Otc th A Dg She theta tng ete Dm tien tones NS ee See Sw ee a al etal Retna ette etn inner a tn Pa Be Mann iy Ri Bes Pe Hi gt hs Te Ni jin Fim tag” tours in at ae hal at yt gn, Pc tnar # Mn ge eng Aaah the Ronit tee Attn Ma! er mH al | am a Pn tn, Oe ee kes Rte ea te Bee ee tn 72 wet Mae ele Oe ee Rint _ ae R ote Sas, t Ie le a Reh ee A at nn etna yn Me ha a ain am po Mes me ee ee Set ee et Tne Ricl hate Re Me ge Re tt A RT ~~ Pinte Reh teen heii me bee ton! ~~ Som eam ee ee ee ee Seer TR te oe Mg one Ae i Ol Se Pls AB Hw Ps ee. Meet. 11% nhs Batata i ’ asia ane ¢ = im Ae me at Ne a a en in nie Me ntl = heist hr aga Rach sh Pi ath Vin AA IN ha As naan yc Ne aN BME hy lM Ra Ala MAPA Aten MPs SIAN Se ae alk eee i “ibe Ta Bone ane CER ee eR Te Me Nein My tet ht! BRIN GDA ge Ras Ars, ethan Ae iM a Moar Pe et te ttre al Nettintealtaalh) 7. en'heih soe rey = 8 Mea the NaN Re RI one eee iain Rh Nt Thee Whe He a a NTS ate ee Se eT ayn rte es et le he Ra at Rt eS ML Be Ate aw a AM RO AM MR AAs RRR AS AAT ol TT A ths AAPM RIN, Anita Hel thd, Ms Tatham WA Naat aM Path teh nc Aan Nath MeN Neha Poe oe MN ag Ra Matt he tr Ra behath 9 Se irapiperte- terete Ga nts Aarts aGinny Wav ad Pe re ireaaete es an an Neg, Mtg Tia al nt iy Mie a a Rl in in Nee tae eli Re eM BLN ley Aa tinine nen he Mn Mobeni M dpe T a ton 4 7 \ Anan AaR Ratan Balha 8 oer Eee ae ete oe Se nm Mette, te Me Phage Maa ty Np A I tit Bn gn? Sanh eal eS MI OF eA A te Ree A ety ete Te Me it at tbe ete He oe. Me Re A ane ee itt nine eR ee EN. ee ite dena y-ar- arr re me te Tce RR Re Te OA Ne PL BT lie TR 4 et SR te I AR Nia A Ne 8s inte eG OT aN bMS Mrmr AM eB Mey MH * ie : =e revs oF nee —_ ee Cd eA oe. Nae age Re het lt lita hm Big arte, etal te te eet ate Be Rete a Fak Ae Te VR at. Be hal PN RM nthe Aantal: Whine ee St et ees Ao ae 6 . i i ii ae ae tg whe tec tele Sahn Paes taint Ree ToT Ret sour a te a ete het = af Ne anne tg te a et i Nt iI elegy Sh te eh i alle ye ek rete Re FM a lee Ee AP alls MM At hig Nt a ee ee ee ee “ ea 5 -% _ Mee thy he ey owe NTR he ASA ae tne A Ae he he a PN ANNA Nad lente ate i MR AT N ey Mem tent ANA Ae Sone. LN RS IM NI ce A ANS POM APRs Borin We eaten Ba Siam ty ee ee ee ee ee aaa ne Pete eee A ER We el rane ear ae er ie ro 1s eee aera ere ose tar 0 wre a erate ed ET, re Ee eT cn alltenatiiy’ tetaity Oar ear ieie Nay RR I Fe 8 et te GR SM, OS TQ AAR SPs RU AI A LA AR eh TL Te atten An te Rete Retention nM * i A ct he hp os Ad eiglia ee tat Ma NM AAP Minden Ry A a ns mente Rate Ne NAS ondaeteaie ert rR aire eaparargr ter w- areas ak eae Pant eerie wire ERE ty ao ae ec = egg Pe as Magn Ti NA Ae tag MMe atte IN BT raya CT TI ANI A RRR Raheny bit th tok tot Nite Re 9 ihe, Friern Sy < eerie Me eat = a te ee Ree th er Rice eth tg we ett i et tat A taste, Mae Pg Fn «titty Poel. eh PIMA im yt ae Tt et a een ei Rn a eRe RR Rr ore ew Semen sek lhe tm ne a AKAN (the © Be en, hl ee OU te Ret nee a tN Re A A i ewe DA Ne Pea te, Ae CU +t Le, ER ree : rs Woot ao ht He eR acl Main Se et Se nh Meng Pe Sac ie BR Nil at a ee PR ti Ae ON ae le Ir Pid 0 Neen Me ite eal el He St Nel NeteiPee Mire ita, ha. Menthe a ttt Mn Mn ee Ane Steet be stand . facta hy aca fae” Moi Mee th hte wet RMR ihe a tne 8. Mah an. SalI RD Seer a ern eas RP NN igh SM ER ae Re RI we te Rett Veta ba etn RMR oR Reh woo Bann She eet Lik i ~ paren entirety tere Warr Sen ee ani eel ae aR Piece IN, uP a MIN ot Tee A RRM Aer ot tela Pn Mat mb lg Mette A a els a tReet Neth Martel, ih ait rtttn, Nfs Nees irae ep on ee Se A re esas me ste masta eR NT aA A TTI he ALM A bg Re re er eT ee bitte Se Reeth = Boating Bo 6 Main Ae ate ae, = tuPa ine! . ee Raat ee te titties Nalecet te tey Manta Bal? tain ety Sct ELE I Ne Se RIN HT Me MiG nA Lip Metre Moat Frat atte Ra 9 es bea RS the tet ARS ea mpeteterterire Sian eae tae ah Re Ngee te ie Ge Re ee . ee, ie ee ea i Pa Toain He Len Net ee At whe Tree ee a ee Pea ds Mes We HM ys the ite — Ma Te he a. MR et = Rey a . iste © a Hag A MMe AR POR AARC A Meh OM Ne AMEN A an aly hn = A et NRL Tl eR I te ale Vink eM bs ee - te et Nee ee eS Lana ee we ten . Re a i ei Re Mae ye 7 he Ree a ~~ a tM ae al, Ae MAR, Pot ey Nee Me te a er it i ee SR day Be A ls tN a RM 8 ele | Pees ESS =a . - ie teeth LL me Ae ae An be eh rE ARH tote mh. Tete sr . te te Be et. TeV Paha en DS eee rem". a eee oe tS YS wih Ml a ee eb 7 = ear ae aera nee © ae ee SA WY ee ee RR TE me ee teem tt He ty RAS Ms SF ae em Ae Se Re I ee ee ee A At tt OR rl ete Bee ae AS Ee RRR Ma Manatee SAT ite 8 nena Ae oer Sam ol 5 ee ee ee - _-~ sbideatltietin PAP? =m - ath i gp A ane ee, Sell eee oe tere Me Vee 8 amt 4 hy ne ne Se ee ea ‘oe - ; = a : cs Pyare en 37 = vie, wi ad er a ete RA ds, ee ee ee le allt ru%-« _/- ~~ A te A eR 4. WA ek ~~ ee es —~ D “ a Bix Natealn® Be oe mb —% > a* ae a os & PR tt! ko, %.% "> S- 2 er Rem, Rea, i Me Le ~ipgtamatr toe a . RN I = rt ok ee enh PR a tab thee SS» AES Parehttrt tas ete ee ee et Me A octet wat, ag Rte a Se eta MMI Yo Teer te MMA tae eds, Math hata Me ene Ry RM _ er a ~- Rie Met: Neh ten nad tes ey om . ~ othe , ~~ - the ee ee I ares eS + eT ie ted ee ee 2 eee id . "ny ee ee eee ee Ae Ae ne en ia — _ Pe AN ent an eI Ae Neen on ho — + Het eM - et eee we oe Cree so, eee a 4 mt ete MALS 9 wee ee te RE ee er eS Reon ie eon See Se aa Ro Aah 92%. Red A- SO OM OA n | wn ap atan s. baat rink aeslp te dices oibamnalcah 7 Ae = tah ans ie Ay eT MA ee tt Sea tee as eS et wn a ee 3 ue Palich. * eet Se en a Coe ae - ra Sh os 7 a4 uA ae be He Ae Oe > ~~ i Ry mete ee ee ee Sem Ae wen Oe ee ee ER Ps ee —~ Si. “pte Nalin Me ey. Pi IRL Rac nls Ne mrerigtest * iv WTA : et, Bt ret sah te eet ae pcaccunhoes S nawibae Mihai he a ree aa ue ant d he My Ry a PN m+ = 5 why we Ce se “. ee et a te mm a Le ee i SS Rel See Mi tb tak tet uns arb Amy Re Aleta Be —_, pry yer a-r riveree ~ oa a Ante TN NY ne yn er ae a. ~. a ye eR RA ak ee s - ian 2 eA Waa Ae OG Mate ee Se ee ee x A Lata no airy era eee mb ae Wee Oa eee CooL. ara eoee mae a, a yt 8d, ute Were ee SO 7 te OS ee . on am. = ements ~*~ Be me” oan “ Amy r a Se et elt Sei n Rer Se elie * Bas es eta a \ Pet = ee Netty 1, ye 7 n ~ i 7 a ee LAL ARRAA NUR me ee oe ee eS oe ee “Ae ee 8 NE nie het ee ee e Pata Fe AD LAE = I ote et Nal yee ‘aie a Pag n = Re eh a Lm a. “te ‘ ge A Se ew Se a> . ee sam, as ene ea ee a men ‘ = i kee ™~ 7 Lop : dt ~ ++ - me . Sree ae ate . AA, SH scaeien ak ; et ay ere ee a ’ ~~ . eds & - ars “ - . n al hae * al? . Z to - ~ “ ~ ~ s 5 - - os . : Ot eT Hake “~~ - ne a 7 La ere 7 - now os . « 1 ne wer m carreras Rhee SA 58 ee ee eS fy o a . - - a . A al | A 7 - - 7 7 : \ _- 440 " - as —* = oS Ree = Ae . a « ; a “ -% ~ - 7 * ~ io ~ th te aed - - s - ie r - —— -“- “ * 7 7 o - 7 : peer cate ie = - - : ~ : { - owin e i‘ - Ae 7 = 7 a - = a7 “. ov a — ole aN ~ % . . . > = = 7 : Pre ; * = - * = = » % * ~ a+ . RID “ee - 7 - a a i ar ~ ~ * ease . x mane’ me “ - nme : = mi - a Sore _—.~ 7 7 by ¥ . = ot tes n ” - ° ~ x as % % a allie . 7 = isd = > : ~ ” - + ~ * ~m « bs ee ~ “ . a ee i : : = : ; ‘ ~ 7 , ae ” \ = * : ‘ 7 Z : x . , - - 2 : a 2. : : ~ x 2 rr eee : - rind = = ” ~ 7 : ’ . ~ * Ly - : * ~ ~ - » 7 - . 7 . ~s ‘ “ - ia : See ; : : L . - a ~ oR ’ Care i “ - Tne he ee Re ie HN as “ . _— : res 2 : ~ eh tet Pe ~*s ~ - os abe Be " rn . ay - : ~~ es : ; ‘ va ~e aes . ~ 1 male ir Ban me _— = : . f - . ~ 7 ; _ . - ig Pee = ta erm hnans eter PAA , : _ . a - take teat Ant nie + hale 7a dnt 4 hatin ee : ‘W Pure Se NYRI tig I a wet RE PA He Ry oe Pil Be Ret ine, a ee ant ig nn ee bret 4 : ey a a 4" 3 . ‘ #5 “a a be . = eee ref! 7 ac! reps ‘ee tim Oe Atle err Are nee A roe ee a coset ee aan a marta ree tp iy ne Sas ootes bs ss on, by e-em ad iy ction mrt kn the Soe pommel ahs Raga Seb pit itt se hanmet ce one ere er ye eee Pe eee ay weet . ~s rs : “-* :™ - ser = eR, oe = ee pee a way ey eae we eS ae a eer ik vere Nw ARGS 0 fe yl eed nasa einiall - ee ee We wae > OAD bhai ntnc8 Pree - . 3 ‘ . : - VTE 4s ee o7.8 eee ; ee ee PC eae PO Seed Deel a tet ah? : : ' ‘ ’ a a én r x > pO f D THE AMERICAN JOURNAL OF SCLENCE. Epirorn: EDWARD S. DANA. ASSOCIATE EDITORS Proressorss GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or Camsripce, Proressorss ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON anp H. E. GREGORY, or New Haven, Proressor GEORGE F. BARKER, or PuHtapEeLPeun, Proressor HENRY S. WILLIAMS, or Itwaca, Proressor JOSEPH S. AMES, or Battimore, Mr. J. S. DILLER, or Wasuineron. FOURTH SERIES VOL. XXVII—[WHOLE NUMBER, CLXXYVII.] WITH PLATES I-IV. NEW HAVEN, CONNECTICUT. bas ONS ke 20539 ; t peak or Ode te deni ee Se Pav we Sd Mielke OY ) Wish = 4 ‘ CPF ; i be n 2 WS 2 ete ge abut. fy “sh ute st 7s ‘ a. 2 ¢ bj 7 de Ny by 72 ERA Seaman. ia wat re R ae ry urd oa oe ¥ rm * ‘ ane 4 te) Ee a ea wail Rots) ee . ite OP, Vee Cink. ee Ware » 2h aa ° 3 Fi a eave & ~ ‘i Ne aha ae ] ig , ; Pt i Fe NE gee Se. Bete eM Cr ame a Wei * ; ; AN =e 6 vik yan He Bete PN ee eel 9 ,) asian ae nen at a ee Pa Kote Larne ant ah ‘ we ty i: Veal btw ee yf E Le ‘ ae ea ADP AN ee eee ae te) ") Re eag Cie THE TUTTLE, MOREHOUSE & TAYLOR COMPANY, NEW HAVEN. — CONTENTS TO VOLUME XXVIILI. ING Dery: (: Page Art. I—Diopside and its Relations to Calcium and Magne- sium Metasilicates ; by E. T. ALLEN and W. P. Wuire. With Optical Study; by F. E. Wericur and H. 8. Pee suns oo Waltmeetate, b)2 os oe See eee 1 II.—California Earthquake of 1906; by G. K. GiLBEeRT __-- 48 I1f.—Descriptions of Tertiary Insects; by T. D. A. Cocx- BRST noe Se eee pe se eu ac OS IV.—Electrolytic Estimation of Lead and of Manganese by the Use of the Filtering Crucible ; by F: A. Gooou and CDs Be LSEDY ETERS 2 Pe Ee me ce 59 V.—Specific Radio-Activity of Thorium and its Products; Seer co NSHINGAING > feeee ty Seka To eden 65 V1I.—Coronas with Mercury Light; by C. Barus__-.-._---- 73 SCIENTIFIC INTELLIGENCE. Chemistry and Physics — Attempt to Produce a Compound of Argon, FISCHER and Inrovict: Explosive Crystallization, Wrston, 82.—Constituents of Ytterbium, A. v. WELsBAcH: New Form of ‘‘ Tin Infection,” von Hass- Positive Rays, W. WiEN: Spectral Intensity of Canal Rays, J. Stark and W. STENBERG: Canal Rays, J. Stark: Potential Measurements in the dark Cathode Space, W. WrEstTPpHAL, 84.—EHlements of Physics, NicHoLs and FRANKLIN: Text-Book of Physics, 89. Geology—Publications of the United States Geological Survey, 86.—Canada Geological Survey: North Carolina Geological and Economic Survey, 87.—Report of the State Geologist of Vermont for 1907-8: Thirty- second Annual Report, Indiana Department of Geology, 88.—Illinois State Geological Survey, Year-Book for 1907: New Zealand Geolog- ical Survey: Report on the Eruptions of the Soufriére in St. Vincent in 1902, and on a Visit to Montagne Pelée in Martinique, T. ANDERSON and J. S. Fiert, 89. —Geology and Ore deposits of the Coeur d’ Alene District, Idaho, 90.—Geologie der Steinkohlenlager, DANNENBERG: Geology of Coal and Coal-mining, W. Gipson: Physical History of the Earth in Out- line, J. B. Baspitt: Triassic Ichthyosauria. with special reference to American Forms, J. C. Merriam, 91.—Fossil Vertebrates in the American Museum of Natural History, Part I—Fishes, L. Hussaxor, 92.—Conrad Fissure, B. Brown: Four-horned Pelycosaurian from. the Permian of Texas, W. D. MatrHew : Osteology of Blastomeryx and Phylogeny of the ‘American Cervide, W. D. MatTHEw: Rhinoceroses from the Oligocene and Miocene deposits of North Dakota and Montana, E. Doveuass, 93.— Fossil Horses from North Dakota and Montana, E. Doveiass : Some Oli- gocene Lizards, E.-DoucLass: Preliminary Notes on Some American Chalicotheres, O. A. PETERSON, 94. Botany and Zoology—Harvard Botanical Station in Cuba, 94.—Handbuch der Bliiten-biologie, P. Knuta : Convenient Clearing and Mounting Agent, 96.—Economic Zoology: Text-book of the Principles of Animal Histology, U. DAHLGREN and W. A. Kepner: Archiv. fiir Zellforschung, R. GoLp- scHMIDT: Ueber die Hibildung bei der Milbe Pediculopsis graminum, 97. Miscellaneous Scientific Intelligence—Artificial Daylight for Use with the Microscope, F. E. Wricut: Ion; A Journal of Electrotonics, Atomistics, lIonology, Radio-activity and Raumchemistry, 98.—Life and Letters of Herbert Spencer, D. Duncan, 99.—American Association for the Advance- ment of Science: Nature of Enzyme Action: Rivista di Scienza, 100. Obituary—O. W. Gispps: W. E. Ayrton, 100. lv CONTENTS. Num ber 1538: Page Art. Vii.—Revision of the Protostegide ; by G. R. WIELAND. EW:th Elates TEL ic 5 sre ae pees oe 101 VIiI.—Submarine Eruptions of 1831 and 1891 near Pantel- leria; by H.'S. WASHINGTON) -....22._2 22 2 131 1X.—Types of Permian Insects; by E. H. Setuarps._-.-_- 151 X.—Iodometric Estimation of Vanadic Acid, Chromic Acid and Iron in the Presence of One Another ; by G. Epear 174 XI.—Analysis and Chemical Composition of the Mineral Warwickite; by W. M. Brapuny -_:: 1: {2 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Question of Change in Total Weight of Chemically Reacting Substances, H. Lanpott: Volume of Radium Emanation, RUTHERFORD, 185.—New Method for Separating Tungstic and Silicic Oxides, Drracgz: Silicide of Uranium, Deracegz: New Periodic Func- tion of the Atomic Weight, V. Poscut, 186.—Velocity of Rontgen Rays ; also their Influence on the Brush Discharge, EH. Marx: Radiation of Uranium X, H. W. Scumipt: Influence of Self Induction on Spark Spectra, G. BeErnpT: Ionization of Gases by Spark and Arc, H. Rauscu, 187.—Investigations in Radiation, W. W. CoBLentz and P. G. NuttTine, 188. Geology—Twenty-ninth Annual Report United States Geological Survey, G. O. SmrtH, 188.—Geological Survey of New Jersey, H. B. KumMMeEL : Sketch of the Geography and Geology of the Himalaya Mountains and Tibet, S. G. Burrarp and H. H. Haypen, 189.—Gases in Rocks, R. T. CHAMBERLIN, 190. Botany and Zoology—Forest Flora of New South Wales, J. H. Maipen, 191 —Jaarboek van het Department van Langbouw in Niederlandsch- Indie, 1907: Origin of Vertebrates, W. H. Gasket. 192.—Ticks: a Monograph of the Ixodoidea, G. H. F. Nuttatut, C. Warsurton, W. F. Cooper, and L. E. Ropinson: Animal Romances, G. RensHaw: Essays on Evolution, E. B. Poutton, 193.—Parasitology, G. H. F. Nurauy and A. EK. Suiprey, 194. Miscellaneous Scientific Intelligence—New Goniometer Lamp, F. E. Wrieut, 194.—Containing Device for Salts-Used as Sources for Monochromatic Light, F. E. Wricut, 195.—Report of the Secretary of the Smithsonian Institution for the year ending June 30, 1908, 196. Obituary—G. W. Hoven, 196. CONTENTS. v Number [59. . e ° . . Page Arr. XII.—Recent Observations in Atmospheric Electricity ; Ryegcttel th Drrany sohe oe M eee er Ae es 197 XIII.—Iodyrite from Tonopah, Nevada, and Broken Hill, New South Wales ; by E. H. Kravs and C. W. Coox-_-. 210 XIV.— Deviation of Rays by Prisms; by H. 8S. Unter-_.--. 223 XV.—Heat of Oxidation of Tin, and second paper on the Heat of Combination of Acidic Oxides with Sodium Beutaesemnye W.. Ge MISTER 2.55.22 0:5. 5) eb enolase 229 XVI.—Neptunite Crystals from San Benito County, Cali- mene MOMINV eH GMORD! Soa) i 2 s242 lS LOL ose 235 XVII.—Gravimetric Determination of Silver as the Chro- mate ; by F. A. Goocu and R. 8. BoswortuH .__--_---- 241 XVII.—Doppler Effect in Positive Rays; by J. TRowpripGe 245 XIX.—New Armored Saurian from the Niobrara; by G. R. Pe TELAND = -:.. ge SAD ENS TE aie rc EN BAS EASE eg area eae Ooo 250 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—New Method of Forming Liquid Alloys of Sodium and Potassium, JAUBERT: Determination of Cerium and other Rare Earths in Rocks, DietRicu, 260.—Solubility of Metallic Gold in Hydrochloric Acid in the presence of Organic Substances, AWERKIEW: The Composi- tion of Matter, E. MuLprr, 261.—Introduction to the Rarer Elements, P. E. Brownine: Feste Lésungen und Isomorphism, G. Bruni: Produc- tion of Helium from Uranium, F. Soppy: Charge and Nature of the a-Particle, EK. RUTHERFORD and H. GEIGER: Amount of Water in a Cloud formed by Expansion, W. B. Morton, 262.—Permanent Magnetism of Copper, J. G. Gray and A. D. Ross: United States Magnetic Tables and Magnetic Charts for 1905, L. A. Bavrr, 263. Geology and Natural History—Fossilen Insekten und die Phylogenie der Rezenten Formen, A. HANpDLIRScH, 263.—Connecticut Geological and Natural History Survey, W. N. Ricr: Mississippi State Geological Sur- vey, A. F, Criper, 264.—Interpretation of Topographic Maps, R. D. SaLisBury and W. W. Atwoop: Zonal Belt Hypothesis, a New Explana- tion of the Causes of the Ice Age, J. T. WHEELER: Handbuch der Min- eralogie, C. Hintze: Chemische Krystallographie, P. Grotu, 265.—Notes of a Botanist on the Amazon and Andes, R. SprucE, 266. Miscelianeous Scientific Intelligence—Carnegie Institution of Washington. Year Book No. 7, 1908, 267.—Report of the Librarian of Congress and Report of the Superintendent of the Library Buildings and Grounds, H. Putnam: Harvard College Observatory, E. C. Pickrrine, 269.—Publica- tions of the Allegheny Observatory of the University of Pittsburgh : Washburn Observatory of the University of Wisconsin, G. C. COMSTOCK : Treatise on Spherical Astronomy, R. Batu: Bulletin of the Mount Weather Observatory, W. J. HumpHreys, 270.—National Antarctic Expe- dition, 1901-1904 : Chemical Constitution of the Proteins, R. H. ADERS PuiMMER, 271.—Standard Algebra, W. J. Mitne: Kraft, dkonomis the, technische und kulturgeschichtliche Studien titber die Machtentfaltung der Staaten, E. Reyer: International Congress of Applied Chemistry : The Science Year Book, 272. Obituary—H. G. SEELEY, 272. vl CONTENTS. Number 160. Page Art. XX.—Permeabilities and the Reluctivities, for very Wide Ranges of Excitation, of Normal Specimens of Compressed Steel, Bessemer Steel and Norway Tron Rods ; by B. O. PEIRCE ween ebient br 213 XXI.—Ice Movement and Erosion along the Southwestern Adirondacks ; by W. J. MitunR_— 2 __* eee 289 XXII.—Estimation of Vanadie and Arsenic Acids and of Vanadic and Antimonic Acids, in the Presence of One Another; by G. EpGAR.. 222-222 299 XXII.—Method for the lodometric Estimation of Silver — Based upon the Use of Potassium Chromate as a Pre- cipitant ; by F. A. Gooon and R. 8. Bosworr ----.-- 302 XXIV.—Brown Artesian Waters of Costilla County, Colo., their relations to Certain Deposits of Natron or Soda, and what they teach; by W. P. HeappEN._-.-_-. =.= 305 XXV.—Volumetric Determination of Small Amounts of Arsenic; by L: W. ANDREWs and HE. V. Warre-sseee 316 XXVI.—Preliminary Report on the Messina EKarthquake of |. December 28,.1908; by F. A. Pureur (222 Sea 321 XX VITI.—New Connecting Link in the Genesis of ee by C.J. MAURY... 2 52 Se ee eee 335 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Method for Calculating the Boiling-points of Metals, F. Krarrt and KNnocKEe: Some Properties of the Radium Hmana- tion, RUTHERFORD, 836.—Method for Preparing Hydrogen Phosphide, MaTIGNON and TRANNOY: The Theory of Valency, J. N. FrienD: Recent Advances in Organic Chemistry, A. W. StEwart. 337.—Michelson’s Ether Research, KE. Koni: Influence of Pressure upon Thermoelectric Force, H. Horie: Aluminum Cell as a Condenser, J. DE MopzELEWSKI: Changes in the Spectra of Gases submitted to the Magnetic Field, A. Durour: Die elektrischen EKigenschaften und die Bedeutung des Selens fiir die Elektro- technik, C. Rims, 838.—Physics for Secondary Schools, C. F. ADAmMs: Elements of Physics, G. A. HOADLEY, 339. Geology and Natural History—lowa Geological Survey Report for 1907, S. Catvin: Oklahoma Geological Survey, C. N. Gouutp, L. L. HutcHison and G. NELson, 339.—Glaciation of Uinta and Wasatch Mountains, W. W. ATwoop : Glacial Waters in Central New York, H. L. Farrcuitp: Ground Waters of Indio Region, California, W. C. MENDENHALL, 340.—Die Alpen im Hiszeitalter, A. Penck und E. Brickner: Geological Survey of Western Australia, A. G. Maittanp: Die Geologischen Grundlagen der Abstam- mungslehre, G. STEINMANN, 341.—Mineralien-Sammlungen, W. PRENDLER: Jadeite from Upper Burma, A. W. G. BLEEcK, 345.—Rubies from Upper Burma, A. W. G. BLEEcK: New Group of Manganates, L. L. FERmor : Die Bliitenflanzen Afrikas, F. THonner, 344.—Schwendeners Vorlesungen tiber mechanische Probleme der Botanik, HoLTeRMANN : Plant Study with Directions for Laboratory and Field Work, MrtEr, 340. Miscellaneous Scientific Intelligence—Carnegie Foundation for the Advance- ment of Teaching; Report of the President, H. S. PritcHett, and Treas- urer, T. M. CARNEGIE, 346.—Carnegie Institution of Washington, 347.— Report of the Superintendent of the Coast and Geodetic Survey, O. Hi. TITTMANN.: Principal Facts of the Earth’s Magnetism, 348. CONTENTS. Vil Number 161. Page Art. XX VIII.— Weathering and Erosion as Time Measures ; 3 bye LEVERETE. 262+ oe: PL ae URIS eg gee er regs 349 XXIX.—Chalk Formations of Northeast Texas; by C. H. oF PIRI OI 2a ee a Ae oe eG ae Oe ee Ce 369 XX X.—Devonian of Central Missouri; by D. K. Grecer-. 374 XX XI.—Volumetric and Gravimetric Estimation of Thal- lium in Alkaline Solution by Means of Potassium Ferricyanide; by P. E. Brownine and H. E. Patmer.-_ 379 XXXII. — Descriptions of Tertiary Insects, VI; by T. D. A. ce 2 STR IETRETL | oer Sy tS ei pee Vee 381 XX XIII.—Divided Lakes in Western Minnedota: ; by Rk. F. geri ie es Ss Si ie a bs fee ea as SES 388 XXXIV.—Heat of Formation of Titanium Dioxide, and third paper on the Heat of Combination of Acidic Oxides with Sedium Oxide; by W.'G. Mixrmer....-. 2.22.2. 393 XXXV.—Note on Cr ystal Form of Benitoite ; by C. PaLtacHE 398 XXX VI.-—-Alamosite, a new Lead Silicate from Mexico ; by Pee eeArscHH and W..W: MERWIN .2.2.-222- s2522. 552. 399 XXX VII.—Absence of Polarization in Artificial Fogs ; by oy En TEUS Sao eS Re ga Os She a eee eee 402 SCIENTIFIC INTELLIGENCE. Chemistry and Physics— Prussian Blue and Turnbull’s Blue, MULLER and STaniIscH: Chemistry of the Radio-active Elements, STROMHOLM and SvEDBERG, 403.—Hydrogen Silicides, LEBEav: Determination of Boron, Copaux and Boireau, 404.—Canal Rays, J. Stark and W. STEUBING : Zeeman Effect of Mercury Lines, P. Gmetin: Presence of Rays of High Penetrability in the Atmosphere, T. WuLF: Use of Radiometer for Observ- ing Small Pressures, J. Dressar, 405.—Wireless Telegraphy and Telephony Popularly Explained, W. W. Massiz and C. R. UNDERHILL: Introduction to the Science of Radio-activity, C. W. Rarrerty, 406. eee, y and Natural History—Publications of the Op Geological Survey, G. O. SmitH, 406.—Economic Geology of the Georgetown Quadrangle, Colorado, J. E. Spurr and G. H. Garrey, 408.—Geology of the Gold Fields of British Guiana, J. B. Harrison, 409.—Eruption of Vesuvius in . April, 1906, H. J. Jounston-Lavis: Essai sur la Constitution géologique de la Cuyane hollandaise (district occidental), H. Van CAPELLE: Text- - Book of Petrology, F. H. Hatcu, 410.—Classification of the Plutonic Rocks, F. H. Hatcu, 411. —Elements of Optical Mineralogy, WINCHELL: Geology of the Taylorsville Region, California, J. 5. DILLER, 412.—Explo- rations in Turkestan: Glacial Bowlders in the Blaini Formation, India, T. -H. Hotuanp: Guadalupian Fauna, G. H. Girry, 418.—Cambrian Sections of the Cordilleran Area, C. D. Watcotr: Mount Stephen Rocks and Fos- sils, C. D. Watcotr: Devonian Fishes of lowa, C. R. Eastman, 414.— ' Unterkiefer des Homo Heidelbergensis aus den Sanden von Mauer bei Heidelberg, O. ScHortTENnsAcK, 415.—Commercial Products of India, G. Warr, 417.—Forest Flora of New South Wales, J. H. Maren, 418. Miscellaneous Scientific Intelligence—National Academy of Sciences, 418.— Allgemeine Physiologie, M. VeRworn: Man in the Light of Evolution, J. M. Tyuer, 419.—Harvard College Observatory, E. C. PickrRinG : Pub- lications of the Allegheny Observatory of the University of Pittsburgh : Brooklyn Institute of Arts and Sciences, 420. Obituary—Dr. Persiror Frazer, 420. Vill CONTENTS. Number doz: ; Page Art. XXX VIII.—Quartz as a Geologic Thermometer ; by F,-E. Wrieut-and. E.'S, Larsen. /._..-., 222 eee XXXIX.—Precipitation of Copper Oxalate in Analysis ; by F.. A. Goocs and H. L. Warp 2) 2. an 448 XL.—Yakutat Coastal Plain of Alaska; A combined ter- restrial and marine Formation ; by E. BhackwELDER _ 459 XLI.—Pyrite Crystals from Bingham, Utah; by A. F, ROGERS |... 2s So ee ea Sn be ee XLII.—Composition of Stony Meteorites compared with that of Terrestrial Igneous Rocks, and considered with reference to their efficacy in World-Making; by G. P. Mamrrinn oo.) S22 aul 24 22 469 XLII.—Notes on the Family Pyramidellide; by K. J. Buss; Pa, D, 226s ee ee eee A475 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Liquid and Solid Radium Emanation, Gray and Ramsay: Gases Evolved by the Action of Cupric Chloride upon Steels, GouTaL, 485.—Radiation of Potassium Salts, KE. Hmnriot: Course of Qualitative Chemical Analysis of Inorganic Substances, O. F. Towsr, 486.—Suggested Method of Ascertaining the Existence of Chlorophyll on Planets, N. Umow: Condensation of the Radium Emanation, RUTHER- FORD: Electric Origin of Molecular Attraction, W. SUTHERLAND, 487,.— Physical Measurements, A. W. Durr and A. W. Ewe tu, 488. Geology and Natural History—Monograph on the Higher Crustacea of the Carboniferous Rocks of Scotland, B. N. PEacu, 488.—Fossils from the Silurian Formations of Tennessee, Indiana and Illinois, A. F. FoERSTE: Illinois State Geological Survey, C. W. Rourg, R. C. Purpy, A. N. TaL- Bot and I, O. BAKER: Wisconsin Geological, and Natural History Survey, iH, A. Birce and W. O. Horcuxiss: A new Locality of Diamonds in Africa, H. Kaiser, 489.—Interferenzerscheinungen im polarisirten Licht, H. HAUSWALDT: Complete Mineral Catalog, W. M. Foorr: Introduction to the Study of Rocks, L. FLercHrer: Determination of Rock-forming Min- erals, A. JOHANNSEN, 490.-—-Trees, A Handbook of Forest Botany for the Woodlands and the Laboratory, H. M. Warp: Mendel’s Principles of Heredity, W. Barrson, 491.—Catalogue of the Lepidoptera Phalenz in the British Museum, Vol. VII; Catalogue of the Noctuide, G. F. Hamp- son, 492. Miscelluneous Scientific Intelligence—Bulletin of the Mount Weather Obser- vatory, 492.—Field Columbian Museum, Chicago: Geographical Tables, ALBRECHT: An Astronomer’s Wife, A. HALL: Anciennes Meures; Mas- CART, 493, InDEX, 494. Cyrus Adler, a re eee f - | : op Librarian U. S. Nat. Museum. © VOL. XXVII. JANUARY, 1909. Established by BENJAMIN SILLIMAN in 1818. THE AMERICAN JOURNAL OF SCIENCE. Epirorn: EDWARD 8S. DANA. ASSOCIATE EDITORS % PROFESSORS GEORGE L. GOODALE, JOHN TROWBRIDGE, i W. G. FARLOW anp WM. M. DAVIS, or CamBrwwcz, PRoFESsoRS ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON anp H. E. GREGORY, or New Haven, Proressor GEORGE F. BARKER, or PHILADELPHIA, Proressor HENRY S. WILLIAMS, or ItHaca, Proressor JOSEPH S. AMES, or Battimore, Mr. J. S. DILLER, or Wasuincron. i — FOURTH SERIES 4 : No. 157--JANUARY, 1909. VOL. XX VII-—[WHOLE NUMBER, CLXXVII_] WITH PLATE I. NEW HAVEN, Cut. LS 0898: an THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE STREET. ip Published monthly. Six dollars per year, in advance. $6.40 to countries in the _ Postal Union ; $6.25 to Canada. Remittances should be made either by, tne Ro _ registered letters, or bank checks (preferably on New York banks), RARE CINNABARS FROM CHINA. We have still left a small lot of these remarkable Cinnabar specimens which were described and illustrated in the November issue of this Journal. Write for prices and illustrated pamphlet. NEW ARRIVALS 3 Euclase, Capo do Lane, Brazil; Terlinguite, Terlingua, Texas; Eglestonite, Montroydite, Terlingua, Texas; Patronite, S. A.; Uraninite, erystal in matrix, Portland, Conn.; Benitoite, San Benito Co., Cal.; Neptunite, Cal.; Crookesite, Hedenbergite, Sweden ; Lievrite, Elba ; Polybasite, Hungary and Durango, Mexico; Josephinite, Oregon; Herderite, Maine; Smithsonite, Kelley, N. M.; Californite, Tulare Co., Cal.; Cobaltite, loose crystals, and in matrix, Cobalt, Ont., and Tunaberg, Sweden; Apatite, Auburn, Maine ; Vivianite, large crystals, Colo.; Vanadinite, Kelley, N. M.; Monazite, Portland, Conn.; Oliv enite, Utah ; Sartorite, Canton Wallis ; Jordanite, Binnenthal : Mohawkite, Algodonite, Domeykite, Michigan ; Crocoite, Siberia and Tas- mania ; Cinnabar, Cal. and Hungary ; Dioptase, Siberia ; Diopside, with Essonite, Ala, Piedmont; Embolite, Australia; Gypsum, twin crystals, Eisleben, Thuringia : Diamond, in matrix, New Vaal River Mine; South Africa ; ‘Brochantite on Chrysocolla, Utah; Pink Beryl, small and large, Mesa Gr and, Cal.; Kunzite, small and large, Pala, Cal.; Sphene, Binnenthal, Titanite, Tilly Foster, N. Y.: Tetrahedrite, Utah and Hungary ; Realgar, Hungary; Opal, Caribou River, Queensland : Octahedrite, var. Wiserine, Binnenthal; Heulandite, Iceland; Paper Calcite, Saxony ; Torbernite, Hng.; Bismuth, native, Cobalt, Ont. and Conn.; Silver, native with Breithauptite and Smaltite, polished, Ont.; Emerald, loose crystals and in matrix, Ural and Bogota; Topaz erystals with rare planes, Ural; Zircon crystals, loose, Ural; Green and Cinnamon Garnets, Minnot, Maine; Vesuvianite, Poland, Maine, Italy and Tyrol; Zeolites, beautiful specimens from Erie Tunnel, Patterson and Great Notch. CUT GEMS. We have left over from our Christmas trade a very fine and varied lot of large and small Cut Gems, which we are offering at unheard of low prices. We name a few below :— Garnets, green and red; Aquamarines; Zircons, all shades: Sapphires, all shades ; Star Sapphires and Star Rubies ; Chrysoberyl, Cats-eye ; Spinels, all shades; Topaz, pink, blue, brownish and golden color; Pink Beryl; Sphene; Tourmaline, all shades; Amethyst, Siberia, royal purple color; Andalusite; Star Quartz; Peridote; Opal matrix, Mexico and Australia ; Precious Opal, Australia, Mexico and Hungary ; Hyacinth ; Turquoise, Mex- ico and Persia: Kunzite; Reconstructed Rubies and Sapphires ; Emeralds ; Opal Carvings, such as pansies, vine leaves with bunches of grapes, and other small Opal novelties; Antique and Modern Cameos ;. Antique, Mosaic and other semi-precious stones. Let us know your wants, and we will send the specimens on approval to you. A. HA. PETEREDS 81—83 Fulton Street, New York City. Ks ree oF a i ee a ee or THE AMERICAN JOURNALOF SCIENCE [FOURTH SERIES.] 0 Art. 1.—Diopside and its Relations to Calecwm and Magne- sium Metasilicates ; by E. T. Attew and W. P. Warrs. With Optical Study; by Freep. Evcenr Wricut and Esper §. Larsen. (With Plate L.) THE pyroxenes were chosen some time since as a good subject for laboratory investigation, both by reason of their geologic importance and because their comparative stability and simplicity of composition seemed to offer relatively little difficulty in their synthesis and study. Diopside is the sim- plest of this group of minerals, but before even this could be studied satisfactorily, a detailed investigation of both calcium and magnesium metasilicates was found necessary; a full account of which has been given elsewhere.* Here it will be sufficient to state that calcium silicate exists in two crystal forms, one of which, the mineral wollastonite (@-form), is stable up to about 1190°, when it reverts to a pseudo-hexagonal form (a-form) which melts at 1512°. The case of magnesium metasil- icate is more complex. There is one form (monoclinic) strongly resembling the pyroxenes, both optically and crystallographic- ally, which is stable up to 1365° (@-form). Here it passes over into an orthorhombic form (a-form) recalling forsterite (Mg,SiO,) in its habit and optical properties. It melts at 1524°. Three other forms exist, viz., the minerals enstatite, kupfterite, and a monoclinic amphibole similar to the latter. _All are monotropic, and change into the 6-form when heated to a sufficiently high temperature. The question of the relation of diopside to its component salts, calcium and magnesium silicate, we undertook to settle by determinations of the melting point and specific volume * Allen, White and Wright, this Journal, xxi, 89, 1906; Allen, Wright and Clement, this Journal, xxii, 385, 1906. Their form, then undiscovered, is described for the first time in these pages. Am. Jour. Sct.—FourtH Series, Vout. X XVII, No. 157.—Janvary, 1909. 1 2 Allen, ete.—Diopside and its Relations curves, relying on very careful microscopic examinations to make sure of the solid phases which separated from the molten solutions. Since we are concerned here with eguilebrium conditions, it will be evident that the monotropic forms of magnesium silicate do not enter into the problem.* In addi- tion to this specific problem, viz., the relations existing between the calcium and magnesium silicates, we planned to study the most important properties of diopside and its transtormations on heating, if any. Many of the methods used im this investigation have been already described in previous papers from this laboratory ;+ others have been devised in the course of the work. Preparation of the Mixtures.—Quartz, magnesia and cal- cium carbonate were mixed in the proper proportions and melted in large covered platinum crucibles. The molten charges were chilled by dipping the crucibles into water, cracked out of the crucibles, crushed fine, and remelted to ensure thorough mixing. All the materials were carefully examined for impurities, and we are able to state with cer- tainty that the products contained no more than 0:1 per cent to 0-2 per cent of foreign matter, except in certain cases where the same preparation was repeatedly melted and crushed, when as much as 0°3 per cent impurity was sometimes found. We had considerable trouble in getting magnesia sufficiently » pure for our purposes. The chief impurity is generally lime, of which all the samples examined by us contained 0°5 per cent or more. At our request, the firm of Baker & Adamson under- took the problem of preparing pure magnesia in quantity, and succeeded in making a “ basic carbonate” in which the mini- mum quantity of lime amounted to about -07 per cent, or 0°15 per cent of the calcined oxide. A sample of magnesium metasilicate prepared from one lot of this carbonate gave by direct test 12 per cent lime. In mixtures very high in mag- nesia a correction was generally made for this impurity, 1. e., the proper deduction was made from the quantity of lime required by the particular mixture in hand. For the sake of control we analyzed two of the preparations and the results are given below. At one time during the investigation, it was suspected that some loss might be caused by the strong blast of the gas fur- nace in which the constituent powders were first melted together in spite of the fact that the crucible was carefully covered. The magnesia being by far the lightest of the constituents *Viktor Péschl incorrectly designates the series ‘‘ enstatite-diopside,” Centr. Min., 1906, p. 572. + This Journal, xix, 125, 1905; xxi, 89, 1905; Tschermak’s Mitth., xxvi, 169, 1907. =o. Oo to Calcium and Magnesiwm Metasilicates. (magnesia, calcium carbonate, quartz), its loss would be dispro- portionate to its weight in the mixture. But the analysis of the 60 per cent MgSiO, mixture, in which the magnesia was slightly high, shows that the suspicion was unfounded. Found @alt fete MoSiOe 205.55 DLT us eee gia 5D Pe = 52°67 BU OB SIO | oot CaO roe Gees 43°52 43°38 Mo Qiu wae ss 2 4°06 4°00 Be OW ete a= ‘11 ee 100-44 100:00 2607 MesiO. i222 DOM oe tes 56°80 56°73 Oh) Caso eee. CaOeie eee 19-12: 19°26 Mig Ome. 152 ess 24°11 24°01 e:O: sete. e222 “183 Eigen 100°16 =100°00 Thermal Study.—The thermal study was carried on, as in other published work from this laboratory, by F rankenheim’s method, melting point curves being used exclusively. Freez- ing- _point curves are unreliable on account of the undercooling, which, even in substances which crystallize as readily as the metasilicates of calcium and magnesium, is often considerable. The mixture under investigation was heated in a platinum crucible, in an electric resistance furnace fed from a stor age battery, ‘the temperatures were read to tenths of a degree by a Le Chatelier thermoelement and a potentiometer, and evalu- ated in terms of a standard saturated cadmium cell. Since the work here described continued over a considerable period of time, the methods used varied somewhat as sncces- sive improvements were introduced. In the earlier portion of it, charges of about 25 grams were used, and the thermoelement was protected by a porcelain tube with a platinum jacket. A control element was also employed to detect any irregularity in the heat supply.* Soon after the work was begun, the practice was also instituted of comparing the thermoelements with standards in order to correct for their deterioration,t due to contamination with iridium from the platinum crucibles and furnace coil. This has now been greatly reduced by using specially pure platinum within the furnace, but occasional com- parisons with standard elements are still necessary.{ Fre- quently the thermoelements were inserted together in the porcelain tube and used to read the same melting point. The * This Journal, xxi, 94, 1906. + The Constancy of Thermoelements, W. P. White, Phys. Zeitschr., viii, 325, 1907. + W. P. White, Phys. Rev., xxv, 336, 1907. 4 Allen, ete—Diopside and its Relations readings when separately corrected then seldom varied 4°, which was about the accuracy with which ‘any two working ele- ments could be compared. The variations in the results, some- times amounting to 2°, even with the-more sharply melting substances (the end members, the eutectics, and diopside), were therefore due to uncertainty in locating the melting point, and not to the temperature measurements. In the latter part of the work, charges of only 24 grams were used, in very small crucibles of pure platinum, in which the naked thermoelements could safely be immersed. Under these conditions and with proper precautions, the variations rarely exceeded $°. The small crucibles could also be more easily moved in the hot furnace, chilled in cold water, etc., and a wider range in the conditions of crystallization obtained. Furthermore, the thermal lag of the dimimutive charges was very small, and complex thermal phenomena could be analyzed or separated with much greater certainty than with larger ecru- cibles. The small crucibles were mainly used in investigating those portions of the field in which the interpretation of the phenomena had proved particularly difficult. They were used, however, in a sufficient number of cases to afford a thorough control of the earlier determinations made with 25 grams, and showed that these were accurate within their own accidental errors. The agreement obtained between observations of the same point in both the earlier and later work is well illustrated in the following table: TABLE 1. Agreement of Observations in Earlier and Later Work. Temperatures in microvolts. About 18 microvolts to 1°. 70% MgsSi0;: 30% CaSiOs. 28% MeSiOs : 72¢7CasiQs. 20 gr. charge. 24 gr. charge. Sunes Ose eee 14,147 Oct: 1907. 2) 2 aaa 130 776 110 TH, 138 Ti, 148... pirat: tay cee Mean 2222) 14,133 13,7 06x Average deviation, 11 my. 2 mv. Extreme s 37 mv. a faa 08g These particular instances were selected for illustration as being, each in its class, the one showing the largest number of strictly comparable observations. Each one is typical, and to Calcium and Magnesium Metasilicates. 5 neither is the best that could be given. Each represents three ~ _ different charges. A word :as to the exact significance of the accuracy here indi- eated may avoid some contusion. In comparative measurements with very small crucibles (2°5 grams) and bare thermoelements, the relative accuracy obtain- able by the same observer with the same apparatus is $° or better ; with the larger crucibles (25 grams) and jacketed ele- ments, differences may reach 3°, This is shown in Table I, page 4. The absolute value of the measurements is not established with this accuracy. Different observers, indeed, working inde- pendently with different apparatus, ought not to differ much in their results through differences in experimental iethods, provided these are not positively faulty ; that is, provided the thermal junction is actually at the temperature of the melting material. This is shown by the agreement of our earlier and later results, obtained with highly differing methods, and also, perhaps more conclusively, by the agreement found between Dr. Day’s special form of element* and the ordinary jacketed element. Differences between independent observers are, how- ever, to be expected in the thermoelement calibration, partic- ularly at the present time, when a long extrapolation is necessary. Practically all temperature measurements above the melting point of copper (1084° C., Reichsanstalt Scale) are now obtained by extrapolating some simple function which has been experimentally established for temperatures below that poit. With the same function and different elements, temperatures usually do not vary more than 2° C. at 1,500°. With different functions, the extrapolated curves may diverge as much as 30° C. at 1,500°. An error of 0°5° in the determi- nation of the copper point itself may cause an error of 4° in the extrapolated curve at 1,500°. All these are differences in the interpretation of the experimental measurements, which will probably continue to cause considerable differences between the results of different observers until the gas ther- mometer scale is extended to that temperature with sufficient accuracy, after which they can be readily recomputed to the established scale. The temperatures here given are com- puted from the Reichsanstalt Scale. In brief then, the accuracy * Carnegie Institution Publication No. 31, p. 25. Our value for magne- sium silicate is 3° higher than that found by Allen, Wright and Clement, but this difference is only a little greater than the accidental variations occurring in the present work. With charges of the same size, errors in the method seem most likely to occur, if at all, as the result of a very uneven temperature distribution in the furnace or of insufficient immersion of the thermoelement in the charge. In a few cases where the platinum jacket dropped down so as to rest against the bottom of the crucible, which was cooled by contact with the pedestal below it, the melting point came about 5° too low. 6 Allen, etc.—Diopside and its Relations of the determinations is shown by comparing the measnre- ments among themselves. Their enterpretatcon in terms of an absolute scale depends upon an agreement among observers, and will vary from time to time whenever more accurate funda- mental observations are available. At the present time the Reichsanstalt Seale is generally accepted. The melting points measured, like those obtained in this lab- oratory with the feldspars, and by workers in high tempera- tures generally, are not entirely sharp, even with substances which theoretically should melt at a strictly constant temper- ature. Indications that melting has already begun invariably appear on the thermal curve 20° or 80° below the melting point proper, and the region of strongest absorption of heat is distri- buted over an interval of from 2° to 8°. The main cause of this phenomenon in the present case probably lies neither in any unusual molecular viscosity attending the change of state* nor in experimental error of the temperature obser- vations. It may be due to the slight impurity (1 to 2 per cent) which chemical analysis shows to be present, even in the most carefully prepared artificial mixtures. Similar curves are obtained with ice to which 2 per cent or 3 per cent of salt has been added, and at an absolute temperature five or six times as high the same effect should be produced by about one-thirtieth as much impurity. + The highest portion, that is, the end, of the melting interval is taken as the melting point, since this is probably the nearest attainable approach to what would be the sharp melting point of the substance unaffected by traces of impurity. The Melting Point Curve from O per cent—46°3 per cent MgSiO,,—The temperature- -time curves were taken on a series of mixtures of the metasilicates 5 per cent to 10 per cent apart except in critical parts of the curve, where shorter intervals were chosen. The temperatures at which the heat absorptions took place are plotted in fig. 1. The results in the case of about one-third of the mixtures were controlled by repeating the observations on several different preparations, and since the thermal phenomena in certain parts of the curve were rather complicated, a considerable number of the observations were many times repeated, making in all nearly four hundred inde- pendent determinations. By reference to the diagram (fig. 1) it will be seen that the addition of magnesium silicate to pure calcium silicate (pseudo- wollastonite) lowers the melting point rapidly, the curve fol- * This, of course, is not true of the feldspars, quartz, etc. +In accordance with the Van’t Hoff-Raoult formula, where A, the depression of the freezing point due to impurity, equals ‘02 T? A to Calcium and Magnesium Metasilicates. 4 lowing a slightly curved line to the eutectic point, 1848°, at about 28 per cent magnesium silicate. The curve then rises much more gradually toa maximum of 1380° at the composition of diopside, CaSiO,.MgSiO,, which. contains 46°3 per cent mag-— nesium silicate. Let us first consider so much of the curve by itself. The solid phases, which separated when the mixtures from 0 per cent—46°3 per cent magnesium silicate were crys- tallized as nearly as possible under equilibrium conditions, were proved by microscopic analysis to be only diopside and pseudo- wollastonite, making of course the proper allowance for a small mutual solubility. The latter amounted, as we shall see, to about 3 per cent diopside in the pseudo-wollastonite, and less than 3 per cent of the latter in diopside. The end members, pseudo-wollastonite and diopside, and also the eutectic mixture, melt at a single temperature, with the reservation just made; that is, as sharply as we have yet ob- served with any silicate. The other mixtures show two phe- nomena: (1) the melting of whatever amount of eutectic is present in the mixture; and (2) as the temperature rises, the gradual solution in the melted eutectic of the excess component (diopside or pseudo-wollastonite, as the case may be), which lasts till the melting point curve ABC isreached. The temperature- time curves clearly show continuous change in character from the end members-to the eutectic composition. Near the end member the predominant phenomenon is the upper point, which resembles the sharp melting of the pure component itself ; the eutectic melting is of course small. It is clearly distinguishable, however, even when the mixture contains less than 1 per cent of eutectic. In mixtures farther from the end members in composition, the absorption of heat immediately above the eutectic melting is perceptible, and the highest point gradually takes on more and more the character of the end of this absorption and less and less that of a separate and independent melting poimt. Although, strictly speaking, this upper melting 1s always a solution, the temperature at which it terminates did not show, under the conditions described, any change with the rate of heating. In order to test this question, the rate was in several cases altered from 1° to 3° per minute, but the result- ing effect on the upper point was less than the accidental errors of the separate determinations. As the eutectic composition is approached and the phenomenon has still more the character of a solution and less that of a melting, the upper point becomes less and less distinct. Determination of the Hutectic Composition.—In the imme- diate neighborhood of the eutectic composition the difficulty of determining the upper point is still more increased by another phenomenon. ‘The rapid temperature rise which immediately Weight ¢ MgSiO; Allen, ete.—Diopside and its Relations Upper Point Temperature - Concentration Curve. Taser II. Eutec- tic Inver- sion Weight % Upper Point EKutec- tic Inver- sion 0 24 26 30 51 1510° 1511 1510 pire 40 1273 eyeie en 47°5 ae ets 80 13742 1380° 1380 1381 1379 1381 1381 1381 1380 1378 1378 1377 1377 1378 1409 1408 1412 1416 1452 1453 1452 138472 1343 --+<-+- =e ee DOMPERATURD, to Caletum and Magnesium Metasilicates. 9 Lice & IaNae Sy | eee aia ae Za 'T > = T Nath 1 20 30 40 60 80 90 100 ie, MgSiOs. CONCENTRATION. Principal Areas of the Diagram. AHB a-CaSiO; + liquid. BIC Diopside + liquid. HIMO a-CaSiO; + diopside. OPQM £-CaSiO; + diopside. KOPL Mix-crystals diopside in 8-CaSiOs. CTUSR Mix-crystals of MgSiO; in diopside. CDT Mix-crystals of varying composition + liquid. DEV a-MgSiO; + liquid. TUXV a-MgSiO; + diopside mix-crystals. UXYS $-MgSiO, + diopside mix-crystals. SOD IH OU C9 00 4 TEMPERATURE. 10 Allen, ete.—Diopside and its Relations follows the principal melting now extends beyond the upper point and completely overwhélms it. The difhculty of deter- mining a small residual melting is in striking contrast to the ease with which a slight absorption of heat can be detected below the principal melting.* Owing to this masking of the upper point, a direct determination of the eutectic composition is impossible by the ordinary method; that is, we cannot dis- tinguish within several per cent the mixture which melts leay- Fie. 2. yy 2 eel | ae SS eV Nise Ses Pie ee eee ripe el es alas Eg 3 apa ee Bane eI Bicol MONS ees 7) ¢ MER Swim NeSeees Pal eee et i NEE al oa eels ede 0 See BENS Salalah geal clita Ee ee Ne ees es aed rl il | U e ee eee ENG Ral boats Temperature-time curves of mixtures in the vicinity of the eutectic com- position (pseudo-wollastonite-diopside). I. 24% MgSiOs. II. 26% MgSiOs. III. 28¢ MgSiO;. IV. 32% MgSiOs. V. 36% MgSiOs. . 1330° ing no excess component, since a number of mixtures appear to do so. This is well shown by the temperature-time curves in fig. 2, which were made with especial care with reference to this very point. The upper melting can hardly be distin- guished in the 24 per cent mixture, though this contains over 8 per cent of the component in excess. (The point is in fact so faint that we could hardly distinguish it from the minute irregularities in the temperature curve of the furnace were it not for the fact that it lies on the curve ABO, fig. 1, which is well defined in other mixtures farther removed from the eutectic.) For locating the eutectic two methods still remain. * It was undoubtedly the difficulty of detecting the upper points in this region and the failure to appreciate how easily such an experimental diffi- culty might arise which led R. Freis (Neues Jahrb. Min., Beil. Bd. xxii, 76, 1907) to describe a similar series of melting points as forming a curve with the two inclined portions separated. by a horizontal branch of considerable extent. to Calcium and Magnesium Metasilicates. 11 The first is to extrapolate downward the liquidus curves AB and BC in fig. 1, and take the mean of the points where they intersect the eutectic ine HI. The accuracy of this extrapo- lation is limited by the uncertainty of the liquidus curve for some distance on each side of the eutectic composition. We found with these particular silicates that the results agreed to ear aaee FEMS ae gee HHA a ete — (ol) o> (Yo) oO Neg IS TEMPERATURES. HSC seen mae are HS cee see eee ae ae we TE Hs ag eh ee eZ Riven ntvihd LE ae coer REV dREP SRR REE eles DR eae MA Ee | Time : 4 minute. Location of the eutectic composition. Curves I-I and II-II, 28 per cent and 30 per cent MgSiO; just above the eutectic point. Curves I’-I’ and II’-II’ the same at higher temperature. 5 per cent with a probable error of not over 2 per cent in the eutectic composition. A more accurate determination seemed for some time to in- volve considerable difficulty, but a satisfactory solution of the 12 Allen, etc.—Diopside and tts Relations problem was finally obtained in the following way: Two small crucibles containing charges slightly different in composition were put together in the furnace and br ought to such a temper- ature that the main eutectic melting was completed but the excess component, if any, still left undissolved. Then by sud- denly increasing the furnace current and making alternate temperature readings of the two crucibles at intervals of 15 seconds, the relative heat absorptions in the region immediately above the eutectic melting point could be determined, and thus in a very few trials of different mixtures the eutectic composi- tion could be located. The results of such a determination are shown in curves I-I and II-II, fig. 3. The temperature in II rises more slowly than in if because of an absorption of heat due to the melting of the excess component. The curves were continued to a higher temperature to make sure that this difference was really due to this cause and not to the relative position of the two crucibles in the furnace or to some other accidental cireumstance. ‘The curves I’ and II’ are now paral- lel, confirming the conclusion that their previous divergence was due to a melting in II which is now over. It will be seen from this result that the 28 per cent mixture lies nearer the eutectic than the 30 per cent. A similar comparison of the 28 with the 26 per cent also showed that the eutectic lies nearer the former. These experiments are sufficient to locate the point well within 1 per cent at the 28 per cent mixture. The previous work had indicated that the 28 per cent was probably the eutectic composition. Calculated in terms of diopside, the eutectic mixture would contain in round num- bers 60 per cent diopside: 40 per cent pseudo-wollastonite. Diopside.— As previously stated, the melting-point of diop- side is a maximum on the melting point curve, which fact, taken in connection with the microscopic homogeneity at this composition and the occurrence of a eutectic point on either side of it, proves that it is a compound in stable equilibrium with its own liquid. Abundant confirmation of this conelu- sion is found in the form of the specific-volume curve, p. 27, as well as in the close agreement of the composition of natural diopside with the rational formula CaSiO,.MgSiO,. As an example, we give an analysis of an exceptionally pure specimen from a metamorphosed lhmestone which occurs in Ham Island, Alaska. The composition of the anhydrous substance is also given for the sake of fairer comparison. This is justifiable, for the water is not chemically combined, a conclusion thor- — oughly established by the fact that the substance remains homogeneous as the water escapes. to Calcium and Magnesium Metasilicates. 13 Diopside from Cal. to the Cal. for Ham Island, anhydrous CaSiO; Alaska condition MgSi0; SiO) eo) ut She ee 54°65 55°46 53°63 Ps Cy eee eee 13 13 eee. SaQue sce eC Ape NS OA 25°64 25°82 IO ek erg 18°78 19°06 18°55 NIE CGS Loe er cs eae 03 ete EO ar eee es 33097 ‘O07 sew le Oger oes ed Nice 2). ES aes Ba 100°38 100°39 100-00 When diopside is prepared by melting together lime, mag- nesia and silica in the proper proportions, it crystallizes readily, but not so rapidly as its constituents calcium and magnesium silicates, forming a dense white homogeneous mass with con- spicuous cleavage. The optical constants, a full account of which is given in the second part of this paper, leave no room for doubt of the identity of the substance. Measurable crystals was prepared by crystallizing this prod- uct from molten calcium chloride—Le Chartier’s method.* This may be very conveniently done in platinum as described in a previous paper on magnesium silicate.+ It is not possible, however, to perform the operation in hydrochloric acid gas, as was there done, for the diopside is then decomposed into eal- cium chloride, tridymite and magnesium pyroxene. The last two products were identified optically without ditticulty. The ealcium chloride should first be melted in the sealed crucible, traversed by a stream of dry hydrochloric acid gas. Then after the crucible has been cooled and the hydrochloric acid replaced by dry air, the crucible is unsealed and the silicate quickly introduced. In this operation some moisture doubt- less gets in. Before heating again, dry indifferent gas is introduced. The crucible is heated for a number of days, the entering and exit tubes being guarded by driers. When the operation is completed, the excess of calcium chloride is removed by water. The product is usually in the form of transparent crystals of rhombic habit which sometimes attain to dimensions of several millimeters. The planes are often slightly coated with a thin film of what is probably calcium hydroxide, which doubtless comes from the decomposition of calcium chloride by the water vapor which could not be entirely excluded. It gives a strong alkaline reaction and may be readily removed with a little dilute HCl. Analysis shows that no lime is dissolved by the crystals, though they are not quite tree from chlorine. * Comptes Rendus, Ixvii, 43, 1868. + This Journal, xxii, 389, 1906. 14 Allen, ete.—Diopside and its Relations Cal. for CaSiOs, Found MgSiO; sid, Fay ee Sees ss 55°59 55°62 EES ON ie ge aR RSD gE AGT 3} ORS orc Ss MgO Wy ween otseigie in Mee ORL may tcc Span Hehe G) Sra PEO Petes ae 18 e ER lia Bite ee ANCES Monty 8 ie OE: trace ee, 100°11 100:00 Several products made in this way were united and tested in a mixture of methylene iodide and benzene to see if all was of uniform specific gravity. A small fraction, containing some of the larger crystals, floated, while the rest sank. These er ys- tals seemed to differ from the rest only in porosity. The remainder were then divided into two fractions of only slightly different density and the specific gravity of each was deter- mined by the pycnometer. Sp. gr. at 25° ah HO at 25° 2. Heavier “ ms 3°275 3. Natural diopside from Ham Island, Alaska, cs 3°268 An idea of the expansion of the diopside in the process of melting may be obtained by comparing this constant with the specific gravity of the glass of the same composition : Glass at 30° HO at 25° The description and angular measurements of these erystals are to be found in Part II of this paper. Melting Point Curve from 46°3—100 per cent MgSi0,.— Referring again to fig. 1, it is seen that beyond 46°3 per cent MoSi0,, the addition of it lowers the melting point gradually but very slightly, until about 68 per cent has been reached. Near this point there is an abrupt rise, the curve finally terminating at 1524°, the melting point of magnesium silicate. On the first branch of the curve (46°3-68 per cent) mix crystals of magnesium silicate in diopside sepa- rate. This conclusion was tentatively reached in the prelimin- ary thermal work when it was found that the addition of a large percentage of magnesium silicate lowered the melting point of diopside very little, while the mixtures contimued to show but one absorption of heat. The thermal evidence was subsequently confirmed by the specific volume curve, and by a very elaborate microscopic study. 1. Lighter fraction = Boal): to Calcium and Magnesium Metasilicates. 15 Solid solution determined by microscopic homogeneity ex- tends as far as 66°5 per cent MgSiO,: 33°5 per cent CaSi0,. The solid phases separating on the branch of the curve DE were found to be the mix-erystal just mentioned, and a-MgSi0O, in all cases. All the mixtures from about 68-95 per cent MgSiO, showed an absorption of heat at 1375°. This is evidently a eutectic line and there is no doubt that we have There a case of Roozeboom’s mix-crystal Type V,* where each of two mix-crystals /owers the melting point of the other to a eutectic. Points on this line to the left of the eutectic point could not be located since the liquidus curve lies only 2° to 3° higher up. The eutectic composition is about 68 per cent MeSiO,: 32 per cent CaSiO, and consists therefore of about es = 95°5 per cent of the diopside mix-crystal and about 4°5 per cent of free a-MgSiO, (in which about 2 per cent CaSiO, or 3°7 per cent of diopside is dissolved ). Inversion of MgSiO,.— About 1365° pure magnesium silicate undergoes a reversible change into an orthorhombic form. The heat of transformation is small, and apparently the change does not all happen at once, but extends over quite an inter- val of temperature. This is the only satisfactory way of accounting for the fact that while a small absorption of heat is observed in most of the mixtures of magnesium silicate from 70 per cent on, in the pure substance and in the mixtures near 100 per cent MgSiO, it was entirely overlooked. The exist- — ence of a form stable above 1365° was proved by erystallizing a melt near the melting point, and then suddenly chilling the crystals in water. Thus the form was instantly brought into a temperature region where viscosity was great enough to prevent an inversion. The inversion temperature was deter- mined approximately as follows: One tenth of a gram of the substance was placed in a small platinum tray shaped from a piece of platinum foil. This was suspended by a fine plati- num wire inside the furnace. After the material was melted and crystallized near the melting point, the temperature was lowered to a given temperature and held there about a half hour. The furnace in which the heating was done was designed for calorimetric purposes, and had a removable bottom which was swung aside at the proper moment, when the suspension wire was instantly melted by an electric current, allowing the charge to drop into a basin of water. The results were as follows: * Zeitschr. f. Phys.-Chem., xxx; 403. 16 Allen, etc.-—Diopside and its Relations 1 Chilled from an initial temperature of 1346°; all orthorhom- bic crystals (a-form). -2 Chilled from an initial temperature of 1337°; all the crystals were orthorhombie. 3 Chilled from an initial temperature of 1324°; all monoclinic crystals (8—form). 4 Chilled again from 1324° with the same result. After the existence of the a-form had been established, the inversion point was repeatedly sought for by the Frankenheim method and a very small minimum between 1405° and 1435° was found in many cases but by no means in all, and the point was so small that one might well have hesitated to interpret it as an inversion, had other evidence been lacking. Taken in connection with the sharp heat change which occurs in the mixtures (see below) at about 1365°, it appears that the inver- sion point is overstepped about.40° in both directions, which is in perfect accord with the sluggish behavior of solid silicates. The inversion point in pure magnesium silicate is represented in the diagram (fig. 1) as falling somewhat as it dissolves eal- cium silicate, because this is the relation which commonly holds, but it is manifestly impossible to settle the question at present. a-Magnesium Silicate.—This form, which has already been described, crystallizes in the orthorhombic system in equant crystals on short doubly terminated prisms which resemble forsterite in habit, mdex of refraction and _ birefringence. Its specific gravity, judging from its index of refraction, varies little from that of 8-magnesium silicate (3°192). It was found, by applying the floating method to a single small erystal, to be about 3°16. Fortunately, in several instances a few well- formed, separately developed crystals were found on the sur- face of charges of magnesium silicate which had been melted and crystallized in the furnace, though usually all was com- pletely inverted into the magnesium pyroxene. The measure- ments of these crystals which are recorded in Part II of this paper prove conclusively that this isa form entirely distinct from forsterite or enstatite. Inversion in the Mixtures.—The inversion line is traced in all the mixtures from 68 per cent to 98 per cent magnesium silicate and varies little from 1365.° Some typical curves. showing both the inversion and eutectic points are plotted in figs. 4 and 5, eurves II, V, VI, VII, and VIII. The signifi- cant feature of these curves is the gradual diminution of the heat absorption at the latter (eutectic) temperature and the gradual increase of that at the former (inversion), as we pass toward 100 per cent magnesium silicate. Thus in the 70 per - cent mixture the eutectic melting is large, while in the 95 per to Caletum and Magnesium Metasilicates. 17 Fie. 4. eee eee EE A Mee iss lee ral | Tele tI CEE CEC __ SJE ASa See e Zee ase eee . JeRS ESE eeeaseenee El al _~ JUS RUE ERR RERR ee Se! ia | Ee saan SERA) pee see ert ey EEE SR GR ey see ney conn ee nee SUSIE EE Bild H+ Temperature-time curves showing thermal Selstae of. mixtures rich in MgSiOs. Curve I-I, 60 ¢ MgSiOs. II-II, 70 4 MgSiOs. Fig. dS PLCC - {TSE RSaRRRREE S/S0c0ee eee EEEECCCCCECC CE __ CUS RRB RES See ae ane ee ee ee ee V7 eee ea Ae Ss SRReSEeSes a ae PCE ere SERERY CEO ZGEORRES Ae ae | OGRE aes Zeek ee SE HA a eer eee ee a eer _-. 625 0SSeasee aes sade e eee eee Temperature-time curves showing thermal behavior of mixture rich in MgSiOs. Curve IIT. 65 @ MgSiOs. coy ers Se a MgSiO. ery stallized below 1300° by heating the glass. rs V. 73% : not far below 1365". se WA 80 % “e “é ‘é Vil. 90 & ce ce ce ce a4 ce “ec VII. 95 4 “e ce “ce ce ‘cc a4 Am. Jour. Sct.—FourtH Serres, Vou. X XVII, No. 157.—Janvuary, 1909. 2 13909 | 1380° 18 Allen, ete.—Diopside and its Relations cent it is minute and in the 98 per cent can be no longer detected ; while the inversion, small in the 70 per cent mixture, is much greater in the 90 per cent and 95 per cent mixtures. The 98 per cent mixture, where solid solution of calcium sili- cate begins, shows the inversion plainly but not so markedly as the 95 per cent mixture. It evidently partakes of the char- acter of the pure silicate, which is more resistant to rapid change. Dissolved calcium silicate therefore facelitates the inversion of magnesium silicate, while, as we shall presently see (page 20), dissolved magnesium silicate hinders the inver- sion of calcium silicate. It is not strange that the properties of a substance should be modified by solid solution, though it is evident that the direction of such a change cannot yet be pre- dicted, but why an excess of foreign solid should affect the inversion point of a substance is not clear. The influence of solid diopside in concentrating or sharpening the inversion of magnesium silicate, however, seems to be established. Curves I and III show the behavior of materials which con- tain no free magnesium silicate and therefore show no inversion. Curve [IV shows what happens when mixtures are chilled to glass and then heated. Crystallization then leads to enstatzte, which evolves heat slowly over a long range of temperature. Since this evolution covers the region above 1300°, the small absorption at 1365° is effectually hidden, where, as explained, the inversion seems to be lengthened out. Solid Solutions.—The system CaSiO,-MgSi0, contains six different series of solid solutions, in only two of which is there more than a few per cent of the smaller constituent. The limit of solubility was determined by the thermoelement, by the microscope or by both when possible. So far as thermal tests are concerned, the results refer of course to the presence or absence of a eutectic melting, 1. e., the solubility at the eutectic temperature is approximately determined. The microscope, on the other hand, makes its determinations at ordinary temperatures, where presumably the solubility is generally greater. In almost all cases the solu- bility as determined by the microscope is a little higher, but how far this is a real difference and how far it is due to a differ- ence in the delicacy of the methods, it is unsafe to say on account of the uncertainty in establishing equilibrium in these solid silicate solutions; in other words, it is impossible to say whether a given solution is saturated or not. In the diagram, fig. 1, we have drawn the lines straight with a single exception, where we have more evidence that solubility increases with falling temperature. 1. Diopside in a-MgSiO,. On account of the difficulties involved, this series was not investigated. to Calcium and Magnesium Metasilicates. 19 2. Diopside in B-MgSiO,. The microscope detected inho- mogeneity in the 3 per cent CaSiO, mixture, but none in the 2 per cent. No eutectic was observed in the latter. We may therefore put the solubility as 2 per cent CaSiO,, or 3°7 per cent diopside. 3. MgSiO, in diopside. The microscope places the limit of solubility at about 66°5 per cent MgSiO, : 33°5 per cent CaSi0,, 1. e., the quantity of diopside in the saturated mix-crystal would be 33°5/53°7 = 63°4 per cent. In other words, diopside is capable of dissolving 37°6/62°4 = more than 60 per cent of its own weight of magnesium silicate. This remarkable series of mix-crystals strongly resembles diopside. The optical work described in detail in Part Ii shows that the extinction angle and the optic axial angle both fall about $° for each additional per cent of magnesium silicate. The specific volume curve (fig. 9) shows that the solution is attended by expansion. 4. Calcium silicate in diopside. The microscope detected inhomogeneity at 44°5 per cent MgSiO, while the thermoelement detected a plain eutectic in the 45 per cent MgSiO,. The limit of solubility is doubtless small, certainly less than 100— 45/46°3 = 3 per cent CaSiO,,. 5. Diopside in a-CaSiO, (pseudo-wollastonite). Mixtures containing as much as 8 per cent MgSiO, plainly showed inhomogeneity when examined by the microscope. The inhomogeneity took the form of irregular bands, irregularly distributed, which showed a distinctly lower birefringence than the rest. The 2 per cent MgSiO, solution showed traces of the above structure and gave a plain eutectic when examined thermally. The 1 per cent solution is microscopically homo- geneous and gives no more than a suspicion of aeutectic. The error will be shght if we put the limit of solubility at about 1-2 per cent MgSiO,, or in round numbers, 3-4 per cent of diopside. 6. Diopside in 8-CaSiO, (wollastonite). In this case a thermal test is obviously useless. The microscopic analysis showed that solution ceased at about 17 per cent diopside (8 per cent MgSiO,). Crystallization took place at about 1058°. The crystals of diopside and wollastonite are both monoclinic and the latter resembles diopside more closely than pseudo-wollas-' tonite, so that it is not surprising that wollastonite should dis- solve diopside in large quantity. These solutions showed a very interesting behavior when they were heated. To understand this clearly, it should be remembered that the eutectic between pseudo-wollastonite and diopside melts at about 1348°, while wollastonite has an inver- sion point at about 1190°. Upon heating crystals of wollaston- 20 Allen, etc.—Diopside and its Relations ite carrving 1 per cent MgSiO, (2:1 per cent diopside) for one hour at 1221°, no change was apparent. Heated again for two hours at 1245°, the inversion was slight. The inversion point of wollastonite appears, therefore, to be raised 40°—50° by the solution of only 2 per cent diopside. (See p: 187} Since time is an important factor in sluggish changes, a direct comparison was made between pure wollastonite and two mix-crystal preparations of this series by heating all three in the same furnace for the same length of time, viz. 1 "homme The temperature ranged from 1257° to 1263°, i. &,. about 65° above the inversion point of wollastonite. The wollastonite was completely inverted, the 2-1 per cent solution slightly inverted, while in the 4°3 per cent solution (2 per cent MeSi0,) it was doubtful if any change at all had taken place. The two solid solutions were now returned to the furnace and held an hour longer between 1273° and 1300°,.about a hundred degrees above the inversion point of pure calcium silicate. The weaker solution was now found to be much changed, the stronger one less so. The 8 per cent solution of MgSiO,, containing 17°3 per cent diopside, was heated for an hour at 1278° to 1280°, 90° above the inversion point of calcium silicate. A car eful microscopic examination of the crystals then showed a con- siderable change in their appearance; a new product had sepa- ~ rated but it did not show the ohamanien istics of pseudo-wollas- tonite. Such optical properties as could be measured in fine- grained material (index of refraction, birefringence) agreed with diopside. This indicates that the solubility of diopside in wollastonite is greater at lower temperatures where the crystallization occurred, or perhaps that the solid solutions, being formed by rapid erystallization, were supersaturated. In either case the excess separates when the solution is heated to - higher temperature. Heated an hour longer at a temperature of 1298°—1308°, more diopside separated, but the signs of inversion were still doubtful. Again, the crystals were returned to the furnace and the heating continued another hour at 1327°-1348". This time inversion was evident. These experiments show either a marked rise in the inversion temperature of wollas- tonite or else a great increase in molecular sluggishness caused ‘by the dissolved diopside. A brief discussion will make it clear under what conditions an inversion point may be raised and thus help to decide whether we have a real rise in the inversion temperature or not. By a thermodynamic method Beckman* has shown that the freezing or inversion point of a substance is changed by * Ostwald’s Lehrbuch der Chemie, vol. 2, pt. 2, pp. 38, 68. to Calcium and Magnesium Metasilicates. ZE Taste IIL. Inversion Temperature of Wollastonite-Diopside Mix- Crystals. (Inversion point of wollastonite, 1190°.) of Composition of Peeeer) Results. Exper. ‘Heating eh 1 1% MgSiOs; (2°1% diopside) Eber: 1221° No change. 2 1% MgSiO; (2°1% diopside) 2 hr. 1245° Inversion slight. Continuation of Exper. 1 0% MgSiO; Completely inverted. 3 1% MgSiO; (2°1% diopside) hr. 1257--1268° Slightly “ 2% MgsiOs; (4°5¢ diopside) Doubtful (1¢ MgSiO; (Continuation : oy > § Largely inverted és 1 24 MgSiOs of Exper. 3) foe; Les Muchless ‘‘ > 84 MgSiO; (17°3¢ diopside) hr. 1278-1280° Separation of diopside. No inversion. 6 8% MgSiO; (17°3% diopside) (Continuation of Exper.5) lhr. 1298-1303° Inversion doubtful. 7 Continuation of Exper. 6 lhr. 1827-1848° ‘¢ evident. re: 76: To Hs Fic. 6 shows under what conditions an inversion point remains unaltered after the formation of a solid solution. the solution of another substance according to the equation O25 1? mgt iT —(C,—C,) where A = the depression in the tem- perature, T = the absolute temperature of the inversion point in the pure substance, / = its latent heat of fusion, C, = the con- centration of the solution above the inversion point and C, = the concentration of the solution below the point. 22 Allen, etc.—Diopside and its Relations This formula holds approximately for concentrated solutions. When C, = C,, i. e., when the concentration of the solid solu- tion is not changed by the process of inversion, there will » evidently be no change in the inversion point; when C,>C,, the temperature will fall, but if C,, the concentration below the freezing point, is greater, then A will have the opposite sign, and the freezing point will be higher than that of the pure substance. The same conclusion is reached by a graphic method.* In | fig. 6 let AB represent the vapor pressure curve of the pure solid below the inversion point, BC the vapor pressure above it, and T, the inversion temperature. Now if this solid forms a solid solution, the vapor pressure of the former will be lowered according to the concentration of the solution. Sup- pose that this is the same above and below the inversion point, and that the vapor pressures are lowered to the same degree in both. It is evident that the new curves DE and EF will inter- sect at the same temperature and the inversion temperature is therefore unchanged. i In fig. 7 let us suppose that the concentrations of the two solid solutions are unequal, the one below the inversion point being the more dilute. The curve AB will be lowered to DE and BC will fall to EF by reason of the greater concentration of the second solution. DE and EF now intersect at E, at a temperature lower than T,. By similar reasoning we conclude that when the solid solution below the inversion point is the more concentrated the inversion point will be raised. (See fig 8.) Apparently the lower concentrations of diopside in wollastonite remain the same when the mix-crystals invert, for about 1-2 per cent MgSiO, is dissolved by the pseudo- wollastonite. In these cases,\therefore, the inversion point theoretically should not change. ‘These solutions, however, are unquestionably less changed at the same temperature than wollastonite is. We therefore conclude that the solution of diopside has increased the intermolecular friction of the crys- tals. It is also possible that these solutions of wollastonite- diopside which are more concentrated than 1-2 per cent MgSiO, really have a higher inversion point than 1190°. If the crystals saturated at this temperature remain more con- centrated in diopside than the pseudo-wollastonite is, this must. be true. A decision cannot be reached until we have some sure metiod of establishing equilibrium. Day and Shepherd found that solid solutions of lime or silica in calcium metasili- cate inverted to wollastonite on cooling. Since the pure meta- silicate does not behave so, we naturally conclude that the internal friction was lessened by the lime or silica. Magnesium * Bodlander, Neues Jahrb. Min., Beilage Bd. xii, p. 52. to Calcium and Magnesium Metasilicates. 23 metasilicate has no such influence. The 4:3 per cent of diop- side in pseudo-wollastonite was cooled from 1209° to 1050° during a period of 1% hours without producing any change in the crystal form. In the diagram, fig. 1, we have drawn a ieee el a Fie. 7 shows under what conditions the inversion point of a solid is depressed after the formation of a solid solution. dotted line through the points where this series of solutions was actually observed to invert, but it must not be accepted as a true inversion line. The inertia of these mix-crystals of wol- lastonite causes them to exhibit a curious and variable behavior GaSe ie A D 0 Ty T P| SES ea en SSNS Fie. 8 shows under what conditions the inversion point is raised after the formation of a solid solution. 24 Allen, etc.—Diopside and rts Relations when heated, which in the beginning of the work was quite confusing. The normal behavior of a solution of wollaston- ite containing more than 2-4 per cent of diopside, (the limit of solubility of the latter in pseudo-wollastonite) would be as follows: First, an inversion should occur somewhat above 1190°, giving crystals of pseudo-wollastonite saturated with diopside, and an excess of free diopside. At 1348° some eutectic melting would be noted, and finally, when the melting point curve is reached, another thermal point would be found. Under ordinary experimental conditions, however, where the rate of heating is about 3° per minute, solutions containing 5 per cent MgSi0, (10°8 per cent diopside} showed no melting at the eutectic temperature. Evidently no mversion had taken place. When the rate of heating was considerably slower a slight eutectic melting was noted, while if the crystals were previously held for some time at 1360°, there was a strong absorption of heat at the eutectic temperature. In the 8 per cent MgSiO, solution (17°3 per cent diopside) the eutectic failed in one instance, 1. e., there was no melting at the eutectic temperature. Mixtures of saturated mix-crystals of wollaston- ite-diopside give, when the heating is not too slow, three points, the eutectic at about 1348°, a further melting accompanying the inversion at a higher temperature,* and finally, the point on the melting point curve where all becomes liquid. ‘Thus the 10 per cent mixture (containing about 4 per cent of free diopside) showed heat absorptions at 1340°, 1877° and 1451°. The 8 per cent solution showed a similar behavior, indicating that some inversion may have occurred below the eutectic points. Another explanation is perhaps more probable, viz.: that the lowest point may be due to an unstable eutectic between wollas- tonite and diopside, since the latter was found to separate from the more concentrated solutions at the higher temperatures. If so the point hes very near the pseudo-wollastonite diopside eutectic. A fact that seems to favor the explanation is that the 10 per cent solution always gives this lowest point although it has been proved that the more concentrated solutions invert with greater difficulty. Moreover, when the 28 per cent solu- tion was crystallized below 1190° and therefore contained no pseudo-wollastonite (a conclusion also verified by the micro- scope), all melted at 1358° as usual. Specific-volume curve.—In 1890 Retgerst stated clearly two arguments to prove that diopside was a chemical compound in distinction from a mix-erystal. The first was that the minerals in nature which contain the metasilicates of calcium and * Since the solution of the diopside in the wollastonite crystals prevents partly or wholly the eutectic melting at the proper temperature, this melting will at once occur when the crystals are inverted. + Ann. Ecole Polytech. de Delft, iv, p. 186, 1890. to Calcium and Magnesium Metasilicates. 25 magnesium vary comparatively little from the compositions CaSiO,, MeSiO, and CaMgSi,O,; and the second, that the specific volume of diopside could not be calculated additively from the volumes of the constituents. Retgers’s method of solving the question of isomorphism or isodimorphism between two substances is well known.’ It consists in the preparation of a suitable series of mix-crystals of the two substances and a study of the relation which their specitic volumes bear to one another. He proved by many examples that the specific vol- umes of isomorphous mixtures (as he defined them), when plotted as a function of the composition, form a straight line. In the paper quoted above, Retgers said that this would be the best way to prove whether calcium and magnesium sili- cates form a double salt or are isodimorphous, if their mixtures could only be crystallized in sufficiently large individuals for specitic gravity determinations. He used the floating method, which is not adapted for very small particles, and he empha- sized the importance of making sure that the material is both physically and chemically homogeneous. He therefore used only transparent individuals for fear that aggregates might contain some foreign material which would escape optical detection. It has been shown in this laboratory that the spe- cific gravities of mineral powders, if not évo fine (100-120 mesh), can be determined with a degree of accuracy (+001 for substances of the gravity of 3) very nearly as great as those obtained by Retgers’s method. Of course, the particles should be free from air bubbles or vacua, and it must be admitted that powders require a very car eful microscopic investigation to decide this point. Mixtures of calcium and magnesium silicate generally show a certain amount of “dustiness” due to very minute inclusions, or more probably to vacua. These are more numerous in the mixtures which are rich in mag- nesia (70-97 per cent). but not in the pure magnesium silicate itself. When large masses of material (100 grams) are crystallized slowly, the density is greater and the microscope shows that. the vacua are fewer and smaller. Although the specific gravities of the mixtures crystallized in this way are still too low, we judged that they would probably be approx- imately comparable among themselves, and this conviction ‘ has been justitied by experiment. The specitic-volume curve (fig. 9) plainly consists of three branches. AB is the locus of the volumes of mechanical mix- tures of the pseudo-wollastonite and diopside (leaving out of the question the small mutual solubility). Independently of microscopic or thermal evidence, it would, of course, be impossible to say whether this line indicated a series of mechanical mixtures or a series of mix-crystals between two 26 Allen, ete.—Diopside and its Relations isomorphous substances. In either case the volumes would form a straight line between the two constituents. DO is made up of diopside mix-crystals with magnesium silicate. The limit of the solubility of the latter in diopside is at about 70 to 72 per cent MgSiO, as determined by the specific volume Tasue LV. Specific Gravities and Specific Volumes of Mixtures of CasiO, and MgsiO.,. Sp. ar: Sp. v. 0% Mesi0, oe WAY ee So REN a 2°912 °3434 8 of Seg em ee Mie Th 2°965 3373 10 rR Riel te Neonat ante eT Sn 2°947 3362 20 ae Winn soe ama Mire ARNE rat acne 3°046 3283 30 SMe ake eae Lenn yt MMR Read 2 3°11 3215 40 Goh) gp ae Moho Megs aul nn a 204 °3125 Ah pie ee irre | OER ak ae 2 eM es ea cena 3°229 °3096 32237 °3089 46°3 Eee sie a PR Os Ge As Ep AONE) °3090 3°24] °3086 ALI) BEG Ohya taal Clie eRe ae ts 3°246 3081 50 PATTEM SE de Rs Rete Ne ao 3°245 3089 3°255 °3072 55 CERI Ay ge our nae 3°24) °3086 3°24 1 60 ee BA Ata ci me eed Pat 0 3229 "3096 65 Beas Pe Conga for AN Tae ne, tae Bey 3115 3°212 70 SO ta churtes Lh Ba MRE IE a 3°205 °3120 3°198 nie 2 af ip ten ay hes alee! 3°196 °3129 3°196 [oO om 5 i eres SAIS MEIER | SUF th Cots 3°194 °3130 80 Fee a ed gy i ate 3°198 sol 2g 3°192 3132 85 Bei Boece 98 Sie ae ee a a ae 90 Se tpi Ney Ln in 7 RR tame 3°188 “ola k 95 re RRL Aaa es ORE a 8t "3140 100 FEN ete AC Lee So pee a 3°193 "3132 Where two different numbers are given, they belong to different prepara- tions. eurve. The microscope sets the limit at about 66:5 per cent. The discrepancy is probably due to experimental error in the specific gravity determinations caused by the presence of bub- bles in the grains. An inspection of the curve shows that the volumes of these solid solutions all lie above a line joining b and D. They are, therefore, greater than the volumes calcu- to Calcium and Magnesium Metasilicates. 27 lated on the assumption of a purely additive relation. A sim- ilar expansion is known in other cases.* CD contains the volumes of mixtures of magnesium silicate and the diopside mix-crystals. The minimum B, indicating a compound, falls at about 49 per cent MgSiO, instead of 46°3 per cent, which is demanded by the formula CaSiO,.MgSiO,. This is because a Fie. 9. ele a ee eee ee ee yee eel drei 4 wie eee pe emer ee ho feces bodende i ¢ SPECIFIC VOLUME, LOT cone a) 2.40.62 50" 6017082 80) 90) 110 CaSiO3 MgsiO, Weight per cent. melt of the latter composition forms a crystalline mass which always appears to contain more bubbles than the other compo- sitions In its immediate neighborhood, so that the density of the crystals is not only absolutely but also relatively too. low. It will be remembered in this connection that the diopside which was crystallized from calcium chloride had a specific gravity of 3°275, while that which was crystallized trom a melt of the composition CaMgSi,O, had a density of only 3°24. * EK. S. Shepherd, Journ. Phys. Chem., viii, 245, 1904. 28 Allen, etc.—Dviopside and its Relations - We made a number of experiments with the intention of finding whether the mix-crystals of diopside and magnesium silicate could be erystallized again from calcium chloride, or if not, what change in composition they would show with varying quantities of the chloride, but the products obtained were not only not homogeneous, but the crystals were too small to sepa- rate from one another and the microscope was unable to identify them. One difficulty in these experiments was the impossibility of entirely excluding water from the apparatus. Its reaction with the calcium chloride, of course, formed some free lime, which was dissolved by the silicate. Pure diopside, as we have seen, does not dissolve lime, but magnesium silicate does. Three grams of the latter, containing only 0°12 per cent of lime, was crystallized* from calcium chloride and analyzed after the excess of the reagent was removed. It now contained 3°04 per cent of lime, an increase of 2°92 per cent. | Part Il. Optical Study, by Frup. Euemne Wriagut and - Esper 8. Larsen. In the foregoing pages the theoretical aspects of the Ca-Mg- metasilicate problem have been treated at length, evidence from all sources, chemical, physical, optical and_ erystallo- graphic, having been brought to bear on its solution. In this general presentation of the problem, however, only the more important and decisive optical and crystallographic data have been made use of, their detailed tabulation having been reserved for a separate section. In the following paragraphs those details which are still lacking are listed, and in order to avoid repetition, general theoretical considerations have been avoided so far as possible. In the attack on the present prob- lem the effort has been made from the very first to combine the evidence from all viewpoints and to test each conelusion by such evidence. It has been found that by this method the constant interchange of ideas and the discussion of the details of the problem have tended greatly to improve and to strengthen the final result. For the sake of convenience the optical and crystallographic features of the three compounds of this series will be considered first, after which will follow the particular features of the intermediate preparations. Calcium Metasilicate—The two enantiotropic forms of this compound, wollastonite and pseudo-wollastonite, have already been described in detail in this Journalt+ and the evidence need not be repeated at this point. Since the publi- * The crystals were small but well-developed. + This Journal, xxi, 108-108, 1906. to Calcium and Magnesium Metasilicates. 29 cation of the above paper, however, better facilities for refrac- tive index determinations have been acquired and the refractive indices of the two compounds have been redetermined. The measurements were made on polished plates of the crystalline ageregate, experience having taught that even under such conditions it is possible to determine y and a in sodium light with the reducing attachment of the Abbé-Pulfrich total refractometer, while 8 can also be ascertained if the individual grains are sufficiently large. For wollastonite the new values are, Yna = 1°632+-002; By, = 1°628+:008; ay, = 1:616 + 002; y—a = 016, y—8B = (004, B—a ='012. The refractive indices of pseudo-wollastonite are : yy,=1°650+:002; ay, =1:609+008 ; birefringence y—a = 041. The birefringence of both wollas- tonite and pseudo-wollastonite was furthermore checked by direct measurement in the thin section; y—a for wollastonite being 014 and for pseudo-wollastonite -043.* Magnesium Metasilicate—Like the calcium metasilicate, this compound has also been described in a special paper in which the optical characteristics are considered together with the other properties. Four different forms or phases were there mentioned bearing monotropic relations to each other, the monoclinic Mg-pyroxene being the one stable form. In the course of the past winter, however, still another phase has been discovered, orthorhombic in sy mmetry and in general aspect and development not unlike that of olivine erystals. TABLE V. No. Letter Symbol Miller 0) p 1 Exe) 0 001 py 2° 00’ 2 a 0 0 100 90° 00 [9052.00 3 b On 010 0 00 <6 4 m oe 110 44 04 se 5 Ni oo 2 120 Do. ON oy 6 Gets} oo 250 17 756 i 7 k (?) 3.0 310 70 44 . 8 no (2) 20 210 66 54 9 s 11 111 AB 1X0) 88 58 10 é 12 1a) Bite BIS yeaa a Tt p 10 101 90 00 29 - 09 b2: 0 1 111 46 48 AQ Ot 13 Z 12 12h 28; 30 ey ylhO) 14 ra) 10 103 90 00 Fi -455 15 (?) Aes 103 90 00 ye * Opportunity may here be improved to correct several of the optical data in the paper on the Lime-Silica Series of Minerals (this Jour., xxii, 293-302, 1906). At top line of p. 297 read: a= 1°609+ 008, y = 1°620+ 002, instead of the values given; on p. 298, 11 lines from the top, «= 1°534+°002 and w = 175444 002; on p. 299, 8 lines from bottom, 1°585 and 1°621; and 2 lines from bottom, a = 1590; on last line, p. 299, read -019 instead of ‘020, 30 Allen, etc.—Diopside and its Relations The optical data of the monoclinic Mg-pyroxene form given in the above article can now be supplemented by more accurate figures in several instances; and at the same time several errors in the crystallographic data can be rectified. The §8-MgSiO, is monoclinic and the observed form and measured angles are listed in Table V above.* The reflexion signals from many of the faces were multiple and wide variations in the angles occur. The best average ratios from these values are about fo ='d8 g,=°60 e=-046 w= 87°26; or G50 Gi NOS i060: 3998, = 8 ae ee ~ values which are closely similar to those for enstatite but less so for diopside. The variations are not such, however, as to preclude isomorphic relations between the two. The plane of the optic axes les normal to the plane of symmetry and not in the plane of symmetry as in most pyroxenest ; the bisectrix c is inclined to the vertical axis c, 21°8°. The optic axial angle was measured on the universal stage and by means of the two screw micrometer ocular. Care was taken to select favorable sections and the probable error in each case was not large. The average of all good determinations by both methods is 2V = 53°5°+1°, or 2E = 96°. The overlapping of the twin- ning lamellae often causes abnormal variations in this optic axial angle and it proved a difficult matter to find suitable sections. Etch figures on the cleavage face were also obtained and will be considered later, together with the etch figures of the other members of this series. The a-Mg8i0,, to which reference has already been made, crystallizes readily and is obtained by quenching the crystal- lized melt from temperatures above 1365° to prevent its inversion to the 8-form. Once obtained it can be held for apparently an indefinite period at ordinary temperatures with- out inversion to the more stable 8-form. The erystals are orthorhombic in symmetry and in certain positions bear strong resemblance to the characteristic crystal habit of olivine. On the surface of a melt held at 1510° and then chilled rapidly, several crystals, water-clear and sharply bound erystallographi- cally, occurred, and three of them (1x °5 x:2™™) were measured * Compare with Table II on page 598, vol. xxii, 1906, this Journal, in which several letters were unfortunately transposed, although the relations are correctly represented in the gnomonic projection plat on the same page. + The relations of the different pyroxenes, particularly of the magnesium iron group, have been recently discussed in an interesting paper by W. Wahl (Die Enstatit-augite, Tschermak’s Miner. Petrogr. Mittheil., xxvi, 1-181, 1907), who proposes the name clino-enstatite for the 6-MgSiO; or magnesium pyroxene. The suggestion is a good one and may well be adopted, the two latter terms being long and cumbersome. to Calcium and Magnesium Metasilicates. 31 on the goniometer. The reflexion signals were not of the best and the angles of the table can be considered only approxi- mately correct, an error of +15’ being easily possible. TaBLE VI.* No. Letter Miller Symbol o p 1 b 010 Qce 4405037 90°00’ 2 mM 110 oe) 40 08 90 00 3 k 011 O1 0 O1 25 09 From the angles the crystallographic constants can be eal- culated : Dee = 0-40 G.,— O40 or G0 26 = VAS: 1: O47. The crystals are often tabular and prismatic in shape after 010 as indicated in fig. 10. In other cases the prism zone is less prominent and the crystals are of equant development. The forms 6, m, and k_ Fie. 10. were observed on all three crystals. Cleavage after 100, good. The plane of the optic axes is the cleavage plane 100 and the acute bisectrix isc. The optical orien- tation is, therefore,a@ = 6; 6=c; and optical char- acter +. The refractive indices were determined by the immersion method in refractive liquids; a = 1-641 + 008; B=1-648 +003; y = 16634-0083; y—a=022; y—B=015; B-—a=-007. The birefringence y—8 = -016 was furthermore measured directly on a tabular erystal 0°182™" thick by use of the Babinet compensator. The optic axial angle is large and was measured with the two-screw micrometer ocular on two sections showing an optic axis in the field of vision. The average of the two values thus obtained (2V = 59°5° and 61:0°) is about 2V = 60°3° and 2K = 111°. The axial dispersion is fairly strong, 2 Vp > 2V». * The angles in the table are the averages of the different values obtained. These measurements were made on January 17, 1906, and since that time no suitable crystals for goniometric measurement have again been observed. Although the original notes stated definitely that these ‘‘ crystal angles do not coincide with those of enstatite’’ while ‘‘the optical relations do not correspond with those ofolivine,” and this same form was observed at that time in at least seven different preparations, its importance was not realized and its presence was ascribed to impurity. In later experiments practically no chilling was done and not until the thermal data indicated to Dr. A. L. Day the presence of a high-temperature phase, enantiotropic to the first, were quenching experiments again resumed and with them the true signi- ficance of the a-MgSiO; became apparent. 32 Allen, ete.—Diopside and its Relations In several of the larger crystals of the a-Me@SiO, a character- istic arrangement of inclusions and lines of growth was observed and strongly resembled the hourglass structure of certain pyroxenes, the hourglass portions of each crystal showing abnormal interference phenomena, due either to incipient changes into the 8-form or to peculiar intergrowths or possibly, but not probably, to strain phenomena. The a-form is readily distinguished from the 6-form by its lack of polysynthetic twinning, parallel extinction and stronger birefringence ; from olivine and enstatite by its cleavage and the position of the optic axial plane relative to the cleavage. It is of interest to note that the a-MgSiO,, which is unstable below 1865° and cannot be obtained except under very special conditions, has not been observed in nature, thus establishing, as in the case of pseudo-wollastonite, a high temperature limit for the formation of certain minerals. . Dropside.— This third compound of the series is an excellent erystallizer and can be formed in a number of different ways and at different temperatures. The best crystals were obtained by heating glass of the composition CaMgSi,O, in a flux of CaCl, in an atmosphere of dry HCl at 1000° for one week. The crystals varied in size up to 2™™ in diameter, were water-clear and of simple crystallographic habit. Three crystals were measured on the goniometer with reducing attachment. The reflexion signals obtained, were not of the best and the values of Table VII are the averages of the observed angles. A number of other crystals were selected and mounted on the goniometer, but the reflexion signals from their faces were often multiple and unsatisfactory, and not suited to improve the results already obtained from the three measured crystals. Tasie VII. Artificial Diopside ° Natural Diopside No. Letter Miller Symbol Q p 0) p ik b 010 0 00 90 01 0 00 90 00 2 mM ie) AB 30 90 40 43 33 90 00 3 S Tli : =I 94 51 Ba) Os 25 O7 33 04 4 x LD —2 35 a2 55 20 Bo 22 55.19 5 X(?) 331 —3 39 17 66 17 38 19 66 04 For the sake of comparison, the angular values @ and p for the same forms on natural diopside (Goldschmidt, Winkelta- bellen, p. 288) are included in this table. From these angles the average value of p, = 539; ¢, = 568; ¢ = -276, and w = 73° 59’; ora@:6:¢= 1:096:1%7 7591. For mnatuxalidigpemes p, = 05390; g, = 0:5670; e.= 02781; = (eave ee to Calcium and Magnesium Metasilicates. 33 a@:b:¢ =1:0934:1:05894. Both the angular values and the calculated crystallographic constants prove the close resem- blance of the artificial diopside crystals to the natural mineral, the differences observed being within the limits of error possible with the quality of reflection signals Rie Ui obtained from the artificial crystals. OS he Except for the form 2, which was observed only once, the crystal habit is simple and requires no comment. ‘Twinning after 100 is common and one of the three erystais measured was thus twinned, the twinning plane dividing the crystals into two nearly equal halves. Polysynthetic twinning after 100, however, occurred only rarely and is not characteristic. Prismatic cleavage after 110 is good; in diopside crystallites from the melt indications of a parting after a dome or basal pinacoid face at an angle of about 66° with the prismatic cleavage cracks were also recorded. The refractive indices were measured on polished plates of the crystalline material on the total refractometer in sodium light : Yna = 1°694 + 002; By, = 1°671 + *002; ay, = 1°664 + -002 ae 0S 028 Ga — OT Direct determinations of the birefringence were also made in the thin sections with the result: y—a = -030 + ‘062 (average of three measurements on good sections). The optic axial angle was measured on a number of different sections both with the universal stage and with the two-screw micrometer ocular. The average of four good determinations is: 2V = 59°32-1°; 2H = 114°.. The optical axial dispersion is weak, 2Vp>2V,. The plane of the optic axes is the plane of symmetry (010). Extinction angles were measured both on the clinopinacoid aoa the prism tace 110. On 010¢:¢= —38°°5 241°. On 110 e:¢c=—32°9+1°. The position of total extinction was ascertained in each case by use of the new bi-quartz wedge plate* and the values should be correct within 1°. Extinction angles were also measured for different faces in the prism zone. Suitable crystals, held in a specially constructed device,t were immersed in a liquid of the refractive index 8 and the extinction angle read for different angles of revolution of the crystal from its position of zero extinction when the ortho- pinacoid is normal to the axis of the microscope. * This Journal, xxvi, 377-379, 1908. + This Journal, xxvi, 388, 1908. Am. Jour. Sc1.—Fourts Series, Vou. X XVII, No. 157.—January, 1909. 9 2 34 Allen, etc.—Dvopside and tts Relations o* i E, Ob 0° On Os —13° —12°°5 20> —20°'9 —21°°7 30° —27°:] —27°°9 40° —32°°2 —31°°9 SIO) — 32°°9 —32°°5 510) © —34°°3 —34°°6 60° —35°°5 —36°°4 FO; —387°2 —37°°6 80° —38°°5 —38°°3 90° —38°°5 —38°°5 * d=angle of prism face with orthopinacoid 100. These figures indicate that for the first 40° from the ortho- pinacoid the extinction angle rises very rapidly while for faces near the clinopinacoid the variations are very slight. For the sake of comparison the theoretical valnes of the extinction angles indicated by the Michel-Lévy formula* are listed under column E.. From the melt diopside crystallizes readily, usually in the form of radiating prismatic individuals intricately intergrown and overlapping. A characteristic microscopic feature is the presence of fine bubble-like inclusions or cavities throughout the crystallized mass. These cavities are either tubular in shape and parallel in a general way the prismatic elongations of the crystallites; or they appear cutting across the sections in an irregular way not unlike the cavities in a section of worm-eaten wood. ‘The cavities are probably due to the shrinkage accompanying the crystallization of diopside from the silicate melt.—Such air spaces in the crystals from CaCl, fluxes were only rarely observed and are not characteristic of the same. The Intermediate Compositions.—In studying the prepara- tions of this series intermediate in composition between the compounds, the microscopic analysis has been directed along two principal lines: (1) To ascertain whether or not the prod- uct is homogeneous ; (2) to determine as accurately as pos- sible the optic properties of the one or more components in each preparation. Experience with both thermal and optical data has shown that in certain instances limits of homogeneity cannot be detected within one or two per cent optically and the optical determinations of the limits of solid solution in this series given below may easily be in error therefore one or two per cent. * Les Mineraux des Roches, p. 11, 1888. In this formula the following values Nee used: V=29"'6, -y=0°, ext. angle=358 -)/oriu—6 (0) vem do Ds , to Calcium and Magnesium Metasilicates. 35 When out of the melt of a readily crystallizing substance, minute quantities of a second substance crystallize, they are usually so completely hidden in the mass of the first crystals that the process of finding them microscopically is not unlike that of “finding the needle in a haystack,” particularly when the optical pr operties of the two substanees are closely similar. It has been found by experience that the best method for detecting inhomogeneity is to immerse the powdered material (finely divided by tapping the substance in a mortar) in a liquid of the refractive index of the predominating substance ; in this the minute particles of the second substance can be seen at a glance, if its refractive index be different from that of the first. For this purpose, a set of refractive liquids of indices ranging from 1:450 to 1-790 has been used, the refrac- tive index of each successive liquid differing from the forego- ing by -005. The refractive indices of these liquids were determined directly on an Abbé-Pulfrich total refractometer and their constancy checked every three months at least.* The liquids are kept in small dropping bottles (80° capacity) with ground glass stopper and ground glass cap, and the refractive indices of the liquids change either very slightly or not at all in three months. In ascertaining the different optic properties of the members of this series, the following methods have been found most serviceable and seem best adapted to work of this character: Refractive indices were measured by use of refractive liquids after the immersion method of Schroeder van der Kolk. Wherever possible, especially on homogeneous preparations, * The following is the list of liquids used in the preparation of this set. (On an average the change in refractive index of a liquid is about ‘001 for a change of 3° ©. in temperature.) Refractive Index. Liquids used. 1-450 to 1°-465 Mixtures of chloroform and carbontetrachloride. 1-470 to 1°495 Mixtures of turpentine and xylol. 1°500 to 1°505 Mixtures of xylol and monochlorated benzene. 1°510 Aethyliodide. 1°515 to 1:°520 Mixtures of cedar oil and clove oil. 1520 Monochlorated benzene. 1°530 Mixtures of cedar oil and clove oil. 1°555 Mixture of aethylbromide and monochlorated benzene. 1°540 to 1550 Mixtures of clove oil and cinnamic aldehyde. 1°555 Nitro-benzol. 1-560 Benzene monobromated. 1°565 to 1615 Mixtures of clove oil and cinnamic aldehyde. 1°620 to 1635 Mixtures of benzene mono-chlorated and a-monochlorated naphthaline. 1°640 to 1°655 Mixtures of a monochlorated naphthaline and a-mono- bromated naphthaline. 1°660 to 1-740 Mixtures of a-monobromated naphthaline and methylene iodide. 1°740 to 1°790 Mixture of methylene iodide and sulphur. 36 Allen, ete.—Diopside and its Relations the refractive indices were measured directly on the total refrac- tometer, experience having shown that with polished plates of the crystallized mass of substance the y and a limiting refrac- tive index lines can usually be distinguished if the reducing attachment be used. In such cases where the maximal and minimal indices are determined from aggregates of erystals - rather than from one crystal, it is of course not possible to determine also the refractive index 8. Optic axial angles were determined by use of the two-screw micrometer ocular and also by the modified universal stage* of Fedorow. Extine- tion angle measurements were made with the aid of the bi- quartz wedge plate,t care being taken to select favorable sections in each case. Direct determinations of the birefrin- gence in the thin section or in flat crystal grains were accom- plished by measuring the thickness of the plate or grain with the micrometer screw of the microscope (model Fuess) and then ascertaining the path difference of the emerging waves by means of a Babinet compensator. By this method only a fair degree of accuracy can be obtained because of the Fie. -12: | | bok | BIMa SiO, lO : = | lige 0) 1G 20 50. 40 50 6D 10 30 * This Journal, xxiv, 317-869, 1907. + This Journal, xxvi, 377-879, 1908. to Calcium and Magnesium Metasilicates. 37 difficulty of determining the thickness of the plates accu- rately. This error was “reduced so far as possible by taking the average of a number of measurements of thickness on the same section and by grinding the sections thicker than usual. The optical data prove that wollastonite can take up in solid solution about 17 per cent of diopside, while pseudo-wollaston- ite can absorb only about 4 per cent of diopside in solid solution ; that in diopside only a small amount of the calcium metasil- icate, not over 5 per cent, can enter into solid solution, while mixed er ystals containing up to about 39 per cent of MeSiO, | in diopside can exist ; the maximal solid solution of diopside in B-MgSiO, is not oreat and does not exceed 5 per cent. These relations were ascertained both by observing the limit of homogeneity of the preparations and by observing the changes in the different optic constants of the prepar ations. In fig. 12 the optic constants are represented graphically and the limits of solid solution are indicated by the breaks in the eurves. The optical data from which these curves were drawn are included in the following table (V II]). Although every effort was ; made to reduce the probable error of the values listed in this table, the very nature of the mate- rial precluded accuracy of a very high order. The refractive indices given in the table may be considered exact within +°003 ; the direct determinations of birefringence within +°003, especially when checked by refractive index determi- nation ; the optic axial angles are not all of the same order of accuracy,—that of psendo-wollastonite being the least satisfac- tory, with 8-MgSiO, next; in general the probable error does Sei exceed 1"; the extinction angle determinations on 110 probably vary less than 1° from the true values. Table VIII as well as fig. 12 prove conclusively that diopside is a compound, and that the limits of solid solution for the different members of the series is that indicated above. Beginning with wollastonite, the refractive indices, the birefrin- gence and the optical angle of the pure compound increase with increasing admixture of MgSiO, up to about 8 per cent MgSiO,, after which the curves are practically horizontal, thus marking the limit of crystal miscibility with diopside. In the sections free diopside was observed first in the preparation containing 10 per cent MgSiO,.—For pseudo-wollastonite the refractive indices, the birefringence and the optic axial angle increase shghtly only up to about 2 per cent MgSiO,, and the exami- nation of the preparations proved that beyond this limit inho- mogeneity exists and diopside is present.—The limits of solid solution of CaSiO, in diopside were difficult to determine optic- ally with any devree of certainty. .The data indicate only slight solid solution, probably not below 45 per cent MgSiO,, or not over 2 2 per cent of calcium metasilicate. In the prepa- 38 Allen, etc.—Diopside and its Relations TaBLe VIII. | ea 5 | Resets 3 |Optical| Dis-| PARC Composition | | | =| axial | per-| Ae % MgSiO; |} @ | B | y |y—a*|y—aly—B\y—'lS | angie |sion eer ae | | [ anaras : | | st 110 | | O | 0 | Wollastonite ee /1°616 1°628/1-6382) -014 | 016) -004| -012 |—| 388°°8 |p> w ia 0 |Pseudo-wollastonite|/1°609) -. |1°650) -043 |-041; __)| __ |+] 75] _. Soe de bs [oben ie ele nt ae 2 Rr em paememmime (ho ear 3 | a (164 2be 2654 |; 043-1 04215 Soe ts al hee Ae ose 5 +c were ee pee AGT biases as sci 10°°5 ae stant 5 Wollastonite .-.--- | SO OO OR ee el 3 eke 7°95 a '1°620,1°630/1:634) -014 | -014/ -004) -010 |—| 41°°0 | __ Sees 7°95 |Pseudo-wollastomite| _-°| <2 | vei) 2 tS) oe) Se ee 10 |Wollastonite ----_- wa | ee Olses heres ae oe ol ee nae 10-74)“ Pe eee 28 | e bese enee a ie Pn Pn eee ire. BS on Dio psid eke saa serae nn ees ee enn ee meme N Cao) oes) Se 40 Be 1670) (1-694) 1024). ssc ok Sh eye oie ee lee ctas 44°5 ! eo ays ==} 22 | 0804 2 ee | eer ee ee a Peeler teres ee SS eae AGP) er 1-664 1°671'1-694| -030 | -030) -023) -007 | +) 59°°3 | __ | —82°-8 OMe she 11664) 2 |1°692). 22 1028) «2 2 le OS See nie i eae uae (1-662). 11°684) -027 | 022) 2 | 2s 5) Uae ee aa '1°660} __ |1°684) -024 |°024).02 2) >. 2/52) SG RS eer Gor anels sige, 1°654! > {17678} --022: |-024) oo) DAR OR eee eee 66:5 |“ ly oe 098 |) nol panel ee BS.a x wer na an re rime ei | me I, a | es ew Bate Oe: oe ie Be iy MA yo) ey oe Ohne Where wo fete hell dh ea | ol ea wi. * Se eee ce) s088 | 2S) 2s | Sle see SOr tary Bes Peat mere wef SSE a 2s sa ee aa OO pL OSS Sr Os ah wee oD pole bo ee =| cS) el Seat 97° .\B-MgSiOg = =2-.2527 (1-650) 2.2 /1°660) 22. | O90) e225) 6 225) 4. ee ees 98 | er Se Read (0 eal J sad se eel ooeg om eam bie 100 | eS 1:645|1°647)1°655| -009 | 010) 008) -002 | +| 53°°5 | _- ere 100. “ia-MeSiO3-2 22 22.28 '1°64111°648 1°663) __ 1-022) -015) 007 1+] 60°°3 [p> v Bes S * y—a in this column was determined directly by measurements on plates in the thin section. rations between 40 and 45 per cent peculiar phenomena were observed and no satisfactory tests of homogeneity could be made.—Between diopside and pure magnesium metasilicate mixed crystals extend from diopside up to about 66 or 67 per cent MgSiO, of the series. ‘The appearance of all prepa- rations between pure diopside (46°12 per cent MgSiO,) and 67 per cent MgSiO, is that of diopside in the thin section so far as the optic properties are concerned. The refractive indices, the birefringence, the extinction angles and the optic axial angles all decrease gradually but noticeably, and the sections appear homogeneous under the microscope except for the minute air spaces. The crystallized melt changes noticeably moreover in appearance from the large, bright and glistening to Calcium and Magnesium Metasilicates. 39 ageregates of diopside to dull, lusterless, white granular masses of much finer grain and higher MgSiO, content. Beyond the 68 per cent the preparations appear Inhomoge- neous, the 6-MgSiO, appearing in increasing amounts as its composition is approached. In the preparations ranging from 68 to 90 per cent MgSiO, in composition, 6-MgSiO, appears almost without exception intergrown with the diopside and usually oceupies the center of the large diopside sections. The 8-MgSiO, is invariably twinned polysynthetically after 100 and on sections approximately normal to the prism axis, the pris- matic cleavage lines can be seen cutting across both the diopside and the B-MgSi0,, thus indicating. the close crystallographic symmetry of the two compounds. In such sections the B-MgsSiO, is characterized by its weak birefringence and by the position of its optic axial plate parallel with the twinning lamellae, while for the enclosing diopside substance the optic “axial plane i is at right angles to the twinning lamellae.—The limit of crystal miscibility of diopside in B-MgSiO, is above 98 per cent MgSiO,, since preparations of that composition are clearly inhomoge. neous. ‘The optic properties of the 8-MgSiO, change slightly between 98 and 100 per cent MgSiO,, but only enough to indi- cate very slight solid solution, probably not over 2 per cent of diopside. Lich figures.—Proot of the fact of solid solution for composi- tions ranging from pure diopside to about 67 per cent MgSiO, was also gained by etching the erystals with hydrofluoric acid. At the present time isomorphism ; is a much discussed subject and its final definition has not yet been agreed upon. Emphasis has been placed on similarity of the crystal form of the two end members, on analogous chemical composition, on complete misci- bility, and on the fact that for some of the physical properties, as specific volumes, the properties of the intermediate mixtures are additive functions of those of the end members. This last assumption of Retgers has been questioned recently, * while the qualification of analogous chemical composition has long been considered unnecessary by certain investigators. Briefly stated, the tendency seems to exist for crystallizing substances to absorb, during the process of crystallization, large or small amounts of other material. The more closely similar the absorbed material is to the absorbing crystal in crystal structure, dimensions and tendencies, the greater the amount in general which can be thus taken up. In certain instances, the properties of two substances are so similar and their molec- ular volumes so nearly equal, that the solid solution or crystal miscibility extends from the one compound without break to the second, and the physical properties vary continuously throughout the series. In such a case of complete miscibility no doubt can existas to the isomorphic relations of the two end *B. Gossner, Zeitschr. Kryst., xliv, 417-519, 1908. 40) Allen, ete.—Diopside and its Relations members. But in case the crystal miscibility is incomplete or limited the term isomorphism has not yet been defined with adequate precision nor the criteria therefor developed with sufficient sharpness to permit one to state in every actual case whether or not isomorphism does exist. Itseems proper, how- ever, to speak of the two compounds in the first case as com- pletely isomorphous, while in other instances the isomorphism isincomplete or limited. In the case of incomplete isomorphism, criteria such as crystallographic similarity, additive character of certain physical properties in the intermediate mixtures, chem- ical analogy are then relied on to prove isomorphism. In the present series, the diopside and 8-MegSiO, are of the same crystal system and somewhat similar in crystallographic properties. Limited miscibility has been shown to exist and the physical properties prove that the two are incompletely’ isomorphous. This being the case, it is reasonable to suppose that their internal crystal structure is similar, that the distri- bution of the effective crystallographic forces is analogous. In the intermediate mixtures, therefore, the distribution of the forces is represented, approximately at least, by the resultants of the er ystallographie forces of the end members in their proper intensities. One of the best methods for studying the distribu- tion and relative intensity of crystallographic forces is by means of etch figures. On the above assumption, the etch figures of the intermediate members should be intermediate in character between those of the end members, diopside and 8-MgsSi0,.* After considerable experimentation on the conditions best suited to produce favorable results, both with respect to the etch figures and the handling and photographing of the exceed- ingly small crystals, this statement has been substantiated. The etch figures on 110 were produced by immersing cleavage pieces from the different preparations in hot commercial hydro- fluoric acid. (heated over a steam bath in a platinum crucible) for 40 seconds and then stopping the reaction by plunging the crystal into cold water. The crystal was then mounted on the condenser lens attachment of the universal stage} and examined in strong reflected are light and turned, until the proper cleavage face, 110, was normal to the axis of the mier oscope. The etch fioures on 110 thus obtained were not of equal size or develop- ment for the different members of the series. The largest and best developed etch figures are those of diopside (Plate I, photomicrographs a and 6), while the least favorable are those of B-MgSiO,, which are exceedingly difficult to obtain under * The value of etch figures in determining isomorphism has been strongly advocated by Retgers (Zeitschr. f. Phys.-Chem., xvi, 35, 1895) and notwith- standing the objections which have been raised to this criterion, it does apply in certain series. In the present case of limited isomorphism the eteh figures sustain the contention of Retgers. + This Journal, xxiv, p. 342, and fig. 7, p. 332, 1907. to Calecum and Magnesium Metasilicates. 41 any conditions and are excessively small. The photomicro- graphs (Plate I), a—/, illustrate the changes in the shape of the etch figures thus produced on 110 in preparations ranging from diopside to pure 86-MgSiO,. The etch figures on diopside (a and 6) are long spindle-shaped pits with an upper blunt termina- tion. On an average their length is four times the width and the angle a between the two sides at their point of junction at the lower extremity is about 18°. These etch pits are similar in every detail to those on 110 of natural diopside from Ala,* Piedmont. Etch pits on the face 010 were also cbserved and likewise resembled those on 010 of the natural mineral.—The etch pits on 110 of the preparation 50 per cent MgSiO, (c) are very similar to the figures on diopside, the angle a between the two sides at the lower extremity being slightly greater perhaps. On crystals of the composition 55 per cent MgSiO, (d) the etch pits are noticeably wider and the angle a has increased to about 35°. This angle a gradually increases until at the limit of solid solution it measures approximately 50°( 7). ‘The relation of the length of the etch pits to their width changes from about 4: 1 in diopside to 3: 1 in the 55 per cent and about 5:3 at the limit as _ represented by the etch figures of the 75 per cent preparation, which were chosen in place of those of the 67 per cent because of the sharper definition of the particular figures photographed. The transitional changes in the shape of the upper portion of the etch figures are also characteristic. The etch figures on the cleavage faces of 8-MgSiO, (e) are exceedingly small and triangular in shape; the angle a measures 55°—60° and the rela- . tion of length to width is about 3:2. Other details of the etch figures appear in Plate I and the evidence from all view- points tends to strengthen the assertion, that in this case of limited or incomplete isomorphism the character of the etch figures does change continuously with increasing MgSiO,, and. in the direction of the type of the etch figures of pure 8B-MgSiO,. It is of interest to note that the 6-MgSi0,, the low tempera- ture form, takes up very little if any diopside in solid solution. This may be due to the fact that the high temperature-, a-form, is orthorhombic and therefore would have less tendency to take up the diopside molecule. On the calcium side of diopside the erystal miscibility i in the series is very slight, diopside taking up only small amounts of the calcium metasilicate. Wollastonite, on the other hand, can absorb up to 17 per cent of diopside and still remain homo- geneous, whereas pseudo-wol:astonite takes only 4 per cent at most of diopside in solid solution. No satisfactory explanation has been found to account for these differences in the behavior of the different compounds of this series. *Compare R. A. Daly, Proc. Amer. Acad. of Arts and Sciences, xxxiv, 373-428, pl. iv, No. 18, 1899. 42 Allen, ete.—Diopsidle and tts Relations In Part I of this paper, the fact of eutectic mixtures and its bearing on the present problem are shown to be of prime importance. In the case of alloys eutectic textures are definitely recognized and it is natural to expect such textures in silicate melts. In the latter, however, power and rapidity of crystallization, combined with viscosity, frequent absence of stable equilibrium, and other factors, tend usually to veil effectively such textures which might otherwise develop. Indications of probable eutectic textures were occasionally recorded in this series, but as a rule the crystallization appar- ently takes place so rapidly with strong undercooling that normal, theoretical conditions of equilibrium do not exist. — It is also of interest to note that throughout this series the melts of the pure compounds are, as a rule, of coarser grain than the intermediate compositions and of more vitreous luster. The intermediate mixtures frequently resemble porce- lain in appearance. This change in aspect undoubtedly results from the decrease in granularity and lack of continuity of the single crystallites. The inversion of the a- and B-MgSiO,.—With pure MgS8i0,- melts the thermal data show practically no heat effect at the . temperature of inversion of the §- into the a-form and vice - versa, and only after the admixture of several per cent of diopside does the thermal effect produced by the inversion appear. The yuenching experiments of Dr. A. L. Day, how- ever, proved definitely that the a-MgSiO, did exist, and _attempts were then made to fix the temperature of inversion by use of a specially constructed thermal microscope.* (Fig. 13, a and 6.) * Constructed in the workshop of the Geophysical Laboratory after plans by Dr. Arthur L. Day and the writer. The details of construction of the electric resistance furnace are given in fig. 186, two important features of which were suggested by Dr. Day, namely, the enclosing of the whole in a suitable water jacket and the splitting of the thermoelement wires to serve as a support for the preparations. By this latter device the purity and temperature of the preparations even at high temperatures is insured. The microscope is fitted with revolvable nicols ; at the base of the furnace there is a thin metal slide, As, by means of which part or all of the field can be shaded and the characteristics of the light emitted and transmitted by the body studied with respect to effects of polarization. A plate at high tem- peratures may become often self-luminous and it is then necessary to adopt special devices to detect transmitted polarized light and with this end in view the optical system of the microscope has been arranged. With it, also, the character of the emitted light alone can be examined with respect to polarization effects if such exist. At high temperatures the white heat of the furnace tends to veil the interference phenomena unless the transmitted light be of greater intensity, and this condition has been met by using an electric arc as source of light. With this furnace the birefringence of quartz has been measured up to 1300° and it is proposed to study the optical changes in several minerals at different temperatures in this way.—Tempera- ture readings are made either roughly on a direct reading Siemens and Halske voltmeter or accurately by use of the potentiometer.—The water jacketing of the furnace permits its use on any microscope in which the distance between the stage and the objective can be made great enough, the optical system remaining thereby unchanged. to Calcium and Magnesium Metasilicates. 43 Fig. 13, a. 44 Allen, ete.— Diopside and its Relations Fics. 18, a and 6.--Microscope equipped with electric resistance furnace. With the exception of the base and the upper tube, which were taken from « Fuess universal stage microscope, this thermal microscope was constructed in the workshop of the Geophysicai Laboratory. The microscope is fitted with revolvable nicols and a low power 38-inch objective. The furnace rests directly on the stage of the microscope and can be revolved through small angles. Its different parts are shown in cross section in fig. 186 (one-half actuul size). The water jacket consists of three parts; We, base; D, side cylinder, and W;, cap. Each of these parts is complete in itself and by means of rubber tubing (fig. 15a) the water is made to pass through We, then D and finally W,;. At G in both W, and We glass plates are introduced and allow light rays to be transmitted without permitting the heat to reach the objective and lower condenser system. The circulating water is suffi- cient to keep these plates cool. In the first experiments air bubbles from the water collected between the plates and seriously disturbed. the clearness of vision. This difficulty was overcome by means of rubber plungers fast- ened to A, and A, (fig. 15) which could be passed back and forth in front of the plates and the bubbles brushed aside. By means of the rod A; with its attached brass plate, transmitted light from any part of the field can be shut off and the effects of emitted light alone studied. The furnace itself con- sists of a tube F (fig. 136) 7:5" long, 4:5“ outside diameter and 1™ inside diameter, wound on the inside with fine platinum wire ‘30™™ diameter. The thermoelement wires are supported by the porcelain tube T, which rests directly on the asbestos paper covering the upper plate of W2. The thermo- element wires are introduced into the furnace at M (fig. 18a) and the furnace wires on the opposite side of the microscope. The sides of the furnace, F, are surrounded with magnesia powder and the ends capped with asbestos paper, to prevent loss of heat from radiation so far as possible. Better results were obtained by another method, in which single,water-clear crystals of 8B-MgSi0, (about -2x° 21m) were mounted in cedar-oil on the universal stage and turned until the clinopinacoid was normal to the line of vision and the twinning planes appeared as sharp lines. After photographing in this position (magnification 100 diameters) the crystal was placed in a specially prepared platinum basket and heated in an electric resistance furnace to a specified temperature, either above or below that of the 6-MgSiO, inversion. After cool- ing, the crystal was again photographed under precisely the same conditions as before heating. The study of a long series of negatives prepared in this way has brought out several interesting points: In the inversion of a single crystal of 8-MgSiO, to the a-form, no great volume change is involved nor eyen a great redistribution of the molecules. This is evident from the fact that after reversion from the a- to the 8-MgSi0O, the original crystal is intact and its faces still fairly sharp. Twinning planes are still present though usually in different positions, each lamella extending the entire length of the crystal as before heating. On such ~paramorphic change, inversion into one form and reversion to the original, it might be expected that, as in crystal aggregates for med by precipita- tion, many crystal nuclei would be formed,* and that on reversion each one of the new nuclei would produce at least one separate individual of the original form, with the result *This actually happens on- the inversion of wollastonite into pseudo- wollastonite. This Journal, xxi, 107, 1906. to Calcium and Magnesium Metasilicates. 45 that instead of a single crystal or a regularly twinned crystal, the aggregate of irreoularly oriented individuals would result. In case, however, the molecular redistribution was slight, the inversion might preceed in regular fashion throughout the entire crystal and the effect of inversion and reversion be chiefiy one of shifting of the ever present twinning lamellae. And this is the exact state of change in the 8-MgSi0O, crystals. Rarely the subdivision of a erystal into several irregularly bounded parts was noted and usually only the shifting of the lamellae. It was also of interest to observe that occasionally a shifting of the twinning lamellae took place in crystals heated to temperatures slightly below the inversion point. Because of this property, no decisive determinations of the inversion point could be made and recourse was taken to sudden chilling experiments——the preparations being first melted, the tempera- ture then lowered and kept at a specified point for one hour, aiter which the preparation was dropped into cold water and chilled almost instantly. The a-MgSiO, thus obtained clearly showed the effect of incipient change even under these condi- tions, the major part of the powder being ful] of minute dustlike particles or cavities and as a result was semi- or sub- transparent, and only now and then were clear portions of the a-form observed. Whenever the a-MgSi0, was held at tem- peratures slightly below the inversion point and then quenched, the entire preparation consisted essentially of the twinned 8-form alone in clear transparent individuals, the dusty effect as well as the a-MgSi0, aggregates having practically disap- Bo. peared except for an occasional clear crystal of the same. Summary. 1. The end members of the system CaSiO,-MgSiO, both exhibit enantiotropy. The inversion point in the former is about 1190°. The a-form, pseudo-wollastonite, is unknown in nature. The #-form is the mineral wollastonite. The 8-form of magnesium silicate is the magnesian pyroxene occur- ring in meteorites and in intergrowths with enstatite and has recently been called clino-enstatite.* At about 1865° it is transformed into an orthorhombic form quite distinct from enstatite and unknown in nature. 2. Only one stable compound appears, viz., CaSi0,.Me¢Si0,, identical with diopside. It melts at 1380° and has a specific gravity of 3°275. It was obtained in well-formed, measurable crystals extremely pure, when erystallized from molten calcium fe A eutectic occurs between diopside and pseudo-wollas- eet at the composition 60 per cent diopside: 40 per cent calcium silicate. [t melts at 1348°. A second eutectic occurs at about 68 per cent MgSiO,: 32 per cent CaSiO,. It is com-- *W. Wahl, Die Enstatit-augite, Tschermak’s Mitth., xxvi, 1-131, 1907. 46 Allen, ete.—Diopside and its Relations posed of about 95°5 per cent of a mix-crystal containing about 62°5 per cent of diopside, 37°5 per cent magnesium silicate, and 4°5 per cent a-MgSi0,. Its melting temperature is 1375°. Microscopically eutectic textures were observed rarely if at all. 4. Six solid solutions appear in this system. Only two of them contain more than three or four per cent of the lesser component, and only these will be mentioned here. a. B-calcium silicate (wollastonite) forms a saturated solution of wollastonite containing about 17 per cent diopside (8 per cent - MeSsiO,): 83 per cent CaSiO,, when crystallization takes place in the neighborhood of 1050°, 1. e., wollastonite is capable of dissolving about 93720 ber cent of its own weight. ‘This series of solutions is interesting from the fact that the inversion point of pure calcium silicate (1190°) appears to be raised by the addi- tion of MgSi0,, up to 100° in the most concentrated solutions. This is probably largely, if not wholly, an apparent rise in the inversion point due to viscosity, for, as is well known, an inver- sion point should be raised only when the concentration of the solution below the point is greater than that above, while here there is a rise in the weaker solutions which suffer no change in concentration when they invert. Again, the concentration of solutions just below the inversion point cannot be determined with accuracy on account of the difficulty of establishing an equilibrium in solid silicate solutions. b. Diopside dissolves about 60 per cent of its own weight, forming a solution which contains 66°5 per cent MgSiO, : 33°5 per cent CaSiO,. This saturated solution is very similar to diopside in all its properties. Its melting point is only 3° lower (i. e., the maximum heat absorption falls there, the melting interval is unknown). The specific gravity changes very little; the optic data show slight but noticeable changes: the refractive indices, the birefringence, the optic axial angle and the extinction angles all falling continuously with the addition of MgSiO, from diopside up to the limit of solid solution at 66°5 per cent MgSi0O.,. 5. In the series of limited solid solution between diopside and clino-enstatite, the effect of the addition of MgSiO, to diopside 1s, furthermore, clearly shown by etch fioures on the prismatic cleavage faces. On passing from diopside to the limit of solid solution at about 66°5 per cent MgSiO,, the shape of the etch pits changes gradually, their character, on preparations of intermediate composition, being intermediate between those of the two compounds, diopside and pure 8-MgSi0O,, thus proving that actual solid solution does exist in the series, and that the effects of the end members are felt crystallographically in the solid solutions of the same.—For the observation, under the microscope, of changes which take place in substances at high temperatures, a special micro- to Calcium and Magnesium Metasilicates. 47 scope, fitted with electric resistance furnace, fig. 13a, has been constructed and found useful in the study of these etch pits. 6. The specific-volume curve consists of three well-defined branches, the first of which is the locus of the volumes of mechanical mixtures of pseudo-wollastonite (a-CaSiO,) and diopside; the second, that of the solid solutions of magnesian pyroxene (8-MeSiO,) in diopside; and the third the locus of the volumes of mixtures of saturated mix-crystals just men- tioned, and the free magnesian pyroxene. The volume of the solid solutions is greater than the sum of the constituent volumes. There is a sharp minimum on the curve at the composition of diopside CaSi0,.MgSiO,. On account of the _ presence of minute bubbles in the crystals and the compara- tively small difference between the specific gravity of diopside and that of the magnesian pyroxene, the critical points on the curve are several per cent in error. 7. A method for the more accurate determmation of the composition eutectics is described; also a method for the approximate location of inversion points in inert substances. The accidental variations between different determinations of the melting point of a sharp melting silicate seldom amount to 1° up to 1500°. This is the accuracy available for compara- tive measurements. The absolute accuracy of a determina- tion is less than this on account of the present limitations of the absolute scale. The authors wish to express to Dr. Arthur L. Day their hearty thanks for valuable assistance in connection with the study of the a-magnesium silicate. Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C., July 10, 1908. 48 Gilbert—The California Earthquake. Art. Il.—The California Karthquake of 1906 ;* by G. K. GILBERT. TureeE days after the California earthquake of April 18, 1906, Governor Pardee appointed a commission for its scien- tific investigation. No funds were at his disposal to defray the expenses, but provision was made later by the Carnegie Insti- tution, and the Institution is publishing the reports. Volume Pm two parts with atlas, has recently appeared, and a second volume is to follow. Volume Lis by Andrew C. Lawson, chairman of the com- mission, and includes contributions from a large number of collaborators. After an introductory account of the geology and morphology of the Coast Ranges, it treats at length of the physiographic. features and physical changes associated with the earthquake, of the distribution of intensity, and of the directions of vibratory motion. The marine phenomena, the composition of the main shock, the sequence of after shocks, and various minor topies are presented, and account 1s given of earlier severe earthquakes in the same region. The earthquake was of the tectonic class, and was occasioned by a slipping on the plane of an old fault. The fault outcrops at the surface, and there was a visible displacement of consid- erable amount. The line of outcrop trends NW.—SE., and the fault plane is vertical. There was, however, very little vertical displacement, the differential movement being almost wholly horizontal. The country adjacent to the fault on the SW. side moved bodily toward the NW., and the country on the NE. side moved toward the SE. The changes did not tend to increase the height of a mountain or the depth of a valley but merely to distort the land horizontally. The amount of displacement was measured in two ways, (1) by observation of the dislocation of roads, fences, etc , traversed by the fault, (2) by the remeasurement of a net of triangulation previously made by the Coast Survey. Fences and roads were usually offset from 8 to 15 feet, and the results from triangulation showed relative dislocation of about the same amount for * The California Earthquake of April 18,1906. Report of the State Harth- quake Investigation Commission. In two volumes and atlas. By Andrew C. Lawson, chairman, in collaboration with G. K. Gilbert, H. F. Reid, J. C. Branner, H. W. Fairbanks, H. O. Wood, J. F. Hayford and A. L. Baldwin, F. Omori, A. O. Leuschner, George Davidson, F. HE. Matthes, R. Anderson, G. D. Louderback, R. S. Holway, A. S. Eakle, R. Crandall, G. F. Hoffman, G. A. Warring, E. Hughes, F. J. Rogers, A. Baird, and many others. Vol. I, pp. xviii + 461, 146 pls. Atlas, 25 maps, 15 pls. seismograms. Washireton, D. C., 1908. (Published by the Carnegie Institution of Wash- ington.) Gilbert—The California Earthquake. 49 points near the fault line. For points at greater distance the changes were less. The discussion of the data, by J. F. Hay- ford and A. L. Baldwin, led to the conclusion that’ the absolute movement was greater west of the fault than east of it, and in both directions diminished with distance from the fault, the dimi- nution being most rapid in the immediate vicinity of the fault. This: ear thquake is practically unique, among the small group that have been broadly studied, in that the stress couple to which the fault may be referred lay in the horizontal plane. The main associated distortions were distortions in ground plan, with little vertical complication. They were, therefore, exceptionally adapted for measurement by the method of triangulation, and the results actually obtained are more syste- matic than any previous results of the same character. It is, therefore, peculiarly unfortunate that they were qualified by a lack of chr onologic unity in the trigonometric surveys preceding the fault, which were strung along through several decades. This fact made it impossible to discriminate between deformation at the time of rupture and progressive deforma- tion during accumulation of strain before rupture; and if progressive deformation took place before rupture, the pre- cision of the adjusted triangulation was thereby impaired. Nevertheless the results invite the careful attention of geophys- icists. To the reviewer the distribution of dislocation, and especially the existence close to the fault, on each side, of a belt of maximum distortion, seems clearly not that which would obtain if the fault passed completely through a solid crust to a liquid substratum. And it appears also that, on the assumption of continuous solidity from the surface downward, the geodetic results might yield to adequate analytic treatment a conception of the order of magnitude of the vertical distance to which the fault penetrated. The surface outcrop of the fault was definitely traced from San Juan to Point Arena, a distance of 190 miles. At Point Arena it passes under the sea, and there is doubt as to its further course. A fault made at the same time on a more northerly part of the coast may be its continuation, after inflection, or may be on an independent line; but in either ease the total length of dislocation was about 270 miles. At all points the, fault foilows a peculiar topographic feature to which the name San Andreas rift was given; but the rift is more extensive than the fault of 1906. having feed traced to the Salton basin, several hundred miles southeast of San Juan. In its larger expression the rift is a trough, a trough coin- ciding in general trend with the Coast Ranges, but crossing various mountain ridges obliquely, or even following their crests. Am. Jour. Sci.—FourtH SERIES, Vou. XXVII, No. 157.—January, 1909. 4 50 Gibert—The California Earthquake. In detail it comprises many small ridges and hollows, approxi- mately parallel but otherwise irregularly disposed, and evi- dently caused by splintery dislocation. Streams zigzag more or less about the ridges, and the hollows contain many small ponds and marshes. There are reports of long cracks which appeared in different parts of the rift in connection with various earthquakes of the last century, and it is inferred that each of these cracks was the surface expression of a fault-slip similar to that of 1906. It is further inferred that the rift as a whole marks the outcrop of a long fault or fault zone, separating two crustal tracts which are slowly moving past one another, with eradual accumulation of strain and stress, and occasional relief by local sipping when the stress at some point overpowers the adhesion on the fault plane. The physiography of the rift is illustrated by numerous excellent photographs, and by a local. contour map by F. E. Matthes. Although the rift has been mentioned in various writings of earher date, its description in this volume practically adds a type of surface configuration to physiographie science. In the discussion of the intensity of the shock, a distinction is recognized between the elastic wave propagated from the origin through the crust, with gradually diminishing magnitude, and the phenomena of emergence, conditioned by the nature of the surface formation. The intensity observed at the surface, and expressed chiefly by damage to buildings and other struc- tures, is called ‘apparent intensity,” and this only is mapped. The general map shows a long narrow belt of high intensity, fol- lowing the fault, with peninsulas and outlying islands where destructive effect was enhanced by the presence of incoherent formations; but this elongation is less characteristic of the lines limiting the areas of low intensity. The outer line, touching the most remote points of sensible tremor, traverses southern Oregon, central Nevada and southern California. In view of the ideas recently advanced by W. H. Hobbs, there is a careful review of the relation of local intensity to the known major faults of the region, about forty in number. In three cases it was thought possible that some portion of. the movement of dislocation was diverted from the main (San Andreas) fault to the planes of intersecting faults. A special intensity map of San Francisco, by H. O. Wood, shows with ereat detail the grades of violence; and its comparison with a geologic map brings out forcibly the intimate relation between effective intensity and the underlying formation. The subject is further elucidated by the report of an experi- mental study by I. J. Rogers. By mechanical arrangements similar to those employed by the Japanese commission in inves- tigating the principles of earthquake-proof construction, har- Gilbert—The California Larthquake. 51 monic horizontal motion was given to an open box containing some loose material such as sand. A block resting on and anchored to the upper part of the sand, so as to share its motion, was found not to have harmonic motion, but motion of a dis- tinet type which varied with the conditions of the experiment. Under certain conditions the amplitude of its motion was greater than that of the motion of the box, and its maximum acceleration—the factor corresponding to earthquake inten- sity—very much greater. These novel experiments are not only valuable in their immediate results, but of signal import- ance as indicating a line of study which should develop a com- plete theory of the phenomena of the emergence of earthquake waves. The marine phenomena were in accord with the terrestial in that they indicated no bodily movements of the ground except in a horizontal sense. Vessels at sea experienced a shock; there were boilings of water near the shore; a small selche was started in San Francisco bay; a wave several feet high washed the east shore of Tomales bay, a narrow sheet of water traversed by the fault; but there was no great sea wave such as accompany vertical dislocations of the ocean bed. The main shock, which was of about one minute duration, was reported by many observers as consisting of two parts, or having two maxima, but by others as continuous. Consider- ing the improbability that movement was synchronous and similar over the entire plane of rupture, it is to be assumed that the vibration had different characters at different places, but the observations are not discussed with reference to geo- graphic distribution. There are many records of preceding or accompanying sounds, all of low pitch. The after shocks were of normal character, diminishing with time in frequency and average strength, and continuing for at least ten months. The report enumerates more than 100 in the first 24 hours ; about 300 in the first month; and for succeeding months, pee 4 8 Ie i 13, 15, 21 23 2. . Lhe: record. is recognized as fragmentary, and the actual number of sensible shocks was probably much larger. There was somewhat volu- minous testimony to the occurrence of visible undulations of the surface of the ground, the speed of which was much slower than that of the elastic waves in rock. Cracks opened in many places near the fault; from several of these were large temporary discharges of water or of water and sand; the circulation of underground water was seriously and per- manently deranged, springs being destroyed, created or changed in volume; landslides and earthflows were precipitated in great number. Alluvial lands slumped toward stream channels, and soft ground was in some localities left with a wavy surface. 52 Gilbert—The California Earthquake. The volume closes without discussing the subject of future earthquakes in the San Francisco region, but furnishes material pertinent to that discussion by publishing accounts of the earth- quakes of 1868, 1865 and 1857. The fault in 1857 was on the southern part of the San Andreas rift, and the fault in 1865 may have been on the same rift near the southern end of the fault of 1906. The fault in 1868 was on a parallel rift east of the southern arm of San Francisco bay. In each ease the distri- bution of intensity in San Francisco was substantially the same as in 1906, the character of the ground having more influence than the direction of the origin. The second and closing volume of the report will be by H. I’. Reid, and will treat of the theory of the seismogram. T. D. A. Cockerell—Descriptions of Tertiary Insects. 538 Arr. III.—Deseriptions of Tertiary Insects; by T. D. A. CocKERELL. Part V. Some New DIptTeRA. Lasiosoma mirandula sp. nov. (Mycetophilide : Sciophiline). Expanse 16™; length of body about 10™, of wing 7™™; abdomen reddish, with the hind margins of the segments rather broadly blackened, its whole surface with minute appressed hairs; legs pale brown, the femora minutely hairy; wings wonderfully preserved, strongly rufescent, with a purple or pink tinge, nervures darkened. By the dusky wings and the short prostrate hairs on abdomen it agrees with the living LZ. pallipes (Say), but it is considerably larger than Say’s species. The venational features are as follows: the costal thickening extends a short distance beyond the tip of the ultimate branch of the radius (third vein); swbcosta, much as in the fossil Sciophila hyattc Secudd., does not distinctly reach the costa, but is evanescent after the little vein which passes from it to the radius, meeting the beginning of the inferior branch of the latter ; small vein from costa to subcosta distinet, oblique, forming an angle of 45° with each, and placed a moderate dis- tance (about 2mm) from base of wing ; branches of radius as in Sciophila, with the same little cell formed in the fork by R,,; running up to join R,: media, as usual, weaker than radius, and forking almost immediately after leaving the radio- medial cross-vein, so that the stem before the fork is shorter than the cross-vein, although the latter is short and not very far from vertical; cubitus forking not far from base as in Sciara ; anal with its apical portion wanting, as in Ceroplatus. In Williston’s tables (N. A. Diptera, 3d ed.) this runs exactly to Lasiosoma, and seems to accord well with that genus.* The living American species are northern. flab.—Florissant, Colorado, in the Miocene shales, Sta. 14 GS. A. fohwer, 1907). Holotype in Peabody Museum (Yale). Tetragoneura peritula sp. nov. (Mycetophilide : Sciophiline). Length 4°"; wing 33, antenna 12™™; dorsum of head, tho- rax and abdomen dark brown, the rest of the body pallid ; legs long and slender; wings hyaline, with brown nervures. *Tt differs, however, iat Handlirsch’s figure (Foss. Ins., pl. vi) of Lasio- soma in the shorter subcosta, not ending on costa, and also in the more ver- tical radio-medial cross-vein. Handlirsch’s figure does not show any cell in the forks of the radius, so it may not be of this genus. 54. 7. D. A. Cockerell—Descriptions of Tertiary Insects. Antennee with about 16 joints, the middle joints much broader than long (about 102 mw broad, and 76 long); scutellar region with two very long stout bristles, 459 w long, the other bristles of thorax much shorter ; thorax very strongly convex above ; legs and abdomen with extremely fine hairs; hind tibize with a row of short black bristles, about 93 uw long. Venation: sub- costa reaching to about the middle of the wing, that is to say, not abbreviated, and ending in a very broad V, the upper branch extending to the costa, and the lower to “the radius ; radius normal, its lower branch leaving it a short distance before the termination of the subcosta, and emitting, shortly after that termination, the oblique cross-vein to R, which really represents R»,3; Rus normal, ending very near apex of wing; oblique radio-medial crossnervure very long, about three times as long as the nearly vertical first section of lower’ branch of radius; media with a long fork; cubitus not dis- tinctly preserved (it ought to be forked). Hab.—A few miles north of Rifle, Colorado, in rocks of Kocene age, probably of the Green River Group, but possibly Wasatch. Type in collection of Dr. 8. M. Bradbury. This cannot be identified with any of Scudder’s fossil Mycetophi- lide. Professor O. A. Johannsen very kindly examined my sketch and notes, and suggested the generic reference. He writes as follows : “The subcosta in most of the species thus far described is short, and ends either free, or in R; in one species described by Walker it ends in the costa; in one species of Meunier it is long, though ending in R. As only about sixteen species (including fossils) are known of this genus, and these quite rare, its limitations are difficult to define. I should be inclined to call your fossil Zetraguneura, though acknowledging it as somewhat aberrant” (litt. Aug. 19, 1908). The known fossil species of Tetragoneura number seven, all from Baltic amber, described by Meunier. As the amber is of Oligocene age, the species now described is the oldest known. Alepidophora g. nov. (Bombylide). A genus with elongate, subcylindrical abdomen, looking not unlike a bee. In Williston’s tables (N. Am. Dipt., 3d ed. , p. 216) it runs to 29, and has very much the build of Lepidophora lepidocera (appendiculata), except that it is not at all scaly, the wings are very much shorter, and so far as can be seen, the mouth- -parts are not elongated. The anterior tibize (the only ones visible) are not bristly, as they are in Sphenoidoptera. In the hairy abdomen it differs from Paracosmus; but the course of the second vein is as in Paracosmus, not as in Metacosmus. T. D. A. Cockerell—Descriptions of Tertiary Insects. 55 By the characters of the abdomen and venation it 1s excluded from Aphoebantus and the related Epacmus and Hucessia. The characters of the venation are as follows: (1.) Second vein (Re4s)) arising at the same point as the third, and about 390 mw basad of discal cell. Near its end it curves upwards, and ends on costa at an angle even more obtuse than that presented by Pantarbes (Williston, l. ¢., p. 212). — (2.) Third vein Ry, robust, gently curved, with its lower branch (R,) forming a gently curved but nowhere angled line; upper branch (R,) leaving it at right angles, and after 255 fb bent at a right angle, but emitting a short vein (rudiment of the cross-vein) in a str aight line with the second section, so that the whole branch represents a T resting on the third vein, and having one of its sides prolonged and bent upwards to reach the costa. The end of the branch is not bent nearly so much as the end of the second vein, and its inner angle with the costa is not very much greater than a right angle. In general, all this is much as in Pantarbes, except as to the rudimentary cross-vein directed basad (in Pantarbes the cross-vein is com- plete and directed upwards). (3.) Radio-medial cross-vein much beyond middle of discal cell (about 760 w from its apex), and 255 mw long. (4.) First posterior cell open at apex, the opening about 120 mw wide. (5.) Discal cell long and rather narrow (its length about 23™™) shaped as in Systrophus (the bounding nervure having the same curves), except that 1t is much longer. (6.) Second posterior cell narrow (806 mw) at base, and extremely broad at apex (i.e. on margin); third posterior broad at base, and narrowed apically; fourth (morphologically fifth) very broadly open, formed as in Pantarbes, but longer ; its base is 476 w from base of discal cell. (7.) Anal cell rather widely open. Alepidophora pealei sp. nov. Length 12"; of wing 63; of abdomen about 8; width of abdomen 32™™"; head and thorax black ; abdomen dark reddish- brown; wings hyaline, nervures brown, costal region (between costa and radius) reddened; as preserved, the abdominal seg- ments appear as widely separated dark chitinous bands, with broad colorless intervals between, these intervals being about half the size of the chitinous rings. Eyes with facets of two sizes, the smaller about 22 mw diameter, the larger about 42 yp; the two kinds seem to be about equally represented, the division apparently longitudinal, and not abrupt. Tarsi with scattered strong bristles. Third abdominal segment slightly bristly or hairy, fourth with a conspicuous patch of dark hairs on éach side, fifth and sixth moderately hairy, the hairs dark. 56 7. D. A. Cockerell— Descriptions of Tertiary Insects. Hab.—Florissant in the Miocene shales, 1908. On the same slab, close to the fly, are the leaves of Hagus longifolia. While I was preparing the above description, Dr. A. C. Peale, the discoverer of the Florissant shales, visited my laboratory. It is with much pleasure that I dedicate the species to him. Holotype in Peabody Museum (Yale). Pachysystropus gen. nov. (Bombyliide). Rather large, cylindrical-bodied, with a strong projecting proboscis; antennge with a sharp apex, constructed essentially as in Geron ; hind femora stout and hairy. In Williston’s table (N. Am. Diptera, 3d ed.) it runs straight to Dolichomyia (the eyes are not very distinct, but I feel sure not holoptic), Gel Pachysystropus rohweri Ckll. but the venation agrees better with that of Systropus, differ- ing, however, as follows: (1.) The lower half of the cross-vein from the bend of R, to R,43 1s present, and very distinct, though the upper half is wanting. ‘This vein is absent in iy ystropus (though the abrupt bend remains to indicate where it was), but is complete in Pantarbes and Hxoprosopa. : (2.) The first posterior cell is closed just before the margin of the wing, a condition approximately intermediate between that of Systropus (in which it is open) and Pantarbes. (3.) The anal cell is closed just before the margin, as in Ocondocera (N. Am. Dipt., f. 82). The venation is very well T. D. A. Cockerell— Descriptions of Tertiary Insects. 57 preserved, and the existence of only three posterior cells is certain. The anal cell in the 8. African Systropus crudelis (as figured by Sharp) is like that of Soa irop 6. Pachysystropus rohweri sp. nov. Fig. 1. Black or dark brown, the wings hyaline, with dark nervures; apical half of area between radius and costa fuliginous ; length (excluding proboscis) 153™"; proboscis rather stout, a little over 3™™ long ; antennee 22™™, the last joint very sharp- pointed, 663 w long; width of thorax 4™™; of the parallel-sided abdomen about 21™™, its apex not swollen; lateral anterior corners of first three abdominal segments (especially the sec- ond) projecting at an acute angle; fourth and fifth segments with dark hair at sides; hind femora about 4™™ long, stout, the posterior side with much long dark hair; length of wing 82™™; base to anterior cross-vein 52™™, Hab Florissant, in the Miocene shales, Sta. 9. (S. A. Rohwer, 1906.) Holotype in Peabody Museum (Yale). Callimyia (?) hypolitha sp. nov. (Platypezide). A small stout-bodied fly with long wings; as preserved, the head and thorax are dull black; the abdomen conspicuously shining, dark reddish-brown, with the hind margins of the segments black; wings hyaline, nervures pale. Length of body 43™™, of wing 453; length and width of abdomen each about Qin, but the apex is not visible (appar- ently turned downwards) ; ‘thorax robust; head broad, but not quite so wide as thorax. Venation, as preserved (the subcosta, radius and branches, and anterior cross-vein are visible), exactly as in Callimyia eWalici N= Ams Dipt., 3d ed., p. 242, £. 2) except. that | cannot demonstrate any spinulosity on the radius, but the veins are so nearly the color of the rock that this might well be invisible. The first posterior cell is widely open, as in Cadli- myia. The subcosta ends on the costa at about the middle. flab.-—Near Rifle, Colorado, in Eocene rocks; the locality and other particulars being the same as already given for Tetragoneura peritula. Only two Tertiary Platyperidze have been previously de- scribed ; Oppenheimella baltica Meunier, from amber; and Callimyia torporata Seadder, from the Green River beds of Wyoming. C. hypolitha is a much larger species than C. torporata. Since writing the above I have found the reverse impression of C. hypolitha, showing the anterior branch of the media 58 TL. D. A. Cockerell—Deseriptions of Tertiary Insects. very distinetly. The media turns downwards near its distal end, and the first posterior cell is more widely open than in Callimyia. This downward bend is to the apical corner of the discal cell, which forms a somewhat acute though large angle, and from that point onwards the media is directed straight to the margin. (The margin and immediate vicinity at this place are not visible.) This arrangement of the media, ete. resembles that of Ocydromia (Empidide). Scudder’s C. torporata also has the very widely open first posterior cell. Leptis florissantina sp. nov. (Leptide). A small, slender species, beautifully preserved, with expanded wings. Length 8"; wing 7; expanse 15"™; width of head 2™", of the abdomen 14. Antennze not well preserved, but - the third joint seems to be large, much as in H/elarimorpha ; I cannot see the styles. Eyes very widely separated above ; head broader than long; thorax small ; head and thorax black ; wings hyaline, without spots, veins dark reddish-brown; abdo- men parallel-sided, a little broadened to the obtuse apex, the basal two segments pallid, the others largely dark (perhaps originally wholly dark). Venation as in Leptis ; compared with ZL. mystacea Macq. (Williston, N. A. Dipt., 3d ed., p. 157) the following shght differences are found : (1.) Costa not or barely arched near base. (2.) Wings narrower. : (3.) The second vein ends nearer apex of wing, beyond level of middle of cell in forks of third. (4.) Bases of second and third posterior cells about half a millimeter back of level of base of cell in forks of third vein. (5.) Anterior cross-vein (radio-medial cross-vein) nearer to middle of discal cell. The anal cell is barely closed, just on the margin of the wing; there may be an infinitesimally small opening. /Tab.—Florissant, in the Miocene shales, Station 13 B (WS. A. Lohwer, 1908). Four species of Lepizs have been described from amber. Tipula heertana nn. Tipula lineata Heer. Ins. Oen. II, p. 194, t. 15, 24 (1849).—Miocene of Radoboj (not 7. lineata Scopoli, Ent. Carn., p. 320). Tipula lineata Heer, Scudder, Proc. Am. Phil. Soc., 1894, jOn 2 Limnophila meunieri n.u. Limnophila gracilis (Lw., as Tanysphyra, Scudder, Proce. Am. Phil. Soc., 1894, p. 21 (mom. nud.); Meunier, Ac. Se. Nat. (9) iv, p. 382, t. 14, f. 9 (1906).—Baltic amber (not L. gracilis Wiedemann, Auss. Zw. 1, p. 28). Gooch and Beyer—Electrolytic Estimation of Lead. 59 Arr. IV.—The Electrolytic Estumation of Lead and of Manganese by the Use of the Filtering Crucible; by F. A. Goocn and F. B. Bryer. [Contributions from the Kent Chemical Laboratory of Yale Univ.—exciii. | Ly a former paper* we have shown that the filtering crucible may be put to advantageous use in an electrolytic cell for the treatment of deposits not compact and adherent enough to be handled rapidly and conveniently by ordinary methods of electro-deposition. Four devices were described: I, a closed ceil in which the perforated platinum crucible is adapted to use as an electrode and to filtrations after interruption of the electric current; II, a closed cell in which the perforated platinum crucible is used as an electrode and in subsequent filtrations without imterruption of the current; III, a cell in which the perforated platinum crucible is adjusted to a filter- ing flask for continuous filtration during electrolysis; IV, a cell in which a perforated porcelain crucible with included electrode of platinum is arranged, like the platinum crucible of Iil, for continuous filtration during electrolysis. It was shown that by either of the devices described reasonably rapid and accurate electrolytic determinations of copper may be made without the use of rotating motors or expensive apparatus of platinum. Im testing these devices, copper sulphate was electrolyzed, with an error ranging between +0°v003 grm. and —0:00038 grm. upon approximately 0°1274 germ. of copper or 0°5000 grm. of the sulphate. The duration of the elec- trolysis was about thirty minutes in the processes involving continuous filtration and forty-five minutes in the processes in which filtration was begun after electrolysis was completed. The metallic copper deposited upon the cathode was partly compact, partly spongy. In the work to be described the apparatus has been tried in the more difficult determinations of manganese and lead as the dioxides formed upon the anode in very imperfectly adherent condition. The Determination of Lead as the Dioxide. In depositing lead dioxidet electrolytically, solutions contain- ing nitric acid are employed; precautions must be taken in regard to concentration of acid, strength of current and tem- perature ; and the liquid is siphoned off before interruption of the current. With the rotating cathode making 600 revolu- tions a minute and a sand-blasted platinum dish for the anode, Exner obtained in ten to fifteen minutes adherent * This Journal, xxv, 249, 1908. +Smith, Electro-analysis, p. 101, edition of 1907. 60 Gooch and Beyer Electrolytic Estimation of Lead. deposits with a current N.D.,,.=10 amp. and 4°5 volts, acting upon 125° of solution contaming 20° of concentrated nitric acid. In some of our preliminary trials of electrolysis in the closed cell with subsequent filtration it was found that when the con- centration of nitric acid amounted to 10° in 60°™ of liquid, with a current of 4 amperes (N.D.,,,=10 amp.) and 6 volts, two sources of error appeared. In the first place, the depo- sition of metallic lead upon the cathode was often noticeable ; and secondly, it appeared to be impossible to make the precip1- tation of lead dioxide complete so long as that substance was allowed to float in the liquid. Similar results were obtained in experiments in which urea was added to the liquid for the purpose of obviating the sol-~ vent action of dissolved oxides of nitrogen upon lead dioxide. In the experiments with this form of apparatus the stirring of the asbestos felt by gas evolved upon the bottom of the erucible used as an anode, as well as the deposition of oxide on the outer surface of the crucible, was prevented by tak- ing the precaution to moisten the asbestos, from the outside, with a drop of nitrobenzene which, being insoluble in water, prevents the contact of the aqueous electrolyte with the electrode surface under- neath the asbestos. An increase of nitric acid to the proportion of 30°™" in 100°" (or solimtien served to prevent the deposi- tion of lead upon the cathode, but to prevent the re-solution of lead dioxide it was found to be necessary to use the process of continuous filtration, so that the deposit might be compacted upon the felt, and after deposition was complete to replace the acid liquid by a solution of ammonium nitrate without interruption of the current. After washing out the nitric acid with the solution of ammonium nitrate the tinal washing was completed with water. The form ot apparatus employed, shown in figure 1, and the manner of using, were fully described in the former article to which reference has been made.* In Table I are * This Journal, xxv, 249, 1908. 1NEs, 5 Ie Gooch and Beyer—L lectrolytic Estimation of Lead. 61 given the results of experiments following this procedure, and, for comparison, the result of an experiment, (1) in which it was found that, though electrolysis was continued by the cir- culating process until the filtrate contained no lead, traces of lead dioxide went into solution after the amount of electricity which passed had been diminished by the gradual dilution with water used in washing to replace the electrolyte. Tests for lead in filtrates and washings were made by neutralizing with ammonium hydroxide and adding ammonium sulphide, or acetic acid and potassium chromate. TABLE I. Electrolysis with Continuous Filtration. HNO; Current Pb(NOs)2 Vol. cone, ———-+- — Time PbO. Theory’ Error Amp. NDjoo Volt found for PbO, cem®*, Mifiss | SUM: erm. erm. A With no ammonium nitrate in electrolyte or in wash-water. (1) 0°2028 50 15 2 5 4 5 4 10 5 1380 0°1460 0:1436 —0°0024 B With ammonium nitrate in electrolyte and in wash-water. (2) 0°2022 50 15 2 3) “ 40 4 10 5 100 0:1459 0°1462 +090:°0003 (3) 0°2014 50 15 2 5 4 9) 4 10 5 115 0°1454 0°1458 +0:0004 (4) 02001 50 15 2 a) + 5 ASO 5 115 0°1444 0°1442 —0:0002 (5) 0°2006 50 15 2 5) a 5) 4 10 5 115 0°1448 0°1446 —0:0002 (6) 0:2046 50 15 2 5) 4 9) 4 10 5 115 0°1477 0°1472 —0:0003 With ammonium nitrate in wash-water only. (8) 0°2020 50 15 2 5 + 5) 4 10 5 115 0°1458 0°1460 +0:0003 (9) 0°2037 50 15 2 9) + 3) 4 4 10 5 115 0°1470 0°14738 +0:00038 From the results of the experiments described, it appears that good analytical results may be obtained with the filtering crucible used as an electrolytic cell if nitric acid be present to the proportion of 30° of the concentrated acid in 100°™ of solution, the liquid kept in continuous filtration until the elec- trolysis of the lead salt is complete, the acidic liquid replaced by a solution of ammonium nitrate so that the electric current passing shall not fall off until the nitric acid has been removed, 62 Gooch and Beyer—KElectrolytic Lstumation of Lead. the final washings made with water, and the deposit weighed after drying at 200°. The time required for the complete deposition of 0°15 grm. of lead dioxide under the conditions described is about two hours. The Determination of Manganese. For the electro-deposition of manganese as the dioxide various processes have been described.* With stationary electrodes solutions containing nitric acid, sulphuric acid, Fie. 2. acetic acid, formic acid with or without a formate, or ammo- nium acetate alone, with chrome alum, or acetone, have been employed. For use with the rotating anode, solutions contain- ing ammonium acetate with chrome alum or alcohol have been adyocated.+ In all these processes hydrated manganese dioxide is deposited upon a large anode which is preferably a roughened platinum dish of considerable capacity. The experiments to be described have been made to test the utility of the electrolytic filtering cell in the determination of manganese as the dioxide. The procedure adopted was the * Smith’s Electro-analysis, edition of 1907, p. 134 et seq. + Koester, Zeitsclhr. Electro-chem., x, 553, 1904. Gooch and Beyer—Electrolytic Estimation of Lead. 63 simplest. Fifty-centimeter portions of a solution of pure manganese sulphate, standardized by evaporation of measured portions and gentle ignition of the residue over a radiator,* were treated, in each case, with six drops (0°17) of concen- trated sulphuric acid and electrolyzed in the filtering cell with a current of 2 amperes (ND.,,,.=5 amp.) and 20-10 volts, the voltage decreasing as the solution became heated. In one set of experiments the process of continuous filtration during electrolysis, for which the adjustment of apparatus is shown in figure 1, was employed: in a second set of experi- ments the closed cell, shown in figure 2, was used during the electrolysis and the adjustment for filtr ainem made subsequently as previously described.+ The time required for the deposition of 0°1860 germ. of the dioxide was one hour and three-quarters in the former process: a period varying from two hours and ten minutes to two hours and fifty minutes is required in the latter process. Tests with hydrogen dioxide and ammonia showed that the deposition was complete in the process of continuous filtration and practically so in the closed-cell pro- cess. The closed-cell process naturally requires less attention during the electrolysis, and so it is advantageous to run the process for a period, perhaps two hours, with the closed cell and then to adjust the apparatus for filtration during further electrolytic action in order that floating particles of the dioxide may be drawn to the felt and completeness of precipitation may be assured. In this way the advantage of the circulating process may be obtained with less attention to manipulation than is required when the filtration is continuous from the start. The deposit was washed with water after interruption of the current, first dried at 200° for ten or fifteen minutes and weighed, and thereafter ignited to low redness in the spreading flame of a large burner.t Results of experiments with the cell arranged for continuous filtration, and of experi- ments in which the closed cell was used until the electrolysis was nearly over, are given in the accompaning table. The results are evidently as good as could be expected of any process which involves the weighing of manganese dioxide brought to condition by heating. The degree of oxidation of the oxide thrown down under the conditions which obtain apparently approximates closely to that of the ideal oxide represented by the symbol MnO,.H,O, formerly assigned by Riidorff$ to the electrolytically formed oxide, and differing in that respect from the electrolytically deposited oxide which was studied by Groeger.| * This Journal, v, 209, 1898. + This Journal, xxv, 249, 1908. t This Journal, v, 214, 1898. S$ Zeitschr. angew. Chem., 1892, 6. | Zeitschr. angew. Chem., 1895, 253. (eye 50) al 64 Gooch and Beyer—Klectrolytic Kstumation of Lead. TABLE IT. Solution H.SO, Theory MnO, MnO, of MnSO, cone. Current for weighed weighed Error taken = MnO. as MnO, as Mn;0, em® em? ‘Amp. ND.100 Volt erm. erm. erm. A Electrolysis with continuous filtration. (1) 50 Olen 2 3) 20 — 12 01860 0:'1862 + 0:°0002 0°1858 —0°0002 ) 50 0°17 2 3) 20 — 12 0°1860 0°1856 —0°0004 0°i856 —0°0004 5 PAY —— A PMID Op lleiess —0°0017 0°1872 +0°0012 bo B Klectrolysis in closed cell with subsequent filtration. > (4) 50 Oy 2 5) 20° — 12 O18607 O21860 0:0000 0°1853 —0-0007 (5) 50 On Tae 2 9) 20 — 10 O°-1860 0°1856 — 0°0004 0°1856 —0°0003 (6) 50 0-17 2 5) 18 — 10 01860 0°1853 -— (0007 0°1858 0°0002 Somewhat greater regularity in results might be expected if the manganese dioxide could be converted to manganous sul- phate and weighed as such, but experiments made with this end in view were unsuccessful. The application of gaseous sulphur dioxide proved to be ineffective and sulphuric acid attacked the asbestos felt during ignition, causing a permanent increment of weight. The substitution of spongy platinum for asbestos in the filtering crucible, as suggested and used by Monroe,* served to obviate the difficulty due to the action of the sulphuric acid upon the filtering medium, but the process of removing the necessary excess of sulphuric acid by gentle heating over radiator was exceedingly slow and, if pushed, liable to errors of mechanical loss. To weigh as either form of oxide, in this process, is therefore better than to attempt the conversion to manganese sulphate. The processes demonstrated for the electrolytic deposition of lead dioxide and manganese dioxide with the use of the filtering crucible are obviously inferior in point of convenience to the more rapid processes which demand the use of large and special platinum containers and rotating motors, but in absence of such apparatus they may serve a useful purpose. * Chem. News, lviii, 101. Ashman—Radio-Actwwity of Thorium. 65 Art. V.—The Specific Radio-Activity of Thorium and its Products; by G. C. AsHMAN. THE radio-activity of thorium compounds and minerals was discovered by Schmidt* and independently by Mme. Curiet ; Struttt also found that all thorium minerals examined by him showed radio-active properties. Debierne§ discovered actinium while working up uranium ores containing thorium. The similarity of the chemical properties of actinium and thorium led to the suggestion by a number of chemists that the activity of thorium is not due to thorium itself but to slight traces of actinium, since actinium is very difficult to separate from tho- rium and the other rare earths. This view is hardly tenable in the light of the fact that thorium and actinium give emana- tions with totally distinct properties: their rates of decay are widely different, and their products are in no way identical. In 1902 Hofmann and Zerban| announced that they had obtained an inactive thorium preparation from a Brazilian monazite sand, and that thoria prepared from various minerals, although active at first, became inactive after a few months. Basker- ville and Zerban4| also claimed they had separated from a South American mineral thoria which was perfectly inactive. A little later Hahn** and Ramsaytf extracted from the min- eral thorianite a radio-active preparation several thousand times more active than thorium itself and yielding a propor- tionately larger amount of thorium emanation. This discovery made it appear possible that the activity of thorium might be due wholly to radiothorium since the latter possesses an extreme tendency to retain its association with thatelement. Papers bear- ing on this question were published simultaneously by Bolt- wood ,ttby Dadourian,$§ and by McCoy and Ross||._ The con- cordant results of these three independent investigations proved conclusively that the intensity of the radio-activity associated with thorium in any mineral is directly proportional to the tho- rium content of the mineral. This work, together with the preparation of radiothorium from thorium minerals by Hahn and * Ann. d. Phys., Ixv, 141, 1898. £C. i, cxxvu, 1101, 1898:: { Proc. Roy. Soe., London, Ixxvi, 88 and 312, 1905. SCOR. xxix, 593, 1899 5 exxex: 206, 1900. i Ber. d. Chem. Ges., XXXV, 531, 1902. “| J. Amer. Chem. Soe. ils 1642. 1904, ** Ber. d. Chem. Ges., xxxvili, 3371, 1905. t+ J. de chim. phys., iii, 617, 1906. t{ This Journal, xxi, 409, 1906. S§ Ibid., xxi, 497, 1906. ||| Ibid, xxi, 433, 1906. Am. Jour. Sco1.—FourtH SERIES, VoL. X XVII, No. 157.—January, 1909. 5 66 Ashman—Ladio-Activity of Thoriwm. Ramsay, and the demonstration that the extracted radiothorium produced thorium-X and the subsequent products left no doubt that radiothorium was produced by the disintegration of thorium, but the question still remained whether this disintegra- tion of thorium itself was accompanied by a-rays; that is, whether thorium 7¢self was radio-active. McCoy and Ross found that all of the activity of a thorium mineral, not due to uranium, remained in the pure thorium dioxide, separated by. Neish’s method : the measurements were made at the end of a month to allow the accumulation of the maximum amounts of thorium-X and subsequent products. Pure thorium dioxide made from commercial samples of thorium nitrate had about half the normal activity. This was at first thought to be due to the removal of part of the radiothorium in the technical process of purification. McCoy and Ross attempted to separate. radiothorium completely from thorium, but found it apparently impossible to do so. Hahn found that the activity of com- mercial samples varied with the age of the material; the activity was smallest for samples three to nine years old. A sample twelve years old had greater activity. To explain these results, Hahn* suggested that there is a rayless intermediate product, mesothorium, having a period of about seven years, between thorium and radiothorium ; that this is separated in the process of extraction of thorium from minerals, and that the radiothorium, which has a period of two years, decays with time, causing the observed fall of activity of commercial samples. Some observations by Boltwoodt tended to confirm this view. Later quantitative experiments by McCoy and Ross showed that the hypothesis was in good agreement with the facts and that the period of mesothorium was five and one-half years; this value has since been confirmed by Hahnt by new quan- titative measurements. Hahn also compared the activities of old and new thorium by means of the a-rays, the @-rays, and the emanation ; the variation with age in activity of the emana- tion is greater than the variation in the a-ray activity. The removal of thorium-X caused a greater proportional decrease in the activity of new than in old thoria. The activity of radiothorium, when freed from thorium-X, was decreased to a smaller fraction of its original value than that of any ordinary thorium preparation similarly treated. These facts led Hahn to conclude that thorium itself has a typical a-ray aca but he gave no estimate of its intensity. Rutherford and Soddy§ had observed that in the case of thorium precipitated with ammonia, its final or maximum * Phys. Zeitschr., viii, 277, 1907. + This Journal, xxiv, 93, 1907. +t Phys. Zeitschr., ix, 246, 1908. § Phil. Mag., iv, 378, 1902. Ashman—Radio-Actwity of Thorium. 67 activity after one month was about four times the initial activ- ity. McCoy and Ross* found the ratio of final to initial activ- ity to be approximately 2°5 for various samples of thoria prepared from a commercial nitrate. The corresponding ratio for thoria prepared from minerals was about 3:2. The authors at that time considered this to prove conclusively that thorium is itself active, and estimated that the specific activity of thorium dioxide was between 100 and 130. The work here described was undertaken at the suggestion of Professor McCoy with the object of determining the a-ray activity of thorium itself with accuracy. A brief preliminary mention of my results was made in the paper of McOoy and Ross. The activity of thorium itself is found from the experi- mental data as follows: The activity of new thorium freed from the easily separated products thorium-X emanation, thorium A, thorium B, and thorium ©, is due to Th + Rt. But in the course of a month the products ( Pr) accumulate in equilibrium amounts, and the activity is then due to Th + Rt + Pr. The activity of old thorium freed from the products is due to Th + #Rt, where z is the fraction of the equili- brium amount of radiothorium in the sample; and after an interval of one month the activity is due to Th = (RE Pr). These four relations lead to four equations by means of which the four unknown quantities, activity of Th, Rt and Pr, and the fraction « may be found. McCoy and Ross explained that the uncertainty of the data upon which their estimate was based was due to the fact that by the large number of precipitations with ammonia, which were necessary to remove the separable products, Th-X, etc., large quantities of silica aud other impurities from the glass and reagents were intro- duced into the thorium. A further disadvantage of the am- monia method arises from the fact that Th-A, with the com- paratively long period of 11 hours, is precipitated with the thorium. This makes it necessary to carry out 12 to 15 pre- cipitations in the course of three or four days in order com- pletely to remove the separable products. Schlundt and Mooret found that in the precipitation of thorium by fumaric acid, according to Metzger’s method for the analytical separation of thorium from other rare earths, Th-A as well as Th-X remains in the solution to a very large extent, while Th-B is carried down with the thorium. This method would therefore seem to offer an easier way to separ- ate the active products of thorium than the precipitation with ammonia; but it had the disadvantage of requiring an expen- * J. Am. Chem. Soc., xxix, 1709, 1907. tJ. Phys. Chem., ix, 682, 1905. 68 Ashman—Radio-Activity of Thorium. sive reagent and the necessity of working in alcoholic solutions. Schlundt and Moore* also found that precipitation with nitro- benzoic acid removed some form of radio-active matter from thorium but they did not identify the products separated. The extensive use of meta-nitrobenzoic acid by McCoy and Ross} in the analysis and purification of thorium minerals sug- gested also the use of this reagent as a substitute for fumarie acid. It was found that the first precipitate of thorium with meta-nitrobenzoic acid lost its activity at a much greater rate than would correspond to the period of thorium-A. The minimum activity was reached in four or five hours, then an increase due to the growth of thorium-X and its products set in. When the precipitate was dissolved and the thorium reprecipitated at the end of two hours the activity was dimin- ished still further; and it was found that two additional pre- cipitations at intervals of two hours gave finally pure thorium dioxide free from thorium-X and all its subsequent products. The activity of the oxide prepared by this method began immediately to increase. On account of the convenience of working in aqueous solutions and the ease and rapidity with which filtration takes place, the nitrobenzoic acid method offers many advantages over the fumaric acid method, and leaves nothing to be desired concerning purity of the product and completeness of separation. The precipitation with nitro- benzoic acid was carried out in the following manner: The solution of thorium nitrate, containing approximately 2 grams of thoria, was nearly neutralized with dilute ammonia, methyl orange being used as indicator, a slight excess of a saturated solution of nitrobenzoic acid was slowly added, and the mix- ture kept at a temperature of 80° for a short time. The pre- cipitate of thorium nitrobenzoate was filtered from the solution and washed well with water. Two hours later it was dissolved in dilute nitric acid, ciluted to about 300°, almost neutralized with ammonia and the thorium then reprecipitated by the addition of 400° more of the nitrobenzoic acid solution. The fourth thorium precipitate was rapidly filtered from the solu- tion, placed directly in a platinum crucible and ignited first over a Bunsen flame and finally at the highest attainable tem- perature of the blast lamp for ten minutes. Four lots of thorium oxide were thus prepared ; two from “old” material, two from thorite. Oxide “A” was: from sample “A” of thorium nitrate described by McCoy and Ross.{ It had been precipitated 100 times with ammonia and was known to be poor in radiothorium. It was repurified by the nitrobenzoie * loc. .cit. +J. Am. Chem. Soc., xxix, 1709, 1907. tJ. Am. Chem. Soc., Ob. 1719, 1907. Ashman—Radio-Activity of Thorium. 69 acid method and converted into the oxide by ignition. Oxide “B” was from sample “B” of thorium nitrate described by McCoy and Ross. It had been precipitated 40 times with hydrogen peroxide and contained about one third of the equilibrium amount of radiothorium. It was twice purified by Neish’s method, and finally by four precipitations with nitrobenzoic acid, made at intervals of two hours, Samples “C” and “ D” were oxides made from thorite from Arendal, Norway. Nine grams of the finely powdered mineral were digested for a number of hours with concentrated hydro- chloric acid. The chlorides were dissolved in hot water and filtered from the insoluble residue. The thorium was then precipitated with a boiling solution of oxalic acid and washed free from the excess of the acid. The precipitated oxalates -were decomposed by boiling them for ten minutes with fifteen grams of potassium hydroxide in 30° of water. The thorium hydroxide was washed free from alkali and dissolved in dilute nitric acid. From this solution the thorium oxide was obtained free from thorium-X and all subsequent products by four precipitations with nitrobenzoic acid in the manner described. The thoria thus prepared was made into films, 7 in diameter, as quickly as possible by Boltwood’s method,* paint- ing the paste onto a metal disc with a camel’s-hair brush. Owing to the rapidity with which the activity of the thoria increased, the slower sedimentation process,+ which yields more uniform films, could not be used. _ However, the error due tolack of uniformity was doubtless negligible since one set of films, “ D,,’’ made by the sedimentation process gave the same maximum specific activity, 948, as did the painted films from the same material; see Table l. Activity measurements were made in the manner described by McCoy and Ross,t and with the same electroscope.§ From five to eight films were made from each sample; the films were made thin, 0°2 to 7 mg. per square cm., in order to avoid errors due to the evolved emanation in the case of material containing the equilibrium amount of Th-X.| In order to find the activity of the thorium oxide at the time zero, i. e., at the moment when thorium-X and its prod- ucts were completely removed from it, the activity of each film was measured at intervals of a few hours during the first day after its preparation. The increase of activity with time was plotted and the activity at time zero found by extending the curve back to the ordinate for zero time as illustrated in * This Journal, xxv, 269, 1908. + McCoy, J. Amer. Chem. Soc., xxvi, 391, 1905. ¢ Loe. cit. § This Journal, xxvi, 521, 1908. || McCoy and Ross; this Journal, xxi, 483, 1906. Activity. .80 -60 70 Ashman—Radio- Activity of Thorium. the accompanying curve, which represents a film of sample “DD.” The activities are in terms of the U,O, standard, which had an activity of 35:0 units. This correction was necessary as the time intervening between the last precipitation of the thorium and the first activity measurement was usually one to two hours. LEW eE, 8 1b. a}9) 2 4 6 8 10 12 14 16 18 20 22 24 Time in Hours. Table I gives the results obtained from the four samples of oxide. TABLE I, Date of Measurement Date of Minimum of Maximum Sample preparation* activity maximum activity activity Pee alae 3 bo Y 10 40 8 ost geet f 4 nx10°° 30 6 0 Ss, | aa 773 20 4 a es aden ee ae ee 10 2 jod= dfs | Jano" ! dai ee xh Jl, a> CN NIN 170) Pe MAI IB AB. SRO Inferences. 5. Interference and diffraction.—The tables and chart show in the first place, that the disc and first ring of the coronas are alternately of a vivid green, other colors being dull because the remaining lines of the mercury spectrum are faint. At inter- 80 OC. Barus—Coronas with Mercury Light. vals neither disc nor ring are quite green. Hence there is a periodic term impressed on the diffractions, which may be iden- tified as an interference similar to the case of the lameiiar grating referred to in another paper.* When monochromatic light is used it is necessary, therefore, to observe both the edge of the disc and the inner edge of the first ring; for neither appear vividly at the same time. The chord s on a radius of 30°" for the minimum in terms of the corresponding chords s’ and s’”’, of the first and second edges specified, may then be written. s= ‘55 + 1:06:87, 9 5 — 50) ob DA g Probably the ratio-s/s’ and s/s’” should be constant and the absolute term in these equations is an error of observation; but _ as it is small, little depends upon it, millimeters only being significant. If we summarize all the observations for ds/dt, the agree- ment as a whole is in keeping with the nature of the observa- tions and reasonably satisfactory. Thus, in Series I, II, d’s/dz = -90, | s='44 + °85 s' (goniometer in front), III, Iie, IV, ese | Vs 110, | s=54+4+1-:06 s’ (goniometer behind), VI, 1-13, r mean ds’ / dz = 1°12. Vie ise | VIII, LOZ, | The feature of these data is the occurrence of linear loci for s and 2 nearly throughout the extent of the curves. It is as difficult to even conjecture a reason for this, as it is easy to find reasons against it. The presumptive equation for s is s = 004 (1/6m)* n?, x 34/0 and for n’, if II denotes the product, Mz =e Hence, s = '004 (xn, /6m) * (y: M)* if we disregard the subsidence correction for large coronas ds | dea y*"* in which there is no suggestion of a sustained constancy of the coefficient ds/dz such as the experiments show. To come to some conclusion as to the cause of the discrepancy between the optic value of the nucleation mn’ and the presum- able value n (geometric progression), we may compare the -* This Journal, xxv, p. 224, 1908. C. Barus—Coronas with Mercury Light. 81 successive value n’,,,/n’, = S°,,,/s*, in their relation to y = “771 the exhaustion applied. - The table shows that for very large coronas n’,,,/7', >y, whereas for very small coronas 7’,,,/n’, y calls for some appar- ent production of nuclei at each exhaustion, which is altogether improbable. Therefore, fig. 2 and 3, compare n’ and n, whence n-n' shows the number of nuclei not registered by condensation. For, no matter whether condensation on a given group of nuclei occurs or not, no matter how many nuclei have failed of catching a charge of water, the identical removal of nuclei by partial exhaustion must take place. Such removal is indepen- dent of condensation, and would occur in a dry atmosphere under similar treatment. Consequently y cannot be too large. It may be too small not only from subsidence, but from time losses (decay), or as the result of the purification of air due to turbulent motion across a solid or hquid surface. Consequently nm may be regarded as an interior limit of the nucleation with a probably close approximation to the true value. A comparison of n and n-n’ would, in such a case, show the percentage of nuclei of irregular size which have failed of capture, the number being n-n’. At the same time it must always be recalled, that no ade- quate theory of coronas exists and that therefore the meaning of 7’ is obscure. We must in any case place a part if not all the discrepancy between n and n’ within the province of such a theory as is evidenced by the dependence of aperture on the position of the eye. The need is particularly manifest for the large coronas, in which there is accentuated superposition of interference and diffraction. Small coronas may be tested by coincident results obtained from subsidence and the agreement is then well within the errors of observation. Brown University, Providence, R. I. Am. Jour. Sci.—FourtTH Series, Vou. XXVII, No. 157.—January, 1909. 6 , 82 Scientific Intelligence. SCE Nea EC, INTELLIGENG I. OHEMISTRY AND Puysics. 1. An Attempt to Produce a Compound of Argon.—Assum- ing that any compound which argon might form would be endothermic, and would hence require a large amount of energy and a high temperature for its production, and assuming also that such a compound would need tv be quickly cooled in order to prevent its decomposition, FiscuER and Ixtovici have passed elec- tric sparks, as well as the electric are, between poles of cadmium in liquid argon. Cadmium was selected for these preliminary experiments on account of the fact that Kohlschiitter and Miiller ~ had found that the pulverization of cadmium by the electric discharge was abnormally great in argon gas, as compared with other gases. The argon was prepared from atmospheric air by. the absorption of the other gases by means of calcium carbide. An elaborate apparatus was devised for carrying out the experi- ments, in which it was found necessary to keep the argon at a pressure near that of the atmosphere, for liquid argon boils at —189°6° C. under a pressure of 7607", while it solidifies only 2°70 below this point, and below a pressure of 500™™ liquid argon does not exist. As a result of the passage of electric sparks and the arc through this liquid there was produced a new compound, cadmium nitride, due to traces of nitrogen in the argon used. ‘This nitride, which was mixed with pulverulent metallic cadmium in the product produced by the are, gave off nitrogen when heated in a vacuum, and this nitrogen was found to contain a considerable amount of argon. ‘The authors con- sider this argon as due to adsorption, but propose to continue their experiments under different conditions.— Berichte, xli, 3802. ees OL 2. Huplosive Crystallization.—Having occasion to evaporate a solution containing a sulphate and a thiosulphate enclosed in a bell-jar under a diminished pressure of about 207", WuxsTon found that an apparent explosion violent enough to break the bell- jar had occurred during the night, when the liquid had become very concentrated. Soon afterwards he attempted to crystallize two solutions of a sulphite, which were probably supersaturated, under the same conditions. In this case he saw a part of the contents of one of the dishes violently ejected so that the dish was broken, the other dish was upset, and the whole apparatus | was so shaken that the glass plate upon which the bell-jar rested was broken. The author is of the opinion that crystallization was suddenly induced on the surface of the basin with a con- sequent sudden increase in the vapor-pressure of the surrounding liquid, which under the very low pressure existing in the beli-jar Chemistry and Physties. 83 caused the liquid to boil violently. It appears to the reviewer that this explanation overlooks the chief cause of the sudden boiling, namely, the great amount of heat that is set free by the sudden crystallization of a large amount of salt from a supersatu- rated solution. This sudden warming under low pressure and the presence of much solid salt in the liquid explain satisfactorily these interesting accidents. — Chem. News, xcvill, 27. H. L. Ww. 3. Constituents of Ytterbium.—AvER VON WELSBACH, whose work on the rare earths is well known, particularly his splitting up of old didymium into neodymium and praseodymium, has suc- ceeded in obtaining two earths from ytterbium. This was done by long continued fractionation, particularly of the ammonium double oxalates. He has named the new elements, Aldebaranium and Cassiopeium, Ad and Cp. Their distinguishing feature is In their spark spectra. Their reactions are those of ytterbium, and they cannot be distinguished from one another by any chemical reactions. They form only one oxide, the sesquioxide, which is stable at a red heat. All the salts are colorless if the acid is not colored. The atomic weights found were 172-90 for Ad and 74:23 for Cp. The cassiopeium was not obtained abso- lutely free from the other earth, but it is the author’s intention to repeat the separation with a larger amount of material in order to obtain purer cassiopeium, which he designates as the last in the series of rare earths. It will take six or eight years to complete this tedious task. — Monatshefte, xxix, 2. H. L. W. 4, A New Form of “ Tin Infection.” —It has been known for a long time that metallic tin at low temperatures is subject to a physical change which renders it grey and very friable. For ’ instance, it is said that the tin buttons on the uniforms of Napoleon’s soldiers in the Russian campaign fell to pieces. This behavior was formerly attributed to the simple action of low tem- perature, but in recent times it has been shown that it is due to a recrystallization which can be communicated to any piece of tin at a low temperature, by contact with an affected piece of tin, or, as it may be termed, by inoculation. It has been recently observed by von HasstinGEr that a piece of tinware soldered with tin which had been stored for two years in a place which was always heated in winter showed a dull surface, a crystalline structure under the ' microscope, and a friability corresponding to the change that usually takes place only at low temperatures, It was found further that this material was capable of inoculating unchanged tin, either in the form of ordinary tin plate, tin foil or cast tin, at such temperatures as 7°, 19° and 37° C. The growth of the infected spots of nearly circular form was at the rare of from 3 to 5™™" per day, but it was noticeable that this growth became slow as it extended farther from the inoculated center.— Monat- shefte, xxix, 787. H. L. W. 5. The Heat Evolved by Radium.—A new determination of this constant has been made by von ScuweEiIpLeER and Huss, with the result that 118-0 gram-calories per hour were found. Previ- 84 Scientific Intelligence. ous observers have obtained results varying from 100 to 134 in the same terms. The material used consisted of 1:0523¢. of radi- um-barium bromide, corresponding to °7951g. of radium. The method used was that previously employed by Angstrém for the same purpose. It consisted in placing the radium in a calorimeter, and keeping a second, exactly similar, calorimeter at the same temperature by an electrically heated wire of known resistance. The elevation of temperature thus produced in the calorimeters amounted to 5°5° ©. At first only 40 per cent of the expected heating was produced, probably on account of the escape of some emanation before the beginning of the. experiment, but this increased from day to day. ‘The radium employed was in equi- librium with its decomposition products of short period, but its contents of the products from radium D to radium F was uncer- tain.—Monatshefte, xxix, 853. H. L. W. 6. Positive Rays.—W. Wtsn arranged an apparatus which enabled him to, transmit the canal rays some distance through a capillary tube which was exhausted by means of charcoal and liquid air to a low vacuum. He concludes from his observations that the particles in the canal rays which are least influenced by a magnetic field are those which carry the light emission. More- over, the condition of equilibrium of particles of equal weight— which may be destroyed by a magnetic field—reasserts itself dur- ing the length of path of the rays. The length of this path increases with higher potentials.—Phystk. Zeitschrift, No. 22, Nov. 1, 1908, pp. 765-767. Jes 7. Spectral Intensity of Canal Rays.—The observers of the Doppler Effect in canal rays in hydrogen agree that the displace- ment observed is a band which is separated from the hydrogen line by a space showing no band. J. SrarK and W. STENBERG select the method of viewing the hydrogen line at right angles to the direction of the canal rays, in order to determine its changes in intensity. No Doppler effect of course is seen, but the photometric measures indicate the changes in velocity of the positive particles. They state that the intensity of the canal rays depends upon their velocity. They also find a minimum intensity in the Doppler effect.—Ann. der Physik., vol. xxvi, 1908, pp. 918-926. Stele s. Canal Rays.—J. SvarK discusses the bearing of modifica- tion of the electromagnetic theory of light upon the phenomena of canal rays, especially Planck’s theory of electrical resonators, . and Einstein’s discussion of Lichtquantenhypothese, and believes that this latter hypothesis must stand or fall with further observa- tions of the canal rays.—Physik. Zeitschrift, No. 22, Nov. 1, 1908, pp. 767-773. Tole 9. Potential Measurements in the dark Cathode Space.-— W. WestpHat has confirmed Prof. J. J. Thomson’s theory that the cathode rays are due to impacts of positive particles impinging through the cathode space upon the cathode, and shows, also, that measurements of this potential by means of sounding wires = Chemistry and Physies. 85 does not introduce an appreciable error. He finds that Poisson’s equation is applicable to electric discharges through a gas.— Ann. der Physik, No. 13, 1908, pp. 571-588. Tee. 10. The Elements of Physics; Vol. II, Hlectricity and Magnet- ism; by E. L. Nicuous and W. 8S. Franxiin. New edition, pp. vii + 303, with 196 figures. New York, 1907 (The Macmillan Co.).—This edition of the second volume of Nichols’ and Franklin’s Elements of Physics has been entirely rewritten. No statement is made here, however, concerning a new edition of the other volumes, nor have we seen any announcement elsewhere. The most salient feature of the new edition is the discarding of the traditional treatment of electrostatics, beginning with elec- trostatic attraction and the definition of the electrostatic unit of charge. The authors say: “It seems better to approach this sub- ject from the standpoint of the ballistic galvanometer, inasmuch as, when so developed, the theory of electrostatics is a logical con- tinuation of the foregoing theory of the electric current.” ‘ Most students begin electrical theory at both ends and never reach the middle.” 3 The columns of mechanical and electrical analogies at the end of Chapter VII and at the beginning of Chapter XVI are inter- esting and complete. At the close of the book a list of 145 well- selected problems is given. The volume as a whole is attrac- tively executed and reflects credit both on the authors and on the publishers. ~ : Hi) Ss. Ur 11. A Text-Book of Physics ; edited by A. W. Durr. Pp. xi + 680, with 511 figures and 225 problems. Philadelphia, 1908 (P. Blakiston’s Son & Co.).—This volume is a new departure in the writing of college text-books, in that seven experienced teachers have contributed to its production. The various divisions of the subject and the authors responsible for them are as follows: Mechanics, pp. 1-177, written by A. W. Duff; Heat, pp. 179-281, by K. E. Guthe; Wave Motion and Sound, pp. 283-328, by W. Hallock; Light, pp. 329-474, by E. P. Lewis; Electricity and Magnetism, pp. 475-630, by A. W. Goodspeed; Conduction of Electricity through Gases and Radio-Activity, pp. 631-666, by hk. K. McClung. An obvious danger attendant upon each contributor writing about his special field is that of his treating the subject at such length as to weaken in the student’s mind the contrast between the fundamental facts and those of less significance. In other words, too much detail tends towards a dead level of the special branch under discussion. This danger does not seem to have been successfully avoided, in spite of the fact that the sections written by each author were freely criticized by his six collabor- ators. This objection is especially pertinent to the chapters on Light. In the preface the suggestions are made: “Some may find the material included in the book too extensive for a single course. If so, a briefer course can be arranged by omitting all of the parts in small print together with as much of those 86 Scientific Intelligence. in large print as may seem desirable.” This is unquestionably true from the theoretical standpoint, but we have found by experience that, in general, much culling out of paragraphs is not conducive to the best results on the part of the student. The processes of the differential and integral calculus are used only in the small-print paragraphs and the notation of infinitesi- mals occurs very infrequently in the large-type articles. Never- theless, several useful formule, which in their less rigorous, algebraic clothing are very useful in numerical examples, occur only in the small-print paragraphs in conjunction with the more rigorous, calculus expressions for the same laws. The problems are not numerous and are grouped at the ends only of the chief divisions of the entire subject to which they -appertain. The percentage of rather poorly drawn, shaded figures is appreciably greater in this volume than is usually the case with recent books of college grade. - H. 8. U. Il. Gronoey. 1. Publications of the United States Geological Survey, GrorGE Otis Suiru, Director.—Recent publications of the U.S. Geological Survey are noted in the following list (continued from p. 402 of vol. xxvi): Topocrapuic ATLAs.—Thirty-five sheets. Forio No. 161. Franklin Furnace Folio, New Jersey. Descrip- tion of the Franklin Furnace Quadrangle ; by A. C. Spencer, H. B. Ktmuet, J. EK. Wourr, R. D. Sarispury, and CHARLES PatacHe. Pp. 27, with 6 maps, columnar sections, 15 figures. Burvetins.—No. 347. The Ketchikan and Wrangell Mining Districts, Alaska; by Frep EuGrense Wricut and CHARLES Witt Wricat. Pp. 210; 12 plates, 23 figures, 3 maps in pocket. No. 349. Economic Geology of the Kenova Quadrangle, Ken- tucky, Ohio, and West Virginia; by WiLit1am Ciirron PHALEN. Pp. 158, 6 plates, 21 figures. ; No. 351. The Clays of Arkansas; by Joun C. Brannur, Pp. 247; 1 plate, 20 figures, 1 map in pocket. No. 352. Geologic Reconnaissance of a Part of Western Arizona ; by Wiis 'T. Lex. With notes on the Igneous Rocks of Western Arizona; by ALBERT JOHANNSEN. Pp. 96 ; 11 plates, 16 figures. No. 355. The Magnesite Deposits of California ; by Frank L. Hess. Pp. 67, 12 plates, 4 figures. No. 357. Preliminary Report of the Coalinga O11 District, Fresno and Kings Counties, California ; by Rates ARNOLD and Rosert ANDERSON. Pp. 142, 2 plates, 1 figure. No. 362. Mine Sampling ‘and Chemical Analyses of pe tested by the United States Fuel-testing Plant, Norfolk, Va., 1907; by Joun SHOBER BuRRows. Pp. 23. Geology. 87 No. 369. The Prevention of Mine Explosions, Report and Recommendations; by Vicror WaATrEyNE, Cart MEISSNER and ArTHur DresporovueH; with letter of transmittal by J. R. Gar- HIGLD. -4p. 11. | Also 341-A. Advance chapter on the Coal Fields of North Dakota and Montana from Bulletin 341, Contributions to Econ- omic Geology, 1907, Part II. » Further, Mineral Products of the United States, 1896-1907. Tabulated on large sheet ; also numerous advance chapters from Mineral Resources of the United States, 1907 ; and WatTeER-SUPPLY Papers.—No. 219. Ground Waters and Irri- gation Enterprises in the Foothill Belt, Southern California; by WatteR C. MEnNDENHALL. Pp. 180, 9 plates, 16 figures. No. 220.—Geology and Water Resources of a Portion of South- Central Oregon ; by GreRatp A. Warine. Pp. 86, 10 plates, 1 figure. | gio. 222. Preliminary Report on the Ground Waters of San Joaquin Valley, California; by Water C. MENDENHALL. Pp. 52, 1 plate. . 2. Canada: Geological Survey. A. P. Low, Director, Ottawa.—Recent publications from the Geological Survey of Canada, including the Department of Mines, are included in the following list: (See p. 239, vol. xxvi.) Seventeen maps, giving plans and sections of the Gold Districts of Nova Scotia. | Preliminary Report on a Part of the Similkameen District, British Columbia; by CHartes CamsELt. Pp. 41, with folding map. Depariment of Mines, R. W. Brock, Acting Director. Report on a Portion of Conrad and Whitehorse Mining Dis-- tricts, Yukon; by D. D. Carrnezs. Pp. 38, 8 plates, folding map. Preliminary Report on a Portion of the main Coast of British Columbia and adjacent Islands included in New Westminster and Nanaimo Districts; by O. E. Leroy. Pp. 56, 4 plates, 6 figures, folding map. Report on a Recent Discovery of Gold near Lake Megantic, Quebec ;- by Joun A. Dresser. Pp. 13, folding map. Report on the Landslide at Notre-Dame de la Salette, Liéore River, Quebec; by R. W. Exits. Pp. 10, 7 plates. 3. North Carolina Geological and Economic Survey, JosEPH Hyper Prart, State Geologist. Economic Paper No. 14. The Mining Industry in North Caro- lina during 1906; by J. H. Prarr. Pp. 142, 20 plates, 5 figures. Raleigh, 1907. Bulletin No. 16. Shade Trees for North Carolina; by W. W. AsHE. Pp. 72, 10 plates, 18 figures. No.17. Terracing of Farm Lands ; by W. W. Asuz. Pp. 72, 6 plates, 2 figures. Raleigh, 1908.—The total value of the mineral productions of North Carolina, in 1906, was some $3,000,000, having increased from $1,800,000 since 1901. The most important items, making up two-thirds of the whole, are clay and coal. Following these are 88 Scientific Intelligence. mica ($218,000), copper ($136,000), gold ($122,000) and monazite ($126,000). The present report, by Dr. Pratt, gives an account of the mining industries of the state, particularly as related to gold, mica and monazite. The accompanying bulletins discuss the introduction of shade trees in the cities of the state, and the methods of terracing farm lands. This latter subject is particularly important in a region where the prosperity of the community depends so largely upon the preservation of the natural soil, which, when left to natural processes, soon suffers destructive erosion and is permanently lost. 4. Report of the State Geologist of Vermont for 1907-8. Pp. 302, with 59 plates.-—In the first portion (pp. 1-57) of this volume, the state geologist, Professor G. H. Perkins, treats of the mineral resources of the state, of which marble forms the bulk. In 1906 marble worth nearly four and one-half million dol- lars was produced, and of granite about four million dollars. T. Nelson Dale describes the Granites of Vermont ; H. E. Mervin, Some Late Wisconsin Shore Lines ; C. H. Hitchcock, the Geology of the Hanover, New Hampshire, Quadrangle ; G. H. Perkins, the Geology of Franklin and Chittenden Counties; George EH. Edson, the Geology of the Town of Swanton ; and C. H. Richard- son, the Geology of Newport, Troy and Coventry. An interesting discovery is the finding at St. Albans of a Middle Cambrian fauna with Paradoxides. The fine skeleton of a Pleistocene whale, Delphinapterus vermontanus, long shown at the State Museum, is here described and illustrated at great length by the state geologist. Professor Richardson seems to have fossil evidence indicating that the highly metamorphosed _sedimentaries lying between the eastern foothills of the Green Mountains and the valley of Lake Memphremagog are of Cambro- Ordovician age. The fossils appear to be crushed graptolites. Cc. 8. 5. Thirty-second Annual Report, Indiana Department of Geology, W. S. Buarcu.ey, State Geologist. Pp. 1231, with 22 maps and 55 plates. Indianapolis, 1908.—Nearly 300 pages are devoted to a description of the soils of 17 counties of Southern Indiana by Messrs. Shannon, Lyons, Snider, Ward and Ellis. The vast odlitic limestone industry is described at length by the state geologist and associates. There are also the annual reports of the inspector of mines and natural gas. The chapter on the petroleum industry in 1907 states that since 1891 there have been sunk for oil 24,297 wells into the Trenton limestone and of these 15,210 were producing last January. Last year the total shipped output was nearly five million barrels of 42 gallons each, bring- ing about 88 cents per barrel. About one-half of the book is devoted to “'The Stratigraphy and Paleontology of the Cincinnati Series of Indiana,” by Prof. R. E. Cumings. Sixty-seven local sections are described in detail and the fossils listed for each bed. This is followed by a general discussion of the Cincinnatian series. The greater part of the Geology. | 89 work is devoted to redescriptions of the 422 species collected, most of which are illustrated on 55 plates. The final paper by D. Reddick describes the mushrooms of Indiana. C. 8. 6. Illinois State Geological Survey, Year-Book for 1907 ; H. Foster Barn, Director. Bulletin No. 8, 374 pp., 23 pls., 32 figs. with map. Urbana, 1907.—A number of papers contained in this report have been already published (this Journal, xxiv, 447, xxv, 353-354, xxvi, 166). The remaining papers deal chiefly with economic subjects, including cement materials, clay industries, petroleum, artesian wells, lead and zinc, concrete, land reclama- tion, and valuable studies relating to the alteration of coal, with detailed investigations in certain areas. H. E. G. 7. New Zealand Geological Survey, J. M. Bett Director. The Geology of the Cromwell Subdivision, Western Otago Division ; by James ParKx. Bull. No. 5 (new series). Pp. 86, pls. 20, maps 10, geol. sections 6. Wellington, New Zealand, 1908.—The geo- logical section of the Cromwell area includes, in the Paleozoic sys- tem, two series: the Maniototo series of mica and chlorite schists which have an extreme thickness of 30,000 feet and a remarkably uniform schistosity, sills and dikes being almost completely absent over the wide area of five survey districts; and the Kakanui series of upper schists which are less metamorphosed. The Pliocene is represented by the Manuherikia series of shales and clays, con- taining valuable seams of lignite. The region has been glaciated, as indicated by the moraines and extensive terraces and river gravels. All the glacial and fluviatile deposits are gold-bearing, and the principles underlying the concentration of gold in these gravels are discussed. Petrographic descriptions are given of the following rocks: Chlorite and mica-schist, grey wacke, serpentine, hypersthene-diorite, feldspar-porphyrite, mica-gneiss, biotite- granite, augite-hypersthene-diorite, augite-diorite, hornblende- schist, hornblende-camptonite, sandstone, and chemical analyses are given of altered greywacke, serpentine, mica-schist, and chlorite-schists. Physiographically, the region is a part of the central Otago peneplain, now deeply dissected into “ high table- top mountain ranges intersected by deep water courses and separated from each other by river valleys or cleft in twain by profound gorges”. Mr. Park enters into an extensive discussion of the origin and development of the block mountains, with their intervening basins. H. By G: 8. Report on the Eruptions of the Soufriére in St. Vincent in 1902, and on a Visit to Montagne Pelée in Martinique. Part IT. The Changes in the Districts and the Subsequent History of the Volcanoes; by Tempest ANDERSON. Petrographical Notes on the Products of the Eruptions of May, 1902, at the Soufriére in St. Vineent; by Joun S. Frert. Phil. Trans. Roy. Soe. London, series A, vol. cevili, pp. 275-332, 27 pls. London, 1908. —Dr. Anderson revisited St. Vincent and Martinique in 1907. His descriptions of the changes which have taken place between 1902 and 1907 constitute an interesting study of the secondary 90 Scventific Intelligence. phases of volcanic activity and also of the rapidity of erosion in volcanic materials, and the ease with which vegetation in tropical countries takes possession of a region which is absolutely barren. The sixteen plates from well selected photographs are excellent, and when compared with those taken in 1902 from approximately the same localities, constitute a history of stream development, erosion, and changes in voleanie materials which is very striking indeed. The present volume also contains the “Petrographical notes on the products of the eruptions of May, 1902, at the Soufriére in St. Vincent,” by John 8. Flett. The scientific world is fortunate in having these volcanoes studied by Anderson, La Croix, Hovey, and Heilprin, whose combined reports constitute perhaps the most elaborate treatise on any single volcanic disturb- ance in the world’s history. The bibliography which accom- panies the report is fairly complete, but fails to mention the writings of one of the most industrious students of this district, viz., Angelo Heilprin. ) H. E. G. 9. The Geology and Ore deposits of the Coeur d’ Alene Dis- trict, Idaho ; by FrepERick Lestiz Ransome and FRanK CaTH- CART CaLxins. Professional paper 62. U.S. Geological Survey. Pp. 203, pls. xxix, figs. 23. Washington, D. C., 1908.—This report is of great interest to geologists since it embraces an area of 404 square miles constituting the well known Coeur d’Alene min- ing district of northern Idaho and gives the detailed strati- graphic and structural geology of a portion of a region concern- ing which but.-little has been previously known. The district, as shown by the map, is one of maturely dissected mountainous topography showing a relief between river bottom and mountain top of about 4000 feet. It lies in the midst of a region which while not attaining elevations as great as certain others in the Cordillera, yet is, on the whole, of a particularly wild, rugged and forested character. The sedimentary rocks except for the surface gravels belong entirely to the great Algonkian system known as the Belt, from the earlier studies in the Belt mountains of Montana. The section here attains a thickness of 17,200 feet, the base not exposed and the top removed by erosion. They vary from sandstones to argillites and throughout the greater portion of the system the argillaceous formations show marks of shallow water deposition and subaérial exposure. No great limestone formations such as the two which occur farther east are found in this region and it is concluded that the -sedi- ments came from the west. associates, as could hardly be secured in any other manner. The letters are arranged largely with refereuce to subject matter, but with some regard for chronological order, and the work is illus- trated by a number of portraits not only of Spencer at successive periods of his life, but also of persons with whom he corresponded. In five appendices appear several hitherto unpublished essays, together with lists of his writings (the titles covering fifteen | pages) and the honors which were offered the great scholar by upwards of thirty universities and learned societies. It should be added that these honors were, however, with few exceptions declined. We EG: 100 Screntific Intelligence. "4, American Association for the Advancement of Science.— The sixtieth meeting of the American Association is held at Baltimore, under the auspices of Johns Hopkins University, dur- — ing the week from Dee. 28, 1908 to Jan. 2, 1909; Prof. T. C. Chamberlin of Chicago is President. This is the seventh of the ‘“‘ Convocation week” meetings; some twenty-four affiliated societies meet at Baltimore at this time. A Darwin commemo- rative meeting takes place on January 1, under the combined auspices of the Association and the Society of Naturalists. Also a meeting of the American Health League is called for Dee. 31, in connection with Section I of the Association, as a symposium a Public Health:? 5. Lhe Nature of Enzyme Action; by W.M. Bayuiss. Pp. 90. London, 1908 (Longmans, Green “& Co. ).—This is the first of a series of monographs on bio-chemistry planned to supplement the current text-book treatment of topics in rapidly developing departments of this science. Enzyme action is shown to be a type of catalytic reaction the features of which are subjected to critical analysis by the author, and compared with the behavior of other catalysts. Special consideration is devoted to the nature of colluids as exemplified in enzymes, to the reversibility of enzyme action, and to changes 1n the rate of reactions as affected by them. Other appropriate details, such as the relation of the enzyme to its substrate, the influence of “co-enzymes” and “ anti-enzymes, ” temperature and concentration, etc., are also discussed. ‘The treatment is quite original. L. B. M. 6. Rivista di Scienza.—This valuable “ International Review of Scientific Synthesis,” commenced in 1907, has now completed its fourth volume. A recent number includes eight articles, among which may be mentioned the following: G. H. Bryan on the diffusion and dissipation of energy ; W. Ritz on the role of the ether in Physics; G. Haberlandt on motion and sensation in the plant world; G. Schiaparelli, on the astronomy of the Bablyonians. B. G. Teubner’s Verlag auf dem Gebiete der Mathematik Naturwissen- schaften and Technick nebst Grenzwissenschaften. Mit einem Gedenktage- buche ftir Mathematiker und den Bildmissen von G. GALILEI, etc. Dem IV. Internationalen Mathematiker-Kongress in Rom. 6-11. April 1908. Pp. 392. OBITUARY Dr. Otiver Wotcorr Gises, from 1863 to 1887 Rumford Professor of Applied Science in Uarvard University and for thirty years an Associate Editor of this Journal, died at his home in Newport, R. I., on December 9, in his eighty-seventh year. A notice is deferred until a later number. Professor Wittiam Epwarp Ayrron, the eminent English engineer, died on November 8, at the age of sixty-one years. New Circulars. 84: Eighth Mineral List: A descriptive list of new arrivals, rare and showy minerals. 85: Minerals for Sale by Weight: Price list of minerals for blowpipe and laboratory work. 86: Minerals and Rocks for Working Collections: List of common minerals and rocks for study specimens; prices from 1% cents up. , Catalogue 26: Biological Supplies: New illustrated price list of material for dissection; study and display specimens; special dissections; models, etc. Szxth edition. : Any or all of the above lists will be sent free on request. We are constantly acquiring new material and publishing new lists. It pays to ‘be on our mailing list. Ward's Natural Science Establishment 76-104 CoLiEeGE AVE., Rocurstmer, N. Y. Waro’s Natura Science EstastisHment A Supply-House for Scientific Material. Founded 1862. Incorporated 1890. DEPARTMENTS : Geology, including Phenomenal and Physiographie. Mineralogy, including also Rocks, Meteorites, etc. Palaeontology. Archaeology and Ethnology. — Invertebrates, including Biology, Conchology, etc. Zoology, including Osteology and Taxidermy. Human Anatomy, including Craniology, Odontology, etc. Models, Plaster Casts and Wall-Charts in all departments. Circulars in any department free on request; address Wards Natural Science Establishment, 76-104 College Ave., Rochester, New York, U. S, A. CONTENTS. Arr. I.—Diopside and its Relations to Calcium and Magne- sium Metasilicates; by E. T. Atuen and W,. P. Wurrs, With Optical Study ; ; by F. E. Wricst and EH. S: Larsen. (With Plate I) Il.—California Earthquake of 1906; by G. K. GiLBert? ___- Ill.—Descriptions of Tertiary Insects ; ; by T. DAS Cogm EREEL?:< Part oes ee sini = a ed ee IV.—Electrolytic Estimation of Lead and of Manganese by the Use of Uhe Filtering Crucible ; by F. A. Goocn and V.—Specific Radio. Activity of Thorium and its Prodaete by G. C. AsHMan VI.—Coronas with Mercury Light ; SCIENTIFIC INTELLIGENCE. Chemistry and Physics — Attempt to Produce a Compound of Argon, FISCHER and In1ovict: Explosive Crystallization, Weston, 82.—Constituents of Ytterbium, A. v. WELSBACH: New Form of ‘‘ Tin Infection,” von Hass- LINGER: Heat Evolved by Radium, von ScHWeEIDLER and Hess, 83.— Positive Rays, W. Wien: Spectral Intensity of Canal Rays, J. STarK and W. STENBERG: Canal Rays, J. Stark: Potential Measurements in the dark Cathode Space, W. WrstTPHAL, 84.—EHlements of Physics, NicHous and FRANKLIN: Text-Book of Physics, 89. Geology—Publications of the United States Geological Survey, 86.—Canada Geological Survey: North Carolina Geological and Economic Survey, 87.—Report of the State Geologist of Vermont for 1907-8: Thirty- second Annual Report, Indiana Department of Geology, 88.—Iilinois State Geological Survey, Year-Book for 1907: New Zealand Geolog- ical Survey: Report on the Eruptions of the Soufriére in St. Vincent in 1902, and on a Visit to Montagne Pelée in Martinique, T. ANDERSON and J. S. Fietrt, 89.—Geology and Ore deposits of the Coeur d’ Alene District, Idaho, 90. —Geologie der Steinkohlenlager, DannuNBERG: Geology of Coal and Coal- mining, W. GIBSON: Physical History of the Earth in Out- line, J. B. Bappitr: Triassic Ichthyosauria, with special reference to American Forms, J. C. Merriam, 91.—Fossil Vertebrates in the American Museum of Natural History, Part I— Fishes, L. HussaKxor, 32.—Conrad Fissure, B. Brown: Four- horned Pelycosaurian from the Permian of Texas, W. D. Marriew : Osteology of Blastomeryx and Phylogeny of the American Cervide, W. D. MatrHew: Rhinoceroses from the Oligocene and Miocene deposits of North Dakota and Montana, E. DouGuass, 93,— Fossil Horses from North Dakota and Montana, E. Dovenass: Some Oli- gocene Lizards, EK. DouGuass: Preliminary Notes on Some American Chalicotheres, O. A. PETERSON, 94. ' Botany and Zoology—Harvard Botanical Station in Cuba, 94.—Handbuch der Bliten-biologie, P. Knut : Convenient Clearing and} Mounting Agent, 96.—Economic Zoology : Text-book of the Principles of Animal Histology, U. DaHLGREN and W. A. Kepner: Archiv. fiir Zellforschung, R. GOLp- ScHMIDT : Ueber die Hibildung bei der Milbe Pediculopsis graminum, 97. Miscellaneous Scientific Intelligence—Artificial Daylight for Use with the Microscope, F. E. Wricut: lon; A Journal of Electrotonics, Atomistics, Tonology, Radio-activity and Raumchemistry, 98,—Life and Letters of Herbert Spencer, D. Duncan, 99.—American Association for the Advance- ment of Science: Nature of Enzyme Action: Rivista di Scienza, 100. Obituary—O. W. Gipps: W. E. Ayrron, 100. . Cyrus Adler, — Librarian U. S. Nat. Museum. 0 =a ' VOL. XXVIII. . FEBRUARY, 1909. Established by BENJAMIN SILLIMAN in 1818. THE AMERICAN JOURNAL OF SCIENCE. » = Eprrop: EDWARD S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, or CamBrwce, Proressorss ADDISON E. VERRILL, HORACE L. WELLS, _L. V. PIRSSON anp H. E. GREGORY, or New Haven, Proresson GEORGE F. BARKER, or PHILADELPHIA, Proresson HENRY S. WILLIAMS, or Ituaca, Proressorn JOSEPH S. AMES, or Battimore, Me. J. S. DILLER, or WaAsHINGTON. Ce a eee Se i a a FOURTH SERIES No. 158—FEBRUARY, 1909. eee VOL. XXVII-[WHOLE NUMBER, CLXXVIL] WITH PLATES II-IV. NEW HAVEN, CONNECTICU aig £2 ODF: THE TUTTLE, MOREHOUSE & TAYLOR CO., PRINTERS, 123 TEMPLE/STREET. ; ; Pi Published monthly. Six dollars per year, in advance. $6.40 to countries in the Postal Union ; $6.25 to Canada, Remittances should be made either by money orders, registered letters, or bank checks (preferably on New York banks), RARE CINNABARS FROM CHINA. During the past month our correspondent in China ran across fine, remarkable specimens of these Cinnabars and we immediately ordered them secured for us, and they will reach us about the time this Journal is published. Write for illustrated pamphlet and particulars. NEW ARRIVALS. Euclase, Capo do Lane, Brazil; Chalcocite, Bristol, Conn.; Columbite, _ Portland, Conn.; Iolite, Guilford, Conn.; Monazite, large loose xls. and in matrix, Portland, Conn.; Uraninite, crystal in matrix, Portland, Conn.; Eglestonite, Terlingua, Texas; Patronite, S. A.; Benitoite, San Benito Co., Cal.; Neptunite, Cal.; Crookesite, Hedenbergite, Sweden; Lievrite, Elba; Polybasite, Hungary and Durango, Mexico; Josephinite, Oregon ; Herderite, Poland, Maine ; Smithsonite, Kelly, N. M.; Californite, Tulare Co., Cal.; Cobaltite, loose crystals and in matrix, Cobalt, Ont., and Tunaberg, Sweden; Apatite, Auburn, Maine ; Vivianite, large crystals, Colo.; Vanadi- nite, Kelly, N. M.; Olivenite, Utah ; Sartorite, Canton Wallis; Jordanite, Binnenthal ; Mohawkite, Algodonite, Domeykite, Michigan; Crocoite, Sibe- ria and Tasmania ; Cinnabar, Cal., Hungary and China; Dioptase, Siberia ; Diopside, with Essonite, Ala, Piedmont; Embolite, Australia; Gypsum, twin crystals, Eisleben, Thuringia; Diamond, in matrix, New Vaal River Mine, South Africa; Argentite, Mexico; Freiberg, Saxony; Pyrargyrite, Saxony and Mexico; Wulfenite on Aragonite, Organ Mts. N. Mexico; Celestite, Sicily ; Pyromorphite, Ems, Germany, Phoenixville, Pa.; Miller- ite, Antwerp, N. Y.; Sylvanite, Colo.; Tellurium, Colo.; Tourmalines, new find, San Diego Co., Cal.; Tourmalines, beautiful sections from Brazil; Bro- chantite on Chrysocolla, Utah; Pink Beryl, small and large, Mesa Grande, Cal.; Kunzite, small and large, Pala, Cal.; Sphene, Binnenthal ; Titanite, Tilly Foster, N. Y.; Tetrahedrite, Utah and Hungary; Realgar, Hungary ; Opal, Caribou River, Queensland ; Octahedrite, var. Wiserine, Binnenthal ; Heulandite, Iceland; Torbernite, Eng.; Bismuth, native, Cobalt, Ont. and Conn.; Silver, native, polished, Ont.; Emerald, loose and in matrix, Ural and Bogota; Topaz crystals with rare planes, Ural; Zircon crystals, loose, Ural; Green and Cinnamon Garnets, Minot, Maine; Vesuvianite, Poland, Maine, Italy and Tyrol; Zeolites, beautiful specimens from Erie Tunnel, Patterson and Great Notch. CUT GEMS. * Garnets, green and red; Aquamarines; Zircons, all shades; Sapphires, all shades ; Star Sapphires and Star Rubies ; Chrysoberyl, Cats-eye ; Spinels, all shades; Topaz, pink, blue, brownish and golden color; Pink Beryl; Sphene; Tourmaline, all shades; Amethyst, Siberia, royal purple color; Andalusite; Star Quartz; Peridote; Opal matrix, Mexico and Australia ; Precious Opal, Australia, Mexico and Hungary ; Hyacinth ; Turquoise, Mex- ico and Persia; Kunzite; Reconstructed Rubies and Sapphires; Emeralds ; Opal Carvings, such as pansies, vine leaves with bunches of grapes, and other small Opal novelties; Antique and Modern Cameos; Antique, Mosaic and other semi-precious stones. Let us know your wants, and we will send the specimens on approval to you. Write for our new circular today. A. H. PETEREIT, 81—83 Fulton Street, New York City. THE AMERICAN JOURNAL OF SCIENCE POUR th SERIES .| ee Arr. VII.— Revision of the Protostegide; by G. R. Wreranp. (With Plates II-IV.) [Contributions from the Paleontological Laboratory of Yale University. | Tuerre is no family among all American fossil turtles which, following the discovery of its initial type, has so steadily yielded new forms and additions to our knowledge of the structure and history of marine turtles as the Protostegide. True enough, no further members of the family were noted and few specimens were collected for twenty years after Cope’s original discovery of Protostega gigas; but then came the addition of the related genus Avchelon from the Pierre Cre- taceous in 1895, smmce which time scarcely a year has passed without yielding new data to the structure, extent and signifi- cance of the Protostegide. Indeed, even before the discovery of Archelon the attention of the brilliant and incisive Baur had been turned to Protos- tega; and since then Hay, Case, Williston and Wieland have all contributed in turn to the literature of the Protostegida,— while in Europe Dollo has published papers of the greatest supplemental interest dealing with the origin of marine turtles. Furthermore the collection of the splendid cotypes of Pvo- tostega gigas showing the complete limb structure, now in the Carnegie Museum of Pittsburg, and more recently the mount- ing for exhibition of the huge type of Archelon ischyros in the Yale Musenm, have contributed much toward the increas- ingly accurate picture of the Protostegidee. With the descrip- tion of new species, meanwhile, and the appearance of the great volume of Hay—easily the foremost contribution to the literature of the Testudinata yet made—it is already evident that the Protostegidze include a series of forms of the greatest structural interest, and that further additions to the family are Am. Jour. Sc1.—Fourts Serres, Vou. XX VII, No. 158.—Frsrvuary, 1909. 8 102 G. R. Wieland—On Marine Turtles. certain to be made. Moreover, to all these newer facts and viewpoints we are enabled to add the description of a new species, calling for analysis of the group. To these forewords to the present revision I wish to add praise for the painstaking labor bestowed upon the mounting of Archelon by the Yale Museum preparator Mr. Hugh Gibb. Likewise we are indebted to the rare skill of the well known scientific illustrator and artist Mr. R. Weber for the illustrations folowing. CHELONIOIDEA Baur. SUPERFAMILY OF THE CRYPTODIRA. A parieto-squamosal arch ; palatine foramen and free nasals sometimes present (Desmatochelyidee); fourth cervical cyrtean, with the centra of the sixth to eighth less modified in Creta- ceous than in recent forms. The five great marine families, namely, the Cheloniide, Protostegidee, Desmatochelyidz, Toxochelyide, and Dermo- chelyidee, all doubtless independently acquired their equipment for life in the sea.” Family Protostegide Cope. Turtles with highly specialized thalassic humeri, but with three or more claws. A leathery hide and osteodermal arma- ture evidently present. Carapace usually greatly reduced in later forms, the disk investing less than one-half the rib lengths. Plastron not markedly reduced. Peripherals serrate to strongly digitate on their interior borders; intra-peripheral dermogene ossicles sometimes present (known in Avrchelon only). Plastron very large, dactylosternal, with prominent fortanelles ; epiplastra small, out-turned, separate, and wholly supported by the very large T-shaped entoplastron; hyo- and hypoplastra moderately digitate (Protostega advena) to strongly digitate (Archelon); xiphiplastra short and bowed. Pelvis with obturator foramina enclosed by complete ischio-pubic border. Coracoid extending all the way back to the pre-pubis except possibly in P. Coper. Skull large; temporal region broadly roofed over; descending processes of parietals ; ant- orbital projection marked ; quadrato-squamosal vertex much depressed ; narial aperture more or less upturned ; choanee far forward, opening free behind vomer. Genus PrRoTrosTeGa Cope, 1872.’ Premaxillary beak less developed than in Archelon , maxilla with rather broad grinding surface, which extends backward to behind front of orbit. Lower jaw with rami early coossi- G. R. Wieland—On Marine Turtles. 103 fied. Neuralia normal so far as yet seen, and without median pits or grooves. . Radial process of humerus large and project- ing. Species of Protostega. A. Niobrara Cretaceous :— 1. A medium-sized to large turtle, with a thin cara- pace investing one-third the rib lengths, and interior borders of marginals splitting into medium-sized digitations. P. gigas. 2. A small turtle, with more than half the rib lengths expanded and with less reduced plas- tron than the preceding ; the hyo- but not the hypoplastra meeting on the median line; xiphiplastrals only shghtly bowed ; marginalia heavy and without digitation of interior borders. P. advena. 3. A medium-sized turtle, with a comparatively thick carapace investing the proximal half of the ribs; plastral form nearly as in P. gigas but with more numerous digitations and smaller fontanels; marginal borders serrate rather than smooth ; limb bones relatively short and small. This form has the heaviest shell of any Pro- tostegid. The carapace is little more, and the plastron less reduced than in the Cheloniide. P. Copei. 4. A large turtle, with xiphiplastra nearly joined on the median line and epiplastral pittings on outer anterior projection of hyoplastra. P. potens. B. Pierre Cretaceous :— 5. An immense turtle, with neuralia like P. Copez, but humerus without a markedly strong radial process ; marginalia strongly digitate on inte- rior borders. P. (Archelon) Marshii. Genus ArcHELoN Wieland, 1896.° Premaxillary beak greatly developed and strongly decurved ; crushing surface of upper jaw set far forward and limited to vomero-maxillar region; lower jaw with rami not codssified until old age. Neuralia greatly reduced, to partly abseut anteriorly, and replaced by epineuralia with a deep median suleus nearly continuous to the eighth true [underlying] neural; tenth rib relatively large, free, and extending out to marginalia. Radial process of humerus weak. Archelon ischyros from the uppermost Pierre Cretaceous of the valley of the South Fork of the Cheyenne River is the only species. 104 G. R. Wieland—On Marine Turtles. Protostega Copei sp. nov. (Figures 1-4). A new species, which may be appropriately named for the illustrious discoverer of the Protostegidee, is indicated by the most complete and best conserved specimen referable to its family, thus far obtained. This splendid fossil is from the Niobrara chalk of the Hackberry Creek Valley, Gove county, Kansas, and was found in the summer of 1905, by the veteran collector and explorer, Mr. Charles H. Sternberg. Brew: FIGURE 1.—Protostega Copei. Photograph of skull and lower jaw of type as mounted in the Yale University Museum by bringing together the disso- ciated and for the greater part but little crushed cranial elements. One- fourth the natural size. Only minor portions of certain boundaries had to be restored. A little atvention will at once reveal the limiting sutures of the premaxillary, max- illary, frontal, post-frontal, parietal, jugal, post-frontal and squamosal. Only the boundaries of the quadrato-jugal are generalized. The premax- illary is a little crushed to the left, and the most striking feature is the low-set position of the squamosal, which is but little if at all exaggerated. Cf. figure 6. Not only is the present type one of the most complete of fossil turtles, but more than any other known specimen of Protostega, it permits exact comparison with Archelon, being for the most part free from the crushing which so often obscures the characters of the otherwise fine material from the G. R. Wieland—On Marine Turtles. 105 Kansas chalk. Owing to this freedom from crushing, it has _ been possible to restore with approximate accuracy the outline of the skull, carapace, and plastron, although all the elements of the entire skeleton were dissociated during erosion from their matrix, those recovered being as follows: Skull, with lower jaw,—nearly complete, one squamosal and certain minor portions only missing. Carapace: Nuchal; first to fourth neuralia; pygal; fairly complete series of ribs; first and second marginalia of both sides, with third and fourth of right side. Plastren - Alee of the entoplastron; hyoplastron of right side; hypoplastra and xiphiplastra complete. Shoulder girdle: Both humeri and the procoraco-seapulars, with coracoid of right side only. Pelvis: Only the right ischium missing. The chief parts lacking, therefore, are the radius and ulna, the femora, and the bones of the hands and feet. The dissociated elements of the cranium, as brought together and mounted with the lower jaw, afford the most satisfactory representation of a Protostegan skull thus far seen. In fact, the result displayed by photographic figure 1 must be of nearly the true form, since in addition to the presence of the lower jaw and nearly all the exterior elements, the main outline is further confirmed by the pr actically complete pala- tines, pterygoids, and quadrates. Only in the interior of the skull are clear characters lacking; for instance, the descending process of the parietals, noted by Dr. Hay in Protostega advena, cannot be observed. In the main, the present fine cranium merely serves to corroborate the characters of the Protostegan skull, as already determined, and to bring out more clearly the major ‘differences from Apchelon. Thus, the strongly decurved beak and the upturned nares of the latter genus are absent, the outlines being more like those of cther sea-turtles, with the orbits fairly well forward. The low-set squamosal, which certainly sent up a process along the posterior border to meet the parietal, how- ever, 1S a family characteristic. The general outline reminds one not a littlé of the skull of Colpochelys Kempi Garman. Interiorly, there isno great conelike palatal pr ojection of the vomer, as seen in Ar chelon. While the present species is here defined as new, there is no very marked character not possessed by Protostega ¢ Jigus, spe- cific differences being mainly exhibited by the smaller limbs and the heavier carapace and plastron now to be described. Carapace.—Hitherto it has not been possible to gain a satisfactory picture of the shell of any species of Protostega. All the specimens known have either lacked a large part of the 106 G. R. Wieland—On Marine Turtles. neuro-pleural series, or they have been so badly crushed as to, render the general form and structure more or less doubtful, as in the case of the Carnegie Museum specimen that yielded such clear testimony to all the characters of limb organization ; and even in the present instance the evidence is not so convine- die 2), FIGURE 2.—Protostega Copei, 1/7 natural size. Carapace of the type as mounted in the Yale University Museum, from little crushed but dissociated elements lacking those portions marked by an (x) or else given in dotted outline. The portions actually present thus include a fine nuchal (with a nether process), the four first neurals and pygal with the three first margin- als perfect, together with eight pairs of pleuralia. The disk is then correctly indicated ; but concerning doubts as to the existence of a large ninth pair of ribs in contact with the marginals consult the text. ing and complete as in Avchelon, where the series of ribs is not only entire, but articulated. Nevertheless, owing to absence G. F. Wieland—On Marine Turtles. 107 from crushing, splendid conservation of all surface features, and the presence of a nearly complete series of ribs, with the nuchal, the anterior neurals. and important marginals com- pleting all the frontal border, the present carapace must be regarded as a magnificent specimen. In fact, the only structural point in the restoration here given, which awaits confirmation or disproval by future discovery, is the degree of development exhibited by the tenth pair of ribs. They are represented free, as in Archelon in figure 2, and such ribs extending out to meet the final marginal are regarded as a prob- able family distinction. It may be, however, that placing the proximal portion of the right fifth pleural as assigned and then restoring a sixth and a seventh pleural on the left side are not warranted. In such a contingency two suppositions are, therefore, open, as follows: (a) The pair of ribs shown as the tenth may be really the ninth, and the true tenth pair of ribs may not be present, perhaps being only slightly smaller than those shown in the restoration, but passing out to meet the marginals. Such being the case, the only error made is in placing the pleuralia, from the fifth pair of ribs on, one number too far back; (6) An unrecovered tenth pair of ribs may be reduced, as in the Cheloniidse, and may not have passed out to the final marginal. In this case, the post-fifth pleuralia would not only be one number too far back, but the carapace would be as here represented several centimeters too long. If either error has been made, the former seems by far the more probable. | The neuraha are heavier than in Protostega gigas, and form a strong unbroken mid-ridge of normal Testudinate form in sharp distinction to the epineural grooving and anomalous structure of Archelon. Though it is to be noted that on the first neural, the second and third, evidently on the fourth and fifth, and probably on the missing eighth and ninth, there is a strong accentuation of the mid-ridge, suggesting the appear- ance seen in Zoxochelys Bawri. In the latter form, however, this feature is due to discrete epineural ossicles, while in P7ro- tostega Coper there is no evidence of osteodermal elements. Nor are there any hornshield groovings; on the contrary, the evidence is always to the effect that the Protostegide were enveloped in a leathery hide. Fortunately, the nuchal is sufficiently complete to show the entire outline as a heavy normal element much as in Osteo- pygis, except that a prominent nether process is present. The first marginals, which are rather short and flat elements, are quite complete, as is also the rather long second marginal of the left side, with the distal half of that of the right side. On the latter may be traced with precision, one after the other, 108 G. R. Wieland—On Marine Turtles. the articular digitations and grooves corresponding to those of the next member of the marginal series, namely, the third, which is also complete and is followed by a fourth in equally good preservation. J am thus explicit, because it is important to note that all the anterior border of the carapace is indicated with certainty, and shows the presence of a peculiar upturning Fie. 3. LEN FIGURE 3.—Protostega Copei. Plastron of the type x 1/7 nearly. The hypo-xiphilastre are especially well conserved, and the left hyoplastron in fair condition. The right hyoplastron and portions of the T-shaped epiplas- tron are not present; and as indicated in the figure, the ends of most of the digitations of all the elements are missing. Nevertheless the plastral form is quite accurately indicated in its entirety by the original specimen as here outlined. of the portion of the carapacial edge formed by the junction of the third and fourth marginals. Evidence is here furnished that the strong anterior and much upturned prolongation of the third marginal of Archelon was an articulating portion G. R. Wieland—On Marine Turtles. 109 rather than a spine; and use has been made of this fact, although it might have remained in doubt but for the exact testimony of the present fine specimen. The interior borders of these marginals, however, do not have the strong digitation seen in Archelon, being only slightly serrated. Iie. 2h Ficure 4.—Protostega Copei. Shoulder girdle with humeri and the pelvis of the type x 1/7. The only portions restored are the left coracoid and the right ischium. These elements belong to the very same individual as the skuil, carapace and plastron shown in figures 1-3. [It is likely that consonant with the heavy carapace the limbs were shorter than in P. gigas, and that the coracoids did not actually come into contact with the ecto- pubis. ] Protostega Coper was not so orbicular a form as Archelon ischyros, and its plastron was relatively much shorter. As to the elements other than those now described, it appears neces- sary only to state that the accompanying illustrations suffi- 110 G. R. Wreland—On Marine Turtles. ciently exhibit not merely their characters, but their chief dimensions. Certain measurements, however, are appended, as follows : Length of cranium from snout to condyle (accurate) _. 24:0°™ Greatest width of cranium across the condyles (close)__ 20°0 Length of lower jaw (on median lime) 2). s2. 15:0 enethsof carapace (estimated). = She es ee eas 80°+ Greatest, length: of plas trol mee erect ee ee 63°5 + Greatest. width: of; plastrem Sse eee oe eee 66:0 Greatest thickness of plastral elements measured through their centers of ossification : ; Kutoplastron.35- 2 Gee 2 eee ee pee Hyoplastron ..55. 25 2 2 ee eee Hypoplastroms) 2. ee ee Aiphiplastrons 22s Vos ee ee een 13° —<—— SSS 8 SS SSSSSS= FIGURE 0.— Protostega(Archelon) Marshii. Right third marginal x4. Dorsal view to the left, and ventral view showing large pit for the second rib to the right. [{Dactylations should be represented as distinctly acuminate, but not much longer.| Observe, that as proven in Protostega Copei, articulation with the second marginal was formed by the long upward and forward projection, resulting in abrupt change in direction of the marginal line at the humeral notch, as revealed further by the figures of the entire skeleton. Protostega (Archelon) Marshii Wieland” (Figure 5). In this Journal for April, 1900, I gave a brief description of a new species of Archelon, which was based on the portion of a skeleton collected by me in 1898, on the left bank of the Cheyenne River. Until further material is found, as will with certainty transpire, the fragmentary condition of the present remains will scarcely justify much work upon them by a pre- | G. R. Wieland—On Marine Turtles. WI parator; nevertheless, the species represents an important fossil ty pe. A reéxamination, of the specimen confirms the characters given, namely, a relatively short humerus and great thickness of the plastron, the latter being half as thick again as that of Archelon. As it is probable that the present ‘turtle was not “quite as large as A. ischyros, type (3°-4 m.—11 feet long), however, it may be that its plastron was proportionally twice as thick as that of the latter species. A fine third marginal of the right side shown in figure 5 is also present, and with it are articulated the keels of the more fragmentary fourth and fifth marginals. These elements are of much the same form as in A.zschyros, type, and although relatively heavier than in that species do not show the great disparity in weight noted in the plastron. More obvious differ- ences of taxonomic bearing, however, are exhibited by a frag- mentary, though otherwise finely conserved neural from near the middle of the neural series. This lacks the groove so highly characteristic of Archelon, and has a strong and continu- ous median ridge precisely like that in Protostega Coper. It therefore becomes necessary to transfer the present species from the genus Archelon to Protostega, where it holds a posi- tion of importance, as exhibiting not only the continuation of the latter genus from the Niobrara into the Fort Pierre, with marked increase in size, but, as far as we know, represents the closest structural approach of the genus Protostega to Archelon, thus far observed. The Mounted type of Archelon ischyros (with Figures 6-12, and Plates I[-IV). All the material thus far referred to the genus Avrchelon has been discovered and collected by myself during the past four- teen years. ‘The original type of Archelon ischyros was found in the brakes of the south fork of the Cheyenne River, about five miles west of the mouth of Rapid Creek, Custer county, South Dakota, in August, 1895. Though a remarkably com- plete fossil, it ‘lacked the ‘skull, which, however, was supplied by an excellent younger specimen with a fine cranium and the lower jaw in place, obtained in 1897. This is here shown by the photographic drawing, figure 6. In 1898, the related type Protostega (Archelon) Marshir was procured from the same horizon as the specimens of Archelon, but on the east bank of the Cheyenne, in the Pine Ridge Indian reservation. Later still, in 1902, a large individual of A. ¢schyros, nearly identical in size with the original type, was collected at a point several miles farther south, on the west bank of the Cheyenne. This 112 G. R. Wieland—On Marine Turtles. specimen has been of considerable value in showing the more important carpals in natural position, and in yielding additional finger bones and the epiplastron. A well-conserved lower jaw with fully codssified rami accompanies it. Like the type, it was completely imbedded in one of the lenticular masses of marl or clayey limestone common in the Pierre, but as this was much checked by cleavage planes there has been consider- able shifting of parts. The specimen, while good, is not com- parable to ‘the original type, which, barring the lack of the skull (destroyed by erosion), is one of the finest of all oreat fossil vertebrates. It was but little crushed, and nearly all the parts present were in their normal position. In addition to the examples mentioned, fragmentary portions — of other specimens were obtained at different times, all per- taining to the uppermost one hundred feet of the Pierre, and all from within an area of about eight square miles. The best skeletal conservation was found in the bluish clays of the upper thirty feet of the Pierre, as covered by the Oligocene overlap in the Cheyenne River valley; but most unfortunately a broad Oligocene river, the clearly marked bed of which I definitely located west of the Cheyenne, scooped out of these Pierre strata exactly the portion that must once have con- tained the most numerous and the best turtles, as indicated by frequency of occurrence as well as fine conservation on both banks of the old Oligocene valley. The various specimens of Archelon have been made the sub- ject of five contributions to this Journal. * * ™". These par- tial descriptions have been repeated in a summarized abstract, with certain additional interpretations and views, in Dr. Hay’s great volume on the “ Fossil Turtles of North America.” ” It does not therefore seem necessary again to repeat the preliminary descriptions, except in so far as needed to call attention to inaccuracies disclosed by the final mounting of the type specimen, together with the great additions to our - knowl- edge of Pr otostega made during the past half dozen years. It is the present purpose to give in concise form the features of this greatest of marine turtles disclosed by new discoveries and by mounting, which always sheds new light on the char- acters of a fossil vertebrate ; and especially to give the facts of classificatory value, together with a discussion of relationships. The Skull (fizure 8). —It is to be hoped that a second skull may be recovered. Thus far only the type skull and one addi- tional lower jaw have been found ; hence, it is not possible to add to the earlier descriptions except in ‘wholly minor points of interpretation. Moreover, abstracts of these descriptions with figures are given in admirable form in Hay’s work previ- ously cited, a work which ever y student of the Testudinata must G. R. Wieland—On Marine Turtles. 113 find indispensable. It may, however, be stated that in the res- toration, Plate IV, the skull undoubtedly shows the exact proportions of the supra-occipital, this being an improve- ment upon the earlier figures. The Vertebral Column.—The fact that the vertebral column of Archelon is so nearly complete and uncrushed, with nearly all the elements in undisturbed natural position, gives to the restoration high value. Only the four proximal cervicals and a few of the smaller caudals from near the tip of the tail are missing, while from the eighth cervical to the fifth caudal, Hie. 6: FIGuRE 6,—Archelon ischyros. Skull of cotype shown about 1/8 natural size. The bounding sutures of all the exterior elements may readily be distinguished. [The restored supra-occipital crest, perhaps, is shown .too slender.| The low set squamosal is, in comparison with P. Copei and P. gigas, seen to be a family character of the Protostegide. inclusive, all the vertebrae are complete and in natural contact. Further, in the large specimen collected in 1902, the fourth cervical is present and of the normal or cyrtean form common to all marine 'Testudinata. In Archelon, the cervicals succeeding the fourth are ccelo- cyrtean, with the inferior sides of the centra heavily double- keeled. The valley between the keels is broad and shallow. Neither in form nor size is there much variation in the distal cervical centra. Aside from strength and great size, the dorso- 114 G. R. Wieland—On Marine Turtles. sacral series presents no marked peculiarity, while the caudal series is rather short. The arches of the first eight to ten caudals are free, but those of the: remainder of the series are strongly fused to their centra. It is not likely that the tail could have been so freely moved as might be implied from the over strong curve in the restoration. EG Rae Figure 7.—Archelon ischyros, x 1/36. Dorsal view of original type. It is not necessary to give in detail the exact outline of the restored portions. The skull is outlined from a cotype, and the right hind flipper shown in the normal outline was not present beyond the proximal half of the tibia and fibula, having, as explained in the text, been bitten away in the early life of the turtle. Note on the mid-line following the nuchal seven larger plates followed by four smaller ones and then the pygal. All these eleven plates intervening between the nuchal and the pygal are adjudged to be epineurals seated on the greatly reduced neural series which did not, as in all other turtles except Dermochelys, normally come into view at all. Observe the nine pairs of fully developed ribs, of which the first large pair is the second, the small first pair not coming into view. Infra- and supra- peripherals not indicated. The Curapace.—The nearly orbicular form of the carapace is a striking feature. The nwchal is very large and very thin, G. R. Wieland—On Marine Turtles. 115 especially in the lateral portion, indeed so thin as to suggest the necessity for strengthening by overlapping dermal ossifica- tions. The anterior edge is strongly concave, being sharp, not rounded, in the middle region. The nether or cervico-neural articular process is prominent; it takes the form of a heavy trapezoidal ridge, longest in front, with a keel-like buttress radiating from all four corners. The medial elements of Archelon are anomalous and require discussion as well as description. At first sight one would certainly say that there is a series of seven larger neurals fol- lowing the broad thin nuchal, with four much smaller neurals preceding a single pygal element and making eleven neurals in all. On closer inspection, however, it is found that despite the fact that the neural region of Protostega is of simple and normal structure there is in Avchelon a more compiex arrange- ment of parts than in any turtle thus far discovered—a condi- tion moreover that has a more distinct bearing on the meaning of the Dermochelan anatomy than any other thus far observed in fossil turtles. In my original description I stated that “The medial plates unite very imperfectly by means of loosely doubled interlock- ing sutures and overlapping digitations grading into freauent free spines {spine-like projections] posteriorly. These digita- tions are mostly long, thin and ribbon-like, and produce a junction quite different from the usual suture. In many cases there is an appearance such as would result if the digitations of the one plate had lain upon the surface of the adjoining plate when it was in a plastic condition and thus raised rounded ridging about their edges. The order of the digitations and their size is rather regular.” It was also explained that the carapace was very thin on the midline and that at a break expos- ing the section back of the sixth rib there were thin layerings. And it should now be added that, bearing in mind that in the mounted specimen the dorsal vertebree remain articulated as originally, [ am, perhaps, censurable for not having the cara- pace sawn through at the line say of the third, sixth and eighth dorsal centra. However this may be it was not done, and, awaiting further specimens, the type specimen in which all details are certainly present must yield as its only quota of new fact the superticial details. Indeed, were it not for the accidental fact that back of the ninth medial element two prepygal median elements are missing, and yet that there is continuity of the carapace, it would likely escape us that two layers of bone are present on the midline. At the point where these elements have become disarticulated one can see that the pleurals expand broadly beneath the median plates, but we cannot tell to what extent they replace or crowd the neurals, 116 G. R. Wieland—On Marine Turtles. which are evidently small posteriorly. Immediately back of the nuchal, however, there does not appear to be an underly- ing neural, and one may say with certainty that all the anterior neurals at least are very greatly reduced. It is, too, equally clear that these mere thin sheets of underlying bones that can be referred to neurals, so far as they were seen in fracture sections, have had their function taken over by the FIGURE 8.—Archelon ischyros, x 1/36. Ventral view of type. Compare legend of the preceding figure. Note that all the elements of the plastron here shown occupied their normal position as originally recovered. Only the doubtful position of the omitted epiplastra prevents final accuracy. Note also the great length of the plastron; it is nearly as long as the cara- pace. Observe the small size of the femoral notches. The rib pair passing beneath the hyo-hypoplastral suture is the fifth. outer dermal series, which is continuous from nuchal to pygal and thus corresponds to the neural keel of Dermochelys. On the nuchal itself no additional elements were observed, but, as just stated, one may suppose from the great reduction in thickness such may well have been present. Indeed, it is not impossible that the posterior end of the nuchal extended beneath the first of the median supra-neural elements, and 5 G. R. Wieland—On Marine Turtles. ly that as a consequence our restoration is thus some ten centi- meters too long. Summarizing then: there are to be seen on the midline _ apparently overlapping all the neurals and the proximal bor- ders of the lamine of the nine pairs of normal ribs which pass out to meet the marginals, a series of eleven thin supra- neural elements simulating in size and outline a neural series. These supra-neurals form a distinct median keel and are of distinctly quadrangular outline all the way back to the eighth and ninth, which are short on the median line, but nearly as broad as the others. The digitate character of the sutures between the successive members, but more particularly of the pleural overlap, has already been commented upon. All the outlines are quite exactly shown in my original figure (refer- ence 6, Plate VI). A dominant feature of the midline is a nar- row median groove which extends from the second to the seventh member inclusive and is most pronounced in the sec- ond and fifth. In the mid-region of each neural enumerated the groove is somewhat widened and deepened, sending out a radially ranged series of nutrition furrows or striations which form a dominant sculpturing of the mid-region of the cara- pace. Some further horny or even ossitied elements may have occupied the mid-region of these shields. The aspect of the neural keel is thus seen to be different from that of any other turtle. The supra-neurals of Avchelon, be it noted, vary distinctly from those of Zowxochelys in which the series is not contin- uous and corresponds to a normal series of vertebral horn- shields. | In Archelon, however, a leathery hide must have been pres- ent, witha system of keels of the usual number, as denoted by dermogene ossifications rather than hornshields; these will be treated more fully later on. An ossicle like the supra- neurals of Zoxochelys was found by Hay accompanying Protostega advena, but its derivation was left in doubt. The pleural investment of the 72bs occupies only the proxi- mal fifth of their length. The free ends of the ribs are thus the dominating feature of the carapace. They are very heavy, in compensation for the light to almost paste-board thickness of the carapacial shield. The first rib is small and more or less ~ euryed and flattened. As in Protostega, it passed well to the front beyond the expansion of the first pleural, and may have supported either the thin posterior nuchal ala or possibly some osteodermal element. It is here necessary to note that the type specimen remained packed, partly in the matrix, from 1898 until 1906. Owing primarily, however, to a luckless defect in my field notes, Am. Jour. eae oe Vou. X XVII, No. 158.—Frsrvuary, 1909. 118 G. R. Wieland—On Marine Turtles. which rendered a lapse of judgment easy, it was thought for a time that the crushed coracoid of the specimen collected i 1902 was a heavy first rib. Asa result of this misconception, together with the uncer- tainty regarding the carapace that had long existed in the mind of every student of the Testudinata, I published the Fig. 9. FiGurRE 9.—Archelonischyros, x 1/36. Ventral view of the type with plastron removed. Compare legends of the two preceding figures. Recall that as originally collected the vertebral column from the fourth cervical on was found normally articulated and complete all the way to the smaller caudals, a few of which were missing. Observe that the coracoids pass all the way back to the ectopubes. Note in the hind paddle the large size of the tibiale and fibulare, and the pisiformoid development or functioning of the fifth carpal. erroneous figure of my paper of 1903." But why Dr. Hay has reproduced this in his volume,’ I fail to understand, as I spe- cifically declared the figure to be a mistaken one several years ago. I can only regret that the original figure of A. eschyros* was not used, and still more deplore the fact that the labor of preparation on the type was not sufficiently advanced to permit G. R. Wieland—On Marine Turtles. 119 the offer to Dr. Hay of a photograph of the mounted skeleton in time for use in his volume. The tenth ribs verify the original and excellent figure of the carapace in an important detail. In that figure, these ribs are both shown as distally restored to a length indicating support of the last marginal, were that element present. This restora- tion is correct, the right tenth rib having since been found complete, so that the length of the entire series is now abso- lutely known; and it should here be emphasized that while some of the ribs had disintegrated on one side or the other of the carapace, there is not a pair in the succession, from the first to the tenth inclusive, that lacks either a right or a left member complete to the tip. This functional development of the tenth rib is unique in the Thecophora. It denotes either a more primitive condition or a restrengthening of this element in compensation for a carapacial shield not only in process of reduction, but probably also of replacement by an external dermal series corresponding to the usual Testudinate keels or lines of longitudinal develop- ment. The Marginals.—The marginal series of A. eschyros, type, is considerably restored in the figures given (Plates II-IV), but not hypothetically so. There are present in sufficiently good condition for the determination of all the main features, margin- als referred to ribs extending all the way from the second to the eighth or ninth rib. Further, the fine third marginal is present (cf. figure 5), which in Protostega (Archelon) Marshir is suturally united with the fourth to sixth, the latter species having marginals of quite the same form as in A. ¢schyros, type. In the additional specimen of A. éschyros obtained in 1902, the seventh (?) marginal is also present, while the first to fourth are positively known in Protostega Copei (cf. figure 2). Hence, remembering the functional tenth rib, it may be defi- nitely stated that each rib beginning with the second bore a marginal and that the pygal marginal, the only member of the peripheral series not recovered in any of the larger forms of the Protostegide (it is present in P. advena), was thin, short, and broad, and must have had the form shown in the restoration (Plate II). The noteworthy and strange feature of the marginals is the strong digitation of both the superior and inferior plates and also of the anterior elbow formed by the outer border of the third marginal. Were it not for the fact that in 7. Copez the junction with the second marginal is definitely shown, it would scarcely be suspected that the true articulation of the third marginal with the second in A. ischyros, type, takes place by means of its long spinelike extension, which projects upward 120 G. R. Wieland—On Marine Turtles. and forward; for even in that portion of the outer border next. to the humeral notch there are blunt spines. Did the spines of the marginals articulate with one or more carapacial and plastral rows of dermal ossifications, and thus afford the nearest approximation to the osteodermal mosaic of Dermochelys yet discovered by adding dermal ossification on all the keel lines, that is the neural keel, the pleural keel, the supra- marginal, and marginal keel? I believe such to S be the case, for at least two elements referable to a similar additional series corresponding to the supra-pleural keel of Dermochelys have been recovered: || NO ice am strange that more have not been obtained. A fine shark’s tooth per- taining to a scavenger ies related to Lam- Figure 10.—Archelonischyros x4. A-large Se ae i as aan ce dermal ossicle found in connection with the 7% Was found with the - plastron of the original type, but possibly type, and clearly indi- dorsal. O, the outer view ; S, sectional view cates that all dermal por- showing the extreme thinness of the element. ,: . Note that the asymmetry of this element and tions loosely affixed to its dactylate border indicate not only connec- other elements of the tion with other dermal elements, but the e@ arapace or plastron probability of the presence of entire series of jyst have been pecu- such elements. 5 3 Eee larly lable to disassocia- tion. In what other than a supra-marginal or intra-marginal position is it possible to place the thin and distinctly asym- metrical element shown in figure 10? It represents an integral part either of the carapace or of the plastron. Further, the likewise unique element shown in connection with the marginal in figure 11 can not be interpreted as in other than a natural position. From the fact that it is digitate all around and slightly asymmetrical, it may be inferred that a series of such elements lay inside of, and articulated with, the superior borders of the marginals, alternating quite regularly with them in about a double number, and that beyond this space a second much thinner supra-marginal series was present. The space between the latter and the midline of the cara- pace, where, as has been already seen, the presence of a median row of supra-neural or in part osteodermal elements is demon- strated, may or may not have been continuously occupied by ossifications. In any event, there are the seven dorsal keels, as in Dermochelys. On the plastral side, direct evidence of Fie. 10. G. R. Wieland—On Marine Turtles. 121 dermal elements is lacking, although an agreement with the five plastral keels of the leatherback may be conjectured. The Plastron (figure 8).—The nearly perfect plastron of the type has suffered somewhat during collection, by its removal from an exceedingly hard marl matrix into which the numer- ous and often interlocking spines of the mid-plastral region penetrated. Nevertheless, as finally mounted, the plastron may be said to be in splendid condition. All the central Fie. 11. FicureE 11.—Archelon ischyros. Left eighth or ninth marginal as found in conjunction with an additional element in a supra-marginal position. Shown 1 natural size. If the anomalous element is not a supra-marginal it must be referred to the supra-neural series just anterior to the pygal. A slight asymmetry does not prevent, although it makes such a position less probable. It is easier to consider this element as having been found in a natural position, and as perforce thus accounting for the supra-marginal keel of the carapace of Dermochelys. portions of the large plates are present, with most of the spines, so that neither their size, form, length, or number, is ever in doubt. More important still, all the elements are but little crushed and, save the epiplastra, are present in their normally articulated position, just as they were figured in 1898." In 122 G. R. Wieland—On Marine Turtles. commenting on this figure, Dr. Hay states that a length of. 2100 millimeters is thus indicated for the plastron, making it larger than the carapace, which he considers impossible. Neglecting my measurement of the plastron, which was given as 2000+ millimeters, as well as the fact that the entoplastron is very plainly shown a little anterior to its true position, he also fails to note that the exact length of the carapace with the nuchal in position had not been determined by anyone. His first premise is therefore unfounded and his conclusion a pure assumption. : The important point, however, is that in the restoration, where the length of both carapace and plastron is definitely determined, the two are found to be nearly equal. In the dorsal view, the plastron appears a little shorter than the cara-’ pace, while ‘in the ventral view, the enormous expanse of the plastron, greater by far than in ’ Protostega Coper and greater than in any other sea-turtle, entirely cuts out the carapace. Archelon ischyros was certainly a very singular marine form ; with its enormous size, huge plastron, and small femoral notch set far back, it had need of the great humerus, which by reason of form and musculature represents a powerful sea-type. The unique T-shaped entoplastron of the Protostegide has had an interesting history. First called a nuchal by Hay in a Kansas specimen, it was left for Wieland*® to determine con- clusively and figure both these elements in A. zchyros, although there was uncertainty whether epiplastra were present at all. For reasons that now appear trivial, being merely an imper- fectly indicated condition of overlap seen in the field, the excel- lent point of view developed in the paper just mentioned was abandoned for a time.” Meanwhile the specimen of 1902 was obtained and was found to inelude still another puzzling bone,—the element that must be regarded as an anomalous epiplastron ; and still later the fine type of Protosteya Copei, here described, was discovered by Sternberg and acquired for the Yale collections. Thus was I enabled to determine finally that the nuchal and entoplastron noted in the paper of 1898° were truly such. This correction appeared in the Annals of the Carnegie Museum of Pittsburg for 1906.” That scarcely one of the naturalists interested in the Pro- tostegidze escaped from wrong conclusions as to the nuchal and entoplastron, is after all not surprising. Both elements are of a form not before observed, this being especially true of the entoplastron, which except in P. potens Hay shows no indica- tion of any ordinary type of epiplastral superposition or junction. G. R. Wieland—On Marine Turtles. 123 The epiplastra are doubtless of the form shown in figure 12. Referring to my first description, however, Dr. Hay thinks that the element figured must be the right, not the left member; superposition would therefore not be of the out- turned Trionychoid type that I have supposed. Dr. Hay saw this element soon after it was collected, and is consequently in a position to judge; nevertheless I think he errs and that the explanation of his opposite opinion is the condition he has observed in the entoplastron of P. potens. Moreover, I am not sure that he has correctly determined the hyo- and hypo- plastra in that turtle, for the elements he figures as xiphiplastra veh Wey Figure 12.—Archelon ischyros. Left epiplastron, x +. Ectal view on the right below and ental view on the left. On the right above, the ante- rior, and on the left, the posterior edge views of the recovered portion are shown. (There is no doubt that the restoration of the thin dactylate end is fairly accurate both as to form and size.) This element was not present in the original type, having only been observed once in all the history of the Protostegide. I should certainly have called hyoplastra. In either case, however, P. potens, the type of which Dr. Hay was kind enough to show us, is a-quite different turtle from any of the foregoing, and the evidence it affords as to the form of the epiplastra is only negative and quite uncertain. It seems much better to accept the positive evidence at hand, which is to the effect that if the element figured is the true epiplastron, it projected beyond the anterior border of the entoplastron and was borne on it quite as in Trionychids. But rather than risk finality in error, it has not been given a place in the restored type of A. ischyros. 124 G. R. Wieland—On Marine Turtles. The Ayo- and hypoplastra exhibit no very unusual features, except a great number of peripheral spines. The curved or somewhat boomerang-shaped az~phiplastra are of course more primitive than are the long and straight forms common to the Cheloniide. That the plastral fontanelles appear to be of less area than is shown in figures of Protostega, is due more to the fact that the plastron under consideration is the best and most complete example known in the Protostegidee than to any marked vari- ance in proportions. The plastral resemblance in Protostega and Avrchelon is very striking, in view of other differences separating these genera. The Shoulder Girdle and Manus.—The marked feature of the huge shoulder girdle is the projection of the coracoid all the way back to the pubis, a feature also present in Protostega and common to the existing Hretmochelys. The most charac- teristic element in the shoulder girdle of Avchelon is the humerus because of its distinctly thalassic type. | The testimony as to the organization of the manus is reason- ably complete and aside from minor differences exhibits general agreement with that of Protostega. The centrale in the latter is, for instance, more distinctly angled. While all the carpal elements of either a right or a left flipper are present, only the principal bones of the carpus have been found in position or approximately so. It is only in the left flipper that bones from another specimen have been introduced, namely, carpale I, the intermedium, and the pisiform, which fortunately were found together in this supplementary specimen. The only element in doubt was the centrale, but this seems to have been of a rounder form than in Protostega. Of the metacarpals and phalanges, the majority are present and the proportions of the fingers are essentially those adopted in the restoration, although when a specimen is once found with these elements in place, as in the case of the Pittsburg Museum specimen, some slight modification of the present restoration may prove necessary. The important anatomical features of the front flipper then are: (a) Agreement with Protostega ;. (b) general agreement ‘with the Cheloniidee, the centrale exhibiting strong. contact with metacarpal I, instead of exclusion from contact with this element by junction of the intermedium and carpale I1; (c) the comparatively slight modification and elongation of the phalanges for pelagic life, as contrasted with the much modified thalassic humerus. Although the latter is thus mod- ified, it lacks much of the strength exhibited by the paratha- lassic Dermochelan humerus; for. while the radial crest has shifted toward the middle region of the shaft, it has failed to G. R. Wieland—On Marine Turtles. — 125 retain a strong pedestal affording a powerful and firm type of muscular insertion. Curiously enough, the earlier Niobrara Protostega was better provided in this respect, since its radial crest forms a distinct ala nearly as prominent as that seen in Dermochelys. This failure of Avchelon to develop or retain, as the case may be, a prominent crest with stronger type of radial musculature may indeed indicate a certain failure to progress in swimming power and in resultant ability to follow the southward retreat of the great central Pierre sea. Im fact, it was at just about this period of culmination in‘size of the Protostegidee that the Dermochelan line more successfully accomplished such a change, as shown by the Eocene Psephophorus, a turtle nearly approaching Archelon in size and having a strongly pronounced and very low-set radial crest. Itis on such grounds, as much as by the possible destruction of the eggs of the young by marine or even by newly evolved mammalian enemies, that sufh- cient cause is surmised for the extinction of these most gigantic of all marine Testudinates. The Pelvic Girdle and Pes (figure 9).—The very perfect and uncrushed pelvis of the type was accompanied by the left femur, tibia, fibula, tarsals, and nearly all the metatarsals. On the right side, the femur is also present, with the proximal two- thirds of both tibia and fibula, which end in obliquely bitten off but healed surfaces. Both the femur and those mutilated elements are lighter and several centimeters shorter than the corresponding bones of the left side. In short, the evidence is conclusive and unmistakable that this animal had its right flipper bitten off when still young, and that as a result of this injury the remaining portion of the flipper was more or less arrested in growth by disuse. Such accidents are now and then noted in fossils. The type of Dromocyon voraz shows a broken lower jaw, subsequently reknitted, which was doubtless received in some raid on the young of Paleosyops, while a large per- centage of existing marine turtles have had their flippers more or less mutilated by predaceous fishes and sharks. I need not remind those familiar with the Testudinate osteol- ogy that the tarsal region of the sea-turtles is decidedly more variable in its organization than is the carpal region. Owing to this cause and to the failure to identify the excellently con- served tarsals with those of the crushed elements of Protostega gigas, it has not proved possible to orient the tarsals except in the most provisional manner. ‘They are all free and heavy bones, and there is little doubt that all were present on the left side, however difficult and uncertain exact orientation may be. The metatarsals are more readily recognizable, the fifth be- ing much flattened and highly characteristic. Its distal half 126 G. R. Wieland—On Marine Turtles. is largest, not smallest as in Protostega gigas. In closing this brief. “description of the flippers of A. eschyros, type, it should be emphasized that while there is marked resemblance to Protostega, it is only the resemblance of members of the same family, and that the chief variation is in the humerus and the pes. [The other region of marked variation is on the neural line ; the crania do not differ greatly. | he more important measurements of Avrchelon ischyros, type, are as follows :— | Weight of humerus, exactly 75 pounds = 34 kilograms. | Length of cranium from beak to occipital condyle 60°°™ four distal cervicals (estimated)._...-. 35° ie four proximal cervicals (present) -- ---- 33° S ten dorsal centra measured on the ven- tral: face ti iis 28 Wace Se eee eee 125° - two sacral vertebrev2 2 22). wee eee 9°5 Hf eighteen caudal centra (estimated ; only a tew of the more distal members are absent ise as ee eee ge a eos ne Ona Total absolute length from beak to tip of tail, from measurements on ventral face of centra 329°5 (The corresponding total exterior measurement is not so accurately obtained, being slightly affected by pressure, but must have been 3:4" = 11 feet.) Length of first dorsal cecil Bic ch Ra ois BECOnd LS 5:5) 25S ear keel eens Eee ae 15 es ‘hurd eS ate ta dey ae Bape tas ames ps HOULtANe aimed Suber aera) TSC Ss 16°5 és muro ye gs Sete amr Gets ||. Vo ge Sixt) 6 BM lela aes cae AN a ae 14:5 oe seventh “ PUMA oes hon a les ss eighth ‘ Rae CURL a am I hyn 10° 66 ninth 6c 66 ath eS a i Ae ii 6¢ tenth 6¢ 66 RT Ry ete S's 6° Total length of ten dorsal centra.._---.--- 124°0 renew of first. sacral centrum) width, 3™™.. Type, No. 1208. Stinus brevi-cubitalis gen, et sp.n. Text figure 9. The cubitus of this genus is short as compared with other genera of the family, being scarcely vaulted and reaching but slightly beyond the middle of the wing. Only two inferior branches are given off. The median area is correspondingly well developed. M, in the type species vives off three infe- rior brauches which fill the apical border. M, issimple. The radial sector arises back of the division of the media, and is pumaple: : Length of wing, 124™; width,4™™. Type, No. 459. Lecopterum delicosum gen. et sp. n. This is a genus of small Probniside. The wing is slender and not so coriaceous as in other genera of the family. The veins in the apical part of the wing are thin and more or less wavy. M,issimple. M, is three branched, Cubitus divides early. Beyond this first division it has but two inferior branches and is but slightly vaulted. Length of front wing, partly estimated, 9™™; width, 3"™. Type, No. 824. 162 i. A. Sellards—Types of Permian Insects. Lemmatophoride, family new. The family Lemmatophoridz includes small insects with four membranous wings as long as the abdomen. The pro- notum is bordered by a membranous expansion. The mesa- and meta-thoracic segments are strong. The subcosta is simple, and terminates on the costal border near or beyond the middle line of the wing. Numerous oblique branches are — given off from the radius beyond the termination of the sub- eosta. The radial sector is simple to four branched. The media is weak and at the base lies very close to the radius ; media is two to four branched. The cubitus at the base has a strong upward curve toward the media, with which it is united by a few strong cross veins. Cu, is one to three branched. Cu,issimple. The anal area is marked off by a thin depressed line, and is traversed by one or two strong veins. Cross veins in the wing are comparatively strong although not numerous. The hind wings are broader and shorter than the front. The anal area of the hind wing is expanded and folded. Lemmatophora gen. n. This genus of small Lemmatophoridee has elongate mem- branous arched wings. The wing membrane is minutely sealy. Subcosta is not arched at the base and extends beyond the middle of the wing. Sector arises near the middle of the wing and is simple. M, is simple. M, is widely forked be- yond the middle of the wing, and is thin at its origin from M,. Cu, is vaulted near its origin, and is two to three branched ; Cn, is simple. Two to four cross veins unite R, with Rs. age. soy 23°82 10°37 5) NT Oe oes eae 36°80 14°46 6 MeO given ee 7:02 2°10 1 SILOM G fala bee eae 1-00 PO Rp ee eee 2°21 98°65 Smith regarded. the silica and alumina as impurities, the latter arising from the spinel that it had been impossible to separate ; this, with a little of the magnesia, he deducted in making out the oxygen ratio from which he derived the formula: 6MgO .1FeO. 2Ti0, . 3B,0,,. Method of Analysis.—The material used for the present analysis was obtained from the Brush collection and came from Amity, N. Y., where this mineral is found as a characteristic associate of the granite contacts of the region. The warwick- ite occurs in minute slender crystals showing the copper-red reflections of the cleavage surfaces which is so characteris- tic of the pure mineral. It is found in a coarsely crystalline white limestone, intimately associated with a greenish blue spinel, black spinel, magnetite, serpentine, chondrodite and occasional scales of graphite. The limestone rock containing the minute crystals of warwickite was crushed to small frag- ments and these small pieces, which contained some of the mineral, were carefully selected by means of a glass. This material was again crushed and prepared for treatment with heavy solutions. Potassium mercuric iodide solution, having when concentrated a specific gravity of 3°15, was first used to separate the greater part of the calcite and. serpentine. The Bradley— Composition of the Mineral Warwickite. 181 - final separation was made by means of barium mercuric lodide with a specific gravity of 3°55. Considerable difficulty was caused by the presence of a greenish blue glassy spinel which in the solution closely resembled the grains of warwickite, but by repeated treat- ment with the heavy solution the latter was obtained in a quite pure condition. The material was further purified by the action of an electromagnet which helped to remove some of the - remaining foreign material. Finally by means of a very power- ful glass the few remaining grains of the associated minerals were as far as possible removed. The final sample obtained amounted to a little over two grams and was quite uniform in character. The specific gravity, determined by means of the barium mercuric iodide solution and a Westphal balance, was found to be 3°342; this is practically the same as that given by Brush, viz.: 3°351 for small fragments. Owing to the limited amount of material available for analysis it was desirable to determine the main constituents, B,O,, TiO,, MgO and total iron in one portion. After repeated fusions of the mineral with sodium carbonate the resulting cake was soaked out and the liquid decanted through a filter, the residue being thoroughly boiled with 25° of sodium carbonate solution and transferred to the filter and finally washed with dilute sodium carbonate solution. The filtrate containing the boron was transferred to a distilling bulb and the determination of boron made by distilling with methyl alcohol, the distillate being collected in ammonium hydroxide and finally evaporated over calcium oxide. The residue left in the bulb after distillation contained a trace of titanium which was recovered and added to the main solution previous to the precipitation of the titanium. The residue from the sodium carbonate fusion was brought into solution by prolonged fusion with acid potassium sulphate, and the resulting cake dissolved in cold water to which had been added strong SO, water. The solution was then largely diluted and rather strongly acidified with acetic acid; the titanium precipitation being made in the presence of sodium acetate and brought about by boiling the solution from three to five minutes, strong SO, water being added before the boil- ing point was reached. The precipitate was then filtered and washed with dilute acetic acid and finally weighed as TiO,,. -Some of the details of the above briefly outlined method are those recommended by Warren.* The filtrate from the precipitation of titanium was concen- trated and a very small precipitate was collected and added to * This Journal (4), xxv, 23, 1908. Am. Jour. Sci.—Fourtn Series, Vou. XXVII, No. 158.—Frpruary, 1909. 18 182 Bradley—-Composition of the Mineral Warwickite. the main precipitate before igniting. A trace of iron was also precipitated at this point, and this together with a mere trace retained by the main titanium precipitate was recovered by fusing the TiO, with acid potassium sulphate and a volumetrie determination for iron was made in the usual way with KMnO,. The filtrate from the titanium precipitation con- taining the iron in the ferrous state was treated with nitric acid to oxidize the iron, and hydrochloric acid added to form enough ammonium chloride to keep the magnesium in solution, when ammonium hydroxide was added to precipitate the iron, etc. Double precipitations of the hydroxides were made and the weight of the mixed oxides obtained. The oxides were then fused with acid potassium sulphate, and the total iron determined as usual by titration with KMnO,. Traces of titanium retained by the precipitate of ferric hydroxide were determined where present by the colorimetric method and corrections for both iron and titanium were made. ‘The amount of the alumina present was as usual arrived at by difference. The filtrate from the ammonium hydroxide pre- cipitation served for the determination of magnesium, which was precipitated as ammonium magnesium phosphate. This was then dissolved, reprecipitated ‘and filtered on a Gooch erucible and finally weighed as magnesium pyrophosphate. The determination of ferrous iron was made by dissolving the mineral in a mixture of hydrofluoric and sulphuric acids, and finally titrating with KMnO,, the modifications of Pratt* being used throughout the above operation. The results of the analysis follow :— I II Average Ratios BiOe re oe ey 21°36 21-29 "304 "304 MiOe 2 25206 24°66 24°86 310 eee SIOet) os ee Nl lp 1°32 1:39 0228 MrO> 2 85e4 36°01 Siem ‘84 eee MéOy so. 22 28k 9:20 9°15 127 pa We OL Aen 4°76 4°76 0297 AOR S295 2°87 2°91 0284 99°96 100°18 10007 The amounts of sesquioxides found are comparatively small and the ratios obtained from them have no rational relation to those obtained from the percentages of the other constituents. Disregarding the Fe,O, and A1,O, for the present, it will be » seen that the other constituents yield, 50... Ti0.2(Meg, Ke)O= 11-0042 2325. * This Journal (3), xlviii, 149, 1894. Bradley— Composition of the Mineral Warwickite. 183 This would point to B,O, . TiO, . 3(Mg, Fe)O as the formula for the mineral. Since, however, a glassy green spinel is so intimately associated with the warwickite and its separation from it, both on account of its closely similar specitic gravity, and because under the microscope it assumes an almost metallic appearance, it is thought reasonable to assign the 2°91 per cent of Al,O, found to its presence in the material analyzed. This assumption would necessitate the subtraction of an equivalent amount of MgO as required by the formula MgO. A],O,. Qualitative and quantitative tests on this spinel have proven it to correspond essentially to the variety known as chlorospinel, in which a little of the Al,O, is replaced by Fe,O,. In this particular spinel there was found 8°92 per cent of Fe,O,, and corrections for this isomorphous Fe,O, introduced into the -warwickite analysis by means of this spinel have been accord- ingly made. The presence of magnetite associated with the warwickite was proven by testing the impure material by the ordinary magnet. If, as is possible, it was intimately mingled with the warwickite it would be difficult to entirely separate it, as the warwickite itself is attracted easily by the electro-magnet. It seems reasonable therefore to assume that the greater part of the Fe,O, found was contained in magnetite, and that an equivalent amount of FeO to correspond to FeO . Fe,O, should be deducted from the analysis. Treating the analysis in this way we have the following results: Calculated Average Spinel Magnetite IIL to 100 Ratio B,O, 21°29 22 eo Sue ew OAL! mk TiO, 24°86 24°86 27°87 — °347 1090 SiO, 1°39 ° 1°39 Oem O25 MgO 35°71 —— 26 34°48 38°63 =*957 3-134 FeO 9°15 aloe) 7°20 SO ealel 2 t Fe,O, 4°76 — 42 —4°34 Al,O, 2°91 —2-9 1 100°07 89°19 100°00 The ratios from the corrected analysis yield B,O, . TiO, . 3( Mg, Fe)O as before, but with sharper agreement between the theoretical and derived numbers. The formula for warwickite can then be written, (Mg, Fe). TiB,O, which could be developed into a symmetrical structural for- mula as follows :— 184. Bradley— Composition of the Mineral Warwickite. The theoretical composition corresponding to this formula would be BO)? 25 9725-84 TiOs y= 20 54 3MgO = 44-65 100-00 In conelusion, the author here wishes to thank Professor W. E. Ford for his kind advice and assistance. Mineralogical Laboratory of the Sheffield Scientific School of Yale University, New Haven, Conn., June, 1908. Chemistry and Physics. 185 SCIENTIFIC INTELLIGENCE. I. CHEmistRyY AND Puysics. 1. The Question of Change in Total Weight of Chemically Reacting Substances.—H. Lanpour has devoted many years of the most painstaking work in investigating the weights of sub- stances in closed glass vessels before and after they were mixed to produce chemical reactions. In 1893 he published his first paper on the subject, in which he described work with reactions between silver sulphate and ferrous sulphate, iodic acid and hydriodic acid, iodine and sodium sulphite, and chloral hydrate and alkali. As a result of these researches he was unable to establish with certainty any change in the total weight, but it appeared that the separation of silver and of iodine were accom- panied by a slight loss in weight, so that the work was continued. In 1896 results were described, obtained with a balance of great precision, and with the use of much care, in which it was found that a loss was indicated, where silver or iodine were set free, in 42 out of 54 separate experiments. The changes in weight resulting from the use of 60 to 120 g. of reacting mass varied usually between ‘003 and -050 mg., and were often less than the estimated maximum error of ‘(03 mg. At this time it appeared to Landolt that these losses in weight, although small, were real, and he suggested the view, which was supported by the doctrine of the decomposition of radio-active atoms, that the violent shock which the atoms receive in chemical reactions might possibly cause the splitting off of minute particles of matter in the case of elements not belonging to the radio-active class, and that these might possess the property of penetrating the walls of glass ves- sels. Landolt has now published the results of additional, very elaborate, work on the same subject. He has explained fully the cause of former losses in weight in the fact that glass vessels which have been slightly heated by the chemical reaction within often do not return to their proper weight until after the lapse of a week or more, and he reaches the conclusion that in all of the 15 chemical reactions studied by him, no change in the total weight of the reacting substances has been established. This conclusion is of much importance in deciding the question, whether or not the atomic weights are of constant magnitude, for there appears to be no doubt that the force of gravity acts upon an atom to the same extent in any state of combination.— Zeitschr. physikal. Chem., \xiv, 581. ED, 1.) We 2. The Volume of Radium Emanation.—Professor RutTHEr- FORD has recently made some measurements of the volume of the gaseous emanation produced by radium. For this work the Royal Academy of Science in Vienna put at his disposal a prepa- ration containing about 250 mg. of pure radium. Much difti- 186 Scientific Intelligence. culty was encountered in purifying the gas, and the results varied to a considerable extent. The following table gives examples of the amounts of emanation in equilibrium with 1 g, of radium : At the beginning At the end of the experiment of the experiment 1°32°¢ mm 0°80° mm OFsOr* Moe O07" s 066) “ T:O0dae" 0°58 These results, considering the difficulties encountered, agree fairly well with the volume, 0°57°™™, which Rutherford has eal- culated theoretically, and the lowest result is only one-ninth of the volume, 7°:07°™™, found by Ramsay and Cameron some time ago. The gas underwent remarkable changes in volume after it was collected. In some instances it contracted to less than half its volume in the course of several hours, and then showed little change in the course of a week. In other cases an increase in volume was shown to double that of the original gas, and then a slow contraction followed. :These changes in volume, in many cases, bear no relation to the changes in volume of the emanation itself, for the true volume of the emanation was often only 20 per cent of the total gas volume. The author finds no satisfac- tory explanation: for these remarkable changes in volume.-— Monatshefte, xxix, 995. Hy Eee We 3. A New Method for Separating Tungstic and Silicie Oxides— Derracgz treats the mixed acids in a boat at a red heat with a current of hydrogen until the tungsten is completely reduced to a lower oxide or to the metal. Then the boat is heated in a tube, so arranged as to collect the volatile products, in a current of perfectly dry chlorine gas. If air is absent the whole of the tungsten is volatilized as hexachloride and oxychloride. The volatile products are collected by means of ammonliacal water and the tungsten is determined by one of the usual methods. The silica in the boat is weighed after heating it in hydrogen again to make sure, by the absence of any blackening, that the separation is complete. — Bulletin, TV, iii, 892. H, L. W. 4, A Silicide of Uranium. ” Duracaz has prepared the com- pound 8i,U by the aluminothermic method, using finely divided aluminium, flowers of sulphur, silica, and uranium oxide in proper proportions. The silicide forms a brilliant crystalline powder with metallic luster. It is interesting to notice that the author has prepared in the same way analogous silicides of molybdenum and tungsten, Si,Mo and Si, W, and that these silicides all corre- spond in type to the silicides of the iron group of metals having the general formula Si,M.— Comptes Rendus, cxlvii, 1050. H, L. W. 5. A New Periodic Function of the Atomic Weight.—ViKkToR Poscut takes the percentage composition of the earth’s crust as Chemistry and Physics. 187 calculated by F. W. Clarke, and by using these percentages as ordinates and the corresponding atomic weights as abscissas, shows that there is evidence of periodicity in the abundance of the elements. The curve which is carried only as far as nickel shows four maxima at oxygen, silicon, calcium and iron, and is regular enough to be very suggestive and interesting.—Zeitschr. physikal. Chem., \xiv, 707. H. L. W. 6. Velocity of Réntgen Rays; also their Influence on the Brush Discharge.—Ericu Marx has previously measured the velocity of these rays (Ann. der Phys., xx, p. 677, 1906) by a null method, and in order to justify his use of the method he employed follows with another paper which is devoted to the theory of the method. He discusses various phenomena of the rays which come into prominence in his method, and naturally treats also of ionization.—Ann. der Physik, No. 1, 1909, pp. 37- 56, 153-174. Jena 7. Radiation of Uranium X.—Uranium X was obtained by the Moore-Schlundt and Becquerel method. HEtNricu WiLLy SCHMIDT gives with many details the results of his investigation of the radiation of this substance. (1) The hard B-rays gave V=2 76102 em. secre e /m=0°67'10" E.M.E. (2) The soft rays are absorbed by aluminium according to an exponential law, and are deviated in a magnetic field in the manner of negative particles. (3) The curves of absorption, in different substances, varies much with the distribution of the radiation. (4) An under limit is given for the absolute value of the reflection of the B-rays for very thick plates. The absolute value of the reflected radiation is greater for the hard B-rays than for the soft rays.—Physikal. Zeitschrift, Jan. 1, 1909, pp. 6-16. : Vo dle 8. Infiuence of Self Induction on Spark Spectra.—G. BERNDT contends that the criticisms of Néculcéa and Hemsalech on his investigation of the influence of self induction on spark spectra (Diss. Halle, 1901) do not consider the factor of time of exposure of the photographic plate, for the introduction of self induction greatly weakens the intensity of the spark.— Physikal. Zeitschrift, Jan. 1, 1909, pp. 28-29. Jeers 9. Lonization of Gases, by Spark and Arc.—lIt is known that gases subjected to high temperatures in the neighborhood of electric sparks or the electric arc preserve their increased con- ductibility much longer than gases subjected to ultra-violet light, X-rays, or a- and B-rays. Hetnrica Ravscn, in a preliminary paper, investigates this property with a number of gases, among which were ordinary lighting gas, acetylene, hydrogen, carbu- retted hydrogen. He found a very long persistence of conducti- bility in lighting gas and acetylene.— Physikal. Zeitschrift, Oct. 25, 1908. Te 188 Scventific Intelligence. 10. Investigations in Radiation.—The recently issued number of the Bulletin of the Bureau of Standards (vol. v, No. 2) con- tains two articles on radiation to which attention should be called here. The first, by W. W. Cosientz, gives the result of experi- ments on the selective radiation from various solids. This is practically an examination of the emission spectra of electrical insulators, or transparent media, as they are called; a line in which, thus far, almost no work has been done. ‘The substances used were either in the form of solid rods, made in an oxy-hydro- gen flame, or of thick layers of the substance spread as a paste upon the heater of a Nernst lamp. The rods were heated by an electric current from the secondary of a 2000-volt 300-watt trans- former. The substances examined included a series of oxides, as those of zirconium, cerium, thorium, uranium, ete. ; also the minerals oligoclase, albite, orthoclase, beryl, rutile, apatite, cal- cite. All of these showed prominent emission bands at certain points; thus the oxides have a characteristic band at 2°8 to 3 and a second group of bands at 4°5 to 54, which may be due to the common element oxygen. The silicates have also a sharp emission band at 2°94 characteristic of SiO,. In the case of oligo- clase it is noted that the general emission, in distinction from the bands of selective emission, is less intense than in the other silicates studied. Further, the isochromatics of oligoclase are peculiar in that for it the emissivity is proportional to the energy consumed. A second article, by P. G. Nurrine, is an important discus- sion of the luminous equivalent of radiation, from the standpoint of both objective and subjective light and with especial reference to the establishment of a more precise relation between hght and its radiation, by which it can be alone measured. Il. Grotoey. 1. United States Geological Survey, Twenty-ninth Annual Report, 1907-1908, of the Director, GrorcE Otis SuitH. Pp. v, 99, with two plates.—This report contains a statement of the work done by the various divisions of the Survey during the fis- cal year ending June 30, 1908. The freedom from political influence, the efficiency, and the high scientific esprit de corps which have marked the Geological Survey since its origin have caused it to be intrusted with various added branches of work which after a period of development have been organized as sepa- rate bureaus, This is the history of the Forest Service and the Reclamation Service. The technologic branch has had a more recent inception and the question is now under consideration by Congress as to the advisability of its development into a separate bureau of mining technology. Such a bureau would supplement, along purely technologic lines, the geologic work of the Survey, and the two bureaus could codperate in investigations carried on Geology. 189 in behalf of the mining industry. A new branch of the Survey’s activity which has taken form during the past year is the classifi- cation of Government coal lands, 22,700 square miles being classified and valued. This work is a result of the movement for conservation of National resources; a movement which in turn has been able to take intelligent form, as well as popularity, largely as a result of the more purely scientific labors of the Sur- vey since its organization. The work of the Survey is thus seen to fall into two main divisions, work of a broad scope along fundamental lines, whose great value and utility may only become widely evident after the passage of decades, and work of immediate utility to meet the demands of the people and of Congress. The Survey is to be congratulated on having per- sistently followed work of both divisions. During the year the geologic branch published 9 geologic folios, 1 monograph, 2 professional papers, 18 bulletins and the annual volume on Mineral Resources. Mention of the important results cannot here be made. The topographic branch mapped 25,658 square miles, making the total area surveyed to date in the United States 1,051,126 square miles, or about 35 per cent. In Alaska 6,626 square miles were mapped, mostly on the scale of 1:250,000. Important work by the water-resources branch was done in the lines of stream-flow and ground-water investiga- tions, and investigations regarding the quality and pollutions of waters. The entire appropriation for the Survey was $1,445,020, of which $300,000 was expended for topographic surveys and $200,000 for geologic surveys. J. B. 2. Geological Survey of New Jersey: Henry B. Kummet, State Geologist, Franklin Furnace Folio.—There has recently been issued by the Geological Survey of New Jersey in coéperation with the United States Geological Survey, a geologic folio of the Franklin Furnace region in Sussex County. This locality is one of the richest mineral regions in the world, alike important economically for its enormous zinc deposits at Mine Hill and Sterling Hill, and no less scientifically for the number and variety of its mineral species. In addition to the zine minerals, over ninety well defined species are known from this locality, and eleven of these have not been found elsewhere. The region contains also extremely valuable deposits of white crystalline limestone and magnetic iron-ores. In the descriptive text of this folio, the geography, geology and geologic history of this region are fully described. Complete information is given regarding the mineral deposits, and maps and cross sections show the location and shape of the valuable ore bodies. ‘he folio may be obtained from the State Geologist, Trenton, N. J., price 25 cents, postage 15. cents additional. 3. A Sketch of the Geography and Geology of the Himalaya Mountains and Tibet ; by Colonel 8S. G. Burrarp, R.E., F.RS., Superintendent, Trigonometrical Surveys, and H. H. Haypesn, 190 Scientific Intelligence. B.A., F.G.S., Superintendent, Geological Survey of India. Pp. 230, pls. 37. Calcutta, 1907.—The three parts of this valuable monograph which have thus far been issued deal comprehen- sively with the geography of the Himalayas and to a less extent with the geography of all the great mountains of central Asia. Part I, on “The High Peaks of Asia” (46 pp., 8 pls.), by Col. Burrard, gives abundant statistics as to the height and distribu- tion of the 75 known peaks which exceed 24,000 feet in height. From an interesting chapter upon errors in observations of altitude it appears that even in the case of the most accurately measured peaks the figures usually given are liable to an error of from 100 to 300 feet. In part II, on “The Principal Mountain Ranges of Asia,” pp. 47-117, pls. 9-22, Col. Burrard describes in detail the various ranges, and shows how they originate in broad uplifts along axes which are generally parallel, but which often bifurcate or coalesce, and less frequently meet at right angles. A noteworthy chapter discusses observations with the plumb-line and pendulum which indicate that a concealed mass of excep- tionally heavy material lies beneath the plains of India far from, but parallel to, the Himalayas and their fast-growing subsidiary range, the Siwaliks. In part III, on “The Rivers of Himalaya and Tibet” (pp. 118-230, pls. 23-37), the main streams are classified according to both location and size. ‘They are described with the same clearness and care which are given to the description of the peaks and ranges. Attention is frequently called to the marked disagreement between divides and mountain ranges, It is the exception for a main divide to correspond with a main range. ‘The Indus river zigzags back and forth three times across the great Ladakh range. In the Hindu Kush region part of the streams flow northward across the main range ; while others cross it in the opposite direction flowing south ward. Numerous other evidences indicate the young stage of the mountains and plateaus and the lack of adjustment of drainage to geologic structure. Chapters on glaciers and on recent desicca- tion as indicated by Tibetan lakes, complete the discussion of drainage. The monograph as a whole is not only written in a very clear and interesting style, but is most accurate in detail, and most care- fully arranged to facilitate reference. Theoretical discussions are not avoided, but they play a minor part and are clearly distinguished from accepted facts and conclusions. A valuable feature of the monograph is its clear statement, not only of our knowledge but of the limits of our knowledge of the great mountains of Asia. E. H. 4. The Gases in Rocks; by KR. T. Cuamprriin. Carnegie Institution, Washington, 1908, 8°, 80 pp.—This paper embodies the results arrived at by a critical study of the gases evolved by heating 112 specimens of rocks in a vacuum. ‘The list includes all of the more important kinds of intrusive igneous rocks, lavas, stratified and metamorphic rocks and a few minerals. The Botany and Zoology. 191 methods appear to have been well selected and carefully carried out. The results show that carbon dioxide and hydrogen are in general the gases most largely evolved, while minute amounts of carbon monoxide, hydrogen sulphide, methane and nitrogen are apt to accompany them. The author recognizes, of course, that a considerable, or even the larger, part of these gases were not contained in the rocks as such but were evolved from carbonates, sulphides and hydrates, and he discusses their possible origin from these substances and from others not known to be present in rocks, such as carbides and nitrides, but which might conceiv- ably be present in the igneous ones. Rocks, however, are such com- plicated bodies and the possible reactions and interactions which may take place at high temperatures so many and so involved when a large number of factors .are concerned, as brought about by the possible presence of sulphides, metallic oxides of a lower state of oxidation, carbon and even metallic particles such as copper and iron, that it appears possible that all of these gases except the nitrogen may have been produced from original solids, sulphides, carbonates and hydrates. While some of the gases such as CO, and water vapor are undoubtedly contained in rocks as such, it thus becomes a matter of doubt as to how much of the gases evolved are to be considered original and how much ascribed to secondary alteration of the original minerals. In this connection the reviewer regrets that the work was not accom- panied by a microscopical examination in thin section of the actual specimens studied, since this would have thrown much light upon the presence or absence of such secondary products. In conclusion the author discusses the bearing of the results obtained upon general problems of geology and with reference to the early condition and origin of the earth. While no essen- tiaily new or startling facts have been brought to light by this undertaking, it is none the less a very useful piece of work of a laborious nature which has been carefully carried out and which will prove of service in the future in aiding to solve problems of chemical geology. Many investigations of just this character are needed before speculation upon the early history and character of the earth’s crust can rest upon secure founda- tions. Bowen, III. Borany anp Zoo.oey. 1. The Forest Flora of New South Wales; by J. H. Maipen, Government Botanist, and Director of the Botanic Garden, Sydney.—This useful treatise has now begun its fourth volume. ‘The training of the author for this important contribu- tion to science has been of a peculiar character. After having familiarized himself with the most approved Museum methods in England, he took charge of the great economic Museum in Sydney, where, under many discouragements, he built up a vast 192 Scientific Intelligence. establishment, which has proved of immense use to the Colony and its sister Colonies. Early in this work of organization he prepared a useful treatise on the Useful Plants of Australia, which embodied a whole treasury of technological information. During this term of service he was in constant correspondence with all parts of Australasia, accumulating materials from all quarters. After the death of Baron von Mueller, Mr. Maiden became the Government Botanist, and he was appointed also | Director of the Botanic Garden in Sydney, a post which the Baron did not occupy in his last years. Kquipped with an unusual amount of technological information, Mr. Maiden has undertaken to make his Flora, as far as possible, practical. In this he has succeeded admirably, so that the forest flora is available as a hand-book even to those who are far removed from the southern hemisphere. The illustrations and text are of a high order throughout. G. L. G. 2. Jaarboek van het Department van Langbouw in Nieder- landsch-Indie, 1907.—The report on the Agriculture of the Dutch East Indies has just come to hand. It contains a full account of the efficient stations in the districts, in which the more important technical plants and their products are studied with reference to improvement. The Garden at Buitenzorg and the experiment stations are well illustrated and described. It is no wonder that the Dutch have been able to maintain their place in the fierce competition for supremacy in the export of tropical products. The authorities have spared no expense or labor in applying the most modern methods of cultivation throughout Java and the out- lying islands. : G. L. G. 3. The Origin of Vertebrates ; by WattTER Hotsrook GaAs- KELL. ‘Pp.ix + 537. London and New York, 1908 (Longmans, Green & Co.).—This book forms an important contribution to the speculation as to which particular group of existing invertebrates, if any, has given rise to the vertebrate animals by a process of evolution. For twenty years the author has held the view that the nervous system of the vertebrate is in part a modification of the alimentary canal of some invertebrate ancestor. He believes that the great factor in evolution has been the growth of the central nervous system, and that with this factor it is possible to trace the evolution of the mammal from the reptile, thence back to the amphibian and the fish ; the latter arose from the arthropod, and this from the annelid. The vertebrate is therefore the natural evolution of a primitive crustacean ancestor. This view, of which the author has been one of the leading exponents for many years, is thought to be sustained by a critical comparison of each organ system of the vertebrate with that of its supposed crustacean prototype. With all the possible evidence thus ably presented, it will be of interest to learn whether further enthusi- asm will be aroused for a theory which has thus far found few supporters. WwW. R. C. _— oe ee re ae a lla Botany and Zoology. 193 4. Ticks: a Monograph of the Ixodoidea ; by Grorce H. F. Norrati, Ceci, Warpurton, W. F. Cooprr, and L. E. Rosrnson. Part I, Argaside. Pp. x + 104, with a bibliography of 35 addi- tional pages. Cambridge, 1908 (University Press).—The discov- ery that ticks play a most important part in the transmission of certain diseases of man and domestic animals, has led to a renewed interest in this group of parasites. The present work will contain, when completed, a description of all known species of the group, with a discussion of their structure, life history, and economic importance. References are made to all the important literature on the subject, the bibliography being printed on one side of thin paper, so that the titles can be cut out, if desired, and gummed on index cards. The work is well illustrated by half- tone plates and numerous text figures. We i. 5. Animal Romances ; by GraHamM RensHaw. Pp. 206. London, 1908 (Sherratt & Hughes).—A series of vivid word pictures of animal scenes in various portions of the world. A Caucasian autumn scene with its background of mountain forest, ' into which the characteristic birds, mammals, and other animals are projected with kaleidoscopic effect, is followed by a glimpse of the Malay jungle at midnight ; while the latter picture grad- ually dissolves into the noon-day glitter, to be in turn lost in the dusk of evening; a continuous procession of living creatures passes before the eye, each one acting its part in the full seclu- sion of its native haunts. Other chapters reveal the life of the African wilderness, the Antarctic seas, the Andean mountains, the Australian bush, the Pacific coral reef and other regions of the globe. Most of these scenes apparently have been drawn directly from the personal impressions of the writer, and portray vividly and accurately the living creature in its natural activities and customary environment. The illustrations are all taken from photographs by the author. 7 W. R. C. 6. Hssays on Evolution, 1889-1907; by Epwarp Baanate Povutton. Pp. xlviii+ 479. Oxford, 1908 (Clarendon Press).— This volume consists mainly of ten essays on the subject of evolution, delivered as addresses on various occasions since the year 1889. ‘The text of the original essay has been altered _ whenever necessary to represent the views of the author at the present time, and the last and longest essay on “‘ The Place of Mimicry in a Scheme of Defensive Coloration” has been entirely rewritten and emphasis laid on the advance in the knowledge of the subject in recent years. The new discoveries supporting the doctrines of Mendelism and of Mutation are discussed in an introductory chapter, and with some of the expounders of these doctrines the author has little patience, because of their qyite unnecessary depreciation of other subjects and other workers. On the whole, the book forms a most interesting and important exposition of some of the most vital topics of Darwinian evolu- tion by a well known authority on the subject. W. RB. C. 194 Screntifie Intelligence. 7. Parasitology: a supplement to the Journal of Hygiene ; edited by Grorce H. I. Nuraur and A. E. SurpLrey.—A newly established journal devoted to the publication of original contri- butions on the biology of the animal parasites of man and animals. IV. MIScELLANEOUS SCIENTIFIC INTELLIGENCE. 1. A New Goniometer Lamp; by Frep. Evegense Wricut. (Communicated from the Geophysical Laboratory.)—The gonio- metric measurement of minute crystal faces requires a source of illumination of such intensity that for the past five years the | writer has employed an electric arc goniometer lamp (Proc. Amer. Philosophical Soc., xlii, 237-238, 1903) for the purpose. Certain Fig. 1. features of the are light, however, are not favorable for its con- stant use, and although, on occasion, it is the best light procura- ble, other sources of illumination have been found better adapted for general work.—The Nernst light is an excellent source, and were it not for the present unreliability of the filaments, would serve every purpose.—The acetylene light, however, has been found by experience to be the most serviceable, and the following goniometer lamp has been constructed for its use. This lamp is Miscellaneous Intelligence. 195 modeled in principle after the Welsbach goniometer lamp of Goldschmidt (Zeitschr. Kryst. xxili, 149-151, 1894), and consists essentially ofa tee with side outlet (fig. 1, A, 1°5-in. diameter) with iron pipe fittings, B and C, of proper length, together with a base plate, D. This device fits over the acetylene burner L, and can be removed at any time and the aeetylene burner used for other purposes. The mirror, F’, serves to reflect the hght from the burner to the verniers of the goniometer, and, like the Gold- schmidt lamp mirror, furnishes all ight requisite for goniometric work. By means of the brass shield plate at EK, the side outlet of A can be opened and closed at will, and with it the light from the burner to the mirror. The materials of which this lamp is made are all on the market and can be readily procured from any pipe-fitting establishment and assembled at moderate cost by a mechanic. ‘The acetylene burner is of the usual one-half foot type and the generator No. 102 of the firm of J. B. Colt, New York. 2. A Containing Device for Salts Used as Sources for Mono- chromatic Light ; by FrRep. KucENE Wricut. (Communicated from the Geophysical Laboratory.)—For many years sodium, . lithium and thallium compounds have been employed to produce fairly monochromatic light,—yellow, red and green respectively-— and a number of different devices for holding such salts in the Bunsen flame have been suggested which answer the purpose more or less satisfactorily. The following simple arrangement (fig. 1), which is apparently novel, has been found useful and effective by the writer in this connection and merits a brief word of description. The salt is placed in a small thin-walled platinum crucible about 1°5 to 2° long and 10™™ in diameter (P of fig. 1) ; a bundle of fine platinum wires (fig. 1, D, 4-5°™ in length serves as a wick and is held in proper place by pinching together one side of the platinum crucible, as indicated in the figure. The crucible is supported by a thick platinum wire L, which in turn is attached to the tube B of the Bunsen burner by the clamp A. The platinum crucible is purposely inclined at an angle as indi- cated in the figure, in order that its side may be reached by the flame and heated so hot that the salt it contains melts and is gradually fed into the flame by the wick of platinum wires. A single charge of sodium carbonate thus introduced has, been 196 Scientifie Intelligence. used for weeks at a time. By having on hand three such devices, one for sodium, the second for lithium and the third for thallium salt, the observer can at any instant change from the one to the other and proceed with his measurements for hours if necessary without further care for the flame. By this process of melting down the salts, the flow of fresh material is continuous and the flame is constant and remains practically unchanged for a long period of time. 3. Report of the Secretary of the Smithsonian Institution for the year ending June 30, 1908. Pp. 84. Washington, 1908.—The annual report of Dr. Charles D. Walcott, Secretary of the Smith- sonian Institution, has recently been issued. It gives the usual interesting account of the workings of the Institution in its varied functions, prominent among which are the National Museum, the Bureau of American Ethnology, the International Exchanges, the National Zoological Park, and the Astrophysical Observatory. The work of the Institution is now so well organized that it goes forward in a manner most satisfactory to all the interests involved. In regard to the new building for the National Museum, it is stated that the walls are completed and the construction of the roof well under way. ‘There remains, however, the fitting up to the interior, including some ten acres of floor space. ‘The most interesting part of the work of the Bureau of Ethnology has been the excavation and repair of the Casa Grandé ruins in Arizona, under the charge of Dr. Fewkes. Although the work has not been completed it has progressed far enough to present a typical ruin, given the general character of the ancient Pueblo remains of that region. This most interesting subject, and others related, are described in detail in an Appendix to the present Report, prepared by the Chief of the Bureau, W. H. Holmes. Other appendixes are given by the gentlemen in charge of the different departments, among which must be mentioned that by C. G. Abbot on the work of the Astrophysical Observatory. A number of special investigations are enumerated which are now being carried on by grants from the funds of the Institution. The Annual Report of the Board of Regents for the year end- ing June 30, 1907, has also been issued. This contains the Report of the Secretary, issued in advance about a year since (see vol. xxiv, p. 160). ‘There is also the usual Appendix, pp. 95-709, con- taining selected articles of general scientific interest on a wide range of topics. As most of these are not easily accessible in the original, their republication here should be of great pelt to the intelligent reading public. OBITUARY. GrorcE W. Hoven, Professor of Astronomy at Northwestern University and Director of the Dearborn Observatory, died at his home in Evanston on January 1 in his seventy-third year. — New Circulars. 84: Ejighth Mineral List: A descriptive list of new arrivals, rare and showy minerals. 85: Minerals for Sale by Weight: Price list of minerals for blowpipe and laboratory work. 86: Minerals and Rocks for Working Collections: List of common minerals and rocks for study specimens; prices from 1% cents up. Catalogue 26: Biological Supplies: New illustrated price list of material for dissection; study and display specimens; special dissections; models, etc. Svxth edition. Any or all of the above lists will be sent free on request. We aré constantly acquiring new material and publishing new lists. It pays to be on our mailing list. Ward’s Natural Seience Establishment 76-104 Cotrege AvE., Rocuester, N. Y. Warns Natura Science EstaBlisHMent A Supply-House for Scientific Material. Founded 1862. Incorporated 1890. DEPARTMENTS: - Geology, including Phenomenal and Physiographic. Mineralogy, including also Rocks, Meteorites, etc. Palaeontology. . Archaeology and Ethnology. Invertebrates, including Biology, Conchology, etc. - Zoology, including Osteology and Taxidermy. Human Anatomy, including Craniology, Odontology, etc. Models, Plaster Casts and Wall-Charts in all departments. Circulars in any department free on request; address Ward's Natural Science Establishment, 76-104 College Ave., Rochester, New York, U. S. A. CONTENTS. Page Art. VII —Revision of the Protostegide ; by G. R. WieLanp. (With Platessl-VyV). | 3 oe ee eee 101 VIII.—Submarine Eruptions of 1831 and 1891 near Pantel- *Jeria’; by“EhS. WASHINGTON: 2-0 o2ge ae ee i3l 1X.—Types of Permian Insects; by E. H. Szeruarps._-- ._- Weule X.—Iodometric Estimation of Vanadic Acid, Chromic Acid and Iron in the Presence of One Another ; by G. EpGar 174 XI.—Analysis and Chemical Composition of the Mineral Warwickite; by W. Mi Drapiny 2). 2 ee 179 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Question of Change in Total Weight of Chemically Reacting Substances, H. Lanpout: Volume of Radium Emanation, RUTHERFORD, 180.—New Method for Separating Tungstic and Silicic Oxides, Deracgz: Silicide of Uranium, Deracgz: New Periodic Fune- tion of the Atomic Weight, V. PoOscHi, 186.—Velocity of Rontgen Rays ; also their Influence on the Brush Discharge, HE. Marx: Radiation of Uranium X, H. W. Scumipr: Influence of Self Induction on Spark Spectra, G. Bernpt: Ionization of Gases by Spark and Are, H. Rauscn, 187.—Investigations in Radiation, W. W. Copientz and P. G. Nourrine, 188. Geology—Twenty-ninth Annual Report United States Geological Survey, G. O. SmitTH, 188.—Geological Survey of New Jersey, H. B. KuMMEL : Sketch of the Geography and Geolog gy of the Himalaya Mountains and Tibet, S. G. Burrarp and H.: H. Havypen, 189.—Gases in Rocks, R. i” CHAMBERLIN, 190. Botany and Zoology—Forest Flora of New South Wales, J. H. MAipEn, 191 —Jaarboek van het Department van Langbouw in Niederlandsch- Indie, 1907: Origin of Vertebrates, W. H. GasKELu, 192.—Ticks: a Monograph of the Ixodoidea, G. H. F. Nutratu, C. WaRBuRTON, W. F. Cooper, and L. H. Ropinson: Animal Romances, G. RENSHaw: Hssays on Evolution, EK. B. Povuuton, 198. —Parasitology, G. H. F. NuTALL and A. E. SHIPLEY, 194. Miscellaneous Scientific Intelligence— New Goniometer Lamp, F. E. WricuHt, 194.—Containing Device for Salts Used as Sources for Monochromatic Light, F. EH. Wricur, 195.—Report of the Secretary of the Smithsonian Institution for the year ending June 30, 1908, 196 Obituary—G. W. Hoven, 196. ei yr. Cyrus Adler, / ; a me SS z= Librarian U. S. Nat. Museum. © ii VOL. XXVII. MARCH, 1909. Established by BENJAMIN SILLIMAN in 1818. AMERICAN JOURNAL OF SCIENCE. Epiron: EDWARD S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, W. G. FARLOW anp WM. M. DAVIS, oF CamBrwpcz, Proressorss ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON anp H. E. GREGORY, or New Haven, Proressor GEORGE F. BARKER, or PHILADELPHIA, Proressor HENRY S. WILLIAMS, or ItuHaca, Proressor JOSEPH S. AMES, or Battimore, Me. J. S. DILLER, or WaAsuHINGTON. FOURTH SERIES No. 159—MAROCH, 1909. VOL. XXVII-[WHOLE NUMBER, CLXXVII] ae oak ff Syl! f NEW HAVEN, CONNECTIOUT.( Map 1909. st ae ~ ae THE TUTTLE, MOREHOUSE & TAYLOR O©O., PRINTERS, 123 TEMPLE STREET, Published monthly. Six dollars per year, in advance. $6.40 to countries in th Postal Union ; $6.25 to Canada. Remittances ‘should be made either by money sare. registered letters, or bank checks (preferably on New York banks). RARE CINNABARS FROM CHINA. We would call attention to these remarkable Cinnabars, some of wink still remain. They are beyond doubt the most beautiful and interesting crystals of Cinnabar ever discovered. They were described and illustrated : this Journal, Noy. ’08. The prices range from $5, $7.50, $10, $15, $18, 25, $35, and $50. NEW ARRIVALS. Kuclase, Capo do Lane, Brazil; Chalcocite, Conn.; Columbite, Conn.; Monazite, large loose xls. and in matrix, Conn.; Uraninite, crystal in matrix, Conn.; Benitoite, San Benito Co., Cal.; Neptunite, Cal.; Lievrite, Elba; Polybasite, Hungary and Mexico; Herderite, Poland, Maine; Cali- fornite, Tulare Co., Cal.; Cobaltite, loose crystals and in matrix, Cobalt, . Ont., and Sweden; Vivianite, large crystals, Colo.; Olivinite, Utah ; Sarto- rite, Canton Wallis; Jordanite, Binnenthal ; Crocoite, Siberia and Tasmania ; Cinnabar, Cal., Hung. and China; Gypsum, twin crystals, Thuringia ; Diamond in matrix, New Vaal River Mine, South Africa; Argentite, Mexico ; Freiberg, Saxony; Pyrargyrite, Saxony and Mexico; Pyromorphite, Ems, Germany, Phoenixville, Pa.; Tourmalines, beautiful sections from Brazil ; Brochantite, on Chrysocolla, Utah; Pink Beryl, small and large, Mesa Grande, Cal.; Kunzite, small and large, Pala, Cal.; Sphene, Binnenthal ; Titantite, Tilly Foster, N. Y.; Tetrahedrite, Utah and Hungary; Realgar, Hungary ; Opal, Caribou River, Queensland ; Torbenite, Eng.; Bismuth, native, Cobalt, Ont.; Emerald, loose and in matrix, Ural; Zircon erystals, loose, Ural; Green and Cinnamon Garnets, Minot, Maine; Vesuvianite, Poland, Maine, Italy.and Tyrol; Zeolites, beautiful specimens from Hrie Tunnel, Patterson, and Great Notch. NORWAY and SWEDISH MINERALS. Just secured a fine lot of exceedingly rare minerals; as they are now in the Custom House, and cannot be listed in time for this issue, kindly write for list of same. CUT GEMS. Garnets, green and red; Aquamarines; Zircons, all shades; Sapphires, all shades ; Star Sapphires and Star Rubies ; Chrysoberyl, Cats-eye ; Spinels, all shades ; Topaz, pink, blue, brownish and golden color; Pink Beryl; Sphene; Tourmaline, all shades; Amethyst, Siberia, royal purple Star Quartz; Peridote; Opal matrix, Mexico and Australia; Hyacinth; Tur- quoise, Mexico and Persia: Kunzite; Reconstructed Rubies and Sapphires ; Opal carvings; Antique Cameos and Mosaic, and other semi-precious stones. Let us know your wants, and we will send the specimens on approval to you. Write for our new circular to-day. A. H. PE TERE ds 81—83 Fulton Street, New York City. THE AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES.] o> Art. XII.—Recent Observations in Atmospheric Electric- toe. “yee. DikE, Iv is somewhat difficult to give a satisfactory résumé of recent work in Atmospheric Electricity which can claim to be complete and at the same time strictly up to date, since aside from the four or five centers from which emanate most of the contribu- tions to the advance of the subject, work is podmensly coming to light from unexpected sources. We have been in the habit of looking to Elster and Geitel, Gerdien, Ebert, and a few others in Germany, to the Caven- dish Laboratory in England, and to Rutherford and his fol- lowers at McGill University, Canada, for most of the work in Atmospheric Electricity, but of late other experimenters have begun to enter the field. Not very much has been done as yet in this country along these lines, and what has been done has been scattering and desultory for the most part, consisting of the work of an indi- vidual here and there. There has been no such extended and persistent study of the subject, and such careful experimenta- tion as has been going on in England and Germany for some years, and which has yielded so many important and interest- ing results. For this reason most of the work referred to will necessarily have been done in foreign laboratories. The field of research in Atmospheric Electricity is a broad one and pre- sents numerous complications of a most troublesome sort, which offer to the observer abundant opportunity for the exercise of his ingenuity. The earliest known and most thoroughly studied of all the phenomena included under the head of Atmospheric Electricity * Presented before the Philosophical Society of Washington, October 24, 1908. Am. Jour. Sci.—FourtH Series, Vou. X XVII, No. 159.—Marcnr, 1909. 14 198 Dike—Recent Observations in Atmospheric Electricity. is the potential gradient—the existence of an electric field about the earth, resulting in a difference of potential between the earth and any point in the air above it. The existence of such a potential is readily shown by the use of a suitable electro- scope or electrometer connected to a collector, such as a flame, a water dropper or a radio-active body. Potential gradients exceeding 100 volts/meter are ordinary, and during times of electrical disturbance, even with a clear sky, this may inerease to 1000 volts or more. The mean value at Kew, England, has for eight years exceeded 159 volts per meter, while on January 1, 1908, during a fog it exceeded 730 continuously for 84 hours. Its fluctuations are abrupt and of great range, sometimes passing suddenly from large positive to negative values. At Kew, at Potsdam, and at various other observatories, continuous records have been kept of this most erratic phenomenon by means of self-recording instruments for years, in an attempt to establish some relationship between it and other meteorological elements, but so far without very definite results, except for a possible connection with the barometrie¢ pressure ; and this relationship, according to Chree, seems to point to change of potential gradient as a cause, and change of pressure as a result. It would seem to be almost impossible to correlate such a phenome- non with local weather conditions except in so far as electri- cal storms are concerned, when it is considered that as a charged body we have the earth, whose electrical condition is depend- ent on conditions prevailing over its whole surface rather than on local phenomena. By recent observers the study of this element of the problem has been made subsidiary to other investigations in which it is involved as a factor, principally in the computation of the earth-air currents. An interesting series of investigations with a practical end in view has been made by Creighton of the General Electric Company bearing upon the subject of electrical storms with especial reference to lightning discharges and the operation of lightning arresters on transmission lines. Laboratory experi- ments were supplemented by observations at two power plants in Colorado where electric storms are of daily occurrence in summer. By means of a rotating film or a moving sensitive tape the duration of a discharge on a transmission line was measured by means of projecting the light from a spark gap connected with the line upon the film. D’.” We shall next consider what bearing formula (1) has on the question of minimum deviation. The well-known, general equations for refraction by prisms are sin 7,=”n sin @, 0 sin 7,=7 sin @, ang 0, =, cos 7, sin 8’, =n cos 7, sin f’, COS Z, sin B, =7N COs i, sin B’, eee n denotes the ratio of the absolute index of refraction of the material of the prism to the absolute index of the sur- rounding medium. In general, we shall assume n>1. By using the equations of the above list together with the relation cos B', cos 8’, =cos f’, cos B’,; which is a necessary condition that D’ shall be either a maxi- mum or minimum, when 2, is kept constant, we find 6’,= 8’ ,=+4a' and hence cos 27, sin 3(D’,+a’)=(+ ,4/n’—sin*é,) sin ja’. (2) D’, denotes the possible stationary value of D’. Equation (2) is equivalent to the usual formula “cos 7, sin $(D’,+a')=n cos @, sin 4a’,” since 7 sin 7,=sin 7, and 7,%47. It should be observed that, in obtaining equation (2), use has to be made of the relation ‘— PB’ + ’,—a’ and this shows that the various writers intend to employ the same definition of deviation as the one given above. d’D’ dp? ) If we actually test under the specified conditions, we 226 LH. S. Uhler—Deviation of Rays by Prisms. find that D’, isa true minimum, as would be expected from our knowledge of the existence of a minimum when 7,—0, that is, when the projection of the ray coincides with the ray itself and the latter les in a principal section. Hence, we can conclude from equation (1), since sines affect both D and D’, not only that D has a stationary value simultaneously with D’ but further that D attains a minimum value D, at the sume time that D’ acquires its minimum D’,. +/10?— sin7Z COS 7, >n. Hence equation (2) shows that when the deviation of the projection of a ray not in a principal section assumes a minimum value, this value is greater than the minimum of deviation for rays ina principal section. Now equation (1) gives D,< D’,, (4, = 0), and equation (2) implies D’, > A,, where A, represents the minimum deviation for principal sections. Consequently, on the face of it, nothing can be coneluded. about the relative sizes of D, and A,. For example, how do we know that the deficit of D, with respect to D’, may not be numerically greater than the excess of D’, over A, so as to make the minima of deviation for rays not in principal sec- tions less than the minimum of deviation for rays in principal planes? In other words, how can we logically deduce the usual and correct theorem that: “The deviation of a ray by a prism is least when the ray passes through the prism in a principal plane and when the angles of incidence and emerg- ence are equal” ?* The usual argument is to say that D’, exceeds A, in value, that the equation “cos 4D— cos 4D’cos 2,” shows D to be greater than D’, that D passes through a mmmemum value simultaneously with D’ and that therefore a fortvort D, > A,. This assumes that D has a minimum, whereas both the D and the D’ involved in the cosine formula pass through maxima simultaneously and the general theorem does not follow. Consequently we shall now outline the proof of a formula for D, as a function of a’, 7, and m in order to see explicitly what the properties of D, are. This formula may be obtained as follows: First, expand sin $(D’,+a’) of equation (2) in terms of sines and cosines of the angles $D’, and $a’. Next, reduce all cosines to sines, except cos $a’, and, after proper transposal of terms, square the members of the resulting equation. A quadratic in sin $D’, results and this equation is then solved for sin $D’,, care being taken to retain only the *R. S. Heath, Geometrical Optics, p. 32, 1887; or Czapski, Kayser, Winkelmann, etc. Again, since by hypothesis » exceeds unity, H. §. Uhler—Deviation of Rays by Prisms. 227 proper sign before the radical. In this manner we find, after substituting in formula (1), that sin $D,={[ + 4/(”’— sin’ z,) cos’ $a’]— [+ 4/(2*— sin*z,) cos’ ga’ —(n* —1)]} sin $a’ (3) Obviously, this equation could not have been obtained by substituting in “cos $D,= cos $D’, cos z,”, and hence, if formula (3) is correct, the cosine equation must be erroneous. Again, formula (3) leads to dD, sin 27, sin $a’ cos” ga’ ; + di, cos sD, ] i q 1 + /(n*—sin’ 7,) cos*$a'—(n?—1) — +.4/(n* —sin*7,)cos? 4a’ J (4) Since D, cannot exceed 7, and since the first fraction within the braces of equation (4) is larger than the second, it follows that D, decreases when 7, diminishes in absolute value. There- fore, the minima D, of D decrease as 2, approaches zero in magnitude until, when 7,0, D,=A,. Thus we have shown formally that, although D, is always less than D’,, D, is con- stantly greater than A,. The general theorem of minima quoted above from Heath is therefore established. Equation (3) is interesting because the second radical indi- cates limitations upon a’, z, and 7 in order that D, be real, that is, in order that a minimum of deviation may exist. For illustration, when a’ and nm are given Z, < sin” [+ 4/1—(n*—1) tan* 3a’), nr —2 2 whichin turn recuires cosa’ > Furthermore, combining . with equation (2) the condition that the second radical of formula (3) shall vanish, we find sin 3(D’,+a’)=1, so that D’, and a’ are then supplementary in value. Of course, the same restricting conditions can be obtained directly from equation (2) by observing that sin $(D’,+a’)e 1. Returning from this digression, attention may be called to the fact that when a’=0 or when n=1 formula (3), which is implicitly formula (1), gives D,—0, whereas the relation “cos $D,—= cos $D’, cos z,”, combined with the auxiliary equa- tion (2), leads to D,==:7z, for both cases. For a plane-parallel layer of relative index n, or for a prism of finite angle but with the same refractive index as the surrounding medium, 228 LH. 8. Uhier—Deviation of Rays by Prisms. it is obvious that D, cannot be a function of z,. Hence, the cosine formula again leads to false conclusions. In order to test the accuracy of the algebraic work which led to equation (3) as well as to get a concrete idea of the varia- tions of D, and D’, with 7,, the numbers in the following table were worked out for the special case where a’= 60° and n—=1'65. The data in the second column were obtained from equation (2). The numbers in the third and fourth columns were found by substituting the correspouding values of D’, from the second column in equation (1) and in “cos 4D,—= cos $D’, cos 2,” respectively. All the angles in the third column were also worked out trom formula (3). The abso- lute agreement of all the values of the true D, obtained by these two independent modes of calculation verifies equation (3). The last row of the table exhibits the superior limits of the angles for minimum deviation. The first and fifth col- umns taken together show the obliquity of the incident ray. 11 De Do pee Ci=tHD'0 4+’) Oe 51° 10'' 37". Av; 51° 10' 377. 51 10 37 soe + 5° Hil SATs 51°'29' 19" 52° 98°40) 55 eee + 10° 5QO°-4 01547 51°58" 7" 56° VAG eae Oana + 15° ion ed bya ave 58° 0117" 62° 6 3757 Su + 20° 582 22/547 54°33" 21". 69°45" 867 e559 cae + 25° 63° 15’ 56” 56° 45/°45"° 79° 01197 "eters meee” + 30° TO 247 584 59° 54/29" — 89° 55! 13s Goee aoe + 35° GUS Ra aatO cae 64° 49’ 35” 103° 20°34’ 70r 40 SHAQ? AellOs 22355414 75° ANAS" < 194° 400 17s eo an eee SAO AA 5! 21907" 0) 0" 82° 1.28" -1852 287191" 2902 eeGmae The conclusion to be drawn from the preceding argument is that either the formula “cos $D=cos $D’ cos 2,’ must be replaced by sin $D= sin $D’ cos 2, or that the cosime formula may be retained, but, when the latter alternative is followed, the various writers should state explicitly, and lay special stress upon, the fact that the D and the D’ of the cosine rela- tion are the supplements of the corresponding deviations as involved in the other equations of the subject. We think that, for sake of consistency and to avoid contusion of symbols, the formula sin 4D=— sin 4D’ cos 7, should be introduced in the text-books in place of the cosine equation. Sloane Physical Laboratory, Yale University, New Haven, Conn. W. G. Miater—Heat of Oxidation of Tin. 229 Art. XV.—The Heat of Oxidation of Tin, and second paper on the Heat of Combination of Acidic Oxides with Sodium Oxides ; by W. G. Mixter. [Contributions from the Sheffield Chemical Laboratory of Yale University. ] . Tin. Tue heat of oxidation of tin obtained by different investi- gators varies widely and the work was done before calorimetry was perfected by Thomsen, Berthelot, and others. Moreover, the constants of oxidations are required in calculating the heat of formation of sodium stannate; hence it seemed desirable to make new determinations. Depretz* found for the heat of oxidation of the stannic oxide 170000°. Dulong,t in 1838, determined the heat evolved by the union of one liter of oxygen with tin and obtained 6411°, 6325° and 6790°; mean 6509*, or for 32 grams of oxygen 145600°. Andrews,{ who first invented a calorimetric bomb, made in 1848 good determina- tions. He mixed tin with broken quartz in a copper bomb, ignited the metal with a milligram of phosphorus and found the gain in weight. His results for one gram of oxygen were 4235°, 4244° and 4210°; mean 4230°, or for 32 grams of oxygen 135360° at constant volume and 136000° at constant pressure. Likewise for the combustion of stannous oxide he obtained 4353°, 4828° and 4364°; mean 4349°, or for 16 grams of oxygen 69584° at constant volume and 69900° at constant pressure. The writer has used essentially Andrews’ method. Experiments were first made with tin from a sodium alloy. Dr. C. H. Mathewson, to whom the writer is indebted for much good material for use in investigations, made a consider- able quantity of an alloy having approximately the composition Na,Sn. This was pulverized and dropped into absolute alcohol. After the reaction had moderated, water was added gradually and then the metal was subjected to boiling water for several hours and washed thoroughly. The powder was grey and when magnified appeared to be made up of minute leaves. The stannic oxide from 1°616 grams of the metal weighed 2-060 grams, equivalent to 1°623 of tin. It was found to contain 0°12 per cent of sodium. This amount of impurity affects the heat result but slightly. For the calorimetric experiments the tin powder was placed in a weighed silver foil tray which was supported in the middle of a 500° bomb in order that, as the tray melted, the hot powder would fall through the oxygen. The weight of oxygen taken up was * Landoldt-Bornstein, Physicalisch-Chemische Tabellen, refer to Ann. Ch. Phys., xxxvii, 180. This reference the writer has not been able to find. +C. R., vii, 871. ¢ Phil. Mag. (8), xxxii, 321. Am. Jour. Sci.—FourtH Series, Vou. X XVII, No. 159.—Marca, 1909. 1 230 W. G. Miater—Heat of Oxidation of Tin. derived from the weight of tin taken, of oxides formed, and of ferrous-ferric oxide from the iron used for ignition. The experimental data are as follows: 1 2 A i es SS tenet gee ets 8:121 grams 11°070 grams ‘‘ equivalent to oxygen com- bined!) 2 e Sei Se coe W122 oe 9°3640. 2" Oxygen combined.) {ots 2. ONO; pris 255 dS ae Water equivalent of system.__. 3631: rt oe GABE Temperature interval {222 2)° 0 22 2°366° 3°239° Heat observedeiin: Seer nee 8591° 12 os * ofioxidation or irons 225 5- — 80° — 80° 8511° Lio ae Hor d oramyoroxyoen Ss 4062) 2. 4456° 4444¢ The combustions were evidently incomplete as indicated by the figures and by the fact that there was formed a considerable amount of a black substance along with the white stannic oxide. The results are 4 per cent higher than those obtained with tin foil in experiments 3 and 4. It might be surmised that tin separated from a sodium-tin alloy is an allotropic form and it may be when the separation is made at a low temperature, but the powder which had been heated to 100° is the ordinary modification, for, as shown later, it gives the same heat when burned with sodium peroxide as ordinary crystalline tin. The high result is evidently due to the forma- tion of a considerable amount of stannous oxide. but the heat effect of Sn+O is less than that of SnO+0O, and hence it appears probable that the two oxides formed in the com- bustion had combined with evolutions of heat. Moreover, the sesquioxide of tin is known and is dark colored. The next experiments were made with tin foil, which a qualitative analysis showed to be quite pure. It was also tested as follows: 2°911 grams were treated with nitric acid, the latter removed by evaporation, the residue digested with dilute nitric acid and washed on a filter and finally heated over a blast lamp until the weight was constant. The stannic oxide obtained weighed 3°700 grams, equivalent to 2916 grams of tin. (Sn=119.) For the combustions the foil was placed in loose rolls in the bomb, which was then filled with dry oxygen at a pressure of 12 atmospheres. The conditions were the same as in experiments 1 and 2 except that the foil exposed a larger surface to the oxygen. The stannic oxide resulting was in the form of a porous cake which was brown- ish on the surface but white in the interior. The entire cake W. G. Miater— Heat of Oxidation of Tin. 231 was a mass of elongated microscopic crystals. Professor W. E. Ford of the Mineralogical Laboratory has kindly examined the crystals and found them too small for measurement but having the optical properties of cassiterite. It should be stated that a small portion of the stannic oxide was deposited on the upper surface of the bomb in the form of white powder. After a combustion the oxide was transferred to a platinum dish and the water used in washing out the last portions was evaporated. The weight of the oxygen which combined the tin was found as already described. ‘The follow- ing are the experiments: 3 4 ire ee eee 1168 orams 3 14:055 granis ** equivalent to oxygen com- SUI ae rie Reale 15°042 a 13°919 i Weayeen combined. 962 22.2 A045 8 BI a Water equivalent of system... 3548: ct 3058" e Temperature interval .-._----- 4°893° 4-4 10° Pieper Ouservied a0) a 17360° 16132° Sa gOr Oxidation OL Iron ~- 2. 41° 40° hislo% 16092° Hert sram. of oxygen -___..- 4282° 4293° The average of the results is 4288° for one gram of oxygen combining with tin to form stannic oxide. For 32 grams it is 137200° at constant volume and 1387800° at constant pressure. It will be observed that the tin in the form of foil was almost completely oxidized. Andrews’ result was 136000° at constant pressure. In his experiments there may have been formed some amorphous stannic oxide which would lower the heat effect. His result, however, agrees well with the writer’s. Stannous Oxide. A number of preparations of stannous oxide were made by different methods but only two appeared to be good enough for the purpose. The first used was made by adding an excess of ammonia to a solution of stannous chloride and then heating the mixture several days on a steam bath. The dark crystalline mass was washed thoroughly and dried at 100° and then heated in a current of dry carbon dioxide to about 400° as long as water and ammonia came off. The product was almost black, showing under the microscope minute crystals but no amorphous powder. It contained considerable stannic oxide, a trace of ammonia, and 0°09 per cent of water. Three determinations of the heat of oxidations gave respectively : 4668°, 4667° and 4632°, a mean of 232 W. G. Miater—Heat of Oxidation of Tin. 4656° for one gram of oxygen taken up or 74500° for sixteen grams. The result was thought to be high and therefore another lot of stannous chloride was prepared as follows: about 400 grams of pure stannous chloride were dissolved in four liters of hot water and a solution of pure sodium hydroxide was added in sufficient quanity to dissolve part of the stannous hydroxide formed. The mixture was kept hot until most of the white particles had disappeared. The product was washed by decantation in order to remove the smaller particles present. The stannous oxide was in the form of minute dark erystals. It was free from chlorine and sodium; dried at 100° it con- tained 0°41 per cent of water, which was determined as follows : a weighed portion was burned in dry oxygen in order to attain a high temperature and the water was absorbed in a chloride of calcium tube. The determination of stannous oxide was made thus: 1°1193 grams of substance were heated in air and oxygen. The stannic oxide formed weighed 1°2425 grams and the observed gain in weight was 07123 gram. Adding to this last number 0°0046 gram of water present before burning we have 0:1276 gram of oxygen taken up, which is equivalent to 96°2 per cent of SnO. For the calorimetric work the stannous oxide, dried at 100°, was placed on a silver foil tray which was supported at the top of the lower silver cup or lining of a 500° bomb and then the cup and contents were counterpoised ona balance. After a com- bustion the cup and contents were heated to expel moisture, - allowed to cool and then the increase in weight noted. At the time of a combustion the tray melted and the oxide fell to the bottom of the cup, where it was found in the form of a porous white crystalline cake. The experiments were as follows: 8 9 10 Substance taken .__.--._- 30°06 30°89 30°58 grams Amount + 0°962 = SnO_.. 28°92 29°72 29°49 © ef SnO equivalent to oxygen COnswumMed) 42. eae 28°74 29°74 294 pn Increase in weight -._---- 3°340 S40 341 5e. ee Water in substance taken - 07123 0°126 O12 eae Fe,O, from iron___-.. toe (0-056 ~— 0-056. 0-055 ae Oxygen consumed _--- -.--- 3°407 3°525 3484 « Water equivalent of system 3422: 3430° 3476° nies Temperature interval - _--- 4°422° 4°541° 4°469 9 | Heat observed .----.----- 15133° 15576° 15534¢ “¢ of oxidation of iron_- — 64° —64° —64° —— oe 15069° 15512° 15470° W. G. Mixter— Heat of Oxidation of Tin. 233 For 1 gram of oxygen con- sumed: 425 See 4493° 4401° 4443° “ 1 gram of SnO in sub- stance taken.___-_.- 521° pe 521° The average is 4417° for one gram of oxygen and for 16 grams it is 70672° at constant pressure and 71000° at constant volume. The mean for one gram of SnO in the substance taken is 521°; for 135 grams 70335° at constant volume. Evidently the stannous oxide was nearly all burned to stannic oxide. Andrews’ result was 69000 at constant pressure. Combustion of Tin with Sodium Peroxide. The metal used in the next three experiments was from the same lot taken for experiments 1 and 2 and prepared from the sodium-tin alloy. Carbon was added to the mixture in experi- ment 10 to ensure a high temperature, but it was not required, as the other experiments prove. No metallic tin was found in the residues of the following determinations : iL 12 13 timers en OE os he ae 3°000 5:000 8°000 grams SaROOMn ns. es 0°330 Ne pie ores a Sodium peroxide .._-_---. 10° 10° 18° Water equivalent of system 3060: 3012° 2987- : Temperature interval _._-- 2°283° oils Be0 SG aa Heat observed _._-.-._- Ee 6986° 5635° 9218° “of oxidation of carbon —8663° ari eee 66 73 66 iron... = 30° 206 — 4° “< “* oxygen set free or paken Ups. 22 —+46° —4s8° + 82° 3339° 5617° 9260° Homi eram of tin 2 22 1113° 1115° 1157° As the tin from the sodium-tin alloy gave more heat when burned with exygen than that known to be the common modi- fication, tin turnings were made by fastening a cylinder of tin in a lathe so that it rattled. Small chips came off which were separated from the coarser process by sifting. The following are the experimental data: 14 15 BBS oor ie ee re 8°241 grams 10°175 grams Pee tOG. WUTNECG sion ee 5) ke OD 24g O.0G4 SS OMINCO p= sc piwe as 7°998 “ec TOPE Bodinth. peroxide {2 li Pie e 25° a Water equivalent of system... 3759: e 3816° ee Temperature interval _______- 2-383." 3°020° 234 W. G. Miaxter— Heat of Oxidation of Tin. Heatvobserved = os. ae 8957° 11525° “ of oxidation ie ‘OMS, ee —64° oe “ S oxygen takenwup) 2222 0 — 90° 8893° ear Bor lL -eram Of tino 4 77s) eee Hie 1125° The mean of the five results is 1124; the average for 119 grams of tin is 183756". Evidently the tin from the sodium- tin alloy is the common modification. Amorphous stannic oxide used in the next two experiments was made by heating metastannic acid over a ring burner until the weight was constant. Sulpbur was used to give the tem- perature requisite and to reduce the sodium peroxide to oxide. 16 17 Stannic oxide, amorphous. - - -- 9°955 grams 7907 grams i Uae ChAMmO eG. 2 aes 12045..." 05832 78 = ae Combined: spas SO a 132428 Water equivalent of system... 2987: yee 2987- e Temperature interval._.._.--- 2°500° Pay ia Heat‘observed 2s. yee eee 7467° 6961° “of oxidation: ofirom 2 72- —48° — 48° arts 5 “ sulphur. - Oil Oo ae BE Ose yuan eri nee. + 75° ap ae 2223° LE For 1 gram of stannic oxide- -- 255° 2306 The mean is 246° and for 151 grams of amorphous stannic oxide it is 87100°. Summary of results. Sn + O, = SnO,(erystalline) +... 22222 is azoue Sn (crystalline) + O =SnO(crystalline) + -.. 66200° SnO(crystalline) + O = SnO, (crystalline)+-. _71000° SnO, (amorphous) = SnO (crystalline) as eee 1700° gNa.O, + Sn = Nain. Na OF ee 133800° 2Na, 0+20= 2Na, Oe ie 38800° Na,O + Sn 4+20—Na sone sb. cas Ss Pe Sn + O, = SnO (crystalline) sete te B33,210)0'° Na,O + “SnO (crystalline) = Na,SnO, Se 35400° Na,O + SnO,(amorphous) = Na,SnO, + ---- 37100° Ford—Neptunite Crystals from San Benito Co., Cal. 235 Art. X VI.—WNeptunite Crystals from San Benito County, California ; by W. E. Forp. Mistorical.In July, 1907, a new mineral, called benitoite, was described by Prof. G. D. Louderback in a bulletin of the Department of Geology of the University of California.* In the same article a short preliminary description of what was then thought to be another new species was given and to which the name carlosite was provisionally assigned. Mr. Lazard Cahn, in the summer of 1907, first called the writer’s attention to the fact that this mineral was identical with the rare species neptunite found previously only in the Juliane- haab district, Greenland. This identity of carlosite with nep- tunite was announced by Prof. Louderback at the meeting of the Geological Society at Albuquerque in December, 1907, BirGeoe: and a short note to the same effect was later published by W. E. Blasdale in Science for August 21st, 1908. But beyond this no description of the occurrence has so far been published. Through the courtesy of Mr. Cahn and Mr. Milton G. Smith, *Vol. v, No. 9, 149, 1907. 236 Ford—WNeptumte Crystals from San Benito Co., Cal. the writer has been able to examine a large number of the neptunite crystals from this locality and it was thought that a brief description of them would be of interest. Occurrence.—The neptunite crystals oceur associated with those of benitoite, both minerals being embedded in a white matrix of erystalline granular natrolite. The neptunite crys- tals that are now in the Brush Collection vary in size from slender prismatic crystals of only a few millimeters in length to those of 25°" in length and as much as 7™™ in thickness. In general the crystals are brilliant black in color, but wherever they have been fractured they show by internal reflections the red-brown color which is characteristic of the mineral when im thin section. Crystallographic.—The crystals from San Benito County are excep- tionally uniform in their habit, the following series of forms being found on almost every crystal studied: a(100), m(110), s(111), 4 (112), 0111), g* (211), p(811). The crystals are prismatic in habit, quite different from those first described by Flink* from Greenland, but more like a later type described by him+ and resem- bling still more a erystal figured by Wallenstrém.{ The habit of devel- opment of the California crystals is represented in the figures which have been drawn from specimens in the Brush Collection. Figure 1 repre- sents the commonest type in which the forms present are: prism, m (110), prominent, @(100) in narrow trun- cations, the base, ¢ (001) very small, as. also ¢ (111) and 2112), The prominent terminal faces are the . negative pyramids o (111), the new form g(211) and p (811). Figure 2 shows a slight modification in the development of these forms, and figure 4 shows the same forms, with the exception of g which failed, but in an unsym- metrical development. which is unusual on the crystals. This figure was drawn by Mr. D. D. Irwin. Figure 4 is a doubly terminated crystal, lke figure 2, half embedded in its matrix of white natrolite. The faces of the crystals studied were, as a rule, bright and gave excellent reflections on the goniometer with the exception of the new form g(211). In every erystal * Zeitschr. Kr., xxiii, 346, 1894. + Medd. om Gronl., xxiv, 120, 1902. t Geol. For. Forh., xxvii, 149, 1905. ine, a Ford—Neptunite Crystals from San Benito Co., Cal. 287 observed this face was dull in luster and distinctly curved, and only approximate measurements could be obtained from it. Tts symbol was determined, however, by its zonal relations, for it was found to lie at the intersection of the pyramid zone a (100)—s (111) —0 G11)—p (811) —a@ (100) and the zone m (110) —7(112)—m (110). This form g is new to the mineral, for although Boggild in Mineralogia Groenlandica, page 506, lists such a form as p (211) it is evidently a misprint, for in the original article by Wallenstro6m* the form referred to is given as p(311). The various forms were itpaunad by the follow- ing angles: Meas. Cale a (100) A m(110) 49° 59" 49° 53° a@(100) A e€ (001) 64° 224! 64° 29’ m(110) A s (111) B85 0! Si Oey m(100) A © (001) 73° 49! ee TS AO m(110) A @ (112) 78° 26' 78° 234! m(110) A o (111) Soe Ay 54° 58! m(1l0) A g (211) peel) One 40° 282" a(100) A p (811): 39° 384’ oe Ol Figure 5 shows in stereographic projection all the crystal BiG. 3: a (100) forms of neptunite that have been listed. Those observed on the Greenland crystals are indicated by solid dots, while the * Loe. cit. 238 Ford—Neptunite Crystals from San Benito Co., Cal. forms found on the specimens from California are indicated by open circles. , Optical.—F or the optical study of the material a thin sec- tion was first cut parallel to the symmetry plane (010). On examination between crossed nicols it was found that one extinction direction was inclined to the c-axis of about 24° in the obtuse angle 8, while the second direction of extinction very nearly coincided with the a-axis making an angle of 1° 38’ above it in front. The direction of greatest elasticity of the section corresponds to the extinction direction which nearly coincides with the a-axis. The section showed very strong pleochroism, the ray vibrating parallel to the direction a being colored yellow while the one vibrating parallel to c was a deep brownish red. These relations are shown in figure 6. Two other sections were cut, each being normal to one of the Fie. 6. nivel 7s Fie. 8. red. b Ol1o extinction directions of the section parallel to 6 (010). In the section normal to the a-direction, or nearly normal to the a crystallographic axis, it was noted that the extinction direction which was parallel to the b-axis was the direction of greatest elasticity in the section or the direction of intermediate elas- ticity 6 of the mineral. This section showed in convergent polarized light an interference figure with a large axial angle, the optical axes lying in the symmetry plane of the crystal. This section showed no marked pleochroism, rays vibrating parallel to the two extinction directions being both colored a dark red. These relations are expressed in figure 7. _ The third section was cut normal to the direction ¢ deter- mined in the section parallel to 6(010) and in its orientation was nearly parallel to c(001). This section showed an inter- ference figure with the optical axes lyimg in the symmetry fe ord —Neptunite Crystals from San Benito Co., Cal. 289 plane of the crystal. As the angle between them was small it follows that the direction c, the normal to the section, is the acute bisectrix and the mineral is positive. Rays vibrating parallel to the 0 erystallographic axis were colored red, while those vibrating in the symmetry plane were yellow. These relations are shown in figure 8. The above results differ from those given in the original description in the position assigned to the axial plane. Flink describes the optical orientation of the Greenland neptunite as follows:* “The plane of the optical axes is perpendicular to the symmetry plane and the acute bisectrix forms an angle of 18° with the vertical axis in the obtuse angle 6.” A critical reading of his description would suggest that the discrepancy noted above was probably brought about by an accidental turn- ing of one of his sections so that the true orientation was reversed. To translate further from his description: “In the first section orientated parallel to the symmetry plane one extinc- tion direction forms with the vertical axis an angle of 18° in the obtuse angle 8. The rays vibrating in this direction show the greatest absorption and the color is deep red brown. The rays vibrating perpendicularly to this direction are less absorbed and the color is yellow-red. The same section shows _ also in convergent polarized light an axial figure with a large angie between the optical axes.” With the exception of the last statement the description agrees with that given above for the California mineral. Flink describes the second section which he cut as follows: ‘‘In the second section, orientated perpendicular to the symmetry plane, and making an angle of 72° with the orthopmacoid and. 74° with the base, the rays vibrating parallel to the symmetry axis are the least absorbed and the color is yellow-red. The rays vibrating perpendicu- larly to the symmetry axis and in the symmetry plane are more strongly absorbed and the color is dark red. This section shows in convergent polarized light an axial figure with a -small angle between the optical axes.” It will be noted that the elasticity direction which is common to the two sections, namely the one lying in the symmetry plane and making a small angle with the q@-axis, is said in the first case to show the least absorption and to be colored yellow-red; and in the second case the greatest absorption with a dark red color. This discrepancy could be explained and the optical orienta- tion of the Greenland mineral be brought into conformity with that from California, if Flink’s second section was considered to have been accidentally turned 90° from its true orientation. The statement that an axial figure with large optical angle was * Zeitschr. Kr., xxiii, 350, 1894. 240 Ford—Neptunite Crystals from San Benito Co., Cal. obtained from the section parallel to (010) might be explained by the fact that often in biaxial crystals what appears to be an interference figure with a large axial angle can be obtained from sections that are cut parallel to the axial plane. Attempts were made to measure the indices of refraction of the mineral, but on account of the dark color of the material they failed. The average index of refraction was obtained in the following manner: Small fragments were observed under the microscope immersed in various mixtures of a monobrom- napthalene and methylene iodide until one was obtained whicli by use of the Becke method was found to be very closely of the same index of refraction as the neptunite. The index of refraction of the liquid was then determined by immersing in it fragments of other minerals with known indices of refrac- tion until the same result was obtained. In this way the average index of refraction of the neptunite was found to be close to 1°70. An approximate measurement of the axial angle was made by immersing the section cut perpendicular to the acute bisec- trix in a monobrom-napthalene (7=1°6583) and using a small axial angle goniometer placed on the stage of the microscope. The measured angle (2H) was approximately 50°, which would give 2E=90°. Assuming that @=1°7, this would give the , axial angle 2V =48° 40". Dispersion of the optical axes was noted, v>p. Chemical.—A qualitative examination of the Califounin neptunite shows its substantial agreement with the analyses given of the Greenland material. It is hoped shortly to be able to make a quantitative analysis and to present its results in a subsequent paper. Mineralogical Laboratory of the Sheffield Scientific School of Yale Uni- versity, New Haven, Conn., Jan. 29, 1909. Gooch and Bosworth—Silver as the Chromate. 941 Arr. X VII.— The Gravimetric Determination of Silver as the Chromate ; by F. A. Goocu and Rowxtanp 8. Bosworru. [Contributions from the Kent Chemical Laboratory of Yale Univ.—cxcv. ] Ir has been shown in a recent paper from this laboratory* that the precipitation of silver chromate from the solution of a soluble chromate made faintly acid with acetic acid may be carried to completion by the addition of silver nitrate in con- siderable excess; and that the exact determination of the chrom- ium of a soluble chromate or dichromate may be effected by treating with silver nitrate the solution of either salt, adding ammonia to alkalinity and then acetic acid to faint acidity, transferring the precipitate and washing it in the filtering erucible with a dilute solution of silver nitrate until foreign material other than that reagent has been removed, fnishing the washing with a small amount of water applied judiciously in portions, and weighing the dried or gently ignited residue of silver chromate. The success of this process turns upon keeping the chromium at the moment of precipitation essen- tially in the form of chromate rather than dichromate and in taking care that an excess of silver nitrate shall be present nearly to the end of the washing. The present paper deals with the conditions under which, in reversal of the process just described, silver may be precipitated completely as the chromate: In the first experiments to be described, a solution of silver dichromate was added gradually, either in slight excess or in considerable excess, to a solution of silver nitrate maintained at the boiling point; the mixture was cooled and treated with ammonia until the precipitate first formed had been dissolved ; acetic acid was added to faint acidity; and the precipitate was settled for a half-hour, filtered off on asbestos in a perfor- ated crucible, washed with a little water, dried and weighed. In every case the weight of silver chromate found was defic- ient and the testing of the filtrate with hydrochloric acid showed the presence of a soluble salt of silver. The errors amounted to several milligrams, varying with the conditions. Dilution of the original solution and prolonged washing with water increased the error. Admixture of alcohol was with- out appreciable effect upon the solubility of the precipitate. Evaporation to dryness and transfer by a dilute solution of potassium dichromate, and a final washing with water used judiciously in small portions, tended to diminish the amount of soluble salt, but this treatment never reduced the error of loss *Gooch and Weed : this Journal, xxvi, 85, 1908. ~ 242 Gooch and Bosworth—Silver as the Chremate. below two or three milligrams for volumes approximating a hundred cubic centimeters. Solution of the first precipitate in ammonia and reprecipitation by boiling to low volume to remove the excess of ammonia failed to overcome entirely the solubility of the silver salt, which appears to be due to a tend- ency on the part of the ammonium chromate to pass to the condition of dichromate with loss of ammonia from the boiling solution. 3 In the next experiments, therefore, potassium chromate was used as the precipitant. In Table I, A are given the details of experiments in which an excess of potassium chromate was added to silver nitrate, the solution boiled, the precipitate transferred to the asbestos mae Mae perforated crucible by means of a dilute solution of potassium chromate and washed with small portions of water, and the residue after drying with gentle heat weighed as silver chromate. In these TaB_eE I. Silver Error taken as K.CrO, Age.CrO, Silver in terms AgNO; used weighed found of silver ais Sa Na), EO, Volume Weight Volume of solu- of of solu- tion silver tion Weight em?. erm. Cm erm, grm. erm. erm. (eA Precipitation by KeCrOx,. 15 0°1652 50 0°3 0°2536 0°1649 —0°'0003 10 O'1101 50 0°3 0°1693 O°1101 0°0000 25 01437 50 O8 0°2200 0°1436 —0:0001 25 0°1437 00 0'3 0°2210° 0°1437 0°0000 Bias Precipitation by K20rO,., treatment with NH.OH and evaporation to dryness. 25 0°1348 00 0°3 0.2077 0°1351 + 0°00038 30 0°1618 10) 03 0°2500 0°1626 +0°0008 30 0°1618 30 0°3 0°2520 0°1639 +0°0021 C ate Precipitation by K2CrO., treatment with BENG and boiling to a volume of 10-15", 25 0°1576 50 0°38 0:2422 OM difo —0'0001 25 0°1576 50 0°3 0°2414 0°1570 —0°0006 50 0°3152 50 0°3 0°4852 0°3155 + 0°0003 50 03152 50 0°3 0°4843 0°3149 —0°00038 50 0°3152 50 0°3 0°4847 0°3152 0°0000 D Precipitation by K2CrO,, treatment with NH,OH and boiling to a volume of 10—15°"*® in presence of 1 grm. of sodium nitrate. 10 Ce eiG) i 50 0°38 0°1698 O°1101 15 0°1652 50 2073 0°2536 0°1649 0°0000 —0°0008 Gooch and Bosworth—Silver as the Chromate. 943 experiments no silver was found in the filtrate, but the pre- cipitate was not so coarsely crystalline and easily washed as when deposited by removal of ammonia from an ammonia- eal solution. In the other experiments of Table I, therefore, the first precipitate was dissolved in ammonia and reprecipi- tated by boiling the solution: in those of B the evaporation was carried to dryness, and in those of C the concentration was stopped when a volume of 10-15°™* had been reached. In all these experiments precipitation was complete, the fil- trates giving no test with hydrochloric acid for a dissolved sil- ver salt. , The high results obtained in the experiments of B are no doubt due to the inclusion of foreign matter in the silver chro- mate, which is left in caked condition by the process of complete evaporation. The better results in the experiments of C are apparently due to the fact that in them the evaporation was not pushed too far. The experiments of D show that the pres- ence of a gram of sodium nitrate has no appreciable effect upon the solubility of the silver chromate. It is plain that- the precipitation by potassium chromate in neutral solution is practically complete and that accurate determinations may be made by filtering at once, or by dissolving the precipitate in ammonia, reprecipitating by boiling to a volume of 10-15, and then filtering, drying, and weighing. In many cases it is desirable to determine silver present -in solutions containing free nitric acid. The effect of free nitric acid upon the process was therefore next studied. A few qualitative experiments showed that the solvent action of nitric acid may be obviated by taking care to use the precipitant, potassium chromate, in such amounts that an excess of it shall be present after taking up the nitric acid to form potassium dichromate. The details of a few of these experiments are giving in the accompanying table. Tasuxe IT. K.CrO, a SSS SSS SS To form Theo- Ag in To form K.Cr.0, retically Ag AgNOs HNO; AgeCrO, with HNO; required Present in filtrate erm. erm. erm. erm. erm. erm. 071376. . 0°063 0°1241 On 946; 023187" 220.3172. Kound 071376. .0°063 0°1241 O1946. 2: Olsa.0°3172- « Found 0°0550 0:063 0°0496 O19460"% 0-94490- 220-3179) None 0°0550 0°063 0°0496 01946 0°2442 0:°3172. None 01376 0°063 0°1241 0:1946 0°3187 0°3806 None 0°1376 0:063 0°1241 071946 0°3187 0°4758 None 01376 0:095 0°1241 0°2919 0:4160 0°4758 None OI376 x 0-126 0°1241 0°3892 05133 06344 None 0°1376 07158 0°1241 0°4865 0°6106 0°7930 None 244 Gooch and Bosworth—Silver as the Chromate. In Table III are given the results of quantitative experi- ments in which precipitation was effected in presence of nitric acid, with care to insure the necessary excess of potassium chromate. In the experiments of A the precipitate was fil- tered off at once, without solution by ammonia and reprecipita- tion by boiling: in those of b the ammonia treatment was made to convert the less crystalline precipitate to better form for filtration and washing. | ) TasieE III. Silver taken KeCrO.4 as AgNOs used SSS SS (a SSS SS Volume Volume HNO; _ Error of solu- of solu- -———s — Ag.CrO., Silver in terms tion Weight tion Weight Vol. Weight weighed found of silver em. erm. CM: 2 6 orm. ce jeme: erm. erm. erm. grm. A Precipitation by K2CrOx, in presence of HNOs. 25 0°1355 50 0°9 10 07182 0°2091 0°1360 +0°0005 2 0°1355 50 0-9 10 0°182 0°2081 0°1353 —0-°0002 25 0°1358 50 0°9 10 0°182 0°2090 0°1360 +0°0005 | 25 0°1355 50 09 10 0°182 0:2075 0°1849 —0:0006 25 0°13855 50 0-9 10 0°182 0°2090 0°1860 +0:0005 B’ Precipitation by KeCrOz in presence of HNOs, treatment with NH,OH, and boil- ing to a volume of 10-15 °™, 295 0°1348 50 0°6 10 + =0°063 0°2076 0°1350 -+0:0002 25 0°1348 50 0°6 10 0°063 0°2068 0:1844 —0-0004 25 01348 50 0°6 10 0:063 0:2072 01347 —0:0001 25 0°1348 50.2. 056 10 0°063 0:°2074 0°1348 0°0000 25 0°1348 50 6°6 10 0063 0:2070 0:°1346 —0:0002 So it appears that from solutions of silver nitrate, containing free nitric acid, potassium chromate precipitates silver chromate completely, provided enough potassium chromate is present to take up the nitric acid with formation of potassium dichromate as well as to form the silver salt. The precipitate, filtered at once or brought to better crystalline condition by treatment with ammonia and boiling of the solution to small volume, may be transferred to the asbestos filter by dilute potassium chromate and washed by small portions of water without appreciable loss. The weight of the residue of silver chromate, dried at gentle heat, may be taken asa very fair measure of the silver originally present. J. Trowbridge—Doppler liffect in Positive Rays. 245 Art. XVIII.— The Doppler Hffect in Positive Rays; by JoHN TROWBRIDGE. Tue discovery of canal rays by Goldstein, and that of the Doppler effect in these rays, marks an epoch in the study of the discharge of electricity through gases; for before these discoveries the multitude of confusing effects which arise in the space between the anode and the ee eathode made it difficult to observe tase any translation movement. The space, however, behind the cathode is comparatively free for the passage of the positive ions. We now recognize, in addition to the positive rays behind the cathode— the canal ray—retrograde positive rays which are directed to the anode, or rather away from the cathode in the direction of the anode.* This later discovery leads one to expect that the Doppler effect should be found also between the anode and the cathode. The result of my study shows that the effect does exist in this region and indicates a movement away from the cathode and toward the anode. The form of tube I have employed is represented in fig. 1. The slit of the Rowland grating was at X for the retrograde rays and at Y for the canal rays; A being the anode and C the cathode. The Rowland grating gave, in the order of spec- trum I employed, six Angstrém units to nine-tenths of a milli- meter. The effect was observed with respect to the hydrogen line 4861°5 and the change in refrangibility was measured by comparison with the solar spectrum, which was photographed immediately beneath the gaseous line without changing the jaws of the slit. The amount of the change in refrangibility was sensibly the same as in the canal rays. The difference of potential between the anode and the cathode varied between five thousand and ten thousand volts; and the current from ten to five milliamperes furnished by a storage battery of ten thousand cells. A current of running water provided a large and steady resistance. The appearance of the discharge at the cathode has often been described. The cathode appears to be the base of two * Wehnelt, Wied. Ann., 1899, p. 421; Runge and Baschen, Wied. Ann., lxi, 1897, p. 644; Paschen, Wied. Ann., xxiii, p. 247; Villard, Comptes Rendus, exliii, p. 678, 1906; Goldstein, Phil. Mag., March, 1906; Jacob Kunz, Phil. Mag., July, 1908, p. 161; J. J. Thomson, Oct., 1908, p. 657. Am. Jour. Sci1.—FourtTH SERIES, VoL. XX VII, No. 159.—Marcg, 1909. ity A xX Y C 246 JS. Trowbridge—Doppler Lffect in Positive Rays. rose-colored cones of light, the apex of one directed to the anode and the apex of the other toward the canal region. The body of the luminous cone in the space between the anode and the cathode is, so to speak, a solid, while that in the canal region, or back of the cathode, is made up of a collection of tubes which in a short region come together at the apex of the cone, and in a more extended region spread out in a diffused manner. When the cathode is unperforated the rosy glow, which in the case of hydrogen characterizes the canal rays, emanates from the central portion of the aluminium cathode; it is no longer conical in form, or rather resembles a frustrum of a cone, the base directed to the anode. It does not extend as far toward the anode as the conical discharge from the per- forated cathode and is not so bright. With the unperforated cathode and the slit placed at X, no Doppler effect was seen. When, however, the cathode was perforated the effect was very 1g, 2 evident and indicated a movement toward X which was equal in amount to that observed in the canal region toward Y. More- over, the photographs showed, when the light was observed at X, a line on each side of the ordinary stationary hydrogen line ; — my observations were confined to 4861°5. There was evidently a movement toward the anode, and a movement away from it at the cathode. When the observations were conducted at Y, the same phenomenon was observed: a stationary hydrogen line and a diffuse line separated from the stationary line by a blank space on each side of the stationary line—indicating a movement toward the cathode and away from it. In fig. 2, a and 6 are photographs, ¢ is a drawing which represents effects too feeble to be strongly reproduced from the photographs—effects, how- ever, which are very evident on the negatives @ and 6. The J. Trowbridge—Doppler Liffect in Positive Rays. 247 slit was a broad one in order to show differences of illumi- nation. The light was strongest at the orifices. When the observations were conducted by placing the slit of the spectroscope so that the light at the perforations did not enter the slit—in other words, placing it obliquely to the band of light—the companion of the stationary line which indicated a movement away in each case, from the slit, was not discernible. The effect took place at the orifices. The positive particles jostling though these orifices and mutu- ally repellent transmit moverients, like those resulting from elastic particles in impact, in opposite directions and those driven in the direction of the anode meet others coming toward the cathode. There results a maximum of radiation of greater refrangibility which is separated from the refrangi- bility of the stationary hydrogen line by a less luminous space. When glass tubes are inserted in the orifices through which the canal rays pass and the back otf the cathode is protected by glass connected to these tubes and to the wall of the dis- charge tube, the canal rays are still obtained. This proves that these rays are produced immediately in front of the cathode that is on the side toward the anode, or in the orifices. I incline to the belief, as 1 have stated, that the jostling in the narrow orifices accounts for the change in refrangibility. In all discharge tubes strize are seen opposite to the edge of the cathode on the glass. These strize can be localized at a definite point by bringing the edge of the dise of the cathode near the wall of the tube; and we then have a source of positive rays which is analogous to that formed by pushing a glass tube surrounding the anode into the Crookes space.* The heating and oxidizing effect from the positive particles of these strize is very marked, especially when the canal region is small, and is much greater than any effect produced by the canal rays in a possible rebounding from the end of the canal region. The photographs of cathode discs exhibit this effect of the positive rays coming from the striz. In fig. 3, No. Lis a photograph of the back of a cathode made of aluminium formed from as pure clay as could be obtained. The disc was ‘75™™ thick and the hard surface formed by the iron rolls was left upon it. The heat from the positive rays coming from the strize caused the occluded gases of the aluminium to form blisters on its surface. No. Il represents the back of a cathode formed from the same quality of aluminium as in case [, except that the plate of aluminium was treated with nitric acid to remove any trace of iron coming from the rolls. The surface thus lost its polish and hardness. A very black deposit formed *K. Wiedemann, Wied. Ann., lxiii, p. 242, 1897. 248 J. Trowbridge—Doppler Lffect in Positive Rays. under the effect of the positive rays of the strize, which was probably carbon from the aluminium. In III the cathode was formed from ordinary commercial aluminium 1°5™™ thick. It represents the blackening which results from long running of HiG. 3. Hig. 45 the} discharge. At increased exhaustions and during this long use of the tube the strize shift their position, and the back of the cathode shows a general discoloration. No. IV repre- J. Trowbridge—Doppler Kffect in Positive Rays. 249 sents the front of the cathode of fig. 3. The center is bright, while the edges are discolored. Goldstein has noticed that positive rays remove deposits. Fig. 4 is a photograph of the canal rays which shows also the luminosity on the back of the cathode produced mainly by the striz. The order of spectrum produced by the Rowland grating gave an interval of ‘9 millimeter to six Angstrém units. The approximate interval between the Doppler effect on both sides of the stationary hydrogen line 4861°5 was three Angstrom units; the difference of potential between the anode and the cathode varied from 6000 volts to 10,000. The current ran from 10 milliamperes to 5. A storage battery of 10,000 cells was employed. The internal diameter of the discharge tubes was 3°". The distance between X and ©, fig. 1, was 6. The distance between OC and Y varied from 4°™ to 10. Jefferson Physical Laboratory, Harvard University, Cambridge, Mass. 250 G. R. Wieland—Armored Saurian from the Niobrara. Art. XIX.—A New Armored Saurian from the Nanna: : by G. R. Wieianp. Tue greatest American storehouse of fossil marine verte- brates is doubtless in the Niobrara chalk of western Kansas. But despite the fact that many of the diverse forms there rep- resented must have lived near and frequented the shores of - the Niobrara sea, very little evidence of even presumably true land forms has thus far been obtained. The best known form to be regarded as land, or at least lacustrine or fluviatile, is the Hadrosaurus agilis of Marsh from the Smoky Hill river. Though the type of this dino- saur includes considerable portions of the skeleton, only a single individual has ever been recovered. In fact, in the Univer sity Geological Survey of Kansas, vol. iv, Professor Williston Says, in speaking of the Dinosauria: “ But a single specimen (that is Hadrosaurus agilis) has ever been found in the state, so far as I am aware, though the animals must have lived here about the shores of the Cretaceous seas in oreat abundance.” And although collecting in the Niobrara has been especially active during the past ten years, no further examples even doubtfully referable to Dinosauria came within my knowledge — until about two years ago. Then [ noted amongst turtle material sent to the Yale Museum from the Hackberry Creek region by Mr. Charles H. Sternberg, and referred to me for study, the two paired and presumably caudal, or else cervical, dermal elements shown in figure 7, 7a. On the basis of such slender evidence it was of course not possible to say whether a crocodilian was indicated, or even some remote progenitor of such a turtle as J/zolania. Now, however, we are enabled to present some clearer evidence for the presence of a second Dinosaurian genus in the Niobrara. This last season Mr. Sternberg secured, five miles south of Castle Rock and three miles south of Hackberry Creek, six dermal scutes of a form quite certainly dinosaurian. These plates later came into my possession and have been donated to the Yale Museum. The name /Hverosaurus Sternbergi is assigned them in honor of their tollector. It is thought that other fragmentary specimens have been observed, so that it is probable that further material will yet be obtained. In the excellent figures 1-7a of the present fossil scutes, drawn by Mr. R. Weber, the principal characters may at once be discerned. The scutes are all shown one-third the natural size in the figures 1-T7a. The bones shown in figures 1-8 are odd, that of No. 3 being merely a tubercle with a fine right-angled stria- tion on its lower surface. . Those shown in Nos. 4 and 5 are a pair, but other elements must have intervened; while the two fused elements shown in No. 6 form an isolated asymmetrical - 251 G. R. Wieland—Armored Saurian from the Niobrara. IY 252 G. LR. Wreland—Armored Saurian from the Niobrara. plate. In all the foregoing except the tubercle the thickness is much as seen in the transverse section No. 2b. The more or less median ridge is sharp and runs the entire length, being of much the same height throughout its course, and terminat- ing as a sharp backwardly projecting shghtly upturned spur. The height of the ridge is from one to one and a half centi- meters. Nos. 1-6 are all plate-like and of much the same thickness as shown in the middle transverse section figure 20. The two elements shown in figure 7, 7a are probably a terminal pair that was seated on the proximal caudal or cervi- cal region, as indicated by the broad flat front edge which formed a contact and the free thinner posterior edge which appears to end [if not begin] the series abruptly. But the ani- mal to which these odd bones belonged may not even have been of the same species as that to which the scales of figures 1-6 belong and form the type. It is pretty clear that the form before us is allied to the Stegosauridee and is possibly included in the Ankylosauridee of Brown* represented by Dinosaurs with large shields and a quite rigid turtle-like back from the Judith River beds near Gilbert Creek, 120 miles north of Miles City, Montana. The closest relationship within the family Ankylosauride so far as the derinal armature affords comparison is afforded by Polacanthus as restored by Nopesa and now on exhibition in the British Museum at South Kensington. As there restored there are first free plates and then a more or less perfectly developed carapace only extended as such over the lumbar and hip region. From the fact that we see the large scales shown in figure 6 so completely fused a lumbar-hip carapace may be supposed present in the Niobrara form. but in the latter there is plainly indicated by heavy sulci the presence of a system of horn- shields at least as large as the keeled plates. These characters evidently form a sufficient generic distinction. It thus seems probable that the Dinosaurs actually paralleled the turtles in the development of keels of dermogene bones enclosed by horny shields and coming near to the formation of a true carapace with a clearly aligned bone and_hornshield system primarily comparable to that of Dermochelys asit now exists. Jt is not to be forgotten, however, that the unusual structure of the Archelon carapace described in previous pages makes it very likely that ere long a turtle may be found with a neural, pleural and marginal series greatly reduced and mainly replaced by rows of large shields not greatly unlike those now described. Yale University Museum, New Haven, Conn. * The Ankylosauride, a new family of Armored Dinosaurs from the Upper Cretaceous ; by Barnum Brown. Bull. Amer. Mus. Nat. Hist., vol. xxiv, Art. XII, pp. 187-201, New York, Feb. 13.1908. [Though I fail to see why the Nodosauride of Marsh are ignored in this paper. | Wolcott Gibbs. 9538 WOLCOTT GIBBS. Wotcorr Gipps, for many years an associate editor of this Journal, and during the last part of his scientific career the most commanding figure in American chemistry, was born in New York, February 21, 1822. “His father, Colonel George Gibbs, was one of the earliest American mineralogists, and is commemorated in the mineral Gibbsite. He was a friend of the elder Silliman, and his fine collection, deposited in New Haven in 1812 and purchased in 1825, became the foundation of the mineral cabinet of Yale College. His mother, Laura Wolcott Gibbs, was the daughter of Oliver Wolcott, Secretary of the Treasury during part of the administrations of Wash- ington and John Adams, and granddaughter of the signer of the Declaration of Independence of the same name. The child, who was the second son, was named Oliver Wolcott Gibbs, but, as he disliked the name of Oliver, he dropped it in early life, and is known to the scientific world as Wolcott Gibbs. The taste for science inherited from his father was not slow in appearing, for, as he tells us, even in his early childhood, which was passed mostly at his father’s large estate called Sunswick on Long Island a few miles from New York, ‘“ he was often occupied with making volcanoes with such materials as he could obtain, and in searching the stone walls on the estate for minerals and the gardens and fields for flowers.” At the age of seven he went to live with William Ellery Channing, the great Unitarian divine, who had married his aunt, but he was under the special care of another aunt, Miss Sarah Gibbs. The winters were passed in a fine house on Mt. Vernon street, Boston, and the summers at Oakland, a beauti- ful estate about five miles from Newport, R. I. The fame of Dr. Channing brought many foreign visitors, especially in sum- mer, and this stimulating mental atmosphere, to which the boy was exposed for five years, had a marked effect on his intellectual development. In 1837 he entered Columbia College, and his first original work dates from his junior year there. It consisted of a new 954 Wolcott Gibbs. form of galvanic battery, in which carbon was used for the first time as the inactive plate. Upon receiving his degree of A.B. in 1841 he began his chemical education by taking a place as assistant with Dr. Robert Hare, professor of chemis- try in the Medical School of the University of Pennsylvania. His long life, therefore, linked one of our earliest chemists with those of the present generation. After some months in this laboratory he entered the College of Physicians and Sur- geons of New York with the intention of qualifying himself to hold the chair of chemistry in a medical school. It is cer- tainly remarkable that at this early day he should have been able to work out so well-conceived a plan for chemical study ; which he continued, after taking the degree of M.D. in 1845 and incidentally the A.M. in 1844, by going to Europe, where he entered the laboratory of Rammelsberg at Berlin. Some months here were followed by a year under Heinrich Rose, also in Berlin, a semester in Giessen with Liebig, and courses of lectures in Paris from Laurent Dumas and Regnault. Of this brilliant constellation of teachers, Heinrich Rose had by far the most influence on him, as is shown by his lifelong devotion to inorganic and analytical chemistry in spite of the fascinations of organic chemistry under Liebig and physical chemistry under Regnault. He always spoke of Rose with the greatest admiration and affection, and evidently regarded him as his chemical father. In 1848 he returned to New York, fae after giving a short course of lectures at Delaware College, Newark, was elected in 1849 professor of chemistry and physics in the newly created Free Academy now ealled the College of the City of New York. For the next eight years there is little to record except his marriage to Josephine Mauran in 1853, and the fact that in 1851 he began a series of reports on chemical and physical progress for this Journal as associate editor, continued till 1873, which form 500 pages of suecinet but clear and comprehensive abstracts of the most important papers of this period. He also carried on a similar work for American chemistry as corre- spondent of the German Chemical Society from 1869-1877. Until 1857 his papers, few in number and of no great import- ance, only show he was. finding his feet, but m that year Wolcott Gibbs. 955 appeared the account of his great investigation of the ammonia- cobalt compounds with F. A. Genth, which contained so full and thorough a study of the principal series of these puzzling bodies that very little in the way of experiment was left for future work, the analytical and chemical work being supple- mented in many cases by crystallographic determinations by J. D. Dana. So exhaustive a research was a new thing in American chemistry, and at once established his reputation on a firm basis. In 1861 appeared the first of three papers on new methods of separating the platinum metals, an important research on a most difficult subject, which was a worthy companion of his great work on the ammonia-cobalt compounds. These investi- gations led to his election in 1863 to the Rumford Professor- ship of the Application of Science to the Useful Arts in Harvard University, left vacant by the retirement of Professor E. N. Horsford, and accordingly, after he had established himself in Cambridge, he took charge of the chemical labora- tory of the Lawrence Scientitie School. The number of his students was smali, but more were not to be expected or desired, as the object of the course was to educate professional chemists, and the supply was somewhat greater than the demand. His own work during this period is described in a number of short papers principally on chemical analysis; the most conspicuous of which, introducing the electrical deposi- ‘tion of the metals asa means of their quantitative determina- tion, laid the foundation of what has since become a new department of the science—electrical analysis. Another of these papers on the sand or glass filter is interesting as a fore- runner of the Gooch crucible, and his experimental method for correcting the volumes of gases may also be mentioned. In 1871 a reorganization of the Chemical Department con- solidated the laboratory of the Lawrence Scientific School with that of Harvard College, and relegated Dr. Gibbs to the Department of Physics, where he taught a small advanced class in Light and Heat. Some papers on optical subjects inspired by the discovery of the spectroscope probably led to this assignment, which was justified on the score of economy, but its wisdom may be doubted, as it deprived the chemical 256 Wolcott Gibbs. students of the university of the teaching of the best chemist in the country, and diminished the volume of his original work, since up to a certain point the amount of chemical pro- duction is directly proportional to the number of hands at the disposal of the master. Yet a study of his papers shows that, when his time was occupied by the administration of a labora-— tory and more elementary teaching, he did not produce those extended researches on which his fame principally rests, as these date from the earlier and later periods, when his whole energy was concentrated on work of his own with, in the later period, one skilled private assistant. His two earlier investigations of this sort had to do with subjects so abstruse and difficult that most chemists would have shuddered at the idea of attacking them, but, as he once said, he was a pioneer, and seemed to enjoy iothing more on breaking a way through these tangled jungles on the frontier of the science. Accordingly he next took up a field of work— the complex acids of tungsten and molybdenum—even more terrible, for here it takes courage merely to read his papers, and follow his footsteps through the bewildering maze of series after series of compounds. What then must it have been to find the necessary clue to this labyrinth, and to estab- lish the nature of these numerous compounds? Especially since in doing this it was necessary for him to work out some of the most difficult problems of analytical chemistry, as the separation of many of the elements involved had never been attempted before. In this great investigation over fifty new series of compounds were discovered by him, and the old series fully investigated and put on a solid foundation. The first paper appeared in 1877, and the last in 1896, this being the last paper published by him. The invention of the ring burner, his most important con- tribution to the apparatus of analytical chemistry, dates from 1873, just after his transfer to the Department of Physics; and his porous diaphragms for heating precipitates in gases were described in the same year. In 1877 appeared his excellent method for preparing nitrogen. In 1887 he became professor emeritus, and retired to New- port, where he continued his work on the complex acids in a Wolcott Gibbs. 957 laboratory which he built for the purpose; and also invaded the only remaining department of inorganic chemistry, which could be ranked for complexity and difficulty with the three already occupied by him,—this was the cerium group, but advancing years prevented him from making more than a pre- liminary exploration in this field. In these last years at Newport he also took up an extended study of the effect of isomeric organic compounds on animals, at first with Dr. H. A. Hare and later with Dr. E. T. Reichert. In addition to this work in physiological chemistry he had in his earlier papers made occasional excursions into theoretical chemistry, organic chemistry, mineralogy, and physics, an astonishingly broad field to be covered by one man. His fame, however, rests on his work in inorganic and analytical chem- istry, and it seems to me that his two qualities, which make this préeminent, are thoroughness and accuracy. Next to these I should place his wonderful suggestiveness. His ideas flowed rather in a torrent than a stream, and occasionally bore him away from some good subject, after he had little more than broken the ground in it. Even old age did not check this current, his paper on the cerium metals published at 72 containing five new and ingenious suggestions for their sepa- ration. The criticism, which might be made on his work, is that he was content to prepare the experimental foundations, but left it to others to build the theoretical structures upon them. The reason for this, I think, was that before all else he was an experimentalist. His table was always covered with a multitude of test tubes each with a label in its mouth setting forth the substances reacting within, and it was beautiful to watch the sharpness of insight with which he seized on the favorable indications in these numerous experiments, and the rare skill and robust energy with which he followed any line of work that promised results of value. As a teacher he had an especial faculty for imbuing his stu- dents with the enthusiasm and spirit of original work; and they felt the greatest admiration and affection for him. The only instruction I received from him was a single voluntary lecture in mysenior year. In this his ideas came hurrying out with an impetuous speed, as if there were too many to be 258 Wolcott Gibbs. forced into the narrow limits of an hour. The effect was wonderfully inspiring, when, as in this case, one did not have to take notes. As already stated, his teaching was confined to a few students, and it isa matter of regret that more did not have the opportunity of profiting by contact with this great mind. Of the various societies, to which he belonged, he was most warmly attached to the National Academy of Sciences. He was one of its founders in 1870, and at his death the last sur- vivor of the original members. He served it as foreign secre- tary, vice president, and from 1895 to 1901 president. He was also a member of the American Academy of Arts and Sciences and of the American Association for the Advance- ment of Science, of which he was a vice president in 1866, president in 1897. In addition to these his achievements brought him honorary membership in the Philosophical Soci- ety of Philadelphia, and the American, English, and German Chemical Societies, and corresponding membership in the British Association for the Advancement of Science, and the Royal Prussian Academy. The most striking of these appre- ciations of his merit was his election as honorary member of the German Chemical Society, as he was the only American on this list. Phe degree of LL.D: -was conferred on) hammay, Columbia University, Harvard University, the University of Pennsylvania am absentia as a special honor, and the Colum- bian University of Washington. During the Civil War he proved himself a public spirited, patriotic citizen, devoting a large part of his time to service on the executive committee of the Sanitary Commission. The frequent meetings of this body suggested to him the idea of “a elub which should be devoted to the social organization of sentiments of loyalty to the Union.” warp C. PickEertne, Director. Pp. 213-288. Vol. LIX, No. II. Photographic Photometry on a Uniform Seale ; by Epwarp S. Kine. Pp. 33-62,°6 figures. Vol. LX, No. IX. A Catalogue of Photographic Charts of the Sky. Pp. 231-251. Vol. LXIV, No. I. Observations with the Meridien Photo- meter during the years 1902 to 1906. Pp. 32: No: Uf. ..The Variable Star SS Cygni. 213843 ; by LzEon Campsetu. Pp. 33-53. I Plate. No. HI. Schénfeld’s Comparison Stars for Variables. Pp. 55-89. CircuLars.—No. 137. 25 New Variable Stars in Harvard Map, Nos. 31-43. No. 138. 060547. The Variable Star, 31,1907. Pp. 6. No. 139. 26°179. A New Variable of the Class of B Lyre. No. 140. 16 New Variable Stars in Harvard Map, Nos. 4 and No. 141. 29 New Variable Stars near Nova Sagittarii. Pp. 4. 28 New Variable Stars in Harvard Map, Nos. 30 and 270 Scrientyjte Intelligence. 4. Publications of the Allegheny Observatory of the Unt- versity of Pittsburgh.—YVhe following have recently appeared : Vol. I, No. 6. The determination of the orbit’ of a spectro- scopic binary by the method of least squares ; by Franx Scurzs- INGER. Pp. 33-44. No. 7. The orbit of 6 Aguile; by Roserr H. Baker, Pp. 45-66. No.9. A partly graphical method for predicting solar eclipses; by FRaNK ScHLESINGER. Pp. 57-64. 5. Washburn Observatory of the University of Wisconsin, GEORGE C. Comstock, Director.—The following volume has been recently issued : Vol. XII. Determinations of Proper Motion, 1902-1907. Part I. Proper Motions of Faint Stars; by GrorcE 0. CoMSTOCK, Director. Pp:*317.> Whe observations here given have been made with the 40 cm. equatorial of the Washburn Observatory; to a considerable extent they repeat, after a period of more than fifty years, the measurements made by Struve at Pulkova, on stars fainter than the ninth magnitude. 6. A Treatise on Spherical Astronomy, by Sir Ropert Bee Cambridge, 1908 (The University Press)—The present trea tise by Sir Robert Ball, the distinguished Lowndean -Professor of Astronomy at Cambridge University, covers quite an amount of ground not included in the classical works of Briinnow, Chauve- net and later writers and thus seems a valuable addition to our text-books. Thus it gives a glimpse into the theory of map making and into the rudiments of theoretical astronomy besides the usual applications of spherical trigonometry to celestial prob- lems. An interesting feature are the numerous exercises, though some of these seem more atest of algebraic ingenuity than of astronomical insight. Among the novelties of the book may be cited the nomenclature “nole” and “anti-nole” for the poles of a great circle, corresponding to the North and South Poles ; to us it hardly seems that there was a crying need for further designations, also, perhaps, the similarity to “node” is unfor- tunate. The presentation, as is usual with Sir Robert Ball, combines great lucidity and directness and we may again add our best wishes for the adoption of the work for class and private study. Wiles 7. Bulletin of the Mount Weather Observatory, Wittiam J. Humpureys, Director.—Prepared under the direction of W1ILLIs L. Moorz, Chief U. S. Weather Bureau. Vol. I. Part 4, pp. 207-77 ; 3 charts, 3 figures.—This number contains the following articles: Pyrheliometer and polarimeter observations, by H. H. Kimball ; recent auroral displays and magnetic disturbances, by W.R. Gregg ; magnetic declination, by E. R. Miller ; upper air temperatures for April, May and June, with charts of upper air isotherms, by W. R. Blair. Miscellaneous Intelligence. 271 8. National Antarctic Expedition, 1901-1904, Album of Photographs and Sketches with a Portfolio of Panoramic Views. Pp. 303, 4to; 165 plates and 2 maps. London, 1908. (Pub- lished by the Royal Society and sold by Harrison & Sons, St. Martin’s Lane, W. C., and Oliver & Boyd, Tweeddale Court, Edinburgh.)—The two volumes giving the results of the meteor- ological and physical observations made by the National Antarctic Expedition were noticed in the December number (p. 588). We have now an additional volume presenting in most attractive form views of the life and scenery of the region visited. The photographic work was in charge of Lt. Skelton, and most of the admirable views here reproduced were taken by him; the name of L. C. Bernacchi is also frequently associated with his. The volume and accompanying portfolio contain 165 plates, of which 128 are from photographs. The hfe of the southern ocean is well shown in the interesting series of photographs of the Adélie and Emperor penguins, also of the seals, whales and albatross. The scenic views present a vivid impression of the striking features of the land and ice of the Antarctic, particularly of its capes and lofty mountains. Especial interest attaches to the photographs of the Great Ice Barrier, the abrupt cliffs of which ex- tend for many miles from King Edward VII Land to Ross island. The height is as great as 280 feet at some points, and the surface comes down at others to within 18 feet of the water level. This Great Barrier sheet moves northward at the rate of 45 yards per month, but in consequence of its recession by breaking up the sea face is now some 10 to 15 miles farther south than sixty years ago. A special portfolio contains an interesting series of sketches, largely panoramic, due to the artistic work of the Junior Sur- geon, Edward A. Wilson. 9. The Chemical Constitution of the Proteins; by R. H. AvERS PuimuerR, D.Sc. In two parts. Part I, pp. xi+100; Part Il, pp. xi+66. London and New York, 1908 (Longmans, Green and Co.).—The development of biochemistry as a sepa- rate department of study has been so rapid and fruitful that the entire field is already too large for exhaustive treatment in a single volume. The unique importance of the proteins has always made them favorite subjects for investigation. In recent years particularly, the literature on these compounds has increased to an extent that makes timely an exhaustive compilation like Dr. Plimmer’s. The monographs are concerned with the chem- ical composition of the protein molecule and the chemical charac- teristics of its component units, rather than with the behavior of individual protein substances. The organic chemist as well as the physiologist will have occasion to consult such a review, in considering the historic development of the study of the amino- acids as well as the interesting attempts at the synthesis of com- plex protein-like compounds (with which Part IL especially deals). In accord with the intent of this series of monographs, an extensive bibliography is published in each part. Eo Bae iw) —I Sccentafic Intelligence. 10. Standard Algebra ; by Witt1am J. Misia New York State Normal College, Albany, N. Y. Half leather, 12mo, 464 pages. New York, 1908 (American Book Company). —This use- ful text-book follows the method of the Inductive Algebra pub- lished in 1881 by the same author. ‘The new ideas that have been brought into the teaching of elementary algebra in the interval are presented, such as the remainder theorem for purposes of factoring, and the graph, which 1s used for illustration to a limited degree. It is a handy volume, bound and trimmed to carry in the pocket, and the exercises are numerous, fresh and va chosen. Ww. ll. Kraft, dkonomische, technische und ieicttubnckchee Tee Studien tiber die Machtentfaliung der Staaten; von EK. Reyxr. 8°, pp. 880, many diagrams intext. Leipzig, 1908.—The work of Professor Reyer, who is well known for his studies in theoretical geology, has always been characterized by great originality, both in his views and in his mode of presenting them. He has also been widely interested in matters humanistic, and it is, there- fore, not strange to find a volume coming from his pen which relates to subjects outside of his especial field, The volume before us is a conspectus of the economic develop- ment of the chief nations in matters relating to their main indus- tries, those upon which their material prosperity depends. Such comprise iron and steel, coal, precious metals, manufactures, commerce on land and sea, agriculture, and a great variety of others in which power is an element of first importance. The history of the growth of power, its various sources of supply, its relation to the topics mentioned above, and its future are thought- fully treated. The book is illustrated by many diagrams and, written in a clear and well-poised manner, it presents an interest- ing and popular exposition of a most important subject.. vee 12. International Congress of Applied Chemistry.—The seventh International Congress of Applied Chemistry will be held in London from May 27 to June 2. The Honorary Secretary is William Macnab, address 10 Cromwell Crescent, S.W. The Science Year Book, with Astronomical, Physical and Chemical Tables ; Summary of Progress in Science, Directory, Biographies and Diary, for 1909 (fifth year). Edited by Major B. F. S. Baden-Powell. Portrait of Sir William Ramsay as frontispiece. Pp. 148+38655. London (King, Sell & Olding, 27 Chancery Lane, W.C.) OBITUARY. Proressor Harry G. Seg ey, the well-known English geolo- gist and vertebrate paleontologist, died on January 8, in his seventieth year. New Circulars. \ 84: Eighth Mineral List: A descriptive list of new arrivals, rare and showy minerals. 85: Minerals for Sale by Weight: Price list of minerals for blowpipe and laboratory work. 86: Minerals and Rocks for Working Collections: List of common minerals and rocks for study specimens; prices from 1% cents up. Catalogue 26: Biological Supplies: New illustrated price list of material for dissection; study and display specimens; special dissections; models, etc. Srxth edition. Any or all of the above lists will _be sent free on request. We are constantly acquiring new material and publishing new lists. It pays to be on our mailing list. Ward's Natural Science Establishment 76-104 CotniecE AVE., Rocusstser, N. Y. Warns Natura Science EsTaBtisHMent A Supply-House for Scientific Material. Founded 1862. Incorporated 1890. DEPARTMENTS: Geology, including Phenomenal and Physiographice. Mineralogy, including also Rocks, Meteorites, etc. Palaeontology. Archaeology and Ethnology. Invertebrates, including Biology, Conchology, etc. Zoology, including Osteology and Taxidermy. Human Anatomy, including Craniology, Odontology, etc. Models, Plaster Casts and Wall-Charts in all departments. Circulars in any department free on request; address Wards Natural Science Establishment, 76-104 College Ave., Rochester, New York, U. S. A. CONTENTS. Page Art. XIL.—Recent Observations in Atmospheric Electricity; by P.O. Dixee eee ee Se ee 197 XIII.—Iodyrite from Tonopah, Nevada, and Broken Hill, New South Wales ; by E. H. Kraus and C. W. Coox_- 210 XIV.—Deviation of Rays by Prisms; by H. S. Unter.__-- 223 XV.—Heat of Oxidation of Tin, and second paper on the ‘Heat of Combination of Acidic Oxides with Sodium Oxides; by W. G. Mixtep 2220 0 es ee 929 XVI.—Neptunite Crystals from San Benito County, Calli- fornia; by W. Ei HORD. 22. 225s ee 235° mate ; by F. A. Goocn and R. 8. BoswortH ._-.-_---- 241 XVIII.—Doppler Effect in Positive Rays; by J. TRowBripGE 245 XIX.—New Armored Saurian from the Niobrara; by G. R. WELLAND <6 2 As a ce W oLcorTrr GIBBS 22. 220 2 ee ee eee SCIENTIFIC INTELLIGENCE. Chemistry and Physics—New Method of Forming Liquid Alloys of Sodium and Potassium, JAUBERT: Determination of Cerium and other Rare EKarths in Rocks, Dierricu, 260.—Solubility of Metallic Gold in Hydrochlorie Acid in the presence of Organic Substances, AWERKIEW: The Composi- tion of Matter, E. MuLprER, 261.—Introduction to the Rarer Elements, P. KE. Brownine: Feste Lésungen und Isomorphism, G. Bruni: Produc- tion of Helium from Uranium, F. Soppy: Charge and Nature of the a-Particle, E. RUTHERFORD and H. GEIGER: Amount of Water in a Cloud formed by Expansion, W. B. Morton, 262.—Permanent Magnetism of Copper, J. G. Gray and A. D. Ross: United States Magnetic Tables and Magnetic Charts for 1905, L. A. BavEr, 263. i Geology and Natural History—Fossilen Insekten und die Phylogenie der Rezenten Formen, A. HANDLIRSCH, 263.—Connecticut Geological and Natural History Survey, W. N. Rick: Mississippi State Geological Sur- vey, A. F. Criprer, 264.—Interpretation of Topographic Maps, R. D. SALISBURY and W. W. Atwoop: Zonal Belt Hypothesis, a New Explana- tion of the Causes of the Ice Age, J. T. WHEELER: Handbuch der Min- eralogie, C. Hintzzk: Chemische Krystallographie, P. GrotH, 265.—Notes of a Botanist on the Amazon and Andes, R. Spruck, 266. Miscellaneous Scientific Intelligence—Carnegie Institution of Washington. Year Book No. 7, 1908, 267.—Report of the Librarian of Congress and Report of the Superintendent of the Library Buildings and Grounds, H. Putnam: Harvard College Observatory, E. C. Prckerine, 269.—Publica- tions of the Allegheny Observatory of the University of Pittsburgh : Washburn Observatory of the University of Wisconsin, G. C. COMSTOCK : Treatise on Spherical Astronomy, R. Batu: Bulletin of the Mount Weather Observatory, W. J. HumpHreys, 270.—National Antarctic Expe- dition, 1901-1904: Chemical Constitution of the Proteins, R. H. ADERS PurmMerR, 271.—Standard Algebra, W. J. Mitne: Kraft, dkonomische, technische und kulturgeschichtliche Studien tiber die Machtentfaltung der Staaten, E. Reyer: International Congress of Applied Chemistry : The Science Year Book, 272. Obituary—H. G. SEELEY, 272. XVII.—Gravimetric Determination of Silver as the Chro- r. Cyrus Adler, is fies a a OS" 9 Librarian U. S. Nat. Museum. MOL XX VII. 2 APRIL, 1909. Established by BENJAMIN SILLIMAN in 1818. AMEHRICAN JOURNAL OF SCIENCE. Epiron: EDWARD S. DANA. 4 , ASSOCIATE EDITORS i Proressorns GEORGE L. GOODALE, JOHN TROWBRIDGE, é W. G. FARLOW anv WM. M. DAVIS, or Camsriocz, - 4 Proressors ADDISON E. VERRILL, HORACE L. WELLS, L. V. PIRSSON anp H. E. GREGORY, or New Haven, Proressor GEORGE F. BARKER, or PHILADELPH, Proressor HENRY S. WILLIAMS, or ItTHaca, Proressor JOSEPH S. AMES, or Battimore, Mr. J. S. DILLER, or Wasurinerton. FOURTH SERIES No. 160—APRIL, 1909. VOL. XXVII—[W HOLE NUMBER, CLXXVII] NEW HAVEN, CONNEOCTICBT WO, a , {yf Ona! ar weak, brief duration. 7.24 A. M. : Jan. 5,—12.10 noon— sec., strong ; several weak shocks two to three minutes later. 5.05 P. M. W510) IPs HVT Jan. 6,— 9.00 aA. M. 10.00 A. M. unimportant. unimportant. Fig. 9. Fic. 9. The Maurolico Monument in the Villa Mazzini; this has fallen due S.W. Jan. 7,— 5.00 a, M.—strong, brief duration. 6.28 Pp. M—5 sec., strong, threw down walls, followed by a replica. Several shocks during the night and the early morning of Jan. 8th. This should not be taken as a complete record of all shocks occurring during the time nor can the relative intensity be depended upon as accurate, the various observations having been made on shore, on shipboard and in the ruins. The need of a good, portable seismograph was never better illustrated than by this event, as all the instruments in the neighbourhood were destroyed. It would have been possible to take a portable F. A. Perret—Report on the Messina Earthquake. 331 instrument down to Messina from Naples and to have thus obtained a complete record of all after-shocks. Of those indicated above three are deserving of special mention. That of Jan. 2, at 9.40 P. m., occurred when the writer was standing on the deck of a steamer moored to the embank- ment. The impression was that of a submarine explosion—a loud report and a sharp vertical movement. These, however, Fie. 10. Fie. 10. Tall stack ; top snapped off and fallen 8.S.W. were partly due to the iron hull of the ship receiving the impact from the water. In from three to five seconds was heard the crash of falling walls within the city and smouldering fires blazed up anew. ‘This shock is reported to have snapped the anchor tips of the British cruiser “ Exmouth,’ which was earried two miles to the southward by a twelve-knot current through the Straits. At ten minutes past noon of the 5th another strong shock of the same general nature occurred, but this was felt on shore 332 FL. A. Perret—feport on the Messina Larthquake. only as a horizontal wave motion. It was followed by several weaker movements. | At 6.28 p.m. of Jan. 7, a shock lasting fully five seconds formed the most interesting of those observed. The duration was such as to give ample time to study the phenomenon and it was impossible to avoid the conviction that the originating movement at the centrum had a duration not greatly inferior to that of the observed effect. This is contrary to the accepted ideas of the day regarding earthquake generation and a dis- cussion of the subject may be reserved for a future paper, but EerG lal Fie. 11. Fronts fallen from houses, lying East and West. the writer feels in duty bound to record the impression in the belief that no honest observation is without value. This shock was experienced when on board the U.S8.S. “Scorpion” and the man on watch reported having “seen” the earthquake pass through the city from N. toS. When interrogated he could give no more definite information, but it is evident that the earth waves had produced a visible undulation of the buildings and walls along the water front. Many walls fell and the shock was followed by another not as strong. A number of shocks occurred during the night and in the early morning of the 8th. As to the cause of these Calabrian earthquakes, the writer inclines to the opinion of Mercalli, viz.: that they are due to the movements of deep-seated magma and belong, therefore, I A. Perret—Report on the Messina Harthquake. 333 to the type which he denominates “inter-voleanic.” In their nature they are, of course, tectonic, and I often permit myself to ask if the primal cause of all tectonic earthquakes may not yet be found in magmatic intrusion, the fact of their non- occurrence in the immediate neighborhood of active volcanic vents and of their prevalence in the steeply folded portions of the earth’s surface constituting, in my opinion, an argument for, and not against, the hypothesis. TEN ee 1) Fie. 12. North end of Quay. At all events, this portion of the Italian peninsula lying, as it does, between the Tyrrhenian and Ionian deeps and subject to the upheaval revealed by the Quaternary terraces of the Aspromonte, must be considered as one of the most pro- nouncedly seismie¢ areas of the globe. ‘This being the case, it is idle and harmful to encourage the hope that this region will not be subject in the future, as it has been in the past, to frequent and severe earthquakes. Rather should it be impressed upon both government and people that, sooner or later, these are certain to occur and that the proper ‘construction of houses to withstand their effects is an absolute necessity. Only thus, with the active prosecution of the study of prediction, may we 834 4H. A. Perret——Report on the Messina Harthquake. hope to avoid future repetitions of the recent great disaster, and ample means should, therefore, be provided for putting earth-science on a world-wide basis and bringing it thus to at Fie. 13. Wie. 13. Wreck of a tall, poorly constructed building. least a par with astronomy. A glance at a list of the voleanic and seismic catastrophes of the last eighteen years will suttice to show that few other lines of scientific investigation ean vie with this in importance to the human race. Vomero, Naples, Italy. Maury— Connecting Link in the Genesis of Fulqur. 335 Art. XXVII.—A Wew Connecting Link wm the Genesis of flulgur ; by Cartorra J: Maury. Amone a quantity of fossils lately collected by Professor G. D. Harris at Montgomery, Louisiana, from the Jackson horizon of the Eocene is a very interesting species which forms a perfect connecting link between Levifusus and Fulgur. A dozen specimens were found. The relationship of the two genera was pointed out some years ago by Dr. Dali and Professor Harris. Dr. Dall in 1890 stated that Mudgur, which took its rise in the Eocene, was descended from such forms as Levifusus Blakes and tr abeutus. Professor Harris later noted the tendency shown by many Levifusi to revert to an ancestral Plewrotoma-like form and traced the derivation of Mulgur from Pleurotoma through Sureula, Levifusus (pagoda-like forms), Levifusus (suteri- like forms), Levifusus (trabeatus-like forms), Levifusus Branneri to Pulqur echinatum. But Levifusus Branneri Harris in addi- tion to shoulder spines is ornamented by a row of twelve nodules on the center of the body whorl. The Montgomery shell is without the shghtest trace of this row, and, as shown in the accompanying figure, presents such a striking resemblance to Fulgur that it might almost be taken as Levifusus fulguriparens one of the many varietal forms of TONGUT 3 (oneitude 25") spiniger. The spire, however, is almost exactly that of Levifusus Brannert. To emphasize the fact that it is the most direct ancestor of Hulgur known, the name Julguriparens has been given to the Montgomery shell. Hastings-on-Hudson, N. Y. 336 Scventific Intelligence. SCIENTIFIC INTELLIGENCE. I. CnyeEmistry AND Puysics. 1. A Method for Calculating the Boiling-points of Metals.— The view was advanced by F. Krarrr about four years ago that the essential process of boiling in a vacuum consists in overcom- ing gravity, and that this, on the surface of the earth, is equiva- lent to the atmospheric pressure. As a proof of this fact he showed that the elements mercury, cadmium, zinc, potassium, sodium, bismuth and silver require just the same addition of heat to bring them from the point of the commencement of volatiliza- tion in a vacuum to the point of boiling in a vacuum, as is required to bring them from the latter point to the point of boil-. ing under atmospheric pressure. In order to obtain further data in regard to this interesting relation, Krarrr and KnocksE have determined the data under consideration for arsenic, and have found : Commencement of evaporation, 0™™_ 2-2 522-2 - 2 9Ge Siblimes tat 0 ese ee 325° Sublimes:at76000 222 oe ee ee Ditlerence in eachscasey 52 3-2 ee 229° They found with thallium : Commencement of evaporation, 0™™ __.__--.-.--- 174° Boiling-pomb at ON yes ee ae ee Se ee tee Since the difference here is 644°, the calculated boiling point at 760™™ is 1462°. In this manner, from data furnished by Krafft and his co-workers, Moissan calculated the approximate boiling point of copper as 2240° and of gold as 2530°, and he found by distilling in an electric furnace an alloy consisting of equal parts of copper and gold, that the copper boiled off faster than the gold, thus showing a lower boiling point of the copper, as indi- cated by the caleulation.— Berichte, xlii, 202. He awe 2. Some Properties of the Radiun. Emanation.—About two years ago RutuERForp observed that the emanations of radium, actinium, and thorium were completely absorbed by cocoanut charcoal at ordinary temperatures. He has recently repeated. this experiment with the radium emanation, using much larger quantities, and has found that the actual volume of this emanation capable of absorption at room temperatures is very small. For example, several grams of the charcoal are required to absorb completely the emanation from 200 mg. of radium at ordinary temperature, although the volume of the gas is only one-tenth of a cubic millimeter. As was to be expected, the absorptive power of the charcoal increases rapidly with the lowering of the temperature. It was found that 0°8g. of charcoal from which Chemistry and Physties. 337 air had been removed by heating absorbed the emanation from 83 mg. of radium (about 0:05 cubic mm.) at —150°C. As the temperature was slowly raised, less than one-tenth of the absorbed emanation could be pumped out at —50° C., as was shown by measurement by the y-ray method. Above —40° C. the emanation commenced to escape rapidly, and half had been pumped off at 10°C. About 10 per cent remained at 100° C., but practically all was released at the temperature of the softening of glass. The results show that at 10° C. the charcoal absorbs about 0:03 cubic mm, per gram, and at —40° C. about 0:06 cubic mm per gram.— Chem. News, xcix, 76. PBee ties We 3. Method for Preparing Hydrogen Phosphide.—MatiaNon and Trannoy have devised a simplified method for the prepara- tion of the gas PH,. They mix powdered calcium phosphate which has been previously calcined, in order to remove every trace of moisture with powdered aluminium, in the proportions required by the equation 3Ca,(PO,),+8Al, = 3Ca,P,+8Al,0, put the mixture in a crucible, heat it to dull redness, and ignite it with an ignition mixture according to the Goldschmidt method. The products of the reduction do not separate, but form a brownish mixture, which after being broken up is suitable for the produc- tion of hydrogen phosphide. by the action of water, followed by hydrochloric acid towards the end of the operation. The result- ing gas was found to contain 2 or 3 per cent. of hydrogen, but otherwise it appeared to be perfectly pure.— Comptes Rendus, exlvilil, 167. Ex We 4. The Theory of Valency, by J. NEwton FrRienp. 12mo, pp. 180. London, 1909 (Longmans, Green and Co.).—This work is one of a series of text-books of Physical Chemistry, edited by Sir William Ramsay. Nine of these monographs have already appeared, and five more are announced as in the course of preparation. The book under consideration gives a concise account of the more important theories of chemical combinations which have exercised the minds of scientific men down to the present day. It appears that heretofore there has been no treatise in the English language upon the important subject of valency, while in German there is only one, a not very exhaustive work which was published several years ago. The book will be useful to students of chemical theory, since it covers the ground very thoroughly and gives a’ very full list of references to the literature. Eye We 5. Recent Advances in Organic Chemistry, by A. W. STEWART. 8vo, pp. xv, 296. London, 1908 (Longmans, Green and Co.).—The author has endeavored to give an idea of some of the most recent researches in organic chemistry which have been carried out within the last ten years. The subject has been con- sidered from a synthetic point of view and the work has some commendable features, but is too condensed to be of much value Am. Jour. Sct.—FourtH Series, Vout. X XVII, No. 160.—Aprit, 1909. 23 338 Scientific Intelligence. to one who is familiar with the advances made in recent years. While many important researches unfortunately have not been considered, nevertheless the subject has been treated in such a - manner that the book will tend to stimulate the enthusiasm of students of organic chemistry. TB ads 6. Michelsonw’s Ether Research.—Emit Kout, after a close scrutiny of Michelson’s celebrated experiment, concludes that a careful study of the formation of the interference lines which are the essential feature of this experiment is necessary before a con- clusion can be reached in regard to the negative results. He calls attention to the importance of the factor of the distance; and discusses the questions which arise if ordinary light is employed instead of monochromatic, and recommends that the experiments should be repeated with attention to these points.—Ann. der Physik, No. 2, 1909, pp. 259-307. Jy 7. Influence of Pressure upon Thermoelectric Horce.—Hxin- ricH HoOrie employed a pressure of 1400 kg/cm” and found that the thermoelectric force of a platinum mercury combination, which before pressure at At = 150°, gave an electromotive force of 10~-° volt per degree increase of temperature. When this thermo-element was submitted under the same conditions of tem- perature to a pressure—it gave for kg/cm~ a change per degree Aé of 2°18:10-” volt. The current direction of this pressure effect was opposed to tbe original thermoelectric effect, and up to a pressure of 1400 kg /em~™ no deviation from proportionality with the pressure was observed. Similar results were obtained with a eutectic KNa alloy.— as saa ese 20 grams 20. grams Sul phutic ss a es eres 2 is 1°5 a8 SOdium| peroxides.) = 2s: 25 a 15 = Water equivalent of system_- 4,018 ss 4,090 Temperature interval ._-_---- 3°418° 2°658° MeatcObsenVve dene =e 13,733° 10,871° ‘“‘ of oxidation of sulphur 16, 542° --7,906° ce 66 ce (5 iron tie ” 48° == ASE <<“ oxygen evolved =-:. + 151° + 260° 3,294° 3,177° For 1 gram of lead dioxide.. 165° ee The mean is 162° for 1 gram of lead dioxide and for 238-9 grams it is 38,700°, which agrees well with the result of experi- a2 (On line (Oy Ala aye) Mixter— Heat of Formation of Titanium Dioxide. 397 ment 1. The fusion of 2 when treated with hot water left lead oxide and but little dioxide, while in 38, where less sodium peroxide was used, considerable lead dioxide remained. These facts indicate that the lead dioxide which separates on the hydrolysis of sodium plumbate is reduced to oxide by sodium peroxide in the presence of water. The following results support this view: a mixture of the two oxides was placed in cold water and the whole was heated. The solution contained lead, but gave no chlorine after adding hydrochloric acid and warming. A fusion of equal parts of lead and sodium per- oxide left, after exhausting with water, lead dioxide, while when two parts sodium peroxide were taken the insoluble residue was brownish yellow and contained but little lead dioxide. The heat of hydrolysis of sodium plumbate is derived as fol- lows : _ Na,O.PbO,+ Aq = 2(Na.0O.H.Aq) + PbO, — Na,.0.Pb0O,— H,.O 15,500° = 223,600 = 13900 ‘68,400 Since the PbO, is in the solid state before and after the hydrolysis of the plumbate, it makes no difference in the ther- mal result if it first combines with water and is finally dehy- ‘drated. The hydrolysis as given above is only complete ina large volume of water, since sodium plumbate is soluble as such in a concentrated solution of sodium hydroxide. Zirconium Dioxide. Two experiments were made with mixtures of zirconium dioxide, sodium peroxide, and sulphur. The fusions were not good, and the residues remaining after treatment with hot water set free chlorine from hydrochloric acid, indicating the presence of a peroxide. The results were 251° ‘and 268° for 1 gram of zirconium dioxide, mean 258° and for 122-7 grams 31,700°. If the dioxide was all oxidized to trioxide 19,400° are to be added, giving 51,100°. The only interpretation to be given to the result is that the heat of ZrO, or ZrO,+Na,O is small. Ceric Oxide. But one experiment was made with ceric oxide with the result of 94.6° for 1 gram and 16,300° for 172 grams. The fusion was placed in cold water and after gas ceased to come off the solution was decanted. When the insoluble residue was treated with hot water much gas was evolved—an indication of the presence of a peroxide of cerium. If 2CeQ, is oxidized by sodium peroxide to Ce,O, 9,700° are to be added for the heat of the oxygen taken from sodium peroxide. The thermal result does not indicate combination of sodium oxide with an oxide of cerium. Am. Jour Sct.—FourtTH SERIES, VOL. XXVIL, No. 161.—May, 1909. 27 398 C0. Palache—Note on Crystal Form of Benitoite. Arr. XXXV.--Wote on Crystal Form of Benitoite; by C. PALACHE. Tuer symmetry class to which the erystals of the interesting new mineral benitoite belong could not be definitely established by the forms hitherto observed upon them. Rogers* assigns it to one of two classes, the trigonal-bipyramidal (Class 19 of Groth) or the ditrigonal-bipyramidal (Class 22 of Groth) with probabilities favoring the latter. Neither of these classes has © hitherto had a representative among crystals. Crystals of benitoite recently acquired by the Harvard Mineral Cabinet present a new form which establishes the correctness of Rogers’ assumption of its ditrigonal-bipyramidal symmetry. The form is the second order pyramid (2241); it occurs on all the crystals on the specimen with distinct but small faces which uniformly present a dull luster in striking contrast to that of the trigonal pyramids. The lateral edge between these second order pyramid faces is in most cases truncated by the second order prism with similarly dull faces. These two forms, characteristic for class 22, would appear as trigonal forms in class 195 the fact that when a face of either occurs, others are present of like quality and with six-fold repetition, seems to determine the type positively. Although dull the new faces gave distinct reflections on the goniometer. The average of six excellent readings, 0001 to 2241, was 71° 15’. The average of ten excellent readings, 0001 to 1011, was 40° 12’, a value just half way between those obtained by Rogers (40° 10’) and Landerbach (40° 14’). Calculated from this value @:¢=1:0°7319 and p,='4879. Calculated from this axial ratio the angle 0001 to 2241 is 71° 10’.. The list of forms for benitoite is then as follows: | : Prisms: m (1010), w (0110), DAL20). Pinacoid : ¢ (0001). Trigonal pyramids: p(1011), aw (0111), ¢ (0112). | Second order pyramid: « (2241), The figure shows a typical combination. : Octahedrite, a mineral not before recorded from the benitoite locality, was observed on part of the specimen from which natrolite had been wholly removed by solution in hydrochloric acid. It appears in groups of pale brown crystals, combinations of unit pyramid and base; the crystals are smail and present facetted and curved faces so that they could not be measured but chemical tests showed the presence of titanic oxide alone. Harvard Mineralogical Laboratory, March, 1909. * Science, xxviii, 616, 1908. C. Palache and H. Ek. Merwin—Alamosite. 399 Arr. XXX VI.—Alamosite, anew Lead Silicate from Mexico ; by C. Paracss and H. E. Merwin. Ix this paper is presented the description of a monoclinic lead metasilicate showing in form, habit, and composition close analogies with wollastonite, with which it is regarded as isomor- phous. This mineral was sent to the Harvard Mineralogical Laboratory for identification by the Foote Mineral Co. of Philadelphia, who generously placed at our disposal their whole supply of the material. According to their meager data regarding its occurrence it is found in an undeveloped gold and copper prospect situated near Alamos, Sonora, Mexico. The minerals making up the ore in hand are, however, with trifling exceptions all compounds of lead. The gangne is in part massive white quartz, in part a com- pact gray, brown or black material shown by analysis to con- tain quartz, the new lead silicate and either lmonite or hematite, in varying admixtures. Interspersed through this massive material are occasional vugs lined with quartz crystals and irregular bunches of the lead compounds. Of these the most abundant is cerussite in snow- white aggregates and rare erys- tals. Minute flakes of pale green leadhillite were identified by cleavage, optical character and chemical reactions. Wulfenite is also found, partly in orange-col- ored crystals, more abundantly as a bright yellow stain in all the other minerals of the ore, par- ticularly in the lead silicate. The lead silicate is in radiated fibrous aggregates of more or less pronounced spheroidal form, irregularly interspersed among the minerals already mentioned. It is snow-white in the mass, transparent and colorless in the rare cases where tiny fibers had been free to develop smmgly in open spaces between the spheroids. There is a perfect cleavage transverse to the fibers yielding a curved concentric fracture surface of pearly luster which extends almost uninterruptedly through all the individuals of a spheroid. The few developed crystals that could be secured for study were minute—not more than 0°5™™ in diameter—and the best of them were but poorly adapted to measurement, several fibers being generally adherent in subparallel groups so that it was difficult to secure readings Brest 400 C. Palache and H. EF. Merwin—Alamosite. from individual crystals. The high luster of the mineral, however, made it possible to cbtain readings from the most minute faces and fairly consistent measurements were finally obtained from six crystals. Alamosite is monoclinic, the fibers elongated parallel to the axis of symmetry (crystallographic axis 6). This habit and the minute size of the crystals made it necessary to mount them on the two-cirele goniometer with 010 as pole and the orthodome zone as prism; the measurements and calculated angle§ of the table are, therefore, given for that position, but the symbols and axial ratio are for the normal position. The position was chosen so as to bring out as well as might be, the relation in form to wollastonite. The crystals are simple showing the forms c(001), a(100), 6(010), m(110), v(101), g(011) p21), and 7(121). The ae shows a typical combination in which the forms named, except m and 7, are represented in about their normal development. The relations to wollastonite are shown by the following angles : Alamosite W ollastonite : : Ca 20 ane Oh SO. ene some. Inne 1375 : 1: 0°924 1:053:; 1: 0-967 Angle 001 to 100= B 84° 107 84°30’ 001 to 101 32 02 40 03 e OO1 to O11 42 36 1S} HH ce 100 to 110 53 50 46 21 Table of calculated and observed angles of alamosite, with 010 as pole and 100 as first meridian. Elements for this position : P.=1088; 9,=0°7315 p= ee Elements for normal position: p,=0°672; g,=0°919; w=84 10 Calculated Measured (mean) No. of faces p p p p BAO SEIKO BO Oe 84°10’ 90°00’ 8 a 100, 00700-7907 00 (DX OKO S10) (0X9) 6 56 010 00 00 00 00 00700 2-007 08 6 i NOY 20000236 a0 00 00 36 00 iL UO 2 OCs 30400 Dod) se OmOG 3 Ga Otte S4 A One 2e 84 10 47 29 6 p A21—60 114 3h 57 —60' 12> 31758 9 7 NONE 52 203 eae 52 10 34 18 2 Physical Properties:—Cleavage perfect parallel to 010, therefore across the fibers. Specific gravity 6-488 +003, determined in the pyenometer on ‘6% of mineral (Merwin). Hardness 4°5. Luster adamantine. Plane of the optic axes O. Palache and H. E.. Merwin— Alamosite. 401 parallel to plane of symmetry. Refraction and double refrac- tion high but not determined. Chemical Composition :—A small amount of the mineral was picked out under the microscope as free as possible from adhering quartz and other substances contained in the ore. The absence of cerussite was proved by lack of effervescence in nitric acid. The mineral fuses at 3 to a greenish yellow bead, colorless when cold ; it is easily reduced on charcoal to a lead button and is soluble in nitric acid with strong gelatini- zation. The analysis by H. E. Merwin gave the following result: Per cent Per cent Mol. Ratio ~ for PbSiO; SG) cee eee meen od = 15 "348 21°32 epee rer ee Sy B18 2335) 78°68 Oe at) eS trace aera Sheath FeO . BPN 2h 2 hime 33! "09 Jao peice Residue* from EPbO. 53 pec, agit Inso]. residue, quartz 08 aes Lee 99°94 100°0C * This residue was lost after weighing and was therefore not determined. The molecular ratio of PbO to SiO, is almost exactly 1 : 1, indicating for the mineral the formula PbSiO,. There seems little doubt after considering its characteristics that alamosite should be classified with wollastonite. That it is to be regarded as isomorphous with that mineral is, however, open to question. In favor of this interpretation are (1) sim- ilarity of chemical type and behavior with acids; (2) identity of crystal system and habit; (3) close approximation in the values of the angle 6 and in the lengths of the c-axes; (4) similarity of optical orientation. Opposed to the assumption of isomorphism are (1) difference in lengths of the qa-axes ; (2) difference of cleavage. The case is analogous to the relation of anglesite and anhy- drite where, however, isomorphism is less strongly indicated than in the present pair of minerals. Alamosite is very similar in appearance to barysilite but may be readily distinguished from it by its optical characters. Harvard University, March, 1909. 402. C. Barus—Absence of Polarization in Artificial Fogs. Art. XX XVII.— Absence of Polarization in Artificial Fogs ; by C. Barus. Tue astonishing feature of Tyndall’s experiment, made in the usual way with motes of mastic suspended in water, is the completeness of the polarization of the hght reflected or seat- tered at right angles to the impinging beam. This is particu- larly well shown with the double image prism, in which, for horizontal beams of hight with vertical and horizontal vibration beams and line of sight horizontally at right angles to each other, only one of the beams (that for which vibration is vertical) )is vis- ible in the turbid water. The other is quite extinguished while lying in a vertical plane either above or below the visible beam. In making the same experiment with dense fogs, I was surprised to find an almost entire absence of this discriminating ~ character. Both beains are always in view and about equally intense. These fogs were produced in the fog chamber with phosphorus nuclei and were intensely luminous, with several millions of water particles per cubic centimeter of an average size less than ‘0001. Even for fogs so dense and therefore so fine that the hght penetrates scar ‘cely 30™, both beams were about equally brilliant. On examining the two beams with a Nicol, however, they are found to be almost completely polarized at right angles to each other; whence it follows that the vibration, which is horizontal outside, has been turned about 90 degrees in a horizontal plane after entering. In other words, whereas it vibrates in a horizontal plane normal to the observer on the outside of the fog chamber, it vibrates in a horizontal plane parallel to the observer in the inside of the fog chamber; or, while the plane of the two vibrations is normal to the primary beam on the outside, it is parallel to the two beams on the inside of the fog chamber. The beam with vertical vibrations naturally remains unchanged. Finally, if coronas are produced from a polarized source, they are found to be polarized throughout all their colors and quite extin- guished between cr ossed Nicols. As the motes do not produce coronas and will not subside, it is difficult to specify their size. But the marked occurrence of scattering is sufficient evidence for the absence of regular reflection. “Virtually at least, the particles are very small. With regard to the fogs, however, even in the case of the very finest particles, the light is still regularly reflected and refracted, and not scattered, as in the first instance, to an appreciable Saryon, Lale nee, for a line of vision normal to the primary beam, the direction of vibration may be turned 90 degrees par allel to the plane of the beam and vision, and now v1 ibrates normal to the line of vision, seeing that light is not completely polarized on reflection from a surface of water. Brown University, Providence, R. I. Chemistry and Physics. 403 S ENV Peers Nae GE N-@'E . J. CHEMISTRY AND Puysics. 1. Prussian Blue and Turnbull’s Blue.—Many investigators have studied the well-known blue precipitates produced on the one hand by mixing solutions of ferric salts with solutions of ferrocyanides, and on the other hand by mixing solutions of fer- rous salts with solutions of ferricyanides, but the compositions of the precipitates thus produced under varying conditions have not been perfectly established. MUxivter and Sraniscu have now undertaken an investigation of this subject by the use of what appears to be a more satisfactory method than has been previ- ously employed. Instead of attempting to isolate and analyze the precipitates themselves, they have determined their composi- tions indirectly by mixing known volumes of solutions of known strength, and after analyzing measured volumes of the clear liquids standing above the precipitates, calculating the composi- tion of the latter. All of the substances were determined volu- metrically by means of permanganate solution—the ferrous iron and the ferrocyanide directly, the ferric iron after reduction with zinc, and the ferricyanide after reduction with a ferrous salt in alkaline solution. Several series of experiments with systemati- eally varying proportions of the reagents gave satisfactory and concordant results leading to the following conclusions: The blue precipitates are all ferrocyanides, whether produced from ferro- cyanide or ferricyanide ; the precipitate Fe’, [Fe’(CN),], is pro- duced by mixing solutions of ferric chloride and potassium ferrocyanide in molecular proportions > 4:33; the precipitate KFe’Fe'", [Fe"(CN),], is formed from ferrous ge and potas- sium ferricyanide in molecular proportions > 4:33 the precipi- tate KFe'’[Fe’( CN), + K,Fe*[ Fe"(CN),] is pr oduced from ferric chloride and potassium ferrocyanide in molecular proportions <_ 1:1; the precipitate KFe’’ [Fe’(CN),] is produced from solu- tions of ferrous chloride and potassium ferricyanide in molecular proportions <1:1. It is proposed to study in the fature such proportions as have not been included here, and also to control the results by the determination of potassium.—Jour. prakt. Chem., 1xxix, 81. Hs (Wie 2. The Chemistry of the Radio-active Elements.—The chemi- cal characters of most of the radio-active elements are only imper- fectly known. It has been found that some of them accompany certain well-known elements in precipitations, while others vola- tilize at high temperatures. Whether the volatilized substances are the uncombined elements, their oxides, or other compounds is unknown, while in the case of precipitations the phenomenon of adsorption may play an important part in such exceedingly low concentrations as exist in these cases, so that conclusions in 404 Scientific Intelligence. regard to chemical relations must be drawn with caution. In view of these circumstances, STROMHOLM and SVEDBERG have undertaken a study of the subject by the use of isomorphism. As an example of the behavior of normal elements, the following experiments were made: To equal portions of a warm saturated solution of barium nitrate, equal amounts of dilute solutions of silver, mercuric, lead and bismuth nitrates were added, and after cooling it was found that the erystallized barium nitrate contained neither silver, mercury nor bismuth, but it had taken up much lead in solid solution. From a similar series of experiments with potassium nitrate none of the above mentioned metals showed a solubility in the solid phrase, while in the case of sodium nitrate a considerable amount of silver and a little lead were found in the crystals. The authors applied this method to a solution of Rutherford’s thorium-X, and found that this element is iso- morphous with barium and lead, that it follows barium in its pre- © cipitations, and therefore belongs to the alkali-earth group of metals. Similar experiments with thorium nitrate solutions gave less definite results on account of the numerous radio-active bodies present in such solutions, but it is the purpose of the authors to extend their studies by this method to other series of radio-active elements.—Zeitschr. anorgan. Chem., 1xi, 338. H. L.. W, 3. Lhe Hydrogen Silicides.—LEBEAU, in a preliminary account of his researches on the subject, shows that the hydrogen silicides, produced by the action of hydrochloric acid upon magnesium silicide, are more numerous than heretofore supposed. Besides the two gaseous compounds SiH, and Si,H, already known, it is evident that a liquid silicide exists, and probably also one which is solid at ordinary temperatures. Lebeau condensed a large volume of the silicides by means of liquid air, then by allowing the solid thus produced to attain ordinary temperature a com- paratively small amount of hydrogen silicide, SiH,, free from hydrogen, was given off, while a colorless liquid remained behind. Upon fractionating this hquid there was obtained practically pare Si,H,, which was found to boil at about —7° C. The liquid silicide was obtained only in small quantity and was not satisfac- torily analyzed, but it appears to be silicoethylene, $i,H,. This unsaturated compound is spontaneously inflammable with explo- sive violence when exposed to the air, and it is probably the vapor of this substance which gives spontaneous inflammability to the two gaseous silicides when they are not perfectly pure. The solid substance was observed as a small residue which becomes brown upon exposure to the air and thus yields silicon. — Bulletin, IV, v, 89. H. L. W. 4. Determination of Boron.—Coravux and Boirnav have studied several methods for the determination of this element, including the extraction of boracic acid by means of ether, its volatilization by means of methyl alcohol and its volumetric determination by acidimetry in the presence of glycerine. They find the latter method very satisfactory and particularly well Chemistry and Physics. 405 adapted to the analysis of borotungstates. Precise details of the method of operation are given, together with numerous test- analyses which show remarkably good results.— Bulletin, IV, v, 217. iveelies Wie 5. Canal Rays.—J. Stark and W. SrevsBine continue the studies of J. Stark upon the Doppler effect in these rays, with apparatus affording a large dispersion (a Rowland plane grating with a ruled surface of 816°" and 15,000 lines to the inch). The observations are given in full tables, which give the fall of potential of the dark space and velocity of rays. The fall of potential at the cathode varied from 390 volts to 9600 ; the veloc- ity of the canal rays varied over this range from 1:299°10’ to 1:760°10’. Much space is given to the discussion of the cause of the variation observed in the Doppler effect, especially the maxima and minima. ‘The article closes with a discussion of the observed reflected canal rays, which give a Doppler effect, with a cathode fall of 2500 volts. The reflection of the positive charge of the canal rays amounts to 50 per cent.— Ann. der Physik, No. 5, 1909, pp. 974-998. Jin 6. Zeeman Effect of Mercury Lines.—P. GMELIN has studied this effect with the lines of rare lengths 5790, 5769, 4916, 4358, and shows how the strength of a magnetic field can be measured by a determination of the Zeeman effect. The article closes with the following table : Classen (cathode rays) “= 1-776X10" 1 Bacherer (Becquerel rays) “= 1-730 10" . [e Gmelin (Zeeman effect) == 1-771 X10". p —Ann. der Physik, No. 5, 1909. ue ae 7. Presence of Rays of High Penetrability in the Aimosphere.— The extension of our knowledge of radio-activity has led to much study of the presence of y-rays in the earth and in the earth’s atmosphere. Tu. Wutr describes an improved and _ portable electrometer which is well adapted for the study of radio-activity and he applies it to a study of the y-rays in the atmosphere, finding a winter type without the midday depression which char- acterizes the summer type.— Physik. Zeitschrift, No. 5, March 1, 1909, pp. 152-157. Seats 8. Use of Radiometer for Observing Small Pressures.—J. DEssaRr states that if the residual gas in a radiometer is helium, pulverized carbon cooled by hydrogen is incapable of lowering the pressure so that the vanes will not turn, when the light of the voltaic are is concentrated upon them. On the contrary, when the residual gas is hydrogen the absorption of the gas by the carbon is sufficient to cause all movement to cease. He believes that a radiometer filled with helium will prove a useful apparatus for the study of radio-activity.— Proc. Roy. Soc., London, Series Ie AVOW AXNZIX, 1904 goee: 406 Scientific Intelligence. 9. Wireless Telegraphy and Telephony Popularly Explained ; by Wattrer W. Massie and Cuarves R. UNDERHILL. Pp. 76. New York, 1908 (D. Van Nostrand Co.).—This book is intended. to be a simple, elementary exposition of the inception and devel- opment of wireless telegraphy and telephony. The space devoted to the latter subject is less than four pages. ‘There are a number of simple diagrams and some excellent half-tone plates showing elaborate apparatus. The book closes with a highly speculative “interview” by Nikola Testa, in which a few of the wonders to be wrought within the near future by the application of wireless transmission are briefly outlined. By Bie 10. An Introduction to the Science of Radio-activity ; by Cuartes W. Rarrery. Pp. xii, 208. New York, 1909 (Long- mans, Green & Co.).—The author has “endeavoured to give a concise and popular account of the properties of the radio-active elements and the theoretical conceptions which are introduced by” the study of radio-active phenomena. This work, as its title indicates, does not claim to be more than an introduction to the subject, and no attempt has been made at an exhaustive treat- ment.” ‘The attempt appears to have been distinctly successful, however, and the book is in many respects superior to others of the same class which have previously appeared. The method in which the subject is treated follows very closely along the lines originally laid down in Rutherford’s familiar treatise, and is frequently suggestive of the author’s familiarity with collected works of this sort rather than with the original papers in the literature. A notable and unfortunate exception is to be found in the somewhat detailed discussion of the very questionable results recently obtained by Ramsay in experiments with the radium emanation. Bae II. Gronroagy ann Naturau History: 1. Publications of the U. S. Geological Survey, GEorcE OTIS SmirnH, Director.—Recent publications of the U.S. Geological Survey are noted in the following list (continued from p. 86) : Topocrapuic Atias.—Thirty-seven sheets. Fouios.—No. 160. Accident-Grantsville Folio, Maryland-Penn- sylvania-West Virginia. Description of the Accident and Grantsville Quadrangle ; by G. C. Marrin. Prepared under the supervision of Wuiii1am Buttock CLARK, codperating geologist. Pp. 14, with 8 maps, columnar sections. 3 No. 162. Philadelphia Folio. Norristown, Germantown, Chester and Philadelphia Quadrangles, Pennsylvania-New Jersey—Delaware ; by F. Bascom, W. B. Crank, N. H. Darron, H. B. Ktmuet, R. D. SALISBURY, B. L. Mitter and G. N. Knapp. Pp. 23; 2 topographic maps; 3 colored geologic maps; columnar sections and 21 figures. ge \ A | Geology and Natural History. 407 . 163. Santa Cruz Folio, California. Description of the . >ASanta Cruz Quadrangle; by J. C. Branner, J. F. Newsom and L¥/ Rarpw Arnotp. Pp. 11; columnar sections, 3 maps, II plates. PROFESSIONAL PAPERS. SIN os 58. The Guadalupian Fauna ; UG GrorceE H. Girty. Pp. 651, 31 plates. See p. 413. Sa No. 59. Contributions to the Tertiary Paleontology of the Pacific Coast. JI. The Miocene of Astoria and Coos Bay, Oregon; by Wittiam Hearry Datu. Pp. 278, 33 plates, 14 figures. No. 60. The Interpretation of Topographic Maps ; by Roun D. Satissury and Watitace W. Atwoop. Pp. 84, 170 plates, 34 figures. See p. 265. ’ No. 61. Glaciation of the Uinta and Wasatch Mountains ; by Watiackt W. Atwoop. Pp. 96, 15 plates, 24 figures. See p. 340, No. 63. Economic Geology of the Georgetown Quadrangle (together with the Empire District), Colorado; by Josian E. Srurr and Grorcre H. Garrey; with General Geology by Sypney H. Batt. Pp. 422, Ixxxvii plates, 155 figures. See p. 408. BuLuetins,—No. 353. Geology of the Taylorsville Region, California; by J. 8. Diruer. Pp. 128, 5 plates, 12 figures. See p- 412. / No. 354. The chief Commercial Granites of Massachusetts, : New Hampshire, and Rhode Island; by T. Nerson Daz. Pp. 228, 9 plates, 27 figures. No. 356. Geology of the Great Falls Coal Field, Montana ; by Cassius A. Fisoer. Pp. 85, 12 plates, 2 figures. No. 358. Geology of the Seward Peninsula Tin Deposits, Alaska; by ApoteH Knorr. Pp. 769, 20 plates, 7 figures. No. 359. Magnetite Deposits of the Cornwall Type in Penn- \ sylvania; by Arruur CO. Spencer. Pp. 102, 20 plates, 21 figures. No. 361. Cenozoic Mammal Horizons of Western North America; by Henry Farrrietp Osporn, with Faunal Lists of the Tertiary Mammalia of the West; by Wittram DILLER MarruEw. Pp. 138, 3 plates, 15 figures. No. 363. Comparative Tests of Run-of-Mine and Briquetted Coal on Locomotives, including Torpedo-Boat Tests and some foreign specifications for briquetted fuel; by W. F. M. Goss. Pp. 57, 4 plates, 35 figures. No. 365. The Fractionation of Crude Petroleum by Capillary Diffusion ; by J. Extiorr Gitpin and Marsuatr P. Cram, under supervision of Davin T. Day. Pp. 33, 3 figures. _ No. 366. Tests of Coal and Briguets as Fuel for House- Heating Boilers ; by D. T. Ranpart. Pp. 44, 3 plates, 2 figures. No. 367. The Significence of Drafts in Steam-Boiler Pr actice ; by Water T. Ray and Henry Kreisincer. Pp. 60,26 figures. No. 368. Washing and Coking Tests of Coal at the Fuel- testing Plant, Denver, Colo., July 1, 1907, to June 30, 1908. By A.W. BEtpen, G. RB. Deramarer and J. W. Groves. Eps 23, 2 plates, 3 fioures. 408 Scventific Intelligence. No. 871. Reconnoisance of the Book Cliffs Coal Field between Grand River, Colorado and Sunnyside, Utah; G. B. Ricnarpson. Pp. 54, 10 plates, 1 figure. . No. 372. Bibhography of North American Geology for 1906 and 1907, with Subject Index; by F. B. Wurxs and J. M. Nick LES: pei: No. 376. Peat Deposits of Maine ; by Epson S. Bastin and CuarLes A. Davis. Prepared in codperation with the Maine State Survey Commission. Pp. 127, 3 plates, 20 figures. No. 378. Results of Purchasing Coal under Government Specitications ; by JoHn SHoseR Burrows. With a paper on burning the small sizes of anthracite for heat and power pur- poses ; by Dwieur T. Ranpati. Pp. 44. WaTER Supply Papers.—No. 221. Geology and Water Re- sources of the Great Falls Region, Montana; by Cassrus A. Fisuer. Pp. 89, 7 plates. f No. 225. Ground Waters of the Indio Region, California, with a sketch of the Colorado Desert ; by Watter C. MENDENHALL, Pp. 56, 12 plates, 5 figures. | No. 226. The Pollution of Streams by Sulphite Pulp Waste. A Study of Possible Remedies; by Earte Bernarp PHELps. Pp. 36. Minera Resources of the United States : 1907. In two parts. Part I. Metallic Products. Pp. 7438, 1 plate, 1 figure. Part IL. Nonmetallic Products. Pp. 897, 1 plate, 6 figures. Washington, 1908. The several chapters of this important work have already been issued, in advance, in separate forms. 2. Economic Geology of the Georgetown Quadrangle, Colo- rado; by J. E..Spurr and G. H. Garrey; with General Geology by 8. H. Batu. 4°, pp. 422, 87 pls., 155 figs. ; Prof. Paper 63, U.S. Geol. Survey. Washington, 1908.—While this important work contains an extremely complete study of all the different phases of the geology of the area mentioned in the title, and a very full account of the mineral veins, ores and mines for which the district is noted, and thus presents a great mass of material which it would be impossible to adequately review in a brief notice, probably that feature of the work which is of most importance and general interest concerns the conclusions regard- ing the genesis of the ore bodies to which the authors have been led as the result of their studies. Besides the sedimentary formations in the area which have been metamorphosed into gneisses and schists, the great bulk of the rocks are of igneous origin, intrusive in occurrence and due to successive upthrusts of different magmas mostly in pre-Cam- brian, but some in Tertiary, times. ‘The older these rocks are the more gneissoid is the structure which they exhibit. They vary from granites through monzonites to diorites. They are cut by aplites and pegmatites and by later dikes and masses of porphyry, bostonite, syenite, etc. In general, later than the intrusion of these porphyries, etc., occurred the formation of veins by deposition along fault fissures, which were also later in Geology and Natural History. 409 origin than the porphyries. The mineral veins lie in distinct areas or belts. The greatest contrast in them is offered by those which are chiefly silver-bearing as compared with those which are predominantly gold-bearing. As a result of the investigation of the gold, silver and lead deposits of Colorado two chief natural groups appear, those following injections of a monzonite magma including a large part of the mineral zone with northeast trend across the state, and those which followed isolated local outbursts of magma of an alkalic character. Both periods of ore deposit are of Tertiary age. The ores of the Georgetown district belong in the former northeast belt of which they are a portion. The gold ores are pyritic; the silver ores are galena-blende. Areas covered by the veins coincide with those injected by porphyry dikes and the ore formation is believed to have immediately followed the intrusions. The gold ores depend definitely upon magmas pro- ducing one family of igneous rocks, the silver ores upon a dis- tinctly different magmatic family. Further study of the deposits leads to the belief that the ores have been formed in the case of the pyritiferous gold veins by magmatic waters given off during the pneumatolytic stages of consolidation of certain dikes, due to the intrusion of alkaline magma, while the deposition of the silver-lead ores has followed in a similar way from monzonitic magmas. Since the latter deposits, however, are the older they have suffered much erosion, and in their present status represent the action of a secondary period of concentration and enrichment from descending surface waters. In connection with this the waters of certain hot-springs have been studied and, from their composition and the mineral reac- tions which they produce, it is concluded that they are of mag- matic origin. Many of the minerals which they form are due to reactions with the wall rocks with which they come in contact and thus wall rocks of differing composition have produced dif- ferent sets of minerals. The general conclusion is drawn from the study that the greater portion of the gold, silver and lead ores of Colorado are of magmatic origin and this mode of ore formation, that is their being due to emanations from i igneous magmas, is one of first importance, in comparison with which all other modes of for mation, save in the case of the most common metals, shrinks into insignificance. LV 3. Geology of the Gold Fields of British Guiana; by J. B. HaRRIson. 8°, pp. 320, 33 pls. London, 1908 (Dulau & Co.).— While this volume is ostensibly devoted to a description of the occurrences of gold ores in the colony, it is for the most part made up of areport on the results of reconnaissance work following explorations along several important rivers ; it contains in addi- tion a considerable amount of careful, thorough and excellent petrographical research made upon the rock types collected. Especially to be commended are the very complete and accurate analyses which have been carried out on a considerable number 410 Scientific Intelligence. of rock types. It would be impossible in a brief notice to give any account of the large amount of information contained in this volume, mostly of a detailed local character, but those interested in petrography on the one hand, and those who are concerned with the ecomonic features, such as the gold deposits, on the other, will find init much that is of general importance. 1. v. P. 4. Essai sur la Constitution géologique de la Cuyane hollan- daise (district occidental); par H. Van Cappriir. tude pétro- graphique; par KE. H. M. BEEKMAN. 8°, pp.177 and map. Paris, 1907.—This work contains an account of geological observations made during voyages of exploration along the south bank of the Corantyn (Corentyne) River and along the Nickerie River and one of its branches. ‘The observations are necessarily confined to a narrow strip along the route traversed. Metamorphic rocks consisting of various gueisses, quartzites and schists were observed, frequently cut by igneous masses, granites, diorites and gabbros being most prominent, although other types of rocks also occur. The author discusses the alteration of these rocks and also the character of the soil formed, especially that of laterite. He de- scribes the distribution of gold and its relation to the rock forma- tions. The petrographic study consists of a description of the mineral composition of the large number of rock specimens collected, as seen in thin section under the microscope. | While the work was in the nature of a rapid reconnaissance, it adds considerably to our knowledge of a little known region. Lie Bs 5. The Eruption of Vesuvius in April, 1906; by H. J. Jounston-Lavis, Sci. Trans. Roy. Dublin Soc., Vol IX, Pt. 8, Jan. 1909. 4°, pp. 139-200, pls. 111-xxil1.—The author, who has long been known for his studies of Italian voleanic phenomena and especially of Vesuvius, gives in this paper a general account of this eruption with special details upon certain phases. Outside of these latter, which deal chiefly with a discussion of the petrog- raphy of the products of the eruption and of certain views con- cerning volcanic action which the author has developed as a result of his studies, the memoir furnishes an excellent general description of the eruption and its attendant phenomena; this is made graphically interesting by a series of plates reproducing excellent photographs. In addition two maps add greatly to its value. Lioay aang 6. Zext-Book of Petrology; by F. H. Harcu. 12°; pp. 404; 5th ed., 1909. London (Sonnenschein & Co.).—This ie volume, which contains a short account of the general principles of petro- logy, has been rewritten and given a general redressing by the author. Since such subjects as the rock minerals and their characters under the microscope, the physical characters of rocks, their modes of occurrence and classification, rock textures and a variety of others are dealt with in the first 150 pages, these sub- jects are necessarily handled in a very brief and elementary way. The following 125 pages are devoted to a general description of igneous rocks, these being divided into the plutonic, hypabyssal Geology and Natural History. 411 and volcanic groups, and again subdivided according to the plan whose outline is shown in the succeeding notice. The remainder of the work is composed of a description of the distribution of igneous rocks in the British Isles. While the volume is intended especially for British students, who may desire to attain a knowl- edge of the elements of petrography, there are doubtless many teachers of the subject in this country who will desire to acquaint themselves with the author’s methods and ideas of this subject. Lovee: 7. Classification of the Plutonic Rocks; by F. H. Harca; Science Progress No. 10, 1908, pp. 1-21, reprint.—The writer believes that the physical differences between the abyssal granu- lar rocks and the glassy or porphyritic ones is so great that any scheme of classification which presumes to be of a natural, as opposed to an artificial, character must recognize this. Assum- ing then that the plutonic group is a natural one, he proposes a subdivision of it on chemical grounds, according to the silica con- tent, these groups being again subdivided according to the alkali and cale-alkali contents. In this the “ultra basic” rocks (peri- dotites, etc.), are not included. This gives rise to the following grouping, which sufliciently illustrates the scheme proposed : Alkali Series Monzonite Cale- Series alkali F | Seri a Soda Potash es : Series Series Series Soda- Potash ae Granite| Granite Pen Pe ae SiO. >66¢ SUNS yh eee Famil Famil m se Family| Family a. uae Ne SFT GRANITE FamILy Tes oa Nephelite | Soda- | ae | eee 2.) Syenite Syenite| ye | MonzoNnITE DioRiTE ate Group) ~‘ (Plauenite), E ,| Sub- Sub- FAMILY FAMILY $10,52-66% Famil Famil Sub- oa y| Family Near eet 22 | pore, Sunes FAMILY Basic Nephelite- Essexite Shonkinite Kentallenite) Gaxnsro Group | & eee emo |) oul: Sub- FamLy 810,<522 | Family |Family} Family | Family | whee | ALKALI-GABBRO FAMILY L. Vv. 124. 412 Scientefie Intelligence. 8. Hlements of Optical Mineralogy ; by N. H. and A. N. WINCHELL. 8°, 502 pp., many figs. and col. plates. New York, 1909 (Van Nostrand Co.).—The authors state in the preface that this work had its inception under the impulse of a conviction that English students and independent workers in petrography needed a clear and systematic description of the apparatus used and the methods employed in this science. They feel that the principles, methods and data of optical mineralogy have not yet been pre- sented concisely and clearly in any single publication and it is their aim to supply this deficiency. In accordance with this view the first chapter is devoted to an explanation of the nature of light and such of its phenomena as are of importance in this connection ; the second deals with the elements of crystallography ; the third describes the general phenomena of optical mineralogy and the apparatus used in inves- tigating them from the petrographic standpoint. ‘These three’ chapters contain 100 pages, and of necessity, since they cover so wide a field, the material is greatly condensed. It is illustrated, however, by many figures which serve to explain the text. The remaining portion of the volume is devoted to a descrip- tion of all minerals which are important as rock constituents, or which are sufficiently transparent to have optical properties, especial emphasis in all cases being laid upon the latter in the description. Numerous figures in the text help to convey the optical characters in succinct form. Whether the teacher or student of petrography decides to use this, or one of the several other excellent works we now have, as his main reliance in gaining a mastery of the principles of this subject, he will at all events find this volume a most serviceable handbook of reference with respect to the optical properties of minerals. As such it will prove a great convenience in the library of every working mineralogist and petrographer. | | 1s Vieees 9. Geology of the Taylorsville Region, California; by J.S. DittER. United States Geological Survey. Bulletin 353. Pp. 121, with 5 plates and 12 figures. Washington, 1908.—Little has been published regarding the district in California between Honey Lake and Lassen Peak, a region which has much of geo- logical interest. Dr. Diller’s report shows that the “‘ sedimentary rocks of the Taylorsville region contain a more nearly complete record of the geological history of the Sierra Nevada than has yet been recorded in any portion of the range.” Eighteen sedi- mentary formations are represented: Silurian 1, Devonian 1, Carboniferous 4, Triassic 2, Jurassic 7, Tertiary 1, and Quater- nary 2; the Carboniferous, Jurassic, and Triassic being the rich- est in fossil remains. In place of the single fault bounding the Sierra Nevada farther south, there are in this district at least three more or less parallel fault zones. The easternmost one,— the Honey Lake,—presents an escarpment 2,000 feet high, com- posed of quartz diorite overlain by auriferous gravel and breccia. ; Geology and Natural History. 413 During Cretaceous time, a peneplain was developed by erosion of the Jurassic mountain masses. Hers G. 10. Explorations in Turkestan. Prehistoric Civilizations of Anau. Edited by Rarnart Pumpe ty, Director of the Expe- dition. In two volumes, 494 pages, 97 plates, figures 548. Carnegie Institution, Washington, 1908.—The results of the expedition of 1904 fully justify the expense and the time required for preparation of results; the two volumes, in fact, constitute perhaps the most exhaustive study of deserts, desert. relations, and the influence of arid environments ever published. In addi- tion to the studies of the director of the expedition, contribu- tions from the following authors are included : Hubert Schmidt ; Homer H. Kidder; Ellsworth Huntington; F. A. Gooch; R. Welles Pumpelly ; J. Ulrich Duerst ; G. Sergi; Th. Mollison ; H. C. Schellenberg ; Langdon Warner. The more strictly physio- graphic parts are the following: Ancient Anau and the Oasis- World, pp. 3-80; Physiography of Central Asian Deserts and Oases, pp. 243-337. 11. Glacial Bowlders in the Blaini Formation, India ; by Sir T. H. Hottann. Records of the Geological Survey of india, vol. xxxvil, part i, pp. 129-135. Calcutta, 1908.—The Blaini group of the Punjab, described by Medlicott in 1864, was assumed by Oldham (Records of the Geological Survey of India, vol. xx) to be of glacial origin, although definite proof was not forthcoming. Unmistakable glacial bowlders, recently found in this formation, are described by T. H. Holland. In connection. with the announcement of this discovery, Dr. Holland takes occasion to discuss the age of these beds, which he no longer considers to be Permian, since it is not necessary to correlate them with the deposits of the Talchir (upper Carboniferous) glaciation in. peninsular India. This conclusion clears up many difficulties in Indian stratigraphy and makes it possible to group the unfossiliferous systems of the outer Himalayas, and those of pre-Talchir (pre-upper Paleozoic) and post-Dharwar (post-Huro- nian) age in the peninsula of India. These formations, for which the name Purana has been suggested, are considered wholly or in part pre-Cambrian. H. E. G. 12. The Guadalupian Fauna; by Grorere H. Girry. Prof. Paper 58, U.S. Geol. Surv. 1908 [Feb. 1909], pp. 651, pls. 31.— This extensive and very valuable monograph of the Permian or Guadalupian faunas of southeastern New Mexico and south- -western Texas describes in great detail 326 species, of which about 220 are specifically determined. Nearly all the species are new and the various biota are strikingly different from any other American late Paleozoic formations. In fact the author finds it very difficult to compare the Guadalupian faunas with any other because they maintain a highly individual facies. The only com- parisons that can be made, and these but sparingly, are with the Am. Jour. Sc1.—Fourts Series, Vou. XXVII, No. 161.—May, 1909. 28 414 Scientific Intelligence. Fusulina limestone of Sicily and the Salt Range and Himalaya of India. No comparison at all can be made with those of the Mississippi Valley, for the oldest part of the Guadalupian is younger than any part of the Kansas “ Permian.” ‘‘ Probably the best correlation is that of the Guadalupian on one hand with the Artinsk and Permian on the other” (p. 40). “It would be unwise at present to correlate the Guadalupian series with any definite stage of the Russian section” (p. 41). The Guadalupian faunas consist essentially. of Protozoa (9), Sponges (24), Bryozoa (44), Brachiopoda (128), Pelecypoda (45), and Gasteropoda (42). The more characteristic elements are the large and very abundant Fusulina elongata, of brachiopods Geyerella (1 species), Richthofenia (1), Leptodus or Lyttonia (2), Awlosteges (5), Productus (25), Pugnax (12), Spiriferina (9), Dielasma (5), Dielasmina (2), Notothyris (3) and Heterelasma (2). The Mesozoic bivalve genus Camptonectes seems also to be present. : 2 The new genera are, of sponges Anthracosycon, Virgula, Pseudovirgula, Siromatidium, Guadalupia, Polysiphon, Cysto- thalamia ; a supposed cystid, Coenocystis ; of brachiopods, Heter- elasma ; the pelecypod Protreie; the cephalopod Peritrochia and the trilobite Anisopyge. We have in this book a valuable contribution to Permian faunas, but as the life is that of a distinct province harmonizing best with those of subtropical waters, there is not much guidance to be derived from it in ascertaining the exact time equivalent of the “Permian” of the Mississippi Valley. €.285 13. Cambrian Geology and Paleontology. No. 5.—Cambrian Sections of the Cordilleran Area; by Cuartes D. Watcorr. Smithsonian Miscel. Coll., 53, 1908, pp. 167-230.—Here are described in detail six extensive Cambrian sections ranging in thickness from 5670 to over 13,000 feet. They are located in California, Nevada, Utah, Montana and British Columbia. Throughout the sections the fossils are listed and it is seen that Olenellus has a range of at least 4900 feet. One of the interest- ing facts is the recording in the Pacific province of the genus Holmia, one that is usually regarded as diagnostic of the Atlantic province. Billingsella coloradoensis ranges throughout the Middle Cambrian into the Upper Cambrian. ‘The paper is illustrated by many half-tones of these the finest Cambrian sections. C. 8. 14. Mount Stephen Rocks and Fossils ; by Cuaries D. Watx- corr. Alpine Club of Canada, Calgary, Alberta, Sept. 1908, pp. 232-248, plates 8.—The author describes in this paper the great Cambrian section, Mount Stephen, at Field on the line of the Canadian Pacific railway. Any one collecting the fine Middle Cambrian fossils first noted by Rominger will want this pam- phlet as his guide to the locality and for the determination of his fossils. | C58. Geology and Natural Mistory. 415. 15. Devonian Fishes of Iowa; by Cuartes R. Eastman. Annual Report, Iowa Geological Survey, Vol. XVIII, pp. 29-386, pls. i-xvi and 41 text figures. 1907.—This is a very exhaustive work on the Devonian Fishes, not only of Iowa but also of the North American Devonian, while the fishes of Great Britain and Kurope are of necessity treated for comparison. Chapter I is of an introductory character, in which the author discusses the aim and general outlook of paleontological inquiry, and the relations of paleichthyology to biology. Chapter II is geological and in’ it is considered the stratigraphy of the Devonian fish-bearing beds of Iowa, which form a belt averaging fifty miles in width, stretching along the Cedar river from the Minnesota line to Mus- catine County and thence eastward into Illinois. The Devonian fauna of the state is peculiar in its undiversified character, consisting almost exclusively of Chimzeroids, Arthro- dires and Lung fishes ; there being a notable dearth of Selachians and but one certainly recognized genus of Crossopterygians. The fish-bearing stages are confined to the Middle and Upper Deyonian, their greatest abundance being during the latter period. In his discussion in Chapter III of the evolutionary history of fishes, Dr. Eastman denies the possibility of the derivation of fishes from the Arthropod phylum, but finds no theoretical objection to looking upon some of the worm-like Enteropneusta as the pos- sible ancestors of the vertebrate stem. Documentary evidence of this will probably never be obtained, from the impossibility of the preservation of such soft-bodied creatures in the rocks. for Li light appears to be slightly lower than that for Na light, but otherwise its rate of change 1s approxi- mately the same thr oughout the scale.—A bove 1000° the hght from the furnace itself increases rapidly in intensity, and the light from the sodium or lithium flame becomes rapidly in- sufficient in relative intensity for satisfactory determinations, and intense white light (electric arc) should be employed. In 1890 Mallard and Le Chatelier* measured the birefrin- gence of quartz at different temperatures by means of interfer- ence fringes after the method of Fizeau and Foucault, and observed a sudden decrease in the birefringence at about 570°. For yellow light the following measurements (Table I, column I) are indicated on the curves of fig. 1 of Mallard’s article. Tascie If. I iE Temperature Mallard Wright and Larsen Difference 15: = ‘00917 "00910 "00007 100° = "009045 "00902 "00003 220° = "008865 ‘00882 "00005 535° = °008145 00811 "00004 SiO” = "00804 ‘00797 "00007 590° = "007765 00760 "00016 655° = OOUTT 00762 ‘00015 1060° == “00800 00787 "000138 Table 2. Comparison of the measurements of birefringence of quartz at different temperatures by E. Mallard after the method of interference fringes of Fizeau and Foucault with those of Wright and Larsen using Babinet compensator. In column IJ, the results of the measurements at the same temperatures in sodium light by the writers are included for comparison ; while in column ITI the differences between I and II are given and show the relatively close agreement between the two sets of observations, Mallard’s readings being slightly higher, especially for the S-quartz. In his paper Mallard gives a formula representing the birefringence-temperature curve below 575° and also a second formula representing the curve above 575°. His equations are of the second degree and parabolic in nature, and represent with a fair deor ee Oi * Bull. Soc. Min., xiii, 123-129, 1890. withstanding the relatively large scale. Curve III represents the observed birefringence data of quartz in lithium light ; curve [V, which is not so exact in its definition as II and-III, indicates the change in the angle of rotation of a basal plate of quartz 1™™ thick, with rise in temperature. The measurements of the angles of rotation were less satisfactory owing to thick- ness of some of the plates used and also the difficulty of determining the exact angle of rotation in each case. 430 Wright and Larsen— Quartz as a Geologic Thermometer. TasBLeE III. 17° | 21-71 | 24-71 | 1-71 + 21-71 | B17 | On 71 |) Oa 71 one Reaa 49 21-80 84 21-97 109 22°13 31 | 22-26 46 | 23-10 | 22-00 af | 22°40 76 | 29-10 92°40 84 92-53 210 99-67 29-54 23 22°24 46 22-760 57 22-96 | 99-34 99-97 | 29-88 " 29-54 29°33 84 | 22-50 22:87 312 | 22:80 22-39 | 23°10 a) 22-80 22-90 52 22-86 99-54 60 29:96 | 22:92 93-13 70 22-67 88 | 23°37 409 | 23:07 93:12 | 23:00 | 22:98 23 92-94 29 93-27 . 93°40 49 23-68 | 23:48 23-28 23-20 AY 23°53 23:50 | "3 93-50 | 23°20 91 23-80 502 93°75 93-89 | 23°67 | 23-80 | 93°15 | 23°73 18 93°61 28 23°88 24°10 | 23°38 | 24-08 37 23°80 93-60 | 24:20 50 23-90 51 94°34 60 94:20 | 24-41 24:03 | 24:01 93°76 | 24:45 67 94°59 | 24:20 | 24:11 | 24:20 | 24:17 | 24°55 15 24°31 24-72 | 24:40 | 24:16 94:00 | 24:57 80 95°20 | 24:00 | 25:40 81 24-50 84 DARE 24:22 | 25:10 | 24:60 | 25°40 86 25°41 | 89 25°20 | 97 25°00 | 25:17 | 24°70 | 25°55 607 25-07 | 29 95°17 | 24°73 24-80 29 25°33 39 | 95°12 40 | 25°54 57 | 25°41 | | 67 | 25°47 84. | | 25:20 | | 107 | 25-41 | 94°70 | 25°52 200i | 24:90 | Biel 95°69 | | Fis | 94-80 | 25°50 70 | 24:90 | 99 : 95°54 809 25°95 | 95°24 2) | 24-80 50 | | 24:80 25°84 Wright and Larsen— Quartz asa Geologic Thermometer. 431 accuracy the general course of the curves. Equations of similar nature have also been written down by the writers and the agreement of the calculated values with the observed data is fairly close, but in no case could more than approximate agreement over the entire range of the curve below 575° be obtained. Many equations were solved with a view to adjust- ment throughout the course of the curve, but every formula adopted proved more or less unsatisfactory at certain points along the curve. It can be stated, however. that the decrease in birefringence of quartz from 0 to 575° can be represented approximately by a parabolic curve, while above 575° the birefringence increases gradually and almost as a linear func- tion of the temperature. A more detailed discussion of the different formulas obtained and comparison with Mallard’s formula is interesting but of little direct value in the present instance, and may therefore be omitted. The anole of circular polarization for different temperatures was also measured by the use of the thermal microscope. The results, however, are less concordant owing to the difficulty of determining accurately the exact position of total extinction, and also the difficulty of passing light waves through the plate exactly parallel with the principal axis. Basal plates of quartz of different thickness were cut and polished and the measure- ments carried on in sodium hight. To increase the sensitiveness of the method, the bi-quartz wedge-plate* was used. The results of these measurements are listed in Table II and expressed graphically by curve IV of fig. 1.¢ It will be noted that although the general agreement of single determinations is here less satisfactory than in the data on birefringence, the average value expressed by the curve [V indicates a rise of the angle with increasing tempera- ture up to 575°, where an abrupt increase is observed, while above 575° the increase is shght. The determinations by Joubert and Le Chatelier of the angle of circular polarization in sodium lght for different tem- * This Journal, xxvi, 349, 1908. + The observed values of Table II and fig. 1 have been recalculated for a plate 1™™ thick. The increase in thickness due to expansion at different temperatures has also been taken into account, although this latter factor is of minor influence and practically negligible. Table 5 contains the results of the measurements of the angle of rotation of different basal plates of quartz, calculated to the cniform thickness of 1™™ at different temperatures in sodium light. The noticeable lack of agreement between individual readings on plates at the same temperature is due in part to the difficulty of locating the position of total extinction accurately, and in part to the different size plates used where in large plates it is hardly possibly to preserve uniform temperature throughout the plate in such a small furnace. The difficulty of passing the light through the plate precisely parallel with the principal axis is still a third difficulty which it is not easy to eliminate under the conditions prescribed. 432 Wright and Larsen— Quartz as a Geologic Thermometer. peratures are of interest for the sake of comparison and are included under column [ of Table 4. In the second colamn the average result of the measurements of the present writers. for the different temperatures is given, and a comparison of the two columns shows agreement as close as could be expected and well within the limits of error. The measurement of the angle of rotation of quartz is less accurate at all temperatures than that of the birefringence, and such close agreement between individual readings cannot be expected, especially if plates of different thickness are used, as in the present series of determinations. Tape IV. Angle of rotation Angle of rotation Temperature (Joubert and LeChatelier) (Wright and Larsen) Difference ik ne 20° Qe yey Daleiyalhs 0°01° 100 J* 21°98 21°96 0°02 280 22°68 22°58 0°10 360 J 23°04 22°90 0-14 415 23°40 23°15 0°25 448 J 23°46 23°30 OnGiees 560 24°30 24°10 0°20 600 25°26 LOPLY) 0°06 840 J 25°26 Bese) wae 900 25°32 ee ge 1500 J 25°42 the angle of rotation of basal plates of quartz 1™™ thick at different temperatures in sodium light are compared with those of Wright and Larsen for the same temperatures. The actual poimt of change is still] further emphasized by the behavior of the basal crystal plates themselves at the inversion temperature. In passing through 575° the optic phenomena become temporarily disturbed and there is no position of total extinction. As soon as this temperature is passed, however, the abnormal behavior subsides and accurate measurements can again be made. This effect, which is most pronounced on thick plates, may be due in part at least to unequal distriou- tion of the heat and consequent lag in inversion of one part of the plate after another, while the optical effect observed is that from the whole plate.—To test this behavior still further, a plate parallel to the principal axis was taken and observed in parallel position between crossed nicols. In this imstance, however, no hghting up of the field was observed at the inver- sion temperature, thus indicating that the change which takes place does not affect the vertical c-axis appreciably, it remain- ing strictly parallel throughout the inversion. * Measurement by Joubert, Comptes Rendus, lxxxvii, 497-499, 1878. Wright and Larsen— Quartz asa Geologie Thermometer. 433 The abrupt change in expansion-coeflicient observed by Le Chatelier at the inversion temperature causes thick plates of quartz to shatter more or less completely, the planes of fracture running parallel with the unit rhombohedral faces ordinarily. This shattering is so characteristic that it is pre actically impossible to bring a thick quartz plate through the inversion temperature, either up or down, without some cracking, usually sufficient to spoil the plate for further use. Thin plates, on the other hand, bend noticeably. Miigge* observed the tem- porary warping of a thin plate of quar cal Sey thick) through an angle of 3° at the inversion temperatu Above and below the inversion temperature, however, e te: appeared per- fectly plane, thus indicating practical identity of the axial ratios of the a and 8 torms. The above determinations of the inversion temperature were made with a direct reading Siemens and Halske millivoltmeter, the scale divisions of which registered temperature intervals of 10°, 0-1 division being equivalent to 1° and the absolute accuracy perhaps + 5°. "To standardize these readings and at the same time to test the sensitiveness of this inversion in quartz (which is exceedingly inert in its change to tridymite and also to the viscous amorphous state), a quartz plate about -28"" in thickness and parallel with the principal axis was selected and its birefringence bands in the Babinet compensator observed, while the readings of the thermoelement on which the plate rested were recorded ona potentiometer.+ This system was sensitive to temperature differences of perhaps ‘02° and its absolute accuracy was well within + 0°5°. The point of change was indicated in the microscope by a sharp movement of the dark interference band of the Babinet compensator, and at this instant the reading on the potentiometer was recorded. The inversion, both on heating and on cooling, was observed a number of times and the temperature of inversion found to be remarkably constant and sharply marked. The readings are included in Table V, columns I-IV. The greatest difference in the observed temperatures of the inversion during heating is 2 microvolts, or about 0-2°, while that for cooling is some- what greater. Although the thermoelement readings were expressed in microvolts, the equivalent temperatures in degrees are listed in Table V. It was found that notwithstanding differences in rate of heating, the inversion point on heating was practically constant, whereas the reversion point on cooling * Loe. cit. + The methods here adopied for the testing and standardizing of the ther- moelements used are due to Dr. A. L. Day, and to him the writers are fur- ther indebted for all thermoelectric measurements recorded in the following paragraphs. 434. Wright and Larsen—Quartz as a Geologic Thermometer. TABLE V. Thermoelement of Microscope. Temperature of change. Freshly drawn thermoelement from standard - thermoelement wire. Bea Plate I. Temperature of change. Temperature Cade ests cei h Quartz- Plate II. of mae. Swaine Creer 3 in furnace change. ae reversed. Quartz- Plate wee Rate of heating Rate of Seeitne | 5 vee 2 2 | 2 2 2 Fast Slow | Fast Slow |Rising & Falling ¢ Rising Falling ¢ Rising & eee 5768 | 576-7 | 5749 | 575-2 578-7 feo sl578-4 fib724 Ff lb764 Flavowess 576°8 | 576-7 | 575-0 | 575-3 1573-4 s |b72°7 s/573°6 fF 15728 slb763 flo. s 576°7 | 576-8 | 5748 | 575-3 '578-4. s (572°6 8573-5 Ff /572°8 5 5761 ws 0707 s 576°5 | 576°7 | 574-6 | 575-2 1578-4 ff (57276 s5734 f 5726 f 576-1 vs 9706 s B760 7) | 516°6.510:04l ona 2) Ono 4 sjamole 2 a | S762 s 0704 s 576°7 rae | O729 ff, | O10 576-7 5749 | SY 6a | OMCs fs 576°8 | 574:9 | | 576°7 | 574-6 | | | 574-5 | | 576°7 | 576-7 | 574-8 | 575-2 5738-5 «(572-6 «= s7B-5~—s*72°6 «Ss 6S lowes | | | | ye USO Sy Sion Table 5. In this table the results of the determination of the temper- ature of inversion of quartz by means of the abrupt change in its birefring- ence at this temperature are recorded. In the first four columns the read- ings of the ordinary thermal microscope thermal element are given, while in the remaining six the readings on a standard thermoelement of specially thin wire are presented. The point of inversion was recorded both for rising and falling temperatures and different rates of heating and cooling the quartz plates. varied slightly with the rate of loss of heat. To insure still further the accuracy of the determination of the temperature of inversion, a new and carefully calibrated thermoelement of fine wire drawn down from one of the laboratory standard thermoelements * was taken and the observations in the ther- mal microscope repeated, the readings beimg taken as before on the potentiometer. The results show again the extreme sensitiveness of quartz to minute temperatnre differences at the inversion point, and establish the temperature of inversion at 575°8°+1-0° for the first specimen (Quartz plate 1), 573°0° + ()°5° for the second (Quartz plate 2), and 5753 2-04 aor the third (Quartz plate 3), or in general for this constant, 575°. +2°. The results of these observations are recorded in able 5 above. Plate 2 was -232"™ thick and covered an area of * It was found necessary to take this precaution and to use wire *2™™ in dia- meter, in place of the standard theromoelement wire 0°6™™ in diameter, since the latter conducts away more heat in unit time than a smull furnace can supply, and as a result the readings with it are uncertain and too low. Wright and Larsen— Quartz as a Geologic Thermometer. 485 20°4 sq. mm.; plate 3 was -224"™ thick and covered an area of 6-8 sq. mm., or one-third that of plate 1. This difference in size of the two plates might account, in part at least, for the differences in inversion temperature recorded. The temperature determinations in the thermal microscope were furthermore checked by means of heating and cooling eurves after the method of Frankenheim,* on a large mass of pulverized pure quartz. Although the most sensitive experi- mental conditions (temperature change of -01° visible) were adopted, the thermal effect of the inversion was exceedingly slight and was furthermore distributed over a temperature interval of 20° or more. Nevertheless, on both the heating and cooling curves a slight absorption and corresponding release of heat could be observed in the inversion temperature region. To designate any particular portion of these temper- ature intervals for especial interpretation is little more than arbitrary where the total energy involved is so small, but the temperatures at which the rate of absorption (or release) was ereatest are epprosinatcly as follows: On heating, 560°, 559°, 569°, 564°, average 563°; on cooling, 560°, 562°, average 561°. It is not even safe to say that these numbers represent the average inversion temperature for a great number of quartz fragments, for finely pulverized quartz is such a poor con- duetor for heat that the temperature of the charge cannot be assumed to be uniform from surface to center during such a measurement. The thermoelectric record accordingly lags and the temperatures given are necessarily low. The deter- mination by this means is therefore only approximate and the method merely confirms in a general way an absorption and release of a small quantity of energy in this region, but is not competent to locate so small a quantity accurately. Very recent and still incomplete measurements by Dr. W. P. White, of the Geophysical Laboratory, on the specific and latent heats of quartz indicate an abrupt change i in the thermal capacity of quartz in the region of the inversion temperature. At about 575° the specific heat measures -282-++--017, where the (large) probable error (+017) includes the energy change in passing the inversion point. The latent heat at 575° is 4:3 +1 calories. There are some uncertainties in both the latent and specific heat values due to the fact that a sufficient number ot observations has not yet been taken to determine, with sufficient accuracy, the character of the function near the dis- continuity. The above measurements and data prove definitely that quartz undergoes a small energy change at about 575° and that the change is reversible or enantiotropic. The amount of * Measurements by Dr. A. L. Day. 436 Wright and Larsen— Quartz as a Geologic Thermometer. energy involved is, however, so small that thermal methods of stndy are relatively unproductive compared with optical methods. | . It is of interest to note that in a substance like quartz, which in some respects is exceedingly inert and sluggish, certain changes of equilibrinm are extremely sensitive to “temperature differences, a difference of one tenth of one degree being sutticient to cause the shift from the one form to the other. It is indeed difficult to form an adequate and satisfactory picture of a mechanical system which shall satisfy the conditions of such nice equilibrium and adjustment. In the case of quartz, however, it is fortunate for the observer that certai physical properties which can be determined with great accuracy at different temperatures are extremely sensitive to the i inversion, since the actnal change in energy content, or amount of heat involved in the transformation, is extremely slight, and too small, in fact, to be detected by ordinary methods for meas- uring temperatures, Notwithstanding the comparatively i insig- nificant amount of energy required in the transformation, it is still sufficient to cause a readjustment of the crystallographic forces, such that the low temperature a-quartz and the high temper ature 6-quartz crystallize in all probability in different subdivisions of the hexagonai system, and at the same time, inineate twinning phenomena may be set up, the effects of which are in general sufficient to enable the observer to distin- euish a- quartz from $-quartz. The criteria which have been developed for pesontpfelnities this distinction will now be con- sidered briefly and these in turn applied to different quartzes as they occur in nature. In arecent paper, Miigge* has proved that 8-quartz crystallizes in all probability in the trapezohedral-hemihedral division of the hexagonal system, and that its axial ratios are practically identical with those of a- quartz.—The chief crystallographic change which takes place at the inversion point is a molecular rearrangement such that the common divalent axes of the high temperature ®-form become polar in the a-form stable at low temperature, and a tendency to restore erystallographie equi- librium in the a-form by twinning after the prism is therefore active on the inversion from the high B-form. This twinning phenomenon is best studied by means of etch figures (obtained by immersing for 14 hours plates of quartz in cold commercial hydrofluoric acid) on the basal pinacoid. Miugge found that if a plate of untwinned quartz after (0001) be heated above the inversion point and, after cooling, etched, it is no longer a simple crystal, but an intricate complex of twins after (1010), the twinning lines being asa rule irregular and without definite * Neues Jahrb. Festband, 181-196, 1907. Wright and Larsen— Quartz as a Geologic Thermometer. 437 arrangement. If, furthermore, a regularly twinned crystal of quar iz be heated above 575° and then etched on the basal pina- coid, the twinning lines are as a rule no longer straight and reg- ular, but the field: appears divided by small patches of irregularly twinned material. In passing from the tetartohedral a-form to the hemihedral 6-form, the bivalent common axes lose their polarity and the tendency in the latter form to form twins, therefore, is much less strong than in the a-form. On revert. ing later to the a-form, the common axes of the 8 form become again polar and the tendency during the molecular rearrange- ment is again to form twins, and, in this instance, twins with irregular boundary lines, since the change takes place rapidly and in the solid state.—The form and character of twinning on basal sections of quartz can therefore be used as one of the eriteria in determining whether or not quartz has been formed above or below 575° C. Still a second fact of observation can be used to advantage in ascertaining the original temperature of formation of quartz.* Quartz is circularly polarizing and may rotate the incident plane polarized light waves either to the right or to the left. Experiments on the erystallization of circularly polarizing bodies have indicated that a slight change in the mother solution is often sufficient to change the character of the rotation of the crystal being precipitated. In quartzes formed at low temperatures, vein “quartzes and the lke, one might expect intergrowths of right- and left-handed crystals more frequently than in magma quartzes where rapid changes in the composition of the solutions are less likely to oceur.—In the low temperature quartzes crystallizing out of quietly circulating solutions, moreover, the conditions are less violent than in a magma above 515° and the processes of precipitation might well be considered to proceed with more regularity and uniform- ity at the lower temperatures than above ‘the inversion point. The tendency of intergrowths of right- and left-handed crystals of the low temperature phase should accordingly be toward regularity of outline of the intergrowths and toward hexagonal symmetry.—The fact of intergrowths of left- and right-handed quartz and the character of such intergrowths is a second factor to be considered in the investigation of any particular quartz. A third feature which is of service in this connection is the shattering and cracking of quartz crystals on passing the inver- sion temperature as a result of the abr upt change in the coefii- cient of expansion. This occurs both on heating and on cooling. It is safe to assume, therefore, that large clear quartz plates ‘free from fractures have in all probability never reached the inversion temperature. The fracture cracks in many small * Miigge, O., loc. cit. Am. Jour. Sci1.—FourtH Series, Vou. XXVII, No. 162.—June, 1909. 30 438 Wright and Larsen— Quartz as a Geologic Thermometer. grains are present only potentially, and appear so distinctly on etching that an apparently clear plate of quartz which has been heated above 575° may ernmble down in the etching acid and break up into a number of small grains, while the purely a-quartz remains intact and is etched with much greater uniformity.—The fact that thin plates of quartz may warp and bend temporarily at the inversion temperature, thus find- ing relief from the strains set up on the change, while thicker — plates bend less easily and tend to fracture more readily, is a factor which should be considered in any particular case. Small grains, being thus less liable to- fracture, may not show the phenomena of shattering as clearly as might be expected. Crystallographically, the difference in crystal class between the a-and #-forms finds expression in the crystal habit. In the 8-form, the pyramid faces are equally developed; trigonal trapezohedrons are absent, the habit of the crystals being usually that of.the simple dihexahedrons observed in quartz porphyries and allied rocks. Crystals of the low temperature a-form, on the other hand, are usually prismatic in habit and often show marked differences in the size and character of the rhombohedral faces. ‘Trigonal trapezohedrons may occur and stamp the crystal on which they do appear at once as a low temperature form. Briefly stated, the four criteria which can be used to distin- guish, at ordinary temperatures, quartz which was formed above 575° from quartz which has never been heated to that temperature, are: (1) Crystal form, if crystals be available, the presence of trigonal trapezohedrons and other evidence of tetartohedrism, irregular development of the rhombs and the like, being indicative of the a-form. (2) Character of twinning, as shown by etch figures on the basal pmacoid. In the a-form, which erystallized from solutions at comparatively low tempera- tures, the twinning is usually regular and sharply marked, while in quartz plates originally of the 6-form and now a by virtue of inversion in the solid state, the lines are usually irregular, and the twinning patches are small and bear no relation to the outer form of the crystal. (3) Intergrowths of right- and left-handed quartzes are more frequent and more Tabie 6. In this table are assembled the results of the examination of 44 different quartzes occurring in nature. A number of basal plates of each of these quartzes were cut and polished and etched for 75 minutes in cold commercial hydrofluoric acid. The quartzes were examined particularly with respect to: (1) the occurrence and character of intergrowths of right- and left-handed individuals of quartz; (2) the frequency and character of the twinning of the quartz plates as brought to light by means of the etch figures obtained by immersion of the plates in hydrofluoric acid ; (8) the character of the plates themselves, whether clear and comparatively free from cracks or much shattered and often crumbling after immersion in hydrofluoric acid. Wherever crystals were used these were examined still further for evidences of tetartohedrism. Wright and Larsen— Quartz as a Geologic Thermometer. 439 TABLE= Vi: pus | Intergrowths | Twinning i) a ——s =| 2 z | oi | 2 is a | Degree eres Ss | 3 aps & 52.85 of heen ete 2 Character S| Blos A |S | W's Shattering. he 08 oS : of 2 B| 9 6S Bea (pee a H intergrowth (4/4 Sie & aad Puech a sees ee se 2 68 7, |< | Be ae = | Soe RN | | | pages Saeed 1] 6 5 jWewccracks, clear) 6 | __ | -- pst eae ber Gulee™ 221). 2 Ss ee Ge eS, 3 |Straight & regular 2 | 14 | ¢ all; 8 2 2 Z 8 Regular Doe eee 410 7 10 ee CERN x oligo pl Onc as ivteey 524 3 se 2 NSE IC See 14 | 10)\a 6112; 3 of 8 Set 4 |Straight & regular} 11 | 1/| a waa 6 zh ae 11 ae nee Steller 8} 8} 95 = 5 2 1 Regular Qrcle bea eed 9116) 6G = 8 2, wee Benge 4;12}a 10/6} *.. 8 2 i cg eae iene Se eee area ee eee #tpeal. 10 a 5 ne ae bad aie ep embed 12)11, 12 Te 1S erie OD rae pee Bee 2\. 9)a 13} 8 8 cs 4 1 OS aha Ma Fs Sag A Asal 14.8 10 ee a 8 Seat TT A Finch” ry 2 es 6 61a 1515 = =6 . is fees tedet Regular DA StOo a 1614 35 my 8 3 if oe 4} 9]a 1710; 3 . ar Bape elie at cok oe Dee Qetre 1815 5 | Some cracks 9 4 1 Regular oi) Maes ee) at 19| 7 7 ‘Fewcracks, clear] __ ce 7 il Selene A: 7 | | es 9 Pale e i Lae oe ee o| 4]/a rl 8 Many cracks 1 11 Eps MO oa S21 Salsa ina 22112; 2 x 9 yond ae eee Be Late y 2313) 19) es 2 eee ete ores Scene Ole SON lacs 2411; 1 | Much fractured 3 8 hai ci eg a Ope por let 25/21; 2 ons 21 Scent RA ae Wes WEN a eC OL yh 26| 6| 2 a Ee Go ery ete ® oes Es ee 2711, 3 Some cracks 3 i) Sy epeee ney ee ae eae Aaa 2811; 2 : 4 4 3 Irregular Or line daltee 2913) 3 S 4 oe Ren Nhe Sa se Eh aon laa & ao} 4¢ 2 | i 4 aa EME We aa tenets 2 Te ees a 3114 2 i U Sia@ ete eee ead SE ON A a2, 4, 1 | Much fractured 2 2 EE | Moa ee EL oe a al ae <7 (85) ees 1 eee he stamie Sones Se mlgies hepa 34,4 2 re Bot 2 VSO CN Macatee eee 7 ae ao] 7} 2 . 2 TSR" | ia ey dS ie Se Ieee ye 36,10, 2 | os 4 Dee es wh, ae ae. OW hepa S7| 3) 2 as 2 eS 2 Fairly regular mee see ef asi10 2 < 5 4 ile ee he eee ea ao) 2: 2 x, i ese Bae ie be 3 40} 6 3 i f Realty ese Set ee Aone Atl 3 | “ay dy Bihar Seka k Sor Sh Py Reet Bb hes 42/16 2 | a if Sper ees Py es@ ae Aa eee ee 43/16 1 | 5 5 Cae ete See Bt Os kok 4445 1 ef 5 sei 2 US le) 3 ee ==" De lor *In this column the letter @ signifies regular: 6, usually regular; c, often irregular, tendency toward regularity ; d, rather irregular; e, small, rather irreg- ular ; f, irregular and small. 440 Wright and Larsen— Quartz as a Geologic Thermometer. bo 3. 10. tial: 12. 13. 14. Specimens used in Table VI. White vein quartz. Auburn, Maine (U.S. Nat. Mus. Spee. No. 75,530). Specimen of glassy quartz, transparent in spots and comparatively free from fine cracks. Fracturing after (1011) noticeable. White milky vein quartz in limestone, associated with galena and sphalerite. North Arm, Moira Sound, Prince of Wales Island, Alaska. (Charles W. Wright, collector.) Quartz crystals. Forms: (1010), (1011), (O111), (2120) U.S. Nat. Mus. No. 45,205). Crystal Mt., near Hot Springs, Arkansas. Clear, transparent crystal groups. Large quartz crystal traversed by shearing planes almost at right angles with principal axis. Parts of crystal clear and transparent. Locality unknown. White vein quartz near Canaan, Conn. Vein occurs in metamorphosed Cambrian limestone directly overlying Ver- mont quartzite. Quartz is associated with tremolite. (A.C. Spencer, collector.) Quartz vein in Cheshire quartzite, Ashley Falls, Mass. White, transparent in spots. Occasional flakes of muscovite occur in this quartz. (A. C. Spencer, collector.) Quartz associated with magnetite and garnet. Lover’s Hole, Barton Hill, N. Y. Quartz is fairly massive and clear in spots. (A. C. Spencer, collector.) Vein quartz. Group of crystals (1011), (O1i1), (1010. Glacier Basin near Wrangell, Alaska. Zonal structure well developed. Crystals massive. (Fred E. Wright, collector.) Vein guartz in Precambrian schists. Sugar Loaf, Md. Crystals bounded by (1010), (1011), (0111). Rhombohedral development prominent. In general quartz is milky in color. Small crystals are transparent. This group contains speci- mens from three different veins a mile or more apart in the schists. (EH. S. Larsen, collector.) Quartz crystal. Herkimer County, N.Y. Doubly terminated crystal (1010), (1011), (0111), occurring in metamorphosed limestone. Rose quartz. New Milford, Conn. (U. 8S. Nat. Mus.) Massive and comparatively clear quartz. Rose quartz from quarry P. H. Kinkle’s Sons, Bedford, N. Y. Occurs in large pure masses in coarse pegmatite, associated with large masses of pure feldspar, both minerals grading into graphic intergrowths of feldspar and quartz. Spec. 753. (E. 8S. Bastin, collector.) Rose quartz. Paris, Maine. (U.S. Nat. Museum.) Massive and clear rose-colored quartz. Rose quartz. Maine. (U.S. Nat. Museum.) Massive and pale rose-colored quartz. Smoky quartz. Berry feldspar quarry, Poland, Maine. Crystals project inward from walls of gem-bearing pockets Wright and Larsen— Quartz as a Geologic Thermometer. 441 16. iy 18. 19. 21. 22. 23. 24. of large pegmatite dike. Massive and clear material. Spec. 539. (EH. 8. Bastin, collector.) . White quartz. J. A. Fisher feldspar quarry, Topsham, Maine. Large mass of pure quartz several feet across in pegmatite dike. The masses of pure quartz and feldspar at this quarry grade irregularly and without break into coarse to fine graphic intergrowths of these two minerals. Spec. 699. (KE. S. Bastin, collector.) White quartz from pegmatite dike one mile northwest of Cumberland Mills, near Portland, Maine. Dike cuts mica schist and granodiorite. Large quartz masses grade into coarse granite pegmatite, either gradually or abruptly.. Large quartz masses appear to form end product of the pegmatite crystallization. Spec.717. (EK. S. Bastin, collector.) Quartz associated with rounded lepidolite and bladed albite. Berry feldspar quarry, Poland, Maine. This specimen was taken from the gem-bearing portion of the pegmatite dike from which the Spec. No. 15 of smoky quartz was derived. — The portion of the dike bearing lepidolite and albite is marked by pockets containing crystal quartz and occasional gem tourmaline, and appears to have been without doubt the last to crystallize out. Spec. 402. (EK. 8S. Bastin, collector.) Quartz from pocket in very coarse-grained pegmatite. Major Willis feldspar quarry, Topsham, Maine. Spec. 371. (E. S. Bastin, collector. ) Quartz from coarse-grained pegmatite. Old feldspar quarry, Northwest side of Mt. Ararat, Topsham, Maine. Quartz crystal with faces projecting into feldspar. Spec.361. (E.S. Bastin, collector.) Quartz from pegmatite in granodiorite two miles east of Dress Pt., Hassler Island, Behm Canal, Alaska. Aplitic pegmatite, coarse-grained and consisting essentially of quartz and oligoclase with some muscovite and biotite. Spec. 5 F.W. 50. (Fred. E. Wright, collector.) Quartz from small granite pegmatite dike. Railway cut opposite Rumford Falls near Rumford Falls, Maine. Typical pegmatite from southern part of Maine. Spec. 440. (E.S. Bastin, collector.) Quartz from graphic pegmatite. Andrews feldspar quarry, Portland, Conn. Specimen fairly coarse-grained and consist- ing essentially of quartz and feldspar. (E.S. Bastin, collec- tor.) Quartz from granodiorite pegmatite, West Entrance Point, Bailey Bay, Behm Canal, Alaska. Aplitic pegmatite, coarse grained and similar in composition to No. 19. Spec. 5 F.W. 40. (Fred. E. Wright, collector.) Quartz from graphic pegmatite. J. A. Fisher feldspar quarry, Topsham, Maine. This specimen was taken from the same quarry as No. 16 and is interesting because it appears to have been formed above 575°, while the large masses of 442 Wright and Larsen— Quartz as a Geologic Thermometer. 26. | WO) 29. 30. 3]. oA, 30. 36. ~t No. 16 appear to have formed below that temperature, thus indicating a temperature of formation of the large part of the pegmatite at about 550°-600°. Spec. 701. (KE. 5. Bastin, collector.) | Quartz from graphic pegmatite. Ilmen Mts., Miask District, Urals, Russia. Coarse pegmatite consisting essentially of microcline and quartz in characteristic graphic intergrowth. (U. 8. Nat. Museum.) Quartz from ore-bearing pegmatite vein in sodalite-syenite. Bancroft, Ontario, Canada. Quartz is associated with siderite, arsenopyrite and various sulphides. (A. C. Spencer, collector.) Quartz from irregular pegmatitic mass adjacent to magnetite ore, in Precambrian gneiss. O’Neil Mine, Monroe County, N. Y. Dark colored rock, coarse-grained and consisting essen- tially of abundant hornblende, microperthite and quartz with some biotite and secondary chlorite. (A. C. Spencer, col- lector.) Quartz from coarse pegmatite mass near magnetite ore body. Stirling Mine, Lakeville, N. Y. Specimen consists of magne- tite, hornblende (uralite?), biotite, quartz feldspar and some secondary chlorite. Quartz occurs in small patches and granules, scattered throughout specimen. (A. C@. Spencer, collector. ) White quartz from pegmatite in gneiss. Great Barrington, Mass. Specimen consists chiefly of quartz with occasional prisms of brown transparent tourmaline. (A. C. Spencer, collector.) | Quartz from pegmatitic mass in gneiss on John Keleyl’s - farm, northwest end of Mt. Eve, Orange County, N. Y. Specimen consists chiefly of magnetite, quartz and some feldspar. (A. C. Spencer, collector.) 7 Quartz from granite. Near Lake Bennett, B. C., Canada. Medium-grained, pink biotite granite. Spec. 314. (KF. E. Wright, collector.) Quartz from granite gneiss one-half mile north of Carpenter Knob, Cleveland County, N. C. Gneiss consisting of feld- spar, quartz, biotite and muscovite. (Arthur Keith, collector.) Quartz from altered granite, near Cambourne, Cornwall, England. Specimen taken near tin ore deposits and. consist- ing essentially of pink feldspar quartz and black tourmaline. (F. E. Wright, collector.) Quartz from altered granite near Cambourne, Cornwall, England. Specimen from near tin ore deposits and intensely altered. Much quartz and gray green altered feldspar, muscovite and tourmaline. (F. E. Wright, collector.) Quartz from granodiorite. Near Log Cabin, White Pass, B. C., Canada. Essential components of specimen are quartz, oligoclase, orthoclase, and biotite. Gray medium-grained intrusive. Spec. 303. (EF. E. Wright, collector.) Wright and Larsen— Quartz as a Geologic Thermometer. 448 , 37. Quartz from granite. East slope of El Sobranti, near Corona, California. Gray medium-grained granite consisting essen- tially of quartz, alkali and soda, calcic feldspars and biotite. Spec. 10. (E. 8S. Larsen, collector.) 38. Quartz from granite. Near Pevey, Lake Bennett, B. C., Canada. Pale “pink medium-grained granite consisting essen- tially ef quartz, orthoclase, oligoclase and biotite, and some visible magnetite. Spec. 312, a EK. Wright, collector.) 39. Quartz from granite near Meissen, Saxony, ‘Germany. Pink, fresh, medium- -grained granite consisting essentially of quartz and feldspar with some biotite. (Charles W. Wright, collector.) 40. Quartz from granite. Marble Falls, Burnett County, Texas. Medium to coarse-grained pink granite, consisting essentially of quartz, feldspar and biotite. Spec. 38,824, U. 8S. Nat. Museum. 41. Quartz from miarolititic pegmatitic cavity in granite. Railway cut near Glacier, Skagway, Alaska. Granite is exceedingly variable in eranularity and consists essentially of quartz and feldspar with some biotite. Spec. 282. (F. H. Wright, collector.) 492. Quartz fant granite porphyry, Bassett Mine, Cambourne, Cornwall, England. Granite porphyry with phenocrysts of , dibexahedral quartz, orthoclase and tourmaline. (F. E. Wright, collector.) 43. Quartz Soar granite porphyry. Yankee Creek, Brooks, Mt. Seward Peninsula, Alaska. Gray granite porphyry with phenocrysts of quartz and orthoclase. (Adolf Knopf, col- | lector.) 44. Quartz from quartz porphyry. Verdugo Protero, ten miles south of Corona, California. Phenocrysts, quartz and feld- spar. Fresh, gray dike rock in andesite. Spec. 190. (EH.S. Larsen, collector. ) ® regular in boundary lines in the a- than in the @-form. (4) Plates of originally S-quartz but now a-quartz by inversion show the effect of the inversion by the shattering which should be most evident on large plates.—Into all these criteria an element of probability enters, and in testing quartz plates, with this end in view, a number of plates should be examined to strengthen the validity of the inferences drawn. It was of interest to apply these criteria to actual occurrences of quartz in nature, and for this purpose 44 specimens of quartz and quartz-bear ing rocks from different localities were chosen, 10 specimens of quartz from veins and geodes, 21 from peg- matites of different types and 13 of granites and granite por- phyries. From each specimen from 3 to 25 plates after the basal pinacoid were cut and polished on both sides.—Each plate was then examined with reference to its circular poelariza- tion and the character of its twinning. All plates were etched 444 Wright and Larsen— Quartz as a Geologic Thermometer. uniformly in cold commercial hydrofluoric acid, the time of exposure in every instance being 75 minutes. The etched plates were examined at first both in reflected and transmitted light, but experience soon indicated that the best results were obtained by observing the etched surfaces and figures in transmitted light, the rays being obliquely incident at such an angle as to cast proper lights and shadows across the small etch pits and hills. Even in the process of etching the difference between the high and low forms was often evident. The crystal plates of the a-form were as a rule clear and without fractures, and although on etching all such cracks were promptly discovered and emphasized by the acid, the general appearance of the plates after etching was nevertheless uniform and con- tinuous. Plates of original 8-form, on the other hand, even though clear, before etching, developed after short exposure in the acid numerous cracks, potentially present before, which frequently caused the plate to crumble and break up into smaller grains. As a rule etch figures on such plates were also the least satisfactory. The character of the circular polarization of the different plates was ascertained in sodium light, the lenses of the con- : densor system of the microscope having been removed and the plates observed with a low-power objective. After etching the plates were re-examined, the disturbing influence of reflec- tions on the etched surfaces being eliminated temporarily by immersing the plates in a liquid of refractive index 1°554, equal to » of quartz. A detailed discussion of the results assembled in Table 6 substantiates in a general way the theoretical inferences. Of vein quartzes, 10 specimens were used, 125 basal plates cut and polished and etched; of these 49 showed right-handed circular polarization, 50 left-handed,.16 left- and right-handed intergrowth of fairly regular outlines; 50 plates were not twinned, while 63 were twinned, the outlines of the twinned areas being in general regular and indicative of hexagonal symmetry. Practically all of these plates were free from frac- ture cracks of any importance. Twenty-one specimens of peg- matite were examined and found to fall naturally mto two groups. Nos. 11 to 20 were taken from large masses of quartz in pegmatite dikes and masses and in certain cases were definitely stated by the field relations to be the last portions of the pegmatite to crystallize out. In behavior they resemble vein quartz and have in all probability never been heated above the inversion temperature. From these specimens 11 to 20, 102 basal plates were cut and polished and etched; of these 35 were right-handed in circular polarization, 35 left: handed, and 20 intergrowths of right- and left-handed individuals, the out- lines of the different intergrowths being in general reoular and Wright and Larsen— Quartz as a Geologic Thermometer. 445 hexagonal in character; 380 were not twinned, while 58 were twinned and the outlines of the twinned areas were on the whole regular and indicative of hexagonal symmetry. The plates were as a rule-clear and free from fracture cracks.— The remaining eleven specimens of pegmatite were from pegmatites showing graphic intergrowths of quartz and feld- spar or coarse-grained avoregates of these minerals. The quartzes from these pegmatites accord in their behavior with original §-quartz later inverted to a-quartz. Of these 128 basal plates were cut and polished and etched ; 37 of which were of right-handed quartz, 81 of left- handed and 3 inter- growths of right- and left-handed individuals, the outlines of the intergrown areas being irregular; 31 plates were not twinned while 53 were twinned, the twinned areas being small and irregular in outline. The plates were in general much frac- tured and shattered.—Thirteen specimens of granites, granite gneisses and porphyries were examined and of these 89 plates cut, polished and etched; 34 plates showed right-handed rotatory polarization, 46 were left-handed while 3 were inter- growths of right- and left-handed individuals, the outline of the latter being on the whole fairly regular; 11 plates were not twinned, while 53 were intricately twinned, the boundaries of the twinned patches being small and irregular and without reference, so far as could be observed, to hexagonal symmetry. These plates were without exception small and traversed by fracture cracks which rendered it difficult to obtain satisfac- tory results from etching. The average diameter of the surface of the plates of vein quartz was 5"; of the quartz from the vein pegmatites, 7°"; of the quartz from the granite pegmatites, 2"; of the granite quartzes, 2™™. Summarizing these data still further, it may be stated that the quartzes from veins and geodes and certain vein pegmatites are in general clear and free from intricate fracture-cracks and show frequent regular intergrowths of right- and left-handed quartzes ; they are also frequently twinned after the unit prism and the outline of the twinned areas is usually regular and hexagonal in aspect. The quartzes from graphic and granite pegmatites, granites and porphyries, on the other hand, are smaller in size, frequently fractured and cracked in an intricate manner ; they show rarely intergrowths of right- and left- handed individuals and the outlines of such intergrowths may or may not be regular. They are as a rule intricately twinned and the twinned areas are usually small and irregular and bear no appareut relation in outline to the hexagonal symmetry.—The observed characteristics of the first group of quartzes are those deduced theoretically for low temperature a-quartzes, while the features recorded for the second group are essentially those 446 Wrightand Larsen— Quartz as a Geologic Thermometer. deduced theoretically for 6-quartzes formed above 575°. This places the temperature of final solidification of an intrusive granite mass above 575°. With the quartzes examined in the course of this investigation, a number of other minerals, garnet, magnetite, albite, lepidolite, etc., were associated, and in certain instances where, from the degree of idiomorphism and similar criteria, the relative periods of precipitation of the associated mineral can be ascertained, temperature limits of formation of the latter can thus be established. By thus determining stability ranges of certain minerals, points on the geologic thermometer scale are gained which in turn serve te fix limits for the temperatures of formation of other associated minerals. Summary. In the foregoing pages, attention is directed to a geologic thermometer scale the points for which are to be sought in the stability ranges of the different phases of rock-making minerais (their melting and inversion temperatures), and also in the melting temperatures of certain mineral aggregates (eutectics). (Quartz is well adapted to furnish at least one and possibly two points for the geologic thermometer scale, since on heating at 575° it suffers an enantiotropic change to a second phase, called 8-quartz by Miigge, while above 800° it is no longer stable at ordinary pressures, but passes into tridymite. Icllowing the example of Le Chatelier and Mallard, the point of inversion of a- and B-quartz was redetermined by observing the abrupt change in the birefringence, circular polarization and expansion — coefficient at that temperature. The most accurate optical determinations place this inversion temperature at 575° + 2°. Proofs that these represent an energy change were obtained by the perceptible variation in heat capacity in this region by the Frankenheim method of heating and cooling curves; and also by direct determination of the specific and latent heats in this region. Crystallographic proof of the change has been studied in detail by O. Miigge, who finds the high temperature phase, B-quartz, to be in all probability hexagonal and trapezohedral- hemihedral, while the low temperature a-quartz is hexago- nal and trapezohedrai-tetartohedral. This particular relation between the two phases entails certain consequences which can be used as eriteria to distinguish quartz which has been heated above 575° from quartz which has never reached that tempera- ture. These criteria were in large part indicated by O. Migge and have been applied above to a number of natural quartzes occurring in different kinds of rocks; the net result of the investigation being that vein and ygeode quartzes and certain large pegmatite quartz masses and pegmatite veins were formed Wright and Larsen— Quartz as a Geologic Thermometer. +447 below 575°, while graphic and granite pegmatites and granites and porphyry quartzes were in all probability formed above 575°. With the quartzes thus examined were associated other minerals, the order of precipitation of which relative to that of the quartz could be determined in certain instances and thus temperature limits for the formation of these in turn ascer- tained. The writers desire to express their indebtedness to Dr. A. L. Day for the precise thermoelectric measurements noted in the foregoing pages; to Dr. W. P. White for data on the specific and latent heats of quartz; and to Messrs. A. C. Spencer, E.S. Bastin, Arthur Keith, A. Knopf, Charles W. Wright, of. the U.S. Geological Survey, and Professor G. P. Merrill of the National Museum, for specimens of quartz from the localities cited in the descriptions above. Geophysical Laboratory, Carnegie Institution, - Washington, D. C.. March 4, 1909. 448 Gooch and Ward—Copper Oxalate in Analysis. Anne XR The Precipitation of Copper Oxalate in Analysis ; by F. A. Gooca and H. L. Warp. [Contributions from the Kent Chemical Laboratory of Yale Univ.—excix. ] Iv has been shown by Peters, in a paper from this laboratory on the volumetric estimation of copper as the oxalate,* that copper oxalate may be precipitated by oxalic acid with practical completeness from solutions of copper sulphate, provided the volume of the liquid is not too great and that the amount of copper present in solution exceeds a certain minimum value. It was shown that when the amount of copper present falls below a certain minimum either precipitation does not take place or it is incomplete. It was noted that the minimum was variable with the concentration of the precipitant, oxalic acid, and to some extent dependent upon the condition of the pre- cipitant, the minimum being smaller when the oxalic acid was added in crystalline form rather than in solution to the liquid containing the copper salt. Peters’ observations in respect to the effect, concentration and condition of the oxalic acid in solution of 50°™* are summarized in the following statement : Minimum amount of copper, taken as the sulphate, which must be present in order that nearly Amount of oxalic complete precipitation acid used. In Volume of may take place Crystalline solution liquid _grm. erm. erm. em?, 0°010 9) 5+ 50 0°025 2 3°95 50 0-040 1 Ee 50 0°050 0 Ee 50 + Saturated solution poured upon the copper salt dissolved in the least amount of water. It was also noted that when a saturated solution of oxalic acid, containing 0°1 erm. of oxalic acid to 1°™*, was slowly added to a drop of the copper solution containing 0:0003 grm. of cop- per the precipitated oxalate first formed dissolved completely in a volume of 5°"* of the precipitant. In the procedure for the quantitative determination of cop- per by precipitation as the oxalate, Peters recommends a volume of 50°™*, with 0°5 grm. to 2 grm. of crystallized oxalic acid as the pr ecipitant for 0°15 germ. of copper. An increase of the oxalic acid beyond this degree up to the point of saturation of the solution is apparently without effect. In subsequent work * This Journal, x, 359, 1900. Gooch and Ward—Copper Oxalate in Analysis. 449 involving separations Peters used volumes as high as 85°", of which concentrated nitric acid made up 5°, with 3 germ. of oxalie acid. With regard to the time required for completing the pre- cipitation, Peters showed that when no added nitric acid is present precipitates formed in the hot solutions at a volume of 50°" may be filtered, either at once or after cooling, without loss ; but that when the nitric acid is added the mixture must stand before filtration, best over night. The fact that small amounts of precipitated copper oxalate may be redissolved in a sufficient excess of the precipitant points to an appreciable degree of solubility of the precipitate in the solution of oxale acid. The observation that very considerable amounts of copper oxalate fail to come down at all until a certain minimum of the copper salt is present, while precipi- tation is nearly complete when that minimum is reached, indicates supersaturation of the precipitant by copper oxalate ; while the capacity of the liquid for supersaturation is appar- ently limited to some extent by increase in concentration of the oxalic acid. The solubility coetiicient of the copper oxalate under the conditions is made up, therefore, otf at least two factors, of which one depends upon the normal solubility in the solution of oxalic acid which constitutes the medium of pre- cipitation, while the other depends upon the solubility due to supersaturation. In order that small amounts of copper may be precipitated it is necessary to find means of eliminating or at least limiting the capacity of the medium for supersaturation ; and in order that large amounts, as well as small amounts, of copper may be determined with the highest degree of accuracy it is necessary to reduce to the lowest point the normal solu- bility of the oxalate under the conditions of precipitation. The present paper is an account of the experimental study of conditions under which small as well as large amounts of copper may be determined by the oxalate method. The Normal Solubility of Copper Oxalate. It is to be noted in the first place that the character of pre- cipitated copper oxalate depends upon the conditions of pre- cipitation. When oxalic acid is added to a cold concentrated solution of a salt of copper the copper oxalate precipitated is of extreme fineness and tends to pass through the closest filters. The precipitate formed in hot solution is, on the other hand, crystalline and easily separated by filtration of this liquid. The solubility of the precipitate, as well as the ease with which it may be separated from the liquid, turns upon the conditions of precipitation and treatment. In the experiments to be described, attention is first called to the degree of insolubility to 450 Gooch and Ward—Copper Oxalate in Analysis. be expected in the case of a precipitate formed by oxalic acid in hot aqueous solutions of neutral copper sulphate or copper nitrate and in amounts in excess of the precipitable minimum. In the experiments of which details are given in Table I, definite portions of a solution of the copper salt were diluted with water to the volume stated, heated to boiling, and treated with crystallized oxalic acid. After standing over night in contact with the solution, the precipitate was collected upon asbestos in a perforated crucible and washed carefully with small amounts of water. The erucible with its contents was placed in a beaker and covered with about 200%* of hot water containing 25°" of dilute sulphuric acid (1:4), and approxi- mately N/10 potassium permanganate of known standard was added to coloration. Pure copper sulphate was used for the experiments of A; and in those of B, copper nitrate, made by dissolving pure electrolytic copper in nitrate acid, evaporating off the excess of acid and dissolving in water, was used. The solutions of these salts were standardized electrolytically by the method of the rotating cathode.* The permanganate used in these and in all succeeding experiments was standardized against N/10 arsenious acid by acting with a measured volume of it upon a known amount of the standard arsenious acid, adding potassium iodide and titrating the excess of the arseni- ous acid in presence of acid potassium carbonate, by iodine also standardized against the arsenious acid, the difference between the arsenious acid taken and the arsenious acid deter- mined by the iodine being the measure of the value of the permanganate. Throughout the series of experiments, the error of the determination increases with the dilution. That the errors found in titration actually represent approximately losses in copper, at least for the smaller volumes, is shown by the difference, in two cases, between the result of titration and the electrolytic determination of copper in the filtrates from the precipitated oxalate. Fora volume of 10’, the average error in the titration of the oxalate precipitated, either from the solution of the sulphate or from a solution of the nitrate, is 0°0002 grm.; for 50° it is 00011 grm.; for 100, 0:0053 grm.; for 200", 0:0203 grm. For similar concentrations of the copper salt and of the oxalic acid the deficiency in the copper indicated by titration of the precipitated oxalate in- creases more rapidly than the dilution, a fact which suggests some specific action of water, perhaps hydration affecting the solubility or hydrolysis affecting the composition of the copper oxalate. That time and temperature are not essential factors * This Journal, xv, 320, 1903. Gooch and Ward—Copper Oxalate in Analysis. 451 Tape I. Effects of Concentration in Water Solution. Volume at Oxalic Copper precipi- acid Copper Average taken tation used found Error error erm. cm’, erm. erm. erm. germ. A Experiments with copper sulphate. 0°0100 10 0°5 0:0097 —0:0003 | 0°0100 10 0°5 0°0098 —0:0002 $+ 0:0002 0°0502 10 0°5 0°0500 —0°'0002 | 0°0502 50 2°0 0°0491 —0'0011 0°0502 50 2°0 0°0491 —0-0011 $+ 0:0012 0°0504 50 2°0 0'0491 —0°0013* | 0°0504 100 40 0:0468 —0:0036+ | 0°0502 100 4°0 0°0448 —0°0054 | 0°0502 100 5°0 0°0449 —0°0053 r Oreo? 0°0502 100 5°O 0°0437 —0°0065 J 0°0506 200 10:0 0:0303 —0°0208 0°0203 B Experiments with copper nitrate. 0°0455 10 0°5 0°0457 +0:0002 0°0002 0°0570 50 2°0 0°056 —0°0009 0°0009 0°0455 100° 50 0°0402 —0°0053 00056 0°0455 100 5°0 0°0395 —0°0060 * Copper determined electrolytically in filtrate = 0:0013 grm. + Copper determined electrolytically in filtrate = 0:0039 grm. in the precipitation of the oxalate, at moderate dilution from solutions of the neutral salt, was shown when Peters filtered, without appreciable loss, precipitates from 50°™* of hot solu- tion either at once and hot or as soon as the liquid had cooled. The experiments of Table IL show in addition that the precipitates, whether thrown down in hot solution or in cold solution, possess after long standing the same degree of insolu- bility. Taste II. Effects of Temperature at Precipitation and Titration after Standing Over Night. Copper | Oxalic Copper Precipi- Filtra- taken Volume acid found Error tation tion grm. em? grm. grm. germ. 0°0502 50 2°0 0°0491 0°0011 hot cold 0°0502 50 2°0 0°0492 0°0010 hot hot 0°0502 50 2°0 070490 0°0012 cold hot 0°0502 50 2°0 0°0491 0°0011 cold cold 452 Gooch and Ward—Copper Oxalate in Analysis. If any part of the apparent loss of copper oxalate precipi- tated from solutions of oxalic acid is due to hydrolysis of the normal oxalate, and formation of a basic oxalate as the produet of hydrolytic ‘action, it should be possible to obviate such apparent loss by increasing the active acidity of the solution and thus inhibiting hydrolysis, providing that the solubility of the normal oxalate is not made greater thereby. The experi- ment shows that beyond a reasonable degree of concentration — the results are not affected by the use of oxalic acid up to the point of saturation of the solution. It is worth while there- fore to look somewhat more carefully into the effect of stronger acids present at the time of precipitation. In Table III are shown the details of experiments in which the active acidity was increased by the addition of either free sulphuric acid or free nitric acid to the solution of the copper salt before precipitation was brought about by oxalic acid. These experi- ments were made under conditions otherwise similar to those of Table I. The copper sulphate was used in standard soln- tions. The copper nitrate was prepared in solution for each experiment by dissolving weighed electrolytic copper in nitric © acid, evaporating the solution to dryness, moistening the residue with a few drops of nitric acid and dissolving in water. A comparison of the results of Table III with the results of corresponding experiments in Table I brings out the facts that the apparent error is actually diminished by the presence of even very small amounts of sulphuric acid or nitric acid in the liquid, while, within reasonable limits, the addition of more acid produces no further effect. At the higher dilutrong) the effect of the active acid is marked. At a volume of 100% the average error of deficiency shown in Table I is cut in two by the addition of 071°" to 5™° of nitric acid) and ora ae gm* of sulphuric acid. At smaller volume of 50°™* the effect is not so marked, but it is still obvious. These results favor strongly the hy pothesis that copper oxalate is increasingly subject to hydrolysis as dilution increases, and that the tendency to form a basic salt may be checked by the presence of the stronger acids in suitable amounts. Even very large amounts of nitric acid produce a surprisingly small increase in the apparent solubility of the oxalate. : pee due to solubility of copper oxalate may evidently be kept at low limits by restricting the volume of the solution of oxalic acid in which precipitation takes place; but too much concentration is likely to introduce error due to mechanical inclusion of oxalic acid in the precipitates. The natural alternative to a close restriction of the volume of the aqueous solution is the limitation of the solvent power of a larger volume of liquid by partially substituting for water some other Gooch and Ward—Copper Oxalate in Analysis. 458 Taste III. The Effect of Active Acids. Volume of Volume Oxalic sulphuric Copper of the acid acidorof Copper Average taken liquid used nitric acid found Error error erm. em’, erm. em?. erm. erm. germ. A Volume at precipitation approximates 100 cm’*. H.S0, 070502 100 4°1) 0-1 0°0454 —0:0048 | 0°0502 100 4°0 0-5 00281 — 0-002) | 0°0502 100 4°0 1.) 0°0484 —0-0018 + —0:0024 0°0502 100 4°0 2°0 00474 —0-0028 | 0°0502 100 4°0 2°0 0:0481 —0-°0021 | HNO; 0°0515 100 4°0 Ol 0°0499 —0°0016 } 0°0530 100 4° O-l 0°0505° —0:0025 | 0°0502 100 4°0 Oral 0°0471 —0:00381 0°0502 100 4°0 O'l 0°0472 —0-:0030 0°0502 100 5°0 5°0 00471 —0:0031 \ _0:0031 0°0502 100 2°0 5°0 0°0468 —0:0034 0°1500 100 2-0 Oot 071476 —0°0024 0°2377 100 4°0 O°l 0°2356 —0°'0021 0°2530 100 4°0 Ol 0°2497 —0°0033 | 0°2897 100 4°() Ovl 0°2880 —0-0067 | B Volume at precipitation 50 cm’. 0°1333 50 4°0 O'l 0°1327 -—0-0006 } 0°1366 50 2:0 Her DAUBSOO.. =O OG | 0°1445 50 2°0 O'l 0°1434 —0-0009 + 0°2388 50 2°0 Ol 0°2384 —0°0004 | P0502 *.- - 50 2°0 4°0 0:0494 —0-0008 J 0°0504 50 4°) 2S OE SOU Mal) 0°0504 50 4:0 40:0 0°0487 —0°'0017 miscible liquid less capable of dissolving the precipitated oxalate. The experiments of Table IV were made to test the effect of alcohol as suggested by Gibbs.* The results given in A show the effects of aleohol without nitric acid; those of B show the effect of alcohol with nitric acid. It is plain that the presence of aleohol improves the results of the process as compared with the results obtained at similar dilutions of the oxalic acid solution, either with or without nitric acid; and, if the effect of nitric acid in the aqueous * This Journal, xliv, 214, 1867. Am. Jour. Sci.—FourtH SERIES, Vout. XX VII, No. 162.—Junz, 1909. 31 454 Gooch and Ward—Copper Oxalate in Analysis. Tape LV. The Lifect of Alcohol. Per cent of Volume alcohol Oxalic Nitric Copper of in acid acid Copper taken liquid liquid used present found Error erm. em, erm, em’, erm. A Precipitation in absence of nitric acid. 0.0502 100 20 1°0 ea 0°0492 —9°0010 0°0502 100 20 20 Ay ae 0°0491 —— OsGo ia 0°0502 100 40 2°0 pte 0°0491 —0°0011 0°0502 50 50 20 peneek 00499 —0°0008 0°0202 50 50 2°0 Dacron 0°0499 — 0°0008 B Nitric acid present in the liquid. 0°0502 100 20 1:0 5 0°0493 —0:°0009 0°0502 100 20 2°0 9) 0:0491 —0°0011 0°0502 100 40 4°Q 3) 0°0497 —0°0005 0°0502 50 40 2°0 2 0°0497 — 0°0005 solution is to prevent the formation of a basic salt, it would seem that the alcohol not only makes the precipitate more insoluble but checks hydrolytic action as well. Ina volume of 100™ containing 20 per cent of alcohol the error approxi- mates—0:0010 grm.; and for a volume of 50° containing 50 per cent alcohol the error is still negative though reduced to —0:0003. The effect of nitric acid accompanying the alcohol is not marked. In further experiments it was found that the addition of acetic acid, as proposed by Classen,* is even more effective than the use of aleohol, or of aleohol with nitric acid. In Table V are given the details of experiments in which the precipitation of copper oxalate was made in presence of con- siderable amounts of acetic acid. When considerable amounts of copper are present the precipitates formed in solutions con- taining acetic acid are apt to be very finely divided and conse- quently difficult to filter. A better condition of the precipitate is obtained, however, if, with the acetic acid, there is also present a moderate amount of nitric acid. The results of experiments in which both acetic acid and nitric acid were used are given in the table. The results of experiments in which sulphuric acid was present with acetic acid are also appended. From these results it is apparent that acetic acid when present to the amount of 25 per cent of the liquid produces in volumes * Ber. Dtsch. Chem. Gesellsch., x. b, 1816. Gooch and Ward Copper Oxalate in Analysis. 455 Tasiy V. The Liffect of Acetic Acid. Per cent Volume of Stronger Oxalic Copper of acetic acid acid Copper taken liquid acid used used found Krror erm. em?. em’, em: erm. erm, A Precipitation in presence of acetic acid. 0°0511 100 25 Lae 20 = 010502 —0:0009 0°0511 100 33 ters 2°0 0°0504 —(0'0007 0°0511 100 50 ask 4°0 0°0510 —0°0001 0°1533 100 510) me es 4°0 6'°1530 —(0°0008 : B Precipitation in presence of acetic acid and nitric acid. 0°0511 105 50 5) 4°0 0°0510 —0:0001 O-0511 110 50 Bas) ao) 4°0 0°0506 —0°0005 0°0511 100 50 10 4°0 0°0510 —0:0001 0°1530 100 50 10 4°0 Ow a29 ==) OUD! 0°1530 100 50 10 4°0 0°1530 —0°0000 C Precipitation in presence of acetic acid and sulphuric acid. 0°0511 100 50 D 2°0 0°0508 —0°'0008 0'0511 100 50 10 2°0 0°0413 — 00098 0°0511 100 50 10 4°0 0°0512 +0:°0001 0°0511 100 50 10 4°0 0°0513 + 90°0002 of 100° about the same effect as alcohol, and when present to the amount of 50 per cent it diminished still further the solvent power of the medium for the oxalate. The presence of nitric acid to 10 per cent of the entire volume does not materially affect the solubility. Sulphuric acid to 10 per cent of the volume of the liguid is without apparent effect upon the solubility of copper oxalate, provided the oxalic acid is also present in the proportion of 4 germ. to 100%* of the liquid. Treatment by oxalic acid in a medium consisting of acetic acid of half-strength, with or without nitric to the extent of 10 per cent by volume, is plainly the best of the procedures studied for the complete precipitation of copper oxalate in ideal condi tion; provided, however, that the copper is present in amount sufficient to break up the condition of supersaturation, let us say to the amount of 0°0500 erm. The Prevention of Supersaturation. Various means have been tried in the effort to break up supersaturation of the precipitating medium with small amounts 456 Gooch and Ward—Copper Oxalate in Analysis. of copper oxalate. Of these details an account is given below, in Table VI. The supersaturated solution (A) was frozen and the mass melted, following procedure which has been found to be success- | fulin hastening the deposition of small amounts of ammonium magnesium arsenate:* the supersaturated solution (B) was evaporated to dryness, and the residue extracted with water: alcohol was added (C) to the solution of the copper salt before attempting precipitation by oxalic acid: acetic acid of 50 per cent strength (D) was used asthe medium in which precipita- tion was attempted by oxalic acid. TABLE VI. The Precipitation of Small Amounts of Copper. Acetic Nitric Volume Aleohol acid at acid at Copper of Oxalic at pre- precipi- precipi- Copper taken liquid acid cipitation tation “ tation found Error erm. Gun, Cavin Chane, em?, em?. erm, erm. A The effect of freezing, melting and boiling. ORCC) Kreme Onna ORME me TPR a 2 ON none ies 0°0020 50 1:0 ee ives eit as 0°0005 —0°0015 0:0030 50 ILO) Beem Ema eledos 0°0024 —0°0006 0:0040 30 1°0 tae en Rae dis 0°0030 —0°0010 0°0050 30 ive) Sele lu eel 0°0039 —0°0011 0°0100 50 1°0 Wed 2 Sy Sea rae a: 0°0088 —0°0012 6°0200 50 1G aa ho a pe en ve 0°0188 —0:0012 0°0502 50 He) es oH es aa es ESS 0:0490 —0°0012 B The effect of evaporation to dryness and extraction of the residue with 50°™°. of water. — 0°0010 50 1°0 Beas areas Lots 0'0004 — 0°0006 0:°0020 10) 1:0 Se Ses ee 0:0018 —0°0002 0°0050 20 1:0 hs es Sie: Megat 0-00 2m —0°0008 ~ 0:0040 50 1°0 eee age Saas 0:0036 — 0°0004 0°0100 50 10 ie LY Sines 0:0095 —0'0005 0°0200 50 1:0 apee ae cae 0°0196 —0°0004 0°0502 50 10 ces eae bee ehh 4 0°0499 —0°0005 C The effect of precipitation in 50 per cent alcohol. 0°0010 50 2°0 45) Ee Sap ae none Ames 0°0020 50 2-0 745) Shubin ON none tat 0°00380 50 2°0 DS ene ee 0°0015 —0°0015 0°0040 50 2°() 29 pe a 0°0020 —0°0020 0'0050 50 2°0 25 ae 2 Set aes 0°0016 —0'0034 0°0100 50 2°0 25 Ne Se ak OLO 0 S9 —(0)°0015 0°0200 50 2°0 25 Sey ae 0°01 98 — 0°0002 0'0502 50 2-0) 25 Mbp Bane 0°0499 —0:00038 * Gooch and Phelps, this Journal, xxii, 488, 1906. Gooch and Ward—Copper Oxalate in Analysis. 457 TaBLE VI (continued). The Precipitation of Small Amounts of Copper. Acetic Nitric Volume Alecobol acid at acid at . Copper of Oxalic at precip- precip- precip- Copper taken liquid acid itation itation itation found Error erm. cme. erm. em’, eme cnr. grm. erm. D The effect of precipitation in acetic acid. Volume 50°" : 50 per cent acetic acid. 0°0010 50 2 ciate i 25 eer OcO0 10 0°0000 0°0020 50 2 eas 25 ee OnOO2 i +0:0001 0°0031 50 2 Soatce 25 ee OLOOI —0:0004* 00041 50 2 geet. 25 fee 00041 0:0000* .. 0:0051 ae ne Se 2D eee 0049 —0:0002* 0°0102 50 2 Eph 25 Pee OOOO S —0:0004* 0°0204 50 2 ied Uh Gees OU EE — 0:0006* 0°0511 50 2 eae 25 Eyer ae hat ne 0°0010 50 2 fee 25 9) 0°0010 0°0000 0°0020 50 2 our 25 5) 0:0021 +0°0001 0:0031 50 2 se 25 5) 0°0033 + 0:0002 0°0041 50 2 zeta 25 5 0°0042 +0°0001 P0051 -50 2 tee 25 5 00043 —0°0002 0°0102 50 2 oe: 2X 25 5 0°0108 +0°0001 0°0204 50 Y Brahe? 25 5 0°0204 +0 '0000 0°0511 50 2 Eile 25 5) 0°0512 +0°0001 Volume 100°™? : 50 per cent acetic acid. 0°0010 100 = Seas 50 3 0°0010 0-0000f 0°0020 100 4 Feet 50 3 0:0021 + 0°0001f | 9°0031 100 4 eRe 50 5 0:0031 0-0000 0°0041 100 4 ee 50 5 0°0041 0:0000 . 00051 100 4 See eo 0 eo =, Or00n h +0:0002 0°0102 100 + Lie a 50 5 0°0103 +0°0001 0°0204 #100 + a oa 50 5 0°0196 — 0:0008§ 0°0511 100 ~ BE 50 5 0°0510 —0:'0001 : Volume 150 : two-thirds acetic acid. 0°0010 150 = Ey cke TO Om ese SOLO Oma: + 0:°0005 0°0010 150 + Eee 100 5 0°0012 +0:0002 * Filtration imperfect. + Filtration impossible. t Precipitation formed slowly. _ § Filtration imperfect. _ From these results it appears, first, that by precipitating at a volume of 50™, freezing, melting, and boiling, the condition of supersaturation may be broken up, the oxalate obtained being soluble in the proportion of about 0-0011 grm. to 50°%™ of liquid ; secondly, that by precipitation at a volume of 50°™*, evaporation to dryness, and extraction with the same volume of water, the copper may be recovered to an amount within 458 Gooch and Ward—Copper Oxalate in Analysis. about 0:0004 grm. of that taken; thirdly, that treatment by oxalic acid in 50 per cent alcohol fails to precipitate about 0:0020 grm. of copper from amounts less than 0°0200 grm., while for amounts exceeding that limit the copper is nearly all recovered ; and, fourthly, that in volumes of 50°” or 100°, consisting of 50 per cent acetic acid, the copper oxalate is thrown down completely, the presence of nitric acid to the extent of 10 per cent making the filtration more effective with- out influencing the solubility, while at a volume of 150° the precipitation is complete provided the acetic acid makes up two-thirds of the volume. The best and most convenient procedure for the precipitation of small amounts as well as large amounts of copper oxalate ideal in composition consists, therefore, in adding 2 grm. or 4 erm. of oxalic acid to 50°™* or 100°", respectively, of the 50 per cent acetic acid solution of the copper salt containing 5 per cent to 10 per cent of nitricacid. The permanganate titra- tion of the washed oxalate, in presence of sulphuric acid, gives very accurate determinations of the copper. E. Blackwelder— Yakutat Coastal Plain of Alaska. 459 Art. XL.—The Yakutat Coastal Plain of Alasku:* A combined terrestrial and marine Formation; by Extor BLACKWELDER. Tue reconstruction of the climatic, physiographic and _ bio- logic conditions of past ages has long been one of the chief objects of geologic study. Many lines of search have been pursued with various degrees of success. Some facts have been deduced from the fossils, others from the constitution of the atmosphere, and still others from the rocks themselves. Like most other questions, these have been investigated now with caution and a full realization of the complexity and uncertainty of the factors, and now with easy confidence and blindness to difficulties. Some interpretations of sedimentary deposits made in an off-hand way have been little better than guesses. An encouraging number of others, however, are firmly based so far as they go, and, best of all, the facts and inferences are duly separated. In the interpretation of the older sedimentary rock forma- tions we have to deal with what may be called fossil products of aggradation. There are two ways in which one may approach a given problem of this sort: (a) having studied the many facts carefully, we may reason out, from our knowledge of physiographic, climatic and biologic principles, what conditions must have prevailed at that time and place; or (b) we may compare the fossil deposit with various modern deposits of known origin and decide to which of them it corresponds. Both of these methods are used and often in combination. In order to put the second into practice it is necessary for us to know intimately the characteristics of many modern deposits, and also all the conditions under the influence of which those deposits are now being made. The careful description of modern formations in many parts of the world is, therefore, essential to progress in this study, and this paper is presented as a small contribution to the mass of information needed. From near the mouth of the Alsek River to Controller Bay, the southern coast of Alaska is fringed by a narrow plain. From Yakutat Bay westward it is partly covered by the Malaspina piedmont glacier. The part with which I am familiar is that between Yakutat and the Alsek River. Ocean- ward the plain dips beneath the water level, leaving a tolerably regular shore line. On the north it is hemmed in by the Bra- bazon range, the front of which rises abruptly 2000-4000 feet without either foothills or fringing talus-slopes. * Published by permission of the Director, U. S. Geological Survey. 460 F. Blackwelder— Yakutat Coastal Plain o Alaska. The climate of the coast is humid and cool, with compara- tively slight temperature changes. Winds roll in from the Tien ahs GRAVEL ALSEK R, sc) = ae © N >: { & 0 Ke) — : [24 e g ae A ale ag) a Sand —Zone MARINE Sabie itis a ez << Fic. 1. The coastal plain from Yakutat Bay east to the Alsek River. Shows roughly the distribution of modern sediments. (Compiled from maps and notes by Maddren, Brabazon, Netland and others.) E. Blackwelder— Yakutat Coastal Plain of Aluska. 461 warm Pacific ocean and keep the mountains enveloped in nimbus clouds for days at a time, with only occasional sunny intervals. Showers and fogs are of frequent occurrence. The climate in summer has, therefore, been aptly characterized as “damp and chilly.” In winter the snowfall is heavy, but the freezing of both soil and streams checks the operation of the processes we have to consider. Under the influence of this climate a dense growth of boreal vegetation covers the plain. On tie flat undrained parts, grassy marshes and willow swamps prevail. On moraines, sandy ridges, and, in fact, wherever the soil is subject to drain- age, there are dense spruce forests with a dank undergrowth of. mosses, ferns and ‘“ devils-club.” Everything there is soggy, even on the drier days. Needless to say the rivers are permanent and brimming, although subject to fluctuations according as the rains are heavy or light. All but the Alsek are short streams, but some even of these rise in the abundant glaciers which choke the mountain valleys. The glacial rivers are swift, and are milky with fine sediment; but the others, which draw their water through many swamps and lakes, are clear. In the history of the plain the glacial:streams are probably of far more import- ance than the others. The rivers which cross the plain are engaged in aggrading. They have no valleys, and their immediate channels are sunk but a few feet beneath the plain.” Having this picture of the district and its conditions, we may now consider the structure and composition of the plain itself. The foreland is composed entirely of unconsolidated Quaternary sediments. Near Yakutat Bay, and subordinately elsewhere, low glacial moraines make the surface The rest of the material was deposited by water or wind, and is stratified. The plain seems to have been built out into the ocean by shifting aggrading rivers. These rivers are swiftest near the mountains and become slack at tide-level. On this account the sediments are graded in coarseness. Near the mountains, coarse gravel predominates; but as one passes seaward he may trace the gravel into sand and finally into silt. This zonal arrangement of gravel, sand and silt probably persists roughly with depth, for the conditions of gradient have doubtless been similar through much of the history of the plain. In com position the sediments have certain distinctive fea- tures. The colors are limited to black and grays of various intensities. Tinges of green are not uncommon but are faint. When examined “closely the sediments are found to consist of * The work of these streams as seen in front of the Malaspina glacier has recently been described by Tarr, Zeitschrift fir Gletscherkunde, iii, 88-95. 462. Blackwelder— Yakutat Coastal Plain of Alaska. particles of slate, greenstone, quartz, feldspar and ferromag- nesian minerals, with a varying admixture of carbonaceous material. A lack of the usual products of oxidation is the striking characteristic of all the deposits. In general the sediments do not show evidence of long con- tinued attrition. Although the pebbles and sand grains are inoderately round, many particles are angular or irregular in Jey, Bi Fic. 2. The delta of the Alsek River as seen from the Brabazon Range on the north. A type of the constructing rivers of the foreland (photograph by Netland, U. 8. Boundary Survey). shape. The assortment and segregation of the particles, both as to size and lithologie character, is also markedly imperfect. The gravels are heterogeneous mixtures of bits of slate, gray- wacke, granite and other rocks. The sands contain feldspar, magnetite, hornblende and slate in addition to the usual quartz. In the matter of size also the same lack of assortment pre- vails, large pebbles and small being bound together by a matrix of muddy sand; while the silty beds contain much sand and mica. Heterogeneity is therefore another distinguishing prop- erty of these sediments. Upon the surface, the distribution of the various deposits is determined by their origin. At the mouths of the largest valleys there are glacial moraines. Along the more powerful streams there are sheets of bare gravel and mixed sands. In the swampy intervening areas peaty material is accumulating. Along the ocean beach, exposed to the storm waves and high winds, pure quartz-sands are being heaped into low dunes; while in the tidal lagoons and estuaries just back of the shore, E. Blackwelder— Yakutat Coastal Plain of Alaska. 463 sticky mud forms the bottom. Although we can not see what is being deposited on the bed of the ocean, yet we need not doubt that the ceaseless milling of the breakers and currents is comminuting the sediment and distributing the different kinds of detritus in belts varying with the depth of the water and the exposure. This part of the formation should be well assorted and the individual deposits of sand and mud _ tolerably homogeneous in composition and texture. For a picture of the gross structure of the beds we can not rely upon actual observation, for there are no sections which expose more than a few feet of the deposits. But from the nature of the agents engaged in building the plain we may infer with confidence that the structure is complex. The MiGeeor BRABAZONY PAC/FIC OCEAN i ——— i — a a ee ——_ + : SS ————— ea a ee ww Fe et tw tees Fic. 3. Ideal cross-section of the foreland, showing the relations of the different kinds of sediments. Vertical scale exaggerated. (The eross-lined pattern denotes moraines.) glaciers have probably been subject to advance and retreat, as all well-known glaciers are, and, if this is true, they have left sheets of till between beds of gravel. The streams are bor- dered by gravel wastes through which old stumps protrude,— remnants of forests invaded by the rivers. These and other facts show that the rivers are constantly changing their courses so that river gravels are interlaminated with peaty layers made in bogs and forests. It has been said that the larger rivers are subject to marked fluctuations in volume. In time of flood gravel is spread far out over the sands, and at low-water stages such sheets of gravel are again covered by sandy beds. As these changes recur frequently, the sediments must consist of rapidly alternating coarse and fine beds. The coast line itself must be subject to shifting ; for even if there have been no changes of level the plain must have been built out into the ocean. If, on the other hand, this is a region of tectonic disturbance, as shown by Tarr and Martin,* then we should expect to find yellow dune sands, gray estuarine clays and *R.S. Tarr and Lawrence Martin, Recent changes of level in the Yakutat Bay region, Alaska: Bnll. Geol. Soc. Amer., xvii, 29-64, 1906. 464 fF. Blackwelder— Yakutat Coastal Plas of Alaska. mixed fluviatile deposits lying one upon the other and perhaps alternating in successive wedge-shaped beds. The stratification planes of the various classes of deposits have peculiarities of importance, and these surface features are in turn reflected in the minor structures seen in cross-section. The aggrading streams are all filled with fan-shaped bars which have gentle back slopes and steep outer slopes. The depo- sition of sediment in this form produces prominent cross- bedding. More intricate cross-bedding is caused by the alter- nate cut and fill of the shifting rivers and by the migrating sand dunes. Cross-bedding is also doubtless acommon feature of the deposits now forming near the zone of breakers in the ocean. On the whole, therefore, much of the deposits of the foreland must be cross-bedded. Ripple-marks, although absent in the deposits of the swamps and quiet lagoons, are characteristic of the beach and river sediments. On the ocean shore, regular ripple-marks of the long parallel type are made by the water currents below tide- mark and by the wind currents above that line. In the chan- nels of the streams the ripple-marks are usually shorter and of the spatulate type, with gentle back slopes and steep fronts. They are even more numerous there than along the littoral zone. Some which were observed by our party near the head of the Alsek delta were exceedingly large. These were composed of bowlders and coarse gravel and had a relief of 4 to 6 feet with wave-lengths of scores of feet. In fact they were so large that I did not recognize their true character while clambering over them, but only when I saw them in panorama from a considerable elevation. Ripple- marks of such magnitude would of course express themselves in cross-section as strong cross-bedding. They give some idea of the power of the current in the Alsek River when it is in full flood. Sun-eracks, another feature of terrestrial and tide-water sediments, appear to be uncommon here. I do not remember having seen any. The explanation is doubtless to be sought in the climate, which is so moist that muds rarely become dry enough to crack. If the cracks occur anywhere, the tidal sounds would furnish the most favorable conditions. Organic remains are being preserved between some of the layers to-day and they offer a further means of identification of deposits of this general class. In the submarine zone of the plain, shells of mollusks, echinoderms and other aquatic animals lie upon the bottom; but as life is not very abundant in this boreal sea, the shells preserved should be somewhat scarce. In the terrestrial zone, driftwood is buried by the dune sand, while forest trees are undermined by the rivers and enveloped in deposits ef gravel or sand. In the finer sedi- E.. Blackwelder— ¥ akutat Coastal Plain of Alaska. 465 ments of swamps and estuaries, leaves of ferns and other plants find lodgment and are doubtless being preserved. Animal re- -mains, on the other hand, arerarer. Bones of salmon are buried in the river sediments in some quantity, for millions of them die each year on the spawning grounds; but, since they frequent chiefly the gravelly bottoms, their opportunities for preserva- tion are not the best. Land mammals are too scarce on the plain to leave many skeletons. It thus appears that fossils must be tolerably rare in the entire series of beds. In the marine portion plants would be deficient, while mollusks, crus- taceans, worms and echinoderms would predominate. In the terrestrial part, bits of wood and even leaves would be locally abundant, but animal remains would be rare and coiprise little but the fishes. The characteristics of the sediments in the Yakutat plain may be summarized as follows 1. Origin: partly terrestrial and partly marine, the phases either interleaved near the contact or the one transgressing upon ene7other.. °™ Types of sediments : till, gravel, sand, silt, mud, and peat. 3. Composition : heterogeneous. 4. Color: gray to black, due to the lack of oxidation products and the abundance of carbonaceous matter. 5. Texture: subangular as well as round particles, alternately finer and coarser. 6. Assortment : very imperfect except in the marine phase. Fragments of many rocks of many sizes intermingled con- fusedly 7. Stratification : complex and irregular in the terrestrial phases. Cross-bedding, lense-structure and ripple-marks prevalent in the sandy beds. Effects of contemporaneous erosion com- mon. Sun-cracks rare. 8. Fossils: in the terrestrial portion leaves and wood common, animals rare (chiefly fishes). In the marine portion shells fairly common, plants rare. ad Although my subject is the modern sediments of the plain, I may call attention here to the interesting fact that these sedi- ments have analogs in the hard rocks of the mountains behind them. The Brabazon range and the Puget peninsula are composed largely of the Yakutat series,* which has been refer- red to both the Carboniferous and the Jurassic systems. This formation presents clearly many, although not all, of the charac- teristics of the sediments in the plain just described. The rocks are black slates, dark graywackes and conglomerates. * The lithology of the beds is described in many papers, among them the following: Harriman Alaska Exped. Report, iv, pp. 44-56; I. C. Russell, Nat. Geogr. Mag. , lii, 166-170; U.S. Grant, U. S. Geol. Surv. Bull. 284, p. 79-80 (Orca series). — 466 F. Blackwelder— Yakutat Coastal Plain of Alaska. They consist of many materials, usually poorly assorted, and often imperfectly rounded. The minerals are not oxidized, and carbonaceous material is abundant. Conglomerates are interleaved with graywackes at any horizons. Ripple-marks and eross-bedding are found in the coarser beds. Fossils are very rare, and of those discovered the commonest may perhaps be plant stems or worm trails. Only a single identifiable shell has been found* and that not in this vicinity. There are even beds suggestive of glacial action.t I interpret this to mean that, at a much earlier time, this part of the Alaskan coast had much the same cool, rainy climate that it has to-day, that it was bordered by a growing foreland covered with dense vegetation and was backed by rugged highlands ; Russellt describes a series of rocks, younger than the Yakutat formation, which he found on the slopes of the St. Elias range and named the Pinnacle series. This comprises 1800 feet of dark gray sandstone and shale with beds of conglomerate. Some of the beds contain marine shells ; others have coal seams. Here again there is a lack of oxidation products and an alter- nation of dark clastic sediments suggestive of the modern coastal deposits. In one of the coarse conglomerates of the Yakutat series I observed a bowlder, itself composed of an older conglomerate, and among the pebbles in the latter were hard quartzitic gray- wackes of the same unoxidized carbonaceous character. That this represents a still earlier epoch of similar conditions is at least suggested. Taken together, these facts seem to indicate that certain climatic and physiographic conditions have recurred at widely separated intervals in this single region. In each case the record is purely sedimentary rather than paleontological. University of Wisconsin, March 1, 1909. * ©. O. Ulrich, Harriman Alaska Exped. Rep., iv, pp. 125-148. + Eliot Blackwelder, Jour. of Geol., xv, p. 11-14. The probable glacial origin of certain folded slates in southern Alaska, 1907. t Loe. cit. p. 170-178. A. F. Rogers— Pyrite Crystals from Bingham, Utah. 467 Art. XLI.— Pyrite Crystals from Bingham, Utah; by Austin F. Rogers. Tue pyrite crystals described in this note were kindly pre- sented to the writer by Dr. A. L. Inglesby of Bingham, Utah. They were obtained by him from the Highland Boy mine in Carr Fork, about a mile and a half above Bingham. The erystals, which average about 5"" in diameter, are well developed, have brilliant faces, and are often highly moditied. The best groups of crystals.in Dr. Inglesby’s collection are magnificent specimens, rivaling those from Leadville and from Central City, Colorado, in attractiveness. The observed forms are as follows : cube, a@}100;; pyrito- hedrons, ¢{210}, @{430{, 6/610}; trapezohedrons, ni2ilt, m {311}, 4) 411}; positive diploids, ${3821', 6{12°9-1t, p{10°7-1}: negative diploids, {8-105} and O}3871}. Of these the last four are new for the nanesd pyrite. The habit is determined either by the cube or by the pyrito- hedron {210}, often in about equal development. No tendency toward an octahedral habit was noticed :—a@}100}{ varies from a mere line face to the dominant form. It is often striated parallel to its intersection-edge with j111{; ¢{210} is on most of the crystals the dominant form. It is sometimes striated parallel to its intersection edge with $111! and 3821} and only rarely vertically striated, 0} 111} is present on all the crystals and sometimes prominent. Its faces are bright and usually marked by concentric triangles which represent oscillations in the zone of trapezohedrons ; s/321{ is present on many of the crystals ; ; ni211' occurs on every erga and is often rather prominent; 7} B11} and w}411} are subordinate forms present on about half the onsale m\311* is the more frequent of the two and usually the larger; 6/610: and 6{480} are the only pyritohedrons in addition to 210%. They are narrow and unimportant forms. Each of the new forms is present on several crystals and they are well established by measurements. {12°9'1; is ina vertical zone with {480!. p{10-7 1§ is near }12°9°1{ in position but is sharply defined. T}8°10°5 is a negative diploid in the vertical zone with [210: 211: 213] and hence only one measure- ment was necessary for its identification. O{371} is present on several crystals. Its faces are striated and apparently there is a (570) face. Measurements in the cube and ae zone give an image for the (370) position, but in the [371: 371] zone there were multiple images but no definite one for (370). This example, it is thought, shows an hdvantage of one-circle measurements over two-circle measurements. 468 A. FE. Rogers—Pyrite Crystals from Bingham, Utah. The. following is a list of combinations and habits, the forms under each being arranged according to their prominence. The list begins with dominant cubic habit and ends with dominant pyritohedral habit. Le OEAM 8. CHON MSY OO Ghmp (see fig. 1). 2. aeon 9, eaonms OO 3. aeonmsp O 10. eaons 4. GENSOMp 1l. eoan Om od. GEON 12. eoansm 6. Geondp 13. eonm 7. eanosmpoppY 14. €on Data for the identification of the new forms are given in the following comparison of the measured with the calculated angles : Cryst. 7 Cryst. 8 Cryst. 11 Calculated 1128s 11os3 fe Tee 112305 44 LIke cree 17-42 AS ein Ua ee eee 3 49 ily Reet BEIT SOR Paes 147 58h 14 58 BA Feo clematis eagle naam 9 388 BD eM R CU Reta eens ae 33 334 Fig. 1 represents crystal No. 8. This gives a general idea of the average habit and shows three of the four new forms. This figure is simply a sketch inked in with a straight edge and not the regulation clinographic projection. In addition to the forms charac- teristic for this locality, the most remarkable feature of these crystals is the prominence of the zone [100: 411: 311: 211: 111]. This is shown not only by the presence of the three trapezohedrons indicated but also by oscillatory striations on the octahedron faces and occasionally on the cube faces. The poverty of pyritohedrons is also striking, there being but two pyritohedrons besides }210{. This is also sub- stantiated by the fact that vertical striations rarely occur either on the cube or on the pyritohedron } 210}. Stanford University, Feb., 1909. Maas 0: G. P. Merrill—Composition of Stony Meteorites. 469 Arr. XLIL.—TZhe Composition of Stony Meteorites com- pared with that of Terrestrial Lgneous Rocks, and con- sidered with reference to their efficacy im World-Making ; by Grorce P. Merritt. [Read before the Geological Society of Washington, March 24, 1909, | SPECULATION relative to subjects the actual proof of which lies entirely beyond his reach, has ever been a favorite pursuit of the thinking man. Nowhere is this more manifest than in questions relating to the age and origin of the earth. Of all the theories which have been evolved, and which have stood the test of any considerable length of time, only that known as the Kant-Laplacean, and the more recent hypotheses of Professor Chamberlin of Chicago, need our present considera- tion. Any and all of these call for the world-making materials, whether gaseous or solid, from sources beyond our immediate universe. It is but natural, therefore, that those substances which reach our earth from space in a solid form, and which give the only really tangible illustrations of what materials of space may be, should be regarded as of value in aiding our arrival at the desired conclusions. This fact was recognized over one hundred years ago (179+) by Chladni, who regarded meteorites as remnants of cosmic materials employed in the formation of worlds, or, as he expressed it, as “Weltspine.” The idea, with various more or less important modifications, has been repeated by subsequent workers,* and is brought up for consideration with renewed force by the recent papers of Professor Chamberlin, which have been so clearly summarized — under the heading of the “Origin of the Earth” in his work on geology.t It should be stated, however, that Professor Chamberlin is not an advocate of the meteoric theory of the earth; in fact, he states definitely that the origin of meteorites is but an incidental result of stellar and planetary action, their genesis being wholly a secondary matter, and furnishing no grounds for regarding them as the parent material of great nebule or of stellar systems. Chamberlin inclines rather to what he calls the ‘“‘planetesimal hypothesis,’ which assumes that the solar system was derived from a spiral nebula consisting of finely divided solid or liquid materials, which revolve independently about a common nucleus, and which are gathered into larger aggregates through the crossing of the elliptical orbits of the * See Lockyer’s Meteoric Hypothesis for discussion. Arrhenius’ Worlds in Their Making is perhaps the latest work in which the matter is seriously considered. t Geology, vol. ii, Earth History, pp. 1-81. Am. Jour. Sci.—FourtH SERIES, Vout. XX VII, No. 162.—Junz, 1909. : 32 470 G. P. Merrili— Composition of Stony Meteorites. individual members. It is obvious, however, that whatever theory is adopted,—the Laplacean, meteoric, or the planetesi- mal—the kind of material, and presumably the ultimate origin of all, remains the same. It is this thought which has led me to enter upon the present discussion. Meteorites as they come to our earth, as is well known, are roughly grouped into three general classes ; first, those which consist essentially of nickeliferous iron nearly or quite devoid of silicate material; second, those which consist of a spongy mass of iron, including elobular ageregates of silicates ; and third, those which are nearly or quite all of silicate material, with more or less sporadic iron. These forms, it is true, orade into one another, but, nevertheless, the classification is much easier than one would be at first led to suppose. Researches into the composition of our earth have led us to assume that it is composed of an outer zone of comparatively rich silicate material, in which free silica is an important con- stituent, and an inner zone of material which is essentially metallic, with perhaps an intermediate zone showing a transi- tion between the two extremes. Regarding meteorites as world materials, as has been done by certain workers, we might consider the purely metallic varieties as representing the deep-seated, probably nucleal, material of some pre-existing planetary body; the stony meteorites as representing the crustal material; and the spongy irons with the mixed silicates (pallasites) as representing the intermediate portion. The fact, however, that a part, at least, of the iron of stony mete- orites has been repeatedly shown to be of secondary origin— to result from the reduction of some compound subsequent to the consolidation of the silicates, is difficult to harmonize with any such view. Inasmuch as the nucleal material of fe earth is quite beyond reach for purposes of investigation, and as the intermediate zone, if such there be, is represented, if atall , only by extrusions of deep- seated igneous rocks, I have for the time being limited my considerations to a comparison of the stony meteorites with the great group of igneous rocks as existing to-day upon the earth’s surface. It will be seen at once that in doing this, I have accepted for the purpose the most acid group of the ultra-terrestrial rocks There are many difficulties in the way of obtaining anything like an accurate average of the composition of these materials. This, for reasons which can be fully appreciated only by those who have attempted their study, and more particularly, the making of chemical analyses. One of the chief ditticnlties, it may be said, les in the separation of the metallic from the non-metallic portion, The method of statement of the results, G. P. Merrill—Composition of Stony Meteorites. 471 and the proper interpretation to be put upon the same, add to the difficulties. Several of the constituents, moreover, occur in such extremely small quantities, or like the chloride of iron (lawrencite), undergo such rapid deterioration, that their deter- mination has been largely overlooked, particularly in the older analyses. Or, again, if such determinations were made, the results as given are at least open to doubt in the ight of more recent investigations. In going over all of the hterature available, | have found but ninety-nine analyses which were made, as it seemed to me, with sufficient care, were sufficiently complete, or stated in such a way as to render the results com- parable with one another. Even in these ninety-nine, all of the constituents were not determined, and in many instances, where the presence or absence of a certain element was not stated, one is left in doubt as to whether such was looked for, or whether it was looked for and found lacking. Out of the ninety-nine analyses, however, silica, alumina, iron, ferrous oxide, hme, magnesia, potash and soda were found determined in a sufficient number of cases to make the matter of an aver- age a fairly safe approximation, the metallic iron affording the most difficulty. Of the remaining constituents, as given in the table below (No. 1), the manganese is an average of forty-one determinations, the phosphorus of thirty-one, the chromic iron of sixty-seven, the sulphur of ninety-two, and the nickel-cobalt of ninety-three. The percentage amount of sulphur has, in many cases, been arrived at by calculation, since the results Average composition of stony meteorites as calculated from 99 analyses for all constituents but P, which is from 31 determinations; MnO from 41 determinations, Cr.0;+Fe.0; from 67 determinations ; Ni,Co from 93 determinations; and § from 92 determinations. I UI Average of Recalculated on Results as given basis of 100 SG es a ae 38°98 38°732 MOOD 2 pee SG 2°75 2°733 LING a ine eae EEG 11°536 15 Os zaiien eer mer 16°54 16°435 Ci@yats ee Lory 1°758 NR Oe 2808 22°884 INGOs oe 2 et ow SOLOS 0-945 We Oger ae O88 0°328 Cr,O,+Fe,O, --- 0°84 Av. of 67 dets. 0°835 i © oye tee 1°32 cae ned ayer 1°312 ie Re ee 1°85: Se Ow aide 1°839 | a Ee Otte Reine Okt Bo pecanle 0°109 NEA a 0°56 eo ee ANS NS 0°556 100°64 100°00 472 G. P. Merrill—Composition of Stony Meteorites. were sometimes given as simply ferrous sulphide and some- times as sulphur. Where such calculations were necessary, the percentage of iron was added to the amount given in the analyses as existing in the metallic state.* The following list shows the highest and lowest percentages of any given constituent in the analyses here aver aged. Highest Lowest BiGie tue as 61:15 26°05 Al.O, ths Ss neh le, 0°00 Wen eos ar ee 7 OO 0:00 HeO: 2 eas Ord 0°99 CAO Mine ores 7°03 0:00 MgO es News 9 ae 39°04 = 6°44 Na,O ROME AA tea aaa iene 3°94 0:00 K,O . Bh tslgs se Hila oat 4°31 + 0°00 Cr 2OF +Fe, ©. oOo e 0°00 NiCo be Mt ea eat sc 4°21 0:00 No eee es Pract oO TAT 0-00 +It would seem that this must be an error, since the stone (that of Zsadany, Hungary) is described as consisting essentially of olivine and pyroxene, and no reference made to feldspars. For comparison of these results with terrestrial rocks, the following are given: Average composition of terrestrial igneous rocks as calculated by (III) Clarke and (IV) Washington.} Ii IV DIO er See eee 60°91 58°239 RIO yeas oe = los 15-796 Hie G) een sist peai 2 63 3°334 ReO ene ae Se Ol6 ; 3°874 Mis Op oes so. 4 lis 3°843 CaO” taser ms 4°88 5:22] INGOT SE Sephora: 3°45 3°912 KOM Sohn ae emeE oe 3°16] 1,0 ab VOO; se 041 0°363 “ above 100° 1:49 1428 iO. ene eae 0°73 1:039 FO- cep eee 0°26 0°373 10061 100°583 + Bull. 380, U. S. Geol. Survey, 1908. * The writer regards these results as only approximations, and suggestive. The recalculation of many of the analyses‘s attended with so many uncertain- ties, that it is even probable that slightly different results would be obtained in going over the same ground a second time. So far as the main constitu- ents—the silica, alumina, lime, magnesia, potash and soda—are concerned, he believes the averages as good as can be obtained with available material. en G. P. Merrill — Composition of Stony Meteorites. 473 Tt may be well to add that the approximate weight, so far as known, of all the stones represented by these ninety-nine analyses, was 4,014 kilograms or about 4:4 metric tons. An average of 77 determinations, as given, of specific gravities gave 3°51, of which the lowest, that of the Orgueil, France, carbonaceous stone was 2: 50, and the highest, that of Limerick, Treland, 3°92. It will at once be noted that there is a wide and striking difference in composition between the meteorites and the ter- restrial rocks,—a difference not merely in the relative propor- tion of the various elements, but also, in one case at least, in their method of combination. The most striking feature is, for the meteorites (columns I and II), the low silica content, and the high percentage of metallic iron, ferrous oxide, and magnesia, with the corresponding low percentages of alumina, lime, and the alkalies.* Compared with Washington’s averages for terrestrial rocks, it will be noted that there is a difference of nearly twenty per cent in the amount of silica in favor of the latter, and of some thirteen per cent in the amount of alumina. These differences are so striking that they cannot be considered as due to errors of analyses, or of their inter- pretation. They must be fundamental. Should we disregard entirely the metallic iron of the meteor- ites with its included nickel, cobalt, and phosphorus, and also the iron disulphide (amounting all together to 14°79 per cent), and recalculate Analyses II on the basis of 100, we get the results shown in column V below. In column VI is given the average of seven analyses of terrestrial peridotites+ which, as will be at once apparent to the petrographer, afford the closest approximation, in chemical as well as mineral composi- tion, to meteorites. These, it should be stated, have been recalculated on a water-free basis. It is scarcely necessary, however, to call attention to the fact that the peridotites repre- sent the most basic of known terrestrial rocks, while the mete- oric analyses which I have given represent the most acid type that have come to us from space. It is evident, therefore, that * The composition as shown by these analyses does not, so far as sodium is concerned, seem to harmonize with spectroscopic analyses, or Arrhenius’ statement*%o the effect that the nucleus of comets, like the meteorites fall- ing upon our earth, consists essentially of silicates, and particularly of the silicates of sodium. See Worlds in Their Making, pp. 104-105. For the benefit of those not familiar with the subject, it may be well to state that the principal mineral constituents of meteorites, aside from the metallic por- tions, are the silicates. of magnesia and iron, olivine and enstatite, with less commonly monoclinic pyroxenes and basic feldspars. Silicates of sodium must be rare, as shown by a simple glance at the analyses given. +The nnmbeér was limited, since nearly all reported analyses were of altered and highly hydrated exampies, while for purposes of comparison materials as nearly anhydrous as possible were needed. 474. G. P. Merrill—Composition of Stony Meteorites. V VI Sin Ahi peeks eye 43°59 Ale Ga Seki: heute neees 3:9) 5:30 HeOsy.w coh cma eae 19°29 840 Hes O nisin ke Mate cre 2°03 CaO wiser Co oe 2°06 4°11 MgO Se ae ay cay SRE Ee ee SS es 26°86 35°62 INO Pee ee oe ele 0°60 Keo ae a 0°38 0°36 MnO boiler 2) Wed he Wd We, 0°65 ae Cr Oe Ones ae 0:98 PERE. 100:00 100°01 as world-making materials they are insufficient, and if we are to regard our earth as an aggregate of cosmic matter, we must assume that the materials were of a much more highly sili- ceous type than any that have been reaching us from space within historical periods. This is presumably ‘the proper inter- pretation to be placed upon the results here shown. It is impossible through any process of magmatic differentia- tion to derive from such materials, in even approximate propor- tions, a series of rocks as widely variant and, in extremes, as highly siliceous, aluminous and alkaline, as are the igneous rocks of the earth. In fact, it would seem that they (the meteorites) themselves must ‘represent an extreme phase of magmatic differentiation from a more acid magma. Whether we consider the meteorites that have reached us within this period as but the fragmental remains of comets, or whatever their origin, it is certainly not going beyond ‘the realm of legitimate “hypothesis to assume that the relative pro- portions of the elements which go to make up the mineral matter in these various bodies in remote space, may vary widely; that the earth to-day, in its course, is but passing through* and receiving from space a deposit of materials representing one and the same original body, and that body one of an exceedingly basic nature, not necessarily resembling, in percentage composition, the materials which may have reached us during past and earlier stages of earth history.. *<««Meteoriten und Planetoiden sind daher die voribergehenden Zeugen einer voriibergegangenen Episode in der Geschichte unseres Planetensystems.”’ Ed. Suess, Ueber Einzelheiten in der Beschaffenheit einiger Himmelskor- er, Sitz. kais. Akad. der Wiss., vol. exvi, 1907. K. J. Bush—WNotes on the Family Pyramidellide. 45 Arr. XLIII.— Notes on the Family Pyramidellide ; by K. J. | Busy, Pu.D. [Brief Contributions to Zoology from the Museum of Yale Univ.—Ixix. | Tuere has recently been published by the Boston Society of Natural History an article on the very interesting family of Pyramidellide, written by Mr. Paul Bartsch,* Assistant Curator in the Department of Mollusks of the U. S. National Museum at Washington City, D. C. In his introduetion the author carefully reviews all of the literature relating to this family from the northeast coast of America, naming the species in each work, from Thomas Say, m. £821, to Geor sew Tryon, in 1886: le states that his paper is largely based on the U. 8. National Museum collec- tions; that he had also for study the collection from the Philadelphia Academy of Sciences and the large private collec- tion of Rev. H. W. Winkley, ete. ete. Quoting, as regards the synonymy: “In the present paper we have confined our- selves to the specimens at hand and to citations of literature necessary to a complete understanding of the nomenclature.” A further review of the work on this family, undertaken since 1886, and overlooked by Mr. Bartsch, may prove of interest to those studying this group. The Pyramidellideet belonging to the fauna of the east Atlantic have never been studied as a whole, but several stn- dents of Malacology had described a compar atively few species, those of special interest in this connection being from different localities along the coast of New England, West Indies, and Florida; in many instances without figures and, most unfortu nately, if figures were attempted, they are at the present time considered too poor for accuracy in determining the species. About 1896 the entire, very large collection “of the Pyrami- dellidze made by the U.S. Fish Commission during the years from 1872 to 1887, from the Bay of Fundy and the Banks of Newfoundland, south to Cape Hatteras, N. C., as well as many collections made by others at Labrador, Florida, and the Bermudas, in the Museum at Yale University were given into my charge to prepare for publication. In this connection acard catalogue of between 250 and 300 specific names referred to about 75 genera or subgenera was made. * Pyramidellide of New England and the adjacent region. Proceedings Boston Society of Natural History, vol. xxxiv, pp. 67-1138, plates 11-14, 1909. + This group as given by Tryon (Manual of Concholog gy, vol. viii, parts 32 and 33, pp. 294 to. 413, pls. 72 to 79, 1886) is a compilation of all known species with their descriptions and ‘fieures ; anew name is proposed where a former one proves preoccupied. 476 K. J. Bush-—Notes on the Family Pyramidellide. There were in existence at that time three or rather four small collections of species belonging to the genera Z'wrbonilla and Odostomia of special interest; one at the Museum at Ainherst College; one at the State Museum at Albany, New York; one at the Academy of Sciences of Philadelphia; and the fourth in the National Museum at Washington. The first contained the types of C. B. Adams ;* the second the speci- mens used in W. G. Binney’s Gould s+ the third those who by G. W. Tryon in his Manual of Conchology ; and the last the species described by Dr. Dall} from Florida. On visiting Amherst College I ‘found that the C. B. Adams’ vee had been misplaced, land for the time lost track of, (I understand they were subsequently studied at the N ational Museum). Professor John W. Clarke, then in charge of the Albany Museum, failed to find the specimens belonging to this group in the Gould collection. On request, those at Phila- delphia were loaned me for study and proved of so great interest that [ published a short report on them with one plate in the Proceedings of the Philadelphia Academy, in 1899.§ Coty pes and other specimens were also sent me by Dr. Dall. After several months of arduous work I had the collection ready for the descriptions of the numerous new species, fine figures of which had been prepared and arranged in plates. This work was then laid aside for other of more importance on different groups of mollusks; and most unfortunately has never been completed and published; although an attempt was being made to do so in the near future. In 1900, jointly with Professor Verrill,| I published a report on ‘the mollusks from the Bermudas, in which we described some new species of Zurbonilla and Odostomia and in several instances reéstablished some of the genera or sub- genera described by A. Adams, restricting them to definite types for the first time.4 * Descriptions of Supposed New Species of Watine Shells which Inhabit Jamaica. Contributions to Conchology, No. 5, pp. 72-75, 1850. + Report on the Invertebrata of Massachusetts, pp. 324-538, text figures, Boston, 1870. t+ On a Collection of Shells sent from Florida by Mr. Henry Hemphill. Proceedings U.S. National Museum, vol. vi, p. 382, Washington, D. C., 1888. § Descriptions of new species of Turbonilla of the western Atlantic Fauna, with notes on those previously known. Proceedings Academy Natural Sei- ences of Philadelphia, pp. 145-177, pl. viii, 1899. || Additions to the Marine Mollusca of the Bermudas. Transactions of the Connecticut Academy of Sciences, vol. x, pp. 028-030, pls. lxiv-lxv. New Haven, Conn., 1900. *| Pyrgostelis Monterosato, 1884 ; type—P. rufa (Philippi). V. & B., 1900+ D. & B., 1904. Mumiola A. Adams, 1864; type—WM. spirata A. Adams, 1860. V. & B., 1900+ D. & B., 1904 (not Mumiola Monterosato, 1884= Odos- tomiella B. D. & D., 1883). Mormula A. Adams, 1864; type—M. rissoina A. Adams. V. & B., 1900+D. & B., 1904. Cyclodostomia Sacco, 1892 ; K. J: Bush— Notes on the Family Pyramidellide. ATT In 1902, I visited the National Museum and found that Dr. Dall had given the species from the west coast of America, belonging to this group, to his assistant, Mr. Bartsch, to work up, as I had those of the east coast. In this connection rare species and types, both fossil and recent, were loaned by foreign museutins,* (especially the Berlin Museum, in which were the collections of H. and A. Adams, Petel, Dunker, and Hilgendorf ; and the British Museum, where are the collection of D’Orbigny and many others having species: belonging to this group; as well as the Museum at Copenhagen.) Figures were being made so that in the future there could, or rather would, be but small chance for errors in the identification of species. In 19038, an extensive report on fossils of California was published by Mr. Arnold, in the California Academy of Sci- ences. In this, Dr. Dall and Mr. Bartsch furnished the part on mollusks, and the senior author credited the work on the family Pyramidellide to Mr. Bartsch. Also, in 1904, a “Synopsis of the Genera, Subgenera, and Sections of the Family Pyramidellidee” was published by these authors in the Bulletin of the Biological Society of Washing- ton.t Quoting from the introductory remarks, ‘‘ The synonymy, which is very involved, is reserved for another paper in which the species of the west coast of America will be monographi- cally treated. It was thought best to put on record the classi- fication adopted, so that before the paper referred to appears the authors may have the benefit of criticism from other students.” Since the publication of my article in 1899, collectors of mollusks from California, Florida, and various places along the coast of New England have sent or brought their specimens to me for the identification of the species. This has been a source of great pleasure, as well as profit, as it enabled me, not only to become acquainted with rare species, as there was often but one specimen of a kind, but in instances where there were several, duplicates were given me, which were placed in our museum collection. When new forms appeared from the west coast they were referred to Mr. Bartsch; and those from type—C. mutinensis Sacco. V. & B., 1900+D. & B., 1904. Hvalea A. Adams, 1860; type—E£. elegans A. Adams. V.& B., 1900+D. & B., 1904. Cingulina A. Adams, 1850; type—C. circinata A. Adams. V. & B., 1900+ D. & B., 1904. Miralda A. Adams, 1864; type—WM. diadema A. Adams. V. & B., 1900+ D. & B., 1904. In three instances (Mumiola, Mermuila, and Cingulina), although citing the same type, these authors differ in the inter- pretation of the generic relations of these subgenera. * Dall, in Dall and Bartsch. Notes on Japanese, Indopacific, and Ameri- can Pyramidellide. Proceedings U. S. National Museum, vol. xxx, pp. 221- 269, pls. xvii-xxvi. Washington, 1906. + Vol. xvii, pp. 1-16. 478 A. SJ. Bush—Notes on the Family Pyramidellide. Florida to Dr. Dall; those from the New England localities were given an initial letter, as it was not considered advisable to give out manuscript names. In one instance, as a report on a collection from Coldspring Harbor, L. I., by Mr. Balch* of Boston, these initial letters were published and full credit given me. Among the most frequent visitors at the Museum was Rey. Henry W. Winkley, then of Branford, Connecticut, who is a most enthusiastic student and collector of New England mol- lusks; principally at Prince Edward Island, N. 8., Casco Bay, Woods Holl, Mass. and Branford, Conn. His coliection is unique in having numerous perfect specimens of the vari- ous species, and was of inestimable value in enabling me to decide many difticult questions of the correct identification in this puzzling group. To Mr. Winkley I also refused to give my new unpublished names, but used the same initial letters as for Mr. Balch. There were in his collection representatives of many of the new forms found in that of the U.S. F. C. as well as a few unique ones, not among the U.S. F. CO. specimens. 7 These specimens from Mr. Winkley’s collection are cited by Mr. Bartsch (p. 475), but no mention whatever is made of the fact that any student had seen the specimens or determined them. Among the thirty-eight (88) species cited and described in his report, and in most cases figured, there are seven (7) which he has never seen (/. wentricosa V. (not Forbes), 7. polita V., T. equalis (Say) V., O. brunert V., O. morseana B. tor O. sulcata V. (not A. Adams). O. dealbata (St.) Binney- Gould, O. eburnea (Stimpson) V.); six (6) from Winkley’s collection, as types, with two (2) (P. producta (C. B. Adams) and 7. mighelsi B. for TZ. costulata V. (not Risso). Fifteen (15) are represented in the Winkley collection, as well as in that of the U. 8. F. C. in the National Museum ; and eight (8) are from the U.S. F. C. collection alone. Of these, three (3), Z. cascoensis, T. verriulli, and O. bushiana are described as new. The new subspecies or varieties, 7. abysszcola, T. bran- Fordensis, T. senilis, O. bedequensis, and O. ovilensis, are not included in this enumeration. The two specimens identitied as Hulimella ventricosa V er- rill, 1880 (not Forbes, 1843), have proved to be two distinct species. The worn one from Eastport, Me., is now considered identical with Hulimella polita, Verrill, 1872, and the one from Station 873 is an Aclis tenuis Verrill, 1882. Therefore the name .Pyramidella (Hulimella) ventricosa Bartsch (p. 70) is superfluous. pppoe ass Boston Society of Natural History, vol. xxix, pp. 145-146, 899, : K. J. Bush—WNotes on the Family Pyramidellide. 479 The referring in 1884, of the three species chariessa, nitida, and ducida tothe genus Hulimella, instead of Hulima, was probably an accidental error overlooked in reading the proof. This correction, noted on p. 71, has long stood on our distribu- tion sheets, but never having been published was a MS. name. As duceida isatrue Hulima, the name does not now conflict with Hulimella (Syrnola) lucida A. Adams, 1870; but the name nztzda Verrill, 1884, is preoccupied by Aelania nitida Philippi, 1844—. intermedia Cantraine, 1835, and by Hulima nitidu A. Adams, 1866=F. netidula A. Adams, 1861; also by Letostraca nitida A. Adams, 1861=Hulima Tryon, 1886, and will therefore take the new name, Hulima verrilliana.* There seems to be no reason for dropping the final z used in the original spelling of smethz Verrill (p. 71), nor for placing the species in the subgenus Syrnola, rather than in the sub- genus Hulimella, used “by Verril in 1889. The use of Zu?- bonilla for Syr nola tr yoni is a typographical error for Hudli- mella. The referring of fusca C. B. Adams from New Bedford, Mass. (p. 73) to Pyramidella (Syrnola?) seems unnecessary. The species, although brown in color, has the form of a typical Odostomia, and should be reéstablished in that genus, as given by Gould, 1840. Adams’ figure is poor and is like our disw- turalis without sculpture. Gould’s two figures 1840 and 1870 are larger with more Hee whorls and more gradually tapered | spire. There is great variation in the relative stoutness among the many specimens of Zurbonilla bushiana Verrill (p. 79), as well as in the relative strength of the axial ribs; those having well-developed ribs received the subspecitic name, abyssi- cola suggested as a variety by Verril] and Bush in MS. There are comparatively few specimens which differ from both the typical and subspecitic forms, going to the opposite extreme, in being entirely destitute of definite axial ribs, the surface smooth and shining, often iridescent ; for these w e pro- pose the new subspecific or varietal name znornata. All the specimens which I have studied are destitute of spiral. lines, _* Eulima distorta Verrill, 1881—Eulima perversa, new name. It is similar to EF. arcuata C. B. Adams, 1850=new name?, not E. arcuata Sowerby, 1866=E. major Sowerby, 1834; Dall, 1889; not Odostomia arcuata A. Adams, 1860. Like E. distorta G. O. Sars, pl. 11, fig. 23, 1878, not E. distorta Deshayes (Compared with typical specimens from. Monterosato). not Melania distorta Philippi, 1886=£. incurva Renieri, 1804; not Melania distorta Defrance, 1824=—new name ?, not Leiostraca distorta Pease, 1860=Hulima, new name ? Eulima intermedia Verrill, 1881=Eulima Sarsi, new name ; not E. inter- media Cantraine, 1835 ; not Dunkeria intermedia Carpenter, 1857=Odosto- mia (Dunkeria) ; not Odostomiu intermedia Brusina, 1869=Odostomia can- aliculata Philippi, 1844. 480 K. J. Bush—WNotes on the Lamily Pyramidellide. as the exceedingly fine microscopic strie, always discernible under high power objectives, are not taken into consideration. Therefore its relation to the subgenus Strzoturbonilla (p. 79) seems imaginary. This subgenus is described by Sacco, “Testa sicut in Zurbonilla (stricta sensu) sed transversin striole par- villimee (sub lente vix visibiles),” ete., etc., and his figure of S. apicina shows many very fine, distinct, incised spirais between the ribs and on the base, similar to the seulpturing found in the true 7. interrupta (p. 481). _ The Zurbonilla polita Verrill, 1882 (p. 75) does not con- flict with Odostemia polita Bivona, 1832; nor Pease, 1867. For discussion of the genus Zwurbonilla (p. 76) and type see p. 483. The name nzvea is extensively used in this group, but Zurbonilla nivea (Stimpson, 1851 and 1853) from 40 fms. off Grand Menan, N. B., has priority. The shallow water species described and figured as nzvea by Bartsch (p. 77) 1s not like the typical specimen from U. 8. F.C. Station 871, off New- port, R. [. in 115 fms., 1880, described by Verrill* in 1881, (the - specimen cited from Station 949 is the true navea). The axial ribs end just above the Geep suture; the intercostal spaces showing a basal curve, thus leaving a very narrow, smooth, sutural area. The whorls are less rounded than indicated in the figure, p. 484, f. 1. The nea Bartsch is a typieal T. stricta Verrill. Ina lot of over 20 specimens, from Vine- yard Sound, there is great variation in the number and width of the axial ribs. The largest specimen, having 10 post- nuclear whorls, is hke Bartsch’s figure 9, Plate IL, but is not the 7’. stricta Bartsch, figure 6, which is a typical 7. equalis Say (p. 78). [See p. 484, f. 5, from Woods Holl, Mass., 1882. ] The Zriptychus niveus Morch, 1875 (type and only species ~ of the genus) is described as having a few spiral lire; the liree extending into the aperture forming three plications on the columella. Aperture subemarginate anteriorly, somewhat excavated below the lire. Nucleus reversed. The nucleus is the only character showing any relation to the Pyramidellide. The aperture would exclude it, as it shows nearer affinity to the genus Cerithiopsis. Dr. Dall, 1889 (also Dall and Guppy, 1896), suggested its being synonymous with Oscilla, which seems hardly possible ; indiscreta Guppy, 1896, is described and figured as Triptychus (Oscilla). The Pyramidellida vincta Dall is placed as a synonym of TZ. niveus Morch by Tryon, 1886. Although stating that “‘ The shell is scarcely a Pyramidella—the sculpture and plications are different,” Tryon uses 7riptychus as a section of the Pyra- midellide, and Dall and Bartsch, 1904, p. 5. as a subgenus. The Dunkeria falcifera Watson, 1885, from Bermuda may prove to have affinity to this group. * Proceedings U. S. National Museum, vol. iii, 1881, p. 379. K. J. Bush—Notes on the Family Pyramidellide. 481 The genus Peristichia Dall, 1889 (type P. toreva Dall, 1889), used as a subgenus of Turbonilia, 1904, p. 9, seems to have more affinity to Rissoina than to any genus among the Pyra- midellide. The name Zwrbonilla areolata Verrill is not preoceupied by Turriteila areolata St., 1851, nor Chemnitzia areotata Ray- neval, 18—. which is equal to Turbonilla indistincta Montagu (teste Jeffreys, 1884). This rare species, p. 484, f. 4 (type from New Haven, Conn.), described by Verrill, 1874, has flattened whorls, giving it an obelisk-like form. The axial ribs are nar- row. with wide, shallow, intercostal spaces, crossed by five dis- tinct, incised lines or series of pits. In some specimens the axial ribs appear only as interruptions of the spiral sculpture. The areolata of Bartsch (p. 86, pl. 12, figs. 19, 24) is another spe- cies similar to Zurbonilla (Pyrgiscus) vinee Bartsch (p. 83). TURBONILLA INTERRUPTA (Totten) Bush, 1899, pp. 148-151. ' Turritella interrupta Totten, 1835, p. 352, fig. 7. Type locality, —Newport arbor, kh. F. Not Chemnitzia interrupta A. Adams, 1853. Not Turbonilla interrupta C. B. Adams in Amherst collection. Not Turbonilla (Pyrgiscus) interrupta Bartsch, 1909. Not Eulima interrupta Sowerby, 1834, = Niso Sowerby, 1854. Not Eulima interrupta A. Adams, 1884, =Eulima secunda, new name. An historical sketch of this species was given by me in 1899. Figure 9, produced here for the first time, isfrom an U. 8. F.C. specimen dredged in 1880, at station 770, Narragansett Bay, in 8 fathoms. The specimen measures about 5™™ in height and about 1-5" in breadth. Figure 10 is a piece of the shell greatly enlarged to show the character of the micro- scopic sculpture, especially the incised or impressed spiral lines. These incised lines, varying in width, produce an alternating series of apparently raised ones, often arranged indistinctly in pairs, and agree well with the description given by Totten. The specimen described (p. 87) and figured by Bartsch, unfortunately does not agree with this, therefore I would dis- tinguish it as Zurbonilla pseudoinierrupta, new name. The shelis, as a rule, are of a lustrous white color, semitrans- parent when fresh, often with one, sometimes two, delicate median, or sutural and median bands of rufous; in some of the most mature specimens this color entirely covers the whorls, especially the upper ones. Turbonilla (Pyrgiscus) buteonis Bartsch (p. 89) is the same as sp. f’inour U.S. F. C. collection. Turbonilla (Pyrgiscus) sumnert Bartsch (p. 92), type and only specimen, is probably the young of a more common spe- cies. The young often appear disproportionately stouter than the adult forms. 482 A. SJ. Bush—Notes on the Family Pyramidellide. Odostomia (Chryssalida) bushiana Bartsch (p. 99) is like specimens in our U.S. F. C. collection from shallow water off Cape Hatteras, N. C. There is also a small lot from Vine- yard Sound, Mass. (Not Odostomia bushiana Jettreys, 1884.) The Odostomia (Lolwa) henderson Bartsch (p. 101) is iden- : tical with specimens trom Woods Holl, Mass., in our own col. lection, identified as an immature Acie Rene Verrill, 1880. Its generic affinity needs further study, as it is very doubtful whether it can be related to the Pyramidellide. As Jolwa (p. LO1) is deseribed as having spiral cords and axial riblets, this species is erroneously referred to this subgenus, for it has but a few very fine spiral incised lines. Odostomia (Menestho) brunert Verrill, 1882 (p. 102). ie and only specimen is lost. Odostomia (Menestho) sulcata Verrill, 1880 and 1882 (p. 484, f. 2, from Georges Bank, in 45 fms.), is O. sulcosa Mighels, 1843 (Phasianella Mighels and Péssoella Stimpson ; Binney-Gould, 1870). The name morseana Bartsch (p. 104) is, therefore, not needed. There is so great variation found among a large series of specimens of Odostomia bisuturalis Say and O. trifida Totten (pp. 104-108) that it seems desirable to unite the two forms under dzsuturalis, with subspecies trzfida ; the exigua Couth- ouy, 1838 (p. 106) also being a possible subspecies. The sub- species ovilensis Bartsch (p. 107) is simply a very large form. The subspecies bedequensis Bartsch (p. 106) is much more nearly related to O. empressa Say (p. 103). In fourth line of the description, axial is undoubtedly intended for “spiral.” In a marginal note p. 328 in Binney-Gould, 1870, Prof. Verrill has written : ‘‘ Have seen shell figured (597). It is a genuine O. trifida.” Below, under O. trifida, he adds “ Pasithea sor- dida Lea (this Journal, vol. xlii, p. 110, pl. i, fe6) toute synonymy. Odostomia (Odostomia) modesta Bartsch (p. 108, pl. 13, fig. 50) is distinct from the O. modesta Verrill, from Eastport, Me. (p. 484, f. 8), which has flattened whorls and a somewhat angular body whorl, and much more prominent nucleus. Therefore it requires the new name Odostomia gibbosa, not preoceupied by the Chemnitzia gibbosa Carpenter, 1857, which is a Turbonilla. The Odostomia (Liostomia) eburnea (fissoa and fissoella Stimpson), 1851 (p. 109) is not the same as that in binney- Gould, 1870, p. 297. Specimen, p. 484, f. 7, is from Mt. Desert, Me., collected by W. E. Cleaveland, 1862. Odostomia (Odostomia) dealbata (Stimpson) (p. 108) is not the same as fig. 595 given in Binney-Gould, p. 327. This, as indicated ina marginal note, represents a “ much larger and dif- ferent species”? which: may be called O. Gouldi, new name. F. 6 is a typical form from Vineyard Sound, Mass., 1875. K. J. Bush— Notes on the Family Pyramidellide. 483 Odostomia producta (C. B. Adams) Gould, 1840 (p. 72) from Wood’s Holl, Mass., is shown on p. 484, f. 11. _ TLurbonilla elegantula V errill (p. 84). The type is from Vine- yard Sound, Mass., 1875 (f. 12, p. 484). vf urbonilla costulata Verrill, 1874. The type from New Haven, Conn. (p. 484, f. 3), is not the Zurbonilla (Pyrgiscus) mighelsi (Bartsch), p. 88. Itisa very stout form of Zurbonilla interrupta (Totten) and may be designated as variety obesa, new name. At the time of defining the genus Zurbonilla Risso, 1826, (1899, p. 147), I had failed to notice that the genus had been proposed for three fossil species, as stated by “Jeffreys in his British Conchology, vol. iv, p. 108. “In 1862 [for 1826] Risso (Hist. Nat. “PEm. Mer., lv, p. 224) formed the genus Turbonilla, on the MS. authority of Leach, for three ‘fossil species ;” etc., etc. Although I may have erred i in naming the recent species, T. lactea(Linné) = 7. elegantissima (Montagu) for the type species, I did not in any way interfere with the correct interpretation of the genus. I also divided and subdivided it (pp. 172-174), according as the species had not, or had, spiral sculpture; the second division according to the character of these markings. Clearly detined these and designated them by initial letters, as I did not feel competent to make use of the names which had been pro- posed by Adams and others. In no case had Adams desig- nated a type species, as such, and in many instances he had grouped several dissimilar forms. The difficulty of correctly interpretating these was greatly increased by the lack of good figures. Lists of the species, which had been discussed in the foregoing pages, were given under each division, so that it was hardly possible for any one to misunderstand my meaning. In 1900, Professor Verrill and I did adopt some of Adams’ names, restricting them to definite types for the first time, as well as the names proposed by Monterosato, Sacco, and others (p. +76). As no complete synonymy was given by Messrs. Dall and Bartsch in 1903 and 1904, these facts were not mentioned, but why Mr. Bartsch in 1909 should fail to note them, as they seriously affect the correct authorities tor the combination of names, does not appear. There seems to be no reason for the new name 7. typica Dall and Bartsch, 1903 and 1904 (Bartsch, 1909, p. 76) for 7° plicatula Risso not Seacchi, for not only should my type of 1899 stand, having priority and also being the first one desig- nated for the genus, but some authors, followed by Tryon, 1886, make plicatula Risso, elegantissuma Montagu, and lactea Linne synonymous. Sacco, 1892 (p. 654) gives dactea as his first species under Z’urbonilla, with sixteen (16) named varieties; Chemnitzeva elegantissima (Montagu) as a synonym of the first, var. Campanelle. Zoological Department, Yale University Museum, May, 1909. 484. A. J. Bush—Notes on the Family Pyramidellida. Fig. 1.—Turbonilla nivea (St.) V., x 10, p. 480. Fig. 2.—Odostomia sulcosa (M.), x 10, p. 482. Fig. 3.—Turbonilla interrupta (T.) var. obesa n. n., x 10, p. 483. Fig. 4.—Turbonilla areolata V., x 10, p. 481. ae Fig. 5.—Turbonilla equalis (Say) V., x 8, p. 480. . Fig. 6.—Odostomia dealbata (St.) Gld., x 9, p. 483. Fig. 7.—Odostomia eburnea (St.) Gld., x 18, p. 483. Fig. 8.—Odostomia modesta St., x 9, p. 482. Fig. 9.—Turbonilla interrupta (T.) Bush, x 12, p. 481. Fig. 10.—The same. Sculpture, much enlarged. Fig. 11.—Odostomia producta (C. B. Ad.) Gld., x 9, p. 483. Fig. 12.—Turbonilla elegantula V., x 138, p. 488. Chemistry and Physics. 485 So PEN PEE hey iIN Pe PL EG EN Che I. CuHemistry AND Puysics. 1. Liquid and Solid Radium Emanation.—GRay and Ramsay — have made some interesting observations upon the remarkable gas which is spontaneously evolved from radium. Having col- lected some of the emanation in a state of fair purity, they com- pressed it in a capillary tube with the very fine bore of 0:08™™ diameter. When sufficiently small, there was seen at the conical point of the tube a minute column of liquid, easily visible under low microscopic power. By altering the volume more or less liquid could be condensed, and by transmitted light all the phe- nomena of condensing and evaporating a liquid could be observed. By transmitted light the liquid appeared colorless like water, but when the illumination from behind was extinguished the liquid was visible by its own illumination as a greenish or bluish green phosphorescent layer, not very luminous, but more so than the gaseous layer. Its vapor pressure was measured at several tem- peratures, but as the gas was not quite pure, an allowance had to be made for this, so that the results given in the following table are only approximate : Pressure. Temperature. OOr a 72S 10 200 —66'1 500 —53°6 760 —48°5 1000 — 43°] 2000 —31°0 5000 —12°8 10000 + 1°5 a The density of the liquid was estimated with rough approxima- tion as about 7, assuming the gaseous emanation to be 100 times as dense as hydrogen, and the conclusion was reached that it is considerably more dense than xenon, namely 3:52. While the liquid was only feebly phosphorescent, when it was cooled by touching the tube with liquid air it became brilliant, the color changed to light steel-blue and blazed with light. Continued application of the liquid air caused the color to change, first to white, then to yellow, and finally to orange. ‘Through the micro- scope it looked like a brilliant little arc light. On removing the liquid air the reverse changes in color took place, and these changes could be repeated again and again. ‘There was no doubt that the brilliantly luminous substance was a solid.— Chem. News, xcix, 165. Hey Det ws 2. The Gases Evolved by the Action of Cupric Chloride upon Steels.—The usual method of determining carbon in steels consists Am. Jour. Sct.—FourtH Series, VoL. XX VII, No. 162.—Junez, 1909. Bi) 486 Scientific I ntelligen Ce. in treating the metal with a strong, nearly neutral solution of potassium and cupric chlorides in order to dissolve the iron, and then making a combustion of the filtered residue. It has been known for some time that this operation involves the loss of small quantities of carbon, and recently Gourat has carefully studied the matter. He has found that when steels are attacked by very slightly acid solutions of potassium and cupric chloride at a moderate temperature and in a current of nitrogen gas, there is a loss of gaseous compounds of carbon amounting to from 0:01 to 0°05 per cent. He states that this loss may be diminished nearly one-half by making the combustion of the carbonaceous residue directly after draining it with the filter pump, and with- out drying it in the oven, for under these circumstances the carbon dioxide formed remains entirely condensed in the residual carbon. He states further that the loss of carbon may be per- haps entirely avoided by boiling the copper solution resulting from the operation, passing the gas which comes off with an excess of oxygen through a glass tube provided with a red-hot platinum wire, and collecting the resulting carbon dioxide in baryta water.— Comptes Rendus, cxlviii, 988. Hi Li Wa 3. The Radiation of Potassium Salts.—That potassium salts show a faint amount of radio-activity was first observed by Campbell and Wood, and the fact has been confirmed by others. E. Henrior has now made a further study of this phenomenon, and finds that while others have announced that the rays from potassium are very heterogeneous, his own observations lead him to the conclusion that they are practically homogeneous. He studied the absorption of the radiation by tin-foil of varying thickness, and since the radiation-activity of potassium is of the order of ;gig7 of that of uranium, be used 1 ke. of salt spread over a surface of 1300°™’. From the results of his experiments he concludes that potassium emits B-rays only, that there is little probability that the radiation is due to an already known radio- active element, and that the activity is probably caused either by potassium itself, or by an unknown body which is always associated with it.— Comptes Rendus, exlviu, 910. Hi. LW 4. A Course of Qualitative Chemical Analysis of Inorganic Substances ; by Otin FREEMAN TOWER. 8vo, pp. 83. Philadel- phia 1909. (P. Blakiston’s Son & Co.)—The large number of text-books on Qualitative Analysis which have appeared, and are constantly appearing, is due to the fact that nearly every teacher of the subject desires to present it to the student in a manner somewhat different from that used by anyone else, either in regard to the course of analysis followed, or in connection with the theoretical and explanatory details. The book under consideration gives a well-chosen course of analysis, with abundant and excellent explanatory notes, and in these respects the book appears to be an unusually good one. The author has attempted to lead up to the facts by basing them upon the theory of ions—a method of teaching which has Chemistry and Physics. 487 become somewhat popular. Whether this course is the best one or not is a matter of opinion, but it appears to the reviewer that _ qualitative analysis should be presented in the attitude that it teaches certain facts, for instance, the fact that acids, bases and salts readily exchange their radicals in solution, thus leading to the precipitation of insoluble compounds, and the removal of volatile compounds by evaporation. When these facts have been grasped it may be desirable to call attention to the ionic theory as a method of explaining these facts; but to base facts upon a theory is not the logical way, for the theory is actually derived from such facts. EDC Dy Wi 5. A Suggested Method of Ascertaining the Existence of Chlo- rophyll on Planets.—N. Umow suggests the application of the following method: Paper discs covered with chlorophyll reflect the light of a Nernst lamp into an optical apparatus consisting of an objective, a cylindrical lens, a Savart polariscope with a tour- maline plate; a direct vision spectroscope and finally a small power telescope in a reversed position. The Savart striz run horizontally through the spectrum and are modified in a striking way by the presence of the chlorophyll. The author gives a figure of the appearance: which is presented ; and since he has not the proper facilities recommends the method to astronomers. —Physik. Zeitschrift, April 15, 1909, pp. 259-260. Jel 6. Condensation of the Radium HEmanation.—RuTHERFORD and Soppy showed in 1903 that the radium emanation condensed from the gases with which it was mixed at a temperature of about —150° C. Rutherford has now worked with larger quan- tities of radium. He finds that the density of the liquid emana- tion is not less than 5, and its atomic weight 222. The absence of combining properties indicate that it is an inert gas, the heaviest known having a density of 111 times that of hydrogen. {C£. No. 1 on p. 485.) — Phil. Mag., May, 1909, pp. 723-729. 35.7. 7. Electric Origin of Molecular Attraction.— W 1LLIAM SUTHER- LAND has previously brought forward evidence in support of the view that molecular attraction varies as the fourth power. He considers, in connection with this view, the attraction between two small magnets, directed along a straight line which also varies as the fourth power; and is led to consider a bipolar elec- tric attraction of molecules, with reference to cohesion. He alludes to papers by Fessenden and Reinganum, on the electrical origin of cohesion which might arise from a bipolar condition of molecules. Sutherland points out that there is no theoretical or experimental justification of the literal truth of Fessenden’s assumption for gases. Nevertheless, J. EH. Mills has discovered a remarkable relation which seems to justify the assumption com- pletely. Mills’ application of his law to gravitation was errone- ous, but the law can be applied to electric attraction, and is expressed as follows : The total potential energy of a number of like molecules is the same as if each caused its own domain to be uniformly electrized with an electric moment proportional to the 488 Scientific Intelligence. linear dimension of the domain, the direction of electrization being such that in general any molecule attracts its six immediate neighbors. It is proposed to look upon atoms as electrized, just as we speak of a magnet as being magnetized. In regard to total energy, each molecule behaves as if it had an electric moment proportional to the linear dimensions of its domain, whereas in the matter of mutual energy each molecule has an electric moment of amount E'S (E charge, S distance between poles) which is investigated in connection with the laws of molec- ular attraction.— Phil. Mag., May, 1909, pp. 657-670. sie 8. Physical Measurements ; by A. Witmer Durr and ArTuur W. Ewer. Pp. 211. New Haven, 1908 (Dorman Lithographing Co.).—This is an excellent laboratory manual containing ninety- one experiments of considerable range of difficulty. The intro- ductory discussions and the descriptions of experiments are marked by a very commendable brevity and by a generality of treatment which gives the essential principles of the matter with- out going into the details of apparatus which vary from one laboratory to another. References are given to standard text- books in which details can be looked up if necessary. The experi- ments are well chosen, and the whole atmosphere of the book is that of sound and accurate work. A somewhat unusual feature is the inclusion of a section on physical chemistry, in which are grouped some experiments not often found in text-books on physics, together with others which are ordinarily found scattered among the various subdivisions of the subject (heat, electricity, light), but of which the chief interest is physico-chemical. The figures are simple line drawings of small size; they are usually clear, but some of the more complicated diagrams would be improved by being drawn to a larger scale. As a whole the book should prove very useful to laboratory teachers. 4. A. B, II. GroLtoGcy AND NaAturRAL HIsTory. 1. Monograph on the Higher Crustacea of the Carboniferous Rocks of Scotland ; by B. N. Peacu. Mem. Geol. Surv. Great Britain, Pal., 1908, pp. 82, pls. 12.—In this quarto work are described in great detail 41 species and varieties of Schizopoda based on more than 2000 specimens from the Carboniferous rocks of Scotland, the accumulation since 1880. The excellent wash drawings are by Dr. Peach and are reproduced by the Collotype process. There are 34 named forms grouped under the genera Tealliocaris, new (with 6 species), Pseudogalathea (3), Anthra- palemon (1), Pygocephalus (1), Perimecturus, new (6), Palco- caris (2), Palaemysis, new (3), Anthracophausia, new (2), Crangopsis (10). All of these are grouped under existing fam- ilies as defined by Sars, of the Mysid and Euphausiid groups of Schizopoda, except Perimecturus. The individuals rarely attain a length of 14 inches, but a species of the last-named genus has a body length of 5 inches. €. 8. Geology and Natural History. 489 / 2. Fossils from the Silurian Formations of Tennessee, Indiana and Illinois ; by Aue. F. Forrstz. Bull. Denison Univ., April, 1909, pp. 61-107, pls. i-iv.—Here are described 74 forms of Silu- rian fossils, most of which are new. - Of these 40 derive their specific names from localities or men. Seven new subgeneric names are proposed not one of which is clearly established. Two of these are coral subgenera, Craterophyllum aud Plaiyaxum ; of brachiopods, Stegerhynchus, Cliftonia, Schizonema, and Platy- merella, and the bivalve Newsomella. CuSs 3. Illinois State Geological Survey. Bulletin No.9. Paving Brick and Paving Brick Clays of Illinois ; by C. W. Rorrs, fee Lunpy, A. N: Tareor and: I: O. Baker; Pp. xin, 3163 3 plates and 33 figures. Urbana, 1908 (University of Illinois).— This Bulletin is devoted to a detailed discussion of a subject of much general economic importance. The geology of clays with particular reference to their origin and their distribution in the State is described in the opening chapters by C. W. Rolfe. The chapters following, by R. C. Purdy and A. N. Talbot, present the facts in regard to the properties of high-grade paving brick, the tests used in determining them, and the qualities of the clay demanded. The final chapter by I. O. Baker is devoted to a dis- cussion of the proper construction and care of brick pavements. 4. Wisconsin Geological and Natural History Survey. EK. A. Birex, Director, W. O. Horcuxiss, Economic Geologist.— The Wisconsin Survey has recently issued six geological maps of the Lead and Zine district, together with a leaflet, serving as a Supplement to Bulletin XIV, by U.S. Grant (noticed in vol. xxi, p. 470 | 5. foe Locality of Diamonds in Africa.—The discovery of diamonds in German Southwest Africa in May, 1908, was announced some months since in the public press. An account is now given by H. Lorz of their method of occurrence, while KE. Katser adds a description of the crystalline form. It appears that the gems occur in a loose material consisting of from 70 to 80 per cent of reddish fine sand, and the remainder of fine gravel ; associated with the last named are small finely striated pebbles, chiefly of agate and jasper. ‘The principal locality is at Liideritzbucht, but extends also along the coast to Angras Juntas, half way to the mouth of the Orange River, a distance of 130 kilometers. The author expresses the view that the diamond deposits are old coast formations in part rearranged by the wind. They are probably connected with the general flood region of the Orange River, the stones offering many points of resemblance to those obtained on the banks of the Orange and Vaal rivers in the interior. The uniform size of the stones is a matter of interest; the majority range from 4 Oey ; carat, the largest stone weighing 2 carats, while stones of 4 carat are comparatively frequent. The quality i is unusually high. Lotz calculates, from the some- what insufficient data thus far available, that a production of 490 Secentific Intelligence. 180,000 carats a year may be hoped for.— Centralblatt fiir Miner- aloyie, etc., pp. 285, 251. 6. LInterferenzerscheinungen im polarisirten Licht. Photogra- phisch auf genommen; von Dr. Hans Hauswatprt, Dritte Reihe. Magdeburg, 1908.—The scope and value of this work, of which the third series of plates has recently been published, has been somewhat fully presented in the notice of the First Part (on p. 397 of volume xviii). This series consists of 72 plates which, in beauty of execution, are fully equal to those which have preceded. The phenomena illustrated are quite varied in character. Some of the subjects covered are as follows: Phenomena in converg- ing polarized hght with circular polarizer and analyzer ; various combinations of quartz plates in converging polarized light ; phenomena presented by highly absorptive media as andalusite, also magnesium-platinum and yttrium-platinum ge 7. Complete Mineral Catalog ; compiled by W. M. Foote. Twelfth edition. Pp. 320. Philadelphia, 1909 (Foote Mineral Company).—tThis twelfth edition of the Foote Mineral Catalogue appears in much enlarged form and is made attractive by its excellent topography and the introduction of numerous well- executed figures. It gives the names of all recognized mineral species, including those recently described, which will be included in the Second Appendix to Dana’s Mineralogy, now in press. The composition of each species is given, and also the more important physical characters. 8. Introduction to the Study of Rocks ; be L. FLEercuEr. Brit. Mus. Nat. Hist., Guide to Mus. Coll. Fourth edition. 8°, pp. 155, 1909.—This is a new edition of the guide book published in 1895. Although considerable of the original material has been retained, much new matter has been added to bring the work up to date. The same general grouping of the rocks is retained, but greatly expanded to include recently described kinds and so altered as to make the primary divisions on the mineralogical basis, the secondary ones those of texture. The numbers of the exhibition cases in the Museum are added on the margin, so that specimens illustrating the phenomena discussed may be readily found. Although the work is intended for a definite local pur- pose, at the same time petrographers will find much that is of general interest in it, especially with respect to the author’s views on classification. It is clearly and simply written, the subject matter well chosen, and it will without doubt be of great service in the field for which it was designed. ii Neues 9. Determination of Rock-forming Minerals ; by A. Jouann- sEN. New York, 1909 (Wiley and Sons).—In a previous notice of this work (this Journal, vol. xxv, p. 529, 1908), it was stated that a method of cutting the edges of the pages was indicated, by which an indexing was produced to facilitate the use of the tables. In practice this proved cumbersome and may have hin- dered the use of this very useful work. Since then the publishers have devised an extremely neat and efficient method of doing this Geology and Natural History. 491 themselves, and those who now obtain the book in this form will find it very convenient for use. st Wee 10. Trees, A Handbook of Forest Botany for the Woodlands and the Laboratory ; by the late H. Marsuatt Warp, Professor of Botany in the University of Cambridge (England). Vol. V. Form and Habit. Cambridge, 1909 (The University Press).— The volumes of this series are perfect of their kind. They are handy, well printed, well planned, and well up to the times. The present volume has been prepared from the notes left by the lamented and accomplished botanist, Dr. Ward, who had a remarkable facility in presenting difficult subjects in an attractive manner. Some of our readers will remember the charm which he threw around the mysterious activities in the laboratory of green leaves, imagining himself a guide conducting an inquiring person into the leaf itself. Dr. Percy Groom has managed his task with skill and success. He has not changed Dr. Ward’s text in any manner, but he has selected, from abundant material at hand, effective illustrations for every part of the subject. There is not a botanist who cannot derive instruction from this modest and rich treatise on Form. Furthermore the adaptations are clearly described in a thoroughly scientific manner but without the use of too many technical terms, so that it would be possible for any intelligent person, unfamiliar with botany, to gain from these pages a clear notion of the marvelous fitness of organisms to their surroundings. Unquestionably Dr. Ward would have expanded the chapter on Bark somewhat more, but Dr. Groom has done wisely in leaving it about as it was. It will not lead any one astray. ‘The convenient volume, although very small, is provided with an excellent index, rendering it even more useful to every reader. G. L. G. 11. Mendel’s Principles of Heredity ; by W. Batson, F.R.S., Professor of Biology in the University of Cambridge (England). Cambridge, 1909 (The University Press); New York (G. P. Putnam’s Sons).—Professor Bateson has rendered great service by his clear account here given of Gregor Mendel’s interesting and buried researches. Few incidents in the history of biological science are more surprising than the utter ignoring of important work by contemporaries who would have gladly acknowledged their merit if they had been properly brought to general notice. The comprehensive work by Sprengel in regard to the relations of flowers to insects fell stillborn from the press, and was abso- lutely neglected by all of his associates and soon was totally for- gotten, until after fifty years it came into prominence as an important factor in the literature of adaptation. Goethe’s treatise on Metamorphosis was likewise neglected and did not receive any recognition as a suggestive speculation until chance brought it to the notice of two botanists who saw that it contained a solid although small grain of truth. Mendel’s case is harder to explain, for his treatise appeared to be in proper form for due consideration by students in biology, but it was completely lost 492 Scientific Intelligence. to the scientific world until the merest chance brought it to light. In an extended notice which we hope to give in the next number of the Journal, we shall call attention to the attractive manner in which Professor Bateson has presented the Mendel essays and illustrated them by confirmatory critical studies. We cannot too strongly advise our readers to avail themselves of this convenient annotated reprint. Glas 12. Catalogue of the Lepidoptera Phalene in the British Museum. Vol. VII. Catalogue of the Noctuide; by Sir GrorGE F. Hampson. Pp. xv, 709, with 184 figures; also plates evili-cxxil. London, 1908.—The earlier volumes of this import- ant catalogue of Moths have heen repeatedly noticed in this Journal. The present volume is the seventh of the series and contains the first part of the large sub-family Acronyctine. It is characterized by the trifid neuration of the hind wing com- bined with spineless tibiz and smooth eyes not surrounded by bristle-like hairs. This sub-family comprises some 3000 species, belonging to over 300 genera, and two additional volumes will be required to embrace them all. The manuscript for these is stated to be ready for the press and it is expected that they will appear in 1909. The supplementary volume contains 15 plates each with from 22 to 32 beautifully executed figures. Ill. Miscetuanrous Screntiric INTELLIGENCE. 1. Bulletin of the Mount Weather Observatory: Prepared under the direction of Wituis L. Moore, Chief U.S. Weather Bureau. Vol. ii, Part I. Pp. 54, 6 charts. Washington, 1909.— The Mount Weather Observatory is making very important con- tributions to the investigation of the meteorological conditions of the upper atmosphere, as determined by kite flights and balloon ascensions. ‘These topics form the subject of an article in the present number by W. J. Humphreys. It may not be generally appreciated, although the facts have been presented from time to time, that the observations of the past ten years, carried on by balloons and by kites, equipped with suitable registering appara- tus, have brought out a large number of important facts in regard to the atmosphere. Three more or less distinct regions are recognized: 1. That of terrestrial disturbance extending up to an elevation of about 3,000 meters, in which the temperature- gradient is usually irregular and often shows reversion, This includes the principal region of clouds and precipitation. 2. A region of uniform changes, lying between that just mentioned and the 10,000 meter level in which the temperature-gradient is nearly constant and approaches the adiabatic. This region is comparatively free from condensation and precipitation, and while at times the seat of vertical convections its normal condi- tion is one of stability. 3. Above this is the region of perma- Miscellaneous Intelligence. 493 nent inversion, or all the explaered portion of the atmosphere above the 10,000 meter level. Here the temperature-gradient is small and usually positive, so that vertical convection is impossible. Various suggestions have been made to explain the inversion of temperature in this upper region, but no one of these is entirely satisfactory. Another chapter gives the results of observation of upper air temperatures at Mount Weather, Trapp and Audley by the Aerial Section in charge of W. R. Blair. The charts show the upper air isotherms for the period covered, in July, August and Sep- . tember. A chapter by W. R. Gregg describes the auroral dis- plays and magnetic disturbances of September, 1908, at Mount Weather. The observations show a period of maximum of auro- ras in 1908 corresponding to a long-time cycle of sixty or sixty- — one years, the culminations being in 1728, 1787, 1847 and 1908. As previously noted, these periods correspond also to times of maximum sun-spot frequencies. 2. Field Columbian Museum, Chicago.—The following. are recent publications : | : No. 129. Geological Series. Vol. III, No. 7. Notes on Vari- ous Minerals in the Museum Collection ; by Ottver Cummines FarRincron, Curator, Department of Geology, and Epwin Warp TitLoTson, JR. Pp. 131-163, 6 figures, plates xliv-liv. Among the species described and figured the following may be noted: Anglesite and olivenite from the Tintic District, Utah ; anglesite, linarite and mimetite from Eureka, Nevada; bertrandite from Albany, Me. ; orpiment and realgar from Mercur, Utah. Publication 133. (Field Museum of Natural History.) Report Series. Vol. III, No. 3. Annual Report of the Director, FREp- ERIcK J. V. Sgirr, to the Board of Trustees for the year 1908. Pp. 216-323, plates xxxili—xliii. 3. Hormeln und Hilfstafeln fir Geographische Ortsbestim- mung; von Tu. Arprecut. Vierte Auflage. Pp. viii, 348. Leipzig (Wm. Engelmann).— A complete exposition of the theory and practice of Geodesy. This is the standard work on this sub- ject, and is indispensable to computers. It is divided about equally between the tables and the discussion of formule and their development. W. B. 4. An Astronomers Wife; by her son, ANGELO Hatt. Pp. 129. Baltimore (Nunn and Co).—This is the biography of Angeline Hall, wife of Asaph Hall, a woman of the pioneer stock of West- ern New York, of lofty character, unusual mental power, and the worthy helpmeet of a great scientist. WwW. B. 5. Comparison des Anciennes Meures; by Jean Mascart, Astronomer in the Observatory of Paris. Pp. 5, from the Bulle- tin of the Astronomical Society of France, August, 1808.—Vari- ous tables of length, weight, etc., published originally in a volume of 500 pages by Robustel and Charles Osmont. “ Ingé- nieurs du Roi pour les instruments de mathématique,” Paris, 1725, and here reprinted as of historical interest. WwW. B. INDEX. TO: VOLUME | XX sie A Abstammungslehre, Steinmann, 341. Academy, National, meeting at Washington, 418. Adams, C. F., Physics, 339. Adirondacks, ice-movement in Southwestern, Miller, 289. Africa, diamonds in German South- western, 489. — Flora of, Thonner, 344. Alaska, Yakutat, coastal plain of, Blackwelder, 459. Algebra, Milne, 272. , Allegheny Observatory, tions, 270, 420. . Allen, E. T., diopside, calcium and magnesium metasilicates, 1. Alpen im Hiszeitalter, Penck Brickner, 341. Aluminum cell as a condenser, Mod- zelewski, 338. Andrews, L. W., determination of arsenic, 316. Animal Romances, Renshaw, 193. Antarctic Expedition, National, 271. Arkansas, Pleistocene bone deposit, 93 publica- and Ashman, G. C., radio-activity of thorium, 65. Association, American, meeting at Baltimore, 100. Astronomer’s Wife, Hall, 493. Astronomy, Spherical, Ball, 270. Atmospheric electricity, observa- tions in, Dike, 197. B Babbitt, J. B., Physical History of the Earth, 91. Ball, R., Astronomy, 270. Barus, C., coronas with mercury light, 73; absence of polarization in artificial fogs, 402. Bateson, W., Mendel’s Principles of Heredity, 491. Bauer, L. A., Magnetic Tables and Charts of the U. S., 263. Bayliss, W. B., Nature of Enzyme Action, 100. Beyer, F. B., eiectrolytic estimation of lead and manganese, 909. * This Index contains the general heads. Blackwelder, E., Yakutat coastal plain of Alaska, 459. Bosworth, R. S., determination of silver as chromate, 241; iodomet- ric estimation of silver, 302. Botanical Station, Harvard, in Cuba, 94. BOTANY and BOTANICAL WORKS. Agriculture of the Dutch East Indies, 192. Blitenpflanzen Afrikas, Thonner, 344, Botanist on the Amazon and Andes, Spruce and Wallace, 266. Botany, mechanical problems, Sch- wendener and Holtermann, 345. Clearing and mounting agent, 96. Flora, Forest, of New South Wales, Maiden, 191, 418. Flower Pollination, Knuth and Davis, 96. Plant Study, Meier, 345. Trees, Ward, 491. Bradley, W. M., composition warwickite, 179. British Guiana, Gold Fields of, Har- rison, 409. British Museum, Catalogue, 492. Brooklyn Institute of Science, 420. Browning, P. E., Rarer Elements, 262; estimation of thallium, 3879. Briickner, E., die Alpen im Kis- zeitalter, 341. Bush, K. J., notes on the family Pyramidellide, 475. of C. California earthquake of 1906, Gil- bert, 48. Canada geol. survey, 87. Canal rays, see Rays. Carnegie Foundation, 3d Ann. Re- port, Pritchett, 346. Carnegie Institution of Washington, publications, 267, 547. Chemical Analysis, Qualitative, Tower, 486. BOTANY, CHEMISTRY (incl. chem. physics), GEOLOGY, MINERALS, OBITUARY, ROCKS, ZOOLOGY, and under each the titles of Articles referring thereto are mentioned. INDEX. CHEMISTRY. Argon, compound of, Fischer and Tliovici, 82. Arsenic, determination, and Farr, 316. ‘Atomic weight, new periodic func- tion, Viktor, 186. Boron, determination, Copaux and Boiteau, 404. Calcium and magnesium metasili- cates, relations, Allen and White, Cerium, determination, 260. Copper oxalate in analysis, Gooch | and Ward, 448. Crystallization, explosive, Weston, 82 Cupric chloride, gases evolved by action on steel, Goutal, 485. Gold, solubility in hydrochloric acid, Awerkiew, 261. Helium, production from uranium, Soddy, 262. Hydrogen phosphide, Matignon and Trannoy, 337. — silicides, Lebeau, 404. Lead, electrolytic estimation, Gooch | and Beyer, 59. Manganese. electrolytic estimation, Gooch and Beyer, 99. Metals, boiling-points, Krafft, 336. Potassium salts, radiation, Henriot, 486. Prussian blue, Miller and Stanisch, 403. Radium, see Radium. Selenium, electric properties, Ries, 338. Silver, determination as chromate, Gooch and Bosworth, 241. —ijiodometric estimation, Gooch and | Bosworth, 302. Sodium and _ potassium, alloys, Jaubert, 260. Thallium, estimation, Browning and Palmer, 379. Thorium, radio-activity, Ashman, 69. . Tin, heat of oxidation, Mixter, 229. ‘Tin infection,” von Hasslinger, 83. Titanium oxide, heat of formaticn, Mixter, 393. Tungstic and silicic oxides, separa- tion, Defacqz, 186. Uraniam silicide, Defacqz, 186. Uranium-X, Schmidt, 187. Vanadic acid, iodometric tion, Edgar, 174. liquid estima- Andrews | Dietrich, | 495 Vanadium and arsenic acids, esti- mation, Edgar, 299. Weight, change of, in reactions, Landolt, 185. Vtterbium, constituents, von Wels- | bach, 83. Chemistry, Organic, Stewart, 337. Chlorophyll on planets, existence, Umow, 487. |Coal and coal-mining, geology, Gibson, 91. 'Cockerell, T. D. A., Tertiary insects, 53, 381. Connecticut geol. survey, 264. Cook, C. W., iodyrite from Tono- pah and Broken Hill, 210. Coronas with mercury light, Barus, 73. Cuba, Harvard Botanical Station, 94. | D Dahlgren, W., Animal Histology, 97. Diamonds in Africa, 489. Dike, P. H., observations in atmos- pheric electricity, 197. Diller, J. S., geology of Taylorsville | region, Calif. Al _ Diopside, relation to calcium and | magnesium metasilicates, Wright | and Larsen, 1. ‘Duff, A. W., Physics, 85; Physical | Measurements, 488. | Duncan, D., Life of Herbert Spencer, 99. E _Earth, Physical History, Babbitt, 91. |Earthquake, California, 1906, Gil- bert, 48. — Messina, Perret, 321. ma ras magnetism, principal facts, 348. Eastman, C. R., Devonian Fishes of | Towa, 415. Edgar, G., iodometric estimation of vanadic acid, 174; estimation of _ vanadic and arsenic acids, 299. |Electricity, atmospheric, recent ob- servations in, Dike, 197. Elements, Rarer, Browning, 262. Enzyme action, Bayliss, 100. Eruptions, submarine, near Pantel- leria, Washington, 1381. Evolution, Essays on, Poulton, 193. — work on, Steinmann, 341. Ewell, A. W., Physical Measure- ments, 488. 496 F Farr, H. V., determination of arsenic, 316. | Field Columbian Museum, publica- tions, 493. Fletcher, L., Study of Rocks, 490. | Foote, W. M., Mineral Catalogue, 490. Ford, W. E., neptunite crystals, | California, 235. Fossil, se GEOLOGY. Franklin, W. S., Physics, 85. Friend, J. N., Theory of Valency, D071. | G Gases in Rocks, Chamberlin, 190. Gaskell, W. H., Origin of Verte- brates, 192. Geographical Tables, Albrecht, 493. | GEOLOGICAL REPORTS. Canada, publications, 87. Connecticut, 264. Illinois, 1907. 89; Bulletin No. 9, 489. : Indiana, 32d Ann. Report, 88. | Iowa, 339. | Mississippi, 264. New Jersey, 189. | New Zealand, 89. North Carolina, 87. Oklahoma, 339. | United States, list of publications, | 86, 406. — 29th Ann. Report. Vermont, 1907-8, 188. Western Australia, 341. Wisconsin, 489. GEOLOGY. | Cambrian geology, Walcott, 414. Carboniferous Crustacea of Scot- land, Peach, 488. Cervide, osteology of American, | Matthew, 93. Chalicotheres, American, Peterson, 94. Chalk formations of Texas, Gordon, 569. Devonian of Central Missouri, Gre- ger, 374. — fishes of lowa, Eastman, 415. Earth, Physical History, Babbitt, 91. Earthquake, see Earthquake. Erosion, study of, Leverett, 349. Fauna, Guadalupian, Girty, 413. Georgetown quadrangle, Gibbs, INDEX. *, ‘ Fossil insects, Handlirsch, 268 ; Cockerell, 53, 381 ; Sellards, 151. Fossils from Silurian of Tennessee, Foerste, 489. Fulgur, genesis, Maury, 339. Georgetown quadrangle, Colorado, seo O8y, Spurr, Garrey and Ball, Glacial bowlders in Blaini forma- tion, India, Holland, 4138. gy ae in New York, Fairchild, Glaciation of the Uinta and Wa- satch Mts., Atwood, 340. Heidelberg man, 416. Horses, fossil, No... Dakota and Montana, Douglass, 94. age and erosion, Miller, Ichthyosauria, Triassic, Merriam, Sie Lakes, divided, in Western Minne- sota, Griggs, 388. Oligocene lizards, Douglass, 94. Permian insects, Sellards, 101. Pleistocene bene deposit, Arkansas, Brown, 93. : Protostegidz, revision, Wieland, 101. Rhinoceros, fossil, from No. Dakota and Montana, Douglass, 93. Saurian, armored, from the Nio- brara, Wieland, 250. Silurian fossils, Tennessee, Foerste, 489. Taylorsville region, Calif., geology, Diller, 412. Tertiary insects, Cockerell, 53, 381. Tetraceratops from Texas, Matthew, 93. cte., Time measures, weathering and erosion as, Leverett, 349. Turtles, fossil, Wieland, 101. Vertebrates, fossil, in the Amer. Museum Natural History, Cata- logue, Hussakof, 92. Volcanoes of St. Vincent and Mar- tinique, Anderson and Flett, 89 ; Vesuvius, Johnston and Lavis, 410. Yakutat coastal plain of Alaska, Blackwelder, 459. Zonal Belt Hypothesis, Wheeler, 260. ; geology, Spurr, Garrey and Ball, 408. Wolcott, obituary notice, Jackson, 2955. Gilbert, G. K., California earthquake of 1906, 48. INDEX. Girty, Guadalupian fauna, 413. Glacial, Glaciation, see GEOLOGY. Goniometer lamp, new, Wright, 194. | Gooch, F.A., electrolytic estimation | of lead and manganese, 59; deter-_ 241 ; | mination of silver as chromate, iodometric estimation of silver, 302 ; copper oxalate in analysis, 448. Gordon, C. H., northeast Texas, 369. Greger, D. K., Devonian of central Missouri, 374. Griggs, R. F., divided lakes in western Minnesota, 388. Groth, P., Chemische graphie, 260. Guadalupian Fauna, Girty, 418. Guiana, son, 409. — Dutch, geology, Beekman, 410. Krystallo- H Handlirsch, A., Fossil Insects, 263. Harvard Botanical Station in Cuba, 94. — College Observatory, 269, 420. Hatch, F. H., Petrology, 410. Hauswaldt, H., Interference phenom- ena, 490. Headden, W. P., brown artesian waters of Costilla Co., Colo., 305. Heredity, Mendel’s Principles, Bate- son, 491. Himalaya Mts. and Tibet, Burrard and Hayden, 189. Hintze, C., Mineralogie, 265. Hoadley, G. A., Physics, 339. Homo Heidelbergensis, Schoeten- sack, 416. I Ice-movement and erosion, Miller, 289. Idaho, geology and ore deposits, Ransome and Calkins, 90. Illinois geol. survey, 89, 489. India, commercial products, ALT. Indiana geol. survey, 88. Insects, fossil, Handlirsch, 263, — Permian, Sellards, 151. — Tertiary, Cockerell, 53, 381. Interference phenomena, Hauswaldt, 492. Ion, new Journal, 98. Ionization of gases, Rausch, 187. Iowa, Devonian fishes, Eastman, 415. — geol. survey, 339. Watt, chalk formations of | British, gold fields, Harri- | 497 J _Jackson, C. L., obituary notice of Wolcott Gibbs, 258. Johannsen, A., Rock-forming Miner- als, 490 K Repel W. A., Animal Histology, 97. Knuth, P., Bliiten-biologie, 96. Kraft, Reyer, 272. Kraus, E.H., iodyrite from Tonopah and Broken Hill, 210. | Krystallographie, Chemische, Groth, | 260. 1b | Lakes, divided, in western Minnesota, Griggs, 388. | Larsen, E. S., optical study of diop- side, etc., 28; quartz as a geologic thermometer, 421. Leverett, F., weathering and erosion as time measures, 349. Library of Congress, Report, 269. Light, for microscope, Wright, 98; sources of monochromatic, Wright, 195. Losungen, Feste, Bruni, 262. M Magnetic properties of steel, Pierce, 273. — tables for United States, Bauer, 268. Magnetism, Earth’s, principal facts, 348. — permanent, of copper, Ross, 268. Man in the Light of Evolution, Tyler, 419, — Heidelberg, 416. Martinique and St. canic eruptions, Flett, 89. Matter, composition of, Mulder, 261. Maury, C. J., genesis of Fulgur, 335. Massie, W. W., Wireless Teleg- raphy, 406. Meier, W. H. D., Plant Study, 345: Mendel’s Principles of Heredity, Bateson, 49). Merriam -).7C* osauria, 91. Merrill, G. P., composition of stony meteorites, 469. Merwin, H. E., alamosite from Mex- ico, 399. 1905, Gray and Vincent, vol- Anderson and Triassic Ichthy- 498 Messina earthquake, Perret. 321. Meteorites, stony, composition, Mer- rill, 469. Michelson’s ether research, Kohl, 308. Microscope, artificial daylight for use with, Wright, 98. Miller, W. J., ice-movement and | erosion in Adirondacks, 289. Milne, W. J., Algebra, 272. Mineral Catalogue, Foote, 490. — Collections, Prendler, 343. Mineralogie, Hintze, 265. Mineralogy, Optical, N. H. and A. N. Winchell, 412. MINERALS. Alamosite, Mexico, 399. Benitoite, crystal form, 3598. Diamonds in Africa, 489. Diopside, ils Hollandite, 344. Todyrite, Nevada, 210; New South Wales, 212. Jadeite, Upper Burma, 343. Neptunite crystals, Calif., 235. Pyrite, crystals, Utah, 467. Quartz, as geologic thermometer, 421. : Rubies, Upper Burma, 344. Warwickite, composition, 179. Minerals, Rock-forming, Johannsen, 490). Minnesota, 088. Mississippi geol. survey, 264. Missouri Devonian, Greger, 374. divided lakes, Griggs, Mixter, W.G., heat of oxidation of | heat of formation of | tin, 229; titanium oxide, 393. Molecular attraction, electric origin, Sutherland, 487. Mount Stephen rocks and fossils, Walcott, 414. Mount Weather Observatory, bul- letin, 270, 492. N New Jersey geol. survey, 189. New York, glacial waters in central, Fairchild, 340. New Zealand geol. survey, 89. Nichols, E. L., Physics, 85. North Carolina geol. survey, 87. OBITUARY. Ayrton, W. E., 100. Frazer, P., 420. Gibbs, W., 100, 258. { INDEX. Hough, G. W., 196. Seeley, H. R., 272. Observatory, Allegheny, 270, 420. - — Harvard College, publications, 269, 420. — Mt. Weather, 492. — Washburn, 270. Oklahoma geol. survey, 389. Osborn, H., Economic Zoology, 97. P Palache, C., benitoite, 398; alamo- site from Mexico, 399. Palmer, H. E., estimation of thal- lium, 379. Parasitology, 194. ee A., die Alpen im Hiszeitalter, 41. Perret, F. A., Messina earthquake, 321. Petrology, Hatch, 410. Physical measurements, Duff and Ewell, 488. Physics, Adams, 339 ; Hoadley, 339. — Elements, Nichols and Franklin, 89. — Text-Book, Duff, 85. Physiologie, Allgemeine, Verworn, 419 Pierce, B. O., permeabilities and reluctivities for steel, 273. Plimmer, R. H. A., Chemical Con- stitution of Proteins, 271. Polarization, absence in artificial fogs, Barus, 402. Positive rays, Wien, 84. Potential in dark cathode space, Westphal, 84. Poulton, E. B., Essays on Hvolution, 193. - Prisms, deviation of rays by, Uhler, 9 Proteins, Chemical Constitution, Plimmer, 271. R Radiation investigations, Coblentz, 188. Radio-active elements, chemistry, Strémholm and Svedberg, 404. | Radio-activity, Raffety, 406. — of thorium, Ashman, 65. Radiometer for observing pressures, Dessar, 405. Radium, a particle from, Rutherford and Geiger, 262. — heat evolved by, von Schweidler and Hess, 83. — emanation, Rutherford, 185, 336 ; condensation of, Rutherford, 487; small INDEX. liquid and solid, Gray and Ramsay, | 485. Raffety, C. W., Radio-activity, 406. | -Rays, canal, Stark and Stenberg, 84, 405. — of high penetrability, Wulf, 405. — positive, Wien, 84; Doppler effect in, Trowbridge, 245. — Rontgen, velocity, Marx, 187. Renshaw, G., Animal Romances, 193. | Reyer, Kraft, 6konomische, etc. , 272 ROCKS. - Composition of with stony metorites, 469. Dutch Guiana, petrography, Beek- man, 410. Gases in rocks, Chamberlin, 190. Plutonic rocks, Hatch, 411. Study of, Fletcher, 490. Rogers, A. F., pyrite crystals from Utah, 467. Rontgen rays, velocity, Marx, 187. SS) Scienza, Rivista di, 100. Sellards, E. H., types of Permian insects, 151. Smithsonian Institution, report, 196. Spark spectra, Berndt, 187. Spencer, Herbert, Life and Letters, Duncan, 99. Steel, permeabilities and reluctivi- ties, Pierce, 275. Steinmann, G., Geol. Grundlagen der | Abstammungslehre, 341 Stewart, A. W., Organic Chemistry, | 307. E Texas, chalk formation, Gordon, 369. — Pelycosaurian from, Matthew, 93. Thermoelectric force, influence of pressure upon, Horig, 338. Thermometer, Wright and Larsen, 421. Thorium, radio-activity, Ashman, 65. Topographic Maps, Salisbury and Atwood, 265. Tower, O. F., Qualitative Chemical Analysis, 486. Trowbridge, J., Doppler effect in positive rays, 245. Turkestan, Exploration, Pumpelly, 4138. ebyler;- J. Evolution, 419. ‘7 wlan. | classification, | quartz as geologic, | M., Man in the Light of | 499 U |Uhler, H. S., deviation of rays by prisms, 223. Uinta Mts., 340. Underhill, C. R., Wireless Teleg- raphy, 406. | mee States Coast Survey, report, — Geol. survey publications, 86, 406 ; 29th Annual Report, 188. — magnetic tables, Bauer, 263. glaciation, Atwood, rocks compared | Merrill, V Valency, Theory of, Friend, 337. Vermont geol. survey, 88. | Vertebrates, Origin of, Gaskell, 192. _Verworn, M., Allgemeine Physio- logie, 419. | Vesuvius, eruption April 1906, John- ston-Lavis, 410. Volcanoes, see GEOLOGY. W Ward, H. L., copper oxalate in analysis, 448. Ward, H. M., Trees, 491. Washburn Observatory, publica- | tions, 270. Washington, H. §S., submarine eruptions near Pantelleria, 131. Water, amount in cloud, 262. Waters, artesian, of Costilla Co., Colorado, Headden, 305. — ground, of the Indio region, Cali- fornia, Mendenhall, 340. |Watt, G., Commercial Products of |. India, 417. |Weathering and erosion as time- measures. Leverett, 349. Western Australia geol. survey, 341. Wheeler, J. T., Zonal Belt Hypothe- sis, 260. | White, W. P., diopside, calcium and magnesium metasilicates, 1. Wieland, G. R., revision of the Pro- tostegidze, 101. —armored saurian from the Nio- brara, 290. Winchell, N. H. and A. N., Optical Mineralogy, 412. Wireless Telegraphy, Underhill, 406. Wisconsin geol. survey, 489. Wright, F. E., optical study of diop- side, etc., 28; artificial light for microscope, 98; new goniometer Massie and 500 INDEX. lamp, 194; sources for monochro- | matic light, 195; quartz as a geo- logic thermometer, 421. Ze Zeeman effect, Dufour, 338 ; Gmelin, 405. ZOOLOGY. Animal Histology, Dahlgren and Kepner, 97. Animal Romances, Renshaw, 198. Economic Zoology, Osborn, 97. Lepidoptera Phalene in the British Museum, Hampson, 492. — Pyramidellidz, notes on the family, Bush, 475. o's Ticks, monograph on, 193. Vertebrates, Origin, ~Gaskell, 192. Zellforschung, Archiv fiir, 97. See also GEOLOGY. Am. Jour. Sci., Vol. XXVII, 1909. Plate I, Photomicrographs. a Artificial diopside. Etch pits on 110 produced by action of hot com- mercial HF for 40 seconds. Magnification 200 diameters. 6 Artificial diopside. Etch pits on 110. Exposed to hot commercial HF 40) seconds. Magnification 250 diameters. e Etch pits on 110 of crystal MgSiO; 50 per cent, CaSiO; 50 per cent. Time of exposure 40 seconds in hot commercial HF. Magnification 220 diameters. : d Etch pits on 110 of crystal MgSiO; 50 per cent, CaSiO; 45 per cent. Time of exposure in hot commercial HF’, 40 seconds. Magnification 440 diameters. e Etch pits on 110 Mg-pyroxene (6-MgSiO;). Exposed 50 seconds in hot commercial HF. Magnification 1065 diameters. f Etch pits on 110 of crystal MgSiO,; 75 per cent, CaSiO; 25 per cent. Exposed 40 seconds in hot commercial HF. Magnification 230 diameters, Arm.sour. oci., Vol. XXVIII, 1909. Plate II. ES AS I Archelon ischyros Wieland.—Photograph of dorsal view of the type as mounted in the Yale University Museum. (Compare with text figure 7.—The right flipper was bitten away just above the heel early in life by some predaceous enemy, either a shark, a fish or a mosasaur.) Am. Jour. Sci., Vol. XXVII, 1909. Plate Ill. | ES WADE aria ahaha besSaibapesteiaieE j j ; Archelon ischyros Wieland.—Photograph of ventral view of the type as now on exhibition in the Yale University Museum, (Cf, text figure 8, and compare with the preceding plate.) a ar fo tp est aie ie Am. Jour. Sci., Vol. XXVII, 1909. Plate IV. Archelon ischyros Wieland.—Photograph of lateral view of the type as now mounted in the Yale University Museum. [Plastron in approximate position. | New Circulars. 84: Eighth Mineral List: A descriptive list of new arrivals, rare and showy minerals. 85: Minerals for Sale by Weight: Price list of minerals for blowpipe and laboratory work. 86: Minerals and Rocks for Working Collections: List of common minerals and rocks for study specimens; prices from 1% cents up. Catalogue 26: Biological Supplies: New illustrated price list of material for dissection; study and display specimens; special dissections; models, etc: Szxth edition. Any or all of the above lists will be sent free on request. We are constantly acquiring new material and publishing new lists. It pays to be on our mailing list. Ward's Natural Science Establishment 76-104 Cotiece AVE., Rocuestrr, N. Y. Warns Natura Science EstaBisHMeENt A Supply-House for Scientific Material. Founded 1862. Incorporated 1890. DEPARTMENTS: Geology, including Phenomenal and Physiographic. Mineralogy, including also Rocks, Meteorites, etc. Palaeontology. Archaeology and Ethnology. Invertebrates, including Biology, Conchology, ete. Zoology, including Osteology and Taxidermy, Human Anatomy, including Craniology, Odontology, ete. Models, Plaster Casts and Wall-Charts in all departments. Circulars in any department free on request; address Ward's Natural Science Establishment, 76-104 College Ave., Rochester, New York, U.S, A. CONTENTS. Art. XXXVIII.—Quartz as a Geologic Thermometer ; by F. EB. Weieut and.E. 8. Larsen. 2.2.2.1. 2 eae 421. XXXIX.—Precipitation of Copper Oxalate in Analysis; by K, A. Goocw and-H. L. Warp ____ 2.2.22) 2 XL.—Yakutat Coastal Plain of Alaska; A combined ter- restrial and marine Formation ; by E. BhackWELDER _ 459 XLI.—Pyrite Crystals from Bingham, Utah; by A. F.. RoGurs 220i. 2 ee 467 XLII.—Composition of Stony Meteorites compared with that of Terrestrial Igneous Rocks, and considered with reference to their efficacy in World-Making; by G. P. MBRRILL2o {202 he deeee a ee 469 XLIT.—Notes on the Family Pyramidellide; by K. J. BusH, Pu.De oe oe eo. Ie AT5 SCIENTIFIC INTELLIGENCE. Chemistry and Physies—Liquid and Solid Radium Emanation, Gray and Ramsay: Gases Evolved by the Action of Cupric Chloride upon Steels, GouTAL, 485.-—Radiation of Potassium Salts, E. Hmnriot: Course of Qualitative Chemical Analysis of Inorganic Substances, O. F. Tower, 486.— Suggested Method of Ascertaining the Existence of Chlorophyll on Planets, N. Umow: Condensation of the Radium Emanation, RUTHER- FORD: Electric Origin of Molecular Attraction, W. SUTHERLAND, 487.— Physical Measurements, A. W. Durr and A. W. Ewe tt, 488. Geology and Natural History—Monograph on the Higher Crustacea of the Carboniferous Rocks of Scotland, B. N. Pracu, 488.—Fossils from the Silurian Formations of Tennessee, Indiana and Illinois, A. F. FOERSTE : Illinois State Geological Survey, C. W. Routrs, R. C. Purpy, A. N. TaL- Bot and I. O. BakER: Wisconsin Geological and Natural History Survey, ii. A. BircE and W. O. Horcuxiss: A new Locality of Diamonds in Africa, HK. Kaiser, 489.—Interferenzerscheinungen im polarisirten Licht, H. HAvUswaLpT: Ccmplete Mineral Catalog, W. M. Foore: Introduction to the Study of Rocks, L. FLtercHmr: Determination of Rock-forming Min- erals, A. JOHANNSEN, 490.—_Trees, A Handbook of Forest Botany for the Woodlands and the Laboratory, H. M. Warp: Mendel’s Principles of Heredity, W. Batrson, 491.—Catalogue of the Lepidoptera Phalenz in the British Museum, Vol. VII; Catalogue of the Noctuide, G. F. Hamp- son, 492. Miscelluneous Scientific Intelligence—Bulletin of the Mount Weather Obser- vatory, 492.—Field Columbian Museum, Chicago: Geographical Tables, AuBRecHT: An Astronomer’s Wife, A. Hatt: Anciennes Meures, Mas- CART, 498. InpEx, 494. g13¢ i 4 I et ee SMITHSONIAN INSTITUTION LIBRARIES TNA | 3 9088 01298 5784