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FAI 00 wh the htm AL Vat Nokes, 2 +: Wet z Srvrorre mes carrey , . v bparite an ae a ed é . yah tate (ROTA e tb gt Crd BOERS cae ENN . : , F LAPTG Te A dae oe ererepoly aaah a + hal ° VOU OO oo ol oh ohn Budo! ote, ; Dabs tee tb SV adhe, tate ; Ree MEA Memon son en re tele diner - ree : ; ae . p b “eRe Pate she tehe Bone Gy sal ici tip oe ia % ; A rw as Fre, Taha hog 9 ce metre a ; re N abn ioe : 3 : r pote Tete heey oe A en ek ee ae . cs G “ PAD LAD omy ~tmwS ~¥e. . seer WV ETN mS, Det wy obs ’ is - < Se eR be CEN Verte ing C . os Fete Reh, “ aie wees wses 40 on? ‘ frente were re Re Stet Preah beh itetngm, se Gente! Ney Tae Yen gay ig ts : aise . SENN M es bee we kee y . * een ee aebeiel cl rae ; “ a ‘ . aye Lhe eet de eh etd Pa ee i +e Sevens wh eh ed of leh ah pt Foal 7 : - ee PPR tere om o.: Te ee ee ‘ tee ° SRE ee te Beet, sie ete Rnb od " ae s 1 ede: Pal pn wate ae ro AWOL, ete cAy Men Ne’ " bodied tint nee ” oe! ate mo See mS metietes . tha Seer ePie hatte oe Ney Mas Raga oo bok Fea ne, . . 2 terme +. % i fs Bs an Eva ON 2 age [= 3 oe a Set St \ Saeed FTA Nae ite 6 Hoare anda uno | 5S Soa ee : i: es ‘ LD ars Ba Seas af zt 7. noth aes te BN TA 5 y ; oS) 4 rH ay ~ ose ort : ! MO, » ne a a ae cay = sa es i Be ae a aay yeh oe rer *, ne ht sia? “ ae ERAN. ference te ee ab ahi $f L oie Ho] sel “ty el Wie A gpany fs u iin fea ‘ Y GST acne pra #| as aa “Steer S ‘c Spor LS £9 Stas Ea ae “ ee era na ea a eee ae rey — = eens Pr ES : a ne Pace tT a i e ; he a YT: sal is ES oS 4 aie Ki — \. aati eas i in Se THE AMERICAN JOURNAL OF SCIENCE. Epviror: EDWARD S. DANA. ASSOCIATE EDITORS Proressors GEORGE L. GOODALE, JOHN TROWBRIDGE, anp WM. M. DAVIS, or Camprines, _ Prorgssors A. E. VERRILL, HORACE L. WELLS, CHARLES SCHUCHERT, L. V. PIRSSON, H. E. GREGORY, anp HORACE 8S. UHLER, or New Haven, Prorrssor JOSEPH 8S. AMES, or Batrtimorg, Mr. J. S. DILLER, or Wasuineron. FOURTH SERIES VOL. XLVHI—[WHOLE NUMBER, OXCVIIT). NEW HAVEN, CONNECTICUT. 1 es THE TUTTLE, MOREHOUSE & TAYLOR COMPANY NEW HAVEN CONTENTS TO VOLUME XEVIIL Number 288. Page Art. I.—Present Tendencies in Paleontology; by E. W. pyENEAER NG, AEN ann) MR eie WAN UME Net fic" o ¢ alae sik bee bes if Arr. IJ.—Comanchean Formations underly‘ng Florida; by Pe SAR DS ec i seb tom dy St ahe 2 Ned. 13 Art. III.—Studies in the Cyperaceer; by T. Horm. XXVII. Notes on Carex podocarpa R. Br., C. Montanensis Bail., C. venustula Holm, C. Lemmonit W. Boott, and C. equa Clarke. (With 12 figures drawn from nature by the SeTCEINOTE| Se Lp eRe) OUR «CAREER Seg: (CS OREN, coe ls AN iG Arr. [V—On Atavism and the Law of Irreversibility; by 18 GUSTIDIS Lia SENSIS Saati i de eh AA tesa ik Maer Rey Petre ae eR ea a0 Arr. V.—On a Possible Limit to Gravitation; by F. W. TEER dae: a a eae Ce PT See oe Ce an ee ay 33 Art. VI.—Some Problems of the Adirondack Precambrian; aired ap eNO en ee A a eS Mik GS beara. ay 47 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Arrangement of Electrons in Atoms and Molecules, I. Lanemuir, 69.—Qualitative Chemical Analysis, W. W. Scort: The Origin of Spectra, J. J. THomson, 70.—Absorption of X-Rays, T. E. AuvriEn, 72.—Experimentelle Untersuchungen tiber die Beugung elek- tromagnetischer Wellen an einem Schirm mit geradlinigem Rande, M. Ss6stROM, 73.—Mechanical Theory of the Vibrations of Bowed Strings and of Musical Instruments of the Violin Family, with Experimental Verification of the Results, part I, C. V. Raman, 74. Geology—United States Geological Survey, G. O. Smita, 75.—Publications of the U.S. Bureau of Mines, Van H. Mannine: lowa Geological Survey, G. F. Kay: Virginia Geological Survey, T. L. Watson, 77.—Geological Survey of Illinois, F. W. DEWo.trF: North Carolina Geological and Economic Survey, J. H. Pratt: Wisconsin Geological and Natural His- tory Survey, HK. A. Brrer and W. O. Horcukiss: Om Skanes Brachiopod- skiffer, G. T. TRoEDsson, 78. Miscellaneous Scientific Intelligence—EKquilibrium and Vertigo, I. H. Jonzs, 79. Obituary—W. G. FaRiLow, 80. 1V CONTENTS. Number 284: Page Art. VIJ.—The Ternary System CaO-MgO-Si0,; by J. B. recusen and H. EH. Murwin: 02.). 2222/0. eee 81 Art. VIII.—Some Notes on Japanese Minerals; by Suim- watsu [onmawa. ... 2550... 0 08) oo rrr 124 Art. [X.—Additional Facts Relating to the Granite Bowl- ders of Southeastern Kansas; by W. H. Twrnuorer... 132 Art. X.—The Coral-Reef Zone During and After the Glacial __ Period; ‘by Tk. A: DALY 3.25) 3257. fe eee 136 SCIENTIFIC INTELLIGENCE. Chemistry—A System of Physical Chemistry, W. C. McC. Lewts: An Introduc- tion to the Physics and Chemistry of Colloids, E. HatscHeK: Colloidal Chemistry, J. ALEXANDER, 160.— Chemical Calculation Tables for Labora- tory Use, H. L. WELLs, 161. Geology and Natural History—The U. 8S. Geological Survey, its History, Activities and Organization: Manual of the Chemical Analyses of Rocks, H. S. WasuHinaton, 161.—A Source Book of Biological Nature-Study, E. R. Downine: Problems of Fertilization, F. R. Linus, 162. Miscellaneous Scientific Intelligence—Division of Geology and Geography of the National Research Council: Recent Publications of the Carnegie Institution of Washington, 163.—New Outline Map of the United States on the Lambert Projection, 164. CONTENTS. v Number 285. Page Art. XI.—Wollastonite (CaO.Si0,) and related Solid Solu- tions in the Ternary System Lime-Magnesia-Silica; by J: Bb: Burcuson and Wi. HM) MuRwin ..........5..25:. 165 Arr. XII.—The Extent and Interpretation of the Hogshooter Seersand: (bie We. iv) bHREMR. WU! Soe oe ede ede. 189 ‘Arr. XJII.—Abnormal Birefringence of Torbernite; by N. HEV OMNCHAN Pigs 27RNe MANES te soot fd eae data ile aS aie 195 Arr. XIV.—Organic Structures in the Biwabik Iron-bearing Formation of the Huronian in Minnesota; by F. F. Cuoun and lo BRODERICK ..G' fel os 5 deol a se ee es 199 TELOT PGT Se ASG 178 egies Mn doen Ain Ea i oe 206 Art. XVI.—Note on the Depth of the Champlain Submer- gence along the Maine Coast; by P. W. Musrerve.... 207 Art: XVII.—On the Correlation of Porto Rican Tertiary Formations with other Antillean and Mainland Horizons; ie CARL OME OLOUENA MAURY 6). 0 «2a 5 2)ejew eae e sjelee ol 209 Art. XVIII.—Geological Notes on the Pribilof Islands, Alaska, with an Account of the Fossil Diatoms; by G. a, TBRURGSCINCA VS yp cal nie Stak ae a tea ete De Tee BES vm 261 Art. XIX.—The Framework of the Harth; by W. M. Davis 225 CHnonecn HMRDINAND DHOKER .. ose. ccs os ce ob wee bee 242 SCIENTIFIC INTELLIGENCE. Geology—Geology and Ore Deposits of Tintic Mining District, Utah, W. Linp- GREN and G. F. LouGHLIN: Genesis of the Ores at Tonapah, Nevada, H. S. Bastin and F. B. Laney, 246—Review of Geology and connected Sciences, 247. Miscellaneous Scientific Intelligence—The Whole Truth about Alcohol, G. E. Fuint, 247.—The Blind; their Condition and the Work being done for them in the United States, H. Brest: Colloids in Biology and Medi- cine, H. BecHHoLD, 248.— Aeronautics: United States Coast and Geodetic Survey, 249. Obituary—Lorp RAYLEIGH, 249.—E. H. HarckeL: P. CHorrat, 250. vi CONTENTS. Number 286. Page JOSEPH BARRELL (1869-1919) ..... brie neti 251 Art. XX.—The Nature and Bearings of Isostasy; by JosmpH ‘BARREGE. 2 +20". Sane «enol ee Or 281 Art. XXJI.—The Status of the Theory of Isostasy; by 291 JosupH .BARRELI. ooo). Oo Ae ee eee CONTENTS. Vii Number 2387. Page Arr. XXII.—Pre-Cambrian and Carboniferous Algal Depos- BONN slic Fe WRI ELOR BL rc oaths Sm ae recs «cs dae 339 Art. XXIIJ.—On Ferrazite? A new associate of the Dia- mond ; by T. H. Leer and Luiz Fiores pE Morass... 353 Art. XXIV.—The Hackberry Stage of the Upper Devonian coemlemarny Oh h WN RON i so o's occ tes Sse ie ee 395 ArT. XX V.—Tactite, the product of Contact Metamorphism ; Dae U9 io cl 6 OSG eo Oh Dies eerie Bete ee og BR ac ee a 377 Art. XX VI.—Structural Features of the Abajo Mountains, reams the ORE bs soe ey ols So ae wine yg op 379 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—The Single Deflection Method of Weighing, P. H. M.-P. Brinton, 390.—A Method of Growing Large Perfect Crystals from Solution, R. W. Moore: Modifications of Pearce’s Method for Arsenic, 391.—New Fluorescent Screens for Radioscopic Purposes, P. ROUBERTIE and A. NEMIROVSKY: Scattering of Light by Solids, R. J. Strutt, 392.— Apparatus for the Direct Determination of Accelerations, B. GALITZIN, 394. Geology—Shore Processes and Shoreline Development, D. W. Jonnson, 395.— World-Power and Evolution, E. Huntineton, 396--Brachiopoda of the Australasian Antarctic Expedition, 1911-1914, J. A. THomson, 397.— Pelecypoda of the St. Maurice and Claiborne Stages, G. D. Harris, 398.— Tertiary Mammalian Faunas of the Mohave Desert, J. C. MERRIAM, 399. Miscellaneous Scientific Intelligence—Thirteenth Annual Report of the Presi- dent, Henry 8. Pritcuert, and the Treasurer, ROBERT A. FRANKS, of the Carnegie Foundation for the Advancement of Teaching, 400.—Publi- cations of the Carnegie Institution of Washington, R.S. Woopwarp, 401.— National Academy of Sciences: The Birds of North and Middle America, R. Ripeway: Biographical notice of Joseph Barrell, CHARLES ScuvcH- ERT, 402. Obituary—F.. Brawn, 402. Vill CONTENTS. Number 288. Page Arr. XXVII.—The Middle Ordovician of Central and South Central Pennsylvania; by R. M. Frenp.....:.. 2 22eeeee 403 Art. XXVIII.—Note on an Unusual Method of Rounding of Pebbles in sub-arid Western Australia; by J. T. Jurson 429 Art. X XI X.—Sheet-flows, or Sheet-floods, and their asso- ciated phenomena in the Niagara District of sub-arid south-central Western Australia; by J. T. Jurson..... 435 Art. XX X.—Cacoclasite from Wakefield, Quebec; by N. L. BOWEN 2.0008 Ee 2 oe Oo oe ote eee er 440 Art. XX XI.—An Interesting Occurrence of Manganese Min- erals near San Jose, Californi ; by A. F. Rocers...... 443 Art. XX XII.—Orthogenetic Development of the Coste in the Perisphinctine; by Marsoriz O’ConneEL1, Ph.D... 450 Arr. XXXIII.—Heterolasma foerstei, a New Genus and Species of Tetracoralla from the Niagaran of Michigan; by G. M.. Wanies 22. 0... 2 eae ee eee 461 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Determination of Zirconium by the Phosphate Method, G. E. F. LunpELL and H. B. Know uss, 467.—An Introductory Course in Quantitative Chemical Analysis, G. McP. Smiru, 468.—Richter’s Organic Chemistry, P. E. Spiztmann: Notes on Qualitative Analysis, L. A. Test and H. M. \!icLauGuuin, 469.—The Chemistry and Manufacture of Hydro- gen, P. L. TEED: Calculation of the Radiation Constants c. and o, F. HEn- winG, 470.—Indices of Refraction for X-Rays, A. Ernsrrein, 471.—The General Polarization Surface, F. JeEntzScH-GRAFE, 472.—Aviation, B. M. Carmina: Molecular Physics, Second Edition, J. A. CROWTHER, 473. Geology and Natural History—Western Australia Geological Survey, T. BLATCHFORD, etc. : New Zealand Institute Science Congress, Christchurch, 1919, 474.—Descriptions and Revisions of the Cretaceous and Tertiary Fish-Remains of New Zealand, F. Coapman: The Prickly Pear in Austra- lia, W. B. ALEXANDER, 475.—United States Geological Survey, G. O. Smitu, 476.—Foliation and Metamorphism in Rocks, T. G. BONNEY ; Observations on Living Lamellibranchs of New England, E. S. Morse: Elementary Biology ; An Introduction to the Science of Life, B. C. GRUEN- BERG, 477. Miscellaneous Scientific Intelligence —National Academy of Sciences, 478. Obituary—J. W. H. Trait: C. G. Hopkins: C. H. Hitcucock, 478. InDEX, 479. ee ae OF, see pees S. thee ae ive ays $ ~~ WHOLE NUMBER, OXOVIIT). - No. 283—JULY, 1 9 | Ge + : ‘& TAYLOR CO., PRINTERS, 123 TEMPLE STREE SHORE, PROCESSES AND ) SHORE a ‘DEVELOPMENT, me ae Major Doveras W. Jounson, N. ae Professor of - ‘Physiography, Columbia ‘University. eek a Contains the fullest discussion in the English language, of the behavior | _ waves and currents; the nature and origin of the deposits of ‘silt, sand and ~)- » «=. ‘gravel which are found along the shore and which affect all marine engineer- oat ing structures ; and the factors which affect harbors and harbor aro € Peet SF Iti is a timely refereiice book for engineers and a valuable ies Bee's? - . ers and students of Geology and Geography. OES ae {ae —xvii+584 pages. 6 by 9. 149 figures and 73 full- -page plates, Ctoti, b, $5. ) net. = ) oe = : Works of G. MONTAGUE BUTLER, E. MM. ey Dean, College of Mines and Engineering, University of Abinnay! ety se Pocket Handbook of Minerals. Second Edition. a e _» .- Designed for use in the field or class-room, > with little reference _ eer to chemical tests. ~~ . $F Tee ee 2 ix+311 pages. 4 by 63. 89 figures. Flexible “Fabrikoia” "binding, < ey pocket Hiawahowk of Biopipe Analysis. ayer 2) af With the proper instruments and this book, anyone, even “with © only a common-school education, should be able, in most canes, to. Ged i decide what each mineral contains. | 2 aaa tte i” r v+80 pages. 43 by 62. Cloth, 75 cents net. ee ete Geometrical Grystallopeaptiy: pa Pa ee Teaches the sight recognition of crystal forms and. systems, with the use of few, if any instruments. 3 ee viili+155 pages. 4 by 63. 107 figures. Cloth, $1. 30 net. 23 ieee om Crystallography, Minerals and Analysis, Complete. se ap ~ _A combination of the author’s three books in one volume. Sac See vii+546 pages. 4 by 63. 196 figures. Flexible “Fabrikoid” binding, ES $3. 50 net. 2 eee a Send for these books for FREE EXAMINATION. Also, ask for’ Special Subject Catalogue 13. aes ae JOHN WILEY & SONS, Inc. Rar “ se : Dept. B.—432 Fourth Avenue, New York a ne aS London: Chapman & Hall, ee ‘ened ; Montreal, Can.: : - Manila, PL: = = Renouf Publishing Co. ae NS Sa Philippine Raneatiie Co. . : aS Ge paseeTag is THRE AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES. ] ® Arr. I.—Present Tendencies wm Paleontology;* by we Eipwarp W. Berry. When a few days ago your president asked me to take part in the meeting to-night I felt bound to accede for friendship’s sake, rather than because of any message I had to deliver. On the eve of my departure from the country I have had no time to formulate and marshal what few ideas I have on the subject. Your president in his wisdom must have had a motive, otherwise why call in an Antony when Washington is full of Brutuses. Reec- ognizing as I do certain iconoclastic temperamental trends in myself, I suspect that he may expect that I will lay about me lustily in an endeavor to crack a few heads, and in the words of the poet ‘‘stir up the animals.’’ I am resolved, however, to overflow with the milk of human kindness, and to shed sweetness if not light upon the subject. One is embarrassed to decide whether to attempt the difficult role of historian of present tendencies where there is such grave danger of not seeing the forest because of the trees; to take the allotted time in criticism of past and present accomplishments in paleontology, or in an endeavor to sketch the things hoped for in the golden era of the future. The normal course of events age been so muddled by - world conditions during the past few years that it 1s diffi- cult, nay impossible, to discern with any clarity the present trend in paleontologic research. If I were asked to state the tendencies as they appeared to me prior to 1914, I could do no better than sketch certain trends that * Address read before the April meeting of the Geological Society of Washington. Am. Jour. Sct1.—Fourts Series, Vou. XLVIII, No. 283.—Juty, 1919. 1 2 Berry—Present Tendencies in Paleontology. were essentially nationalistic, although such generaliza- tions inevitably do great injustice to individual genius in all countries, and like all generalizations are only enter- taining half-truths. Paleontologic work in France, particularly in the verte- brate and plant fields, was characterized by breadth of view and philosophy of interpretation such as it has always exhibited and men like Douvillé and Kilian in the invertebrate field were fully sustaining the national tradi- tion. Perhaps nowhere have the problems of faunal facies and their lateral variations been as conclusively solved as in that country. German paleontology ran true to the racial temperament. The quantity of detailed descriptive work was probably greater than in any other country, the quality was not especially high and there was no correlation between facts and fancies. The scramble for self-advertisement and professorial advancement may be illustrated by Steinmann’s wild book on evolu- tions, or Jaekel’s speculations on the classification of trilobites, or Arldt’s book on paleogeography, or to go back to an earlier day by the factory for the manufacture of subjective phylogenies which Haeckel operated at Jena for so many years. Crossing the channel you will, I think, agree that British paleontology had the solid qualities characteristic of things British. Oftener than | not the work was absolutely solid. The point of view was still that of the founders. Whatever had been good enough for Sedgwick or Murchison should be conserved to the bitter end. The younger generation was busily engaged in trying to make over and patch the outworn garments of paleontology, not daring to suppose that what had been insoluble to the grand old men of British geology was capable of solution. (I quote substantially from a letter from an English friend.) One cannot probably get into a sufficiently detached frame of mind to visualize correctly the true position of the United States in the present status of paleontology. I think we undoubtedly exhibit a provincialism and radi- calism that goes with young nations as with young indi- viduals. Of one thing I feel reasonably sure, namely that the future belongs to us if we keep our ideals high enough. Our scientific, like our economic, opportunities, are very great. | A French paleontologist borrowing the metaphor from Berry—Present Tendencies in Paleontology. 3 the diurnal rotation of the earth writes me that the paleontologic sun is setting in Kurope while the dawn is just breaking in America. After making the proper deduction for the felicity of Gallic politeness there is a grain of truth in the figure. The two Americas stretching from the abundant Arctic lands to the north of our present continent, southward far into the southern zone, and with a very obvious former connection with Antarctica; possessing a fairly typical representation of all the great systems of rocks except for the weakness of our known Permian, Triassic and Jurassic history,—no region on the earth is as stra- tegically located for the solution of problems of earth history or the former distribution of life—both marine and terrestrial. We are, then, ‘‘called to a high calling’’ and have a mission to fulfill beside which the imperialistic dreams of reactionary political prophets are but as ships that pass in the night. In paleontology, as in all branches of human endeavor, there is nothing more obstructive of progress than a rev- erence for old ideas and systems which have outlived their usefulness. This is especially to be guarded against in an organization where rules and standards have to be formulated for the guidance of field parties and where there is an obvious necessity for laying down certain classifications for the presentation of results in reports and upon maps. There is a tendency, well illus- trated by the Geological Survey of the United Kingdom, for official sanction to lag about a generation behind the advance of knowledge. On the other hand there is the oreat danger that we in America, in a scientific isolation paralleling our former political isolation, filled with pride at the size of our country and the number of pages of geological contributions printed annually, may neglect not only the past but the present state of our science in other lands. I believe that a knowledge of the historic — development of paleontology and the details of the European succession is of the utmost importance, for Europe is after all historically the type continent despite the untypical development in a world sense of so many of its geological horizons. Undoubtedly the geological history of North America is much fuller and more normal than that of Europe, as 4 Berry—Present Tendencies in Paleontology. has been frequently pointed out, and if civilization had flowered first in the Western instead of the Eastern hemisphere, we should have to-day a much more logical geological column. But it was otherwise ordained, and ~ if, adopting the insular motto that North America is good enough for us, we make our scientific horizon coincide with our political horizon, we lose that breadth of view and perspective that is such a necessary part of our philosophy. We exchange for the vocational state of mind of a State University that intangible leaven indi- cated by the much abused word culture, which depends on point of view or perspective. The average Kuropean paleontologist has almost invariably a more cosmopolitan viewpoint than the average American paleontologist— an outcome of his training and the fact that the world is his field. It seems to me that proposals such as the elimination of the Permian as a system, or the lumping of the Triassic and Jurassic into a single system, are examples of our provincial point of view, entirely ignor- ing, as they do, the great development of marine series of these ages in other parts of the world. The inertia of old ideas and the vitality of traditions, even in radical minds, is astonishing. Witness the slow death of the notion, inherited from Brongniart, that the formation of secondary wood in stems, such as Sigillaria, stamped their possessors as exogenous seed-plants. Witness the implications, still alive and vigorous, that march in the train of the notion that an Age of Reptiles is a chronologic and geologic unit. Perhaps the most striking instance of what I am seeking to illustrate is furnished by the survival of Cuvier’s conceptions in stratigraphic paleontology. I doubt if there lives a paleontologist who would defend the theorem that faunas or floras were repeatedly exterminated by cataclysmic revolutions and renewed by special creations, and vet when you see the average paleontologist in action, his logic is inevitably colored by the assumption that a floral or faunal unit had an objective reality and is not merely a cross section of the tree of life at a particular time. Nothing it seems to me is more pernicious than the idea that, perhaps poorly determined, formational bound- aries are circuit breakers in the continuous life stream that has flowed down to us from the immeasurable past. This is especially illustrated in the discussions of the Berry—Present Tendences in Paleontology. D more important boundaries. Where a well-marked time- interval intervenes between two normal marine units exposed to our investigation, it is easy sailing, but when the hiatus is small or is partially bridged by marine formations elsewhere, or by preserved continental sedi- ments—disputation is endless. I need only cite in sup- port of this contention the Hercynian, Rhaetic, Wealden and Laramie questions. When terrestrial sediments and life replace marine sediments and life in a single section or vice versa we insist that the particular marine fauna vanished or appeared with the particular retreat or advance of the sea in that region and that the terrestrial fauna and flora appeared or vanished with the deposits in which it is found. That the terrestrial and marine organisms were contemporaneous over a much longer interval than is represented by the particular associated deposits is apparently never considered. This might be illustrated by a discussion of the age of some of our Cre- taceous formations, but I pass on to the broader question, often lost to view, that our systematic units in so far as their contained floras. and faunas are concerned are purely subjective academic pigeon-holes and if we had the whole record we probably could not differentiate Silurian from Devonian, Jurassic from Cretaceous or Oligocene from Miocene. We have hoped for much from the so-called method of diastrophism, and it has undoubtedly immeasurably widened our stratigraphic horizon and rationalized many outstanding problems. As an absolute criterion for the determination of larger units or as affording the basis for the rhythmic time- table, it was foreordained to failure. J can see no more reason for assuming that two successive cycles of sedi- mentation correspond in relative duration, than there would be for assuming that because a man, a turtle and an elephant are born, live and die, that all endure for the same number of years. Any succession of changes is in a sense rhythmic, but the elaboration depends on the location of a particular section with respect to the direc- tion and distance of the basin from which the trangres- sion emanated. We would make a sorry mess of it did the segregation of Permian, Triassic or Jurassic rocks depend on their visible development in North America. The mid-Tertiary section in the northern Paris basin represents nearly continuous sedimentation while farther 6 Berry—Present Tendencies in Paleontology. south there are many breaks. Neither section could be correctly interpreted in the absence of the other. Progress in paleontology can only result from the . action and reaction of the two parallel lines of human endeavor, namely, the accumulation of facts through exploration, research and discovery, and the elucidation of the accumulated facts through advances in philosophic interpretation. The temple of science remains merely a pile of bricks and stone until each brick and stone is fitted into its proper niche. These two lines of endeavor rarely develop proportionately. The accumulation of fact usually far outruns their adequate interpretation, for example, paleontology made rapid progress in the early years of the 19th century through the discoveries of Cuvier 1769-1832 and because of his genius as a com- parative anatomist. It was checked by his conspicuous failure as a natural philosopher, exemplified in the invertebrate field by d’Orbigny’s (1802-57) 27 distinet creations. His successor Owen (1804-1892) was simi- arly endowed with gifts of descriptive industry and was a still greater failure as a philosopher. The slowing of the wheels of progress by false philosophy is well illus- trated by the historic influence of the dogmatic doetrines of the so-called Neptunists emanating from Werner and his students (1750-1817). One might mention many similar instances nearer our own day if more were nec- essary. It would be a fine thing if paleontologists could imitate the practice of business concerns in periodically taking an inventory and making up a balance sheet, writing off the moribund theories and discarding obsolete methods, and determining if there was sufficient gold in the treas- ury as a reserve for the paper in circulation. For years, invertebrate, vertebrate and plant paleontologists have seemingly been largely actuated by a desire to merely multiply the diversity of the organic record. Zittel was the first to bring into prominence the truism that fossils are not primarily ‘‘things dug’’ and to be studied like minerals, but as belonging to the dynamic world of once living things—a part of a biota and something multifa- riously interacting with the particular organic and physical environment. Vertebrate paleontology has probably been foremost in stressing the biologic aspect of the subject, while the others and particularly the plant Berry—Present Tendencies mm Paleontology. v6 side have lagged behind. Stratigraphic paleontology eannot, however, be divorced from biological paleontol- ogy without becoming sterile. Historical geology which is the ideal we strive for is a vast synthesis woven of many diverse strands—the warp is stratigraphy but the vari-colored woof is furnished by a multitude of criteria and we cannot ignore a single leaf lobe or venation pattern or tooth cusp or bone facet or loop pattern or hinge plate without a knot or break in the fabric. Fossils are not to be looked upon merely as medals of creation to be transmitted to the paleontologist for report, resulting usually in a hasty and ill considered list of ‘‘sp’’-’s, ‘‘ef’’-’s and question marks, to be used as padding for some printed report. Neither is there room in our science for the closet naturalist who cannot see a contract nor tell the bottom from the top of a section in the field. Paleontology is equally crippled whether divorced from biology or stratigraphy. Bird’s-eye methods that cannot discriminate between mid-Cretaceous and mid-Tertiary Foraminifera are of no service to geology. Loosely drawn genera and spe- cies are no longer useful. Witness the transformation of the genus Olenellus into the wonderful family Mesona- . cide in the skillful hands of a Walcott. The precise systematic methods introduced by Waagen (1869) and so largely exemplified in the work of Ulrich and David White, which seek the recognition of the most minute mutations—often somewhat contemptuously referred to as the splitting of hairs—is the only method by which paleontology can contribute to stratigraphy. In paleo- botany the older bird’s-eye obscurantist method has no living champions and the time is not far distant when all loose generic aggregates like Spirifer and Venus or Zamites will join the limbo where now dwell Ammonites, Goniatites and Ceratites, and only emerge as useful descriptive terms purged of generic significance. The same is true of broadly conceived specific aggregates. The poorer the diagnosis and illustration of a species at the hands of the paleontologist, the greater the variety of diverse things that come to be called by the same name, and I could give you many illustrations proving that the more common names in lists drawn up from dif- ferent regions, particularly if they are the work of the earlier workers, are absolutely worthless. This is espe- 8 Berry—Present Tendencies in Paleontology. cially true of the work of Ettingshausen, Geinitz, Lesquereux, and their contemporaries in Carboniferous paleobotany. Even where identity seems assured as in dealing with cortical remains of forms like Sigillaria and Lepidodendron, assumed cosmopolitanism is vitiated by. the discovery that identical surface form between speci- mens from Kurope and America was accompanied by slight differences in anatomy or specific differences in cone structure. From Moses’ account of the spread of the passengers of Noah’s ark to Matthew’s recently published Climate and Evolution, many attempts have been made to explain the origin and migration of organisms.- It has taken a long time for naturalists to realize that modern distri- bution has its key in ancestral distribution, or to dis- ceriminate the fluctuation of life zones from such very different seasonal phenomena as are displayed by the migratory birds. It would perhaps be better to elimi- nate the word migration altogether and use the term dis- persal, since the criteria of voluntary and involuntary action are of extremely doubtful validity. The time of origin of an organic type or assemblage, the place of origin, the area once occupied and the time of extinction or the area now occupied, are among the most important questions with which we have to deal. Obviously without the correct chronology such questions are insoluble, hence the importance of far flung correla- tions and the need for the most critical criteria for correlation. Similar successions of fossil-bearing sediments in dif- ferent areas naturally resulted in this correspondence being considered indicative of synchroneity. Huxley in his anniversary address to the Geological Society of London in 1862 was the first serious critic of this concep- tion. He, as you know, proposed the term homotaxis for the alternative idea due to the necessity of taking into account the time consumed in the dispersal of organisms. Those who adopt the latter and apparently reasonable assumption sometimes take the position (E. Forbes, N. 8S. Shaler) that similarity of organic content, instead of being indieative of chronologic synchroneity, proves that the compared deposits could not have been contempora- neous. Conceding that this view grossly exaggerates the importance of the time element, it is to be noted that of Berry—Present Tendencies in Paleontology. 9 late there has been a tendency to deny altogether the validity of the homotactic viewpoint. The question is vital in a consideration of past evolu- tion, distribution, climatic conditions and paleogeog- raphy. Itis also almost infinitely complex, and there are various underlying conceptions such as the rate of spread of different classes of organisms and the degree of cos- mopolitanism reached by marine organisms during times of land emergence and of terrestrial organisms during times of submergence when the obverse records are largely wanting, that have a very important bearing. If the conditions, both geographic and topographic, which are predicted for the various Appalachian troughs or basins during Paleozoic time, are correctly interpreted, as there seems to be no reason for doubting, we are intro- duced to an environment which is special in the sense that it is not duplicated at the present time anywhere on the earth’s surface so far as I can see. This being true the generalizations derived from the study of the over- laps and the rapid floodings of these Appalachian basins must be applied with great caution to other sets of con- ditions such as determined the broad seas of Jurassic, Upper Cretaceous or Kogene times. If our present Coastal Plain margin were to take another dip beneath the ocean, would it be possible for the paleontologist of a million years hence to establish the synchroneity of deposits formed at the same time along our middle Atlantic and Gulf coasts or to differen- tiate these chronologically from such late Pleistocene shell marls as those at Wailes Bluff at the mouth of the Potomac or Simmons Bluff in South Carolina? I think it would be feasible, and am inclined to disagree with the universality of the statement (Ulrich) that for strati- graphic purposes the coarseness of the distinguishable chronologic units obviates the necessity of attempting to deal with the theoretically true time involved in dispersal. This may be perfectly true, however, of some of the Paleo- zoic transgressions over the base-levelled Appalachian troughs and also when dealing with marginal invasions around the borders of a single oceanic basin where the faunas have had time to become generally distributed. Our conclusions usually do not rest upon irrefutable logic, however, and it is most important to determine by closer analysis the interlacing waves and ripples of dis- 10 Berry—Present Tendencies in Paleontology. persal of animals and plants that have been going on since the beginning of life—as well as the rapidity of radiation of different types of organisms. Paleogeog- raphy will be on a far less speculative footing when it rests on proof and not on authority. | I do not believe that we can safely generalize with our present stock of accumulated knowledge. Take a theo- retical case of a transgression and assume that the rate of change of level amounted to a foot a century, which I suppose would be considered fairly rapid, and that the submergence amounted to 500 feet, the time involved would be 50,000 years. The Upper Cretaceous trans- gression represented by the Dakota sandstone and Ben- ton involved perhaps twice as great a change of level, and disregarding any halts or oscillations of the strand it would still mean that 100,000 years were involved in the operation. Inevitably there would be changes in salinity © and climate which must be reflected in the faunas. It seems to me that we must either admit a certain measure of validity of homotaxis in all except special cases or assume that the breaks between faunally distinct forma- tions represent very great lapses of time. On the other hand changes in faunal facies in passing from a forma- tion like the Onondaga to the Hamilton mean merely a change in local environment such as is, I imagine, respon- sible for most examples of recurrent faunas, so-called. The question is also influenced by what the term fauna denotes. Does it mean the whole biota or only certain forms considered as typical. Certainly I should expect Belemnitella to spread more rapidly than the contem- poraneous Exogyra, or an Eichinoid more rapidly than a Pentremite. The varying vitality or organisms under adverse conditions, either as mature animals or in the larval state, is also a factor of great importance. Larval oysters are very intolerant under adversity while other sedentary molluses have a much more hardy progeny. Another factor in distribution is the relative length of the free swimming larval stage in sedentary forms. There are wide limits of usage as to what characterizes a fauna and what are its critical members. Shall we rely on its more abundant dominant species, on the percentage of species common to another fauna of known age, to the first or the last appearance of certain forms, or shall we place the greatest weight upon the rarer short lived Berry—Present Tendencies in Paleontology. 11 types? It seems to me that no single rule of general application can be laid down. There should be no dogmatism! In general the broadly conceived species which are abundant, are long ranging and of less value than the perhaps rarer more restricted types. One type of organism may be much more valuable than another. I should regard the active Zeugledon of the open sea as a much more critical indication of Upper Kocene age than a dozen species of Mollusca. Similarly I should regard the sea lizards of the Upper Cretaceous or fishes like Pyenodus as of much more diagnostic value than species of HKxogyra or Inoceramus. The wider removed the areas to be correlated, the more important are the geo- graphically wide ranging and geologically restricted forms and the greater the importance to be attached to their initial appearance. | Progress depends on research, as even an outcrop chaser in Oklahoma would probably admit, but research is about as much abused a term as culture. Research to the neophyte at the university, particularly in current biologic and psychologic investigation, consists in ‘‘hav- ing a problem’’ and I often wish that the Board of Health classed ‘‘having a problem’’ along with other communicable diseases and would quarantine its victims. True research does not depend on subject matter but on method and the invidious distinction and discussions of pure and applied science would have no point were it not for the pragmatic individuals, false and mercenary ideals and superficial Burbank methods that characterize so much of applied science. I should wish to depreciate the tendency, rampant throughout the world, and accelerated by war conditions, to seek a justification for research as a means toward some economic end. If the elucidation of earth history and the origin and evolution of life on the globe are not of prime importanee as ends in themselves; if the whence and the why and the whither are not supreme, then indeed has our lot fallen among evil days. Research is, I suspect, a dangerous subject for discus- sion before a body of men the majority of whom are con- nected with a great Federal Bureau. There are so many very necessary and commendable public services crying for accomplishment, and there is so much justification for the pious wish to give the people what they think they 12 Berry—Present Tendencies in Paleontology. want, that it is not to be expected that the pragmatist and the idealist will contentedly lie down together like the proverbial lion and lamb, or that the Survey will ever lack for eritics or defenders. Without posing as either may I not venture to hope that research will constantly increase in both quality and amount, and that the day will speedily arrive when a first rate paleontologist can com- mand as large an income in the successful practice of his profession as he can in an administrative position. I have, I fully realize, inflicted upon you to-night a few rather poorly articulated and in some eases trite illustra- tions. A large subject hastily presented always leads to half truths, unless elaborated in much greater detail, and I can only hope that those who follow me in the series will display a greater competence than I have done. Johns Hopkins University, Baltimore, Maryland. Sellards—Comanchean Formation. 13 Arr. II1.—Comanchean Formations underlying Florida; by E. H. Setiarps. During the latter part of 1917 the Florida Geological Survey received through the courtesy of Mr. H. B. Good- rich, a very important set of well samples from a deep well then recently completed by the Dundee Petroleum Company in Sumter County, Florida. Early in 1918 a few of the samples from this well, in which foraminifera were abundant, were forwarded by the writer to Dr. T. W. Vaughan of the United States Geological Survey by whom they were referred to Dr. Joseph A. Cushman. The foraminifera of these samples indicated, according to Dr. Cushman, the presence of Comanchean formations in this well. Subsequently Dr. Cushman undertook for the State Survey a study of the cuttings from some fif- teen wells in Florida, and has now published the results of his study.t. The location of the wells from which samples were obtained is indicated on the accompanying sketch map (fig. 1). In nine of the wells Comanchean fossils were recog- nized. These are numbers 2, 3, 4, 5, 7, 8, 11, and 15 as shown on the map. Numbers 6, 9, and 10, in which Comanchean fossils were not found, are shallow wells, from 113 to 190 feet in depth, terminating in the Hocene formations. Well number 12, at the north side of Lake Okeechobee, was represented by samples to the depth of only 500 feet; number 13, at Boca Grande, is represented by but one sample in which no characteristic fossils were found; number 14, at Ft. Myers, from which no Coman- chean fossils were obtained, is represented by a series of samples submitted by the driller as representing the for- mations to the depth of 950 feet. Hxamining the results -as a whole it is seen that fossils of the Comanchean for- mations were recognized in all wells of considerable depth from near Tallahassee in West Florida to Cocoa and Tiger Bay somewhat south of the center of peninsular Florida. In southern Florida these formations, although present as indicated by the well on the Florida Keys (well No. 15), lie at a much greater depth than in Centra Florida. Owing to the relatively small number of samples * Fla. Geol. Survey, 12th Ann. Rpt., 1919. 14 Sellards—Comanchean Formation. obtained from some of the wells, together with the often imperfect preservation of the fossils, the minimum depth to the top surface of the Comanchean formations is fre- Fie. 1. Sketch map indicating location of wells. quently difficult to determine. Nevertheless, approxi- mate results are obtained by indicating the depth at which fossils of these formations are first recognized. In the Sellards—Comanchean F' ormation. 15 well near Tallahassee (well No. 2) Comanchean fossils are recognized at the depth of 325 feet, although the for- mation may extend much nearer the surface. The eleva- tion at this well is 20 or 25 feet above sea-level. At Jacksonville, well No. 3, Comanchean fossils appear at 820 feet. Here again the formation may extend to a higher level, although not above the 550-foot level as samples from that depth contain Kocene fossils. The ele- vation at this well is 10 or 15 feet above sea-level. In wells number 4 to 11, located in central peninsular Flor- ida, the Comanchean, when recognized, is found coming to a much higher actual level than at Jacksonville. At Anthony in Marion County, the Comanchean is recog- nized in the 110-foot sample (well No. 5). The ground level at this well as indicated by the topographic map is about 80 feet above sea. Hence, the Comanchean here comes to within about 30 feet of present sea-level. At Apopka, well No. 8, Comanchean fossils were found in the 115-foot sample. According to levels obtained from the Atlantic Coast Line Railway, the depot at Apopka is 125 feet above sea, and the well is said by Mr. Hull who preserved the sample, to be about 8 or 10 feet above the depot. From this approximate data it appears that the Comanchean at this place rises somewhat above sea-level. The samples from two wells at this place contain phos- phate pebbles to the depth of about 220 feet. Since the Comanchean is not observed to contain phosphate pebbles in any of the other wells it seems probable that the phos- phate pebbles had fallen from a higher level and that the samples are thus mixed in both of the wells to about that depth, notwithstandng that casing was placed in one of the wells at 117 feet and in the other at 127 feet. If the mixing of samples is due merely to material falling in from above, the observations as to the level of the Coman- chean formations are not thereby affected. Farther to the south, at Tiger Bay (well No. 11), the Comanchean is first recognized at 550 feet, the surface elevation at the well being probably between 125 and 150 feet above sea. On the Atlantic Coast, at St. Augustine (well No. 4), the Comanchean is recognized at the depth of 440 feet and may extend somewhat nearer the surface. It is thus seen that in central peninsular Florida the Comanchean for- mations, as identified on the basis of these fossils, rise almost to present sea-level, possibly above in places. 16 Sellards—Comanchean Formation. From this central area they dip slowly to the east, lying ~ at only a moderate depth on the Atlantic Coast at St. Augustine. To the northeast they dip more rapidly as indicated by the well at Jacksonville, while to the south from the central part of the peninsular they likewise dip very appreciably. In a paper published in the Twelfth antes Report of the Florida Survey the writer has sought to use the Kocene formations as an index to structural conditions in peninsular Florida. In this paper the data on the Eocene obtained by Cushman in connection with his study of the well samples is supplemented by data from a number of other wells of which records and samples have been obtained from time to time. From these data it is shown that there is a large belt extending entirely across north Central Peninsular Florida in which the Kocene forma- tions lie either above sea-level (west side of the penin- sula) or at from 100 to 200 feet below sea-level (east side of the peninsula). 'T'’o the north the Kocene forma- tions apparently dip very shghtly; while to the east the dip is somewhat greater. To the northeast as indicated by the wells at Jacksonville the dip is pronounced. Like- wise in passing to the south and southeast from north- central peninsular Florida the dip in the formations is quite appreciable. As early in 1881, Dr. EK. A. Smith indicated in a paper and sketch map published in this Journal, that approximately the western half of the Flor- idian land mass is submerged to a shallow depth below sea-level.2 This conclusion has been supported by subse- quent studies and in addition there has been gradually developed the knowledge of a more complicated structure involving recognition of a broad dome centered toward the west side of the north central part of the peninsula. The anticlinal structure of the Floridian peninsula as a whole has likewise been long recognized, and the structure here referred to may possibly be characterized as a slight doming in the larger structure. The abruptly terminat- ing margins of the Florida land mass, at or near the 100- fathom line in the Atlantic Ocean and in the Gulf of Mexico, suggest faulting along these lines by which the land mass has been lifted as a block as well as folded as a large geo-anticline. *Vol. 21, pp. 292-309. 1881. University of Texas, Austin, Texas. Holm—Studies in the Cyperaceae. Av Arr. Il].—Studies m the Cyperacee; by Tuo. Houm. XXVII. Notes on Carex podocarpa R. Br., C. Monta- nensis Bail., C. venustula Holm, C. Lemmoni W. Boott, and C. equa Clarke. (With 12 figures drawn from nature by the author.) Carex podocarpa R. Br. When. Robert Brown was engaged in identifying Dr. Richardson’s arctic plants, a specimen of the genus Carex attracted his attention on account of the nut being stipitate; upon this specimen, which was rather imma- ture, he established the species C. podocarpa. At that time the structure of the nut in Carex was but very imperfectly known, since most authors confined them- selves to describing the structure of the perigynium (utriculus) alone. Otherwise the specimen showed no character of particular interest, and the diagnosis pre- sented by Robert Brown is very brief. By Boott the - specimen became illustrated in Hooker’s Flora Boreali- Americana (vol. 2, tab. 224), and this figure together with the diagnosis does enable us to get some idea of the plant, of the species it was intended for. And although being a small, rather inconspicuous plant, C. podocarpa has nevertheless been accepted, and not infrequently so, as identical with such stately species as C. macrocheta C. A. Mey, and C. spectabilis Dew. The fact that very recently? the species has been rede- scribed and attributed such characters as the original plant never possessed, may render the following supple- mental note acceptable. Naturally the name of the author, who proposed the species, has carried great weight, and now for nearly a century the species has been faithfully accepted, figuring prominently in lists of plants _ from the boreal regions of North America and Hastern Asia. No author, so far, has ever suspected that C. podocarpa was described and named—but of course with a different name—before Robert Brown proposed it as a new species. However, the material brought together of what has been supposed to be C. podocarpa has proved +Macoun, John: Catalogue of Canadian plants, Part IV, p. 149, Mon- treal, 1888. * Kiikenthal Georg: Cyperacee—Caricoidee in A. Engler ‘‘ Das Pflanzen- reich, Leipzig, 1909. Am. Jour. Sct.—FourtH SERIES, Vou. XLVIII, No. 283.—Jury, 1919. 2 18 Holm—Studies m the Cyperaceae. very unlike the species so named, and, indeed, by no means conspecific; moreover the recently published diag- nosis by Kiikenthal (l. c.) deviates in several respects from the original as well as from the figure, cited above. The original diagnosis of Carex podocarpa® reads: ‘‘spica mascula solitaria, femineis binis pendulis oblongis, stigmatibus tribus, fructibus ellipticis brevissime rostel- latis integris levibus acheniisque pedicellatis, foliis cauli- nis inferioribus brevioribus lanceolatis. Brown M. 8.”’ The species is described together with C. capillaris and C. limosa in a separate section: ‘‘spicis sexu distinctis, mascula solitaria, femineis omnibus pedunculatis.’’ According to our friend, the late Mr. C. B. Clarke at Kew (in litteris April 16, 1902), the figure by Boott (J. c.) is accurately drawn, and shows the specimen collected by Richardson n. 370, upon which Robert Brown founded the species. The species is phyllopodic and stolonif- erous; the nut is stipitate. But in accordance with Kiikenthal (J. c. p. 410) C. podocarpa is aphyllopodic “Scite aphyllopode,’’ and his description calls for a larger plant with two to three pistillate spikes, the basal remote, born on a long, very slender peduncle. No men- tion is made of Boott’s figure, and among the specimens examined, reference is made to Richardson’ s plant (n. 370), and, furthermore, some specimens collected by J. Macoun in Alberta: Sheep Mt., Watertown Lake (n. OT oh ye These specimens from Alberta average from thirty-five to forty-five em. in height; the number of pistillate spikes is from three to six, but mostly three; the nut is stipitate. But characteristic of these specimens is the dimorphic structure of the shoots, some being purely vegetative, others purely floral, the latter bearing leaf-sheaths with very short blades. They illustrate, in other words, the structure by Elias Fries defined as ‘‘aphyllopodic.’’ We have previously called attention to this peculiar structure of shoots noticeable in several species of Carex,’ but since the structure has been misunderstood or not con- sidered of sufficient importance as a morphological character, judging from a number of instances in the *Plants from the Appendix to Captain Franklin’s narrative. London, 1823. (The miscellaneous botanical works of Robert Brown, vol. 2, p. 517, London, 1867.) *Holm, Theo: Segregates of Carex Tolmiei Boott. (This Journal, vol. 14, p. 418, December, 1902.) | . Holm—Studies in the Cyperaceae. 19 monograph presented by Kiukenthal, it may be appro- priate to insert some quotations from the paper of Elias Fries.» Having described briefly the cespitose and sto- loniferous types of growth Fries also points out the difference in foliage at the base of the flowerbearing stem or culm, viz.: ‘‘ Alia memorabilis differentia posita est in culmi pede; hic vel cingitur vaginis aphyllis (Aphyllo- pode) vel vaginis omnibus foliiferis imis licet emarcidis (Phyllopode). Quanti momenti hee differentia est, col- latis C. stricta et C. acuta, C. cespitosa et C. vulgari, facile videbis.’’—Aphyllopodic are for instance C. mar- tuma, C. Lyngbye, C. cryptocarpa, C. stricta, C. cespr- tosa, ete., while the following are phyllopodie: C. prolixa, C. acuta, C. rigida, ete. It deserves notice that besides the species with monopodial ramification (C. laxiflora cet.), which are all ‘‘aphyllopodic,’’ not a few species of those with sympodia belong to this same category (C. Tolmet, C. angustata, C. spectabilis cet.). Such phyllo- and aphyllo-podic species are readily to be distinguished from each other, inasmuch as the character is constant; low forms of the aphyllopodic C. macrocheta exhibit in this wise an entirely different aspect from the phyllo- podie C. ustulata, with which such dwarfish forms have often been confounded. And no instance has, so far, been observed where an aphyllopodic species might change its habit so as to become a phyllopodic variety, or vice versa. In other words the phyllopodic C. podocarpa R. Br. as depicted by Boott cannot positively be conspecific with the plant collected by Macoun, which is aphyllopodice. The stipitate nut is not a character possessed by C. podo- carpa alone, but recurs in several species of the Aeora- stachye, when examined at young stages, furthermore in some of the Melananthe (fig. 5). Finally there is another plant which has also been referred to C. podo- carpa by Kiikenthal (J. c.), and this plant was collected on the northwest coast of this continent by Seemann (n. 2207); it is a phyllopodic species, and by C. B. Clarke identified as C. ustulata Wahlenb. Several years ago when engaged in identifying some large collections of Carex mainly from Alaska, sand British Columbia, we were unable to find any specimen that might represent the true C. podocarpa R. Br., > Fries, Elias: Synopsis Caricwm distigmaticarum, spicis sexu distinctis, in Seandinavia lectarum. (Bot. Notiser, p. 97, Lund, 1843.) 20 Holm—Studies im the Cyperaceae. although there were some, which were identical with specimens named so by other authors. However, to make certain about this matter we asked C. B. Clarke at Kew for assistance, and it is through his kindness that we are able to offer the following, valuable information, written in a letter dated April 16th, 1902: ‘‘I find that Richardson n. 370 is a single culm (the utricles. very young), and Boott has noted on it that it is the whole material for the species. And Arthur Bennett has named this type- piece C. rariflora Smith: and so it is! Richardson eol- lected a quantity of C. rariflora and this ‘ podocarpa’ looks certainly a fragment out of the rest of his rariflora, which was sent up to Brown (at the British Museum) to draw up his hstupon. ‘The Kew Index and other authors cite C. rarvflora Smith Engl. Bot. v. 4 (1828) p. 100; and if this were the true original citation, the name podocarpa would have priority—but I find C. rariflora Smith (in Sowerby) Engl. Bot. v. 35 (1813) t. 2516 and there may very possibly be names anterior to this.’’ In comparing Boott’s figure (lJ. c.) with a young specimen of C. rari- flora Sm. there can be no doubt about the correctness of the identification proposed by the botanists at Kew. But if we compare the diagnosis of C. podocarpa submitted by Kiikenthal (1. c.), and founded upon three plants of very distinct habit and by no means conspecific, the result is, of course, confusion. For even if Robert Brown’s C. podocarpa had not been described before, it could never be understood as representing an aphyllopodic species, as claimed by Kiikenthal, and confounded with the plant collected by Macoun (I. c.). Carex Montanensis Bail.® This is the name of the species collected by Macoun (1. c.). It is a member of the Melananthe Drej., and very characteristic by the several, two to six, long-pedun- culate, drooping, dark-colored pistillate spikes, and by the relatively tall, aphyllopodic culm; the latter char- acter is not, however, mentioned in the diagnosis; fur- thermore may be stated that the scales of the staminate spike are light reddish-brown with green, not excurrent midrib, while those of the pistillate are deep-purple to black with no midvein visible; utriculus is purplish- spotted, with the beak almost entire, spinulose, and with ® Bot. Gazette, p. 152, May, 1892. Holm—Studies in the Cyperaceae. 21 two very distinct marginal nerves; the nut is triangular, much smaller. than the utricle, and stipitate; there are three stigmata. The specific name is unfortunate, as are geographical, specific names in general; the species, originally estab- lished upon a plant from Montana, has since been col- lected in Idaho, in Alberta, British Columbia, and Yukon. Carex venustula Holm* (figs. 1-5). This species is a near ally of the preceding, but is readily distinguished by the long leaves of the vegetative shoots, and by the pistillate scales being obtuse to aris- tate, much shorter than the perigynium, which is minutely granular above. , By Kukenthal (/. c. p. 412) these two species are con- sidered identical with C. spectabilis Dew., together with the phyllopodie C. microcheta Holm; beside that a part of the specimens of the former (C. Montanensis) has been referred to C. podocarpa. The section ‘‘Scite’’ Kikenth. seems untenable, since it is characterized as containing only aphyllopodic species; but among the species referred to this section we find the following phyllopodic: C. podocarpa R. Br., C. mcrocheta Holm, C. nesophila Holm, and C. littoralis Schweinitz. By eliminating Carex podocarpa R. Br., so far entirely misunderstood, the identification of several northwestern Carices becomes facilitated, and to no small extent. Carex macrocheta C. A. Meg. at its various stages, and especially the younger ones, cannot possibly be con- founded with C. ustulata Wahlenb., a phyllopodic species ; and Carex spectabilis Dew. with the scales merely mucro- nate, of a lighter color, is sufficiently distinct from C. ustulata Wahlenb. as well as from C. macrocheta C. A. Mey. These three species are actually those that have hitherto been confounded with the troublesome C. podo- carpa RB. Br. With respect to C. Montanensis Bail., and C. venustula Holm, both aphyllopodic, these cannot be considered conspecific with the phyllopodie C. micro- cheta Holm; neither can the phyllopodic C. nesophila Holm be looked upon as representing a variety (sub- rigida Kikenth.) of the aphyllopodie C. macrocheta C. A. Mey. *Holm, Theo: New or little known species of Carex. (This Journal, vol. 17, p. 304, April, 1904.) 29 Holm—Studies in the Cyperaceae. Carex Lemmom, W. Boott (figs. 9-12). Although an excellent, in several respects quite remarkable species, and well described by the author William Boott,s Carex Lemmoni has for the last thirty years been identified and distributed under another name: C. ablata Bail. The error was detected by C. B. Clarke (in litteris), who then wrote a diagnosis, and gave a name to the so-called C. Lemmon: Carex equa; m accordance with Clarke, C. equa is the plant which by W. Boott was enumerated as C. fulva var. Hornschuchiana in 8S. Watson’s Botany of California (vol. 2, pp. 228, 250), and also the plant called C. Lemmoni by L. H. Bailey in his Preliminary Synopsis of North American Carices.® By Kukenthal (1. c. p. 666), C. Lemmoni (non W. Boott) and C. serratodens (non W. Boott) are considered iden- tical, and the name serratodens is given the preference; nevertheless among the specimens cited by Kukenthal is Bolander’s (n. 4995), which is C. albida Bail., a near ally of the true C. Lemmonz1, beside C. F. Baker’s (n. 811), which is C. equa Clarke. It is hardly necessary to state that the diagnosis does not cover either C. serratodens W. Boott nor C. albida Bail. And by this same author (1. c. p. 558) C. ablata Bail. has been made a variety of C. luzulefolia W. Boott with forma albida (Bail.) Kuken- thal (C. albida Bail.). In other words W. Boott should have proposed three species of Carex: luzulefolia, serra- todens and Lemmont, constituting an assemblage of such confusion!—However the fault depends only upon the fact that recent authors have not consulted the literature, or they have not interpreted Boott’s diagnoses in the proper way. It is really difficult to understand how Boott’s C. Lemmom could ever be misunderstood, and for so long a time, although a considerable material became collected from a number of stations, especially along the Pacific coast from Southern California (fide S. B. Parish) to British Columbia, in view of the fact that it was described very minutely; while the establishment of the species ablata Bail. merely rests on some incom- plete, brief remarks :1° “‘C. frigida of American botanists, not Allioni. Distiguished from C. frigida chiefly as fol- lows: Culm stiffer and more erect: leaves broader and firmer, usually shining, commonly shorter: staminate *Boott, William: Notes on Cyperacee (Bot. Gaz. vol. 9, p. 85, 1884). ° Proceed. Am. Acad., p. 112, 1886. 10 Bailey,:1a He Notes on Carex IX. (Bot. Gaz. vol. 13, 1888). Holm—Studies in the Cyperaceae. 23 spike smaller, nearly sessile: pistillate spikes shorter and thinner, lighter colored, shorter stalked, the upper 2 or 3 usually aggregated and sessile or very nearly so: scales obtuse, usually shorter: perigynium not so long and slender-beaked. Western Territory.’’—No mention is made of the probable affinity with Boott’s C. luzulefolia, or of the possible identity with his C. Lemmon. This seems the more curious when this same author (L. H. Bailey) in the following year proposes his C. albida as an ally of C. luzulina Olney," with no reference to C. luzule- folia Boott or to C. ablata Bail., not speaking of the true C. Lemmom W. Boott. Having had access to a number of specimens identi- fied by Professor Bailey himself as representing C. ablata we naturally depended on the correctness of the determi- nation. But some years ago, when called upon to name some Californian Carices, we came across the so-called C. Lemmom, and being unable to identify this by means of comparing the original diagnosis, we submitted the specimens to C. B. Clarke. Again it is through the kind- ness of this excellent botanist that the difficulty became removed, and we were informed that Boott’s C. Lemmon had been sent to Kew as C. ablata Bail., while the _ so-called C. Lemmonit was an undescribed species for which Clarke proposed the name equa; it was based upon material collected by C. F. Baker in California: San Mateo (n. 811). To prevent future difficulty regarding the identification of C. Lemmon W. Boott we might reprint the original diagnosis: ‘‘Cespitosa. Culmis 2 ped. altis, latere 14 lin. latis, obtusangulis levibus, vaginis omnibus foliiferis, infra medium foliatis. Foliis lineari-lanceolatis, apice subulato triquetris, erectis, vaginatis, 114 lin. latis, cul- meis 3-4, sterilibus 6-10 poll. longis. Bracteis foliatis vaginatis, spiculis longioribus, culmis’ brevioribus. Vaginis 14-114 poll. longis. Ligula oppositifolia obtusa. Squamis pallide-ferrugineis, membranaceis, margine hya- lino, oblongo-obovatis, obtusis, mucronatis, perigynia equantibus. Perigyniis ferrugineis, membranaceis. levi- bus, triaquetro-oblongis, basi acutis, acuminato-rostratis, 13/ lin. longis. 14-34 lin. latis, rostro bidentato margine serrato dentato. nervatis. Achenium atro-castaneum, triquetro obovoideum, basi productum apice obtusum ™ Mem. of Torrey Bot. Club, vol. 1, No. 1, 1889. 24 Holm—Studies in the Cyperaceae. stylo equali apiculatum. Stigm. 3. I. G. Lemmon 1875.’? Some few remarks may be added to this diagnosis, viz: The culm is phyllopodic, and the number of spikes, the pistillate, quite variable; there is only one sessile stami- nate spike, and with respect to the pistillate the upper- most two or three are situated close to the base of the terminal, the staminate, while the lower ones are remote; the number of pistillate spikes averages from two to six, five being the most frequent.‘? Furthermore the scales of the pistillate spikes (fig. 10-11) are mostly obtuse, and fringed along the upper margin, but in some specimens the midrib was extended so as to make the scale mucro- nate; however such mucronate scales were observed in spikes of which some of the other scales were simply obtuse. In none of the mature specimens examined did we observe any case where the scales were of the same length as the perigynia; they were constantly shorter than these (fig. 11). The perigynium (fig. 12) is gener- ally very narrow, and spinulose along the margins from the middle of the body to the apex of the beak. Finally in most of the specimens from Mount Paddo, Washington, kindly presented to the writer by Mr. W. N. Suksdorf, the basal leaves were shorter and more spreading, rather than erect, the bracts subtending the spikes were shorter and narrower, and the color of the scales much darker than in typical specimens. Lindman, C. A. M., Zur Morphologie und Biologie einiger Blatter und belaubter Sprosse, Bihang Svenska Vet. Akad. Handl., 25, Afd. III, No. 4, 63 pp., 20 text figs., 1899. Arber—Atavism and Law Irreversibility. 29 habitual orientation, not however by losing their usual twist, but always by adding a second torsion above the first. This shows, as Lindman points out, how inveter- ate (eingewurzelt) this habit has become; in other words it demonstrates that when the plant can reach the same goal either by retracing its steps, or by pursuing its adopted path to a further point, it has an overwhelming bias towards the latter course. Dollo’s Law has been subjected to considerable eriti- cism, especially by the late Professor Errera® on the botanical side, and recently by Dr. Boulenger’ as a zoolo- gist. I am not competent to discuss Dr. Boulenger’s arguments, since their appraisement demands a famil- larity with vertebrate morphology which I do not pos- sess; but I wish here to consider EKrrera’s objections, as well as certain general considerations relating to animals and plants which have been held to militate against the Law of Irreversibility. It may be stated, broadly, that the opponents of Dollo’s Law regard it as disproved by the facts of ‘reversion’— that is by cases in which a variation appears which is interpreted as an atavistic® ‘throw-back’ to an hypo- thetical ancestor, and in which some character since lost by the species makes a renewed appearance. It will be necessary to analyse Errera’s criticisms—most of which conform to this type—in some little detail, since he claims that the instances he cites ‘‘suffisent 4 mon sens a réfuter la théorie de |’irréversibilité.’’ The first phenomenon to which he points as evidence is not, however, a case of varietal reversion; it is the apetalous character of cer- tain Caryophyllacee, Rosacex, ete., which he regards as a recurrence of ‘‘l’apétalie primitive des Angiospermes inférieures.’’ But this apetaly cannot be treated as fur- nishing an exception to the Law of Irreversibility if the more modern view be accepted which holds that the *I am indebted to Mr. C. Davies Sherborn and to Dr. G. A. Boulenger, for drawing my attention to Errera’s criticism, which is contained in Une lecon élémentaire sur le Darwinisme, Recueil d’cuvres de Léo Errera, Bot. Gén., 2, pp. 163-268, 1909. *Boulenger, G. A., L’évolution est-elle réversible? Considérations au sujet de certains poissons, Comptes rendus des séances de 1’Académie des Sciences, 168, p. 41 (séance du 6 janvier 1919). *In the present paper the word ‘atavism’ is used in a broad sense as synonymous with ‘reversion’—a sense in which it is habitually used in both French and English non-scientific literature. The attempt to restrict it in genetics to those cases in which some character of a grandparent is repeated in his grandchild seems indefensible when it is remembered that ‘atavus’ means ‘ great-great-great-grandfather’ and is also used in the general sense of ‘ancestor.’ 30 Arber—Atavism and Law Irreversibility. primaeval flower was of the eu-anthostrobilus type with a perianth. it is not necessary to labour this point, since Hrrera himself, at a later date, became disposed to regard the Ranales and Alismacee, rather than the Ape- tale, as primitive forms. And even if Errera’s original view be accepted, this case, though it might be then inter- preted as an exception to the ‘Law of Irreversibility,’ cannot be claimed as affecting the validity of the ‘Law of Loss,’ with which we are here more especially concerned. The other examples which Errera cites are the occa- sional development of a fifth stamen in the normally four-stamened Scrophulariacee, and also the case of Heinricher’s® curious ‘‘Iris pallida Lam, var. abavia.’’ In this Iris, by the selection of spontaneous variations, Heinricher obtained a form in which all six perianth members were alike and bearded, while there were six stamens instead of the normal three. This condition of the stamens was interpreted as an atavistic return to the type of androecium characteristic of the liliaceous stock from which the Iridacee are almost certainly derived, and in which there are two whorls of stamens, each with three members. These botanical cases may be compared on the animal side with Castle’s*® race of four-toed guinea pigs, which in this respect approached the ancestral form—presumably five-toed—more nearly than does the ordinary modern ecavy, with its three-toed hind foot. The occasional appearance of three-toed colts has also been interpreted as an example of the reversionary recovery of lost organs. It immediately becomes obvious, even on a casual scrutiny of these cases, that they possess one striking common characteristic—a charcteristic which seems to me to annul their significance as evidences of reversion. They all relate to meristic variations in which certain organs, of which at least one already exists, suffer an crease im number. The case of Iris pallida, var. abavia, is particularly interesting from this standpoint and seems susceptible of a different explanation from that given by Errera. The six perianth members are all alike and all bearded, 1. e., °Heinricher, E., Iris pallida Lam., abavia, das Ergebnis einer auf Grund atavischer Merkmale vorgenommenen Ziichtung und ihre Geschichte, Biol. Centralbl., 16, pp. 13-24, 2 text-figs., 1896. Castle, W. E., The Origin of a Polydactylous Race of Guinea-Pigs, Carnegie Institution of Washington, Publication No. 47, pp 17-29, 1906. It should be noted that Castle does not describe this polydactylism as reversionary, but significance in this connection has been attributed to it by others, e. g., Walter, H. E., Genetics, New York, 1913. Arber—Atavism and Law Irreversibility. ol they appear to correspond to the outer perianth members of a normal flower, the three inner being absent. In other words, the abnormal form of perianth may be inter- preted as due to the chorisis or dédoublement of the normal outer whorl. According to Hrrera, the six sta- mens are to be interpreted as incuding the three members of the outer whorl, and, in addition, the three members of that inner whorl which in the Ividaceae is normally sup- pressed. But it seems to me more reasonable to suppose that these three extra stamens are not the avatars of the defunct inner whorl, but have originated through the doubling of the members of the existing outer whorl; this suggestion has the advantage of postulating the same type of variation for both perianth and stamens. The important part which such secondary dédoublement may have played in the phylogeny of Angiosperms, has received full recognition from certain botanists who have tried to elucidate the history of the flower. Wernham"! for instance holds that when indefinite stamen numbers occur within the Archichlamydee, but outside the more primitive families, this condition may perhaps be inter- preted as due to secondary branching; the Opuntiales illustrate the extremest expression of this tendency to chorisis. In this connection it is possibly suggestive that—as Professor Punnett!? has pointed out—in more than one of the rare cases in which the evolution of domestic races appears to have come about by the addi- tion rather than the loss of factors, the interpolated fac- tor is of such a nature as to cause reduplication. . There may be some relation between such reduplicating factors and the chorisis to which we have just alluded. The view that such forms as a Jinaria with a five- chambered ovary,'* a five-stamened Stemodia*‘* or a four- toed guinea-pig, can be classed as ‘reversions,’ is also open to criticism on more general grounds. Such abnor- malities are only claimed as atavistic if they happen to correspond to those forms which on morphological or palaeontological evidence we suppose to be ancestral. But other similar cases, such as the various well known examples of polydactylism in man, are passed over in “Wernham, H. F., Floral Evolution; with particular reference to the sympetalous Dicotyledons, New Phyt., vol. 10, 1911 and vol. 11, 1912; see especially p. 111, vol. 10. * Punnett, R. C., Mendelism, 4th Ed., p. 80, 1912. *Crépin, F., Recueil de faits tératologiques, Bull. Soc. Roy. Bot. de Belgique, 4, pp. 276-8, 1 pl., 1865. “Errera, L., Pentstemon gentianoides et Pentstemon Hartwegi Bull. Soe. Roy. Bot. de Belgique, 17, pp. 182-248, 1878. 32 Arber—Atavism and Law Irreversibility. silence in this connection. And yet it would seem as log- ical to treat them as a throw-back to some ancestor with supernumerary digits, as to suppose the same thing on precisely corresponding evidence in the case of a six- stamened Jizs. And as Bateson? long ago pointed out— when dealing with just those types of numerical variation which have been claimed as exceptions to the Law of Irreversibility—a number of forms may occur through discontinuous variation, which, though equally perfect, cannot all be ancestral. Twenty-five years ago he wrote, ‘Tn the case of Veronica and Linaria, for example, a host of symmetrical forms of the floral organs may be seen occurring suddenly as sports, and of these, though any one may conceivably have been ancestral, the same can- not be supposed of all, for their forms are mutually exclu- Sive.’’ There is no doubt that the hypothesis of reversion has too often been employed by morphologists in an uncrit- ical spirit. To the students of variation and heredity we owe such lucidity and precision as the term has now gained, but yet biologists in general continue to use it as though it retained the nebulous quality which charac- terised it in Darwin’s day. The only instances of genu- ine atavism?*® of which we have any knowledge are those which consist in the synthesis by hybridisation of some original form which has now become split into different races by loss of factors. But this is a totally different thing from the sudden appearance of so-called ‘rever- sions’ in cases where there has been no hybridisation. The desire to interpret phenomena on the reversion hypothesis may perhaps be traced to our natural mental craving for similitudes, which seems easily to lead to a failure to discriminate between analogy and identity. A new form may recall some ancestor, near or remote, but; if the Law of Irreversibility holds, it cannot be described as re-incarnating the qualities of that ancestor, except in the loose and metaphorical sense in which senility is described as ‘second childhood.’ It is probably not going too far to say that there is no such thing as the retracing of steps, either in the life of the individual or of the species: in the words of the old proverb, ‘‘The baked bread can never go back to the dough.’’ Balfour Laboratory, Cambridge, England. * Bateson, W., Materials for the Study of Variation, p. 76, 1894. 7° The view that teratology reveals no undoubted case of reversion, is maintained by Demoor, J. Massart, J. and Vandervelde, E., Evolution by Atrophy, Int. Sci. Ser. vol. 87, 1899. o Very—On a Possible Limit to Gravitation. 28 Arr. V.—On a Possible Limit to Gravitation;* by Frank W. VERY. General Statement of the Argument. It is assumed that gravitation acts by means of longi- tudinal waves of alternate condensation and expansion in a universal medium which is also a magnetic medium, or ‘‘magnetic aura,’’ composed of least parts, or mag- netons, and which is subject to magnetic laws. Hence the gravitational wave at any instant is assumed to coin- cide with a magnetic equipotential surface and to follow in its progressions the curves of magnetic lines of force. Reasons are given for believing that the sphere of action of a given galactic mass of stellar material does not extend to infinity, but is contained within a definite aural ‘“cell,’’ or is limited by the vortical motions of a partic- ular body of the universal aura which is independent of neighboring similar bodies, possibly because there is repulsion between them, so that interference is impos- sible. Speaking relatively, the galaxies are rather closely packed, in total disagreement with the sparsity — of stellar distribution; and the galaxies have also much greater speeds than the relative speeds of the stars which compose them; but nevertheless the galaxies show hardly any appearance of collision or interpenetration—noth- ing which cannot be explained as variation in a general magnetic control. in confirmation of this view may be cited Van Maa- nen’s measures of the internal motions in Messier 101. The motions are away from the center, as if controlled by currents in the general medium, that is, these motions are not such as would be anticipated under the gravita- tional attraction of a central mass; and the flow appears to follow a law of the inverse cube of the distance which would be appropriate to a magnetic control. An attempt is made in this paper to devise a scheme of an atom, composed of least gravitative units, which shall be capable of performing these functions and of sustaining these relations to a general magnetic medium; and it is shown that gravitational waves having a frequency not * This paper was presented at the Twenty-first meeting of the American Astronomical Society at Albany, August, 1917 (abstract in Publications of the Society, vol. 3, p. 335), but has been slightly modified since then. Am. Jour. Sct.—FourtTx Series, Vout. XLVIII, No. 2838.—Juty, 1919. 3 34 Very—On a Possible Limit to Gravitation. far from that of a light-wave will account for the phe- © nomenon, if circumscribed by a boundary; but that, otherwise, it is not easy to account for the action on mechanical principles. Hence it is concluded that, some- what as the molecules of gases move in every direction among themselves, but are nevertheless controlled by the more general currents of the larger gaseous mass, so the individual motions of stars, or of lesser star clusters, are local and under the control of a more general movement of the body of aura which contains them. According to the kinetic theory of gases, the pressure in a gas is that due to the momentum of the colliding molecules themselves as finally refiected from the con- taining walls of the enclosure. Without a lhmiting wall, the given mass of gas would expand indefinitely until its molecules ceased to collide and there would be no pres- sure. Ina galactic mass, on the contrary, the individual stellar units do not collide, and the compression is not produced by the onward motion of the stellar ‘‘par- ticles,’’ or of their least component atoms; but it is pro- duced in the containing medium by an internal mechan- ism within the atom itself, thus in an entirely different way. Nevertheless, as in the case of the theory of gases, it is difficult to see how there can be any pressure unless there is a-‘retaining wall. Such a cell wall for the gravi- tational pressure is presumably a discontinuity in the aura produced by its vortical motion. Thus the aural cell may be likened to a gigantic ‘‘vortex-atom.’’ Gravitational Potential is a Strain in the Magnetic Medium caused by Electric Stresses. Until quite recently, one of the chief characteristics of eravitation has been supposed to be its universality. The attraction of large and small neighboring masses in the Cavendish experiment, the union of sun and planets, and of pairs of suns forming binary stars and separated by distances much exceeding those of the planets, all appeared to follow Newton’s law with remarkable accu- racy, and to be completely dissociated from every other form of physical force. No mode of screening this force has yet been discovered. If limitations to gravity exist, they must be sought in other ways. Gravitational potential appears to consist in a state of strain set up in the magnetic medium through the inter- Very—On a Possible Limit to Gravitation. 35 action of waves in the medium which constitute the external gravitational field of the electronic movements which are matter. We admit that matter is first of all a circulatory movement of the two sorts of electricity (equivalent to an electric doublet) whose least com- ponents are everywhere accompanied by indefinitely extended and dynamically proportional vortices in the magnetic medium. It would appear, however, that, though no other than the magnetic medium can be con- cerned in the action, and though the gravitational lines of force are ultimately controlled by magnetic vortices, the gravitational forces are not to be confounded with magnetic forces. Rutherford maintains that the positive electricity in an atom is a central mass of very minute size, placed there like a sun (as in Larmor’s atom) to guide the orbital motions of the electrons. It has been supposed that the positive nucleus of an atom must be very minute, because collisions of alpha particles with them are infre- quent; but contact in this case does not mean hitting the bull’s-eye of atarget. It means a sufficiently close juxta- position of two interpenetrating fields of motion in the magnetic universal atmosphere to produce reaction; somewhat as the fields of force of light-rays everywhere interpenetrate without interfering, except where there is an exceptionally precise superposition of the extended fields, with similar, or with opposing phases, reinforcing the movement on the one hand, or destroying it on the other. Now this assumption of central position is unnecessary ; because Newton showed that the gravitational attraction of a spherical shell of matter is precisely the same as if all of the matter in the shell were concentrated at the center. Nor do we know just what it is that constitutes what we call an ‘‘attraction.’’ A soap bubble is held — together as one piece by a circumferential pressure everywhere centripetally directed. We explain this as the result of surface tension in a liquid; but if we were ignorant of the existence of the surface tension, there would be nothing to distinguish this from a case of cen- tral ‘‘attraction.’’ Moreover, if all of the positive elec- trification is concentrated in a single electric mass, it would follow that the heaviest atoms must have the smallest central nuclei (because intensity of electrifica- 36 Very—On a Possible Limit to Gravitation. tion increases as the radius diminishes), which seems a bit paradoxical, since it is natural to suppose that increased mass comes from the addition of new acces- sions, and this could happen if we suppose that the minute positive electrons are symmetrically arranged in the form of a thin shell. It is also in accordance with all of the electrical analogies that the static part of the electrification should seek the surface. The rapidly moving electrons are elements of electric current, but this does not prevent them from also playing the part of static charge in potency, even though this charge may be neutralized. General Scheme of Electronic Motions within the Nucleus. In considering the motions of the negative electrons, some modifications are needed. The Larmor-Bohr- Rutherford atom is likened to a solar system in which the negative electrons, like the planets, move substan- tially in a single plane. This may be true of certain satellite electrons concerned in chemical action, but I would suggest that not all of the orbital planes need coin- cide. The larger part of them may be parallel, but dis- tributed on the spherical surface of the atom. The resultant effect will be the same in many respects as if all were in one plane. ‘This leads to a consistent scheme of motions according to the following plan: “Assume as a preliminary conception that all of the electrons in a meridional section of the atom are either ring-shaped, or else approximately oblate spheroidal particles of a uniform size (equatorially expanded by centrifugal pressure of the spin) and with a common (let us say, clockwise) rotation over a given half-section as seen from our point of view; and that they are revolving rapidly in planes parallel to the equator of the atom (with the electrons juxtaposed, pole to pole, or forming virtual vortex-filaments) in definite, but not necessarily invariable orbits, since they may pass into spirals whose radu vectores alternately expand and contract when the elastic surface of the atom is disturbed by a collision. The electrons having like rotation mutually repel one another, except in the direction of the spiral vortex-fila- ment; and this may compel some motion of the orbital planes and change of configuration of the orbits during radiation. Juxtaposed electrons on either side of an lod Very—On a Possible Limit to Gravitation. 37 equatorial plane are mutually repelled polewards, and this would split the atom into two halves were there not a restraining force. The electrons are supposed to be rotating at enormous speeds and all in a given set in the same direction of spin in respect to the orbital motion, which will necessarily give the appearance of opposite rotations in the two halves of the same meridional section of the atom. We must presume that these motions are so nicely balanced and take place in a medium so free from viscosity that they form a perpetually regenerating system. Particles of the sort described are supposed to attract outside particles in proportion to the energy of the elec- tronic motion, and this will vary in direct proportion to the number of electrons included in the atom. The attraction will apparently be that of pulsatory motion, or will form waves of longitudinal vibration in the uni- versal aura, passing outward into forms which at first approximate to perfect spheres. Owing to the perfect sphericity of the atomic surface, the combined vibrations of its electrons will generate a composite spherical wave in any case. The orbital motions give rise to vortices in the magnetic medium which are the cause of inertia, and the pulsatory motions produce the changes of density which are the origin of gravity. The conception, it seems to me, affords a rational basis for the conclusion reached by Fessenden on general physical principles, but without attempting to devise details of mechanism, namely, that ‘‘the inertia of matter is due to the electro- magnetic inductance of the corpuscular charges, and gravitation is due to the change of density of the ether surrounding the corpuscles, this change of density being a secondary effect arising from the electrostatic stresses of the corpuscular charges.’ The Nature of Positive Electricity. As to the nature of positive electricity which is always associated with the negative electrons in the atom, we know nothing, save that it has opposite properties to negative electricity, so that if the shell of positive elec- tricity is composed of discrete positive electrons, arranged in circular strands which revolve in the same general direction as the negative electrons and nearly * Science, N. S., vol. 12, p. 327, August 31, 1900. 38 Very—On a Possible Limit to Gravitation. parallel with them (though the discrete positive electrons may be rotating in the opposite sense to the subjacent negative ones), the magnetic field of the positive elec- trons will have the opposite sign to that of the negative electrons. The positive strands will repel each other, and the positive shell will be strained almost to the bursting point, being retained in position solely by the attraction of the enclosed sphere of negatives. In this view, the sun-and-planets analogy does not hold in the atom, at least not as to the gravitational properties of the nucleus, but the positive and negative masses are presumably of a like order of magnitude or even identical save in aspect; and they are complementary in the sense that one requires the other, whereas we can conceive of a sun without planets. If the two spheres are not exactly con- centric or not perfectly equal, they form the equivalent of a doublet,” and the total electric value of the combina- tion is that of a minute residual, or difference, while the gravitational effect is that of the sum of the gravita- tional forces which do not interfere. If the combined revolutions and potencies of positive and negative electrons are exactly adjusted, there will result a magnetically neutral atom; but if there is a dif- ference in the positive and negative revolutionary fields within the atom, it becomes a magnet. The Question of Orbital Spirality. Professor G. Johnstone Stoney has been the only one I know who has attempted to apply the doctrine of spiral orbits of electrons to explain harmonic series in spectral lines, finding in the case of the A and B groups of the atmospheric spectrum (first described in detail by Lang- ley in 1878 in the Proceedings of the American Academy of Arts and Sciences) that he could account for the remarkable structure of these groups by compounding oppositely rotating spirals of diminishing amplitude which were supposed to give respectively the red and violet components of the pairs of a train. The resultant > Cohesion between atoms or molecules does not arise from gravitational attraction, but follows a law of proportionality to the inverse fourth power of the distance, or after the analogy of the gravitational model, is equal to Am,m,/r*. Both Fessenden and Sutherland have shown that this follows as a consequence if we assume the particles to be of the nature of electric doublets. See especially W. Sutherland on The Electric Origin of Molec- ular Attraction, Phil. Mag., Ser. 6, vol. 17, p. 657-670, May, 1909. Very—On a Possible Linut to Gravitation. 39 is an exceedingly elongated ellipse, subject to these per- turbations: (1) Decrease of amplitude; (2) diminution of periodic time; (3) slow apsidal motion opposite to the orbital revolution of the electron; (4) a slight fluttering motion hke nutation; (5) a further shght secular change in the form of the ellipse. As to whether the spiral is the primary motion and the elliptic relations a concomi- tant resultant of perturbations, or vice versa, may not be easy to determine from the mathematics. The suppo- sition as thus stated by Stoney is somewhat vague, and in spite of appearances of spiral relations in the wave- lengths of a series of lines forming a group, or band in the spectrum, it is not easy to see how such definite wave- lengths can result from a perpetually and gradually modified series of spiral circulations. Besides this, the oxygen series relates to atoms in molecular combination, and not to dissociated atoms which give quite a different and much simpler spectrum. A more reasonable supposition is that of Bohr, of which a slight modification is described by Milhkan in Science,® where it is shown that certain orbits whose radii are in the ratio of the squares of the ordinal numbers are stable, but all intermediate orbits are unstable. When, therefore, the position of an electron is disturbed, it passes explosively to the next stable orbit and may repeat the process several times in succession, each transfer giving rise to an electromagnetic vibration in the period of the new orbit. The number of transfers depends upon the thermal energy available. Under the moderate thermal conditions of our laboratories, often only five members of the Balmer hydrogen series are pro- duced and at most twelve; but in the hottest stars over thirty appear. . In any case, the fact of internal orbital revolution of certain electrons in an atom, presumably the satellite or characteristic electrons, is demonstrated by the Zeeman effect, and by the wonderful agreement in the quantita- tive values which Millikan has deduced from Moseley’s measurements (op. cit.). The radiation equation 1% (mv?)—= hv, where m is the mass of an electron. v its orbital velocity, h = Planck’s radiation energy factor, and v =the vibrational frequency, represents the energy expended in reversing the electric sign, that is, in over- : Cone and Atomic Structure,—Science, N. S., vol. 45, p. 321, April , 1917. ; 40 Very—On a Possible Iinut to Gravitation. turning the axial pose of a particular electron which, although the direction of motion is not changed, is as if the orbital velocity had been reversed. Except for these instantaneous reversals in the generation of light-. quanta, the electronic revolutions never cease, for the atom is a form of extraordinary or almost perpetual endurance, and of relatively enormous energy. The agreement of Rydberg’s frequency constant N with the value derived from an application of Kepler’s laws to the electronic orbits constitutes, as Millikan remarks, ‘‘most extraordinary justification of the theory of non- radiating electronic orbits,’’ and verifies at least this much of Bohr’s theory. The External Gravitational Potential. It is now evident that every atom consists of two parts: (1) the very circumscribed space in which the above mentioned electronic movements are carried on; and (2) the indefinitely extended field of gravitational potential, or strain, in that universal medium which, following Swedenborg, I shall call the magnetic aura, or simply the aura. The first requisite for any proposed explanation of the facts of gravitation, if it be admitted that a genuine explanation will be of a mechanical nature, is some tenta- tive scheme of a gravitational unit, which shall be capable of generating a longitudinal wave of alternating expan- sion and compression in the universal magnetic aura. In seeking for such a possible working model, I shall further assume that the aura is divided into complex vortices of galactic dimensions, and that an individual complex vor- tex constitutes a single independent aural ‘‘cell’’ within which the gravitational motions of its combined masses are confined. ; Since all of the motions of the aura are vorticose, this may apply equally to the ultimate direction of propa- gation of a gravitational wave in the medium. This point may be open to discussion, but is here adopted ten- tatively on the plea that the electron is probably a polar vortical particle.* The wave, therefore, though at first 4In another paper (‘‘The Luminiferous Ether,’’ Occasional Scientific Papers of the Westwood Astrophysical Observatory, No. 2, p. 36) I have suggested that the electron itself probably has an internal vorticose motion and polar structure which adapt it to the required function even in its pulsations. But the electronic complex, the atom, is always a perfect sphere. Very—On a Possible Limit to Gravitation. 41 spherical by close approximation, may ultimately pass into and coincide with a complex of magnetic equipoten- tial surfaces, so that the wave-propagation is not radial, save by close approximation at the start, but follows the direction of the curved lines of magnetic force in the field as finally ‘‘magnetically’’ controlled, and thus returns into itself at the point of initiation. This conception has some analogy with Newcomb’s idea that space returns into itself through a fourth dimension; but the latter is highly recondite, and indeed transcendental, whereas my proposition is quite simple and is not disproved by any known facts. Newcomb’s conception appeals to me strongly as a feasible means of passing through an inter- mediate from the world of nature to a world of pure spirit which is not in space of three dimensions; and perhaps the full explanation of gravity will require this further extension of rational thought into the region of genuine causes; but for the present this greater problem and border region of science may be omitted. If the magnetic analogy be accepted, no energy is wasted in maintaining the mechanism of gravitation. Moreover, the elasticity of the aura is almost infinite, so that the velocity of propagation of the gravitational wave is enormously greater than that of light.» According to Professor Fessenden’s computation,® the velocity of the gravitational wave is 5 that pyrox- ene is a high temperature mineral, while amphibole is a lower temperature form. The change from one to the other being a paramorphic (or ‘‘autometamorphic’’) one—a change readily brought about by the stresses of dynamic and static metamorphism,—the inversion of pyroxene to amphibole furnishes some aid in the problem in hand. If a large amount of pyroxene, such as augite, is found in an amphibolite it suggests an igneous origin. But under the stress of severe metamorphism this inver- sion may be complete. Martin?® found this to be true of the amphibolite inclusions in the granitic rocks in the Canton sheet (St. Lawrence Co.). Thus the absence of augite does not necessarily prove a sedimentary parent- age, but merely suggests it. This criterion, like the former, is therefore regarded as inconclusive. Hunting for additional criteria, the writer investigated the feldspars in turn. It was found that the igneous types usually contained a simple range of feldspars, such *® Cushing, H. P.: N. Y. State Mus., Bull. 169, p. 19 and Bull. 191, p. 15, 1914. *4 Johannsen, Albert: Jour. Geol., 19, p. 319, 1911. * Hilsden, J. V.: Principles of Chemical Geology 1910, p. 114. Becke: Tsch. Min. u. Petr. Mitt., 16, pp. 327-336. Clarke, F. W.: U. S. Geol. Surv., Bull. 616, p. 386. Lacroix, Minéralogie de la France, I, 1893-1895, pp. 668-669. “Martin, J. C.: N.Y. State Mus., Bull..185, p. 157, 1916. 62 Alling—Problems of Adirondack Precambrian. as 10% orthoclase and 20% andesine, while the sedi- mentary rocks frequently exhibited a motley collection; covering a much wider range. Very commonly soda- orthoclase, microcline, perthite, oligoclase and labra- dorite were seen in a single microscopic slide. This was explained with the aid of the equilibrium diagram of the orthoclase-albite-anorthite system proposed by Vogt,?" Marc,”** Becke,?? Harker,®° supported by the observations of Day,** Allen,** and Warren.” If the feldspar compo- sition, in the magma, was on the potash side of the eutectic line the resulting crystals would be dominantly the orthoclase type of feldspar, while if it was on the other side plagioclase (plus a little potash feldspar) would result. But if the position of the molten feldspar was on or near the eutectic line the solid minerals would be divided on freezing into orthoclase (carrying a little soda feldspar in solid solution) and plagioclase. The criteria may be summed up as follows: Sedimentary Origin Igneous Origin Original Quartz High pyroxene content Motley collection of feldspars Evenly ‘‘split’’ feldspars How successfully these criteria have been applied to amphibolites whose origin was not forthcoming from the field relations cannot as yet be stated, but the hope is entertained that some progress has been made in this difficult problem. 4. The Algoman Series. The Anorthosite.—The anorthosite-syenite-granite and gabbro series have received a great deal of attention. It was Cushing** who first pointed out in the Saranac- Long Lake Region that the anorthosite was the oldest rock of the group, by finding dikes of the syenite cutting the anorthosite. The writer can bring into court two 7 Vogt, J H. L.: Silikatschemelzlosungen, 1914, II, pp. 120-1. *° Becke, F.: Tschermak, Min. Petr. Mitt. (2) 25, 106, pp.. 361, 383-85, 1906. * Marc, Robert: Vorlesungen uber die Chemische Gleichewichtslehre und ihre Anwendung auf die Probleme der Mineralogie, Petrographie und Geolo- gie. Fig. 68, pp. 69, 111-112. *° Harker, Alfred: Natural History of Igneous Rocks, p. 250, 1911. Day, A. L., and Allen, E. T.: Carnegie Inst., Publ. 31, 1905. *° Warren, C. H.: Am. Acad. Sci., 51, No. 3, pp. 127-154, 1915. *% Cushing, H. P.: N. Y. State Geol., 20th Ann. Rept., p. r25-r46, 1900; N. Y. State Mus., Bull. 95, pp. 318-322, 1905. N. Y. State Mus., Bull. 115, p. 481, 1907. Alling—Problems of Adirondack Precambrian. 638 new occurrences showing the anorthosite cut by dikes of the syenite. In the St. Regis quadrangle, just south of Mountain pond a dike of quartz syenite cuts the anortho- site; the other exposure is in the Saranac Lake sheet two miles west of Gabriels (Paul Smiths Station) beside the state road. The anorthosite has been the subject of a very valuable paper by Bowen.?* From the study of the binary system of solid solutions, albite-anorthite, he concluded that the anorthosite, essentially a labradorite rock, was not molten as such, suggesting that the anorthosite is a dif- ferential phase of a gabbroic magma. He pictures a huge laccolith invading and splitting the overlying Gren- ville series, which differentiated into an upper layer of syenite-granite and a bottom one of gabbro and an inter- mediate zone of anorthosite. The suggestion of a laccolith is a new conception and may furnish the expla- nation of some of the obscure problems of the Algoman. The writer, however, takes exception to Bowen’s view that a genetic relation exists between the syenite and anorthosite. The chill phases of the syenite are fre- quently monzonitic to dioritic in composition. As the ferromagnesian minerals are commonly pyroxenes the rock as such can be called gabbroic but in no case has it been the writer’s experience that a ‘‘syenitic’’ phase of the anorthosite occurs. ‘The writer grants the close kin- ship between the anorthosite and the gabbro but ques- tions a similar relation between the anorthosite and the syenite, although realizing that they are nearly contem- poraneous in age. Bowen’s suggestion that the Algoman rocks are lacco- lithic rather than batholithic is a valuable one. One of the problems of the Adirondack Precambrian is to account for the non-discovery of the Grenville floor. If the Algoman magma arose, and injected the overlying Grenville as a huge laccolith, it would, perhaps, account for this failure. This suggestion, however, assumes that the syenite has been derived from a single mass. As Cushing points out,** it is difficult to account for the pres- ent exposures on this basis. To explain the outlying syenite and granite bodies away from the anorthosite the postulation of several other magmas, which may have ** Bowen, N. L.: The Problems of the Anorthosite, Jour. Geol., 25, p. 223, 1917. * Cushing, H. P.: Jour. Geol., 25, No. 6, p. 508, 1918. 64 Alling—Problems of Adirondack Precambrian. been only slightly later in age than the anorthosite, seems necessary. Bowen does not discuss the Whiteface type of anor- thosite, a rock studied and named by Kemp. In the Lake Placid sheet the writer has found limestone-contact-zones due to the igneous activity of the Whiteface (and pos- sibly one due to the ‘‘Mt. Marcy’’) type of anorthosite. This shows that mineralizers were not entirely lacking, contrary to Bowen’s conclusions. The age relations of the two types, in so far as the writer knows, have not been established. The writer’s feeling is, however, that we are dealing with two separate intrusives. In the Mt. Marcy sheet, on the west slopes of Baxter mountain, large xenoliths of the Mt. Marcy type, highly foliated, are engulfed in a mass of the same type of anorthosite. A similar state of affairs is seen at Split Rock Falls®® in the Elizabethtown quadrangle, where a peculiar type of rock is developed. How are we going to interpret these observations and reconcile them with Bowen’s conclusions? The Gabbro.—Away from the large areas exposing the Algoman gabbro this rock occurs as pipes and stocks. This characteristic behavior is beautifully shown in the North Creek sheet, as W. J. Miller has pointed out. But on the Dixon-Faxon graphite properties at Graphite the Algoman gabbro occurs as true inter- and intra-forma- tional laccoliths—a most unexpected form of an igneous mass. Swede Pond mountain seems to have been formed by the injection and development of a laccolith beneath, doming up the quartzite, so that distinct and opposite dips are observable on the north and south slopes of the hill.. One small laccolith on the shore of North Pond is just unroofed by the construction of a state road. The Term ‘*‘ Algoman’’.—The name Algoman, perhaps, needs a word in the way of explanation. The term ‘‘anorthosite-syenite-granite-gabbro series’’ is obviously a clumsy expression. Miller has employed the term syenite-granite in his writings. To those who have followed the progress made by the Adirondack geologists no confusion arises. But with the recognition of the old granite, which Cushing regards as Laurentian, the need for an analogous name to apply to the later series becomes very desirable. While it would have been more * Kemp, J. F.: N. Y. State Mus., Bull. 138, p. 39, 1910. Alling—Problems of Adirondack Precambrian. 65 conservative to have chosen a more local name than ‘¢Algoman,’’ yet Cushing has proposed a term in ‘‘Laurentian’’ which has from time to time possessed different shades of meaning. The writer does not claim that the term Algoman as applied to the later series of eruptives is original with him. He has heard it used in the field, perhaps more commonly by St. Lawrence county geologists. The Precambrian rocks of Canada have been studied in sufficient detail to furnish data for numerous correlation tables, twenty of which have been examined. There is a striking similarity in nearly all; there are only two periods of igneous activity prior to the Keweenawan. The old granite is regarded as Lau- rentian, hence, if we follow W. G. Miller and Knight*’? we are, perhaps, compelled by the force of circumstances to employ the term Algoman; it furnishes a much desired ‘“handle.’’ THE GABBROIC DIKES. The writer has encountered several dikes, usually only 3-to 4 feet wide, that are of peculiar composition. They are strikingly equigranular and composed of labra- dorite, augite, garnet and magnetite. Sometimes horn- blende and biotite occur in addition. Mineralogically they can be classed as gabbros but no diabasic or gab- broic texture is visible even under the microscope. One occurs at Euba Mills, in the Elizabethtown quadrangle, another a mile south of the town of Saranac Lake on the shore of Lake Flower, a third one was seen on the Blue Ridge-Newcomb road in the Schroon Lake sheet. Still another occurs at the eastern entrance of the Gulf, in the Ausable sheet. In each case they are cutting anorthosite. Undoubtedly more will be encountered as field work is continued. DIABASE AND TRACHYTE. On the Faxon Graphite property, Bolton quadrangle, Mr. D. H. Newland pointed out to the writer a diabase dike which has assumed a most peculiar form. It is of normal Adirondack diabase, olivine free. Instead of behaving like the rest of the dikes of the region it has failed to reach the surface, expending its energies in the formation of a laccolithic body some 300 feet long and 25 feet thick. It splits the ‘‘Dixon’’ schist into two seams.. 7 Miller, W. G., and Knight, C. W.: Jour. Geol., 23, p. 588, 1915. Am. Jour. ee SERIES, Vout. XLVIII, No. 283.—Juty, 1919. 66 Alling—Problems of Adirondack Precambrian. This unusual laccolithic diabase is exceptionally well shown by the excavation made for the state road that runs from Chestertown to Hague. Kemp and Marsters?* have emphasized the variations in the diabase dikes, especially those occurring in the Fig. 3. LAKE ecg A Ro EATS Sm 0 500 1000 1500 GP Amp FEET cn WHALLON BAY Split Rock | Point ) TAREE STORY DIKE” [==] Bostonite aaah Camptonite Rx Diabsse Grenville Fic. 3. Sketch map and detail drawing of ‘‘Three story dike’’ on Split Rock point, Lake Champlain, N. Y., H. L. Alling, 1918. Champlain Valley. Just north of the lighthouse on Split Rock, Willsboro sheet, a group of dikes of unusual interest is located. When Kemp and Marsters visited this locality a boathouse, situated astride them, obscured them from view. This building has subsequently been removed, giving access to them. Apparently a dike of nearly normal diabase, originally 6 or 7 feet wide, per- haps slightly porphyritic and approaching an augite * Kemp, J. F., and Marsters, V. F.: U.S. Geol. Surv., Bull. 107, 1893. Alling—Problems of Adirondack Precambrian. 67 camptonite, fractured longitudinally to allow a second and later dike of hornblende camptonite to intrude. This was about 3 feet wide. ‘This in turn split to allow a third dike to sandwich its way in. This is a typical bos- tonite dike 2 feet in width. Hach dike has developed chill phases upon its neighbor; a narrow contact zone of several inches occurs between the porphyritic diabase and hornblende camptonite. A more ideal exposure to show the age relations of the dike rocks cannot be imagined. The Age of the Faulting in the Adtrondacks. It has impressed the writer that the faults are not all of the same age. With such complex geology as is shown in the region it would seem remarkable if the faults had been contemporaneous. Positive proof of various ages was secured in the Saratoga sheet on the property of the Graphite Products Corporation, 4 miles north of Sara- toga Springs. The graphite schist occurs as two (and possibly as three) outcrops due to repetition by faulting. . The fault lines run east and west, which are abruptly cut off by the north and south fault (McGregor fault) that brings the Canajoharie shale in contact with Gren- ville. Thus there is post-Grenville-pre-Cambrian fault- ing as well as that occurring since Cambrian times. A mile south of the town of Saranac, one of the unusual gabbroic dikes has re-cemented a fault zone in the anor- thosite; engulfing brecciated fragments as xenoliths demonstrating pre-gabbroic dike faulting. When the region is made the subject of a serious physiographic Ey the relative ages of the faults should be kept in mind. | Summary. The following points were brought to light or empha- sized during a detailed investigation of the Adirondack Graphite Deposits during 1917 and 1918: 1. That the Grenville strata have been extensively isoclinally folded. 2. That the stratigraphic units formerly proposed in attempting to put the Grenville in order are too large, but when smaller units and the graphite schists are taken as a basis, then it is possible to do something with the 68 Alling—Problems of Adirondack Precambrian. old sediments. One thousand feet of the series have been studied in detail and subdivided into 12 formations which can be traced over considerable area. 3. That individual phases of the Saranac Series may be some one or other of the well recognized rock units, yet it is quite possible that other phases cannot be so classified. 4. Recognition of the presence of an ancient meta- gabbro antedating the Laurentian granite. 5. Recognition of the presence of a granite (quartz monzonite) older than the anorthosite-syenite-granite- gabbro series. This is the Laurentian granite. 6. The establishment of a metagabbro closely follow- ing the intrusion of the Laurentian granite. 7. Some amphibolites were found to be of sedi- mentary origin, that is, members of the Grenville series, while others are metagabbros. Criteria for the recog- nition of the different types are here presented. 8. The occurrence of the Algoman gabbro and the normal diabase in laccolithic bodies. 9. The presence of some peculiar gabbroic dikes. 10. ‘The post-diabase age of the camptonite and bos- tonite dikes. 11. That the faults of the Adirondacks are not all of the same age. 400 Cxford St., Rochester, N. Y. Chenustry and Physics. 69 SCIENTIFIC INTELLIGENCE. I. CurmistRY AND Puysics. 1. The Arrangement of Electrons in Atoms and Molecules.— Irvine Langmuir has presented an important contribution to this interesting subject. He says that the problem of the struc- ture of atoms has been attacked mainly by physicists who have given little consideration to the chemical properties which must ultimately be explained by a theory of atomic structure, and that Kossell and also G. N. Lewis have had marked success in attack- ing the problem in connection with the properties and relation- ships indicated by the periodic system. Lewis has reasoned from chemical facts that the electrons in atoms are normally stationary in position, that they arrange themselves in a series of concentric shells, the first shell containing two electrons, while the other shells tend to hold eight. The outermost shell, how- ever, may hold 2, 4, or 6 instead of 8. The eight electrons in a shell are supposed to be placed symmetrically at the corners of a cube or in pairs at the points of a tetrahedron, and when atoms combine they are supposed to hold some of their outer electrons in common, two electrons being thus held for each chemical bond. Kossell has conceived the electrons as located in a plane in con- centric rings, rotating in orbits about a nucleus, and his theory has many points of similarity to that of Lewis. It is pointed out by Langmuir, however, that each of these theories in its present form fails to explain the properties of a large part of the ele- ments, especially those of higher atomic weights. Langmuir has therefore advanced a theory of his own, extend- ing Lewis’s idea of the cubical atom, and making use also of certain ideas of Kossell. His speculative postulates and conclu- sions are so numerous that no attempt can be made to give a summary of them here, but a few aspects of his theory may be presented. In attempting to determine the arrangement of elec- trons in atoms he has been guided in the first place by the numbers of electrons which make up the atoms of the inert gases, in other words by the atomic numbers of these elements, namely, helium 2, neon 10, argon 18, krypton 36, xenon 54, and niton 86. Rydberg has pointed out that these numbers are obtained from the series N=2(1-+ 2? + 2? +37 + 3? + 47% +) Langmuir draws the conclusion that these numbers represent the electrons in perfect atoms with complete outer shells, and thus decides upon the numbers of electrons in each shell. He believes that the electrons of any given atom are distributed through a series of concentric (nearly) spherical shells, all of equal thickness, while the mean radii of the shells form an arith- 70 Scientific Intelligence. metic series 1, 2, 3, 4, and the effective areas are in the ratios 1 22? - 3? 2 Aas That each shell is divided into cellular spaces or cells occupying equal areas: That the first shell contains 2 cells, the second 8, the third 18, and the fourth 32: That each of the cells in the first shell can contain only one electron, but each other cell can contain either 1 or 2: That all of the inner cells must have their full quota of electrons before the outside shell can contain any: That no cell in the outside layer can contain two electrons until all the other cells in this layer contain at least one. It appears that this theory of atomic structure not only explains in a satisfactory manner the general properties and relationships of all the elements, but also gives a theory of the formation and structure of compounds which agrees excellently with the facts——Jour. Amer. Chem. Soc., 41, 868. H. L. W. 2. Qualitative Chemical Analysis; by WiLFRED WELDAY Scorr. 12mo, pp. 350. New York, 1918 (D. Van Nostrand Company. Price $2.50 net).—This is the third edition, com- pletely revised and enlarged, of an unusually extensive text book on qualitative analysis. One of the satisfactory modifications of this last edition is the introduction of a large number of chemical equations for the purpose of explaining the reactions. The book is essentially a laboratory guide with extensive directions for the work of students, but it gives much also in the way of expla- nations, notes and systematic questions for class-room use. There are many tables explaining analytical operations, showing the reaction of metals and acids, the properties of inorganic com- pounds, ete. The book is an impressive one from the very large amount of information that it presents, and for the generally excellent manner of presentation. Perhaps the course that is given may be considered too elaborate for many classes of beginners, but it must be admitted that it is easier to omit portions of an exten- sive text book than to supply deficiencies with one that is too short. There is room in many cases for differences of opinion in regard to the selection of analytical methods, but it may be said that in the book under consideration several methods of detection or separation are frequently described, and that the methods are generally well chosen. fs De "0 3. The Origin of Spectra.—lIn a recent theoretical paper by J. J. THOMSON an explanation of the origin of spectra is given which leads to results of the right kind and which is very helpful in forming a mental picture of the processes of radiation. Of course, the author does not claim that his point of view is the only correct one, on the contrary he points out the possibility of an infinite number of laws of force each of which would account for the observed facts and not conflict with well estab- lished electrodynamical principles. Chemistry and Physics. 71 In the first place, if the law of electric force had the form r?(1—c,r*) (1—e,r*) (1—e,r+), where c,, c,, c, are of the order of atomic distances, and r is the distance from the positive nucleus, there would be no lack of accord with the inverse square law for actual experimental distances, which are always enor- mous in comparison with atomic magnitudes, 10°? em. On the other hand, the force would change from attraction to repulsion when r assumed any one of the values c,, c,, c;. Since the law of force within the atom is not known there is no objection to assuming the alternation of sign involved in the above expres- sion. Instead of using the preceding multiplier of 1-7, Thomson prefers the factor (sin cw) /cu, where u—1/r. Inside the atom, if atomic dimensions are comparable with c, there will be a series of positions of equilibrium for an electron determined by cu == "7 where n is an integer. Thus even if there is only one positive charge and one electron (hydrogen) there may be a sinely infinite series of atoms with the electron at distances from the center represented by r—=c/nz. The times of vibration of the electrons about these positions would be different, so that a collection of such atoms could give rise to an infinite number of lines both in the absorption and emission spectra. Among other things, this conception accounts qualitatively for the observed decrease in the intensity of spectral lines of a given series as the term number of the line increases. Further progress is made by supposing that magnetic instead of electric forces are predominant in determining the electronic vibrations. In this case it is convenient to assume that the value of the magnetic induction, at a point of equilibrium at a distance r from the center, is given by »(a?—r?). This distribution of magnetic force is not @ priors improbable as it is that inside a sphere uniformly electrified and rotating like a rigid body. It is then shown that the frequencies in these positions would be proportional to (SS — =), which expression represents a series of the Balmer type. If, in addition, the place r=a, where the magnetic force vanishes, is also a place where the elec- : c ; : tric force vanishes, Piped where m is an integer, and the : 1 1 : expression for the frequency becomes = =), where C is a : / constant. The type of atom which is required to satisfy the assumptions made in the analysis is described as follows. ‘‘This atom consists of a field of electric force which may be regarded as made up of a series of shells of attractive and repulsive force following one another alternately, the radii of the boundary of these shells, which are places where an electron would be in equilibrium, being in harmonical progression. Superposed on the field of electric force is a field of magnetic force, also 72 Scientific Intelligence. arranged in shells, the outer boundary of the magnetic field coin- ciding with a place where the electric force vanishes.’’ When more than one electron forms a part of the normal atom, the position of equilibrium will not be where the force due to the positive nucleus: vanishes, but where this force at any electron balances the repulsion due to the other electrons. Therefore the earlier condition cu—*na changes to cu==a7 (n + 8), where 8 is a quantity depending on the repulsion of the electrons and perhaps also on n. The frequency formula now assumes the Rydberg form 1/(m- 8’)? +1/(n+6)?. In the discussion of this expression, Thomson shows that the pro- cesses of ionization and a supposed shrinking toward the center of the outer boundary of the magnetic field account for the exist- ence of a principal series, of the first and second subordinate series, and of the well-known mutual connections between these series such as the Rydberg-Schuster law, common convergence _ frequencies, ete. Doublets and triplets arise from asymmetry, with respect to the nucleus, in the distribution of electrons belonging to the same ring, since this asymmetry would cause r to have slightly different values for the various electrons and hence give rise to different frequencies of vibration. In addition to the topics barely suggested above, the paper contains a wealth of other valuable material for the details of which the reader may be referred to the original text. Two remaining points, however, deserve special notice. By assuming a certain simple relation between the electric and magnetic forces, Thomson deduces Planck’s law. He also calculates the number of waves in a train, after proving that the time taken for the energy lost by radiation to fall to 1/e of its initial value is equal to 10??/5n?. This leads to 4 & 10° waves for the D lines of sodium, and to 660 waves for the characteristic X-rays of the L series of platinum.—Phil. Mag., 37, 419, 1919. He SAuie 4. Absorption of X-Rays—The relative absorption coeffi- cients of X-rays, for a comparatively large number of different elements, have been very thoroughly investigated by T. E. AuREN. The success of the work was largely due to the appli- cation of a compensation method, for which the apparatus was admirably designed, and to the care taken to minimize and cor- rect for small sources of error. The chief results obtained may be summarized as follows: (1) In the chemical compounds examined the additive law has been found to hold unqualifiedly. With the possible exception of carbon, the state of aggregation seemed to ‘ have no influence on the quantity of absorption. The valency of the same element as a constituent of different compounds had no detectable effect on the magnitude of the absorption of the element in question. Chemistry and Physics. 73 (2) The relation between the atomic absorption coefficients of nearly all of the elements from hydrogen to silver (also lead) and the atomic absorption coefficient of copper have been determined at the wave-lengths 0-30, 0-34, 0-36, and 0:38 A. (3) On the assumption that the absorption of hydrogen is due exclusively to scattering produced by the electron combined with the positive nucleus, it has been found that the scattering for other elements is due, in all prob- ability, solely to the electrons constituting the outer layer of the respective atoms. On the basis of the relative atomic absorption coefficient of hydrogen, the number of ‘‘outer electrons’’ has been estimated for the lighter ele- ments. (4) The atomic absorption coefficient increases for different elements nearly proportionally to the atomic number. This fact, taken in conjunction with the interpretation of the atomic number as the number of electrons asso- elated with the positive nucleus, makes it possible to determine the distribution of electrons between the inner and outer regions of the atoms. (5) The number of outer electrons in the lighter elements seems to be constant for the elements placed in the same vertical column of the periodic table. The distribution of electrons thus appears to be closely connected with the periodicity of the chemical properties of the elements as expressed by this system.—Phil. Mag., 37, 165, 1919. Beis: UW. ). Hxperimentelle Untersuchungen wboer die Beugung elek- tromagnetischer Wellen an einem Schirm mit geradlinigem Rande; by Martin SJ6strOmM. Pp. vi, 110. Uppsala, 1917 (Edy. Berling).—This monograph contains a detailed account of an elaborate experimental investigation of the diffraction of short electric waves at the rectilinear edge of a large plane screen. The theoretical object of the work was to test Maxwell’s electromagnetic equations on a special case which is susceptible of rigorous mathematical formulation and which is very exact- ing, if not crucial, with respect to the original equations. The theory of the diffraction field corresponding to a point source and an infinite sereen, the straight edge of which is parallel to the direction of vibration of the linear oscillator, has been worked out exactly on the basis of Maxwell’s equations by C. W. Oseen. Accordingly Sjostrom designed his apparatus to con- form as closely as possible to Oseen’s hypotheses. By using Short electric waves the experimenter was able to explore the complicated parts of the field very close (down to one quarter of a wave-length) to the edge of the screen, a scientific feat which q4 Scientific Intelligence. is not feasible in the case of ordinary light because of the extremely short wave-lengths of visible radiations. A few facts about the apparatus merit attention. The linear oscillator consisted in a spark gap 0-46 mm. long. The sparks passed in a stream of hydrogen gas which was saturated with alcohol vapor. The resonator was provided with a detector of new form, the details of which are partially withheld because of certain patent rights. Its success, however, seems to depend primarily upon the use of a crystal of molybdenum-glanece. The waves emitted by the oscillator had a length of 40 ems. and a logarithmic decrement of about 0:6. The vibrations of the reso- nator were strongly damped (1:2). Both the oscillator and the resonator were kept at a distance of five wave-lengths (200 ems.) above the floor. The screen consisted of a zine sheet 0-4 mm. thick, the other dimensions being 290 and 300 ems. The dif- fracting edge was vertical so that all explorations were made in _ the equatorial plane of the vertical oscillator. After applying small corrections, necessitated by the presence of slight unavoidable disturbing influences, the intensities obtained experimentally agreed with the values calculated from Oseen’s analysis, well within the limits of observational error. The monograph closes with a two-page chart of the loci of con- stant intensity. This map is very instructive since its contour lines bring out the intensity hills and valleys very strikingly, and as it illustrates the parallel case in optics. The investigation brought to light a new phenomenon which is consistent with Oseen’s theory so far as the calculations have as yet been carried. It is this, the intensity of the diffraction field as obtained with Hertzian waves fluctuates within the geometrical shadow of the sereen instead of falling off gradually and smoothly as it, does in the case of ordinary light. The existence of this phenomenon was carefully verified and especial pains were taken by the author to prove that the result is not spurious. Hey Saas 6. On the Mechanical Theory of the Vibrations of Bowed Strings and of Musical Instruments of the Violin Family, with Experimental Verification of the Results: Part I; by C. V. RAMAN. Pp. iii, 158; 28 figures and 26 plates. Calcutta, 1918 (Bulletin No. 15. The Indian Association for the Cultivation of Science).—This monograph (which does not include all of Part I) is a very valuable contribution to the subject because purely empirical results have been eliminated by giving full mathematical explanations of all of the phenomena, from the simplest to the most complex, produced experimentally. ‘‘Not only does the theory succeed in explaining all the known phe- nomena but it has also justified itself by predicting many new relations and results which have been tested experimentally.’’ It is not possible to give an adequate idea of the scope of the investigation in a brief notice. Attention should be called, how- Chemistry and Physics. T5 ever, to the following points. The differential equations and the experimental curves take into account the mutual inter- actions of the belly, the bow, the bridge, and the string of the instrument. Thus the forcing of the bow coupled with the yield- ing of the bridge are subjected to analysis. The wolf-note pitch of the ’cello is given special attention and simultaneous curves are presented showing cyclical alternations in amplitude. The kinematical theory of the motion of bowed strings is discussed, and it is shown that when the bowed point is assumed to divide the string in an irrational ratio, the mode of vibration approaches one or other of certain ideal types which are com- pletely defined by the motion of one, two, or more equal discon- tinuous changes of velocity moving along the string. In the. detailed discussion of these ‘‘irrational’’ modes of vibration the remarkable result is obtained that if n, the number of discontinu- ities, be a prime mteger greater than unity, a two-step zigzag motion is always possible at the bowed point except when this is at or near an end of the string: whereas, if m be not a prime integer, the motion at the bowed point is necessarily of a more complicated type if it lies outside certain sections of the string. Not only is the subject presented in a lucid, rigorous and thorough manner but the reproductions of the photographs of the curves are beautiful from the esthetic as well as from the scientific point of view. H. Ss. U. EE" Guoroey: 1. Umited States Geological Survey; Guorce Otis SMITH, Director.—Recent publications of the U. 8. Geological Survey are noted in the following list (continued from vols. 45, pp. 475, 476; 47, pp. 141, 142): TopocrRaPHic ATLAS.—Thirty-nine sheets. Foutos.—No. 208 Colchester-Macomb Folio, Illinois; by Henry Hinps. In cooperation with the Geological Survey of Illinois. Pp. 14, 2 pls. of topography, 2 pls. of areal geology, 14 text figs. PROFESSIONAL Papers.—No. 104. The genesis of the ores at Tonopah, Nevada; by E. 8. Bastin and F. B. Lanzy. Pp. 50, 16 pls., 22 text figs. No. 107. Geology and ore deposits of the Tintic mining dis- trict, Utah; by WaupEMAR LINDGREN and G. F. Louesiin, with a historical review by V. C. Hurkzes. Pp. 282, 39 pls., 49 text figs. No. 109. The Canning River region, northern Alaska; by K. de K. Lerrineweuu.' Pp. 251, 35 pls., 33 text figs. No. 110. A Geologic Reconnaissance of the Inyo Range and the eastern slope of the Sierra Nevada, Cal.; by ApoutPH KNoprF, 76 Scientific Intelligence. with a section on the stratigraphy of the Inyo Range, by Epwin Kirk. Pp. 130, 23 pls., 8 text figs. No. 114. Geology and ore deposits of the Yerington district, Nevada; by ApotepH KNopF. Pp. 68, 5 pls., 12 text figs. No. 120. Shorter contributions to general geology. Part F, by D. D. Conpir. Part I by T. D. A. CocKERELL. MINERAL Resources of the United States, 1917. Numerous advance chapters. BULLETINS.—No. 660. Contributions to Economic Geology, 1917. Part I, Metals and nonmetals except fuels; F. L. Ran- somr, E. F. BurcHarp, and H. 8. Gaus, geologists in charge. Pp. 3A pls533 text figs: No. 664. The Nenana Coal Field, Alaska; by G. C. Martin. Pp. 54, 12 pls. including a map of central Alaska and a map of the Nenana coal field; also 10 township plats and coal maps. No. 668. The Nelchina-Susitna region; by THEODORE CHAPIN. Pp. 67, 10 pls., 4 figs. ? No. 676. Some Pliocene and Miocene Foraminifera of the coastal plain of the United States; by J. A. CusHman. Pp. 100, 31 pls. No. 677. Geology and mineral deposits of the Colville Indian Reservation, Washington; by J. T. PARDEE. Pp. 186, 12 pls., 1 text fig. No. 680. A geologic reconnaissance for phosphate and coal in southeastern Idaho and western Wyoming; by A. R. ScHULTZ. Pp. 84, 2 pls. No. 681. The oxidized zine ores of Leadville, Colorado; by G. F. Louenium. Pp. 91, 8 pls., 7 text figs. No. 685. Rélation of landslides and glacial deposits to reser- voir sites in the San Juan Mountains, Colorado; by W. W. AtTwoop. Pp. 38, 8 pls., 17 text figs. No. 686. Structure and oil and gas resources of the Osage Reservation, Oklahoma. Parts A, B, C, D, EH, G. No. 691. Contributions to Economic Geology. 1918. Part II. Mineral Fuels; Davin Wuits, G. H. AsHuEy, and M. R. Camp- BELL, geologists in charge. Several advance chapters. No. 593. The evaporation and concentration of waters asso- ciated with petroleum and natural gas; by R. Van A. Minus and Roger C. Weis. Pp. 104, 4 pls., 5 figs. WATER-SUPPLY Paper.—No. 410, 411. Surface water supply of the United States, 1915. Part X, N. C. Grover, Chief Hydraulic Engineer. The Great Basin. Part XI, Pacific Slope Basins. No. 422. Ground Water in the Animas, Playas, Hachita, and San Luis basins, New Mexico; by A. T. SCHWENNESEN, with analyses of water and soil, by R. F. Harz. Pp. 152, 9 pls., 17 text figs. No. 425. Contributions to the hydrology of the United States. Parts 33, 19: Geology. ra No. 427. Bibliography and Index of the publications of the U. S. Geological Survey relating to ground water; by Oscar EH. Meinzer. Pp. 169, with map in pocket (plate 1). 2. Publications of the U. S. Bureau of Mines; Van H. Man- NING, Director.—Recent publications of the Bureau of Mines are as follows (see earlier, vol. 47, p. 143) : Buuuetins: No. 144. Report of a joint committee appointed from the Bureau of Mines and the U. 8S. Geological Survey by the Secretary of the Interior to study the gold situation. Pp. 84, Ipl.,.d figs. No. 154. Mining and milling of lead and zinc ores in the Mis- souri-Kansas-Oklahoma zine district; by C. A. Wricut. Pp. 134, 17 pls., 18 figs. No. 161. California mining statutes annotated; by J. W. THOMPSON. Pp. 312. No. 166. A preliminary report on the mining districts of Idaho; by THomas Varury, C. A..Wricut, EK. K. Sopser, and D. C. Livineston. Pp. 112, 3 pls., 3 figs. No. 169. Illinois mining statutes annotated ; by J. W. THomp- Son. Pp. 594. No. 170. Extinguishing and preventing oil and gas fires; by C. P. Bowiz. Pp. 48, 19 pls., 4 figs. No. 172. Abstracts of current decisions on mines and mining, reported from January to May, 1918; by J. W. THoMmpPson. Pp. 138. No. 174. Abstracts of current decisions on mines and mining reported from May to September, 1918; by J. W. THompson. Bid a8e. iw No. 177. The decline and ultimate production of oil wells with notes on the valuation of oil properties; by C. H. Beau. Pp. 84, 4 pls., 80 figs. No. 179. Abstracts of current decisions on mines and mining, reported from September to December, 1918; by J. W. THomp- SON. Pp. 166. Also numerous Technical Papers. 3. Lowa Geological Survey; Guorce F. Kay, State Geologist. Bulletin No. 6. The Raptorial Bird of Iowa; by Brrr H. BatuEy. Pp. 238, 93 figs. Des Moines, 1918.—Dr. Bailey, the author of this report, died on June 22, 1917, before it was entirely completed; fortunately, however, his student and co-worker, Miss Clementina Spencer, has been able to edit the work and make it complete for the press. This account of the hawks and owls of the State will be found especially valuable by the farmers and is only one of several practical reports which the Survey has issued (see also vol. 47, p. 239). 4. Vorginia Geological Survey ; THomas L. Watson, Director. Bullet XVIII. The geology and coal resources of Buchanat County; by Henry Hinps. In cooperation with the U. S. 78 Scientific Intelligence. Geological Survey. With a chapter on the Forests of Buchanan County; by W. G. Scowas. Pp. 278, 16 pls., 22 figs. Char- lottesville (University of -Virginia), 1918.—The county here described lies on the southeast border of the central part of the Appalachian coal field and is estimated to contain about 12,000,- 000,000 tons of high-grade, coking, bituminous coal in beds of minable thickness. Eighty per cent of the county is true forest land and it is notable that much of the chesnut has not yet been injured by the fungus blight which has been so disastrous farther north. 5. Geological Survey of Illmois; Frank W. DEWozL#, Chief.—Recent publications include the following: | Bulletin No. 39. The environment of Camp Grant; by Rot- LIN D. SauisBuRY and Haruan H. Barrows. Pp. 75, 2 pls., 25 figs., 4 maps in pocket. Urbana, 1918. Also, of the Cooperative Mining Series, Bulletins 23 and 24. 6. North Carolina Geological and Economic Survey; JOSEPH Hype Prart, State Geologist. Biennial report, 1917-18. Pp. 110. Raleigh, 1918.—Presents the results reached during the past two years with respect to geology and mineralogy, forestry, road work, hydrography, ete. 7. Wuasconsin Geological and Natural History Survey; EH. A. Biree, Director and W. O. Horcuxiss, State Geologist—Bulletin XLVII gives a reconnoissance soil survey of northeastern Wis- consin. It is accompanied by a separate series of soil maps belonging to bulletins XLVII to L. 8. Om Skanes Brachiopodskiffer; by Gustar T. TROoEDSSON. Lunds Univ. Arsskrift, n. f., 15, no. 3, 1918—Following a con- certed plan which might well be adopted by graduate students in American universities, the members of the Geological Field | Club at Lund have set themselves the task of describing the geology of their province (Scania). Under the inspiring guid- ance of the late Dr. Moberg, their energetic professor, various students, among them Segerberg, Olin, Hede, Dr. Hadding, Westergard, Professor Gronwall, and now Troedsson, have pro- duced a succession of valuable memoirs on the stratigraphy and paleontology of the Ordovician and Silurian. The latest contribution describes in detail the stratigraphy and fauna of the Brachiopod shales (Upper Ordovician). Forty-one of the 46 species found had not previously been reported from these beds, and 21 are new. It is of interest to note that while the fauna as a whole is Ordovician, the author regards 5:of the species as prophetic of the Gotlandian, so that even where corals are absent, the late Ordovician contains rec- ognizable Silurian elements. The ontogeny of Dalmanites eucen- trus is described, and proves to be of unusual interest. The two plates present excellent figures of all the species. P, Be Miscellaneous Intelligence. 79 III. MuiscetuaAnrous Scienriric INTELLIGENCE. 1. Hquilibruum and Vertigo; by Issac H. Jonzs, M.A., M.D. Pp. 15, 444. Philadelphia, 1918 (J. B. Lippincott Company, $5.00).—This book, bearing the stamp of approval of the Office of the Surgeon General of the Army of the United States, may be characterized by one quotation from the text; ‘‘It is only in the past few years that the function of the vestibular portion of the labyrinth has been carefully studied, preeminently by the Vienna group of otologists, to whom we are indebted for new methods of testing the internal ear.’’ The book may in fact be regarded as the embodiment of the Vienna doctrine by the chief American apologist of the cult. To the quotation from Jones, one may be permitted to add a quotation from the preface to Huxley’s ‘‘Anatomy of Vertebrated Animals’’: ‘‘I have inten- tionally refrained from burdening the text with references; and, therefore, the reader, while he is justly entitled to hold me responsible for any errors he may detect, will do well to give me no credit for what may seem original, unless his knowledge is such as to render him a competent judge on that head.’’ Hux- ley’s statement might be amplified somewhat to the effect that one should be extremely cautious in accepting the statements in the book as true unless his knowledge is sufficient to render him a competent judge on that head. This caution is the more nec- essary because of the numerous loose and even confusing or inaccurate statements to be found throughout the work. Taking our quotation above as one example, it may be pointed out that Erasmus Darwin and Purkinje, to go no further back, were well acquainted with rotation vertigo, and that the classical statement of its laws is that of Purkinje in 1820. MHitzig worked out the laws of galvanic vertigo in 1871 and brought them into line with the laws of rotation vertigo. Goltz and von Troeltsch were both familiar with the effects of incautious irrigation of the external auditory meatus with hot or cold water in 1870. The classical statement of the function of the vestibular, as distin- guished from the cochlear or auditory, portion of the ear, is due to Alexander Crum Brown, Joseph Breuer and Ernst Mach in the early seventies. Brown’s statement in 1876 of the function of the semicircular canal apparatus—the preception of the change of aspect of the head in space—is as good as any that has been made. The study of the relation of the central nervous system to the reactions to stimulation of or lesions of the vesti- bular portion of the ear has been of more recent date, but a sur- prisingly small amount of fundamental knowledge, compared ae a is known, is due to the otologists of the modern Vienna school. A misstatement of a more serious character is found on page 14. The physiologist and the neuroanatomist recognize that the 80 Scientific Intelligence. otic labyrinth belongs to the proprioceptors, and it is so deeply placed in the bone that it cannot be directly affected by surround- ing objects. Crum Brown’s statement of the function of the labyrinth takes no account of the relation of the individual to surrounding objects, and a little reflection will show that, con- trary to the author’s statement, the vestibular mechanism alone can give no knowledge whatever of the relation of the body to external objects. The relation of the body to external objects is known through the exteroceptive sense organs—the eye, the auditory portion of the ear and the other superficial sense organs. The optimistic prophecy on page 24 ‘‘At the present hour perhaps the most valuable service that the otologist can render to the government is in the Aviation Service’’ has scarcely been justified by performance. I should, however, utter a warning that the failure of the so-called Vienna tests to produce anything of importance does not mean that the internal ear has no relation to the problem of aviation, or that something of value might not accrue from the application of other tests to a problem of a somewhat different nature. The contention of the author that the production of vertigo is dependent upon the integrity of the cerebellum, never resting upon more than a slender basis of fact, has been still further undermined by the observations on gunshot injuries of the cerebellum in the recent war. In this connection it may be mentioned that at least one exception to the statement on page 4, ‘‘nor does the cranial surgeon yet recognize the value of ear examinations in helping him to diagnosticate and locate intracranial lesions’’ is to be found in Cushing’s volume ‘Tumors of the Nervus Acusticus and the Syndrome of the Cere- bello-pontile Angle’’ published a year earlier. Enough has been said to indicate that, on its scientific side at least, the book is scarcely suitable to place in the hands of imma- ture and impressionable students. It is matter for regret that unsettled, to say nothing of unknown, matters are stated in a dogmatic way. It is still more regrettable that the book conveys the impression that it has the approval of the medical service of the army. There are some good plates of the normal gross appearance of the brain and its various divisions, but the illustrations of patho- logical conditions, both gross and microscopic, are much inferior to those in Cushing’s volume. ¥. H. Pie Department of Physiology, Columbia University. OBITUARY. Dr. WituiAM Gitson Fartow, Professor of cryptogamic botany at Harvard University, and since 1895 an associate editor of this Journal, died on Juné 3 in his seventy-fifth year. A notice is deferred until a later number. os “ Pee : : Suppl y House for Scientific “Material. ; ETnaorporated 1890. \ few of our recent. acuiirs in the various : ; See ce - departments: Se biee 53. (liste Collection of adie and Rock- . _ forming Minerals. J-188. Price List of Rocks. - Mineralogy: .J-109. Blowpipe Collections. J-74. Meteor- 5 ites, J-190. Collections. J-197. Fine Specimens. oe Paleontology: J-185. Complete Trilobites. J-115. Collec- tions. J-140. Restorations of Extinct Arthropods. + Entomology: J- 38. Supplies. J-125. Life Histories. - ». .J-198. Live Pupae. Zoology: J-116. Material for Diasaotions J-26. Ceci dee: ~~ tive Osteology. J-94. - Casts of Reptiles, ete. | ‘ z Microscope Slides: J-189. Slides of Parasites. Cat. 32 genre Bie * p HORACE S. ‘UHLER,. or New Haven, oe “Provssson J OSEPH S. AMES, OF LRavcmone ee ST Me a Ss. DILLER, or WasHINGTON. ae Sw eae ‘FOURTH SERIES eX L iyntws HOLE N UM B ER. OXOVIII}. No. 284 AUGUST, 1919. “NEW HAVEN, CONNECTICUT. ees “1919. MOREHOUSE & ‘TAYLOR CO., PRINTERS, 123 TEMPLE STREET. * 3 per year, in advance. ~ $6.40 to countries in the eo ‘ingle numbers 50 cents; No. 271, one dollar.. _ » Post: Office z at New Haven, Conn. -) oy, the Act a = 4 Sy Key for the Delciientas Be odie arisen ies in Thin Sections. et Descriptive Tables for tie Ben adele of ites ion to ie practice, make up the greater portion of this book. The. material has _ condensed as much as is consistent with clearness, and the descriptions eee ‘given in as concise a form as ro 2eraee The “« thumb-index gs Bis! i oe eee ereat value. Sat Ses ~~ ix+542 pages, 6 by 9. With 107 figures, 24 diagrams, and a folding ne et colored plate. Cloth, 85. 00 net. = Pei 2 ’ wi Ry a pe es Determinative Mineralogy; ih Tables. = = Rs With Tables for the Determination of Minerals by Means of Their Ch m yp ee and Physical Characters. Second Edition, Revised. eer tgs . By J. VOLNEY LEWIS; =, eee x ‘ Professor of Geology and Mineralogy in ‘Rutgers Colleze: Sa, This work meets the needs of the geologist and mining engineer, and is also. an excellent text-book for students in deter minative © “mineralogy. — ‘Table ig - giving the physical and chemical properties of 380 minerals are included, pare ss “ranged in such a manner that vunknown minerals may ‘be sclera quickly = and. easily. see SS vii+155 } pages. 94 - 8. 34 double-page tables, 68 figures. Se Cloth, $1:50 net. es ee \ Par as Introduction to the Rarer Elements. S = ; — Fourth Edition, Thoroughly Revised. ERG Ey a5 Ss By PHILIP E. BROWNING, Pu.D., Assistant Professor of Chemistry, cs % Kent Chemical Laboratory, Yale University. i = A convenient handbook in the introductor "y study of this: subject. “Thorough revision of the chapter on Radio-Elements, the addition of a plate showing the - spectra of certain gallium and indium products, and the rearrangement of the == ~*~ section dealing with the rare ear ths, has brought this well EBay e work AR to. Ed. ss date. About 200 experiments are now ineluded. x +280 pages. 6by 9. Colored spectrum chart. Cloth, 2 00. net. ee Microscopical Determination of the Opaque — . Minerals. sites ae aS 4 pee An aid to the Study of Ores. Bh Se a ees i By JOSEPH MURDOCH, Pu.D., Geologist, Secondary Enrichment - as ‘Tnvestigation. : 28 ree Gives a scheme of determination of opaque minerals embracing nearl every species of recognized identity that could be secured from the principa mineral collections of the United States. The directions given are Soe: al easily followed, 2 ee vii+165 pages. 6 by 9. ‘IMustrated. “Cloth, £2 -00 seh i ee a a Send for Free Examination Copies TO- DAY So Se - JOHN WILEY & SONS, Inc. Dept. B.—432 Fourth Avenue, New York Be a tes London: Sarees & Hall, Ltd. Montreal, Can.: -. ¥y ‘Manila. PL a Renouf Publishing Co. etre oe Educati THE AMERICAN JOURNAL OF SCIENCE [FOURTH SERIES. |] sao Art. VII.—The Ternary System CaO-MgO-S10, ; by J. B. Frercuson and H. KH. Merwin. CONTENTS. Introduction. ‘ Previous investigations: Temperature relations and optical properties. General procedure and apparatus. The crystalline phases: Composition, optical properties, etc. Fields of stability. Temperature relations along the boundary lines. The quintuple points. Hl Melting temperatures within the fields. DEAT PARI Discussion of the fields. gonian FST SS Pseudowollastonite, wollastonite, 5CaO.2 fee i0,, diopside. Monticellite solid solutions. Akermanite. | i P J The tridymite-cristobalite inversion. AU The binary systems within the ternary system . Summary. Wa APT INTRODUCTION, 9 SSSteseememuw A number of investigations dealing with one or more of the four oxides, lime, alumina, magnesia and silica, have in recent years been carried out as preliminary steps in the laboratory study of rocks. ‘T'o the results of these investigations which dealt with the three ternary systems, CaO-Al.0.-Si0,, CaO-MgO-Al,O,, MgO-Al,0O,- SiO, and parts of the fourth ternary system, CaO-MgO- SiO., we wish to add the results' of an investigation of the hitherto unknown parts of this last system and also to correlate these results with those previously obtained by others. Since but four ternary systems may be con- structed from the four oxides, this investigation marks the completion of the series of studies of the solidus- liquidus relations in these ternary systems. * A short preliminary summary of these results was published in Proce. Nat. Acad. Sci., 5, 16, 1919. Am. Jour. Sct.—Fourts Series, Vou. XLVITI, No. 284.—Aveust, 1919. 6 . 82. Ferguson and Merwin—The Ternary System. . Previous INVESTIGATIONS. A somewhat brief review of the results of the earlier workers in this field will be given. The component oxides will be considered first. lime, Cad. | The melting point of lme has been determined b Kanolt? as 2570°. Two crystalline modifications, both isometric, appear to exist;? the one found at ordinary temperatures has perfect cubic cleavage and a refractive index of 1:83. In the ternary melts it has always appeared in rounded grains.* : Magnesia (periclase), MgO. Kanolt’ places the melting point of magnesia at 2800°C. Only one crystalline form is known, which is isometric, with perfect cubic cleavage and refractive index® of about 1:737. It has been observed in melts as rounded grains, sharp octahedrons or cuboctahedrons, and skeletal octa- hedrons.‘ Silica, SvO,. The several crystalline forms of silica have been thor- oughly investigated by C. N. Fenner.s Of these only tridymite and cristobalite occur as primary phases in this ternary system. Tvridymite appears as thin plates? or platy aggregates'® having refractive indices’? of a= 1-469, y= 1473." Cristobalite appears as aggregates,’ octahedra and cubes:® a—1:484, y — 1-487.8 It melts at 1710 + 10°C." The sluggish transition between cristo- * J. Wash. Acad. Sei., 3, 315, 1915. * For summary of evidence see J. Wash. Acad. Sci., 5, 567, 1915. *Rankin and Wright, this Journal (4), 39, 1, 1915; Sosman, Hostetter, and Merwin, J. Wash. Acad. Sci., 5, 566, 1915. > J. Wash. Acad. Sei., 3, 315, °1915. °*Shght differences in refractive index indicate solid solution under some conditions. Mallard, Bull. Soc. Min. Fr., found 1-7364; Wright, this Journal (4), 28, 325, found 1-734 + -002; Sommerfeldt, Centralbl. Min. Geol. Pal., 1907, 213, found 1-7350. We have found 1-:7375 for some fused magnesia of optical quality furnished by the Alundum Co. The dispersion of this sample follows: C=1-7335, F = 1.7475. * Definite crystals have been observed during this study. See also Ran- kin and Merwin, J. Am. Chem. Soc., 38, 570, 1916. * This Journal (4), 36, 331, 1913. °N. L. Bowen, this Journal (4), 38, 245, 1914. *G, A. Rankin and F. E. Wright, this Journal (4), 39, 1, 1915. % Fenner ’s values were confirmed by Schaller, when account is taken of the higher values—probably caused by solid solution—observed for this natural material. See note 12 below. 2 J. B. Ferguson and H. E. Merwin, this Journal, 46, 417, 1918. Ferguson and Merwin—The Ternary System. 83 balite and tridymite'® takes place in this system below 1500°C.; for the pure substances Fenner’s value is 1 aOR (Oe S The System lime-magnesia, CaO-MgO. In this system a simple eutectic relation exists. The eutectic composition is CaO 67, MgO 33, and its tempera- ture about 2300°C. The diagram given by Rankin and Merwin" is partially reproduced in fig. 1. The System lime-silica, CaO-Si0,. This system is somewhat more complicated. Four compounds are known to exist. They are the calcium metasilicate, the tricalcium disilicate, the calcium ortho- silicate and the tricalcium silicate. The meta- and ortho- silicates only are stable at their melting points and the tricalcium silicate does not even occur as a primary phase in this binary system. ‘T'wo forms of the metasili- cate, wollastonite and pseudowollastonite are known and also three forms of the orthosilicate. The temperature relations existing in this system are given in fig. 2 which is a corrected reproduction of the major part of the dia- gram given by Rankin and Wright.'® The corrections deal with the melting point of cristobalite and the extent of the metasilicate solid solution. ~The following are the optical properties observed for the phases in this binary system which occur in the ter- nary system. Pseudowollastonite,® aCaO.Si0O,; pseudohexagonal equant grains, polysynthetic twinning common; nearly uniaxial se == 0105: 0== LOU, ys L604: extinction angles small. Wollastomte,* ** BCaO.SiO,; monoclinic, lath-shaped ; cleavage parallel to elongation; «=—-1:616, @ 1-629, y = 1-631, 2E about 70°; extinction parallel, optic plane normal to cleavage lines. —8Ca0.2510,; probably orthorhombic, equant grains; a==)641, y — 1-690; + 2V large. a calcum orthosilicate, 20a0. SiO,, 1s stable from its * This inversion is discussed on page 118 of this paper. “G. A. Rankin and H. EH. Merwin, J. Am. Chem Soc., 38, 568, 1916. ~ This: Journal, 39, 1, 1915. ** For later observations, See PO oly oo. ™ Day, Shepherd, Wright, this Journal 22, 290-291, 1906. 84 Ferguson and Merwin—The Ternary System. ~. Bue. ob, Fic. 1—The binary system CaO-MgO. weight per cent. Fig. 2. 2600 12600 2500 we 2500 is sa oa 2400 2300 d4, OSCE Van 2G0:,510, +Melt / al ae eam A, 2700 2100 5 X ge TE OA ee 2700 S / 2000+ s / | a2G0: 520, +Ca0 2000 N / /900 = ad eee wees cas N | : A 7800 | Ca0'S2O, + CxO 7800 Spe ses : 8 I Dw | 7700 oe ; OY a 7700 ~\_0 G0: SiO Hlelt> |. Sey ~ CES 7600 1500 |Z: 35 | _42@0510, 47500 i) Su z Cad ’.520- 400 ie) 7300 S 7200 S Nay 3G 520, Xe) Fig. 2—The binary system CaO-SiO,. weight per cent. Fig. 3. He : 2g 0'S¢O 900 z 900 790 > Welt 1850 7850 1800 800 1750 750 1700- ~~ ~~~ ‘ MgO 210g 5%, 700 1650 650 1600 600 1550 550 1500 500 dymite +/tg0 SLO, se) ee a AOE 2 FV GS 20.52) Fig. 3.—The binary system MgO-SiO,. weight per cent. Ferguson and Merwin—The Ternary System. 85 melting point to 1420°.15 The grains tend toward pris- matic habit, are characteristically twinned, have + 2V bamsegen—— t= 1), 6 11-720, and -y =A-737 2° 7° B calewm orthostlicate is stable from 1420° to about 675°.15 23 The habit and optical properties are practi- cally the same as for the o-form except that twinning is Beldom present, (a2 4°(17, 71-735) 2 24 In the binary system CaQO-Si0,, the inversion « to @ orthosilicate takes place promptly if the inversion tem- perature is passed through not very rapidly.?? y calcwuum orthosilicate is stable below 675°.22 It has peemaine habit, 4—— 1-642, 6 = 1-640, y = 1-654, + 2V = about 60°.74 The System magnesia-sitlica, MgO-S10,. Two binary compounds occur in this system, the meta- silicate and the orthosilicate. The former is unstable at its melting point, while the latter is stable. The temper- Fig. 4. 7600 ss 7600 1550 Cristobalite + Nelt- 1550 1500 73500 CaO Wg 0: 2 520, + (AE 520, | CaO GO B50 Fic. 4.—The binary system Si0,-CaO.MgO.2Si0,. wt. per cent. ** Rankin and Wright, this Journal, 39, 76, 1915. PrLbidsy ps7. ” Observations during the present study on erystals from various parts of the a orthosilicate field, confirm these data except that 8 is about 0-003 larger, and in some quenches scarcely a twinned grain could be found (see note 22), and the elongation may be either positive or negative. * No accurate measurements of refractive index of this form were made during the present study. * In most if not all of the quenches of the ternary system here considered which contained the a form as a primary phase, the a form has apparently persisted for many months. This is true unless either the criterion of twinning is not sufficient for distinguishing this form; or the inversion is like that of quartz at 575° and leaves no distinguishable optical effects. (See note 20.) * Day, Shepherd and Wright, this Journal, 22, 281, 1906. ** Corrected values (see note 19). 86 Ferguson and Merwin—The Ternary System. ature relations are shown in fig. 3. This is a reproduc tion of the diagram given by Bowen and Andersen?* upon which the melting point of ecristobalite has been cor- rected. The following descriptions of these compounds are given by the same investigators. Clino-enstatite, MgO.S1O,, Monoclinic; polysynthetic twinning after (100) is exceedingly characteristic.*° The plane of the optic axis is normal to (010). The angle y,¢== 22°. Refractive indices: «— 11-6315) — 1-660. 3 Fig. 5. CaO: MgO 2820, +2170 'SxO, GONGO 250, 21g 0-320, Fig. 5—The binary system 2Mg0.S8i0,-CaO.Mg0O.2S8i0.. wt. per cent. Forsterite, 2MgO0.Si0,. «= 1-635,, 6 =1-601,, y= 1-670 ; 2 == 80-16". Optically positive." Partial Studies of Ternary System CaO-MgO-Si0,. Besides these binary systems dealing with the oxides, several systems have been studied which form part of the ternary system itself. (See fig. 5.) The first of these systems is the system CaO.Si0,-Mg0O.Si0,. This system may be divided into two parts, the ternary compound CaO.MgO.2810,, called diopside, representing the point of division. Of the two resultant systems, the system CaO.Mg0.28i0,-MgO.S8i0, has been shown by Bowen to be not a true binary system and will be discussed when our later work is considered. The system CaO.MgO. 2Si0,-CaO.Si0, was first studied by Allen, White, Wright and Larsen?* and their results were interpreted °° N. L. Bowen and Olaf Andersen, this Journal (4), 37, 487, 1914. **In ternary melts with magnesia, twinning may be rare, this J ournal, 45, 302, 1918. a Allen, Wright, and Clement, this Journal, 22, 391, 1996. ** This Journal (4), 27, 1, 1909. Ferguson and Merwin—The Ternary System. 87 by Boeke.*®? The method used was that of heating curves (the quench method has not been perfected) and was searcely adequate. Many curves were obtained which were susceptible of various interpretations. The most probable interpretation was based upon the assumption that the inversion temperature of the wollastonite was #1G.° 6. 5z0, G0 I%g0-25:0, Limit of Solid < Salniion of (3 Cab:520, = Fic. 6.—Partial ternary diagram showing the previously published results. wt. per cent. never raised enough by solid solution to cause the solid solutions to appear as primary phases. The chief optical properties observed for diopside are as follows :°° 7 sleds Oy) ——wl-Of Loy = W694. 5.4 2V == 99°: yn == OOo * Grundlagen der physikalisch-chemischen Petrographie, 182, 1915. * Including new determinations. QS S&S Ferguson and Merwin—The Ternary System. The two systems $i0,-CaO.Mg0O.2Si0, and CaO.Mg0O. 2810,-2Mg0.810, have been studied by Bowen*! as part of the ternary system diopside-forsterite-silica. They show simple eutectics, as may be seen in the diagrams given in figs. 4 and 5. But in his ternary system Bowen found that there existed a complete series of solid solutions having diop- side and clino-enstatite as end members.” Most of these solutions, like clino-enstatite, are unstable at their melt- ing points. The rather complicated relations which obtain as a result of this somewhat unusual condition will not be discussed here but may be found in the orig- inal paper. The concentration relations in these systems in so far as they affect the ternary system CaO-MgO-Si0, are collectively shown on the triangular diagram given in fig. 6 and form the starting point of the present investiga- tion. GENERAL PROCEDURE. The initial step in a research of this character is the preparation of charges of known composition, and for this purpose chemically pure calcium carbonate, magne- sium carbonate and silica were used. The magnesium carbonate was not used directly in this process but was first calcined in a platinum crucible in a Fletcher gas- blast furnace. After the ingredients were weighed out and thoroughly mixed in a mortar, the mixtures were fused in platinum crucibles and then reduced to a fine powder. This process was repeated two or three times to ensure complete homogeneity in the final product. Mixtures which fused completely at temperatures below 1500°C were heated in a platinum-resistance furnace; those melting at higher temperatures, in a Fletcher gas- blast furnace. When possible the compositions were finally prepared as glasses, since this form of material is necessary In many experiments and in addition may be easily tested under the microscope for homogeneity. A few peculiarities were noted during the preparation of the compositions. Those lying within the silica field, unless they rapidly cooled, gave either milky or porce- lain-like glasses. Jn the porcelain-like glasses in which the crystallization was further advanced, ee of 2 This Journal (4), 38, 207, 1914. *° See p. 92. Ferguson and Merwin—The Ternary System. 89 silica could be identified, but in the milky glasses the par- ticles causing the milkiness could not be identified micro- scopically. In the charges very rich in silica this tendency to crystallize was accompanied by a great vis- cosity, so that relatively large crystals of cristobalite, Pic. 1. i | Thermoelemee ~eoN Heavy PlairmunLeads a Lea al getire Eriarged Section AH Clamp a . oy ams N Mddddidid db lM MMM dL rd ald dled Lordi MUR ene? teen fm oe Cerin aity Cee AE © | Asbestos ~ NS SS Platinum eater § WN Hluncdiun Tibe firec Q NN SS Magnesia Powder F eIeEN: VL by GSS EEEET' CLE I IEE \ _ Support Glock Uw Ertarged Frew of B molt Fic. 7.—The quenching apparatus and furnace. (1) The furnace set up; (2) Enlarged views of parts of the quenching apparatus showing the method of insulating leads, etc., and the method of attaching the charge; (3) a longitudinal section of the device used to carry the copper leads by means of which a heavy current could be sent through the platinum leads to which the charge is attached and thus cause the charge to fall by fusing the supporting fine platinum wire. When this operation is to take place, the support block and transite cap are removed and a dish containing mer- cury is inserted beneath the marquardt porcelain tube in order to catch the charge and chill it instantly. 90 Ferguson and Merwin—The Ternary System. once formed, would dissolve but slowly, thus making almost impossible the preparation of homogencous com- positions. Compositions lying within the magnesia field showed a similar tendency to erystallize, and with these also, difficulty was experienced in obtaining homogeneity. Once pr epared, each composition was thoroughly investigated by means of the quenching method. This method consists in holding a small quantity of a given composition (called a ‘‘charge’’) at a given temperature long enough to insure the attainment of equilibrium and then chilling it suddenly without disturbing this equili- brium condition. The charge is wr apped in a small piece of platinum foil 0-01 m.m. ‘thick which is attached to a thermoelement tube in such a manner as to be very near the junction, and is dropped into mercury by fusing the supporting wire by means of an electric current. The details of the method may be found in several of the pre- ceding papers.** The apparatus is shown in fig. 7. A few compositions, thoroughly investigated, served to locate approximately the various boundary lines, and with this information the efficient selection of the subse- quent compositions was an easy task. Most of the charges required from 20 to 30 minutes to reach an equilibri ium condition, but some charges, notably those in the 2CaO.Mg0.2Si0, field and those containing much silica, required a much longer treatment. Charges in which at equilibrium there was no glass, such as those used in the study of the wollastonite solid solutions, were heated for days before samples suitable for microscopic examination could be obtained. The formation of unstable pseudowollastonite crystals at temperatures below but near the inversion temperature took place readily when suitable glasses were crystallized at these temperatures. The inversion of pseudowollastonite to wollastonite does not take place readily and so when charges of wollastonite free from pseudowollastonite were desired, glasses were first crystallized at tempera- tures ranging from 800 to 900°C over long periods of time (15 hours) and this material if free from pseudo- wollastonite (in not more than one-half of the charges was this true) and from glass was then reheated at higher temperatures for some hours in order to let the crystals grow and enable a final selection of material to be made with certainty. *° See this Journal, 39, 1, 1915. Ferguson and Merwin—The Ternary System. 91 Charges within the monticellite (CaO.MgO.Si0,): field, and in the forsterite field near it, crystallized with such rapidity that great difficulty was experienced in quench- ing them. The resorption of magnesia did not occur readily and charges selected for a study of this phenome- non were prepared in such a manner as to prevent the formation of large crystals of magnesia which if formed would not then dissolve in a reasonable time. The microscopic examinations were in part very troublesome. It often happened that the crystalline phases were not only very similar optically but also had nearly the same refractive index as the glass in which they were im- bedded, thus making the positive identification of traces of either almost impossible. THE CRYSTALLINE PHASES. The following crystalline phases** are found in the ter- nary system stable in contact with a suitable melt: 1. Lime, CaO. 2. Periclase, MgO. 3. Cristobalite and tridymite, SiO,. 4. Pseudowollastonite, aCaO.Si0,. 5. 3Ca0.2810,. 6. a2CaO.SiO, and B2Ca0.Si0,. 7. Clino-enstatite, MgO.Si0,. 8. Forsterite, 2MgO.Si0,. 9. Diopside, CaO.MgO.2510,. 11. Akermanite, 2CaO.MgO.2S10,,. 11. 5CaO.2Mg0.6810.,. 12. Monticellite (CaO.MgO.Si0, )—forsterite solid solutions. 13. Wollastonite-diopside solid solutions. 14. Wollastonite-5CaO.2Mg0O.681i0, solid solutions. The significant properties of all of these phases with the exception of the compounds 5CaQ0.2Mg0.6810,, and 2CaO.Mg0.281i0, and the solid solutions of wollastonite, of 5CaO.2M¢0.6S8i0,, and of monticellite, have been given earlier in this paper and only corrections and such addi- tional information as we have obtained will be given here. Pseudowollastonite grows in remarkably large crystals as it forms during the inversion of wollastonite in the ** The general temperature-concentration relations of wollastonite, pseu- dowollastonite and 5CaO.2Mg0.6SiO, will be discussed in detail in a subse- quent paper. 92 Ferguson and Merwin—The Ternary System. solid state, and the characteristic polysynthetic twinning with extinctions of 3° on either side is present. Solid solution represented by about 3 per cent magnesia does not appreciably change its optical properties, except to lower y about -006. Wollastonite: Crystals containnmg the maximum amount of diopside at the high temperatures (about 17 per cent) in solid solution had the following observed optical...properties....a==1-619,,.,. 8 =) 1-631... 2 — 2V = 40°-65°. Mixcrystals of wollastonite and 5CaO. 2M¢g0O.68i0,, and also 2CaO.Mg0O.2Si0,, have optical properties which are intermediate, so far as they have been determined. Crystals in the middle of the latter - series are optically positive with large axial angle. 5Ca0.2Mg90.6Si0,: Irregular, elongated grains, 8 par- allel to elongation; o = 1-621, 6 = 1-02/(;-7—=—1t35.. AV;= anout sO] 2Ca0.Mg0.2810,: Appears in stubby prisms ocecasion- ally have definite octagonal cross-section. Crystals from melts of various compositions have »—1-631 + 002, «== 1-638 + -002. Frequently the crystals did not _ appear unless the melt was considerably undercooled. The relation of this compound to akermanite is discussed later. Monticellite: The erystals of monticellite appeared as equant grains without facets, and only optical and chem- ical relationships have been established between the crys- tals and the natural mineral. The observed values of a were 1-638 to 1-640, of 8 1:646, and of y 1-651 to 1-655; + 2V=—85° to 90°. These were obtained from five quenches at temperatures between 1400° and 1500°, hav- ing compositions ranging from 33 to 37 CaQ, 21 to 28 MgO, and 39 to 42 Si0,. 7 Diopside: The refractive indices of pure diopside were observed as follows: «—1-666, y = 1-695. Diopside-clinoenstatite solid solutions have not been studied further, but in the application of Mallard’s formula to their extinction-angles volume per cent not mol. per cent should have been used.?° LIMITS OF THE FIELDS OF STABILITY. Any charge with a composition in a ternary system similar to the one under investigation may be heated * This Journal (4), 38, 248, 1914. Ferguson and Merwin—The Ternary System. 93 until it contains at equilibrium mere traces of crystalline matter immersed in a liquid. This crystalline material may consist of one, two or three phases. Compositions which under these conditions contain one crystalline phase will form an area; those which contain two crys- talline phases will form a line, and those which contain three such phases will be points on a triangular concen- Fic. 8. ‘Sys Op 6 G0-520, Solid Sol* C20 5 Stg0 —Boundaries arecily cerermined; ---Loundaries obtained by mterpolation; +++,Ua Solid solution. 2 e Composition mvestigated, @® Compounds. Fig. 8.—The triangular concentration diagram giving the compositions investigated and the limits of the fields of stability of the various phases in wt. per cent. tration diagram. The area belonging to any crystalline phase is called its field of stability, and the lines and points just referred to represent the boundaries of the fields. The fields of stability and the compositions of the charges used to determine their limits are shown in fig. 8. Table I presents the results upon which this diagram is based. Yt Ferguson and Merwin—The Ternary System. : TABLE I. Quenches which locate the boundaries of the fields of stability. Time Composition wt. Temp. in Phases present*® Boundary CaO MgO SiO, °C. min. 31 7 62 1343 20 Glass + trace SiO, 15, E 32 6 62 1370 15 Glass + aCaO.Si0, 23 14:5 62:5 13869 20 Glass + trace SiO, 1, 2 25-25 12-5 * 62-25 2350 20 Glass + trace SiO, -++ trace CaO.Mg0O.2S8i0, 28 10 62 1343 20 Glass + trace SiO, -++ trace ; CaO.MgO.28i0, 30 61 1327 15 Glass + CaO.MgO.28i0, 9 8-5 60-5 1327 25 Glass + CaO.Mg0O.2Si0, 13 el 9 60 1: 15 Glass + CaO.Mg0O.28i0, 8 60 1344 30 Glass + aCa0O.SiO, 1340 20 Glass + 5Ca0.2Mg0.6S8i0, + CaO.Mg0O.2S8i0, ey 10 5 1350 20 Glass + 5Ca0.2M¢0.6Si0, trace CaO.Mg0O.28i0, 35 11 54 1355 25 Glass + 5Ca0.2Mg0.6Si0, 32 8 60 1344 30 Glass + aCaO.Si0, 13, 14 1340 180 Glass -+ 5Ca0.2Mg0.6S8i0, + trace CaO.Mg0O.2Si0, 35 11 54 1355 25 Glass + 5Ca0.2Mg0.6Si0, 36 12 52 1368 25 Glass + «Ca0O.Si0, 32 7 61 1330-1335 240 Glass + trace S10, + 6CaO.Si0, + 5CaO0.2Mg0.6Si0, 14, 16 30 20 50 1354 15 No ies + 2Ca0.Mg0O.2S8i0, + CaO.MgO.28i0, 3, 4 1359 20 All nets 32 18 50 1367 15 Glass + 2CaO.Mg0O.2S8i0, 33 16:5 50-5 1366 20 Glass + trace 2CaO.Mg0O.2S8i0, 34 15 51 1361 20 Glass + trace 2CaO.MgO.2S8i0, + meeg trace CaO.Mg0O.2Si0, 36 13 51 1352 15 Glass + trace 2CaO.Mg0O.2Si0, 23 220. 54-50 ASS 20 Glass - CaO.Mg0O.2Si0, 4,5 25 22 53 1388 20 Glass + 2Mg0.Si0, 29 20 51 1367 15 Glass + CaO.MgO.2Si0, 29 21 50 1365 20 Glass + 2Mg0O.Si0, + trace CaO.Mg0O.28i0, Ot. 12 51 1366 15) Glass + trace aCa0.Si0, 13; 6 38 Ta Bal: 1366 25 Glass + trace aCaO.Si0, 38 12 50 1381 25 Glass + 2CaO.Mg0O.2Si0, 42.4. 8-8 48-8 1403 i) Glass + aCaO.Si0, 44 8-5 47-5 1406 20 Glass + trace 2CaO.Mg0O.2Si0, 45 8 47 1409 15 Glass + aCaO.Si0, 47 7 46 1393 30 Glass ++ trace aCaO.SiO, ++ trace 2Ca0.Mg0.2S8i0, 47 8 45 1390 15 Glass + 2CaOMg0O.2Si0, 49 6 45 1379 20 Glass + aCaO. SiO, + trace 2CaO.Mg0O.2Si0, 50 45 1380 60 Glass + 3Ca0.2Si10, 6, D 5 515 3:5 465 1417 10 Glass + trace aCa0.SiO, + trace 3Ca0.2Si0, 50 6 +4 1389 15 Glass +. 2Ca0.Si0, t, € 51 5) 44 1410 15 Glass + 2Ca0.Si0, *° The formulas of the pure compounds will be given to sane the phases, but in many eases the actual phases have not such compositions, being solid solutions and therefore variable in composition. Ferguson and Merwin—The Ternary System. 95 Composition wt. % CaO MgO SiOz 53 49 47 46 45 42 42 39 39-5 36 32 32 33 33 57 37 38 38 38 39 39 34 37 38 40 4+ 31-5 30 29 22 22 22 25 26 24 25 21 22 20 21 22 1) 20 25 23 23 22 21 27 28 30 44 44 44. 44 43 43 43-5 43 42-5 43-5 44 45 46-5 45 43 42 43 42 42 41 42 41 40 42 41 41 40 39 38 30 41-5 42 41 1522 1537 1545 Time in min. 30 15 15 60 20 30 15 20 20 39 15 20 30 30 20 30 20 15 15 60 15 30 15 15 15 15 15 15 15 15 20 20 10 30 30 15 30 15 Phases present*® Boundary Glass +. 2Ca0.Si0, (1 € Glass + trace 2CaO.SiO, + trace 2CaO.MgO.28i0, 7, 8 Glass + 2CaO.Mg0O.2Si0, Glass.+ 2CaO.MgO.28i0, Glass + 2Ca0.Si0, Glass -- 2Ca0.Si0, Glass + 2Ca0.Si0, +- 2CaO.Mg0O.2Si0, Glass Glass - 2CaO.Mg0O.2Si0, Glass + 2Ca0O.Si0, Glass + CaO.MgO.Si0, + 2CaO.Mg0O.28i0, 8, 9 Glass Glass Glass + CaO.MgO.Si0, + 2Ca0.Mg0O.28i0, Glass + CaO.MgO.Si0, Glass + 2Mg¢g0.S8i0, 4,9 Glass + 2Mg0O.Si0, + 2CaO.Mg0O.2S8i0, Glass Glass + 2M¢0.Si0, Beek): Glass + 2Mg0.Si0, Glass + CaO.MgO.Si0, Glass +. CaO.MgO.Si0, Glass + CaO.Mg0O.Si0. 8, 10 ‘Glass + CaO.Mg0.Si0, Glass + CaO.MgO.Si0, Glass + CaO.Mg0O.Si0, + 2CaO.Si0, Glass Glass -+- 2Ca0.Si0, Glass + 2Ca0.Si0, Glass -_ 2Ca0.8i0, Glass + MgO 10, 11 Glass + MgO Glass + MgO 10, 12 Glass + MgO -+| trace 2Ca0.8i0, Glass + trace MgO + trace 2CaO.S10, Glass + MgO + 2Mg0.8i0, 2 EL Glass - 2Mg0.S8i0, Glass + MgO The 62CaO.Si0, field, if such a field exists, is too small to be shown upon the diagram. If no solid solution exists, it consists of that portion of the 2CaO.SiO, field which hes below the isotherm?’ of 1420° since the inver- sion of the 8 form to the « form in the pure compound occurs at this temperature. The points 14 and 16 he too close to the point 15 to be separately located. *" See figure 12, beyond. 96 Ferguson and Merwin—The Ternary System. The limits of the lime field were obtained by interpola- tion. One quench at 1660°C of a charge with a composi- tion lime 55, magnesia 25, silica 20, showed no glass and in it crystals of 2CaO.SiO, and lime could be identified. If an equilibrium condition had been reached this indi- cates a eutectic relation between lime, magnesia and a2CaO.SiO, and this we have assumed to be true in making our diagrams. However, Rankin and Wright found that, in the binary system, lime and siliea first gave rise to 2CaO.SiO, and lime before combining to give 3CaO.SiO,, and a similar condition may have been encountered by us. If a eutectic exists (as we have assumed to be the case) the temperature of it must lie above 1900°C, the decomposition temperature of 3CaO.S8i10.. The heat treatment of charges in which the compound 2CaO.MgO.28i0, occurs as a primary or a secondary phase, as given in Table I, may seem to be far too short a time in view of the tendency shown by solutions of this compound to undereool. Such is, however, not the case, since if care be taken to start with fully crystallized material, and the temperature of the charge be never ~ allowed to exceed the desired temperature, this difficulty can be and was avoided. In studies of this nature the length of the heat treatment of itself means but little unless the properties of the reacting phases are known and these may be of such a character as to necessitate a knowledge of the original state and previous history of each charge before one can judge if the heat treatment has been sufficient. The experiments carried out at temperatures above 1600°C were made in the cascade furnace®® designed for the determination of the melting point of cristobalite. TEMPERATURE RELATIONS ALONG THE BOUNDARY LINES EXCLUSIVE OF QUINTUPLE POINTS. The temperatures at which the complete fusion of the charges with compositions represented by the boundary lines takes place, may be determined either directly upon such charges, or indirectly by following the erystalliza- tion curves of the compositions which lie within the adjacent fields. This latter method offers no especial * J. B. Ferguson and H. E. Merwin, this Journal, 46, 417, 1918. Ferguson and Merwin—The Ternary System. 97 difficulty if solid solutions do not exist and the erystalli- zation lines are straight lines, but if solid solutions exist these lines which represent the changes in the composi- tion of the liquid in a charge during crystallization are eurved, and since their curvature is often difficult to determine, in this case the method may be quite uncertain. In the ternary system under investigation there is much solid solution and for this reason most of the charges which were used for this part of the study lay close to the boundary lines in composition. The experimental results of this study are given in Table II. TABLE II. Quenches which determine the melting temperatures along the boundary lines. Time Composition wt.% Temp. in Phases present Boundary CaO" MeO “SiO, ~C: min. 32 6 62 1361 15 Glass +--+ aCaO.SiO,-+ SiO, 1, 16, 15, E 1370 15 Glass + aCaO.Si0, 1339 15 Glass + aCa0O.Si0, + SiO, 1334 20 Glass + BCaO.Si0, + Si0, 32 i 61 133331 20 Glass + @CaO.Si0, -| SiO, eB 20 Glass + aCa0O.Si0, 31 fee? ais 48 20) Glass! S10; 1338 20 Glass + $10, + aCa0.Si0, 23 14:5 62:5 1370 20 Glass + trace SiO, ale 1365 25 Glass + trace S$i0, + CaO.Mg0.2Si0, 2-25 12-6 62:5) 1352 20 Glass -+- CaO.MgO.Si0, 1350 20 Glass + CaO.Mg0O.2Si0, + SiO, 28 10 62 1349 30 Glass 1338 20 Glass -+- SiO, + CaO.MgO.2Si0, 31 9 60 1326 15 Glass + CaO.MgO.2Si0, I, & al 15 Glass + CaO.MgO.2810, + 5Ca0.2Mg¢0.6S8i10, 32 8 60 1340 20 Glass + trace CaO.MgO.28i0, + trace 5CaO.2Mg0.6Si0, 33 10 57 1352 30 Glass 1350 20 Glass + 5CaO. 2Mg0.6S810, + CaO.Mg¢0O.28i0, 355 11 54 13538 20 Glass + 5Ca0.2Mg0.6Si0, + CaO.MgO.28i0, 1356 25 Glass + 5Ca0.2Mg0.6Si0, 38 11 51 1361 30 Glass + (trace aCaO.Si0,) * 5Ca0.2Mg0.6Si0, + trace CaO.MgO.28i0, 1, 3 36 12 52 1368 25 Glass + aCa0O.Si0, 13; 14, 15 1363 25 Glass + aCaO.Si0, + 5Ca0.2M¢g0.6Si0, 32 8 60 1344 Glass + aCa0O.Si0, 36 12 52 1368 Glass + aCa0O.Si0, (See also quenches 1, 3 above) * gCaO.SiO, is here unstable. Am. Jour. Sct.—FourtH SERIES, VoL. XLVIII, No. 284.—Aveust, 1919. ti Lo 98 Composition wt.% Temp. Ferguson and Merwin—The Ternary System. CaO MgO SiO, 32 30 34 23 25 26 29 50 44 45 18 16-5 8-5 “I ~ 20-5 50 50-5 51 54-5 47 46 44 44 43 43-5 43-5 “On 1365 1371 1367 1364 1361 1383 1379 1383 1388 1375 1380 1365 1384 1378 1410 1417 1404 1410 1430 1367 1362 1375 1381 1403 1398 1402 1406 1409 1403 1393 1405 1410 1422 1440 1432 1448 1453 1445 1438 Time in min. 20 20 20 20 20 20 20 20 20 20 20 20 20 20 10 10 15 15 15 15 15 25 25 15 15 20 15 15 Phases present Glass + CaO.Mg0O.28i0, + 2CaO.MgO.2Si0, Glass + 2Ca0.MgO.2Si0, Glass +. 2CaO.MgO.2Si0, Glass + 2CaO.Mg0O.2Si0, +- CaO.Mg0.2S8i0, Glass + trace 2CaO.Mg0O.2Si0, + trace CaO.MgO.28i0, Glass + CaO.Mg0O.28i0, No glass Glass + trace CaO.Mg0O.28i0, + 2Mg0.8i0, Glass + 2Mg0.Si0, Glass + 2Mg0.Si0, + CaO.Mg0O.28i0, Glass + 2Mg0O.S8i0, Glass + 2Mg0.Si0, + trace CaO.Mg0O.28i0, Glass + 3Ca0.2Si0, Glass + 3Ca0.2Si0, + Glass + trace crystals Glass + 2Ca0.Si0, + 3CaO.2Si0, Glass +-2Ca0.Si0, Glass + 2Ca0O.Si0, + trace 3CaO.2Si0, Glass + aCa0.Si0, Glass + aCaO.Si0, + 2Ca0.MgO.2S8i0, Glass + aCa0.Si0, + 2CaO.Mg0.2Si0, Glass + 2CaO.MgO.2Si0, Glass + aCa0O.Si0, Glass + aCaO.Si0, + 2CaO.MgO.2Si0, Glass + aCa0O.Si0, + 2CaO.Mg0O.2Si0, Glass + 2CaO.Mg0O.2Si0, Glass + aCa0O.Si0, Glass + aCaO.Si0, + 2CaO.Mg0O.2810, Glass + trace aCaO.SiO, + trace 2CaO.MgO.2Si0, Glass + 2CaO.Si0, + 2Ca0.Mg0O.28i0, Glass Glass + 2Ca0O.S8i0, -+ trace 2CaO.MgO.2Si0, Glass + 2Ca0O.Si0, Glass + 2Ca0.S8i0, + 2CaO.Mg0O.2Si0, Glass + 2Ca0.S8i0, + 2CaO.Mg0O.2Si0, Glass : Glass Glass + 2CaO.MgO.2Si0, + CaO.Mg0O.Si0, Boundary 3, 4 aCaO.Si0, Glass + aCa0O.Si0, + 3Ca0.2Si0, > 3, 13, 6 Ferguson and Merwin—The Ternary System. 99 Time Composition wt.% Temp. in Phases present Boundary CaO MgO SiO, nO. min. : 34 22 44 1445 30 Glass 859 1442 30 Glass + 2CaO.MgO.2Si0, +- . ier CaO.Mg0O.Si0, 39 18 43 1444 20 Glass + 2Ca0.Mg0.2Si0, 1429 90 No 2Ca0.Si0, 38 20 42 1436 20 No 2Ca0.Si0, 33 22 45 1432 20 Glass 4,9 1428 15 Glass + 2Mg0.Si0, 2CaO.Mg0.2Si0, 32 23 45 1430 20 Glass + 2Mg0.Si0, y 1423 15 Glass + 2Mg0.SiO, + 2CaO.MgO.2Si0, 31-5 22 46-5 1410 30 Glass + 2Mg0.Si0, 1406 25 Glass + 2Mg0.Si0, + 2CaO.Mg0O.2Si0, 30 22 48 1415 20 Glass + 2Mg0.Si0, 1392 30 Glass + 2Mg0.Si0, + trace 2CaO.MgO.2Si0, 34 25 41 1502 30 Glass + MgO + CaO.MgO.SiO, 10, 11 1510 20 Glass + MgO 35 25 40 1511 atte Glass + MgO + CaO.Mg0O.Si0, 1516 15 Glass - MgO 38 21 4] 1489 15 Glass + 2Ca0.Si0, + CaO.MgO.Si0O, 8, 10 1493 15 Glass 40 22 38 1537 30 Glass + MgO - trace 2Ca0.Si0, 10, 12 44 21 35 1660 15 Glass + MgO + 2Ca0.Si0, 7 G90 30 Glass + trace MgO + trace 2CaO.Si0, Bie 27 41-5 1529 20 Glass ay oe 1522 15 Glass + MgO + 2Mg0.Si0, The similarity between the optical properties of the monticellite crystals which contain in solution some for- sterite and the forsterite crystals themselves is very marked, and for this reason the melting temperatures along the boundary line 9,11 in fig. 8 could not be deter- mined except by the slope of the liquidus of the adjacent fields. THE QUINTUPLE POINTS. Fourteen quintuple or invariant points at which three crystalline phases and a liquid can co-exist are to be found in this ternary system, and of these, six are true eutectics. These quintuple points are the points of inter- section of three boundary lines and when the tempera- tures along each of three lines fall as they approach the point of intersection the point is called a eutectic. Point 1, fig. 8, is a eutectic between diopside, tridy- 100 Ferguson and Merwin—The Ternary System. mite, and 5CaO0.2Mg0.6Si0,. It has a composition CaO 30-6, MgO 8, SiO, 61:4, and a temperature LSZOREsoAC: TABLE III. Quenches which determine the temperature relations at point 1. Time Composition wt. Z Temp. in Phases present CaO MgO SiO. EC: min. 31 7 62 1324 20 Glass + erystals 1319 45 No glass 31 9 60 1321 15 Glass + crystals 1316 15 No glass 32 7 61 1319 20 No glass 1324 25 Glass + erystals 32 8 60 1315 20 No glass 1320 20 Glass + erystals Point 16 is a non-eutectic at which tridymite, a wollas- tonite solid solution, and a 5CaO.2M¢0.6Si0, solid solu- tion can co-exist with a liquid.. The temperature and location of this point have not been separately deter- mined. It hes very close to point 15 with a probable temperature of 13830 + 5°C. Point 15 is a non-eutectic between pseudowollastonite, a wollastonite solid solution and tridymite. It occurs at the composition CaO 31:3, MgO 7-2, SiO, 61-5, and its temperature is 1335 + 5°C. TABLE IV. Quenches which determine the temperature relations at point 15. Time Composition wt.% Temp. in Phases present CaO MgO SiO, SC peur Bil a 62 1343 20 Glass + SiO, 1338 20 Glass + SiO, + aCa0O.Si0, 32 6 62 1339 20 Glass -- SiO, + aCaO.Si0, 1334 20 Glass + Si0, + (8Ca0.Si0, or : 5Ca0.2M¢0.6Si0.) By i 61 IB BIb 20 Glass + S10, + (8Ca0.Si0, or 5CaO.2M¢0.6Si0.,) 1337 20 Glass + aCa0O.S8i0, Point 14°° is a quintuple point between pseudowollas- tonite, a wollastonite solid solution, and a 5CaO.2Me¢0. 6810, solid solution. It has a composition CaO 31-4, MgO 7:6, SiO, 61, and a temperature of 1340 + 5°C. Point 13 is a quintuple point between pseudowollaston- *® The location and temperatures of points 14 and 13 will be discussed under the wollastonite and 5CaO.2Mg¢g0.6Si0, solid solutions. Ferguson and Merwin—The Ternary System. 101 ite, 90aO.2Mg0.68i0,, and 2CaO.Mg0.2Si0,. The com- position i is CaO 36-7, MgO 12-3, SiO, 51, and the Loma ena Mire tooo == 0 -C. TABLE V. Quenches which indicate the temperature relations at point 13. Time Compositionwt.% Temp. in Phases present CaO MgO SiO, aC min, 36 12 52 1368 25 Glass + aCaO.Si0, 1363 25 Glass + «Ca0O.8i0, + 5Ca0.2Mg0.6Si0, 38 in 51 1366 25 - Glass + qCaO.Si0, + 5Ca0.2Mg¢0.68i0, 37 12 51 1366 15 Glass + «Ca0O.Si0, 38 12 50 LES 27 Glass + aCaO. SiO, + 2Ca0.Mg0.28i0, Point 3 is a eutectic between «dCaO.2M¢0.6Si0, solid solution, diopside and 2CaO.Mg0O.2Si0,. Its composi- tion is CaO 36, MgO 12-6, Si0, 51:4, and its temperature dO O°C, TABLE VI. Quenches which determine the temperature relations at point 3. Time Composition wt.% Temp. in Phases present CaO MgO SiO, °C, min. 36 13 51 1345 30 No glass 1350 30 Glass +5Ca0.2Mg0.6Si0, + CaO.Mg0O.2Si0, + 2CaO.Mg0.2Si0, 1354 120 Glass + crystals 1348 120 Crystals + merest trace if any of glass 37 12 51 1351 20 All erystals 1353 30 Glass + crystals Point 4 is a eutectic between 2CaO.MgO.2Si0., forster- ite and diopside. The composition is CaO 29-8, MgO 20-2, SiO, 50, and the temperature 1357 + 95°C. TABLE VII. Quenches which determine the temperature relations at point 4. Time Composition wt. % Temp. in Phases present CaO MgO SiO. eae AO min. 29 21 50 1354 30 No glass : 1359 20 Glass + erystals 30 20 50 1354 15 No glass 1359 20 All glass Point 6 is a eutectic between pseudowollastonite, 3CaO. 2810, and 2CaO.Mg0O.2S8i0,. Its composition is CaO 49-2, MgO 6:3, SiO, 44-5, and its temperature 1377 + 5°C. 102 Ferguson and Merwin—The Ternary System. TABLE VIII. Quenches which determine the temperature relations at point 6. Time . Composition wt. Z% Temp. in Phases present CaO MgO SiOz °C. min. 49 6 45 1374 20 No glass 1379 20 Glass + erystals 50 5) 45 1378 20 Glass + erystals 1374 20 No glass 49 i 44 1375 15 No glass 1384 15 Glass + erystals Point 7 is a quintuple point between 82CaO.S10,, 3Ca0O. 28i0, and 2CaO.MgO.2Si0,. The composition is CaQ 49-5, MgO 6-2, SiO, 44-3, and the temperature is NBS Se HG. | TABLE IX. Quenches which determine the temperature relations at point 7. Time Composition wt.% Temp. in Phases present CaO MgO SiO, AO; min. 49 7 44 1384 15 Glass + 3Ca0.2Si0, + 2CaO.Mg0O.2Si0, 1389 15 Glass + 2Ca0O.S8i0, + 2CaO.MgO.2Si0, 50 6 44 1391 15 Glass + 2Ca0O.Si0, + 3Ca0.28i0, 1384 15 Glass + 2CaO.MgO.2Si0, + 3Ca0.2Si0, Point 8 is a eutectic between 2CaO.MgO.28i10., «2CaO. SiO, and a monticellite solid solution. Its composition is CaO 39, MgO 18-3, SiO, 42:7, and its temperature NO se O)Or TABLE X. Quenches which determine the temperature relations at point 8. Time Composition wt.% Temp. in Phases present CaO MgO SiO. ‘C. min. 39 19 42 1443 20 Glass +- erystals 1436 20 No glass 1443 60 Glass + erystals 1438 45 No glass, crystals including 2CaO.Si0, 39-5 18 42-5 1443 30 Glass + crystals 1438 20 Glass + erystals 1432 15 No glass, erystals including 2Ca0.Si0, Point 9 is a quintuple point between 2CaO.MgO.2Si0,, forsterite, and a monticellite solid solution. Its compo- sition is CaO 33-3, MgO 22:3, SiO, 44-4, and its tempera- ture tag a= 5 2c: Ferguson and Merwin—The Ternary System. 103 TABLE XI. Quenches which determine the temperature relations at point 9. Time Compositionwt.% Temp. in Phases present CaO MgO SiO, Ae min. 33 24 43 1439 20 Glass 2Mg0.Si0, + CaO.MgO.Si0, + No 2Ca0.MgO.2Si0, 1434 20 Glass-+ 2Ca0.MgO.2Si0, + 2Mg0.SiO, 34 22 44 1439 30 Glass 2Ca0.MgO.28i0, ++ CaO.MgO.Si0, 1434 35 Glass + 2CaO.MgO.28i0, + 2MgO.Si0, Point 10 is a quintuple point between periclase, a mon- ticellite solid solution and «2CaO.Si0,. It has a compo- sition CaO 37:3, MgO 22-3, SiO, 40-3, and a temperature 1498 =. 5°. TABLE XII. Quenches which determine the temperature relations at point 10 Time Composition wt.% Temp. in Phases present CaO MgO SiO, OP min, BU De 40 1494 20 Glass + 2Ca0.Si0, + CaO.MgO.Si0, 1500 25 Glass + trace MgO + CaO.MgO.Si0, 38 22 40 1503 10 Glass + MgO + 2CaO.Si0, 1498 20 Glass + 2CaO.Si0, + CaO.MgO.Si0, Point 11 is a quintuple point between periclase, forster- ite and a monticellite solid solution. Its composition is CaO 32:1, MgO 26-4, SiO, 41-5, and its temperature 1502 255°C. TABLE XIII. Quenches which determine the temperature relations at point 11. Time Composition wt.% Temp. in Phases present CaO MgO SiO, °C. min. 31-5 27 41-5 1499 25 Glass + 2Mg0.Si0, + CaO.Mg0.Si0, + No MgO 1507 25 Glass + MgO ++ 2Mg0.Si0, 32 26 42 1496 15 Glass + 2Mg0.S10, + CaO.Mg0O.Si0, 30 28 42 1500 25 No MgO -+ ? 1508 15 MgO-+ ? Point 12 is a eutectic*® between periclase, lime and a2CaO.SiO,. Its composition and temperature are uncer- tain since the latter lies above the working temperatures of either of our furnaces and the rapidity with which a20aQ.SiO, and periclase both crystallize precluded the * See the discussion of the lime field following Table I. 104 Ferguson and Merwin—The Ternary System. use of the iridium furnace, but the temperature probably lies above 1900°C, the temperature at which the trical- cium silicate decomposes into lime and «2CaO.Si0,. The exact temperature relations at the quintuple points, at the quadruple points on the side lines, and along the boundary lines, may be depicted by constructing a model which has as a base the concentration diagram, fig. 8, and upon which the temperatures are shown as vertical dis- ipng, O, Fic. 9.—A model constructed by plotting vertically upon the concentra- tion diagram as given in fig. 8, the temperature of complete fusion of the compositions lying along the boundaries of the fields of stability of the various phases. tances above this base. Fig. 9 is a photograph of such amodel.* This particular model includes and correlates the previous results of Bowen on this ternary system, “ This is the framework of a solid model. A description of the construc- tional details of such a model is given by Rankin and Wright, this Journal, Soe 1 oN: 105 Ferguson and Merwin—The Ternary System. 00OL ool 002t o0gs 00ul 004! 009%. OOLt 008! SOUT] OST} SuoTV SUOT}VIEI 91n}V19dUI9} OY} O}VOTPUL YOY 6G “Sy UL UMOYS Sour, ABpuNnog eyy Fo suotooford [BOl}10A OU T.— POT “DIL OrSZ:051 OFZ SO -O8WZ OPTS G2: 0092 O1S-077” 0°S: 072 0752 OL 092 “OFS 2 ODL “0°52: 05S 02) 2 "DOL YI 70rC10M2Z? ODL 000t oot 004/ 00¢¢ 0064 00% OOLt 008/ 106 Ferguson and Merwin—The Ternary System. OO0O/ OOM 002 00ff 000 004 00H OO0L! 008/ ‘SOUT, OSOT} SuoTe SuUOTYv[eI 91nyVsdduI} VY} 9}VOTIPUL YOryM G6 “SY ur UMOYS Sout, Arepunod oyy Jo suorzoofoad [Vory10A OY— OT “OT Q0T “OL ‘orc. 04/2 o1cz040M 000 oo 002! 008! 00u 005 00 00u/ 008! KOK Ferguson and Merwin—The Ternary System. 0001 Oot 002 00st 00d 009 009/ OOL 008/ “SOUT, VSO SUOCTe SuUOTLIEL 91nzye1oduie} BY} 9}VOIPUL YOIYM G “Sy UL UMOYS Sour, Arepunog oy} Jo suotyooload [eo410A OY J— INT “D1 7075-04-02) “0152: 0-02 707512 04/0”) “01m O0L VIA Oe OSG: O8WZODS OSGOWLZLOVS “07S 07° O1S:02) © 015.9%) ‘b1¢704,/-09) O15 9:O9LL2:0°9¢ OO o0ogs 00 004nt 009/ 00Lt 00H 108 Ferguson and Merwin—The Ternary System. with our results given in Tables II—XITI, inclusive, in addition to the results of the various investigators on the side-line binary systems. A vertical projection of IIe ILI Fig. 11.—The complete temperature concentration diagram which was constructed by plotting vertically upon the concentration diagram given in fig. 8 the temperatures of complete fusion of the various compositions. each of the lines within the ternary system is given in figs. 10 (a, b and c), and perhaps shows these relations more clearly than does the model itself. These curves are also of interest because they serve as Ferguson and Merwin—The Ternary System. 109 a check upon the experimental methods employed. The curves 1F and 4G are perhaps the best illustrations of what reliance may be placed upon the methods. Each of these curves represents the work of several investi- ING, We 520, GOSGO-25u' AY CANE yf 2(Ca0-1g0 2510, 1958 1g 1436 : —Bounaaries, —lsotherms determined, —-—/sotherms by ertrapolation; © Compounds +++.ZQ Solid solutions . Fie. 12.—A concentration diagram somewhat similar to that given in fig. 8 upon which the isotherms showing the temperatures of complete melting of the various compositions are drawn. The diagram is on a wt. per cent basis. . . gators; 2, F, and 5, G were determined by N. L. Bowen, 1, 2, and 4, 5, by ourselves. The agreement here obtained is of the order usually found between experiments of the Same series, but in this case somewhat exceeds that usually obtained by us when the identical apparatus was not used for all experiments. A somewhat similar 110 Ferguson and Merwin—The Ternary System. agreement was found between the concentration relations, and this fact may readily be gleaned from an inspection of figs. 6 and 8. A maximum is shown on the line 8, 9, although it has not been experimentally determined, the line 8, 9 being HGS. SiO, 1710 Cristobakte 2C20-520, S 27350 5 CO Jg0 2570 — Sounaares. —ssotherms aetermined; —-—lsotherms by extrapolation; © Compounds ; 2800 +++,G@Z Sokd solutions. Fic. 13.—A similar diagram to that shown in 12 except that it is on a mol. per cent basis. With this exception this paper has been written upon a wt. per cent basis. too flat. The reasons for placing a maximum here will be discussed under the monticellite solid solutions, and similarly the peculiar relations exhibited by the lines 1, 3 and 13, 14, 15 will be discussed under the wollastonite solutions. Ferguson and Merwin—The Ternary System. 111 THe Meuting TEMPERATURES WITHIN THE FYELDS. The temperatures at which charges with compositions lying within the fields become completely fused are given in Tables XI V—XXI, inclusive. TABLE XIV. Melting temperatures in the silica field: Melting point of cristobalite IO OSC: Time Composition wt. % Temp. in Phases present CaO MgO SiOz °C. min. 23 7 70 1675 120 Glass previous charge reheated 1638 30 Glass + erystals 23 14-5 62-5 1375 20 Glass + trace crystals 25 10 65 1485 45 Glass 1472 15 Glass + trace crystals 26 7 67 1546 10 Glass 1536 10 Glass + crystals 30 5 65 1463 15 Glass + erystals 1472 10 Glass 31 ih 62 1347 20 Glass 1343 20 Glass + trace crystals TABLE XV. Melting temperatures in the diopside field; melting point of diopside 1391°C. | Time Composition wt. % Temp. in Phases present CaO MgO SiO. eC: min, 28 13 59 1375 10 Glass 1370 10 Glass + erystals 30 15 ZOO ee Sie 15 Glass + erystals 1381 10 Glass The melting temperatures of compositions lying within the fields of the @CaO.Si0, or wollastonite solid solu- tions and the 5CaO.2Mg0.6S810, solid solutions must be obtained from the temperatures of the boundaries, as the fields are too narrow to warrant an investigation. TABLE XVI. Melting temperatures in the aCaO.Si0, field; melting point of aCaO.Si0, 1540°C. Time Composition wt. % Temp. in Phases present CaO MgO Sid. nC: min. 32 6 62 1370 15 Glass + trace crystals 35 5 60 1402 10 Glass 1395 10 Glass + erystals 40 5) 5d 1468 10 Glass + trace crystals 112. Ferguson and Merwin—The Ternary System. Time Composition wt. Z Temp. in Phases present CaO MgO SiO, Aor min. 45 5 50 1476 10 Glass 1468 15 Glass + erystals 46.7 3-1 50-2 1490 15 Crystals + trace glass? 1500 15 Glass 44.3 2-8 52-4 1500 15 Trace glass + erystals 1510 15 Glass + trace crystals 44 6 50 1470 15 Glass + trace crysals TABLE XVII. Melting temperatures in the 2CaO.MgO.2Si0, field; melting point of 2CaO.Mg0O.2S8i0, 1458 + 5°C. Time . Composition wt. 7% Temp. in Phases present CaO MgO Si02 ae: min. 35 20 45 1446 10 Glass 1440 10 Glass + crystals 39 14 47 1431 20 Glass + trace crystals 39 15-5 45-5 1440 10 Glass + crystals 1445 10 Glass 39 17 44 1449 20 Glass + crystals 1454 20 Glass 39 18 43 1450 - 20 Glass 1444 20 Glass + erystals 40-33 14-66 45 1455 5 Glass 1450 10 Glass + crystals 4] 13 46 1434 20 Glass 1430 20 Glass +L erystals 1459 20 Glass 41 15 44) 1456 15 Crystals only 2CaO.MgO.28i0, § 1460 | 10 Glass 1455 10 Crystals only The phase 3CaO.2Si0, is unstable at its melting point and its field is too small to warrant the determination of melting temperatures within it, other than by interpola- tion from the boundaries. The phase a2CaQ.Si0, melts at 2130 + 10°C and the temperature gradient within its field is so steep that but few melting temperatures were determined. TABLE XVIII. Melting temperatures within the 2CaO.Si0, field. Melting point of a2CaO.Si0, 2130 + 10°C. Time Composition wt. % Temp. in Phases present CaO MgO SiO. °C. min. 48 10 42 - 1547 10 Glass + trace crystals 45 12 43 1470 15 Glass + erystals 1475 15 Glass 40 20 40 1546 10 Glass 1536 10 Glass + crystals Ferguson and Merwin—The Ternary System. 118 The phase CaO.MgO.SiO, is unstable at its melting point and in addition is variable in composition since it belongs to a series of solid solutions of forsterite in pure monticellite. TABLE XIX. Melting temperatures within the monticellite field. Time Composition wt. % Temp. in Phases present CaO MgO Si02 °C. min. 30 25 42 1502 16 Glass + erystals 1509 16 Glass 39 22 43 1478 15 Glass 1473 15 Glass + crystals 37 21 42 1483 15 Glass 1467 15 Glass + crystals at 22 41 1497 15 Glass 1487 15 Glass + crystals 38 20 42 1489 18 Glass 1483 15 Glass +_ crystals TABLE XX. Melting temperatures within the periclase field, the melting point of periclase 2800 + 20°C. Time Composition wt. Z - Temp. in Phases present CaO MgO SiO, Gls min. 34 25 4] 1515 20 Glass + trace MgO 35 25 40 1539 10 Glass 1528 10 Glass + crystals 37 23 40 1521 20 Glass 1517 20 Glass + crystals TABLE XXI. Melting temperatures within the forsterite field, the melting point of ' forsterite 1890°C. Time Composition wt. % Temp. in Phase presented CaO MgO SiO. nee min, 24 24 52 1432 10 Glass 1426 10 Glass + trace crystals 23 28 49 1528 10 Glass + trace crystals 27 26 47 1501 15 Glass + crystals 1509 15 Glass 28 24 48 1460 10 Glass + erystals 1468 10 Glass 30, 25 45 1490 15 Glass 1485 15 Glass + crystals 32 23 45 1459 15 Glass 1445 20 Glass + crystals 32 25 43 1498 15 Glass + trace crystals 32 26 42 1506 20 Glass + crystals 1510 20 Glass Am. Jour. Sct.—Fourts Series, Vou. XLVIII, No. 284.—Aveust, 1919. 8 114 Ferguson and Merwin—The Ternary System. The liquidus-solidus temperature relations have now, as far as possible, been determined over the entire ternary system and they may be represented by a solid model constructed by properly filling in the model shown in fig. 9. A photograph of this solid model is shown in fig. 11. These relations may also be indicated by means of a tri- angular concentration diagram similar to the one shown in fig. 8, upon which isotherms have been drawn and the temperature of the fixed points given. In figs. 12 and 13 are such diagrams, 12 given in weight percent and 13 in mol percent. DISCUSSION OF THE FIELDS. A complete discussion of the wollastonite, of the pseudowollastonite and of the 5CaO.2Mg0O.6S8i0, solid solutions and their respective fields will appear in a subsequent paper. The general conclusions only will be indicated at this time. The pseudowollastomte, field—This field belongs to solid solutions whose compositions form an area bounded by the CaO.Si0,-CaO side line, the CaO.S8i0,-diopside line and a line extending from the compositions CaO 44-4, MgO 3-1, S10, 52-5, on the CaO.Si0,-diopside line to the composition CaO 46-7, MgO 3-5, SiO, 49-8, on the CaO. 810,-2CaO.Mg0O.2810, line and probably to the composi- tion CaO 50, Si0, 50 on the side line. The. wollastomte field—The evidence does no more than establish the existence of this tiny field which belongs to the most concentrated solid solution of diop- side in wollastonite which decomposes at the highest tem- perature. This solid solution containing between 3-1 and 3-0 percent MgO or approximately 17 percent of diopside has the highest decomposition temperature, 1340 +5°C, the pure wollastonite inverting to pseudowollastonite at 1200°C. The lmit of 3-1 to 3-5 percent MgO agrees with the limit. of 35-15 MgO (17 percent diopside) found by Allen and White as does the decomposition temperature of 1840°C with their observations.*” The 5Ca0.2Mg0.68i0, field—This field belongs to a series of solid solutions which are not stable at their melt- ing points and which lie on or near the 5CaO.2Mg0.6Si0. composition. The fact that the decomposition tempera- tures of these and other solid solutions rise sharply as “This Journal, 27, 1, 1909. Ferguson and Merwin—The Ternary System. 115 the composition 5CaO.2Mg0.6Si0, is reached was inter- preted as indicating the existence of this compound. Its decomposition temperature is somewhat difficult to deter- mine directly but from the liquidus relations must be 1365 + 5°C, the temperature which corresponds to point 13. The diopside (CaO.Mg0.2810,) solid. solution.—Diop- side has previously been shown by several investigators to form no solid solution with silica, forsterite or pseudo- - wollastonite. Similarly it does not form solid solutions with the compound 2CaO.Mg0O.2S8i0, to any great extent. _ A charge of the composition CaO 26-5, MgO 18-5, 810, 55, was found to contain after a 15 hour heat treatment at 1300°C, erystals of 2CaO.MgO.28i0, in such quantities as to indicate not more than a trace of such solid solutions. However, diopside forms a continuous series of solid solutions with clino-enstatite MgO.Si0,, a thorough dis- cussion of which has been given by Bowen. The CaO.Mg0.810, (monticellite) solid solutions.—The temperature relations along the monticellite-periclase boundary line 10, 11, are such as to indicate considerable solid solution between monticellite and forsterite.* The limit thus indicated would be about ten percent forsterite, or to the composition CaO 32, MgO 28-75, S10, 39-25. Owing to the difficulties encountered here, due to the great readiness with which magnesia crystallizes and the great | slowness with which it is resorbed, only a few confirma- tory experiments were made. ‘These indicated that the solid solution extends at least to the composition CaO 33, MgO 28, S10, 39. Attempts to prepare pure monticellite did not succeed. Instead of a homogeneous mass of this composition a mixture of crystals of «2CaO.SiO, and crystals of a monti- cellite solid solution was always obtained even though the original charge consisted of a glass in which very minute crystals of magnesia were imbedded. ‘This result may be explained by reference to fig. 14 which is an enlarge~ ment of this portion of the diagram given in fig. 8. The arrows indicate the direction of falling temperatures. The maximum C on the line 10, 11, represents the decom- position temperature of the solid solution D and there “The existence of such solutions was previously discovered but the some- what crude apparatus used in the investigation made the interpretation of the results an uncertain matter. P. Herman, Zeit., d. deutsch Geol. Ges. 58, 39, 1906. 116 Ferguson and Merwin—The Ternary System. must be a maximum on the line 8, 9, at B although due to the slight temperature gradient we have been unable to detect it. The field B, 9, 11, C is the field of the solid solution D and the field B, 8, 10, C is the field of the solid solutions with compositions on the line DM. The exact liquidus-solidus relations cannot be determined because of the difficulties inherent in the microscopic examination of these solutions. The decomposition temperatures along DM are evidently all lower than the temperature at D but one cannot say if they change gradually from D to M or if they pass through a minimum between D and M. If a minimum is present then the point 10 represents a glass which can coexist with a solid solution of an Fig. 14. 2190-510, Fic. 14—An enlargement of that part of the diagram given in fig. 8 which deals with the monticellite solid solutions with some additions designed to aid in the discussion of these solid solutions. intermediate composition to D and M. If a minimum is not present this may or may not be the case and the pure compound may be stable in the presence of the glass 10. Our inability to prepare the pure compound cannot be reconciled to this latter theoretical possibility and it would therefore appear reasonably certain that the glass 10 corresponds to a solid solution with a composition intermediate with D and M. The crystallization of a glass M of the composition CaO.MgO.Si0O, would be: 1. Liquid. 2. Magnesiaand liquid. The liquid composition varies from M to E along ME. 3. Magnesia, 22CaO.Si0, and liquid. The liquid com- position follows the line E 10 to 10. ae ie Ferguson and Merwin—The Ternary System. 117 4. The magnesia disappears and the charge becomes completely crystalline at 10 to form a mixture of 42Ca0O. SiO, and a solid solution X. The last hquid has a com- position represented by the point 10. The solid solution X lies on the line MD between M and D. Were it possible to make a reaction take place in the solid state in a reasonable time, pure monticellite would be formed when the mixture of a2CaQO.Si0, and the solid solution X were heated at temperatures below the decom- position temperature of the pure compound. Akermanite-—Many attempts have been made to explain the composition of the members of the melitite group of minerals (tetragonal in symmetry), and most of the resultant explanations have presupposed the existence of a mineral akermanite. Vogt*t assumed the formula of this pure compound to be 4CaO.38i0, although usually — part of the lime was ‘‘replaced’’ by magnesia or a like base. Day and Shepherd*? were, however, unable to obtain any evidence of the existence of such a compound in their investigation of the lime-silica series of minerals. Later Rankin and Wright*® noting the similarity between some of the properties ascribed to akermanite and those of the compound 3CaQ0.2Si0, (orthorhombic in sym- metry) suggested that the latter might be the akermanite analogue in the binary system. More recently Schaller,* recognizing the ternary nature of the melitite group, has stated that the correct formula for this second compound is 8CaO.4Me¢0.9Si0,. | Since the compound 4CaO.3S8i0, has never been pre- pared in the pure state and there is little real evidence of its existence, this formula may be regarded as purely speculative. The formula 8CaO.4Mg0.9Si0, is based on Schaller’s interpretation of two analyses?’ of a tetragonal Vesuvian mineral. This interpretation would need but little modi- fication if the formula were written 2CaO.Mg0O.2Si0.,, corresponding to the tetragonal ternary compound of this System. The essential optical properties of the analyzed aker- manite (1) and of the ternary compound (2) are compared as follows: “T. H. L. Vogt, Mineralbildung in Schmelzmassen, 96, 1892. * A. L. Day and E. 8. Shepherd, this Journal, 22, 280, 1906. *G. A. Rankin and F. E. Wright, this Journal 39, 1, 1915. *“ W. T. Schaller, U. S. Geol. Survey, Bull. 610, 1916. “See EF. Zambonini, Mineralogia Vesuviana, 255, 1910. 118 Ferguson and Merwin—The Ternary System. (ip leoae2 1-639 (2) 4-63 1-638 We have been unable to prepare a compound or solid solution having more nearly the formula 8Ca0.4Mg0. 9Si0,. The compound 2CaO.MgO.2Si0,, as far as we know, forms no appreciable solid solutions. In this connection attention may be called to the con- fusion which may arise from the use of such formulas as 4R”0.3810, applied to minerals. For the sake of sim- plicity let us assume that we have a case in which R”O Fie. 15. Melt Ca0-Mg0-2Si0, + Melt 2Ca0- MoO -2Si0, + Melt Ca0-Mg0-2Si0, + 2Ca0-MgO- 2Si0, Ca0- MgO - 2Si0, 2Ca0+Mg0- 2Si0, Fig. 15—The binary system CaO.Mg0O.28i0,-2CaOMg0O.2S8i0.. wit. per cent. represents but two oxides.*® As so used R” may repre- sent any one of three things: either (1) two elements in a definite ternary compound; or (2) two elements in solid solutions containing no ternary compounds, but only component oxides and binary compounds, or binary com- pounds alone; or (3) two elements in solid solution involv- ing ternary compounds, either alone, or with binary compounds, or with component oxides or with both. The tridymite-cristobalite inversion. The tridymite-cristobalite transformation is very slug- gish even when it takes place through solution. Fenner’® “Similar statements would apply to minerals containing more than three components, but with additional complications. ° This Journal (4), 36, 331, 1913. Ferguson and Merwin—The Ternary System. 119 in his investigation of it used a flux of sodium tungstate. We have studied it in melts of our ternary system. We selected a composition, CaO 24, MgO 7, SiO, 69, which lies within the silica field and melts completely at 1536°C. The tridymite and cristobalite present in the various quenches made could not be separated and analyzed, therefore the only evidence that they are little if any affected by solid solution rests upon determinations of refractive index. The values obtained agree within + 0:003 with those of purest natural crystals and with Fenner’s values for material formed in molten sodium tungstate. Our observations are given below. Fig. 16. a 2Ca0-Si0, + Melt 2Cad Sid, 2Ca0-MgO 2510, Fic. 16.—The binary system 2Ca0O.MgO2Si0,-2Ca0.8i0,. wt. per cent. 1. A charge containing only tridymite plates and glass was prepared by heating the original material which - contained cristobalite for 16 hours near 1370°C, the eutectic temperature being 1320°C. Portions of this charge were then. given the following treat- ments. (a) Heated 5 hours at approximately 1530°C. The charge then contained much cristobalite. (b) Heated 5 hours at 1515°C and then 10 hours . during which time the temperature fell to 1500°C. The charge contained cristobalite; no tridymite could be identified. (c) Heated 91% hours at 1496°C. Much tridymite, no cristobalite identified. Ferguson and Merwin—The Ternary System. 120 ‘yuod dod YM “OIGZOSW'OROS“OIN'OXO wWoysds Arvurq eyT—/T “dIyf 70!S Z-0OW -0%D Zz “0!lS -0”O 70!1S Z-OOW-0%9 Z + UIs PHOS “O15 -ObO8 ool! UI9g piles 2015-909 % 00zI UIOS PHOS 01S -0PD H+ UlOS PIl°S O1S OPOP 291ISZ-OfW-0DZ + les PICS “OIS-QKD%” OOEI OoEt P ujog pljos OO! O!s -003 © “100! HOW +70!SZ:OOW - OWDZ 12W + UloS | NOS “OIS-OlWD % H2W +# UI0S PIlOS “OIS- O”D %0 0091 LT “OM Ferguson and Merwin—The Ternary System. 121 2. The charge which contained only tridymite was mixed with some of the original material forming a charge containing both cristobalte and tridymite. This material was treated as follows: (a) Heated at 1515° for 3 hours. Both tridymite and cristobalite identified. (b) Heated at 1485° for 3% hours. Both tri- dymite and cristobalite present. (c) Heated for 16 hours, the temperature falling from 1500°C to 1483°C. Little if any change. 3. A charge containing cristobalite + glass — heated all night at 1464°C. No tridymite formed. These results confirm the observations of both Fenner and Bowen®*! upon the sluggishness of this inversion, and because of this sluggishness it is impossible to fix upon an exact value for the inversion temperature in this system. Our results certainly indicate a value in this silicate system which lies below 1500°C with cristobalite as the stable high-temperature form. Fenner found in the tungstate melts, 1470 + 10°C. Only slight, if any, solid solution could have been present to affect our meas- urements or Fenner’s, which are in substantial agree- ment. THE BINARY SYSTEMS WITHIN THE TERNARY SYSTEM. The presence within the ternary system of so many compounds which melt incongruently and also so many sold solutions, renders the binary systems rather few in number. The systems CaO.Mg0O.28i10,—2CaO.Mg0O. 2810, and 2CaO.Mg0.281i0,—2CaO.8i0O, are of the simplest type and are given diagrammatically in figures 15 and 16 which were obtained by interpolation from the melting temperatures determined for compositions lying in the fields of these compounds. The system CaO. Si0,—2CaO.Mg0.2Si0, is more complicated including as it does several series of solid solutions. The evidence upon which the purely solidus relations are based will be given in a later paper but for the sake of completeness the ate. results are included in the diagram given in ee ny “This Journal (4), 38, 245, 1914. 122 Ferguson and Merwin—The Ternary System. In conclusion, thanks are due Dr. N. L. Bowen for his friendly criticisms and Mr. G. A. Rankin for certain pre- liminary results which he generously placed at our dis- posal at the commencement of the investigation. SUMMARY. The ternary system lime-magnesia-silica has proved to be the most complicated of the four possible ternary systems which may be constructed from the four oxides, lime, magnesia, alumina, and silica. The crystalline phases which are definite compounds and which appear as primary phases are as follows: Lime; magnesia; silica (tridymite and cristobalite) ; aCaQO.SiO, (pseudowollastonite); 3Ca0.28i0,; « and B 2CaO.Si0O,; MgO.Si0, (clino-enstatite) ; 2MgO.Si0, (for- sterite) ; CaO.MgO.2S8i0, (diopside) ; 5CaO.2Mg0.6810, and 2CaO.Mg0O.2S8i0,. The melting point of 2CaO.MgO. 2810, is 1458° + 5°C and the decomposition temperature of 5CaO.2Mg0.6S8i0, is 13865° = 5°C. In addition to these, crystals representing several solid solutions also appear as primary phases. The solid solu- tions are: 1. A complete series with clino-enstatite and diopside as end members, generally known as pyroxenes. 2. The pseudowollastonite solid solutions whose com- positions form an area bounded by the following lines: (1) the CaO.810,-CaO.Mg0O.2S810, line; (2) a line run- ning from the composition CaO, 44-4, MgO 3-1, SiO, 52-5 on the above-mentioned line across to the composition CaO 46-7, MgO 3-5, Si0, 49-8 on the CaO.S10,-2CaO.Meg0O. 2810, line; (3) then either the last-mentioned line back to CaO.Si0,, or, more probably, an approximate continua- tion of line (2) to about the composition CaO 50, Si0, 00, on the side line. 3. The wollastonite solid solutions; these extend to about 17 percent diopside or 3:2 percent MgO at the higher temperatures. The most concentrated of these solid solutions along the diopside line (the 17 per cent) decomposes at 1340° + 5°C, and this solid solution is the only one represented on the liquidus. 4. The 5Ca0.2M¢0.6Si0, solid solutions. Only a few of these solid solutions which are decomposed at the higher temperatures near the decomposition-temperature Ferguson and Merwin—The Ternary System, 1238 of the pure compound are stable in contact with a suitable liquid. a Certain members of the monticellite solid solutions. Monticellite takes up forsterite in solid solution to the extent of about ten per cent and the decomposition tem- perature of the solutions is thereby raised. Monticellite itself probably decomposes at too low a temperature to ever occur at a primary phase. The temperature-concentration relations of the liquids which may be in equilibrium with each of these phases have been thoroughly investigated where necessary by means of the quenching method, and the results obtained have been correlated with the existing data on the remain- der of the ternary system. The compounds 5CaO.2M¢0.6810, and 2CaO.Mg0O. 2810, have not been prepared previously. Attempts to prepare a compound of the formula 8Ca0.4M¢0.9Si0, (Schaller’s akermanite) gave negative results. The monticellite solid solutions and the compound akermanite are discussed at length but the wollastonite and the 5CaO.2M¢0.6S10, solid solutions are only briefly mentioned as they will be made the subject of a sub- sequent paper. Experiments were made on the tridymite-cristobalite inversion temperature, which was found, for this system, to be below 1500°C, in approximate agreement with Fen- ner’s original value of 1470°; the great sluggishness of the inversion precluded a more exact determination on our part. Geophysical Laboratory, Carnegie Institution of Washington, Washington, D. C., April, 1919. 124 Ichikawa—Notes on Japanese Minerals. Art. VIII.—Some Notes on Japanese Minerals; by Suim- maTsu IcHIKawa.! VIII. Secondary report on the natural Etchings of Calcite Crystals (I and II). Natural etchings of calcite crystals from Shimoshinjo, Kehizen Province, have already been described in this Journal.? Since then, I have repeatedly visited this and other calcite localities and collected additional crystals more etched than those before described. These speci- mens are illustrated in the accompanying pages, 125, 127, TandIl. The striations formed by etching can be barely observed by the naked eye and the pits, elevations, ete., can only be investigated minutely under a magnification of 75 to 140 diameters. The locality of the specimens is Shimoshinjo, Echizen. Fig. 1 (1) shows the etching of a scalenohedral crystal; A is a front view (X95); B, a horizontal projection on the vertical axis of A. C, D, HE, ete. show varieties of natu- ral pits on the face mR. E is the combination of two pits C and D; F is more etched than D, the three lateral sides sloping down to the base; G, H, I, ete. show a group of the C or C, E type of pits, etc. respectively. C some- times shows a curved form as in the external part in G and H; the angle acb is for C—140°; D=30°; E and [=140°; -F = 30°. J, .K, , ete, shew varies natural pits on the face mR. K is a combination of two individuals of the J type pit. The angles for J are: acbh==80°: dce==110"°% for, 2 ach — 30 7a =110°; adb=60°. M shows a trigonal pyramidal ele- vation on the face mRn, in horizontal projection. The rhombic plane (abed) with striations is a face of a rhom- bohedron formed by etching; the trigonal plane on the top has a strong luster and is a new face formed by etch- ing. N shows a face (p) of trigonal pyramidal elevation (M), in horizontal position. The angles are: ab’c = 90° ; ade = 70°; bea=30°. The direction of the isosceles triangle (bea) in the figure is opposite to that of acb in D, but the planes of both the triangles are parallel. Rhombic plates (p) in A, and trigonal plates (¢) in B are ‘For two earlier papers, see this Journal, vol. 42, pp. 111-119, August, 1916; vol. 44, pp. 63-68, July, 1917. *Ibid., vol..42, pp. 113-115, 1916: 125 Ichikawa—Notes on Japanese Minerals. Ly Ie | (ill S. Ichikawa del. I. Natural etchings of calcite crystals. 126 Ichikawa—N otes on Japanese Minerals. elevations formed by etching; the striations on the faces mn, ete., also are formed by etching, and the striations are parallel to the direction of cleavage. Fig. 2 (A) shows a erystal strongly etched; the pyra- mid is rounded and has numerous new forms like an acute trigonal pyramid on its surface; this new form is similar to C of figure 4 (this Journal, vol. 42, pp. 114, 1916), but the former is a front view and the latter is drawn in perspective. B shows the relation between the outline of the top of the new form and the edges of the original erystal in a horizontal projection. Fig. 3 shows the etching of a prismatic crystal. Upper Devonian S of Iowa; by C. L. Fenron. nae Sees oo ART. X XV. > Wheuts the eee of poniene Metnrphia : . -by.F. L. Huss . ie 3 eee RG Go ie Arr. XXVI.—Structural Features of the Abajo Mountains, Utah; ae R. THorpE : SCIEN ELEC: CEN, TELLIGEN OR. Chemistry and Ph ysies—The Single Dellectian Method bE Weighing, P. a M.-P, Brinton, 390.—A Method of Growing Large Perfect Crystals. as Solution, R. W. Moore: Modifications of Pearce’s- Method for Arsenic, — 391.—New Fluorescent Screens for Radioscopic Purposes, P. ROUBERTIE * and A. NEMIROVSKY: Scattering of Light by Solids, R. J. Strurr, 392.— — Apparatus for the Direct Determination of Accelerations, 2 Gauiratn, % 394 ees an Geology—Shore Processes and Shoreline Development, D. W. Joamabe 395. a World-Power and Evolution, E. Huntineton, 396--Brachiopoda of the Australasian Antarctic Expedition, 1911-1914, J. A. Tuomson, 397.— Pelecypoda of the St. Maurice and Claiborne Stages, G. D. Harris, 398.— es Tertiary Mammalian Faunas of the Mohave Desert, J. cc MErRRIAM, 399. cee Miscellaneous Scientific Intelligence—Thirteenth Annual Report of the Prosi- dent, Henry S. PrircHett, and the Treasurer, RoBERT A. FRANKS, of © the Carnegie Foundation for the Advancement of Teaching, 400. —Publi-_ cations of the Carnegie Institution of Washington, R. S. Woopwarp, 401.— — National Academy of Sciences: The Birds of North and Middle America, R. Rip@way: Biographical notice of Joseph Barrell, CHARLES ‘ScHucH- bs ERT, 402. 2 hE Se Obituary—F. Brawn, 402. OF SCIENCE. : oa S. DANA. oun USE & TAYLOR CO., PRINTERS, i123. 1emPLe sTREZT. ae year, in advance, $6.40 to countries in the iP nitie numbers 30 cents ; Mo; 271; one acess MINERALS AND HOW TO. STUDY THEM 2 By EDWARD §S. DANA, Professor of Physics, and Curator of Mi 1e1 Yale University. Second Hdition, Revised. Teaches thé beginner to know the more commonly. occurring nines, serves as the foundation for a more extended study. vit 380 pages. 5 by 77. 319 figures. Os $1, ” net, ge alass secon Of MINERALOGY | FORD, Assistant Professor of Mineralogy, Sheffield Scientific “Sc of Yale University. . For the mining engineer, the. geologist, the prospector, the collector, 2 S The treatment is brief and direct. vii+460 pages. 5 by 74. 857 figures and 10 A. = Flexible binding, $3.00; Cloth, $2.50. oe eee oy eee OF MINERALOGY _ By EDWARD §. DANA. This book gives the student the means of becoming practically fami ia: with all the modern methods of investigation now commonly applied. ¥ vii+ 598 pages. 6 by 9. 1008 figures and a colored plate. Sy ee = Cloth, ve a Mob.) ean e a a Sixth Edition, by EDWARD S. ‘DANA. ‘With Appendices I ond ee pleting the work to 1909. ; A complete classification of all the mineral eS according { to. a poe - arrangement. eat Ixxxiv +1323 pages. 62 by 10. Over 1400 figures. ; oe : Half leather, $15.00 net. — ay THIRD APPENDIX to the above Work, completing the same to 1915, issued separately. : ey xili+87 pages. 62 vs 10. Cloth, $2.00 net. 5 a aes ee : publications. JOHN WILEY coe <¢Note on the Shape of Pebbles,’’ this Journal, vol. 39, pp. 300-304, 1915. J.T. Jutson—Rounding of Pebbles. 431 ately adjacent. Moreover, rocks, rounded at the surface, may be seen breaking away from the parent mass. (2)—The greenstone pebbles are scattered at all heights from the bottoms to the tops of the hills. This fact, therefore, precludes the action of lake waters and also of stream action, unless, in the latter case, the peb- bles were laid down on the tops of the hills (when the general land surface stood approximately at the height of such hills) and have been subsequently transported by gravitation down their sides. The close proximity of the parent rock to the pebbles, however, is against this possibility. (3)—Strong water abrasion would reduce most of the soft sediments and porphyries to powder rather than form rounded pebbles. A third hypothesis is spheroidal weathering, which, although operating among the greenstones by flaking, as described below, does not appear to meet all the facts. No actual peeling of concentric coats, in either of the classes of pebbles described, has been seen; and the stratified sediments and decomposed foliated porphyries are not favorable rocks for this mode of weathering. A fourth hypothesis that they are derived from old conglomerates is equally untenable in view of their clear relationship to the rocks im situ, as already shown. In the greenstones, the iron crust or film on the joint faces is important. Until broken by ordinary weather- ing agencies no rounding, as a rule, takes place; but once the crust is penetrated it tends to be slowly removed over the whole surface, and the grey rock within begins to assume a rounded form. Examples are obtainable of various stages of this destruction of the crust. An iron crust does not cover the sediments and porphyries ob- served, hence the process of pebble formation is not delayed for a time as in the greenstones. Flaking in small fragments, owing to temperature variations, may and probably does take place in the rocks of both classes of pebbles; but in the case of the greenstones practically only when the crust has been broken. This flaking may be regarded as a phase of spheroidal weathering, and doubtless is partly responsi- ble for the greenstone pebbles. The chief agent, how- ever, of the rounding of the other class of rocks, and a major or minor agent in the formation of the greenstone 432 J. T. Jutson—Rounding of Pebbles. pebbles seems to be the direct action of the rain in beating upon the surfaces of the rocks (in the case of the green- stone when the iron crust has been broken) and wearing them away without any rock particles to act as abrasion tools. Under this action the corners are most likely to be first removed and hence the rounded appearance. There may also be some latent structure in the rock which, de- spite the angular jointing, assists rounded weathering; but this would hardly seem to apply to the thin-bedded sediments and decomposed foliated porphyries. The unrounded irregular under surfaces of many of the sedi- ment and porphyry pebbles may be accounted for by the fact that the rain cannot beat directly on such surfaces. Where, however, a pebble has been rounded on its whole surface, this appears to be due to all portions having been directly exposed at different times to the rain, ow- ing to the rock fragment which became the pebble having changed its position by reason of the slow gravitational movement, which all loose fragments are subject to, and which is especially well illustrated in sub-arid Western Australia. The greenstone pebbles are also more abundant and freer from iron oxide films at places such as the base of a hill or on a tiny bench on the hillside, where the flow of the surface rain water has been more concentrated than usual, or where it may have lodged for a little while. The flow, however, has been so insignificant that it can- not have any direct abrasive power akin to normal stream action, but it seems to act in keeping the surfaces of the rock fragments largely free from the deposition of iron and hence assisting their rounding by the rain. At the foot of the hills, percolating meteoric water may ooze out and act in the same way. Certainly in other places than those mentioned the pebbles have more iron oxide films, and their disintegration must therefore be retarded. It is the occurrence of the grey pebbles at the foot of lake cliffs that suggests, until a closer investiga- tion has been made, that they are normally waterworn pebbles due to their abrasion by stream, lake or old sea waters. Wind action has probably had some slight effect on the pebbles, but that need not be discussed here. Fragments of decomposed rocks from the oxidized zone thrown out from mining shafts sunk on the West- J.T. Jutson—Rounding of Pebbles. 433 ern Australian goldfields, have in places become quite rounded on those portions exposed to the weather since their removal from below the surface; and the beating of rain appears to be the cause of this. At a mine inspected by the writer, a number of green- stone pebbles, well-rounded and apparently truly water- worn by abrasion, were shown as having been ordinary angular fragments brought to the surface and rounded by water splashing them from the pump. ‘This explana- tion was not accepted as genuine at the time, although the good faith of the informant was not questioned; but the pebbles were regarded as having by some mischance found their way to their then position. In view, how- ever, of the observations on which this paper is based the writer believes that the statement made as to their origin is probably true. The greenstones of the Western Australian goldfields are usually much altered. rocks chemically and mineral- ogically, and this alteration may assist the mode of weathering here described, but further investigation is necessary to come to a conclusion on this point. COMPARISON WITH ROCK FRAGMENTS IN ADJACENT CANYONS. The country of which the greenstone hills referred to above form a part, is dissected into young steep V- shaped canyons up to 100 feet in depth, which are entirely due to normal stream erosion. Consequently, it is interesting to compare the greenstone rock frag- ments there found with those described in this paper. Careful observation shows that the rock debris of the stream channels is, on the whole, angular or sub-angular, hardly any fragments having more than their corners rubbed off and blunted. The rounded forms described in this paper are quite absent, so that it is clear that stream abrasion under present conditions cannot pro- duce these forms. As, however, the stream channels are dry nearly all the year it is difficult to understand—if past erosive action be rejected—why such rounded peb- bles are not produced in the stream beds by the same agents that are producing them on and at the foot of the hills as described in this paper, especially as the stream rock fragments are of similar rocks and largely free from iron films. The only suggestions as to the reason of this that the writer can make are that the rock frag- 434 J.T. Jutson—Rounding of Pebbles. ments of the water channels are being moved fairly fast down stream by the intermittent stream action, and that this movement prevents the rain from beating long enough on one particular surface to bring. about the rounding ;®> and also that when rain falls the channels must at times receive sufficient water to cover the debris on their floors, and thus prevent further direct falls of rain on to the rock fragments. Be this as it may, the explanation given for the rounded pebbles of the hill- sides, and at their bases on lake shores, appears to be the only feasible one. It at least appears certain that they are being rounded in their present positions, and that they are not due to past normal stream, lake, or marine action. THE BEARING OF THE ORIGIN OF THE PEBBLES ON CERTAIN QUESTIONS. A true conception of the origin of the rounded pebbles is required in view of the incorrect inferences that may be drawn from their occurrence, if such pebbles are assumed to be due to either stream, lake, or marine ac- tion; such inferences must be that large rivers or lakes (probably freshwater) earlier existed in the area; or that the land has been recently subjected to marine ero- sion. The nature of the pebbles does not support any of these deductions. H. E. Gregory has shown that, under certain condi- tions, pebbles may be carried considerable distances by streams and yet remain angular or sub-angular,’ and that ancient river gravels may not in all cases be dis- tinguishable from residual deposits resulting directly from weathering.® In the area of which this paper treats, these statements are confirmed to the extent that the true stream-borne pebbles are angular and sub-angular, while the rounded pebbles have received their present shapes in practically their present positions, which are close to the parent rocks. The angular character of the stream-borne peb- bles may however, be entirely due to the short distance they have travelled. Perth, Western Australia. *The absence of rounding in these stream fragments would also seem to imply that flaking is not a very potent agent in the formation of the greenstone pebbles described in this paper. "Op. cit. p. 302. * Op. cit. p. 303: J. T. Jutson—Sheet-flows or Sheet-floods. 435 ' Art. XXITX.—Sheet-flows, or Sheet-floods, and their asso- ciated phenomena in the Niagara District of ‘sub-arid south-central Western Australia; by J. T. Jurson. INTRODUCTION. Sheet-floods occur in arid and sub-arid countries, the classical exposition from a physiographic standpoint be- ing that by McGee! in regard to an area in North Amer- ica. He attributes considerable erosive power to the sheet-flood, but his conclusions have not been generally accepted by American physiographers and geologists. Sheet-floods occur in the sub-arid portions of south- central Western Australia, but so far as the writer is aware, no detailed description of them has ever been given, nor has their work in the role of erosion been dis- cussed. ‘T'he present paper is therefore a contribution to the subject. It may at once be stated that the sheet-floods here dealt with do not, in the writer’s opinion, possess the erosive activity attributed by McGee to the sheet-flood in the area specially studied by him; but the writer does not presume to question McGee’s conclusions for that area. This paper is only concerned with the manifestation of the sheet-flood in sub-arid south-central Western Aus- tralia, as exemplified in the Niagara District.2, The term ‘“sheet-floods,’’ however, will not be used; ‘‘sheet-flows’’ appear to be more suitable to describe the widespread moving sheets of water as a whole, some of which are quite gentle in their action, and could hardly be classed as floods. SUMMARY. Sheet-flows in sub-arid south-central Western Aus- tralia are broad, shallow, but not necessarily continuous, sheets of water, which traverse the gently-sloping sides and the flat bottoms of wide, open, shallow valleys, and the floors of plains. They are divided into three classes, *McGee, W. J.: ‘‘Sheet-flood Erosion.’’ Bull. Geol. Soc. Am. vol. 8, pp. 87-112, 1897. *Niagara is a decayed mining township on the great sub-arid plateau of Western Australia. It is 118 miles north of Kalgoorlie and is 1460 feet above sea-level. The average rainfall is slightly under 10 inches per annum. | Am. Jour. Sc1.—FourTH SERIES, Vou. XLVILI, No. 288.—DrcEemBeEer, 1919. 30 436 J.T. Jutson—Sheet-flows or Sheet-floods. namely: the rill type, the smooth-bottomed valley type, and the furrowed-floor type. They appear to be rather agents of deposition than of erosion. The term ‘‘sheet- flows’’ is used in preference to ‘‘sheet-floods,’’ so as to inelude all kinds of wide, shallow, moving bodies of water, no matter how gently they may flow. DESCRIPTION. Sheet-flows, as noted above, may be divided into three classes, which vary according to the nature of the ground over which they flow. The divisions are perhaps some- what arbitrary, but the types exist and the classification is convenient for reference and description. 1. Rill type—This type consists of the broad sheets of water which flow down the smooth surface of the long, undissected gently-sloping sides of shallow, wide, open slowly-corrading valleys. There is no limit as to the width of water that may flow, except the length of a val- ley side, and the area affected by the fall of rain, which has caused the occurrence. The water is not actually continuous across the line of flow, but the sheet is made up of countless rills of varying width, and not separated by more than a few feet. ‘These rills may be merely films of water not more than one inch in depth or they may reach a depth of: perhaps six inches, this variation being due to the very slight inequalities of the ground. The flow 1s so widespread and shallow that even with a mod- erate slope, and on soil-covered areas, the water usually has no power of cutting even the smallest trench or furrow; the surface of the ground remains quite smooth and unbroken, although the spaces between the small trees and shrubs are commonly bare of vegetation. The water will however, if possible, concentrate itself, as is Shown where ruts are worn in the surface by cart wheels. It takes possession of these ruts and deepens them, to form a narrow shallow channel, the width of which seldom exceeds the width between the two wheel ruts, and the depth of which is scarcely ever more than 2 feet, so little power of excavation does the water pos- sess on these broad gentle slopes. In fact, in many places the channel tends to become filled by drifting sand, which the flow of water is unable to remove. The mile- upon-mile of very gently-sloping soil-covered ground J.T. Jutson—Sheet-flows or Sheet-floods. 437 which is yet absolutely smooth and unfurrowed,? forms one of the most striking features of the country. The rills of water have no power to directly move for- ward the angular fragments, of various sizes, of quartz, jasper and ironstone, which are frequently spread over the surface of the ground. On soil-covered gentle slopes, these rills of water help to form minute soil-terraces from 1 to 6 inches in height. These terraces are primarily due to the occurrence of a surface film of soil, more compacted than the portions beneath, owing to the deposition of material on evapora- tion of water’ brought to the surface by capillary attrac- tion. 2. Smooth-bottomed valley type-—This type occurs in wide flat-bottomed valleys which generally have a mod- erate amount of vegetation in the form of small trees, and large and small shrubs. These valleys possess a fairly well-marked drainage line along their floors, by means of one or more channels, which are from 6 to 20 feet wide, are usually not more than 4 or 6 feet deep, and are almost wholly cut through detritus. It is seldom that there is but one channel, although there may be a main one, for the tendency is to form several, which, how- ever, frequently die out, unite and reform. In other words the drainage line is ‘‘braided.’’ These channels occur in wide, smooth, level, soil- covered flats, which consist of detritus (chiefly fine), brought down by the water and spread evenly over the floor of the valley, the long gently sloping sides of which rise gradually from such floor. As the valley is followed downstream the flats become wider and wider, and the valley sides less and less pronounced, until practically a slightly undulating plain results, often without distinct drainage lines. The channels of the better defined portions of the val- ley are the main carriers of the water. The latter comes from the hillier country, where of course in the narrow valleys the erosive power of the water is great, also from the numerous rills, which form the first type of sheet- flow; and it naturally collects in and follows the chan- nels. The rains need not be very heavy or lasting before the water overflows into a broad, shallow sheet, which *If the country be of the sandy loam or loamy sand type with abundant ‘“‘mulga’’ scrub much of the water will rapidly soak into the ground. 438 J. T. Jutson—Sheet-flows or Sheet-floods. covers or partly covers, according to the volume of the water, the soil-covered flats. Along the latter, floating vegetation in the form of leaves, twigs and small branches of trees and shrubs is carried by the water, and becomes caught at the base of the growing vegetation, remaining there for a time as evidence of the width of the flow of the water. When the rain ceases, and the channels become relieved, the water on the flats tends to gradually drain to the channels, but much is left as pools which gradually disappear by soakage and evaporation. The main function of the water outside of the channels appears to be neither to corrade nor to transport but to deposit fine detritus; and thus to widen, raise and smooth the general valley floor. This is due to the loss of veloc- ity by the spreading out of the water, aided by the ob- structing vegetation. The general scarcity—so far as the writer’s observations go—of pebbles on these flats, Mies eile Channels Fie. 1. Cross section illustrating smooth-bottomed valley type of sheet- flow. Shows bedrock below with surface debris on slopes above; in center, fine detritus with occasional pebbles. It is to be noted that some sandy slopes are almost free from rock debris. and in natural or artificial cuts through them, also indi- cates the low transporting power of the water. This scarcity of pebbles is in places in marked contrast to the gently sloping sides of the valley, which may have abun- dant rock fragments up to three inches in length on their surfaces. The above statement is generally true for the class of country described, but of course modifications may occur, such as the surface being somewhat furrowed instead of smoothed; and minute soil-terraces may occur where any slope exists. 3. Hurrowed-floor type—This type is particularly characteristic of some wide, treeless, or almost treeless, salt bush and samphire flats, which form such a promi- nent feature in the landscape. ‘These flats may be sev- eral miles wide, and in places lie between ridges which tend to rise sharply from the plain, thus forming a broad J. T. Jutson—Sheet-flows or Sheet-floods. 489 flat-bottomed ‘‘valley’’; or they may be extensive areas without any definitely observed relation to the drainage, except that they are low-lying portions which may com- municate with lakes or which may practically form shallow basins with no outlet. Probably most of these flats possess a certain fall for at least part of their areas, and this fall enables the water, after heavy rain, to flow . along in broad thin sheets. | The absence of definite channels is a marked feature, but in lieu of these, much of the flat may be scored by very numerous furrows averaging perhaps 9 inches in depth and 18 inches or 2 feet in width. These furrows frequently join one another, and as frequently die out, fresh ones taking their places. The absence of trees and tall shrubs and the presence of the salt bush and other small shrubs, mostly not more than 2 feet high, together Fig. 2. Fie. 2. Cross section illustrating furrowed-floor type of sheet-flow. Bedrock below with fine detritus containing occasional pebbles above. with the covering of detritus of sands and muds, facili- tate the formation of these furrows. The water sweeps and swishes around and among the small shrubs, scour- ing the detritus out to form furrows, and depositing it around these shrubs until they may be half buried. The furrows must be ever changing as the ever varying small streams gouge out in one place and fill up in another.‘ The irregular distribution and heaping up of the detri- tus enable, on the cessation of the rain, numerous small pools to be formed, the water of which soon soaks into the ground or evaporates. The net result of much of the water action seems to be merely the redistribution of the detritus over much of the area, although rock waste must, of course, be continually brought from the higher por- tions of the country. Much of the fine waste, however, is no doubt removed by the wind. Perth, Western Australia. *Wind action has probably some effect in both the formation and removal of these hillocks. The latter are comprised in the ‘‘Neulinge’’ or olan See ‘‘Das Gesetz der Wiistenbildung,’’ 2d Ed., pp. 70-71, 440 N. L. Bowen—Cacoclasite from Quebec. Arr. XXX.—Cacoclasite from Wakefield, Quebec; by N. L. Bowen. In 1883 crystals of a mineral found in blue calcite near Wakefield, Quebec, were described by Lewis! and given the specific name cacoclasite. Later they were further investigated by Genth in particular,? who proved that the crystals were made up of a mixture of materials and were, therefore, pseudomorphs and not entitled to rank as amineral species. Genth’s chemical investigation led him to believe that the crystals were a mixture of quartz, calcite, apatite and material of indefinite composition and that they were pseudomorphs after scapolite. Caco- clasite is apparently peculiar to this Canadian locality. In looking over some material from Wakefield in the University collection, fine specimens of this cacoclasite were noted and in checking their nature under the micro- scope it was found that the mixture represented does not correspond with that deduced by Genth and is, in fact, considerably simpler. The material was examined in powder form in immersion liquids, a method that is particularly well adapted to the identification of the con- stituents of a fine-grained mixture. Cacoclasite may have crystals of other minerals coating its surface and these may project into it but, if a crystal free from such foreign material is selected and crushed for microscopic examination, it is found to consist of only three minerals. Calcite (© 1-66) is fairly abundant and apatite (n= 1-645) is present in small amount but the main constitu- ent is an isotropic substance of index 1:74. No quartz is to be seen. If some of the powder is warmed with hydrochloric acid, calcite and apatite are removed and the residue is made up entirely of the isotropic substance. This substance shows no sign of cleavage and even after boiling with strong HCl, there is no suggestion of attack. It is evidently the mineral grossularite. That the cacoclasite consists of grossularite, calcite and apatite is borne out in a most striking manner by Genth’s analyses. He gives two analyses of which that numbered I was made on the ‘‘best’’ material. It is given below together with a recalculation of the mineral constituents represented. Proc. Acad. Phila., 1883. * This Journal, 38, 200, 1889. N. L. Bowen—Cacoclasite from Quebec. 441 Composition of Cacoclasite (Genth). Mols. Calcite Apatite Rest. Ratio. H,O 1-04 co, 6-73 -153 -153 SiO, 31-52 523 523 3-02 P.O; 2-19 015 015 Al1,O; 17-34 -170 ; 1701 1.00 Fe,0; 0-51 003 003 { MgO tr. CaO 40-95 -729 -153 -050a 526 3-04 Na,O tr K,O tr aInel. CaO — CaF,. The material analyzed by Genth was evidently, grossu- larite 78-8 per cent, calcite 15-3 per cent and apatite 5-2 per cent. Believing that his tests indicated the presence of free quartz, Genth decided that it was a mixture of quartz, apatite and calcite with an indefinite mixture of other minerals. It is worthy of note that Haines’ analy- | sis likewise shows a ratio Si0,: Al,O, of almost exactly 3. Genth’s ‘‘best’’ material evidently corresponds exactly with the best material powdered for microscopic exami- nation. In the case of Genth’s analysis No. [1 on poorer material, it is necessary to assume that it represents, besides the three above constituents, about 7 per cent kaolinite and 2 per cent tremolite, both of which are to be found on microscopic examination of cacoclasite into which crystals of other minerals project. They are com- monly tremolite needles, sometimes changing to tale and prisms of scapolite (?) altered to kaolin. In no case does the microscope reveal the presence of quartz and it can only be assumed that the method adopted by Genth of distinguishing free silica from the silica of a silicate was not to be relied upon. Genth expresses the opinion that cacoclasite is second- ary after scapolite. This conclusion is hardly borne out by the measured values of the angles. While occasion- ally prismatic, cacoclasite usually has the appearance of a cubo-octahedron. Its departure from isometric sym- metry is not obvious and it is necessary to measure the angles before it becomes apparent. The faces are always rough, with an eroded appearance and a peculiar glazed surface. Frequently, they are distinctly concave. By placing a drop of oil on a face and covering with a cover slip, one obtainsea plane parallel to the face and capable of giving a good reflection. Using this method and 449 N. L. Bowen—Cacoclasite from Quebec. avoiding concave faces, angular values for cacoclasite were obtained that are believed to be fairly reliable. The values are very close to those for sareolite with which they are compared below. The relationship of cacoclasite to sarcolite in angles was noted by Lewis. Sareolite. Cacoclasite. ec r=5l1° 27’ 51° R29" ec e—41° 35’ A1°- 4G" a r= 56° 26’ aye ey The great similarity in angles and the identity in habit make it necessary to regard cacoclasite as a pseu- domorph after sarecolite. Sarcolite has the composition (Ca,Na,);,Al,(Si0,), and in its typical occurrence Ca: Na,=—9:1 nearly. The change from sarcolite to grossu- larite Ca,Al,(Si0,), is, therefore, not a great one, indeed it might be termed paramorphism without seriously stretching the truth. A marked decrease of volume is ' involved, however. Sarcolite of the composition of its typical locality (G—2:-9 Rammelsberg’) would give a volume of grossularite (G= 3:5) approximately equal to Yo per cent of its own volume. It is worthy of note, therefore, that the ‘‘best’’ cacoclasite of Genth contains approximately 75 volume per cent grossularite. This correspondence suggests that cacoclasite was formed by the alteration of sarcolite to grossularite without change of volume, the resulting voids being occupied by calcite and apatite. . SuMMARY. ‘Chemical, microscopic, and crystallographic evidence all point to the fact that cacoclasite is a pseudomorph (essentially a paramorph) of grossularite after sarcolite with calcite and apatite filling the voids produced by the reduction of volume involved in the change. Mineralogy Department, Queen’s University. A. F. Rogers—Manganese Mimerals. 443 Arr. XXXI.—An Interesting Occurrence of Manganese Minerals near San Jose, California; by Austin F. RoGERs. For some years a huge bowlder of manganese ore situ- ated on the bank of Penitencia Creek below Alum Rock Park which is about five miles east of the city of San Jose, Santa Clara County, California, bore a placard which proclaimed it to be a meteorite. All geologists familiar with it knew that the so-called meteorite was simply manganese ore, for it showed a dull black mineral recognized to be psilomelane, the common manganese mineral of the Franciscan formation of the Coast Ranges of California. In the autumn of 1918 when restricted shipping facilities created an urgent demand for domes- tic manganese ores, the city of San Jose, owner of the land on which the bowlder was located, at the request of the government decided to dispose of it. Several hun- dred tons of high-grade manganese ore* was obtained from it and shipped to a California steel plant. My attention was called to the manganese ore of a ‘Alum Rock meteorite,’’ as it was known locally, by a resident of San Jose who presented me with a small specimen from its interior. Great was my surprise to find that this specimen was largely pyrochroite, Mn(OH),, and not psilomelane. As soon as opportunity was afforded, a visit to the locality was made and a suite of specimens obtained. The minerals identified in the bowlder are: Tephroite, hausmannite, pyrochroite, gano- phyllite, rhodochrosite, barite and psilomelane. Of these the first four are very rare, except at Langban, Sweden, and ganophyllite is known only from this locality. Haus- mannite is not certainly known in the United States but has been reported from San Luis Obispo County, California. Pyrochroite occurs at Franklin Furnace, New Jersey. Tephroite in this country has been found in but two localities, Franklin Furnace and central Texas. After the minerals are described, an attempt will be made to determine the relations of the minerals to each other and the character of the deposit. The facts brought out in this discussion may have a bearing on cer- tain geological problems pertaining to the Coast Ranges of California. *'The ore shipped varied in manganese content from 43-2 to 63.5 per cent and averaged 52-6 per cent, according to Dr. W. C. Bailey, City Manager of San Jose, to whom I am indebted for this information. 444 A. F. Rogers—Manganese Minerals. DESCRIPTION OF THE MINERALS. Tephroite-—Tephroite as a megascopic constituent of the ore is rare but in several specimens it was noted as a Massive grayish red mineral which was at first thought to be rhodonite. It lacks, however, the perfect cleavage of rhodonite, a hand lens showing but traces of imperfect cleavage surfaces. It also has a faint resinous luster different from the vitreous luster of rhodonite. The specific gravity of an impure specimen was found by a rough determination to be about 3-75, but carefully selected fragments with only traces of visible impurities gave a specific gravity of 4:010 (determined on 1:5 grams by pyknometer at 25°C.). The tephroite is very easily soluble in dilute HCI with gelatinization and the solution gives an abundant test for manganese and faint tests for iron, calcium, and mag- nesium. The indices of refraction, determined by the immer- sion method, are greater than 1-740. Thin sections show almost colorless anhedra with interference colors rang- ing up to bluish-green of the second order, which proves that the double refraction is higher than that of rhodo- nite (ny-na=— 0-011) but lower than that of olivine (ny- na=—0-036). Polysynthetic twinning is a prominent feature in the thin sections, a property not previously reported for tephroite. In some areas the twinning re- sembles the albite twinning of plagioclase, but more often it resembles an intergrowth of two minerals. The twin- ning is recognized largely by differences in interference colors rather than by extinction angles. Although not often visible in the hand specimens, tephroite in isolated anhedra surrounded by alteration products is seen in many thin sections. For this reason it was probably present in abundance in one stage of the history of the deposit, but on account of its ready altera- tion only remnants of it are left. Hausmannite-—Hausmannite, on the other hand, can be recognized in many of the hand specimens and in some it is by far the most abundant mineral present. It occurs in crystals which vary from euhedral to anhedral, but are usually subhedral. A few small (1 to 2 mm. in size) euhedral crystals were found and prove to have the following forms: (001), (1138), (111), (221), with the unit tetragonal bipyramid (111) as the dominant form. The following measurements were made with the reflection goniometer : A. F. Rogers—Manganese Minerals. 445 Interfacial angles of hausmannite. No. of meas. Meas. Record. (001) A (111) 4 58° 321,’ i}2 Aes 4 (001) A (1138) a 25 0 28 3414 Chir) ACEI) S| (ies ees a ako (001) A (221) it TY °° fo ao In thin sections most of the hausmannite is opaque, but on the edges of the sections some of it is translucent and dark red. A few of the deep red crystals are dark between crossed nicols but most of them are doubly- refracting with definite extinction four times in a revolu- tion. Polysynthetic twinning was noted in some sections. Crushed fragments of the hausmannite examined with the polarizing microscope under ordinary conditions appear opaque, but in direct sunlight between crossed nicols many of them are translucent dark red. (The crossing of the nicols shuts off the brilliant refiection of the sun and so the fragments are visible.) They are doubly-refracting but the color of the mineral masks the interference colors. This method may be of service in determining some of the submetallic minerals which are opaque in ordinary light, provided of course they are doubly refracting. The hausmannite is readily and completely STA in HCl with the evolution of chlorine. Pyrochroite—The pyrochroite occurs in euhedral crystals (up to 5 mm. in size) in cavities and in cleavable plates in masses. The euhedral crystals are thin lentic- ular without well-defined faces. A few are hexagonal in outline with a low vicinal rhombohedron. In most specimens the pyrochroite is a bronze-red but soon changes to black on exposure. Freshly broken speci- mens often show the deep red reflections that give the name to the mineral. In a few eases it is colorless or pale green. It has a perfect cleavage in one direction. The index of refraction of cleavage flakes was found to be ny= 1-733 + -003 (sodium lght) which is a'‘little higher than the recorded value (1-723). One of the cleavage flakes gave a negative uniaxial interference figure in convergent light. In thin sections the pyrochroite is colorless to salmon- colored. The areas without cleavage are non-pleochroic and are either dark between crossed nicols or have very 446 A. F. Rogers—Manganese Mimerals. weak double refraction, while the salmon-colored areas showing cleavage are pleochroic from nearly colorless to deep yellowish-red. The double refraction determined by finding the thickness of a section from the highest interference color of associated barite is about 0-04. The direction of the cleavage traces in thin sections is parallel to the slower ray which checks the optically negative character determined above. The pyrochroite is also soluble in HCl with the evolu- tion of chlorine and gives abundant water in the closed tube. Along cleavage planes the pyrochroite in thin sections is seen to be altered to an opaque brown oxidation product. This is a hydrous manganese oxide of some sort and may possibly be the amorphous equivalent of manganite which represent a higher state of oxidation of manganese than pyrochroite. Rhodochrosite-—Rhodochrosite occurs both in euhedral crystals along seams and in granular masses. ‘The euhe- dral crystals are pink in color and have the form of the negative rhombohedron (0221), a common form for eal- cite, but a very rare one for rhodochrosite. It usually occurs alone, but in a few cases narrow faces of the posi- tive unit rhombohedron (1011) were observed. The rhombohedron (0221) was identified by the fact that the cleavage rhombohedron truncates its polar edges. This was checked by the following measurements made with the simple reflection goniometer devised by the writer :1 0221 A 2021 — 100° cale.=.99° 54”) =. 0221 / 202i (cale. = 80° 6’). | Some of the specimens are made up largely of fine- erained reddish gray rhodochrosite which shows minute cleavage surfaces. A few light reddish gray specimens seem to consist of rhodochrosite and barite. Rhodo- chrosite must be common in many specimens even when not visible to the unaided eye, for they effervesce in hot HCl and thin sections show the presence of a rhombo- hedral carbonate. Ganophyllite--This very rare mineral, heretofore known only at the original locality (Langban, Sweden), was found along seams with cleavable barite as brownish- *Science (n. s.) Vol. 27, p. 929 (1908). This little device constructed out of a Penfield cardboard goniometer often saves the necessity of using the large reflection goniometer when approximate measurements suffice. A. F. Rogers—Manganese Minerals. 447. yellow distorted tabular crystals. It was identified? by the index of refraction m — 1-723 + -003 (recorded values ny—1-730; nS—1-729; «is perpendicular to the plates so that nais not easily obtained). The plates are pale yellow, non-pleochroic and give a biaxial interference figure in convergent light. The optical determination was checked by qualitative tests for aluminum, manga- nese and water. Psilomelane——Massive black and somewhat banded psilomelane makes up the list of manganese minerals that can be positively identified. Before it was broken up to be used as manganese ore, the whole bowlder, or so-called meteorite, was supposed to be psilomelane, but it turns out that only the outside crust is psilomelane. Barite.—Barite seems to be practically the only min- eral of the deposit which does not contain manganese. It occurs in euhedral crystals along seams and in thin sections, and it also proves to be interspersed through many of the specimens. The euhedral barite crystals are of two different habits: (1) highly modified crystals of equant habit, with (110), (111) and (001) as promi- nent forms and (2) crystals of pyramidal habit with the unit bipyramid (111) as the dominant form, a very rare habit for barite. Other minerals—There are a few other minerals which oceur in such small quantities they have not yet been identified. Some of the massive gray specimens are apparently homogeneous but prove on microscopic exam- ination to be microcrystalline aggregates. Mineralog- ical literature is so full of descriptions of so-called new minerals based upon such material that the writer has refrained from an attempt to characterize these sub- stances until better specimens can be obtained. PARAGENESIS OF THE MINERALS.? After the minerals of a rock or mineral deposit have been identified, the next thing to do is to determine the relations of the minerals to each other. This is often a *This determination took only 15 minutes which is a testimony to the value of optical methods in determining minerals in fragments by means of the polarizing microscope. The writer had never seen ganophyllite before and had scarcely heard of the mineral. “By this term I mean the relation of associated minerals, not simply the order of succession, which is only one phase of these relations. ¢ 448 A. F. Rogers—Manganese Minerals. difficult task, but it is equally important with the deter- mination of the minerals. The order of succession of the minerals of this manga- nese deposit is as follows: tephroite, hausmannite, rho- dochrosite, pyrochroite, and psilomelane. The place of barite cannot be fixed definitely, but it seems to be earlier than the rhodochrosite. It probably occurs in several generations. Tephroite is undoubtedly the earliest formed mineral present. It was probably abundant at one stage in the history of the deposit but is now present as residual specks. The alteration products of the tephroite are indefinite, ill-defined substances to which no name can be assigned. Hausmannite, although occurring in euhedral crystals, was probably formed later than the tephroite, for vein- like areas of hausmannite surround and extend into areas of tephroite and there is no evidence of more than one generation of hausmannite. Rhodochrosite is certainly later than the tephroite and hausmannite, for it occurs in veinlets cutting these min- erals. It is often associated with barite and replaces the barite. The pyrochroite is a relatively late mineral, for it occurs as a replacement of hausmannite and is common in euhedral crystals along seams. It is also later than a part at least of the barite. The pyrochroite in turn yields to a brown hydrous manganese oxide which may possibly be the amorphous equivalent of manganite. Finally the psilomelane was formed as a crust on the exterior of the bowlder probably after it was detached from its place of origin. The above order of sequence seems reasonable in view of the fact that most of the minerals show a general increase in the state of oxidation of the manganese from the early to the late stages. In the tephroite we have the manganous state (2MnO.S8i0,) ; in hausmannite, we have an intermediate condition (Mn,O,), and finally in psilo- melane a still higher state of oxidation (MnOQ,). | The bowlder undoubtedly represents a block detached from its original location in the hills above, in some past, probably remote, period. With the exception of the barite it contains no gangue minerals, although lacking A. F. Rogers—Manganese Minerals. 449 in chalcedony and quartz. It is probably of Franciscan age, as are all the other manganese deposits of the Coast Ranges. The occurrence of hausmannite at a mine in San Luis Obispo County* and an undescribed occurrence of tephroite near Mount Diablo both in rocks of Francis- can age gives credence to this belief. Franciscan cherts and jaspers outcrop two to three miles east of the spot in which the bowlder is located. Several manganese de- posits are found here but as far as examined they are different mineralogically from the so-called meteorite. The typical occurrence of tephroite and hausmannite is in contact-metamorphic deposits. No lmestone is present in the vicinity of Alum Rock Canyon and none was found in the bowlder. Limestones of Franciscan age are known at various places in the Coast Ranges but they are unmetamorphosed. Although some doubt is attached to the original occur- rence of this manganese ore, the presence of tephroite and hausmannite points to the high-temperature nature of the deposit. The rhodochrosite is undoubtedly a hydrothermal mineral and the psilomelane doubtless was formed by meteoric waters at a very late period. The pyrochroite is intermediate in age between the rhodo- chrosite and the psilomelane. Was it formed by meteoric waters or by hydrothermal solutions? This question cannot be answered definitely, but it is believed to have been formed at a late hydrothermal stage. It is altered to a later hydrous manganese oxide and so is unstable under oxidizing conditions. In fact specimens alter when exposed for several days. The presence of a large amount of water [Mn(OH),; H,O = 20-3 per cent] is no proof that a mineral is formed by meteoric waters. Such is believed to be the essential history of this interesting deposit or rather remnant of a deposit, though a number of questions can not be settled for lack of sufficient data. The existence of this bowlder makes it probable that some, if not many, of the manganese deposits of the Coast Ranges of California are of high temperature hydrothermal origin. The prevalence of psilomelane may be accounted for by subsequent altera- tion of the hydrothermal minerals by meteoric water. Stanford University, California, September, 1919. * Bull. 76, California State Mining Bureau, p. 14, 1918. 450 M. O’Connell—Orthogenetic Development Arr. XXXII.—Orthogenetic Development of the Coste im the Perisphinctine;' by Marzoriz O’Connetu, Ph.D. The word orthogenesis is derived from the Greek ép60s, straight, and yéveois, production, and means simply devel- opment or variation in a definite direction. There are at present two different conceptions of the meaning of this term, one being that orthogenesis is a fact made known to us by observation, the other that it is a theory to explain observed facts. A few quotations will illus- trate the divergence in thought in these two fundamental concepts of a single term. Eimer, in his paper on ‘Orthogenesis and the Impo- tence of Natural Selection,’ has made a careful distine- tion between the fact and the cause of orthogenesis. He was the first to bring the term into general use and it is, therefore, important to know exactly what he meant by it. He says: ‘‘The translation of definitely directed development (bestimmt gerichtete Entwicklung) into the word ‘orthogenesis’ was first employed by Wilhelm Haacke in his book Gestaltung und Vererbung in 1898, and as it is very expressive, I have adopted it for my own use.’” ‘‘Orthogenesis,’’ Eimer states, ‘‘shows that organisms develop in definite directions without the least regard for utility through purely physiological causes as the result of organic growth.’ Orthogenesis he defines elsewhere as ‘‘the fact that the transmutation of the animal world takes place, not as Darwinism and the advocates, of ‘omnipotent natural selection’ (Weis- mannian Pseudo-Darwinism) assume, accidentally in numerous and even widely diverse directions, but sys- tematically and conformably to law in only a few direc- tions.’’* Eimer not only adduced a wealth of illustration in support of his belief in the universality of the law of orthogenesis, but he attempted to formulate the causes and it was here that he came into conflict with the fol- *This paper is based on material in the collections of the Department of Geology and Invertebrate Paleontology of the American Museum of Natural History and was prepared while the author was an assistant in the department, but the researches were carried on and this paper was written outside of official hours. The material was collected in Cuba by Mr. Barnum Brown of the Museum and is described in a forthcoming PT mee I. H. Theodor, 1898. Orthogenesis and the Impotence of Natural Selection, p. 19. * Loe. cit., p. 2. * Loe. cit., p. 20. of the Coste in the Perisphinctine. 451 lowers of Darwin and Weismann, for he came out strongly against the potency of natural selection in the formation of species, considering it only as a process which ‘‘may remove what is downright injurious’? and ‘may preserve what is useful’’ but which is always sub- ordinate to orthogenesis. Furthermore, he advocated the inheritance of acquired characters as a necessary out- come of the operation of the law of orthogenesis and expressed the belief that ‘‘the causes of definitely directed evolution [1i. e. orthogenesis] are contained. . . in the effects produced by outward circumstances and influences such as climate and nutrition upon the consti- tution of a given organism.’”® It is not our purpose to enter into a discussion of these causes; we are seeking only to discover how the term orthogenesis should be used, and we see that Kimer, who first gave it prominence, distinguished between the law and the causes of orthogenesis or definitely directed evolution. Later authors, however, have usually con- fused the two. Professor Grabau in his ‘Studies of Gastropoda’ has followed Kimer’s usage, regarding orthogenesis as an observable method of development, and he states that: ‘‘Orthogenetic variation may be defined as progressive variation along definite or determinate lines.’’¢ Professor Lull, on the other hand, in his book on ‘Organic Evolution’ says: ‘‘Orthogenesis . . . is the theory that variations and hence evolutionary change occur along certain definite lines impelled by laws of which we know not the cause.’” Finally, Professor Morgan in his ‘Critique of the Theory of Evolution’ in- cludes the unfolding principle as one of the ‘‘four great historical speculations’’ concerning evolution, stating that ‘‘it is little more than a mystic sentiment to the effect that evolution is the result of an inner driving force or principle which goes under many names such as Bildungstrieb, nisus formativus, vital force and ortho- genesis.’’§ From these diverse expressions of opinion it is clear PLiec.) city ip: 22. *Grabau, A. W., 1907. Studies of Gastropoda. On Orthogenetic Varia- tion in Gastropoda, Am. Naturalist, vol. 41, no. 490, p. 607. ‘Lull, R. S., 1917. Organic’ Evolution, p. 175. (Macmillan Company.) “Morgan, T. H., 1916. A Critique of the Theory of Evolution, p. 34. (Princeton University Press.) Am. Jour. Ct aaa SERIES, VoL. XLVIII, No. 288.—Drcemser, 1919. 1 452 MM. O’Connell—Orthogenetic Development that the term orthogenesis has been used by some writers to describe certain observed phenomena and by others to explain the origin of those phenomena. It is for this very reason that so much confusion has arisen and many ‘who cannot see in orthogenesis a cause of evolution deny its existence as a mode of development. If at the outset, then, we distinguish between the fact or law of ortho- genesis and a possible, and as yet undiscovered, cause of orthogenesis, the matter is greatly simplified and we lay claim to nothing but what we can see. It is true that Eimer believes that he has discovered the cause of ortho- genesis, but his statements are open to criticism and there is no question that his data and observations are capable of other interpretations than the ones which he has given. What we cannot deny, however, is that he did bring together many excellent illustrations of the law of orthogenesis whether or not we believe in the expla- nation which he offered. : Considering, then, that orthogenesis is ‘to be applied to facts, to observable phenomena, we must make one further restriction and state that the observations made must be of successive changes, either in the growth of an individual, that is, in ontogeny, or in the evolution of the race, that is, in phylogeny. ‘T'his idea of succession is bound up in the very definition of orthogenesis and must not be lost sight of. There are four fields in which observations may be made to a greater or less extent in carrying on ortho- genetic studies, namely, those of experimental and obser- vational biology, embryology, vertebrate paleontology ~ and invertebrate paleontology. It-is at once apparent from our restricted definition of orthogenesis that the zoologist seldom has the facts of orthogenesis presented to him in his studies, for he deals with individual adults, in which he sees only single isolated stages in the ontogeny, and he deals with living forms, having thus nothing to do with phylogeny, except in so far as this is presented in a single chronofauna. The experimental zoologist, or genetecist, concerns him- self neither with successive changes in the development of the individual nor with the changes through geologic time in species, genera or phyla and he, therefore, never has presented to him the data for orthogenetic studies. The observational biologist may, to a limited degree, of the Coste in the Perisphinctine. £08 observe phyletic trends when he considers a species in its geographic distribution or studies the variations in different characters in successive generations through- out a period of years. In the case of geographic distri- bution, if the zoologist starts from a given center of distribution and is able to follow out in unbroken lines the variations which arise in passing from the point of origin to provinces successively further removed, then he may, and theoretically should, observe orthogenetic changes. The practical difficulty frequently presents itself of determining to his own and others’ satisfaction what was the center of distribution and which was the fundamental primitive species whence the numerous adaptively radiating variations were derived. In the study of determinate variations in a single species the zoologist probably has his best opportunity to see the facts of orthogenesis. As an instance of this method of approach may be cited the observations made by Kellogg and Bell on the flower beetle, Diabrotica soror, collected from the campus of Leland Stanford University. Series of a thousand individuals each were studied and their variations over a period of seven years were recorded and it was found that in that time there had been a very definite change in the prevalence of one type of color pattern on the wings over another. In such a case as this the zoologist, while seeing nothing of ontogeny, yet has the advantage of the time element which is essential in the study of phylogeny, but the time at his disposal is so short that he can observe only comparatively insignif- icant variations in characters sufficiently mutable to ~ show a recognizable change during a period which must, after all, be considered as only an instant when compared with the hundreds of millions of years during which evolution has been producing the complex types which the zoologist observes. Yet, however small such varia- tions are, if they show a definite direction the fact of orthogenesis is clearly demonstrated. Obviously the facts of phylogeny as a whole or even in any appreciable amount are never visible to the zoologist who is mortal. The embryologist likewise is cut off from the broad facts of phylogeny because he must of necessity deal with living forms. Furthermore, although he has before him the entire ontogeny of the individuals of the present, he, as a rule, elects to look at only the embryonic stages, 454 M. O’Connell—Orthogenetic Development passing over as of little or no importance the complete epembryonic development. It is true that the embryolo- gist sees successive changes in growth and that he can make certain general comparisons, but, as is well known, the history which he reads is so abbreviated, so many chapters are lost through condensation and elimination, that he catches but an evanescent glimpse of this or that ancestral condition as the pages pass rapidly before his gaze. Furthermore, he makes his comparison not so much between entire embryos of various types, as between the different organs of embryos higher or lower in the scale of hfe. Thus he traces the homologies of the fore-limbs in the embryo of a bird, the bat and man, he finds that the heart in mammals in the course of its embryonic development passes through fish, amphibian and reptilian stages, but in these and all similar cases comparisons are made between stages of development of organs not organisms and the recapitulation observed is so general that we see the same kind of embryonic suc- cession in all mammals, for instance, with variations produced more by what is left out of the history than by what is added, for each organism, if it could give a com- plete recapitulation of its ancestral characters, would have to show all that the paleontologist already knows and all that he hopes to know as well as what he never will know. Therefore, in any given embryo we see a few | selected pages, but it is clear that orthogenetic trends will be entirely obscured, since such directions are seen in individuals, in species, in genera but not when we pass from phylum to phylum, from fish to reptile, to amphi- bian, to mammal. The third field open for orthogenetic studies is that of vertebrate paleontology. Here one may observe succes- sive changes in time and may work out evolutionary series which in many cases show orthogenesis or, as Professor Grabau has called it, ortho-phylogeny, in con- tradistinction to ortho-ontogeny. As a rule the verte- brate paleontologist deals with adult individuals and for any species he may know nothing of the young and sub-mature stages of development. In other words, he may arrange an entire phyletic series without knowing anything about the ontogeny of the species in that series. A knowledge of the ontogeny must always be fortuitous, depending upon the finding in a single place of a large of the Coste in the Perisphinctine. 455 number of skeletons ranging in age from young to adult but all representing one species. Kven in such a rare and happy case there is no proof that the young indi- viduals are actually the immature forms of the adults found in the same place, however perfect a gradation in characters and proportions may be shown in the speci- mens, for parallelism in the development of genetically unrelated species may so obscure the true diversity in origin that an ideal series may be arranged which unfor- tunately has no other value than its diagrammatic clear- ness. It is even worse when the young individuals of a species are found in a locality at some distance from that where the adults occur. When we consider the vicissitudes attending the preservation of vertebrates, particularly terrestrial and aerial forms, when we think of the many groups which must at all times have been branching off from the main lines and have been develop- ing progressively and retrogressively with changing proportions and newly appearing characters, the chances are rather against there being any necessary genetic relationship between a young individual found at one locality and an adult found at some distance, even if at the same horizon. With organic and inorganic factors working, it would seem, for the very purpose of obscur- ing genetic relations, the vertebrate paleontologist cer- tainly has no enviable task in trying to decipher ontogeny. We see, then, that in this field the illustrations of ortho- genesis must be sought almost wholly in phylogeny and it is here that we find such celebrated series as those of the horse, the elephant and the titanotheres. Yet is it not true that in all of these cases there are elements of doubt? We may not go so far as does Professor Morgan who says that the paleontologist chooses to arrange his specimens in certain series, but that they might just as well be arranged in some altogether different fashion. Thus, Professor Morgan has obtained in a single genera- tion of flies what appears to be a perfect orthogenetic gradation of eye color which makes a good series with every transition shown from white to red and yet this is due simply to certain slight differences in the chromo- somes which produce in a single batch of flies variations indicating no definite direction in development such as a paleontologist would think he had if he found a series showing similar slight gradations in a given character. 456 M. O’Connell—Orthogenetic Development We will not go so far, I say, as to agree with Professor Morgan that the vertebrate paleontologist could juggle his specimens and arrange them to show anything he desired to, but we must admit, I think, that there are many chances to go wrong when one makes up a genetic series, say from a dozen adult specimens occurring from Hocenic time to the Pleistocenic, and that even if these dozen individuals show certain definite trends in develop- ment such as the increase in length of a horn, the loss of a toe, the addition of cusps on the teeth, there will al- ways remain the question: are not these dozen speci- mens simply individuals belonging to many lines, some of which may even have become extinct, and do they not give a general picture of the kind of development of the - race as a whole rather than a genetic series? For instance, Professor Osborn has pointed out that in the titanotheres the actual continuity of the series ‘‘is broken by the extinction of one branch and survival of another. It is a continuity of character rather than of lines of descent.’” If we turn to the fourth field of orthogenetic study, that of invertebrate paleontology, we find that both phylogeny and ontogeny are available in most cases. It is true that the ontogeny of the crustacea and certain smaller groups is nearly as difficult to study as that of the vertebrates, because the individuals do not retain the record of their early developmental stages, but in the molluses, corals and brachiopods, the shell or other hard structure preserves the complete record of the life his- tory of the individual from the earliest epembryonic stage to the time of the death of the animal, which was normally in late maturity or old age. In many eases, where the material is well preserved, one may even see the last embryonic stage, so that one may enter, if only a short way, into the field of the embryologist. The invertebrate paleontologist is also fortunate in having large numbers of individuals of a single species to study. He may collect literally a thousand specimens of one species at a given spot and horizon, and then he may col- lect at successive horizons, going upward inch by inch collecting quantities in each stratum and thus he may work out with a certainty hardly to be questioned what was the nature of the changes which took place in that * Osborn, H. F.: Origin and Evolution of Life, p. 264. of the Coste in the Perisphinctine. ieee oy species at each level, that is, what varieties arose (in the Waagen sense), and he may trace also the changes in time from level to level, that is the mutations. In addition to these geographic and geologic data in phylogeny he has the entire life history of each individ- ual so that he may pass from the details of ontogeny to the generalities of phylogeny in accordance with the law of recapitulation. But this law of recapitulation has to the invertebrate paleontologist a very different meaning from that which it has to the embryologist and zoologist as Hyatt, Jackson, Smith, Grabau and others have shown. The embryologist finds that there is a gen- eral similarity between the adults of certain lower forms and the embryonic stages of higher forms in living organisms, but the invertebrate paleontologist compares the entire epembryonic development or the stages between the embryo and the adult step by step with the adults in earlier geologic horizons, finding in the life history of a single individual an epitome not alone of the development of the genus, but of the entire phylum. These differences in the viewpoint of the law of recapitu- lation are well known, I merely repeat them here because as we understand recapitulation so do we understand orthogenesis. The invertebrate paleontologist ever ap- proaches ortho-phylogeny in the light and under the guidance of ortho-ontogeny, dealing with the minute changes in the life history of the individual and at most. arguing for orthogenetic development in a single phylum, as in corals or ammonites, but never invoking it to cover the method of development from one phylum into another. Of all the invertebrates the ammonites offer, perhaps, the best opportunities for orthogenetic studies because of their abundance, their comparatively rapid evolution, their complexity in ‘structure, involving as it does a large number of variable characters, and their mode of growth. Because of the coiling of the ammonite shell the early stages are always accessible in well-preserved material, and by separating off the successively earlier and earlier whorls one may ascertain what were the various steps . in the life history of any single individual. One may thus follow out the entire ontogeny and from this one may, with reasonable certainty, predict what was the phylogeny of the genus or family to which the species under study Eelpuser | 458 M. O’Connell—Orthogenetic Development I have taken a single species among the ammonites and have studied the ontogeny in a single specimen. The species is a new one and belongs to the Jurassic ammo- nite fauna of Cuba collected by Mr. Barnum Brown and now in the American Museum of Natural History. The holotype of the species, Perisphinctes cubanensis O’Con- nell, shows orthogenetic development in several shell characters, but I have selected as the most striking illus- tration that of the development of the coste. The entire method of growth of the cost will be discussed in a forthcoming paper, but the particular illustration of orthogenesis is amply shown on the last two whorls of the holotype. The coste are arranged in groups of three which consist of one long costa extending from dorsum to venter of the whorl and two short coste which extend across the venter and about a third of the way dorsad on the whorl. A generic characteristic of Perisphinctes: is the presence, at repeated intervals on the conch, of constrictions or grooves which appear as interruptions to the normal costal arrangement. In Perisphinctes cubanensis there are from three to five groups of cost between every two constrictions or sphincters (S. in fig. 1). In each intersphincterial sector of the shell the coste show a progressive mode of development, each group of three coste being a little in advance in two characters over that just preceding. The simplest arrangement of the three coste consists of a long costa extending from venter to dorsum, a short one attached to the long one and the third branching off from the first at a point slightly lower than the point of attachment of the second costa; the second and third coste are of equal strength and both are weaker than and not so thick as the first. Uhis primitive condition is shown in the earlier whorls of the species and is very nearly ap- proached in the first triad illustrated in fig. 1 where, however, the third costa is slightly separated from the first. Starting with this primitive costal grouping the second set of three (fig. 1) shows the greatest strength in the second costa with the first and third of equal strength and both attached to the second costa and bend- ing towards it, one forward the other backward, so that the three appear likes the tines of a fork. The next group of three shows the greatest strength still in the second costa, the first being now separated off as a free of the Coste wm the Pertsphinctine. 459 costa while the third is still attached. The fourth group shows the strength in the third costa, one free and two directed towards three. The coste at this point are in- terrupted by a constriction beyond which the costal arrangement instead of continuing the trend shown in the preceding intersphincterial sector shows a retrogres- sion. But the first triad of costae does not show the same Hie.) i. VEIN'TE.R & TET 71 HLL aco DORSUM Fig. 1—Arrangement of coste on last half of fifth volution of the holotype of Perisphinctes cubanensis O’Connell. S. constriction or sphincter marking interruption in regular costal development. —-——— Fig. 2. | R <—APICAD sa = ORAD > ies. Uae eh ih Si a os DORSUM Fic. 2.—Arrangement of coste in early part of sixth volution of the holotype of Perisphinctes cubanensis O’Connell. 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(Write for a specimen number.) ~Annual Subscription: ; % ogee sh. 6, post free. : _. . Office: Via Aurelio Saffi, 11- MILAN (Italy). CONTENTS. ART. XXVIL Phe Middle Ordévicwn ot Central and South S - Central Pennsylvania; by R. M. Frexp. ne he 408 Arr. XXVIII.—Note on an Unusual Method of 1 Rounding of - cet Pebbles in sub-arid Western Australia; by J. ibs JT UTSON S29 ‘Arr. X XITX.—Sheet- flows, or Sheet-floods, and their: asso- + ciated phenomena in the Niagara District of sub- aos south-central Western Australia; by J.T. Jurson: 80 | Arr. XXX.—Cacoclasite from Wakefield, Cees ‘yy, Th 6 BO WH NG Dasa ete ir Pet ate ae 480 Arr. XXXI,—An fietane ea of Manganese Mins yee erals near San Jose, Californi ; by A. F. Roaurs. 443 : Art. XXXII.—Orthogenetic Development of the nae ince the Perisphinctine ; by Marsorty O’ CONNELL, Ph. Dey. 450) Arr. XXXIIT.—Heterolasma foerstei, a New Genus. cod. Species of Tetracoralla from the Niagaran of Michigan; _ eet Dy, Cost Gee Se ota Mi rp 5 ue pain Shee ree eal tah: Rob ge? 461 . SCIENTIFIC INTELLIGENCE. ee ae ' Chemistry and Physics—Determination of Zirconium by iis Phouphwies Method, . _G. E. F. Lunpswu and H. B. Knowuss, 467,—An Introductory Course in Quantitative Chemical Analysis, G. McP. SmitH, 468,—Richter’s Organic | Chemistry, P. E. Spizr~tmann: Notes on Qualitative Analysis, L. A. Test | and H. M. .\. cLaveuuin, 469.—The Chemistry and Manufacture of Hydro- gen, P. L. TEED: Calculation of the Radiation Constants c, and o, F. HEN- nine, 470.—Indices of Refraction for X-Rays, A. Ernsrmin, 471.—The General Polarization Surface, F, JENTZSCH- pier 472. — Aviation, B, M. CARMINA : Molecular Physies, Second Edition, J. A. CROWTHER, 473. Geology and Natural History—Western, Keaetnates Geological Survey, B: , BLATCHFORD, etc. : New Zealand Institute Science Congress, Christchurch, | | 1919, 474. —Descriptions and Revisions of the Cretaceous and Tertiary Aale wend Fish- Remains of New Zealand, F. Coapman: The Prickly Pear in Austra- — lia, W. B. ALExanpDER, 475. —United: States Geological Survey, G. O. | SMITH, 476.—Foliation and Metamorphism in Rocks, T. G. BONNEY; — Observations on Living Lamellibranchs of New England, E. 8. Morse: Elementary Biology ; An Introduction to the Science of Life, B. C. ney BERG, 477. Miscellaneous Scientific Intelligence —National Academy of Sciences, 478. Obituary—J. W. H. Trait: OC. G. Hopkins: C. H. Hrrexcock, 478. InDEX, 479. , a Bere ee ee a i i. ae oh) ih vie it ’ ¥ i Kn ses sara nl Mea, ca Fie aN a ah fleet és My : arnt Ge . a oiaea. ats i yore a ne iN a i (= Vesna. SET. fe, OBE = res eee a Wise 2y Sy Was = OS, 4 fas & eh Pa ae ae bs eer! Sees ae Se we é agin ae “S A, Peet we! I ie 4 pcos eh Enh HERS qk ras ESN | SS He witout’ “raat ay « Peay FasL iN ae en 7 3 : a als a th myth eat, son : UP Twar ts aartty “Siena ae ft PEWS, fume) eee A ? nh Winrar TLDs Ort fists firey) oe Lu) LAs bas! a Se ae s ood ane” 3 Ss oe eee aS + aia oo I ats cet EE SY #2 ARE. gtr 13 fees Sea ia ae al ae Pst af Af oD e. precy Fide oe us ‘cua LL. ‘oa Nee ted, se Ve ee fos SMITHSONIAN INSTITUTION LIBRARIES 3 9088 01298 600 es Us¢xmetirae wae dcr ta els