe- 
lite having been overlooked. It consists of augite, hornblende, bio- 
tite, sodalite, nephelite, albite, orthoclase and sphene. The study 
was made on hand specimens and nothing is yet known of its 
geological occurrence and connections. The same may be said of 
the rock from Litchfield, search in the field not yet having shown 
the source of the bowlders in which it occurs. This latter is 
shown to be a new variety of eleolite syenite in that the alkali 
feldspar is chiefly albite, not orthoclase. Hence regarding the 
albite as the most acid of the plagioclases, by a strict interpreta- 
tion of Rosenbusch’s system of classification, the rock would fall 
among the theralites and to avoid this difficulty the author pro- 
poses to distinguish the variety by the name of ‘ Litchfieldite.” 
This shows the rather unfortunate result of attempting to classify 
rocks by set schemes as if they were species. It we accept the 
conception held by most petrographers that eleolite-syenite is 
an alkali magma—rich in alumina, moderate in amount of silica, 
poor in ferro-magnesia and lime—crystallizing into a granular 
rock composed essentially of nephelite and alkali feldspar with 


Geology and Natural History. 501 


one or more members of the amphibole, augite or mica families 

present, and not according to the crystallographic nature of the 

essential feldspar, the name proposed seems hardly necessary. 
T'iVia Be 

6. The Gems and Precious Stones of North America ; by 
Groren KF, Kunz.—An Appendix to this fine work, making pages 
337-367, has recently been issued. It gives much interesting 
matter, supplementary to the main volume, chiefly that which 
mineralogical investigation has brought out in the past two years. 

7. Muciferous System of Laminariacee, by GuicNARD (An- 
nales des Sciences Naturelles, 15, 1).—This study proves that 
certain genera of Laminariaceew, such as Lessonia and Alaria, 
can comprise species which have no muciferous canals, while others 
possess them. We therefore must conclude that their presence 
or absence cannot offer any specific character. G. L. G. 

8. Researches on Multiple Buds, by W. Russet (Annales 
des Sciences Naturelles).—The principal conclusions which these 
researches have led the author to are: 

(1) Lateral buds can be produced at the expense of the con- 
stituent parts of the foliar axil, either at the expense of the stem 
alone, or more rarely, that of the leaf. In the inflorescence of the 
Linden, Cactacez, and so on, their appearance can take place upon 
the summit at the same time as that of the axillary leat. 

(2) Every bud has at the commencement a double growth,— 
a proper growth, or one peculiar to itself, and a growth in com- 
mon with the organs which have formed it. The latter is in gen- 
eral much more rapid than the former, at least at the qutset. 

(3) The majority of leafy buds, and numerous flower-buds, can 
send out branches at their base. 

(4) These buds are the origin of successive ramifications which 
accompany the bud of the first generation, and sometimes these 
possess no axillary leaves at all. 

(5) These successive ramifications, which are ordinarily desig- 
nated as accessory buds or multiple buds, behave at the outset 
just as axillary buds themselves. 

(6) The disposition of these buds always obeys the laws of 
phyllotaxy. 

(7) The basal ramifications have a well-defined biological réle. 
It is from. these that many thorns and tendrils are produced, or 
modifications of inflorescence. 

(8) In the majority of cases these buds remain in the state of 
dormant buds, and are the origin of distortions which appear 
under certain circumstances in woody plants. Sometimes upon 
annuals they play the role of hibernating buds, and permit the 
plant to grow from one year to another. They can develop in 
the same year that they form, or in the following year, coinci- 
dental with the bud of the first generation. 

(9) We can show experimentally that the formation of these 
buds can continue throughout the whole life of the plant. This 
is well illustrated by Convolvulus, for example. 


502 Scientific Intelligence. 


The principal results of these researches can be condensed into 
a single statement: the law of the unity of the axillary bud has 
absolutely no exception. G. L. G. 

9. Artificial intracellular Crystallization ; EK. Brtzune.—The 
author has shown conclusively that within the cell it is possible 
to produce artificial crystals of considerable size. His résumé, 
stated at considerable length by him, is condensed in the follow- 
ing shorter statement : 

(1) All these crystallizations can be produced by the simple 
means of placing living tissues in pure glycerine. This reagent 
produces an exosmosis more rapid than that of the crystallizable 
substance dissolved in the water. From this process the sap is 
carried to the point of saturation and must undergo an intracel- 
lular precipitation. 

(2) The most abundant principles which are contained in young 
plants which he has studied are asparagine, leucine, and neutral 
sulphate of potassium. The two amides crystallize in the cells 
simultaneously with the greatest facility. In Lupinus luteus, as- 
paragine, tyrosine, and sulphate of calcium are produced. The 
gypsum crystallizes in the tissues, for Cicer, xanthine and calcium 
sulphate. Xanthine has been hitherto unknown as a product of 
the normal activity of the plant. It crystallizes clearly in the 
cells, in very delicate filamentous forms. In Cucurbita pepo, as- 
paragine and potassium nitrate, can be very easily made to crys- 
tallize in all these cases. 

(3) The metamorphosis of protein and saline matters under 
these conditions is almost exactly like that which takes place in 
the ripening of a seed, so that we have really artificial aleurone 
grains formed, much as in a ripened seed. 

(4) What is the mechanism of the formation of these different 
products? Certain of the amides are produced from albuminoid 
_ matters by dilute acids or alkalies, as a consequence of the action 
of particular ferments, diastatic or peptonizing. So far as the 
mineral products, the nitrates and sulphates, are concerned, little 
can be said positively. The nitrates of germination, for example, 
are comparable with those salts of the same composition which 
result from bacterial fermentation of ammoniacal compounds, and 
the same remark applies to the sulphates of germination. G. L. G. 

10. On the Aeration of Solid Tissues ; HENr1 DEvaux.—(1) 
The internal atmosphere of all solid tissues contains a notable 
proportion of oxygen, in certain cases pretty nearly that which 
exists in pure air. 

(2) The proportion of carbonic acid is in general feeble. 

(3) The proportion of nitrogen is often different from that 
which exists in pure air, sometimes less, often more. 

(4) The total pressure of the internal atmosphere differs from 
that of the exterior air, sometimes positively, more often nega- 
tively, and its ratio is always inverse to the proportion of nitrogen. 

(5) We may consider tubers, tubercles, fleshy fruits, and most 
solid organs as formed of a mass very porous in its character, 


Geology and Natural History. 503 


which is enveloped by a thin and porous membrane, less per- 
meable than itself. Sometimes this has no normal pores, for in- 
stance, in the apple, the orange. 

(6) It is probable that a gas which traverses the envelope can 
penetrate to the deepest part of the tissue. 

(7) The gas passes through the external envelope of solid 
masses, sometimes in the free state, and sometimes dissolved. 

(8) The changes which are produced at the surface depend on 
the permeability and the porosity of the peridermic membrane. 

(9) Oxygen tends to enter especially by the pores, while car- 
bonie acid escapes from the whole surface of the membrane. 
There exists a veritable circulation of these gases, but the circu- 
lation is only partial in the majority of instances. 

(10) Humidity acts in a very variable manner on the composi- 
tion of the internal atmosphere, sometimes increasing permeabil- 
ity, sometimes diminishing it. 

(11) Slow or rapid drying diminishes permeability and causes 
a greater and greater accumulation of carbonic acid. 

(12) It is to these variations in the proportions of oxygen and 
carbonic acid in the internal atmosphere that we must attribute 
the different values of pressure in the internal atmosphere. 

(18) According as the total pressure is stronger or weaker in 
the internal atmosphere, there is produced across the superficial 
pores an inward or an outward current. This gaseous current is 
purely mechanical, and can be regarded as a third series of 
exchanges. 

(14) Nitrogen is passively held in this gaseous current. 

(15) When the gas acquires a constant difference of pressure, 
in spite of the constant sweeping hither and thither, we must 
believe that the current is produced in some other way than by 
diffusion. A constant circulation of nitrogen exists in the aérial 
parts of plants, but the circulation is purely passive. 

(16) Temperature increases or diminishes the intensity of res- 
piration, and this modifies the composition of the internal atmos- 

here. 

(17) Light acts wherever green matter exists, sometimes 
through chlorophylline assimilation, and sometimes by the with- 
drawal of water, thus influencing the permeability of the mem- 
branes. 

The mechanism of exchange can be summed up in the fol- 
lowing conclusion: Gaseous exchanges of all solid organs hitherto 
studied are produced in three different ways, which ordinarily co- 
exist, but which act with a variable intensity. These are, Effu- 
sion; Dialysis; and a purely mechanical passage of a gaseous 
current. 

Effusion. Diffusion of free gas across the pores of an envelope 
under the influence of differences of pressure proper to each gas. 

Dialysis. Diffusion of gas, dissolved, across the membrane 
under the same influence. 


504 Miscellaneous Intelligence. 


Gaseous current. General displacement of the total mass of 
the mixed gases across the pores of the envelope under the influ- 
ence of the difference of total pressure which exists between the: 
interior and the exterior. G. L. G. 

11. Bibliotheca Zoologica, I1.—This valuable and exhaustive 
work, under the editorship of Dr. O. Taschenberg, giving the 
titles of works and articles on Zoology which appeared between 
1861-1880, has reached its 10th Lieferung. This includes the 
last of the Mollusca and beginning of the Vertebrates, covering 
signatures 361 to 400, or pp. 2929 to 3248. 


III. MiscELLANEOUS SCIENTIFIC INTELLIGENCE. 


National Academy of Sciences.—At the meeting of the 
Nae Academy held in Baltimore, Nov. 1 to 4, 1892, the fol- 
lowing papers were presented : 


G. K. Gitpert: The Evolution of the Moon. 

T. C. MENDENHALL: On the Observations for Latitude at Rockville. Md. On 
the Latitude Observations at Honolulu. The Use of Planes and Knife-edges in 
Pendulums. 

THoMAS B. OSBORNE: Crystallized Vegetable Proteids. Proteids of the Flax- 
seed. 

H. A. Rowxianp: A Spectroscopic Analysis of the Rare Earths. <A Table of 
Standard Waye-lengths. On the Motion of a Sphere in a viscous Fluid. 

G. H. WinuraAms: Voleanie Rocks of South Mountain in Pennsylvania and 
Maryland. 

IrA REMSEN: On Some Curious Double Halides. Study of the Action of Light 
on acids in Solutions containing a Salt of Uranium. 

C. Barus: On Isothermals and Isometries of Viscosity. 

W. K. Brooks: Significance of the Follicle of Salpa. Biological Relations of 
the oldest Fossils. 

EK. D. Cope: On the Vertebrate Fauna of the Blanco Epoch. 

S. C. CHANDLER: On the Motion of the Earth’s Pole. 

C. S. Hastines: Recent Improvements in Astronomical Telescope. 

GEORGE K. Hate: Exhibition of Photographs illustrating new methods and 
results in Solar Physics. 

GEORGE K. Squier and FrRanK A. Wourr, JR.: Some effects of Magnetism on 
Chemical Action. 


Volume V of the Memoirs of the Academy, which has just 
appeared, is a large quarto of about 600 pages with many plates. 
The following are the papers it contains: On energy and vision 
loniss lee Langley ; ; Contributions to Meteorology by Elias Loomis; 
Report of studies of atmospheric Electricity by T. C. Mendenhall; 
Embryology and metamorphosis of the Macroura by W. K. 
Brooks and F. H. Herrick; Application of interference methods 
to astronomical measurements by A. A. Michelson. 


EN DHX NO WOW Nii XI: 


A 
Academy of Sciences, National, Balti- 
more meeting, 504. 
Alabama, Geol. survey, 1892, Smith, 78; 
427. 
Albirupean studies, Uhler, 333. 


Altitudes in the United States, diction- | 


ary of, Gannett, 262. 
Arkansas, Geol. survey, Penrose, 428. 
Arnold, H., Die Negativ-retouche, etc., 
256. 


Association, American, Rochester meet- | 


ing, 81; 337. 
British, Edinburgh meeting, 342. 


B 
Barker, G. F., chemical abstracts, 170, 
250, 418, 496; Physics, advanced | 


course, 426. 


Barlow, A. E., relations of the Lauren- 
tian and Huronian of Lake Huron, | 


236. 
Barus, C., 
on passing from sclid to liquid, 


change of heat conductivity 
1; 


electric conductivity of rock magmas, | 
thermal variation of viscosity | 


242; 
and electrolytic resistance, 255. 


Bayley, W. S., striated garnet from Buck- | 


field, Me. 79; eleeolite-syenite of Me. 
and N. H., 500. 

Bedell, F., effects of self-induction and 
distributed static capacity in a con- 
ductor, 389. 

Beecher, C., development of the Brachi- 
opoda, Pt. II, 133; 


fauna in Columbia Co., N. Y., 410. 


Bishop, 8. E, Kilauea in April, 1892, | 


207. 
Blowpipe Analysis, Landauer, 80. 
Botany— 
Acration of solid tissues, Devaux, 502. 
Intracellular crystallization, artificial, 
Belzung, 501. 
Laminariaceze, muciferous ne | 
Guignard, 501. 
Multiple buds, researches, Russell,501. 
Browning, P. E., 
from strontium, 459; 
strontium from calcium, 462. 
Burton, W. K., the great earthquake of | 
Japan, 1891, 80. 


lower Oriskany | 


| 


separation of ae 
separation of | 


| 


C 
CHEMICAL WORKS— 

Chemical Calculations, Whiteley, 73. 

Chemistry, Theoretical, Meyer, 255. 

Jahrbuch der Chemie, Meyer, 72. 

CHEMISTRY— 

Azoimide, inorganic synthesis, Wisli- 
cenus, 421. 

Barium separated from strontium by 
amyl alcohol, Browning, 459. 

Boron, amorphous, Moisson, 497. 

Boron, atomic mass, Abrahall, 498. 

Ceesium-mercuric halides, Wells, 221; 
crystallography, Penfield, 311. 

and rubidium chloraurates and 
bromaurates, Wells, Wheeler and 
Penfield, 157. 

Carbon, allotropism of amorphous, 

Luzi, 497. 

dioxide, industrial production of 
liquid, Troost, 421. 

new forms. Luzi, 251. 

Coal dust explosions, Thorpe, 250. 

gas flames, luminosity, Lewes,70. 

Hydrogen and oxygen, relative densi- 
ties, Rayleigh, 418. 

Hydroxylamine, free, de Bruyne, 253. 

Todates, alkaline, Wheeler and Pen- 
field, 123. 

Magnesium chloride separated from 
the chlorides of sodium and potas- 
sium, Riggs, 103. 

Metallic carbonyls, Mond, 422. 

Nitrates, iodometric determination of, 
Gooch and Gruener, 117 

Osmotic pressure, measurement, T'am- 
mann, 71. 

Oxidation of nitrogen by the spark, 
Lepel, 421. 

Oxygen and air, liquefied, properties, 
Dewar. 419. 

Peutahalides, alkali-metal, 42. 

Phenol, coefficient of molecular de- 
pression, Juillard and Curchod, 72. 

Potassium permanganate and sul- 
phuric acid, interaction, Gooch and 
Danner, 301. 

Quinite, Baeyer, 252. 

Rubidium determined by the spectro- 
scope, Gooch and Phinney, 392. 
Salt-solutions, temperature of steam 

from boiling, Sakurai, 496. 


* This Index contains the general heads BoTaNy, CHEMISTRY, GsOLOGY, MINERALS, 
OBITUARY, Rocks, and under each the titles of Articles referring thereto are mentioned. 


506 


CHEMISTRY — 
Silver and alkali-metals,double halides 
of, Wells and Wheeler, 155. 
chlorides, Lea, 444, 446. 
hemisulphate, Lea, 322. 
notes on, Lea. 444. | 
oxide, estimation and dehydration 
of, Lea, 249 
Strontium separated from calcium, 
Browning, 462. 
Clarke, F. W., constitution of ptilolite 
and mordenite, 101. 
Clarke, J. M., list of species of the 
Oriskany fauna N. Y., 411. | 
Claypole, Paleeaspis of. 428. | 
Color of compounds and their chemical 
constitution, Schiitze, 252 
of solutions of salts as affected by | 
the concentration of the ions, Line- 
barger, 416. 
photography, Lippmann, 75, 499; 
Vogel, 423. 
system, Rood, 263. 
Conwentz, von H , Untersuchungen tiber | 
fossile Holzer & Schwedens, 260. 
Crehore, A. C., effects of self-induction | 
and distributed static capacity in a | 
conductor, 389. | 
Cross, W., post-Laramie deposits of 
Colorado, 19 ; new occurrence of ptilo- 
_ lite, 96. 


D | 

Davi. J. T)., Jura-trias trap of New 
Haven region, 165. 

Danner, E. W., interaction of potassium | 
permanganate and sulphuric acid, 301. | 

Darton, N. H., fossils in the Archean | 
rocks of Central Virginia, 50. | 

Daubrée, Work on Experimental Geol- | 
ogy, 499. | 

Day, D. T., Mineral Resources of the U. | 
954303 

Delgado, J. F. N., chiastolite from Por- | 
tugal, 79. | 

Dewey, F. P.. catalogue of collections in 
Economic Geology in the U. 8. Mu- 
seum, 259. 

Diller, J. S., mica-peridotite from Ken- 
tucky, 286; geology of the Taylor- 
ville region, California, 330. 

Dumble, E. T., Geol. survey of Texas, 
427. | 


E 


Eakins, L. G., new occurrence of ptilo- | 


lite, 96. 
Earthquake, the great Japan, 


| Geological society of America, 


1891, | 


Milne and Burton, 80. 


INDEX. 


| Electrical conductivity of rock magmas, 


Barus and Iddings, 242. 
discharge, action on gases and yva- 
pors, Ludeking, 254. 
oscillations, Toepler, 423; Zehnder, 
498. 
resistance of allotropic silver, Over- 
beck, 424; of the human body, 
von Frey, 76; of metals, Dewar 
and Fleming, 499. 
waves, absorption power of metals 
for the energy of, 498. 
Electricity of waterfalls, Lenard, 423. 


| Electrification and cloud condensation, 


Aitken, 254. 
Electromagnetic and electrostatic units, 
ratio between, Abraham, 254. 


| Electrometer, capillary, Whitmore, 64. 


F 


| Ferry, E.S8., persistence of vision, 192. 
Fossil, see GEOLOGY. 


G 

‘Gannett, H., dictionary of altitudes in 
the United States, 262 

Geikie, A., history of voleanic action in 
the British Isles. 76. 

Genth, F. A., penfieldite, a new species, 
260; contributions to mineralogy, No. 
54, 381. 

Sle 
Rochester meeting, 333, 

|GEOLOGICAL REPORTS AND SURVEYS— 
Alabama, 1892, Smith, 78, 427. 
Arkansas, 1890, Branner, 332; 

rose, 428. 

Towa, 590. 

Kentucky, 1890, 1891, Procter, 78. 

New Jersey, 1891, Smock, 77. 

New York, Paleontology, vol. viii, 
Hall, 330. 

Texas, Dumble, 427. 

| GroLocy— 

Archean of Central Virginia, fossils 
from, Darton, 50. 

Artesian boring in Texas, Hill, 406. 

Artesian and underground waters in 
Texas, ete., Hill, 333. 

Brachiopoda, development, 
Beecher, 133. 

Cambrian rocks of Pennsylvania and 
Maryland, Walcott, 469; of Vir- 
ginia, etc,, Walcott, 52. 

Chiastolite in fossiliferous slates of 
Portugal, Delgado, 79. 

Claosaurus and Ceratosaurus, restora- 
tions, Marsh, 343. 

Coral Islands off New Guinea, up- 
raised, Macgregor, 256. 


Pen- 


eth ih, 


INDEX. 507 
GEOLOGY— GEOLOGY— 
Cretaceous of northwestern Montana,, Volcanic action in the British Isles, 
Wood, 401. history, Geikie, 76. 


Paleeontology of, on Staten Is., Hol- | 
Mieke 2595 | 
Cycadean remains, Capellini and | 
Solms- Laubach, 336. 
Devonian fossils, Whiteaves, 429. 
system of eastern Pennsylvania, 
Prosser, 210. 
Fauna at the base of the Burlington 
limestone in Missouri, Keyes, 447. 
Fossil flora of the Bozeman coal field, 
Knowlton, 334. 
plants in glaciated regions, Nath- 

orst, 336. ; 

Geology of the Taylorville region, 
California, Diller, 330. 

Glacial epoch, unity of, Wright, 351. 

pot-holes in California, Turner, 

453. 

Glaciation in the Finger-Lake region, 
N. Y., Lincoln, 290. 

Glaciers, periodic variations in, Forel, 
342. 

Gold deposit at Pine Hill, California, 
Lindgren, 92. 

Gulf of Mexico as a measure of isos- 
tasy, McGee, 177. 

Jura and Trias, Taylorville, California, 
Hyatt, 330. 

Jura-trias trap of New Haven region, 
Dana, 165. ; 
Kilauea in April, 1892, Bishop, 207. 
Laurentian and Huronian of Lake 
Huron, relations of, Barlow, 236. 
Lower Silurian lLamellibranchiata, 
new, Ulrich, 79. 

Mannington oil-field, White, 78. 

Mastodon Americanus, Cuvier, restor- 
ations, Marsh, 350. 

Mesozoicvertebrate fossils, Marsh, 171. 

Oriskany fauna in Columbia Co, N. 
Y., new lower, Beecher and Clarke, 
410, 411. 

Paleeaspis, Claypole, 428. 

Post-Laramie deposits of Colorado, 
Cross, 19. 

Petroleum, natural gas, ete. of west 
Kentucky, Orton, 78. 

Sharon. coal of N. KH. 
bowlder in, Orton, 62. 

Shear-zone in the Adirondacks, Kemp, 
109. 

Siliceous beds in the Hocene of New 
Zealand. Hinde and Holmes, 259. 
Sylloge fungorum fossilium, Meschi- 

nelhi, 335. 
Terraces in glaciated regions, origin, 


Ohio, quartz 


Parr, 59} 


rocks of South Mt., in Pennsyl- 

vania and Maryland, Williams, 482. 

Whetstones and novaculites of Ar- 
kansas, Griswold. 332. 

Gooch, Frank A., iodometric determina- 
tion of nitrates, 117; convenient forms 
of laboratory apparatus, 239; inter- 
action of potassium permanganate 
and sulphuric acid, 301; rubidium de- 
termined by the spectroscope, 392. 

Griswold. L. S., whetstones and novac- 
ulites of Arkansas, 332. 

Gruener, H. W., 10odometric determina- 
tion of nitrates, 117. 


H 


Hall, J., the genera of Paleozoic Bra- 
chiopoda, 330. 

Headden, W. P., alloys of tin and iron, 
464, 

Heat conductivity, change of, Barus, 1. 

Hill, R. T., artesian and underground 
waters in Texas, ete., 333; artesian 
boring in Texas, 406. 

Hollick, A., Paleeontology of the Creta- 
ceous on Staten Is., 259. 

Howell, E. E., Mt. Joy meteorite, 415. 

Hyatt, A.. Jura and Trias, Taylorville, 
California, 330. 


I 


Iddings, J. P., electric conductivity of 
rock magmas, 242; origin of igneous 
rocks, 257; eruptive rocks of Yellow- 
stone Nat. Park, 429. 

Incandescent lamps, 
Nichols, 277. 

Isostasy, Gulf of Mexico as measure of, 
McGee, 177. 


age-coating in, 


J 
Japan, the great earthquake, Milne and 
Burton, 80. 


K 
Kemp. J. F., great shear-zone in the 
Adirondacks, 109. 

Kentucky, Geol. survey, Procter, 78. 
Keyes, OC. R., fauna at the base of Bur- 
lington limestone in Missouri, 447. 
Knowlton, F. H., fossil flora of the 

Bozeman coal field, 334. 
Kunz, G. F., Gems and precious stones 
of North America, 501. 


508 INDEX. 
L MINERALS— 
x Danalite, W. Cheyenne Canon, 385; 
Laboratory apparatus, Gooch, 239. Gosnell 250, 2 


Landauer, J., Blowpipe Analysis, 80. 


Lea, M. Carey, estimation and dehydra- | 


tion of silver oxide, 249; silver hemi- 
sulphate, 322; notes on silver, 444; 
silver chlorides, 446. 

Lincoln, D. F., glaciation in the Finger- 
Lake region, N. Y., 290. 

Lindgren, W., gold deposit at Pine 
Hill, California, 92. 

Linebarger, C. H., relations between the 
surface tensions and chemical consti- 
tution of liquids, 83; 


salt solutions, 416. 


Ludeking, C., synthesis of crocoite and 


pheenicochroite, 57. 


M 


McGee, W. 
measure of isostasy, 177; Pleistocene 
history of northern Iowa, 500. 

Macgregor, W., upraised Coral Islands 
off New Guinea, 256. 

Magnetic circuits, joints, Ewing, 499. 


and earth current phenomena, Te- | 


lation between, Ellis, 424. 
field, mapped by photography, 
~ Thwing, 374. 


Marsh, O. C., Mesozoic vertebrate fos- | 


sils, 171; restorations of Claosaurus 
and Ceratosaurus. 343; restorations of 
Mastodon Americanus, Cuvier, 350. 
Mathematicians and Astronomers, Con- 
gress, 81. 
Mechanics, Theoretical, Spencer, 256. 


Meschinelhi, A., Sylloge fungorum fossil. | | 


ium, ete., 335. 
Meteoric iron, Kenton Co., Ky., Preston, 
163. 


Meteorite, Mt. Joy, Penn., Howell, 415. | 


Washington Co, Kansas, Preston, 
400. 

Meyer, L., Outlines of Theoretical Chem- | 
istry, 255. 

Meyer, R., Jahrbuch der Chemie, 72. 

Millar, C. C. H., Florida, South Carolina 
and Canada phosphates, 342. 

Milne, J., great earthquake of Japan, 
1891, 80. 

Mineral resources of the U. 
430. 

MINERALS— 
Aguilarite, 381. 
Basilite, Sweden, 261. 
Crocoite, synthesis, 57. Cyrtolite, Col- 

orado, 387. 


concentration | 
of the ions as affecting the color of | 


J., Gulf of Mexico as a/| 


S., Day, | 


Fuchsite, Habersham Co., Ga., 388. 


| Garnet, Buckfield, Me., 79. Graphi- 
tite, 497. 
Herderite, Hebron, Me., 114. 
Lepidolite, Japan, 387. Léllingite, 
North Carolina, 384. 
Masrite, Egypt, 261. Metacinnabar- 


ite, Orange Co., Calif., 383. Mor- 
denite, constitution, 101. 

Penfieldite, 260. Pheenicochroite, syn- 

thesis, 57. Polybasite, Aspen, Col., 

15. Ptilolite, Custer Co., Col., 96 
101. 

Quartz, from the alteration of flesh- 
colored orthoclase, W. Cheyenne 
Canon, 385. 

Rutile, Colorado, 384. 

Sjogruvfite, Sweden, 262. 

Tennantite, Aspen, Col., 15 

Yttrium-calcium fluoride, 
386. 


Colorado, 


N 

| Natural Science, a monthly review, 170. 
| New Jersey, Geol. report, 1891, Smock, 
ie 

| Nichols, E. L., age-coating in incandes- 
cent lamps, 277, 


0 
OBITUARY— 
Rutherfurd, L. M., 82. 
Orton, E., quartz bowlder in the Sharon 
| coal of northwestern Ohio, 62; Petro- 
leum natural gas and asphalt rock of 
W. Kentucky, “78, 
| Osteology of Poébrotherium, Scott, 428. 


/ 


P 


Paléontologie végétale, Zeiller, 334. 
[een see GEOLOGY. 

| Pearce, S. H., polybasite and tennantite 
| from oe Col., 15. 

| Peloponnesus, geology of, part If, Phil- 
ippson, 79. 

| Penfield, 8. L., polybasite and tennantite 
from Aspen, Col, 15; crystallogra- 
phy of alkali-metal pentahalides, 42; 
herderite from Hebron, Me., 114; 
erystallographic notes on alkaline 
iodates, 123; crystallography of 
double halides of silver and alkali- 
metals, 155; crystallography of the 
cesium and rubidium chloraurates 


INDEX. 509 


and bromaurates, 157; crystallogra- | Smith, H. A., Geol. survey of Alabama, 
phy of ceesium-mercuric halides, 311; 1892, 78, 427. 


erystallographic notes, 381. | Smock, J. C., New Jersey Geol. report, 
Penrose, R. A. F., Geol. survey of Are HONG Hn 

kansas, 428. Specific inductive capacity of a dielectric, 
Philippson, A., geology of the Peloponne-| _‘Trouton and Lilly, 254. 

sus, part II, 79. Spencer, J., Theoretical Mechanics, 256. 
Phinney, J. I., rubidium determined by Stevens, ‘VY. LeC.. comparison of form- 

the spectroscope, 392. | __ ule for total radiation, 431. } 
Phosphates of Florida, South Carolina, Surface tension and chemical constitu- 

and Canada, Millar, 342. | tion of liquids, Linebarger, 83. 
Photography, color, Lippmann, 75, 499; 

Vogel, 423. T 


Physical and chemical phenomena at. Bey ! 
very low temperatures, Pictet, 253. | Tarr, R. S., origin of terraces in gla- 

Physics, advanced course, Barker, 426. | ciated regions, 99. 

Preston, H. L., meteorite, Washington | ‘Weubqeseas alate of the circumpolar region, 
Co., Kansas, 400; new meteorite from | 4300. : 
Kenton Co., Kentucky, 163. | Temperatures, measurments of high, Hol- 


born and Wien, 499. 
ey J. R., Kentucky, Geol. survey, Hiesray Cell SinbaTee Dumble, 427. 


Prosser, C. §., Devonian system of east- ore ea eee a elec- 
ia, 210. : es ciniin : 
Gua FenasyiNentia, Omg Thwing, C. B., photographic mapping 
R | the magnetic-field, 374. 

Radiation between 15° C and 100° C., aa oe Bee a Ceaee 5 
discussion of formule for, Stevens, | ~ 5,5 423. 498 Pay Waris 
43] fciliee epee i ; : : 
arama’ 5 : Turner, H. W., glacial pot-holes in Cali- 

Riggs, R. B., separation of magnesium z as ; : : 
chloride from the chlorides of sodium ONE, ee) Baves\ou Ate, bagels, Cele 


and potassium, 103. | fornia, 450. 
RocKks— | 
Diabase of N. Jersey, contact phe- | U 


nomena, Andres and Osann, 500. | Uhler, P. R., Albirnpean studies, 333. 
Eleeolite-syenite of Litchfield, Me., etc., | Ultra red rays, dispersion, Rubens, 76. 


Bayley, 500. | 
Eruptive rocks, Yellowstone Nat. | 
Park, Iddings; 429. Vv 
Granite of Durbach, Sauer, 429. _ Vapor density under diminished pres- 
Igneous rocks, origin, Iddings, 257. | __ Sure, Schall, 72. 
Lavas of Mt. Ingalls, California, Tur- | Vision, persistence of, Ferry, 192. 
ner, 455. | Volcanic, see GEOLOGY. 
Mica-peridotite, Kentucky, 286, © | 
Ottrelite in a metamorphic conglom- | W 


erate in the Green Mts. Whittle, Walcott, C. D., Cambrian rocks of Vir- 
270. | afte, ete., 52; Cambrian rocks of 
i ginia, ete, 52; 
Voleanic rocks of South Mt., Penn- | Pennsylvania and Maryland, 469. 


sylvania, G H. Williams, 482. Washington Philosophical Society, Bulle- 
Rood, O. N., color system, 263. Vaal ee We ih acer Oo hea 


Royal Society of London, Catalogue of Wells, H. L., alkali-metal pentahalides, 
scientific papers, 1874-1883, 170. | 


2 : 42; herderite from Hebron, Me., 114; 
Ruhmkorff coil, discharge, Moll, 73. double halides of silver aud the alkali- 
metals, 155; cesium and rubidium 
NS) chioraurates and bromaurates, 157; 
Sauer, A., granite of Durbach, 429. | ceesium-mercuric halides, 221. 

Scott, W. B., Osteology of Poébrotheri- | Wheeler, H. L., alkali-metal pentaha- 
um, 428. lides, 42; alkaline iodates, 123; 
Self-induction and static capacity in a double halides of silver and the alkali- 
conductor, Bedell and Crehore, 389. metals, 155; cesium and rubidium 

Silver, see CHEMISTRY. chloraurates and bromaurates, 157. 


510 


White, I. C., Mannington oil-field, 78. 

Whiteaves, J. F., Devonian fossils, 429. 

Whiteley, R. L., Chemical calculations, 
73 


Whitmore, J., method of increasing the 
range of capillary electrometer, 64. 
Whittle, C. L., an ottrelite-bearing phase 
of a metamorphic conglomerate in the 
Green Mts., 270. 

Williams, G. H., volcanic rocks of 
South Mt., in Pennsylvania and Mary- 
land, 482. 


INDEX. 


| Wiseonsin Academy of Sciences, trans- 
actions, 262. 

Wood, H., Cretaceous of northwestern 
Montana, 401. 

Wright, G. F., unity of the glacial epoch, 
361. 


Z 
Zeiller, R., Paléontologie végétale, 334. 
Zoologica, Bibliotheca, Taschenberg, 


504, 


° 


Am. Jour. Sci., Vol. XLIV, 1892. Plate |. 
NEPIONIC. NEALOGIC. EPHEBOLIC. 
1 2 a3 

< 

=! 

= 

om 

& 

fam] 

aH 

aI 

6 

a 

isl 

< 

f 8 

3 

7, 


10 11 


PROTREMATA. 


12 


TELOTREMATA. 


Am. Jour. Sci., Vol. XLIV, 1892. 


Plate Il. 


St) 


CLAOSAURUS ANNECTENS, Marsh. 


Cretaceous. 


Am. Jour. Sci., Vol. XLIV, 1892. Plate III. 


1. CLAOSAURUS. 2. CIMOLOPTERYX. 3. PALmoscrincus. 4-6. AUBLYSOoDON. Cretaceous. 


Am. Jour. 


Sci., Vol 


. XLIV, 1892. 


Plate 


V. 


STEGOSAURUS UNGULATUS, Marsh. 


Jurassic. 


Am. Jour. Sci., Vol. XLIV, 1892. Plate V. 


| 


1. LAOSAURUS. 2 and 3. CAMPTOSAURUS. Jurassic. 


Plate VI. 


XLIV, 1892. 


Sci., Vol. 


Am. Jour. 


_ Restoration of CLAOSAURUS ANNECTENS, Marsh. 


. One-fortieth natural size, 


x ei TPC eptticiccnccce 


Plate VII. 


Am. Jour. Sci., Vol. XLIV, 1892. 


Restoration of CERATOSAURUS NASICORNIS, Marsh. One-thirtieth natural size. 


DNs 


S75 


ya 
SE 
SO 


Am. Jour. Sci., Vol. XLIV, 1892. 


Plate VIII. 


‘IOLAND ‘SONVOINAWY NOGOISVJL JO UOTeAO\SEXT 


‘ezIS jeinqeu puooes-Aqa1Y OO 


Plate IX. 


Vol. XLIV, 1892. 


ie 


Am. Jour. Sc 


“BIUIUJI[RBO ‘WOURD) IOALY oUWUlExyoy, 


Ul soloy-40q 


Am. Jour. Sci., Vol. XLIV, 1892. Plate X. 


South MountTAIn RHYOLITES. 


1.—Lithophysae, Raccoon Creek. 2.— Flowstructure, Raccoon Creek, 
3.—Spherulites, North of Tom’s Creek. 
(All reduced about one-half.) 


as 


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NS 


CONTENTS. 


Arr. LV.—Experimental Compar ‘ison of Formule for T 
Radiation between 15° C. and 110° C.; by W. Lea 
SSIDEV ENS) S22 oes ee ie ee we ie 3 = niet ee 

LVI.—Notes on Silver; by M. C. Lea ... 44 

LVII.—Notes on Silver Chlorides; by M. C. Lea 25a 

- LVIUL—Remarkable Fauna at ie Base of the Burlington — 

~ Limestone in Northeastern Missouri; by C. R. Kryzs- 

LIX.—Glacial Pot-holes in California ; by H. W. Turner 
(With Plate IX)..5..02.0 

LX.—Lavas of Mount Ingalls, California; by H. W. Turner - 

LXI.—Method for the Quantitative Se snes of Barium — 
from Strontium by the action of Amyl Alcohol on the 
Bromides.; by P. EK. Brownine_:-...2- 2.2222 ee ¢ 

LXII.—Note on the method for the Quantitative Soper ation 
of Strontium from Calcium by the action of Amyl Alco- eet 
hol on the Nitrates; by P. E. Brownine ---.----_--- 462 

LXII.—Study of the Ronmation of the Alloys of Tin and bese 
Iron with descriptions of some new Alloys; by W. P.  — 
HBADDEN =.) J ee - 464 

LXIV.—Notes on the Cambrian Rocks of Pennsylvania and 
Maryland from the Susquehanna to the Potomac; by  __ 

‘ CAD WALcorrte = Woo RSE ee or = 

LXV.—Volcanic Rocks. of South Motwitain in Pennsylvania 
and Maryland; by G. H. Witi1ams. Oe Plate X)= 482 | 


SCIENTIFIC INTELLIGENCE. 


Chemistry and Physics—Temperature of Steam from Boiling Salt- eres 
SakvRAI, 496.—Allotropism of Amorphous Carbon, Luzi: Amorphous Boron, — 
Moissan, 497.—Atomic Mass of Boron, ABRAHALL: Absorption power of 
metals for the Energy of Electrical waves, BsERKNES: Electrical Oscillations, © 
M. ZEHNDER, 498.—Joints in Magnetic Circuits, Ewmnc: Measurement of high 
temperatures, HOLBORN and Wien: Color Photography, LIPPMANN: Electrical 
Resistance of Metals Zz Low EPHISEDIISE SS ee and FLEMING, 499, 5 


sleataee -Kaux Saitenaines Tremblements de Terre. Météorites, A. DAUB E, 
499. SUC History of, Northeastern lowa, W. J. es Be 


NE Ee Wess: BAYLEY, 500. Cocaine ead Precious Stones of ‘North Ameri ( 
F. Kuyz: Muciferous System of Laminariacee,; GUIGNARD: 
Multiple Buds, W. Russet, 501.—Artificial intracellular Gryatallaegeees 
BELZUNG: Aeration of Solid Tissues, H. Devaux, 502.—Bibliotheca Es 
IT, 504. 


Miscellaneous Scientific Inielligence—National Academy of ce pe 
InpeEx to Vol. XLIV, 505. 


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