4 ear pir vite — ° Martie ibe kent treater nthe : 44 ~ pte th tind 7 nergigty teres wee ee ehorursnarettsetery re 4 TP 4 ¥ ay | ~* bahia die bof Fe? y i ee ee oie an oe pee " ? + . . shar ere! PTO WRENS WRG wae WEN WA Tigh) ee what wie Gi : 4 ; iyi ‘ , " SRT Ne wie 'e winrar aie the ” - ietyte? Lite eon Cee Donn an ols ( wid “ ‘w Deda dail er rane nwhe® ' , ; Petabere le Paseealahgteiaie aig wate te prerelelererere v'¥"8 hh dhs tht hth dilate dtd Uh de tek ee eon Bd ea! Wieiwrete a ; : Led dito PE ee ew Fale Stureele wel ety Pee Se a at ‘y bith ted 2 ae oO Te ek wwin's Ok ewe ep wg ais ie) SEC ww ere rete PR ee ee ety “Ee ewe SPV Ew eer re er SIT ew yt eee ere TiN yy Sew ialyt firth APA tn ty fan me A Bee a pO . & PS es oe. Py ed Sy ~~ —-™ aime « = as Mote mi +N id 44 or | en ~al ; aa pow’ Ow! 1 sch eu Pia] - a Ne / basd se , % pte a4 de , Whe x one ‘ eo. ‘ : Nn ar” aw ‘~* reas bere ate ¢ % ere ym eat v~ ee Pr tk DAP Niel al is Og Ke ie BS fet Somes Bor WEL reve anys ya Pr hh Dn ate: a NON MRS Aweg Se hs os Wteeeeet® ll) - pe ee Ais iy Trt tI Pk : Ananth x 1 alg 1 C¢ @ Ary "er! Pais ow "TIRAAS tty pAnnn w ~ Py ALANA A voor a ef did PAL ny Peers uneeanee a Hi hit | NEL LTEE Nana Sei Tey ar ‘Fue we A. HU li gaa vente a flak Ty. ONIN Ph Liuaw ae 1 reat it ELLE HE Tae et keg veges ui *&y wh! = iy wa TAS RAAAA OA jay a j Ae! % Muy NKuky gn a . ee Sp { ~# ee \ = e: A gf" SAA. antl ay Ls wus fe PS yap ty vN View: ta Ma ct KR & ig wea wey et ~ wr SNL Nt HARA pall | LF WSU TETLitem yet seatige Weg tts : ea ha Ne ‘ oe aw A WUE bY) a wa, mars wey ‘“ ty wh: ti aT wf Raid gp) bu | pera My Ts wit Maske s we Mea ae ok MAT “ ; PY y Aes Nie HV; 4 SN w Seen UN vt AS VWe Ay RAS Wye re AL “¢ a. 2 | vy 4 { eo aes ~ i; eee e 7 ° ~~ =. Wh afin sas Ch beeen NA oe Mia hai | baa | UU arta ste "8 | DIOP us Pg Set o~ aN y i al WL Ww oT ct“ we cies SH ae * li ¥ + TTT Sahu, TTT. MAR sicieha Sh AMIE Ss re 4 vl y 1 yr ee a Nee tems WE Cus OT ol ae . To wit ex hb iG Ay A Sh bs fe. ‘ 7} | Vey > wth" Ma Lh ¥ Saerne” ee : ws < wre ‘e wo vv Pr wip” é ncaa Wr ean | {HL WE Sane ST seat budddeas cet dyrtst Ve vA w i 1 : LA “ah Ot weir we AY Fh. wr wvig | a tN -@ ry “ye 8 wm Veet aes te » wget oe \ & \ ‘ ww Y by J : re ~ Vet \ lee . Aer te Te te sll ante. te lie oe CUCET OE wy , woe ae RR ME if Se wey) Me ae ne bear : ee a “AW i + a te rabei e and A sqm, me: "degy. eh. ANS kL ARS AN ie | he, ff RIMM a tit pe AA eNige e Riis be PULA MP aa A iT Vin J- Wain - a Wty } mr, j ae ‘ AMT ait ONS Aa o rr *4aL, | =n AAI W4gae4 42? aye WEI. abehA Ane WON ten Hapeape® Agitreeets “fi a! %> comratt POO ON" 4 Se An URC v ay te 48 Watven pier | ~ bly cde oR RG gtiee eee <4 Val : 1 os ne move Tidbed Dade bid 4y Sai AT eS 4 tA Ne! ~) tt wve Lye’ Vogduay ’ RY ae SM pd a perl! ha Ut Op C OANA ) wil i WY VHA, att ti? ase A ak VR EEE Iie eee ¥ pot “hiNebiig Lh po dH: i egded® Awe Kewes We nf Mews re hd ” Anan?” ae fy | penal endt sdk aught WW" Aadays teas SNpe praetor, “a oat ote oem 1 : ~o sal AS = | | PLE LLL Ue ELSE an mee a -f ~ AA, wa RNA a Jor Anan oly a j ? vi i , a Me r id ew eel Woes Ae Je. jo gata tt Ad eA: - \ e-F fe — SB, ‘Fo par J>ORye * Pi TPO ay MR oh | | 1 eNO oo | | aby nda ° -s ae rs LA “a : iy wy i J i ae {| Wercah Tortlr Hate ag geen Sterile alinnnttt ji 7 Ligh os nem, ~m | | . Arr. XI.—A Solution of the Aurora Problem; by Prof. | FRANK H. BiGELow. THE problem of the Aurora to which reference is made, is the question of the location in space of the visible arch and streamers, referred to the surface of the earth, as seen by an observer. ‘This is becoming a matter of more importance than it once was, because the progress of discovery shows that it is one of the indices of the physical connection between the sun and the earth, as communicated through the medium of the ether. It therefore holds the same relative position that light and heat do to meteorological phenomena, or that induction does to magnetic variations. But it has the peculiarity of marking out the paths of the magnetic and electric forces that enter or depart from the earth, for it will be assumed that observations have already settled the fact that the auroral streamers coincide with the direction of the lines of force sur- rounding the earth, considered as a magnet. If there are any variations from this condition, it will be one of our ultimate objects to discover them, and perhaps the laws governing the same. At present, however, we limit ourselves to the simple case of the problem, namely the heights, and the distance of a ray from the observer. J am sorry to say that, so far as my knowledge extends, after a diligent search, there are no obser- vations on record of the right form, that will enable me to test the theory. It is my object in this paper to explain the solution, and a simple piece of apparatus, in hopes that before long a suitable set of measurements may be made. Am. Jour. Sc1.—THIRD SERIES, VoL. XLI, No. 242.—FEBRUARY, 1891. 6 84. F.. H. Bigelow—Solution of the Aurora Problem. The methods of obtaining the heights of auroras hitherto given have afforded very discordant results, and a brief inspec- tion shows that one or more terms of the problem have been assumed, which of course implies the discordant results men- tioned. In my analysis there is one assumption at the begin- ning, but it is checked by the measurements, so that we resort in effect to a solution by trial and error. Auroral heights have been treated in several ways, (1) by parallax from two stations near the same meridian, the distance between the stations being known; (2) by observing a distinguishing point from two stations on different meridians, to determine the height and the azimuth of the point of vision; (8) by certain meas- ures from one station; (4) by comparing with the height of neighboring objects. The results for height range from 75™ to 1600*", in fact from the ground to the limits of the atmo- sphere. One general criticism applies to all these methods, that observers are not sure of seeing the same point continu- ously at one station, or of seeing the same point at all from different stations. M. Biese and M. Pétrélius, near Sodankyla, were stationed 4°5 miles apart in the same meridian, being con- nected by a telephone line. Having arranged to observe the same object simultaneously, Biese sent this message, “ fix the line where the red ray is found ;”’ at the other station no red ray could be seen. Nordenskidld’s solution rests upon an hypothesis regarding the position of the center of the visible auroral circle above the surface of the earth. He measures the apparent altitude of the center of the arch (7), the amplitude of the arch on the horizon (28), and assumes the angle at the center of the earth between the station and the radius to the center of the visible circle. Hornstein assumes the angle at the center of the earth between the radius to one of two stations on the same meridian, and the radius extending to the point of measurement, which, as In the former case, is the same as assuming the distance from the observer to the given point. Newton assumes the distance from the observer to the center of curvature of the nearest part of the belt of the maximum number of auroras, which amounts to referring the phenomenon seen to the mag- netic system of the earth. His solution relates only to the arches, but I shall show how with an assumption similar to his we may utilize the streamers, as distinguished from the arches, supposing those to lie in the lines of the magnetic field sur- rounding the earth. The observations required consist in measuring the angle of inclination of a streamer to the vertical plane passing.through the station, together with the azimuth of the ray, prolonged if necessary, at the point of its springing from the horizon. An F.. H. Bigelow—Solution of the Aurora Problem. 85 instrument can be readily constructed for this purpose. A horizontal circle for azimuth, ik levelled, the zero reading be- ing set to the North geographic pole, carries a vertical are graduated + 90°; the zero being at the top. At the center of this semicircle swings a bar having one edge straight, marked off with a linear scale. The sight line is on the diam- eter of the azimuth circle that pierces the center of the ver- tical semicircle, and may be simply a couple of diaphragms. The observation is made by turning the straight edge into such a position that it will lie parallel to the axis of a ray, or any other line to be meas- ured, reading the top and _ bot- tom of the visible ray on the divisions of the linear scale, which gives the angular dis- Fig. 1.—General plan of an apparatus tance of the same from the for measuring the inclination of a ray to point of disappearance of the the vertical. ray as it passes the horizon; also reading the angle on the semicircle at which the arm is inclined from the vertical; and the azimuth on the horizontal circle of the point at which the ray touches the horizon. Such an observation can be made very quickly, even so as to take the rapid flashes of the vibrat- ing auroras. ‘The more inclined the rays from the vertical the more valuable the observation, and if the ends of the arch show streamers also visible at the horizon, they will be those especially desirable to secure. In the following solution we shall utilize the equation, cotan l= 2cot@ =2tanm, which was explained in my paper on the Corona (this Journal, Nov., 1890), the notation being, 7, 0, the coordinates of any point on the curve whose equation is, 82 Sin’ N — oa ; ¢the angle that the line of force makes with the radius to the point, and m the angle that the circle-tangent makes with the polar axis of reference. We take as the polar axis the radius that passes through the magnetic poles, which would be accurate if the potential were uniformly distributed in the earth considered as a magnet, but actually to that point of the surface to which the ray really belongs, as referred to 86 EF. HL. Bigelow—Solution of the Aurora Problem. the existing non-homogeneous distribution. It may be hoped that an accumulation of the observations proposed will throw some light upon the pole of reference, as distinguished from the principal magnetic pole. | Pass a plane through the station of observation, tangent to the sphere at A, intersecting the magnetic pole of reference 2 extended in B, and the aurora ray in B C, the triangle A B C, being there- | fore in the tangent plane. Draw AD at right angles to AB. Now if planes be passed through these lines and the center of the sphere, the traces of intersection of the planes with the surface of the earth are as follows : the trace of AB is AP, cs c¢ DB 66 Diz 66 6G AC Ge AK Connect the center of the sphere with A, B, C and D; OC pierces the sphere at F. . Let the ray spring from the sphere at E, and reach the horizon plane at C, the visible portion being CH, upon which the measurements are made. Since a ray of given polar distance 0, has a given inclina- Y tion to the perpendicular to the Fig. 2.—Showing the relation tangent plane at C, by measuring of a ray with respect to the the angle and interpreting it as pro- hore ane jected on a plane perpendicular to the line of vision AC, we have the means of describing its location in space. For of all the lines of force of similar reference that the line of vision passes, there is only one that ean have the inclination due to a ray at the distance AC. This can be easily perceived by considering these lines around a sphere. Hence by standing at A the only question is how far along the line AC must one go to meet the ray whose angle, corrected for projection, will correspond with the one that is measured. The critical angle of our theorem is therefore at B, namely ABO, on the tangent plane, or the equivalent AOC, at the center of the sphere. If we assume AOC and compute thence to the measured angle, as will be explained, and find the values to be the equal, we have chosen the correct value of AOC. Thus by trial and error, may be found the true angle, and the distance of the point C from the observer. EF. H. Bigelow—Solution of the Aurora Problem. 87 Let « = polar distance of station A to the pole P. “ »=angular distance from station to the point D on the plane. ‘* w= angular distance from station to the point C. The ray lies in the plane, O, PEFD. Dvn?) AB=rtanu. tan B= tan v cot. In the triangle ABO, A = the measured azimuth from magnetic meridian. Gb == Tata myer B = the value obtained by assuming v. Compute, 6 = distance of observer to base of ray on horizon. C= 180 —(A+B), which varies with »v. b=csin B cosee C =r tan w. OC =r sec w. KFC =r secw—r =r(sec w —1), the height of C above the surface of the earth, measured along a radius. At C this radius makes with the perpendicular to the plane, the angle w, lying in the vertical plane AOC. Furthermore in the plane triangle BOC, we have, OB=7rsecu'=c, OC == scr) = 6. BC =a may be computed from the formula, e.sinA C= ‘sin(A +B) : Hence tang0'= y De ) 6’ being the angle BOC, or the magnetic polar distance of the point C on the ray. Now we have by Gauss’ Theorem, Zeond == cov: where / is the angle that the ray at the point C makes with the radius of the earth to that point. This is the angle which is seen by the observer in its projected position. _if we assume the true length in space of the measured por- tion of the ray to be s, we have by fig. 3, the projections of s on the radius CK, and CI at right angles to the radius in the plane of the ray, Cie — scosi. Ol = sisin ¢, The projection of OK on CN the normal to the plane, drawn at the point C, is CM=scos/cosw; and of CI on CL per- pendicular to CA, is CL = ssin/7sin (A+B). Therefore, rep- resenting by 4A the difference in azimuth of the two points of the ray, and by 4h the difference in altitude of the same, we find, 88 fF. H. Bigelow—Solution of the Aurora Problem. s sin/sin(A+B) ==, scos/cosw == : HA ieX tan /sin (A+B) sec w = We Since the left hand number of this equation is derived from theory, with the help of one assumed angle, and the right hand member comes from observation, we have a test of the correctness of our assumed angle. By trial and error, or using this as an equation of condition, we can arrive at the true angles involved. Fig. 3.—Showing the projection of the ray upon the reference plane. We have now found the true value of 7’, &’, for a point C on the ray, and hence the order, N, is given by 87 sin?’ pes N==.—. Then we may change from 7’ to 7 = 1, at the surface of the ground, and get the angular distance of @ from the magnetic pole, by 3N 0 — 87 For the height of C above the ground, we take 7’—r cos (6’— 9), measured on the radius 7’. W. P. Headden—Oolumbite and Tantalite. 89 I have used simply an orthogonal projection as the easiest to illustrate the theory, but obviously the vanishing point may be placed at A, and the necessary modification introduced into the formule. It may be remarked that since the visible distance of an aurora can be estimated within narrow limits, as it must be closely related to the latitude of the station, it will not be difficult to make the first assumption of the angle within easy range for computing. The change in the value of v is really a variation of the distance of the ray from the observer, and it is this quantity that has been so difficult to secure. Having onee derived this distance correctly, a whole series of problems lie ready for discussion, as arising in meteorology and terres- trial magnetism. I have shown in a recent paper that the coronal action of the sun arises from a potential of the magnetic type, and from magnetic observations it has been found that this influence is felt at the distance of the earth from the sun, as indicated by the responsive display of auroras after some outburst of the solar energy. It is to be hoped that this disturbance may be traced in the auroral lines, by their inductive displacement in the upper regions, though it may be too small a quantity to be detected by the observations. The whole subject of cosmical interaction of the sun and the earth, through the medium of the ether is so important, that this question of the aurora is one of vital significance, from its connection with it. I there- fore venture to appeal to observers to make such observations of the auroral rays as I have indicated. My only apology for presenting the theory without experimental evidence is the fact that these measurements do not exist, although there is no reason to suppose they will be very difficult to make, and they will undoubtedly be interesting in future discussions of the subject: Art. XII.—Columbite and Tantalite from the Black [Hills of South Dakota ; by W. P. HEADDEN.* 1. CoLUMBITE. THE occurrence of columbite in the Black Hills was first noticed by Prof. W. P. Blake in 1884.+ The localities then known were the Etta and Bob Ingersoll mines, in Pennington Co., S. D., and within a few miles of each other. Since that time the mineral has been found at a number of localities in * The larger part of this article was read before the Colorado Scientific Society, Aug. 4th, 1890. + This Journal, xxviii, 340, 1884, 90 W. P. Headden—Columbite and Tantalite. the same county, and also in the Nigger Hill district in Law- rence Co. It is found with all of the stream tin, very sparing- ly, however, in that from Two Bit and Mace gulches in the Nigger Hill or northern district. Its presence with the stream tin suggests its possible association with the cassiterite in the veins whence the stream tin has been derived. This inference is only partially correct. The columbite is not always associ- ated with the cassiterite, but J have found no columbite where cassiterite did not occur in the same vein—sometimes, but not always, intimately associated with it. The chief occurrence of columbite in the Black Hills is at the Etta mine. It is abundant in the upper part of the open work on the southwestern and southern sides of the hill, where it occurs in a zone of beryl. In other parts of the mine it is associated with spodumene, feldspar,.and sometimes quartz. The line between the beryl and the tin ore, which in this case is a mixture of albite and muscovite, carrying an almost black cassiterite, is sharply defined. Sometimes there is an intervening band of pink feldspar, the mass of which is formed of radiating plates, and has a well defined but undulating and jagged upper boundary. This feldspar is probably an altera- tion product, as is suggested by its mode of occurrence and by the fact that the small spodumene crystals which occasionally occur in this association, have undergone complete change. The columbite occurring here is, in a general way, confined to the beryl, the crystals standing with one end upon or even pene- trating the tin ore, while the crystals themselves are imbedded in the massive beryl. The individual crystals are comparatively small, crowded together, and often penetrate one another. This is not true, however, of other parts of the mine, where the crystals occur of larger size, but as isolated individuals or form- ing groups of afew crystals. The largest individual -erystal in my possession weighs 14 pounds, and the largest group, con- sisting of two and a part of a third crystal, weighs 304 pounds. The Peerless mine, about half a mile north of the Etta, has furnished but one or two larger aggregates of crystals and a few thin plates which occur in the interstices of the quartz masses. One of these larger masses was found on the surface, where the weathering away of the granite had probably left it. The largest mass of which I have personal knowledge occurs in the Sarah mine, about one-quarter mile northwest of the Etta. The section of this mass as it is exposed is 8 in. X 14 in. I could obtain no information as to how much has already been removed, and there is no exposure showing how far the rem- nant extends into the enclosing rock mass. This is the only specimen which I could find in the mine; there is, however, not much work done at this point. W. P.. Headden—Oolumbite and Tantalite. 91 On the Newton lode it occurs very sparingly in thin plates, associated with beryl, which occurs disseminated through the granite in individual crystals from an inch to one and a half inches in diameter and several inches in length. Both the occurrence and the association of these minerals in the Newton ‘lode are entirely different from that of the Etta mine. The only piece of columbite found at the Bob Ingersoll mine has been described by Prof. W. P. Blake, who estimated its original weight to be 2,000 pounds. At the time of my visit to this locality only a small portion of this mass remained, it having been broken to pieces and carried away or cached. I obtained some smaller pieces, varying in weight up to thirty pounds; such a piece is now in the cabinet of the Dakota School of Mines. The mineral occurs in small crystals, and sparingly at the other localities which I have visited in the southern sec- tion, and the same may be said of the northern section of the Hills. No measurements have been made on any of the crystals, and the description here given may need subsequent alteration. Well terminated crystals are rare and usually small. The best and indeed almost the only fair crystals obtained are from the beryl which occurs in the Etta mine, but I have in one speci- men, from an unknown locality, two clusters of several crystals each, in which the crystals are well terminated. The erystals occurring in the Etta mine vary greatly in luster, and also in their modifications. The usual form is tabular, the crystals beg sometimes two inches wide, two or more inches long, and not exceeding one-quarter of an inch in thickness. The terminations of such crystals are always poor. The sur- faces recognized on such are: 010, 110, 180, 100, 1382, 102, 001, 031. These forms are not recognizable on all of the crys- tals ; sometimes the prism 130, and sometimes both prisms are wanting. The crystals are often thinner at one edge than at the other, and are otherwise distorted; they are sometimes vertically, again irregularly, and even horizontally striated. The strize on the Etta crystals do not appear to be due to polysynthetic crys- tallization. The luster on the different surfaces is not equally bright; that of the macropinacoid is almost always shining, while the basal pinacoid is very often dull, as though finely etched. In color the duller crystals are of a grayish black ; the brighter ones of a pure black. The streak is, when not other- wise designated, a dark brown, and the powder, grayish black. The mineral from the Hills differs from specimens obtained from other sources in two respects: in fracture, which is rather fine-grained and quite dull in luster, while sub-conchoidal frac- ture and iridescence on fractured surfaces are almost wholly wanting. | | 92 W. P. Headden—Columbite and Tantalite. The smaller crystals are more highly modified than the larger ones, as the following readings show. Both crystals here given are from the Etta mine. The forms observed are: 001, 061, 031, 032, 010, 110, 180, 100, 122, 132, 102, 181, 101(?), 111 (?). A fragment of a small and very bright crystal gave the follow- ing: 001, 031, 082, 010, one prism, probably 130, a brachy- pyramid 122(4), 102, 113. The larger crystals are much simpler, the usual forms being 001, 031, 010 and 100. The crystals from the unknown locality have a rather strong luster on all surfaces, and 010 is strongly striated, due to polysynthetic crys- tallization. The macrodomes are wanting, and the other sur- faces are 110, 100, 162(%), 102, 181, 001. The crystals from the Advance claims have a different habit, being prismatic. / The occurrence of columbite in the northern Hills is con- fined, so far as known, to the stream-tin and to the three claims, the Centennial, the Uncle Sam and the Yolo. The crystals from the stream-tin are either tabular or stout prismatic in habit with quadrangular sections. Those from the Centennial claim are bright tabular crystals resembling those from the Etta mine; the few small crystals obtained from the Yolo claim show only the three pinacoids. The mineral is not abundant in this section, neither of those claims having furnished more than a few pounds of it. My specimens from the stream-tin came from Mallory and Upper Bear gulches; for the former I am indebted to Mr. Mark Hydliff, for the latter to Capt. St. John, both of Bear Gulch. The columbite from Mallory Gulch and from the Yolo mine is different from that of the southern Hills, and also from that found on the Centennial claim. The latter occurs in an intimate mixture of albite and quartz, and forms black, shining tabular crystals, while the Yolo mineral occurs in irregular masses In a mixture of albite, quartz and muscovite. Its color is dark gray rather than black, and the small plates of mica adhere to it, forming a kind of coating. These masses and the only tabular crystals which I have definitely recognized, have been broken and the parts moved past one another ; the parts correspond perfectly, and the space between them is filled inditf- ferently with quartz, fine granular albite or mica, according to the nature of the adjacent mass, which shows the order of their separation and the igneous character of the vein. Method of analysis.—The mineral was decomposed by fusion with potassic hydric sulphate, the fused mass powdered and boiled out with water, at least twice, and the mixed acids digested with ammonic sulphide to remove any stannie and tungstic oxides. I found Blomstrand’s objection to fusion with sodic carbonate and sulphur, 1. e., that some of the acids go into solution fully justified. The ferrous sulphide was dissolved W. P. Headden—Oolumbite and Tantalite. 93 out with dilute sulphuric acid, the mixed acids were thor- oughly washed and dissolved in hydrofluoric acid, the solution after the addition of a sufficient quantity—8 to 9-tenths gram— of potassic fluoride, was evaporated on a water bath until the residual mass was simply moist—it was not wet and also not perfectly dry ; for if evaporated to perfect dryness, even at the temperature of a water bath, the subsequent solution in water is apt to be turbid, due to the decomposition of the double fluoride. The moist mass was dissolved in the least possible quantity of boiling water, the solution concentrated a little on the water-bath, and then allowed to cool. The tantalic potassic fluoride will have separated, almost completely, by the time the solution has become cold. After standing for an hour or so the crystals of potassic tantalic fluoride are filtered off and washed with water acidulated with hydrofluoric acid and containing also a little potassic fluoride. The united filtrate and wash-water are again evaporated, when a small amount of the double salt will be obtained. This second crystallization should be examined under the microscope for the plates of: potassic columbic fluoride, the appearance of which is a good indication that the solution has been sufficiently concentrated to allow of the complete separation of the potassic tantalic salt— a third evaporation is seldom necessary. I find this method for the separation of tantalic from columbie acid preferable to that proposed by Rammelsberg, i. e. to fuse with potassic fluoride. The method as described yields clear solutions of small vol- ume. The complete but not over-washing of the potassic tan- talic fluoride is the most delicate manipulation in the process. The filtrate containing the columbic acid is evaporated on a water-bath, after the addition of 25-30 dreps of concentrated sulphuric acid, so long as aqueous vapor is given off, when it is transferred to a sand bath and a part of the excessive sul- phuric acid expelled, the columbic acid is subsequently thrown down by addition of a sufficient quantity of water and boiling. If the quantity of columbic acid present is large, it is better to add less sulphuric acid, about half so much, and a quantity of potassic hydric sulphate, evaporate to dryness and fuse the mass—the columbie acid obtained by boiling the fused-mass with water is more granular and filters better. The tantalic acid was invariably weighed as Ta,O,, after ignition in an atmosphere of ammonic carbonate. The analyses of my specimens presented no other difficulties. The hardness of the specimens varied but little from 6, and the fracture as previously stated is uneven, with a tendency to fine granular rather than to sub-conchoidal. The sp. gr. and composition vary not only with locality but with the individual erystals from the same locality to such an extent that from an 94 W. P. Headden—Columbite and Tantalite. analysis of one crystal, not even an approximate estimate can be made of the composition of an adjacent one. Of the following analyses, I-VIIi, were of specimens from the Etta mine. Some notes about the individual specimens analyzed are here added: I-VIII. Hita Mine.—I. The original large piece of rock, from which this specimen was broken, is now in the cabinet of the University of New York, and this, which is an older analysis, is given here because it is the only specimen having so low a specific gravity which I have found at this locality. The tantalic and columbic acid were separated in this analysis by fusing with caustic soda and subsequently treating the solution with carbon dioxide. IV. This was one of the group of three crystals weighing 304 lbs. V. A large individual crystal weighing 14 lbs., for which I am indebted to Dr. F. R. Carpen- ter. WVlaand 6. These are not duplicate analyses of the same piece, but of what I supposed to be distinct specimens. One analysis was made a year subsequent to the other. VlIla. Crystal weighing about a pound, the smallest of the crystals forming the group, weighing 304 lbs. It seems to be inter- grown with the other crystals at the base. WVII6. Specimen found in the collection of the late Prof. Jansen, a fragment of a large crystal, showing the characteristics of the Etta mineral. VIII. The third crystal in the group of three before mentioned, shows but two pinacoids, 010 and 100. Theupper portion of the crystal is broken off. For analysis of the other crystal see analysis Nos IV and VIIa. IX. Peerless Mine.—Fragments of a crystal from a mass of crystals found on the surface; occurrence similar to that at the Bob Ingersoll Mine. X. Cora Mine.(?)—A large massive piece, free from rock having the appearance of having been broken out of a larger piece. It was obtained from Mrs. Wm. Franklyn. While this specimen is from another locality, and has different physi- cal properties from the preceding it has the same molecular ratio. 7 XI. Peerless Mine.—Part of the second mass found in th mine, analysis No. 1X was of the first piece found. They resemble one another more in composition than in physical properties. XII. Bob Ingersoll Mine.—F¥rom the mass originally de- scribed by Professor W. P. Blake. The fragments show that this was a large aggregate of crystals; one piece showed a crystal with fair terminal surfaces. XIII. Sarah Mine.—From the large mass described on page 90. This and the specimen from the Cora are the W. P. Headden— Columbite and Tantalite. 95 only samples which are not unquestionably crystallized; it may have been a very large crystal; but it is not an agaregate of crystals as was the mass from the Bob Ingersoll. | Se ee veda Wve. wae hvala. VilIO. | VEE | | Sp. grav. 5890 6181 Se ee 6°245| 6°376) 6°515) 6°612 SS ee 6107 6-750 Cb.0; 54°09 47:05) 46°59 40°37) 3994) 35°11 = 35°17) 31°80 ales WP298 1S Ta2Os 18°20) 34:°04| 35°14) 41:14) 42°96) 47-11 47:08) 52°14 52°49) 53-28 SnO2 NOM ORO Oils). ONs) ine 0°35 0°37, 0-10 0:09 0:13 FeO OT eo V4 8228) 8259) 8e37 8°38) 6°00 6:10 6°11 MnO 07| 7 80| 10:94) 9:09) 882) 9°26 9°02; 10°T 110°71) 10°40 CaO Cesk eee ara Ms Lee | POSS} soo PrP ee, ct Ns ete Gi pee 2 pron has 100 88) 100°33)100°29) 99°89 100-31 100-20 100°02|100°75 100°70) 99°78 Atom. equiv. | | Cb.0; Al-8.2)| 35:12) 34°80) 30°12) 29°80) 26-16 ~ 26°25) 23°73 23°37) 22°22 —>—— eS = 8°19! 15°33! 15°83) 18°53) 19°35) 21°62 21°20) 23°48 23°64) 24-00 eas OPA OUsp VOWM apes) OoAw 0:20) 0°06 0:06 0°09 a —_——- — 56°01/ 50°66) 50°76) 48°74) 49°15) 47°88 47°65! 47-27 47-07) 46-31 FeO 15°57| 15:48; 10°30) 11°50) 11°93) 11-62 11°64) 8°33 8:47, 8:48 9:96) 10°96) 15°40) 12°80, 12°33) 13-20 12°70) 15°08 15-08) 14:75 25°53) 26:44) 25°70) 24:30) 24°26) 24°82 94°34) 23-41 23°55 23-23 Atom. ratios. Ch sta 621 ies | we 3) 523) 3: 2 5:4 18 Tl '1:1:08 exe MiSs oe. Wears sk ets I yaa B38 by 4:7 * -10 MgO XIV. Locality unknown.—This crystal was black, shining, vertically striated, tabular in habit, with 010 somewhat curved due apparently, to the successive deposition of thin plate-like individuals, each a little narrower than the preceding one— this cause will also explain the striation in this particular ease. XV. Mallory Gulch.—Nigger Hill District. Material was furnished me by Mr. Mark Hydliff, its color, streak and powder were light-brown; hardness inferior to that of the columbite from the veins; mass much cracked and inclosing mica. Analysis X Vb vives the result after treatment with HCl. XVI. Same source, more compact but otherwise same as preceding. Analyses XIV, XV, XVI, agree in giving the following approximate molecular formula. 38RCb,0,+2RTa,0,, with R=Fe, Mn,. oN 2 These specimens have already undergone some alteration indi- cated by the presence of lime, magnesia and ferric oxide solu- ble in hot dilute hydrochloric acid. The low ratio of the acids to the bases is probably due to this cause. A similar 96 W. P. Headden—Columbite and Tantalite. fact has been observed in regard to the stream tin, i. e. that it is richer in iron than the cassiterite from the adjoining lodes. XVII. Yolo Mine.—Nigger Hill District My attention was called to this occurrence of columbite by Capt. St. John. owner of the property who also furnished me my best speci- mens of the mineral, This is different from any specimen yet described. It is fine-grained, gray-black in color, and the small irregular masses are penetrated by seams of mica and coated with scales of the same. It is the only specimen in which I have detected any admixed cassiterite. From analysis X VIIa, 4:46 per cent, and from 6, 4°64 per cent have been deducted. The high percentage of tantalic acid indicates that this mineral is rather a tantalite than a columbite; on the other hand the few small crystals obtained from this locality have the form and habit of columbite and if this observation is correct, the mineral should be classified as columbite. The three following analyses are introduced here, partly for their own sake and partly for comparison. XVIII. Lurkey Creek, near Morrison, Colorado. Specimen furnished by Mr. Richard Pearce of Denver. It occurred as plates packed close together and enclosed between them was some pinkish feldspar, it is stained with a thin yellow ochreous incrustation. XIX. Haddam, Conn —Specimen bought of Messrs. Geo. C. English & Co., Phila. Color black, luster sub-metallie rather shining, fracture sub-conchoidal with slight iridescence on fracture surfaces. Easily distinguishable from the Black Hills mineral. XX. Mitchell Co., N. C—Specimen bought of Dr. A. E. Foote, Phila., it resembles the Haddam mineral but is not so compact. The first eight specimens are all from the Etta mine and are arranged (p. 95) in the order of their specific gravities. It will be seen that the amount of tantalate increases with the specific gravity and emphasizes the fact that these various isomorphous mixtures not only occur at the same locality but may even form the individual members of groups of crystals. They all have the habit and form of columbite, but the ratio of Cb: Ta grad- ually falls from 6:1 to 1:1, and in the case of the Yolo min- eral becomes 1:14. If we examine the ratios afforded by the two specimens of Broddbo tantalite analyzed by Professor Rammelsberg we find in one case the ratio of Cb: Ta=1:1, in the other 3:2. Professor Dana says of the columbite from Northfield, Mass., analyzed by W. J. Comstock (Appendix III, page 30), “The Northfield mineral had the form and habit of ordinary columbite though it is essentially a tantalite. This was also true of the Branchville (Conn.) mineral... .” The W. P. Headden—Columbite and Tan talite. 97 G Nie Oe es ee sees 7a belie 26°16 26°54) 25°12 me Cl ® Incl. WO; 1°14. 23°90 23°11} 29°10 | 28:12) — 4:5 No | | TCS pile eg XS (Pn, RG TS | XV, ecru) 9) | 6373 | 6393 | 6-445 5901 5804 6-565 Opes ee el) 2k oe 37-29 | 37-91 | 40°28 | oo. 57°32 | 61°72 | 40°07 The O eel anii wearin 44-87 | 44°55 | 42-09 | 23:43 | 18:93 | 42°92 On oe fe hs SNe 0-09 | 0-09 | 019] 0:09 0:09} 0-25 | 0-20 Hie Opts ys Fig Ree Gru) G10) 6 TON 618) 56:29.) Wee) |) 9-73 Oye erin es Fa ena LI-O29) 1205) i238 13:42) 13955 | 867 | 1-24 CIO) DI a I i eines eee ECO 2d ar asa ee etree erccera vc | nape Ey es 100'14 | 100-30 | 100-49 10067 100°68 100-79 100-16 Atom. equiv. | Cin O ei Sh 27-83) |, 28°30 | 30°06) =... 49°80 |-46-07 | 29:90 er Ore ee eee tae Ee 20°21 | 20:07 | 19°00 | __._ 12°80 | 8-53 | 19°34 SnOnmenewer dia Sai) a. Bee Ossie 0:06 yO Msi ets es 0-06))) O:'\ O-1s 48:10 | 48-43 | 49°19 | __.. 55°66.| 54-77 | 49:37 | | | | NSC Pi pets ie en seers 9°54 | 930) 9:30) .... 8:80 | 15-77 | 13°50 Min@eeshis sees eh foo lis Ga NS:85 e214) 192001 11-92) |, 10:20 25°06 24:86 | Doel5y Ieee 212805) 2491-23-70 Atom. ratios | | | | OP SVG Maa Eee Ue eet a 2185 2) 28322) 322 | 2-2 0132 OTE pete & Wer mings ete sae Sd Gy Sy etaile OR) Os il GR ear aa ACI pea ya ae sere Nr XGVOS | MOVIE PR Va VAI ORV LL. | XT We CX. Sp. grav._.--- 6-232 | 6469 67592 5383 | 5-780) ObOes eee) 41°69 40°48) 37-28 24:40 25:01! 73:45 | 60°52) 170-98 TO ea 40°19 40°97] 44-48) 57°60 56°82) 2-74 | 19-71] 9-27 BuO iene bs OI 20-15) 0-6) 041 Ora 1352 10-09 0-17 Be Oper ters iiss 9°88 9:95) 9:29) 1446 14:03) 11°32 | 12°64) 12-21 Mai Oe ees 870 9:03] 8°68) 2°55 2°58, 9-70 151) E30 CaO eee 2. renege | 0°73 0°79 0-61 tr. 0°80 100°67 100°58 99°8910015 99°54 100:47) 100-73 Atom. equiv. | | | | | ChsOpe sh Poke 31-11 30°20) 27-82) 18:34 =—-18'88, 55°00 | 45°16] 52:97 nan O gas See. 18-10 18°46] 20°00) 25°95 25°60) 0°30 | 8:88) 4:17 SHOg ost yt 0°06 0710 010 0-31 0°20 0-64» 0°06 O11 49-27 48-76] 47:92) 44-60 44°68 55°94 | 54°10 57°25 He @ ger iers2.. 13-72 13°82| 12°90| 20°30 19:46) 15-70 | 17-55} 16-96 MinOmens 12-44" 12-72)'-12°22) 3-60 3°65) 13-40 | 10°57] 10-30 —-- ——-——+ -—— (a0 1°35 > Tnel. WO; 0°50. 98 W. P. Headden— Oolumbite and Tantalite. analysis of the Northfield mineral gives 1:14 as the ratio of Cb: Ta, while that of the Branchville mineral by the same analyst gives 1:1 for the ratio. It will be noticed that of the twenty specimens from different localities in the Black Hills, seven of them contain the Cb and Ta in the ratio of 3:2, four contain them in the ratio of 1:1 and one contains them in the ratio of 1:14. There is no doubt as to the form of these specimens unless it be in regard to the last, but in the case of the Northfield mineral, which gives the same ratio, i. e. 1: i4, Professor Dana expresses no doubt. The tantalite from Yan- cey Co., N. C., analyzed by Comstock (Appendix III, p. 118), gives the formula 6RTa,O,+4RCb,O,, while the columbite from Northfield, Mass, and the Yolo Mine, Lawrence Co., S. D., give the formula 5RTa,O,+4RCb,O,. If the Broddbo and Yancey Co., N. C., specimens are real tantalites and the North- field and Yolo minerals real columbites, there is an overlap- ping of specific gravity and chemical composition which destroys their value as guides in determining these minerals when the columbite and tantalite molecules are nearly equal in number. It was my intention to carry my work further and endeavor to show that there is chemically no sharp line between them, but that the tantalate may predominate in a true columbite to even a greater extent than is indicated by any of the analyses. In form the columbite is not always tabular or square prismatic in habit; the pinacoids to which these habits are due are sometimes very subordinate and the columbite becomes as pronouncedly prismatic as tantalite. I have so far been unable to determine the superior limit of tantalic acid compatible with the columbite form. The Turkey Creek (Colorado) mineral, deserves mention as being an almost typical columbite, but is, like the greater number of the Dakota columbites, rich in manganese. It is also rather remarkable that it is the only one which contains tungstie acid. A pure ferriferous columbite has not yet been found in the Black Hills, the only specimen approaching it is that from the Yolo Mine which contains the Fe and Mn in the ratio of 5:1; by far the greater number of all the others are rather mangan- iferous than ferriferous columbites, this is in marked contrast to the tantalites, analyses of which are given later. 9, TANTALITE. _ Professor *Schaeffer published in the Transactions of the American Institute of Mining Engineers, vol. viii, page 233, the identification of a mineral from the Etta Mine as tantalite and gives the following analysis: Ta,O, 79°01, SnO, 0°39, FeO 8:33, MnO 12:13=99-°86, sp. gr. 7°72. I have good reasons for believing that Professor Schaeffer’s material was from the W. P. Headden—Columbite and Tantalite. 99 Etta Mine, but I have not been fortunate enough to find any tantalite at this locality, and Professor Schaeffer’s analysis does not justify his identification. Professor Schaeffer states that he was unable to find the least trace of columbic acid, and conse- quently only the tantalic acid appears in the analysis. If we -ealeulate the atomic equivalents on this basis we obtain the following values : Ta 35°60, Sn 0°26=35°'86 and Fe 11°57, Mn 17°09=28°66 The ratio is then 35°86: 28:66=14:1 instead of 2:1. If we calculate the oxygen ratio on the same basis we obtain 3:1: 1 instead of 5:1; whereas, if we consider that the 79:01 per cent is all columbic acid and calculate the atomic ratios, we obtain for Cb: Fe+Mn, 2°06: 1 and the oxygen ratio becomes 5:1: 1; which are very close approximations to the true ratios for columbite. A comparison of Professor Schaeffer’s analysis with analyses XIla@ and 6 makes it evident that his specimen was essentially the same mineral. The assumption that there is no tantalic acid in an Etta columbite is contrary to the results of my tests and analyses, still, it is only on this assumption that the analysis gives a cor- rect ratio showing the mineral to be a columbite, but a very exceptional one for the locality. In the summer of 1886 or 1887, Mr. Frank Hebert of Grizzly Bear Gulch brought some stream tin to the Dakota School of Mines to have it smelted and the tin run into bars. The yield was exceedingly unsatisfactory and a portion of it was not smelted, but by accident or otherwise was mixed with some stream tin from Bear Gulch, a locality in the Northern Hills. A little over a year ago I examined some of this material and was lead to believe that some of it was tantalite, and the preced- ing facts not being fully known to meat the time I supposed the tantalite to be from the northern section of the Hills. This was not the case; as I have since found more of it in stream tin from Grizzly Bear Gulch but have found none in the stream tin from Bear Gulch. The stream tin in which I found the tantalite was also from Mr. Hebert’s placer ground near the Tin Queen Mine. The largest piece weighs 5 grams and has a specific gravity of 8-2. ‘The mineral has not yet been found in place but these fragments have unquestionably been derived from the Tin Queen lode which lies immediately above the placer ground—this placer is worked for gold. ‘The tantalite is perceptibly harder than the columbite and the streak and powder are dark brown. The method of analysis was the same as for columbite. Am. JOUR, SCI.— THIRD SERIES, Vou. XLI, No. 242.— FEBRUARY, 1891. 7 100 W. P. Headden—Columbite and Tantalite. I. Hebert’s Placer, Grizzly Bear Gulch, Pennington Co., S. D. Piece weighed 2 grams. II. Same locality, fragment not so large as preceding. III. Same locality, weight of sam- ple 2 grams. IV. Coosa Co., Ala., specimen bought of Messrs. Ward & Howell, Rochester. Weight 3 grams; color black, streak brown. The surface was quite regularly and deeply pitted. TANTALITE. if ib Dik AV Sp. Grav. Meads 7°789 8-200 aes Fak Ore ss Site 78°20 78°35 82:23 Est ChsOzee Bae pS 6°23 6°24 3°57 8°78 SHOR ond tte 0°68 0:58 0°32 5°38 BeOS. fer ase se ee 14°00 14°05 12°67 8°44 Mai Oi eo gae 0°81 114 133 Desh 99°92 100°36 100°12 99°34 Ign. 0°20 deducted. Atom. Equiv TAO peaibae Hee aes 35°29 37°05 32°15 Ch5O; ee Bore ON 4°65 4°66 2°66 6°55 Snip an eee oe 0°45 0°38 (22M 3°58 40°33 40°33 39°92 42°28 die) 0 Ake ak Spake Sa 19°44 19°48 MES 171 MnO 2 aeee ono & 1°14 1°60 15S 7:56 20°58 21°08 19°38 19°27 Atom. Ratio at AO ys tae ears Bisa 8:1 14:1 bee I have found several fragments of crystals showing surfaces, and one crystal was sufficiently well preserved to enable me to recognize the habit of the mineral and the following surfaces : 001, strongly etched, two pyramidal surfaces very poorly developed and one prism; the sp. gr. of this crystal is 7°212. These analyses, especially III, show that these tantalites are poor in columbic acid and manganese. It is remarkable that this should be so, as the columbites of our localities are charac- terized by a large and often predominating portion of the latter. I have also found two small specimens of tantalite in the stream tin from Mitchell’s Bar, a locality about one and a half miles north by east from the Etta Mine, but no analyses have yet been made of them. 3. MANGANESE COLUMBITE. The mineral described in this note occurs on the Advance Claim, one of the Dixie group of tin mines, on Elk Creek about one and a half miles south of the Etta mine, Penning- ton Co., 8. D. It occurs in a vein of granite which apparently folds over the crest of the hill; its thickness was not measured W. P. Headden—Columbite and Tantalite. 101 but did not exceed two feet. The columbite was found at only one point: the underside of the granite is here very even and smooth and consists, for about two inches, wholly of mica erystals whose cleavage planes stand at right-angles to the wall. The inner edge of this band of mica is also sharply defined but irregular. The outer surface, that is the under surface as the granite lies, is filled with minute crystals of columbite lying in all directions as though a crop of small crystals had separated first, forming a swarm of them which adhered to the wall and the larger crystals seem to be extensions of these points into-the mass ; only a few points, however, have developed into larger crystals. If there were two periods of growth, this would account for the peculiar pointed appendages to many of the crystals. Many of these crystals are short, doubly ter- minated but much distorted, and attached at the side as the more perfect ones indicate. The band of mica varies in thickness up to two inches and seldom incloses any other mineral than the columbite; the quartz and feldspar, (mono- and triclinic) rest upon the mica while an occasional beryl penetrates its mass. The columbite crystals do not enter the beryl as they do in the Etta mine, but are sometimes found in the feldspar, immediately adjacent to the mica, they are often rusty, and some of them thickly coated with oxide of iron, and the most of them are not at all or only faintly striated. The erystals have a habit often observed in ordinary colum- bite, and such approximate angles as can be obtained corre- spond with those usually accepted. The planes present are: 100, 001, 010, 110, 580, 183, 021. The development of the prisms 530, 110, especially the former, gives the crystals a flat- tened form in the direction of the macrodiagonal axis. I. One of the largest crystals, weighing one and a half grams, was used for this analysis; the crystal was rusty, and had to be cleaned by boiling in dilute hydrochloric acid, its color after cleaning was black, luster sub-metallic, a little shining, fracture uneven, streak brown, powder grayish brown. Specific gravity = 6170. Il. Three small crystals, specific gravity not deter- mined. The analyses are as follows: It, Il. Sp. grav. = 6°170. Sp. grav. undetermined. At. equiv. At. ratio. At. equiv. At. ratio. Cb,0; ---. 47°22 35°25 45°66 34:07 ) Ta,O; ---- 34°27 15°44 + 50°90 2°07 35°53 ~—s«16°00 } 50°32 2°01 Sn0,____- 39 21 38 25 J Maou. 1°89 FG Qe 2-29 3040) oe MnO ____- 1625. 21°97 t 24 ay: eon aay y uote 99°98 100°00 | Ration Chis La = 123) Hec-Mint=°2)+ 1. 102 WV. H. Darton—Geology of Florida phospiate deposits. | The results of I and II agree as closely as could be expected when we consider that each of the three different crystals of II may have, and probably did, represent different molecular mixtures. Art. XII.—Wotes on the Geology of the Florida Phosphate Deposits; by N. H. Darton. Durine the past year the phosphate deposits of Florida have become of considerable commercial importanee and _at- tracted widespread interest. As practically nothing was on record as to their geologic relations the writer has devoted sevy- eral weeks to a preliminary study of the principal deposits and this paper 1s a summary of the results. The phosphate regions of Florida occur mainly in the west- ern and west-central portions of the peninsula, comprising a series of irregular areas scattered at varying intervals along a narrow belt extending from near Tallahassee towards Gaines- ville and thence nearly to Charlotte Harbor, a distance of 250 miles. The entire region is not yet fully explored but the vast extent and commercial importance of the deposits are satis- factorily established and it is safe to predict that Florida will finally become a prominent source of phosphate. The deposits are exceedingly irregular in extent and richness, and while there are many areas underlain by large bodies of high grade mineral, the great number of the deposits consist of impure, thin or scattered beds of no economic value. The phosphates are readily separable into three classes: 1. Rock phosphate, a homogeneous, more or less completely lithified, light colored phosphate of lime, constituting the sur- face of the middle Tertiary limestone formation. 2. Con- glomerate, consisting of pebbles of phosphate rock imbedded more or less thickly in a matrix of phosphate sand, marl and arenaceous and argillaceous materials. This fragmental forma- tion lies in great sheets on the surface of the limestone, in some cases overlapping the edge of the rock phosphates, from which its pebbles were derived. 3. Liver drift, consisting of phosphate pebbles derived both from the rock phosphate and the conglomerate and constituting great placer deposits in the stream beds draining the other phosphate regions. So far as is known the occurrence of the rock phosphate is restricted to a narrow irregular belt extending through eastern Citrus county, northward through western Marion, probably to the exposures near Albion, and thence with more or less contin- uity through Trenton in Alachua, Steinhatchee in Lafayette NV. H, Darton— Geology of Florida phosphate deposits. 103 and Lauraville in Sewanee, possibly to Monticello, in Jefferson, Perry in Taylor, and some other reported localities in the same direction. This region is not by any means underlain by a continuous sheet of phosphate but includes irregular masses of variable sizes and thickness scattered about in detached bodies often widely separated by barren limestone areas. At Dunellon in western Marion county there are representa- tive exposures In the extensive mine openings that are now being worked. Here the phosphate was found outcropping at a number of points in the woods and in low bluffs and reefs in the Withlacoochee river near by. The deposit appears to constitute a large basin of which the bottom was not reached in a thirty-foot pit in the center. The phosphate is in large part a mixture of chalky and flinty rock similar in texture and structure to spongy limonite, but usually creamy white, gray or bluish gray in color. Some portions consist of dense homo- geneous lithified materials, others are spongy, stalactitic or laminated. A fair average sample of high grade mineral was found to contain 83 per cent of phosphate of lime and 44 per cent of carbonate of lime. The Conglomerate phosphates occupy a very considerable area in Florida, and although not as rich in phosphate of lime as the phosphate rock they will be of commercial import- ance. The principal deposits now known are south of the southern termination of the rock phosphate belt, in the west- ern part of Polk county in the vicinities of Bartow and Fort Meade, where they constitute sheets of wide area overlying the limestone, sometimes to a thickness of from twenty to thirty feet. These conglomerate phosphates consist of small pebbles of 80 to 85 per cent phosphate rock, usually light colored, im- bedded in a soft chalky matrix of phosphate sand, carbonate of lime, clay and sand in variable proportions. High grade con- ae will average from 73 to 78 per cent of phosphate of ime. At intervals along the eastern border of the rock phosphate region and overlapping it at some points there are fragmental and conglomerate deposits of considerable extent but they are much more diverse in composition than the great sheets in Polk county. At the Dunellon mine, northern opening, there is a deposit of this class and the porous, pebbly sandrock— “Chimney rock” of the Gainesville region appears to belong to the same formation. The Liver drift deposits of phosphates are of great eco- nomic importance, for they are rich in phosphate and can be mined at small expense. Nearly every little water course in the phosphate regions contains accumulations of phosphate 104 WV. H. Darton— Geology of Florida phosphate deposits. pebbles and along the larger streams there are many thick and extensive pebble deposits. Peace Creek drains the Bartow- Fort Meade conglomerate region and flows over many great placer deposits, some of which are now extensively worked in De Soto county. The Withlacoochee, near Dunellon, and Alifia Creek northeast of Bartow also contain extensive accum- ulations of pebbles. These deposits consist of rock-phosphate pebbles usually from an inch to one-quarter inch in diameter, mixed with more or less sand and usually with bone fr agments and occasional flint pebbles from the limestones. Age and geologic history.—The three geologic formations to which the phosphates belong are distinctly separate stratigraph- ically, and represent a long interval of geologic time. The rock phosphates appear to be the deeply eroded remnants of the phosphatized surface of the middle Tertiary limestone; the conglomerate deposits overlie these limestones unconform- ably and in the Gainesville region at least, appear to be Mio- cene in age, and the river drift deposits are apparently en- tirely subsequent to the great mantle of Pleistocene white and gray sands which covers the entire peninsula to a greater or less depth. Excepting in its light color the rock phosphate is a physi- cal counterpart of the brown limonite iron ores of the Appala- chian limestone valleys and the deposits have very similar structural relations. I have found at a number of localities that the massive phosphate graduates into the limestone usually by short transitions and many areas were discovered in the phosphate belt and under the conglomerate in the Bar- tow region where the limestone is only partially phosphatized. In the mines at Dunellon the massive phosphate is apparently continuous with the limestones, but unfortunately at the time of my visit there were no continuous exposures from rich phosphate to the walls of the basin, and the bottom was not yet reached, so I was unable to establish a graduating sequence at that locality. There are, however, in the massive phosphate, occasional casts and impressions of the same middle Tertiary mollusca undoubtedly lying as they were originally deposited. The origin of the phosphate of lime is not definitely known, but it seems exceedingly probable that guano was the original source and the genesis of the deposits similar to that of the phosphates on some of the West Indies. Two processes of de- position have taken place, one the more or less complete re- placement of the carbonate of lime by phosphate of lime, and the other a general stalactitic coating on the massive phosphates, its cavities, ete. NV. A. Darton—fecord of deep Well at Lake Worth. 105 The apparent restriction of the rock-phosphate deposits to the western “ridge” of Florida may have some special bearing on their genesis but at present no definite relationship is per- ceived. The aggregate amount of phosphate rock distributed in fragmentary condition in the various subsequent formations is very great, greater by far than the amount remaining in its original position and it is possible that the area at one time in- cluded the greater part, if not all, of the higher portions of the peninsula. As this region apparently constituted a long, narrow peninsula or archipelago, during early Miocene times, it is a reasonable tentative hypothesis that during this period guanos were deposited from which were derived the material for the phosphatization of the limestone, either at the same time or soon after. The pebbles of the conglomerate phosphate were undoubt- edly derived from the rock phosphates, for they are identical in appearance and composition and overlap them as a shore deposit. Evidence in regard to the age of the conglomerate formation is very meager. The only organic remains I met with were two imperfect casts of Pectens in the “ Chimney rock”? near Gainesville. These had a Miocene aspect but the evidence is not by any means conclusive. This ‘“‘ Chimney rock ” of Gainesville is a porous sandstone containing a small proportion of pebbles of phosphate rock, lying unconformably above the Vicksburg limestone. It is the structural equivalent of the conglomerate beds of the Polk county region but they may prove not to be identical in age. The phosphate deposits of Florida will require careful de- tailed geologic exploration before their relations and history will be fully understood, and it is the purpose of these prelim- inary notes only to throw some light on their more general features. Arr. XIII.—Record of a deep Well at Lake Worth, southern Florida ; by N. H. Darron. In June, 1890, a well was completed at Lake Worth, on the southeastern coast of Florida, which penetrated the great sand mantle and extended down into the Vicksburg limestone to a depth of 1212 feet. It was bored by Mr. J. A. Durst, who has very kindly placed the borings at my disposal. Unfortunately, no samples were collected for the first 400 feet, and there are several other gaps for which information is lacking. Notwithstanding its imperfections the section is an 106 S. L. Penfield—Chemical Composition of Aurichalcite. exceedingly important one, for it throws some light on the general stratigraphy of a portion of Florida of which little was hitherto known. ‘The well record is as follows: 0O— 400 feet. “Sands with thin layers of semi-vitrified sand at 50 and 60 feet.” 400— 800 feet. Very fine grained soft, greenish gray quartz sand, containing occasional foraminifera and water-worn shell fragments. 800— 850 feet. No sample. 850— 860 feet. White sands with abundant foraminifera of four or five species. 860— 904 feet. No sample. 904— 915 feet. Gray sands containing sharks’ teeth, small water-worn shell and bone fragments, sea urchin spines and lithified sand fragments. 915-1000 feet. No sample. 1000-1212 feet. Samples at frequent intervals. Vicksburg lime- stone containing Orbitoides in abundance throughout, together with occasional inde- terminable fragments of molluscan casts, corals and echinoderms. It isacreamy white, hard homogeneous limestone throughout. There was also sent a box containing two species of Dentalium and a Turritella, all of Miocene facies, but, unfortunately, no data could be furnished in regard to the depth at which they were found. The ages of the series overlying the limestones could not be determined definitely from the material received, but the organic remains from 800-915 feet suggest Miocene, especially if the unlabeled sample belongs here, which is probable. The 400-800 feet beds contain several of the same foraminifera that are found at 850-860 feet, and probably are part of the same formation. Art. XIV.—On the Chemical Composition of Aurichalcite ; by 8. L. PENFIELD. THE. material for the analysis in this paper was received by Professor E. 8. Dana some years ago from an unknown local- ity in Utah. Very good specimens of aurichaleite occur at both the Kesler Mine, Big Cottonwood and Cave Mine, Beaver Co., Utah, and the specimen under investigation very closely resembles one from the Kesler Mine in the cabinet of Professor Geo. J. Brush. As some question still exists regarding the S. L. Penfield—Chemical Composition of Aurichaterte. 107 formula of aurichalcite and as the mineral appeared to be of unusual purity the following investigation was undertaken to determine if possible its true chemical composition. As far as can be told from the small hand specimens in the author’s possession, the mineral occurs in narrow seams about one centimeter wide in an impure limonite ; calcite was asso- ciated with it, especially on one side of the seam and great care was taken to pick out pure material. The aurichalcite had the usual pale bluish-green color and occurred in radiated tufts of microscopic crystals so soft and loosely aggregated that a cluster of them could readily be pressed to a powder between the fingers. No definite idea regarding its crystalli- zation was obtained by examining under the microscope. It was seen that it occurred in little flattened prismatic crystals with mostly broken, irregular contours in general agreeing with the description given by A. Belar.* After ascertaining that the mineral did not lose water by heating at 100° C. the larger selected fragments were boiled in water to expel the air from between the crystals and the specific gravity taken very carefully on a chemical balance ; the two portions were then analyzed separately with the fol- lowing results. No. I. | No. Il. Weight of mineral-__---- 05690 0°3342 Specific gravity ..- 4... 3°52 3°63 NOK tn stilt et aes 16°50 16°22 (ORO) fas ae ee aR Oe ena 20°88 19°87 ZNO REELED ewe era met ae ns 52°18 54:01 H.O CNS ere Wb DE Sy 9°91 CaCO; 9°93 CaCO; Ca yerrae sn ae 2 eee a 286 ==) 103 36 = 0°64 100°33 100°39 The finely powdered mineral, weighed in a platinum boat, was ignited in a combustion tube and the CO, and H,O col- lected and weighed in the ordinary absorption apparatus. The copper was separated from the zinc by two precipitations from strong hydrochloric acid solutions with hydrogen sulphide. The larger percentage of CuO in the first analysis is not owing to an incomplete separation of copper from the zinc, as proved by dissolving the copper, after having weighed it, precipitating it a third time and finding no trace of zinc in the filtrate. The variation of CuO and ZnO in the two analyses indicates the mutual replacement and isomorphism of the two oxides. The CaO comes undoubtedly from an admixture of calcite. Correcting the specific gravity and the percentages for 1°53 * Zeitschr. Kryst., xvii, p. 113. 108 S. L. Penfield—Chemical Composition of Aurichaleite. and 0°64 per cent. of calcite respectively in the two analyses, we have the following with the molecular ratios. Theory for I. Ratio. Il. Ratio. 2RCOs, 3R(OH)s Sp.Gr., . 3°54 3°64 where Cu:Zn=2:5 CO, -.-. 16°07 “365 198 16-04 °365 1-98 1614 CuO... 21-21-2672. al 20°00. 259,96 <0 20-79 TnO..).. 5299 Bb oo eG eee seer 53°17 H,0_-.. 10°06 559 3-04 9:99 °555 3-02 9:90 100°33 100°39 100-00 The ratios in the two analyses are almost exactly 2: 5:3 and the formula is therefore 2RCO,, 3R(OH), in which R= Zn and Cu. There seems to be no exact relation between the CuO and the other constituents. In analysis I the CuO:ZnO= about 2:5 and using this proportion in the above formula the theoretical composition given above was calculated, which agrees very well with the first analysis. The strongest proof of the correctness of the above formula is found in the purity of the analyzed mineral and the exact- ness of the ratio between CO,, RO and H,O, both of these are as satisfactory as one could desire in mineral analysis, especially for a mineral occurring in minute tufted crystals in a narrow seam with calcite. Moreover the above formula is the same as that proposed by T. Bottger* in the original description of aurichalcite from Loktewsk in the Altai. His analysis was made in Rose’s laboratory with great care and evidently on very pure material. Other analyses have shown a deviation from the above formula which may have resulted from impurities in the analyzed material or errors of analysis. Thus Delesset+ has described as buratite specimens from Loktewsk in the Altai and from Chessy, France, containing as high as 8°62 per cent of CaO, but as A. Belart and others have proved that CaO is not anormal constituent of aurichalcite, it is quite safe to assume that the material which he analyzed contained calcite; in fact if CaCO, equivalent to the CaO be deducted from his analyses the remainder corresponds closely to the above formula. Other analyses cannot be used in discussing the formula because CO, and H,O have not been separately determined ; they are given together simply as loss on ignition. A. Belar in a recent contribution on this subject, already noticed, gives four analyses of material carefully selected under the microscope so as to avoid all possible impurities. The analyses are as follows: * Pogg. Ann., xlviii, p. 495, 1839. + Ann. Ch. Phys., xviii, 478, 1846. t Loe. cit. S. L. Penfield—Chemical Composition of Aurichaleite. 109 I. Moravicza in Banat. TT. ac ‘é III. Campiglia, Italy. IV. Sardinia. V. Theory according to Belar for CuCOs, 3Zn(OH)ps. . VI. Theory according to the original formula 2RCO;3, 3R(OH)2, Cu: Zn = 2:5, if Jim jue IV. AVE VI. Loss on ignition... 24°91 26°78 26°50 22:97 23°30 26°04 15510) fale tpanees egies: Seem 13°53 . 12°84 9°90 (DLC ey se RR ean eae [11-38] 10°46 16°14 SUG ee a a 20°39 2143 € 20°20 15°58 18°91 20°79 AAO) Sah i ae ae oe 54°70 53°57 55°51 58°72 57°79 5 asd by 100-00 101-78 10221 97°27 100°00 100-00 Water was determined directly only in the first of these analyses, and CO, by deducting H,O from the loss on ignition, or indirectly by deducting the sum of all the other constituents from 100 per cent. From this analysis Belar derives the formula CuCO,, 8Zn(OH), requiring a ratio of CO,: RO: H,O = 1:4:3 while his analysis yields 1:11: 4:00: 3-24, an agreement which is not satisfactory as may also be seen by comparing the theoretical composition V with analysis I. The other analyses are of little value as they do not add up very close to 100 per cent and in II and III the loss on ignition is certainly nearer to the theory for the original formula, VI above, than for Belar’s V. It is possible that Belar’s analysis I is correct and that there is a mineral resembling aurichalcite with a definite formula, but if so it must be settled by more exact analyses and be designated as a distinct species. An analysis by Berzelius* of an artificial salt, prepared by precipitation from a solution of zine sulphate with sodium car- bonate in the cold, washing the precipitate and drying to con- stant weight in a vacuum, is of interest here as he derived for it a formula exactly analogous to that of aurichalcite, 2ZnCO, 3Zn(OH),. His analysis, together with the theoretical compo- sition are given below. CO. H.9 ZnO Berzelius, found___ 15°939 10°714 73°347 = 100:000 Calculated _...__- 16°06 9°85 74:09 = 100°00 In closing the author desires to express his thanks to Prof. E. S. Dana for his kindness in furnishing the material for carrying on this investigation. Mineralogical Laboratory, Sheffield Scientific School, New Haven, Nov. 22d, 1890. * Berzelius, Jahresbericht, xv, p. 180, 1836. 110 C. Barus—Compressibility of Hot Water and Arr. XV.— The Compressibility of Hot Water and its Solvent Action on Glass ;* by Cart Barus. 1. BETWEEN 0° and about 63°, the compressibility of water continually decreases. After this, if temperature rises further, the compressibility increases. It was my original purpose to supplement these results by determining the compressibility of water between 100° and 300°; but I did not get further than 185°, for the reason that at this temperature (and obviously much below it) liquid water attacks glass so rapidly as to make the measurements in glass tubes worthless. 2. The peculiar behavior, in question, has interested many physicists. Grassi” was the first to find that the compressibility (2) of water decreases with temperature, being 50/10° at 0° and 44/10° at 538°. He also observed that the compressibility of solutions is less than that of water. Amaury and Descamps” substantiate the latter result; but they only observe at a single temperature 15°, at which S=45/140°. In Cailletet’s’ experi- ments carried as far as 700 atm., only a single temperature is given, and the same is true of Buchanan’s’ results. After this the subject was vigorously attacked by Tait’ and his pupils, at first particularly with reference to the depression of the tem- perature of maximum density of water, under pressure. .The probability of such an occurrence had been inferred by Puschl and by van der Waals’. Cf. Grimaldi,1.c. In later experiments Tait® studies the thermal relations of the compressibility of water, but only for small ranges of temperature. Further re- sults are due to Pagliani and Palazzo* working with mixtures of water and alcohol, but more directly to Pagliani and Vicen- tini.”” These observers corroborate Grassi’s work, and find that water shows minimum compressibility at 63°. Grimaldi™ critically reviews the maximum density experiments of Puschl, of van derWaals, of Marshall Smith and Omond, and of Tait. 1 This paper will be recognized as part of the work suggested by Mr. Clarence King. 2 Grassi: Ann. de ch. et de phys., (3), xxxi, p. 437, 1851; cf. Wertheim: ibid. (3) xxi, p. 434, 1848. 3 Amaury and Descamps: C. R., lxvili, p. 1564, 1869. 4 Cailletet: C. R., Ixxv, p. 17, 1872. 5 Buchanan: Nature, xvii, p. 439, 1878. Tait: Proc. Roy. Soc. Ed., xi, p. 204, 1881; Marshall, Smith and Omond: ibid., xi, pp. 626. 809, 1882; Tait: ibid. p. 813; ibid., xii, 1882-83, p. 226; ibid., xili, p. 2, 1884-85. 7 Vander Waals: Beiblatter, I, p. 511, 1877. 8 Tait: Proc. Roy. Soc. Ed, xii, p. 45, 1882-83; ibid., p. 223; ibid., 1883-84 Paode . 9 Pagliani and Palazzo: Beiblatter, vill, p. 795, 1884. 10 Pagliani and Vicentini: Beiblatter, viii, pp. 270, 794, 1884; Journ. de phys., (2) xxx, p. 461, 1883. 11 Grimaldi: Beiblatter, x, p. 338, 1886. its Solvent Action on Glass. ala ial Amagat* applying a new method of pressure measurement “a iston libres,” operates with hydrostatic pressures as remarkably high as 3000 atm., and at temperatures between 0° and 50°. He shows among other results relating as yet chiefly to thermal expansion, that the compressional peculiarities of the behavior of water vanish at high pressures and increasing temperatures (interval 0° to 50°), thus further corroborating Grassi. Many data are given; but the research is unfinished. Taitt in a final paper summarizes much of his work and begins a series of experiments showing that the effect of solution is analogous to an increase of internal pressure. A critical revision of earlier work on compressibility may be found in Tait’s “ Prop- erties of Matter.” From this brief summary it appears that results anticipating the contents of the present paper are not in hand. There is another class of experiments relating to the expansion of water in glass tubes to which I must advert. Waterstont published a very full series of results carrying the work as far as 300°. He was annoyed by the action of water on glass, but does not further consider it. For very high temperatures the experi- ments of Daubrée§ and others, are well known. 3. In the present work pressures were applied by aid of Cailletet’s large force pump. The thread of water is enclosed in a capillary tube, between. two end threads of mercury, and the distance apart of the two inner menisci, corres- ponding to any given temperature and pressure, measured by Grunow’s eathetometer. The tube, suitably closed above, is exposed in a vapor bath (boiling tube). At 185° (aniline), the thread of water soon loses its transparency, becoming white and cloudy. fortunately the siliceous water is translucent. By placing a very bright screen behind it, the demarcation between water and mercury remains sufficiently sharp for measurement. After the action has continued for some time, say an hour, the coiumm is solid at high pressures (800 atm.), though it is probably only partially so at 20 atm. In conse- quence of this, threads of mercury break off during advance and retrogression of the column. Further measurement is therefore not feasible. Toward the close of the experiment, moreover, the mercury thread is pushed forward, enclosed by walls of semi-solid siliceous water. The thread is therefore of smaller diameter and the measurement correspondingly inaccurate. In obtaining these data, I followed a customary routine of increasing pressure from zero to the maximum, then decreasing Was coset C. R., cili, p. 429, 1886; ibid., civ, p. 1159, 1887; ibid., ev, p. 1120, + Tait: Challenger Reports, ii, part 4, 1888. { Waterston: Phil. Mag., (4) xxvi, p. 116, 1863. § Daubrée: Et. synthét. d. Géol. expér., 1879, p. 154 et seq., Paris, Dunod. 'g § UL UOAIS SI 4areYO SIqy Jo uoyYvULldxe uy 112 C. Barus—Compressibility of Hot Water and it from the maximum to zero, and taking the mean volume changes corresponding to a given pressure. When the water does not attack the glass, the fiducial mark (pressure low) at the beginning of the series, is regained at the end. When water attacks glass there is much shifting. The, glass was common lead glass and distilled water was used. 4. My introductory work between 0° and 100° contains a mere corrob- oration of some of the results given in §2. As it is not exceptionally accurate I will omit it here. 5. In table 1, the symbols used have the following meaning: Z is the observed length of the thread of water, 6 its temperature, and ¢ the mean time of observation. v/ V is the volume decrement due to the pressure p. Finally @ is the mean compressibility;* i.e. B=(1/p)(v/V). The first series of data were ob- tained at 28°, the next seven series at 185°. Unfortunately I did not observe the time when ebullition ¢ commenced, and some subsequent dates are also lacking. After clos- E |, ing the experiments, I noticed that Rs 7 a fine filament of the upper thread 1 HV +, of mercury, had run down into the 4 ‘7 core of the solid silicate below it. aa /\ _ Possibly this means that there had BY | / ve been progressive erosion due to i V he Y, ~ [= water intruding between the mer- 4 Wh cury and the glass. In this respect = AVY, Lhe the observations are uncertain. § 7. i Vy GAZ 6. To discuss these results I first | y) U Zi « plotted v/ V as a function of p, thus ~ j, Yio of” obtaining a series of curves of some- what irregular contour, the charac- ter of which, however, is obvious. This will be more accurately ob- ie = served by plotting @ as a function T.4 of the length Z of the column, since the time data are incomplete. The a he result is striking. It shows a mean *It would be useless to calculate G by more elaborate means. The correction referred to at the end of this paragraph is such, that if applied, it would accentu- ate the inferences of the text. Its small value appears in §7. ASS Xs he its Solvent Action on Glass. 1018} TABLE ].—COMPRESSIBILITY OF WATER. —__+— Le OG . = x 108, l>Bexehoe JOO D. = x 108, GO < 108 Atm. Aim. | We 20 0:0 ett nie 20 0:0 ane 18:44 | 100 35a | 44 19:57 | 100 93 116 200 OrAbree | 52 |! 200 20°6 114 300 13°40 48 300 32°7 117 400 ea a 49 | 400 42°8 113 185° 20 0:0 apa 185° 20 | 0:0 Bats 20°45" | 100 Come 84 18°92 | 100 nice 146 200 aes = | 80 11°05") 200 25 9 144 300 21:1 75 300 | 39-77 142 400 29°3 17 400 55:5 146 185° 20 0-0 aR aN 185° 20 0-0 ere 20:10 | 100 S800 18:-42¢ | 100 EN gia 200 A ialy es | 951) |) HOO /5 -200 30:1 167 300 27:4 OS | | 300 | 44:6 159 400 34-7 91] 400 60-2 158 185° 20 0:0. ie: 185° 20 0:0 Be 19°94em | 100 See TOD 17°78e" | 100 15:0 188 200 18°3 102 114-20™) 200 31°7 176 300 27:9 100 300 56-2 201 400 38°3 101 | 400 71:8 189 increment of 8, of about 50/10° per centimeter of decrement of length of column. Toward the end of the experiment, the values of 8 increase much faster; but here they are uncertain because of solidification. The total observed decrement of Z is therefore (20:1—17°8)/20:1, or more than 11 per cent. Since the column at the moment when ebullition started must have been longer, it follows that the volume of the system of pure water and solid glass, shrinks more than 11 per cent, in virtue of the solution of glass in water, up to the point of solidification at 185°. By plotting length Z as a function of time, the data though incomplete show that volume contrac- tion of the kind given took place at the rate of 8 per cent per minute. The column therefore at 185° is soon shorter than the original column at 28°. This is an enormously rapid rate ; for were it possible for such action to be indefinitely prolonged, the column would be quite swallowed up in five hours. Hence it appears improbable that the action of water on glass will be unaccompanied by heat phenomena. Of course the rate of solution must increase, as the diameter of the capillary tube decreases. 7. From the importance of these results I resolved to repeat them with greater precautions. Table 3 contains the data given on the plan of table 1. The first series holds for 24° ; the remaining nine series for 185°. Time is given in minutes from the period when ebullition of aniline had fairly set in; 114 C. Barus—Compressibility of Hot Water and though this cannot be sharply determined. The experiment lasted about one hour. A subsidiary table 3, contains the essential results (time, temperature 0, volume decrement w/ V, compressibility 9) of table 2, The experiment was satisfactory throughout. TABLE 2.—COMPRESSIBILITY OF WATER. sin Sa a = x 108, | Bx108. || 6,L,¢ | p. = x 108, | Bx 108. _ Atm | Atm. | | Ae i ale 0-0 ae 185° 304) 0-0 Se 13°96" | 100 3-6 A5 14:80" 100 | 9°8 cl sae 200 7:9 44 35m 200 999) Se ag 300 177 44 300 35-0 125 *185° 20 | Coney (eee 185°" At) eo 0-0 a 15°42°™ | 100 | G2eh) "T || 1458! 100} 11-7 146 18" (| 900) $4 ee) gs Vag he, 200 aes 138 ip S007) 2IEOr ae io) |. 300.) 38S huetss 185° | "90 | 7070 S(T ag5? | 0. hoon 15°17" | 100 | 7-6 95 || 1434em| 100] 12°9 161 25m 200) Cire 98 45m | 200 | 29:3 163 300 |. 278 99 || | 300] 4671 165 T85°5s Pc 0 0:0 es Re eye 20 | 070 am 15-01] 100] . 8-7 109 || 14°03] 100:| 14:7 (iguees 30" 200 | 20°6 114 °|| 50™+<| 200) *32°8 Viet 3300/2. 31-9 114 || | 300) | © 52:0) a ase oy obese 20 | 0:0: 7 ee * Commenced boiling at 0™. | 4345") 100") 18S eee i -5B™ <1 (200 1) 39-4 aes $00 |. 60-5. eneaiG 185° Threads broken off. 13°56 Measurement uncertain. 60™ ‘' Siliceous water, solid. TABLE 3.-—Hzpansion and Compressibility of Silicated water, referred to water at 24° and 20 atm. 8. gs: Bx 108. Time. ipa as. | Bx 10°. \°oPane: V ip ee | | DAS + 0 44 bs bee 185° | AA 141 40m 185° +103 req 18™ L350 267 163 | 45m 185° + 86 Si 4 25m 185° + 05 184 | 50m 185° + 5 iy 30™ 185° ea kD Papp EI 55m 185° + 60 125 35m || 185° + 99/4) Oo cec eat ones 8. The discussion of this table can be given on the lines followed in case of §6. Note at the outset that after 55™ have elapsed since exposure to 185°, the hot turbid column is not so long as the original cold clear column at 24°. The hot com- pressibility after 55™ has increased to five times the cold com- pressibility, and to three times the original hot compressibility. ats Solvent Action on Glass. 115 Some allowance must however be made for the attenuated thread of mercury (§3). If v/V be plotted as a function of p, a series of curves is obtained as shown in figure 1. Consid- ering the difficulties of measurement, they are satisfactorily regular. Temperature and time are affixed to each curve. In table 3, (v/ V) is rigorously the ratio of increment of length to the original length at 24°, due to thermal expansion and concomitant chemical action. The radius of the tubes widens as solution proceeds; but the datum (v/V) suffices for the present purposes. Let # be represented in its dependence on (v/ V). The plotted curve is a line of remarkable regularity, as shown in figure 2. It follows trom the chart that # in- creases 11/10° for each per cent of volume decrease of the water undergoing silicification. This is about 75/10° per centi- meter of length, agreeing substantially with the former result. Again v/ V decreases 13 per cent for the interval of observa- tion of 42™, or about °3 per cent per minute, thus again agree- ing with $6. See figure 3. Suppose the line for 8 and (v/ V) to be prolonged as far as (v/ V ) =180/10°, which holds for time =0. The datum for P so obtained, ought to give me the norma: compressibility of pure water at 185°. Making the prolongation, however, I find an excessively small result =50/10° nearly. This merely shows, since chemical action is very rapid, that the time at which it commenced is only roughly indicated. It is probable never- theless that £,,, will not be greater than 70/10°. Hence even above 100° the compressibility of water increases at a very low rate with temperature; at a rate about 4 that of paraftine, forinstance. Cf. figure 4. I think this indicates exceptional stability of the water molecule. 9. Now what is the underlying cause of the action described ? Clearly I think, an instability of the glass molecule at 185°, much rather than any instability of the water molecule. This is an accordance with the evidence I adduced in studying the electrolytic conduction of stressed glass,* and corresponds also to the diminished viscosity of glasst at the stated temperatures. At 185° the cohesive affinitiest of the water are sufficient to disintegrate the glass molecule. The increase of 8 with time must be due to the solution of silicate. Indeed it would be difficult to devise an experiment, in which the progress of the continued solution can be so well discerned as is possible in the present incidental results. Iam * Barus: This Journal, xxxvii, p. 339, 1889. + Barus and Strouhal: This Journal, xxxi, p. 439, 1886; ibid., xxxii, p. 181], 1886. t+ A term which will be defined succinctly in the course of the present series of papers. AM. Jour. Scl.—TuirRD SERIES, VoL. XLI, No. 242.—FEBRUARY, 1891. 8 116 C. Barus—Compressibility of Hot Water, etc. aware that the march of 8 is to be interpreted with reference to Wilhelmy’s* time law of reaction; but the discussion is somewhat involved and must be omitted. Curiously enough the effect of solution is here an increase compressibility, whereas in all other cases (§ 2), it is a decre- ment of compressibility. I leave this without comment, believing however, that the silicate during the course of the oscillations of pressure, passes through states of unstable equilibrium with its water. The apparent compressibilities measured, are really solution phenomena, since the silicate present passes from a lower to a higher state of hydration when pressure passes from the lower to the higher value. For this reason compressibility increases with the quantity of silicate present, in other words with the time during which the solvent action has been going on. Something of this kind I formerly observed in case of moist mono-chloracetic acid. The possible occurrence of lag, though I did not search for it, would be obscured by the contraction of the silicated column of water. If a reaction is superinduced in a system of solid and liquid by presssure, the curious question is thus presented whether the reaction is more complete in proportion as the acting pressure is higher; or more generally whether the final progress of the reaction, or the chemical equilibrium varies with pressure. To my knowledge in ali the relevant instances. examined (take the action of acid on zine under pressure of the gas evolved) this is true. As a general deduction from the above experiments I infer, that in many instances a definite dissociation temperature of the solid must first be surpassed, before solution will set in. Elsewhere I shall show that the recognition of this principle, regarded at the outset as a mere working hypothesis, has enabled me to effect the complete solution of a valuable class of commercial products. * Wilhelmy: Pogg. Ann., lxxxi, pp. 413, 499, 180. C. R. Van Hise—Lake Superior Stratigraphy. 117 Art. XVI.—An Attempt to harmonize some apparently conflicting Views of Lake Superior Stratigraphy ;* by ©. R. Van HIse. [Read at the Wisconsin Academy of Science, Arts and Letters, Madison, Dec. 30, 1890.] In attempting to determine how far the different views held as to Lake Superior stratigraphy are really in harmony, we have as starting planes an upper and a lower horizon. The first of these is the base of the Keweenaw Series. All are agreed that below this series is an unconformity more or less considerable. The lower of these planes lies between the crystalline schist-granite gneiss complex and the overlying elastics. Below this plane is found Ivving’s Fundamental Complex, Lawson’s Coutchiching and Laurentian, the Profs. Alexander and N. H. Winchells’ Vermilion Lake and Lauren- tian. Whether this plane is definitely fixed by a great uncon- formity will not here be discussed, as the wish is rather to dwell upon points of agreement than those of difference. That it is so fixed is maintained by Irvingt in a series of papers. Lawson? agrees with Irving that this plane is marked by a great change of conditions of deposition and a probable unconformity in Ontario. Prof. Pumpelly, who has recently made a rather extended trip in western Ontario, acquiesces in this conclusion. Of the extension of these same series in Minnesota, the Profs. Winchell,§ although recognizing this plane as the boundary between two groups of rocks, maintain conformity. Bell] now stands almost alone in the contention that this lower plane cannot be recognized. In the older work of the Canadian Survey all of the groups of rocks included between the above planes have been placed as Huronian, and * This paper is in large measure the same as the part on correlation in a memoir upon the Penokee Series of Michigan and Wisconsin to be published as a mono- graph of the U.S. Geol. Survey. For the distribution of the rock-series discussed in this paper, see Irving’s Preliminary Geological Map of the Lake Superior Region, 5th Ann. Rept. U. S. Geol. Survey, p. 181. + Copper-Bearing Rocks of Lake Superior, U. 8. Geol. Survey, Monograph V ; Divisibility of the Archaean in the Northwest, this Journal, III, xxix, pp. 237- 249, 1885; On the Classification of the Harly Cambrian and Pre-Cambrian Form- ations, U. S. Geol. Survey, Seventh Ann. Rept.; Is there a Huronian Group? This Journal, III, xxxiv, 204-249; Explanatory and Historical Note by R. D. Irving to Bulletin U. 8S. Geol. Survey No. 62, The Greenstone Schist Areas of the Menominee and Marquette Regions of Michigan, by George H. Williams. + Report on the Geology of the Rainy Lake Region, Andrew C. Lawson: Geol. and Nat. Hist. Survey of Canada, Annual Report 1887, part F, p. 141. § Geol. and Nat. Hist. Survey of Minn., 16th Ann. Rept., 1887, pp. 365-366. Ibid., 17th Ann. Rept., 1888, pp. 66-67. | The Huronian System in Canada, Robert Bell: Trans. Royal Soc. Can., 1888, vol, vi, sec. 4. 118 Van Mse— Attempt to harmonize some apparently also a part of the rocks included in Irving’s Fundamental Complex, Lawson’s Coutchiching, and Prof. Winchells’ Ver- milion Lake series. Irving* has shown conclusively that cer- tain of the rocks on the south shore of Lake Superior, first loosely placed with the Huronian are to be excluded from it. This work has been so thoroughly supplemented in the United States by the Profs. Winchell, and in Canada by Lawson that at the present time this conclusion can hardly be questioned. It is believed that many of the difficulties as to correlation in the districts about Lake Superior have largely arisen from the failure to generally recognize a physical break, which has a very wide if not universal extent in the Lake Superior region. So far as I know, the first descriptions of this break are by Foster, and Foster and Whitneyft in the Marquette district. It was next noted by Brooks.t By Rominger§ it was seen at many points which lead to the suggestion “That great disturbances of not only a local extent, must have occurred at the end of this era of iron sediments.” Wadsworth| says of it, these conglomerates ‘‘ Mark old beaches water-worn after the jasper and ore were 2m situ, in nearly their present condition, and, if the logic of the geologists of the Michigan and Wis- consin, surveys were carried out, these unconformable detrital formations would mark a new geological age.” Foster C. Whitney and Dr. Wadsworth, however, maintain- ing the eruptive origin of the jasper and ore, do not believe that the conglomerates thus mark a new geological age. The real significance of the break was recognized by Prof. Irving,4 who not only found it in the Marquette district, but knew of its equivalent in the Vermilion: Lake district of Minnesota. The break in the Marquette district was lately noted by Prof. * In papers above cited. + Report on the Minera! Lands of Lake Superior, J. W. Foster: Ex. Does., 1848-49, 2d Sess., 30th Cong., vol ii, No. 2, p. 161. Geology of the Lake Superior Land District, J. W. Foster and J. D. Whitney: Senate Docs., 1851, Spec. Sess., 32d Cong., vol. iii, No. 4, pp. 23, 43 and 67. t Iron-Bearing Rocks of the Upper Peninsula of Michigan, T. B. Brooks; Mich. Geol, Survey, 1873, vol. ii, pp. 128-129, 133. § Upper Peninsula of Michigan, C. Rominger, Mich. Geol. Survey, 1881, vol. iv, pp. 74-75. || Notes on the Geology of the Iron and Copper Districts of Lake Superior, M. E. Wadsworth: Bull. Mus. Comp. Zool., 1880, vol. vii, pp. 30-31. “| Preliminary Paper on an Investigation of the Archaean Formations of the Northwestern States, R. D. Irving: Fifth Ann. Rept. U.S. Geol. Survey, 1885, p. 193. ‘I refer to the occurrence in the quartzites overlying the ores, at several of the Marquette mines, of abundantly rounded fragments derived from the ore below. .A very much more striking occurrence of this kind is met with in the Vermilion Lake district of Minnesota, where the fragments included in the con- glomerate overlying the iron belt, are often several feet in length, and angular. That these fragments prove the existence of the jaspery and chalcedonic material in its present condition before the formation of the quartzite is sufficiently evi- dent.” ~ conflicting Views of Lake Superior Stratigraphy. 119 N. H..Winchell,* to whom it appeared so great that the rocks above it were provisionally referred to the Potsdam. It has later been more broadly recognized by Prof. Alexander Winchell, who maintains two systems have been “ confounded in the Huronian.” + Our recent studies have shown the break to be universal in the Marquette district. In order to understand fully its nature it is necessary that the facts shall be given in some detail. The greater part of the ore taken from the more prom- inent mines occurs associated with hematitic, magnetitic and actinolitie schists and jaspers. ‘This jasper is curiously banded and contorted, is often of a beautiful blood-red color, and is commonly interlaminated with iron ores. Of prominent mines among many which fall in this horizon may be mentioned the Republic and Lake Superior. Below the iron-bearing mem- ber is the lower quartzite of Brooks, which locally becomes a marble or novaculite. Above the iron- -bearing” member is Brooks’ upper quartzite.t This is in many places a pure thick quartzite which immediately overlies the ore. This quartzite, even when fine-grained, is oi the variety in which the enlarge- ment process has changed it from a sandstone to a vitreous quartzite. It shows nowhere any evidence of having been subjected to powerful dynamic action. It is at the base of this quartzite that the physical break referred to occurs. At the Goodrich Mine, just south of a large open pit, is the banded ore and jasper formation which contained small bodies of rich ore. Whe formation is exceedingly contorted, the ribboning of the jasper now running in one direction, now in another. The foot-wall of the large pit just mentioned is this jaspery formation. Locally the banding of the Jasper abuts perpendicularly against the foot-wall. This foot-wall strikes nearly in an east and west direction and dips at an angle of 60° or 70° toward the north. The rock resting upon the banded jasper, including that which has been mined for ore, 1s a conglomerate, the fragments of which are chiefly from the immediately underlying rock. These fragments vary from those which are minute, to bowlders ten ‘inches or a foot in diameter. They are all thor oughly well rounded, so that there is no question of their water-worn character. "AS indicated, they are most abundantly of the jasper and ore immediately below, and the ore, upon account of its softer character, is predominant in the matrix. Mingled with the fraginents mentioned are numerous ones of white quartz, which are *Geol. and Nat. Hist. Survey of Minnesota, 16th Annual Report, 1887, pp. 43-47. + “Two Systems confounded in the Huronian,” Am. Geol., vol. iii, pp. 212-214. { Iron-Bearing Rocks of the Upper Peninsula of Michigan, T. B. Brooks: Mich. Geol. Survey, 1873, vol. 2. p. 149. 120 Van Hise—Attempt to harmonize some apparently exactly like the white vein quartz found in the lower quartzite of Brooks and in the still lower granite-gneiss complex. The ore mined is here plainly a direct detrital product from the immediately underlying older formation. Bigw: The relations will be more clearly understood by Figs. 1 and 2. The first is from a photograph taken with the camera, pointing down upon the horizontal surface of the exposure. The manner in which the banded and contorted jasper abuts Fig. 2. JASPER AND ORE. meee QUART ZITE. SODA SRO) OK \ \ SAAN against the conglomerate is clearly shown, as well as the irregular eroded surface of the jasper at the time the conglom- 4 conflicting Views of Lake Superior Stratigraphy. 121 erate was deposited upon it. Fig. 2. is a section from south to north, showing the relations described. The coarse conglom- erate, in passing towards the north, varies into a fine con- glomerate showing fragments of the same character, and this into the ordinary vitreous quartzite of the region. Prof. N. H. Winchell’s* figure of this mine does not show that he appreciated the manner in which the banded ore and jasper abut against the conglomerate. Its lamination is figured as regular and parallel to the foot-wall of the open pit, whereas it is extremely contorted and often abuts against it, while the conglomerate is represented as dipping at a. flat angle away from the foot-wall, whereas the dip of the con- glomerate is that of this wall. | In the Goodrich locality this conglomerate belt has been traced fully a mile east and west—that is, from the Saginaw Mine, east of the Goodrich, to the Fitch Mine a considerable distance west, and was noted by Brooks at the New England Mine, about two miles east of the Goodrich. The conglomer- ate, which is here so thick and prominent, is in most other localities in the Marquette district much thinner and varies quickly into the ordinary vitreous overlying quartzite, and has therefore often escaped attention. Upon searching for it, it has been found, however, almost everywhere in the Mar- quette district, as the following lst of mines will show. At the Barron Mine near Humboldt, Mich., it is scarcely less con- spicuous than in the Saginaw Range. It-has been observed west of the Winthrop Mime; for a distance of a mile anda half or two miles along the Cascade Range, from the Cascade Mine to the Wheat; at the open pits of the Jackson Mine in Negaunee; at the Lake Superior and Barnum mines of the Ishpeming basin, as shown by diamond drill borings; at the Boston Mine, north of Clarksburgh, at the Spurr and Michi- gamme mines, near the west.end of the Marquette Range; at the Republic Mine, the terminus of a long southern tongue of the iron-bearing series; and north of the east end of the Cascade Range, about 14 or 2 miles west of Goose Lake. As pointed out by Professor Irving, since the fragments of ore, chert and jasper are found in the conglomerate in pre- cisely the condition in which they occur in the underlying for- mation with their stratification lines running in every direction, it is manifest that the latter had reached its present condition before this overlying conglomerate was deposited. Whatever the origin of this ore and jasper of the Marquette district is believed to be, it is evident that a time-break of universal extent and of great magnitude occurs above it. * Geol. and Nat. Hist. Survey of Minn., 16th Annual Report, 1887, p. 46. 122 Van Hise—Attempt to harmonize some apparently Above the upper quartzite, which is the base of the Upper Marquette Series, follow the black slates (sometimes carbon- ~ aceous), graywackes, and mica-schists, together of great thick- ness. These appear a short distance west of Negaunee; for some six or eight miles east of Lake Michigamme cover a larger area than the members of the series below the uncon- formity, and about Michigamme Lake have a great development. In these upper slates are locally belts of chert, associated with which are ore-bodies of considerable size, among which as types may be cited the Wetmore, Dalliba and Beaufort. These ores are, however, of a very different character from those which occur in the red banded jasper already described, being always soft, and oftentimes more or less limonitic. Our study has not extended far enough so that we feel certain on which side of the break some of the mines of the Marquette district occur. Among such are those of Teal Lake, which we feel inclined at present to place in the upper series. It is thus plain that in the Marquette district we have, as maintained by Brooks, at least two ore-bearing horizons; not only this, but these horizons are separated by a great uncon- formity and therefore belong to different series of rocks. Those upon the lower side of this break, in the exceedingly contorted jasper, in the schistose character of its quartzites, and in the general assumption of a semi-crystalline character. show the evidence of profound dynamic action. In the upper series, on the contrary, the folding has not been intense; the fragmental character of the slates and quartzites under the microscope is evident at a glance, and no indication of great dynamic action is seen. While subsequent to the deposition of the upper series, the whole region has been subjected to a new folding, great enough in places to give the later series a dip of 60° or 70° as at the Goodrich, it has not suffered since that time such intense dynamic movements as has produced the more thoroughly crystalline and folded character of the earlier series. Uneonformity in the Vermilion Lake district.—Near Ver- milion Lake, while we have not yet discovered the same struc- tural evidence of a physical break between the iron-bearing and an overlying newer series, there occurs a wide belt of con- glomerate which overlies the iron formation and contains very numerous fragments from that formation, as indicated by Irving in the paper already cited. A similar conglomerate, containing red jasper fragments and having a wide extent, occurs at Ogishki Manissi Lake.* This rock is also found at points intermediate between Vermilion Lake and Ogishki Manissi. * Enlargements of Hornblende Fragments, C. R. Van Hise: this Journal, III, xxx, 232, 1885. conflicting Views of Lake Superior Stratigraphy. 128 A short distance north of the Ogishki Manissi conglomerate, in Ontario, adjacent to Knife Lake on Hunter’s Island, is the extension of the Vermilion Lake iron-bearing series, carrying large bodies of ore and jasper. That the iron-bearing series of Vermilion Lake and Hunter’s Island are the source of the fragments found in these conglomerates there can be no doubt, and as the contained fragments are precisely like those found in the original position, there can be no question that the underlying series had reached its present condition before the deposition of the overlying conglomerate. We have here, then, very strong presumptive evidence of the existence of a considerable unconformity. Onconformity in the Kaninistiquia district.—Our recent work has shown that an exactly similar conglomerate is found very extensively developed in the neighborhood of Kaministi- quia, Ontario. This is associated with a series of rocks which are the exact duplicate of the Vermilion Iron-Bearing Series. The reproduction in lithological phases is more perfect between these series than between any other detached series of rocks known to us in the Lake Superior region. The Ontario rocks have been subjected to folding so as to repeat the series, in this respect only differing from the Vermilion Lake rocks. The most abundant Kaministiquia rocks are the pecu- har slates and schists, not easily described, but having charac- teristics easily recognized by any one who has studied the equiv- alent Minnesota series. These rocks, as at Vermilion Lake, con- tain abundantly the various phases of ore, chert and jasper well exposed at Tower and Ely and have an extent for many miles. The slates and schists are locally carbonaceous and graphitic as at Vermilion Lake, as for instance north of Port Arthur. The iron-bearing formation is in many places in its upper parts an iron carbonate which varies into ferruginous cherts and jaspers. These facts point to their derivation from an original cherty carbonate, as shown by Irving* to be probably true of * Origin of the Ferruginous Schists and Iron Ores of the Lake Superior Region, R. D. Irving: this Journal, III, xxxii, 267-270, 1886. Prof. N. H. Winchell and H. V. Winchell deny the derivation of the Ver- milion ores from an original iron carbonate on account of the alleged lack in that district of this material. (On a Possible Chemical Origin of the Iron Ores of the Keewatin in Minnesota: Proc. Am. Assoe. Adv. Sci., 38th meeting, 1889, pp. 235-242; Am. Geol., vol iv, pp. 291-300, 1889.) That it is there found has already been shown by Irving, and the objection wholly falls to the ground in the Kaministiquia district. Dr. M. EK. Wadsworth maintains that the Lower Marquette ores and jaspers are eruptive. (Notes on the Geology of the Iron and Copper Districts: Bull. Mus. Comp. Zool., 1880, vol. vii, pp. 28-52.) Many facts are cited to show the way in which the jasper and ore intrude the associated schist or have irruptive contacts with it. The facts, however. indicate the eruptive character of the ore and jasper only if the schists are of sedimentary origin. Our later investigations have shown that the Lower Vermilion and Lower Marquette iron-bearing members con- tain many schistose dykes, and also that in many cases the massive greenstone 124 Van Hise—Attempt to harmonize some apparently the Marquette, Vermilion Lake and other Lake Superior iron- bearing series. Here, as at Vermilion Lake and Hunter’s Island the overlying conglomerate containing the jasper frag- ments has been derived from this underlying formation. We thus can separate the Vermilion, Hunter’s Island and Kaminis- tiquia iron-bearing and associated rocks into two series, an upper and a lower, just as we have been able to divide the Marquette series into two divisions. Position of the Ogishki Manissi conglomerate.—lf the foregoing is true, it determines the place of the Ogishki Manissi conglomerate. This has been placed by Dr. Alexander Winchell* as a part of the Vermilion Lake Iron-Bearing, that is, Lower Series. Professor N. H. Winchell,t having practi- cally the same facts at his disposal has placed this conglomer- ate as probably belonging with the Animikie, and the asso- ciated slates have been given the same color as the Animikie formation on his map.¢ If, as argued above, the debris of the conglomerates is de- rived from the iron-bearing series after they have undergone profound changes, they do not belong with those series, but should be placed at an independent horizon or at the base of the Animikie. These conglomerates have been regarded by Mr. W. N. Merriam, who has done a very large amount of work in northeastern Minnesota, as a layer overlying the older formations. While the iron-bearing schists at Vermilion Lake are in a vertical attitude, the clastic layers of which the conglomerates are a part have been found on some of the islands of Vermilion Lake by Mr. Merriam to be gently folded into a series of rolls, although often having a vertical cleavage. We thus conclude, as has been thought by Irving, that at Ver- knobs of the Marquette region vary by imperceptible stages into the schists asso- ciated with the iron ore and jasper. (The Iron Ores of the Penokee-Gogebic Series of Michigan and Wisconsin, C. R. Van Hise: this Journal, III, xxxvii, 32-48, 1889; the Greenstone Schist Areas of the Menominee and Marquette Regions of Michigan, George H. Williams: Bull. U. S. Geol Survey No. 62.) The schists are then, in part at least, of eruptive origin. That these well laminated rocks should not at first be regarded as eruptive is natural, but the variation of massive igneous rocks into those which are well laminated as a re- sult of dynamic action and metasomatic changes is now so well known that new cases of it excite no surprise. I would by no means assert that all of the schist- tose rocks associated with the iron-ores and jaspers in the Marquette and Ver- milion districts to be of eruptive origin, but this is certainly the case at many localities. This view reverses Dr. Wadsworth’s and makes his sedimentary rocks eruptive and his eruptive ones sedimentary. It will, however, be seen that this position harmonizes Irving’s conclusion as to the sedimentary origin of the ores and jaspers, and the point upon which Dr. Wadsworth places most emphasis, that there are irruptive contacts between these rocks and the associated schists. *Geol. and Nat. Hist. Survey of Minnesota, 16th Ann. Rept., 1887, p. 359; Proc. Am. Assoc Adv. Sci., 38th Meeting, pp. 234, 230. + Geol. and Nat. Hist. Survey of Minnesota, 16th Ann. Rept., 1887, p. 98. t Geol. and Nat. Hist. Survey of Minnesota, 15th Ann. Rept., 1886, pp. 208-209. conflicting Views of Lake Superior eae 125 milion Lake and Ogishki Manissi Lake we have an infolded newer series resting upon older series of more crystalline rocks.* Break below Lower Marquette Series.—lt cannot be denied that the recognition of the break described disposes of some of the evidence which has been cited as proof of the break be- tween the Lower Marquette and Lower Vermilion Series and the underlying complex. Over large areas, by overlapping, the Upper Marquette Series of great thickness undoubtedly comes in contact with the Fundamental Complex. So far as local unconformities and basal conglomerates occur between these two, they only prove that the Upper Marquette Series is unconformably above the Fundamental Complex. Those who have held that the granite is later than the Marquette Series, and that the rela- tions between the two are those described by Lawson between the Laurentian and Coutchiching, will undoubtedly gain sup- port to an allied position by this fact, if so shifted as to main- tain these relations between the Laurentian and Lower Mar- quette only. Since we cannot here enter into a discussion which would occupy much space, I can only state that it yet seems to us that there is sufficient evidence for the belief that the Lower Marquette Series rests unconformably upon the Fundamental Complex; while recognizing the fact that much of the granite is intrusive in certain “ dioritic schists”? which have usuaily been regarded as belonging to the Iron-Bearing Series. The foregoing facts and relations in the Marquette, Ver- milion and Kaministiquia districts once appreciated, it imme- diately occurs to one that here is a key which will harmonize apparently discordant opinions as to Lake Superior strati- graphy. Lelations of Animikie and Vermilion Series.—In the past few years the controversy has been most keen as to the equiv- alence or non-equivalence of the Animikie and Vermilion Lake Iron-Bearing Series. Professor Irving has maintained that the Animikie Series, in its lithological character, is like the Mar- quette, the Marquette like the Vermilion, and therefore the Animikie in all probability the equivalent of both Marquette and Vermilion.t Professor Alexander Winchell having visited *Some Results of Archean Studies, Alexander Winchell: Bull. Geol. Soc. of America, vol. i, pp. 357-390; and Discussion, pp. 31-393. + Prof. Irving perfectly appreciated that the Animikie Series rests in uncon- formity (On the Classification of the Early Cambrian and Pre-Cambrian Forma- tions, R. D. Irving: U.S. Geol. Survey, 7th Ann. Rept., p. 421), upon their im- mediately underlying rae but believed that the weight of evidence to incline to the position that the Vermilion Lake iron-bearing series at some distance to the west is an infolded newer series now in apparent conformity with the older con- taining rocks, and that it is these latter which extend eastward and are found underlying the Animikie. 126 Van Hise—Attempt to harmonize some apparently the Lower Marquette Series, and seeing but little of the ground in which the Upper Marquette is found, and conse- quently not appreciating that in area and in volume this series probably surpasses the Lower Marquette, has maintained that the Marquette rocks are the equivalent of the Vermilion Lake Tron-Bearing Series, but that the Animikie Series is separated from that at Vermilion Lake by a great unconformity. He, however, appreciated that in the Marquette district are certain slates which in lithological character are like and might be equiv- alent to the Animike.* Both of these positions probably have an element of truth and an element of error. The Upper Mar- quette, Upper Vermilion, Upper Hunter’s Island (Ogishki Ma- nissi), in their lithological characters and gentle folding, are closely analogous to the Animikie, and as maintained by Irving are its probable equivalent; while the Lower Marquette and Lower Vermilion Lake, as maintained by Professor Alexander Winchell, unconformably underlie the Animikie. Whether be- tween the Kaministiquia and equivalent conglomerates, and the flat-lymg rocks of the Thunder Bay district, recognized heretofore as Animikie, there is a minor physical break, we have no sufficient evidence to give an opinion. As _ has © been noted, it has been long well known that near Port Arthur, Ontario, the Animikie and underlying Kaministi- quia Series are unconformable. Mr. Peter McKellar,; who for many years has been familiar with this region, has proved this conclusively. It has already been seen that the rock series here unconformably underlying the Animikie are identical with the Vermilion Lake Iron-Bearing Series. Con- sidering the complete likeness of this lower series with that bearing iron at Vermilion Lake, I can no longer have any doubt of the truthfulness of the conclusion as to the physical break between the Animikie and Lower Vermilion Series in northeastern Minnesota, while yet believing in the equivalence of the Animikie and Upper Vermilion. Correlation, general considerations.—We pass now to the general correlation of the Lake Superior formation lying be- tween the two planes defined at the beginning of this paper. Before it can be decided whether series so far distant from _ each other as the Dakota quartzites and the Original Huronian (separated by 800 miles) can be parallelized, it ought to be more definitely settled to what extent correlation can be made by unconformities and lithological likenessess. Professor * Geol. and Nat. Hist. Survey of Minnesota, 16th Ann. Rept., 1887, pp. 128, 357-359. + The Correlation of the Animikie and Huronian Rocks of Lake Superior, Peter McKellar: Trans. Royal Soc., Can., vol. v, sec. 4, pp. 63-73, 1887. conflicting Views of Lake Superior Stratigraphy. 127 Irving* inclined to the belief that such structural breaks as that described in the Marquette district are of great extent, and this accords with the general trend of modern structural work. From what has gone before it appears exceedingly probable that the structural break between the Upper and Lower Mar- quette is identical with that which separates, even in a more pronounced manner, the Animikie and Kaministiquia Series and the Upper and Lower Vermilion Lake Series on the other side of the Lake Superior basin. This break, being thus so strongly marked at points so far separated, would argue that it extends over a very considerable area of the Lake Superior region, not improbably from the most distant rock-series before mentioned, the Quartzites of Dakota and the Original Huro- nian of the north shore of Lake Huron. It could not be ex- pected that a like succession would be found in each of the areas parallelized, even if they all belong to the same geolog- ical series. In the first place, the rocks in some districts are not sufficiently tilted to make it certain that all of the layers are exposed. Farther, nine-tenths or more of the surface of the country over large areas is heavily covered by the drift, so that it is all but certain that formations which exist at the rock surface have not been discovered. Still farther, no satisfactory explanation has yet been made of the subordinate succession of formations in the Marquette, Felch Mountain, Menominee and Vermilion Lake districts. So it is not yet known how far the order which prevails in one of the districts is equivalent with that which prevails in another. From recent work it is proba- ble that future investigations will show that this hkeness is greater in the series below correlated than has been suspected. But even supposing the discordances are so great as the present known facts might lead one to suppose, it would not be any very strong evidence against the correlations; for it is not to be expected that the same conditions of sedimentation would prevail at all times in a geological basin 800 miles in diameter. While in one part of the basin fragmental sediments were accu- mulating, it would be very strange if it were not the case that chemical sediments or organic sediments were elsewhere accu- mulating. Below it is shown that the Penokee and Animikie Series are the geological equivalents of each other in the broad- est sense of the term. It is not necessarily true that sedimen- tation began or ended simultaneousl+ in both regions, but only that in the main they stand as time equivalents. How fara correspondence can be made out among the subordinate mem- bers of the various districts can only be determined by a de- tailed investigation of each of the areas. * On the Classification of the Early Cambrian and Pre-Cambrian Formations, R. D. Irving, U.S. Geol. Survey, Seventh Ann. Rept., p. 391. 128 Van Hise—Attempt to harmonize some apparently The Original Huronian Series.—Passing now to the Orig- inal Huronian.* Shall this series be correlated with the Upper or Lower Marquette, or is it the equivalent of both? A careful field and laboratory study of the rocks of the Original Huronian has shown it to. consist in great part (1) of frag- mental quartzites, the induration of which has been caused by the deposition of interstitial silica; (2) of graywackes and graywacke-slates (at time, conglomeratic—Logan’s slate-con- glomerates), the induration of which is due to the deposition of interstitial silica and metasomatic changes in the feldspar; (3) of cherty limestones; and (4) of eruptives. So far as yet known an iron-bearing belt is not there largely developed, although at certain localities rocks belonging to this formation are found. In its readily recognized fragmental character, in its gentle folding, and in the greatness of the break between it and the granite-gneiss complex, the Original Huronian is much more nearly analogous to the Penokee, Upper Marquette and Animikie than to the Lower Marquette and Lower Vermil- ion iron-bearing series. In the order of succession of its. subordinate members it cannot be said to correspond very closely with either the Upper Marquette and Animikie or the Lower Marquette and Lower Vermilion Lake. It, however, seems to us that its unmetamorphosed character is a guide of some importance. As pointed out by Mr. McKellar,t the intense folding to which the Vermilion Lake and Kaminis- tiquia Series have been subjected must have preceded the much more gentle synclinal movement which formed the basin of Lake Superior. That no violent squeezing has occurred since the beginning of Animikie time is known to be true of the Lake Superior Basin, and this being true, it seems exceedingly probable that the gently folded rocks of Lake Huron belong with those of like character about Lake Superior. If this is not the case, the intense dynamic movements which produced the closely folded rocks of Northeastern Minnesota and Ontario: must have lost their force before reaching the area about Lake Huron, and this region must have escaped any serious folding for a Jonger time than any other closely studied part of the earth’s crust. ; * The Original Huronian only is here compared with the series about Lake Superior because it is the area to which the term was first applied. and also be- cause it has been more thoroughly described and mapped than any other area in Canada designated by the term Huronian. How far other areas of rocks in- cluded under this term by the Canadian Survey in the past are the equivalent of this Original Huronian area is difficult to determine. That many other areas are less Huronian than the original area I would not pretend to say. Jn this con- nection see, The Huronian System in Canada, by Robert Bell, Trans. Royal Soc. Can., vol. vi, sec. 4, pp. 3-13, 1888. + L. ce. p. 88. conflicting Views of Lake Superior Stratigraphy. 129 Besides the reason already mentioned for placing the Huro- nian as the equivalent of the Animikie and Upper Marquette rather than below these series, we have one characteristic feat- ure which is of some weight. One of the most peculiar rocks of the Original Huronian is a conglomerate which carries numerous fragments of blood-red jasper. At present the source of these fragments is unknown. From what has gone before it is apparent that a jasper con- glomerate is the basal member of the Upper Marquette Series, and also that similar conglomerates occur in a like position in Ontario and northeastern Minnesota. Considering the wide- spread character of this jagpery, cherty and iron ore conglomer- ate, its occurrence in the Huronian of Lake Huron suggests that here may be found in the future an underlying series which bears this jasper in large quantity and which therefore will in position and in lithological character, be the equivalent of the Lower Vermilion and Lower Marquette iron-bearing series. * In this connection it is to be said that Mr. McKellar, in the article already cited, argues that the Animikie is newer than the Original Huronian because of the great unconformity which maintains between the Animikie series and the underly- ing schists of western Ontario which he regards as Huronian. The weak point of this argument is the assumption that those underlying schists are more nearly like the Original Huronian than are the Animikie rocks. The author states that he has not himself closely studied the Original Huronian, while the later writers who have visited both regions, including Prof. Irving and the Profs. Winchell, agree that the Original Hu- ronian is far more nearly alike, both in essential lithological character and in conditions of metamorphism, to the Animikie series, than to the folded schists of Canada and Vermilion Lake iron-bearing rocks, and with this view our later work work accords. The Sioux Quartzites, St. Louis Slates, etc.—Much of what. _has been said to show that the Original Huronian is the equiva- lent of the Animikie, Upper Vermilion and Upper Marquette applies with equal force to such rock series as the Chippewa Quartzites, the Baraboo Quartzites, the Sioux Quartzites and the St. Louis Slates. None of these series are closely folded although often, dynamic movements have developed slaty cleav- ages. Also their original fragmental character is seen under * Since this paper was written, Alexander Winchell has announced the dis- covery of an unconformity in the Original Huronian area, the ‘‘ Lower Slate Con- glomerate”’ belonging below the break, although no contacts are described. If this conclusion is correct, we have here as in other districts two series above the fundamental complex and the analogy is complete (Am. Geol., vol. vi, p. 370). 130 Van Hise—Attempt to harmonize some apparently the microscope at a glance. These series present thick beds of fragmental rocks, the induation of which has been caused by the same process ‘which vitritied the quartzites of the Original Huronian. The supposed absence of ferruginous rocks in these districts has been used in the past as an argument against the correlation of them with the Penokee and Animikie Series below considered, but this absence has no particular weight because such beds, as compared with the fragmental rocks, are insignificant in amount; and farther, it is quite possible ‘that such non-fragmental water-deposited formations may in the future be found in several or all of these districts. The prob- ability of this is rendered greater by the fact that explorations for iron have very recently developed beds of this sort between the two quartzite ranges of Baraboo and in the northward extension of the St. Louis Slates. The rocks here found are the exact parallel of the iron-bearing beds of the Penokee and other iron-bearing districts. The percentage of iron is so great in certain localities that the material is being mined for an ore. The Penokee-Gogebic and Animikie Series.—In the Penokee- (sogebic district of Michigan and Wisconsin we have the fol- lowing succession: At the base is a gneiss-granite schist com- plex. The schists are always completely crystalline, although often finely laminated or foliated. The contact of the granites and gr anite- gneisses with the crystalline schists is the irruptive one so well described by Lawson as prevailing in Ontario. Above this granite-gneiss-schist complex, and separated from it by a great unconformity, is a Cherty Limestone Member which in places is 300 feet thick. While it extends east and west many miles, it is not longitudinally continuous. Above this cherty limestone, separated by an erosion interval, is the Penokee-Gogebie series proper, which consists of a Quartz- Slate Member, the upper horizon of which is a vitreous quartz- ite, an lron-Bearing Member, and Upper Slate Member. Above the Penokee series, separated by another very considerable unconformity, is the Keweenawan Series. The parallelism between this region and the Marquette already described is at once manifest. The Penokee series proper is the equivalent of the Original Huronian, Upper Marquette and their equivalents : The Cherty Limestone Member stands as a possible equivalent of the Lower Marquette. But this correlation is of uncertain value, and, if sound, in the Penokee-Gogebie district the upper members of the equivalent of the Lower Marquette have been removed by erosion. That this is not improbable is indicated by the fact that the cherty limestone is of very considerable thickness in some places and has entirely disappeared in others, while numerous fragments of it are found in the basal member of the Penokee series proper. conflicting Views of Lake Superior Stratigraphy. 131 Farther, the relative geographical positions of the Penokee, the Upper Marquette and the Chippewa Quartzite districts are such as to strongly suggest that they were once connected. The Penokee Series at the east is cut off by the uncontormably overlying Eastern Sandstone; but east of the south end of Gogebic Lake there are here and there outcrops of slate which are like the Upper Slate Member of Penokee district, and a short distance to the east the narrow belt spreads out into the broad area of fragmental rocks of which the Marquette and Menominee districts are arms. At the west the Penokee Series has been entirely swept away by erosion, the copper-bearing rocks coming in contact with the underlying gneisses and gran- ites; but to the southwestward appears the fragmental quartz- ites of the Chippewa valley which are believed to be its continuation. The equivalency of the Penokee Series with the Animikie is as plain as the equivalency of any two areas of detached rocks in a single geological basin can possibly be in which is lacking clear paleontological evidence. It has been seen that above the Cherty Limestone of the Penokee Series is an erosion interval. In the Animikie Series we know of no equivalent to this member, and in what follows it is excluded from the discussion. The Penokee and the Animikie rocks have a parallelism in lithological characters which is most remarkable. Not only is there a general likeness between the specimens from the two districts, but almost every phase of rock from the Animikie Series can be matched by specimens from the Penokee district. In the Animikie district the for- mations underlying the iron-bearing belt are not extensively exposed, and consequently little is known of the Animikie equivalent of the Quartz-Slate of the Penokee Series. But along the Lower Current River, near Port Arthur, Ontario, quartz-slates underlying the [ron-Bearing Member are found, which resemble certain phases of the Penokee Quartz-Slate. Beginning with the iron-formations, the parallelism between the two series is almost exact. The irony beds upon Gunflint Lake, where are found the best known exposures of the forma- tion, are in their lower parts jasper, magnetite-actinolite-schist, and cherty ferruginous rocks containing more or less iron ear- bonate. Higher up are thick layers of thinly bedded cherty iron carbonate. All these varieties of rock are found in the iron-formation of the Penokee Series, and at many places the order of succession is the same. Above the iron-bearing belt in both regions is a great thickness of fragmental clay-slates and greywacke-slates which are- again practically identical in character in both districts. It is true that in the western part Am. Jour. Scl.—THIRD SERIES, VoL. XLI, No. 242.—FrEBRUARY, 1891. 9 132 Van Hise—Attempt to harmonize some apparently of the Penokee district mica-schists have developed from these slates, but the original condition of these rocks was essentially like that of the unaltered phases.* Underlying both the Animikie and the Penokee Series is a complex of granites and schists, the unconformity between which and these series is of the most pronounced character. That the Animikie Series is thus separated from the underly- ing rocks has been seen by all who have studied it. Above both series follow the Keweenaw rocks. In both regions, in passing at any place from the underlying rocks to the Kewee- naw Series in section, the two are in apparent conformity ; but, when the lines of contacts between the iron-bearing and the Keweenaw series are followed for some distance, both with the Animikie and Penokee series, this apparent conformity is found to be illusory. That is, the same member of the Keweenaw Series is now found to come in contact with one member of the underlying series and now with another, until in both regions at one or more places the entire [ron-Bearing Series is cut off, the Keweenaw rocks coming directly in contact with the basement complex.t This means that between the deposition of the Penokee and Animikie Series and the outflows of Keweenaw time there intervened a period of erosion which was sufficient in places to remove the whole of the inferior series and to cut in some places quite deeply into the Fundamental Com- lex. There is then an immense time-gap between these series and the overlying Keweenaw rocks, although this unconform- ity does not approach in the length of time involved to that separating them from the underlying schists and granites. The Animikie Series in its most typical development extend from Gunflint Lake, on the National Boundary between Minnesota and Ontario, to Thunder Bay, Lake Superior. The Penokee Series lies upon the opposite side of Lake Superior. The latter is a simple unfolded succession dipping to the north- ward under the lake; the Animikie is another such succession dipping to the southward under the same body of water. There is then little doubt, considering all the facts, that the two series represent a single period in the geological history of Lake Superior. The relations and likeness of the Penokee and the Animikie Series have been dwelt upon at length as showing the breadth of the geological basin in which the deposition of like rocks was taking place simultaneously. * Upon the Origin of the Mica-Schists and Black Mica-Slates of the Penokee- Gogebic Iron-Bearing Series, C. R. Van Hise: this Journal, III, xxxi, 453-459, 1886. + For full discussion of the proof of the unconformity between the Animikie and Keweenaw Series, see On the Classification of the Karly Cambrian and Pre-Cam- brian Formations, R. D. Irving: 7th Ann. Rept., U. 8. Geol. Survey, pp. 417-423. conflicting Views of Lake Superior Stratigraphy. 1838 The equivalency here shown is a long step in understanding the equivalency of other rocks in the Lake Superior basin. The Marquette Series.—As in the Marquette district we have already discussed in a general way the succession, it need here be merely repeated. It is as follows: At the base is a eneiss-granite complex, Lawson’s Laurentian, and this is asso- ciated with crystalline schists which are like Lawson’s Coutch- iching. The relations between these two classes are also those described as occurring between them in Ontario. In ascending order follow the Lower and Upper Marquette, having the lithological characters and relations above described. The Menominee and Kelch Mountain Series.—Passing now to the Menominee and Felch Mountain districts, our informa- tion is less exact. It is, however, clear that in both of these areas we have the Fundamental Complex; that is, the granites and gneisses associated with erystalline schists having the usual “irruptive contacts ”—the equivalents in every respect of Law- son’s combined Laurentian and Coutchiching. Above this complex Prof. Pumpelly, with whom this whole subject has been discussed and who has great familiarity with the entire Lake Superior region, suggests as exceedingly probable that in the Felch Mountain Iron-Bearing Series only the equivalent of the Lower Marquette occurs, the upper series, if it once existed, having been removed by erosion; while in the Menominee district both representatives of the Lower and Upper Marquette are present. ‘The Menominee proper—that is, that part of the area which ineludes the Chapin, Ludington and Norway mines; those in which a cherty limestone is found—are Lower Mar- quette, while the western district, including such mines as the Commonwealth, Florence and many others occurring in the upper black slate are Upper Marquette. That between these two is an unconformity is not proven, but it is a probability to be sought. The Black River Falls Series.—The Black River Falls Iron-Bearing Schists of Wisconsin have no such structural rela- tions as to enable one to determine their position. They are, however, thoroughly crystalline schists and are in vertical atti- tude. On these grounds they are placed as the equivalent of the Lower Marquette. In the districts about the Lake of the Woods and Rainy Lake, so well described by Lawson,* we have apparently, as at Felch Mountain only the two lower series of the general suc- cession, the Coutchiching-Laurentian complex ; and above this * Report on the Geology of the Lake of the Woods Region, Andrew C. Lawson, Geol. and Nat. Hist. Survey of Canada, Ann. Rept. 1885, vol. 1, new series, part CC, pp. 1-i51. Report on the Geology of the Rainy Lake Region, Andrew OC. Lawson: Geol. and Nat. Hist. Survey of Canada, Ann. Rept. 1887, part F, pp. 1-190. : 1384. Van Hise—Attempt to harmonize some apparently the Keewatin—probable equivalent of the Lower Marquette. It, however, appears that in this part of Ontario somewhat dif- ferent conditions prevail from those which occur on the south shore of Lake Superior. The irruptive contact found between the Coutchiching and Laurentian is also present between the Laurentian and Keewatin. Upon the south shore it does not appear that granitic eruptions of any magnitude have taken place since the beginning of Lower Marquette time, although in the Felch Mountain Iron-Bearing Series occurs one granitic dyke of considerable size, and it is not impossible that in the Marquette district itself some of the lower members truly belonging to the iron series are cut by granitic eruptions. We then have in the Lake Superior region the provisional arrangement for the Pre-Cambrian rocks on page 187. Nomenclature.—There still remains the question of nomen- clature. A sufficient number of terms have been suggested, and it is only necessary to ascertain which have prior right and best answer the needs of geology. The work of Lawson has made it clear that the old Laurentian must be subdivided. He retains for the igneous portion of it Laurentian, and pro- poses for the lower crystalline schist series—which he sup- poses to be fragmental, but which if so in most cases does not now reveal at all its original clastic character—the term Coutchiching. The rock series represented by these terms, as has been seen, cover large areas in Minnesota, Michigan, and Wisconsin, and the relations between the two are here the same as in Ontario. It then seems desirable to apply them broadly to the Fundamental Complex of the south as well as the north shore of Lake Superior. The only other term intro- duced for this part of the column is the Vermilion Series, equivalent to Coutchiching, proposed by the Professors Win- chell. The latter term has, however, unquestionable priority and has been more detinitely defined.* The term Keewatin was defined by Lawson to cover a series of clastics about the Lake of the Woods, and was chosen by the Professors Winchell for the Vermilion Lake iron-bearing series, which was believed by them to be the equivalent of the Original Keewatin. If this conclusion were demonstrated, it would seem proper to adopt this term to cover not only the * In this article, Vermilion Series always refers to the iron-bearing rocks and associated clastics of Vermilion Lake. This term was thus first loosely applied by Irving (Preliminary Paper on an Investigation of the Archean Formations of the Northwestern States, R. D. Irving: 5th Ann. Report, U.S. Geol. Survey, pp. 177-242.) Later it was used by the Professors Winchell to designate an under- lying series of crystalline schists. For this series, however, Lawson had previ- ously proposed the term Coutchiching. (The Internal Relations and Taxonomy of the Archean of Central Canada, Andrew C. Lawson, Bull. Geol. Soc. of Amer- ica, vol. i, p. 183, 1890.) conflicting Views of Lake Superior Stratigraphy. 135 series in these districts, but the Lower Marquette, Lower Ver- milion, Hunter’s Island and Lower Kaministiqua series. It is, however, by no means clear that the Keewatin will not prove to be a complex series just as have the Marquette and Vermil- ion Lake rocks. One other term has been proposed for this place, Marquettian,* but this term is objectionable because as used it included both Upper and Lower Marquette. Dr. Selwyn very strongly maintains that Huronian as used by the Canadian Survey includes not only the rocks designated in this paper under the term Original Huronian, but also all such series as the Keewatin, Lower Marquette, and Lower Vermilion Lake. This also accords with what has been done on the United States side of the boundary in the past, so that for the position in the general column below the Original Huronian is used Lower Huronian. Mr. Lawsont has proposed Ontarian to cover the Keewatin and Coutchiching. It appears to us that this term is unneces- sary, and that the purposes of geology are better subserved by using the term Algonkian to cover all the clastic series between the Fundamental Complex and the Cambrian, and to retain Archean as a term of codrdinate value with this for the under- lying complex. | Dr. Selwyn and Professor N. H. Winchell maintaint that the Keweenawan and. Animikie are properly Cambrian. Whether the term Cambrian shall be so extended downward as to cover two great unconformities and two additional rock series of very great thickness is purely a matter of policy and of nomenclature. While it is of primary importance that an agreement shall be reached as to the actual rock successions in the Lake Superior region and their equivalence, it is but a sec- ondary matter as to the names which shall be applied to them. That fossils are found in the Huronian is not sufficient evidence that the Cambrian shall be extended downward indefinitely. That the evidences of abundant life are here found has been long known. Many of the slates heretofore called Huronian on the south shore of Lake Superior not only contain graphitic material, but a considerable percentage of hydrocarbons. In the Animikie, on the north shore of Lake Superior, it is said that in certain mines and openings rock gas forms in consider- * Geol. and Nat. Hist. Survey of Minn., 16th Ann. Rept., 1887, pp. 365, 366. + The Internal Relations and Taxonomy of the Archean of Central Canada, Andrew ©. Lawson, Bull. Geol. Soc. of America, vol. i, pp..175-192, 1890. U.S. Geol. Survey, 10th Ann. Rept., Report of the Director. The Pre-Cambrian Rocks of the Black Hills, C. R. Van Hise, Bull. Geol. Soe. of America, vol. i, foot-note p. 238, 1890. { Tracks of organie origin in rocks of the Animikie group, A. R. C. Selwyn: this Journal, III, xxxix, 145-147, 1890, with Geol. and Nat. Hist. Survey of Minn., 17th Annual Report, 1888, p. 68. 136 ©. R. Van Hise—Lake Superior Stratigraphy. able amount. Also small quantities of rock may even be ob- tained which will burn. These substances must result from the ordinary processes which produced rock gas and coal in the rocks of far laterage. In the Sioux quartzites one unquestion- able fossil has been discovered by Professor N. H. Winchell :* a discovery of a fossil has been announced by Dr. Selwynt as occurring in the Animikie. It is a hope that in the future numerous other fossils will be found in these series, so that we may have the assistance of paleontology in Lake Superior stratigraphy. Until, however, a fauna is known in this region which is distinctly Cambrian, the discovery of life or of certain fossils in the Keweenawan and Huronian rocks is wholly insufficient evidence for placing them with the Cam- brian. The Cambrian fauna in development is fully half way up the life column. Just as another period of life has suc- ceeded the Cambrian, another has preceded it. The progress of paleontological knowledge has of late been downward. Before there was a recognized Cambrian there was a well known Silurian, and it is probable that as we become familiar with all parts of the world, other faune will be discovered below the Cambrian as distinctive in character as the Cam- brian is from the Silurian. When this is done, we shall have definite means to correlate rock series which occur in different parts of the world in the great time place represented by the Algonkian.t Thave no expectation that the above provisional succession and correlation for the Lake Superior region will prove to be accurate in all details. To a certain extent it is based upon a large number of facts and may be considered as true with a reasonable degree of probability. Another part is based upon facts of a more general nature and therefore has a correspond- ing uncertainty. It is, however, believed that there is in reality a much greater degree of harmony than has been thought in the conclusions which the various writers have held most steadfastly as to Lake Superior stratigraphy. * Geol. and Nat. History Survey of Minn., 13th Annual Report, 1884, pp. 68-72. + Tracks of Organic Origin in rocks of the Animikie group, A. R. C. Selwyn: this Journal, II], xxxix, 145-147, 1890. t For a fuller discussion of the subject of this paragraph see “‘On the Classifi- cation of the Early Cambrian and Pre-Cambrian Formations,” R. D. Irving, U. 8. Geol. Survey, 7th Ann. Rept., pp. 448-454. " | lowes ooo Western *Northern aa Michigan and ‘ | Dakota an Ontario. Minnesota. Michigan. Wisconsin. Wisconsin. Southern | Minnesota. Marquette Felch Mountain.| Menominee +Penokee- ‘ ? Gogebic. Keweenawan. Nipigon. Keweenawan, 5 mie Keweenawan. Keweenawan. Unconformity. | Unconformity. | Unconformity. Unconformity. | Unconformity. Chippewa eae eee ana e ones ars Quartzites. an akota Mgonuiat Me OpeweNe io Ueber | eand MePrer, Western Penokee- 3 Quarizites; Huronian, Kaministiquia. Vermilion. eens Wifegatebatse, © PEKING ENO) eI, Baraboo by fossilifer- Quartzites. ous series. wha, : ‘ ‘ Inferred Hrosion . Unconformity. | Unconformity. | Unconformity. | Unconformity. Unconformity. Tnterval. Unconformity. Keewatin in : Black River Lower part at least, Lower Lower Helen Mowntet Menominee ON Falls Huronian. and Lower Vermilion. Marquette. ne eae ee Proper. ae Iron-Bearing Kaministiquia. erles. (2) Schists (?) Unconformity. | Unconformity ?) Unconformity ?} Unconformity. | Unconformity. Unconformity. | Unconformity. eee a Coutchiching. | Coutchiching. | Coutchiching. Southern = Te eI Bis Complex. Eruptive Eruptive Eruptive : (Separated in ; : Archean. DMOOHEOR TINY iOfaciaalinanainr: (Hinearnisen attire Fundamental | Fundamental | Fundamental | mapping into | Fundamental | Minnesota Complex. Complex Complex. fine-grained Complex. /|River Valley = =a = Te schist, Coutch- Gneiss and (Not yet separa-/(Not yet separa- (Not yet separa-jiching,and gran-|(Not yet separa-| Granite. ted in mapping.) ted in mapping.) ted in mapping.)|ites and granite-|ted in mapping.) Laurentian. Laurentian. Laurentian. STAR dnowe ing characteris- tic irruptive contact, — Ses eo]. Surve * Thie succession is analogous to that given by Dr. Alexander Winchell (Som2 Results of Archean Studies excent that the great Vermilion and Ogishki series of slat and associated rocks, while the cryst +The Penokee Iron-Bearing es and conglomerates would be placed by him in the alline schists are designated by Coutchiching. : eries of Michigan and Wisconsin, R, D. Irving and C. R. Van Hise. Monograph 16 U.S. Geol. Survey; Abstract of same, 10th Ann, Rept,. U.S. K Alexander Winchell; Bull. Geol. Soc of America, 1890, vol. i, p. 389), eewatin. Vermilion series aS we use it applies to the iron-bearing 1388 OW. Hl. Melville—Powellite:: Calcium Molybdate. Art. XVIL—Powellite—Calcium Molybdate: A new min- eral Species; by W. H. MELVILLE. ATTENTION has been recently called in mining journals to a locality in the western part of Idaho known as the “Seven Devils” where mining operations for some time past have been actively conducted. “The ‘Seven Devils’ about ninety miles due north of Huntington and fifteen miles east of Snake River form a high broken chain of mountains nearly 9,000 feet above the sea level. The mineral zone is about one mile wide by four miles in length.”* The ore is worked for copper and silver, and is mainly the mineral bornite, a sulphide of copper and iron. “The formation on the west of the vein of ore is syenite and quartzite, while on the east wall is a soft white granite. A short distance to the east is a lime contact which extends south for some four miles, and forms a contact with granite. Along this contact some very good chimneys of ore have been discovered.” This bornite carries silver varying in quantity from 12 to 20 ounces to the ton. In one sample of very pure bornite Mr. R. L. Packard found by assay 14 ounces of silver to the ton. A sample from which I had separated for the most part the other mineral constituents gave me 15°65 ounces of silver to the ton. It was this latter fragment of bornite, weighing about 60 grams, which Mr. Packard picked up from a dump before one of the tunnels in the mining claim called Peacock and which through this gentleman’s kindness furnished the material for this paper. The specimen had evidently been exposed to weathering processes and had become friable to such an extent that between the fingers it could be crushed by slight pressure. There were two. associated minerals, one of which was identified by the following partial analysis as a lime-alumina iron garnet. It was light brown, but not erystallized. It fused easily to a black glass. Loss omignitiond 2 27.22.22. | Dbiper ce ph 6 Pali Scie aay Ae Sogn 38°67 PALO) oe met ee ge ees ee 10°08 Md O2. mea pee) Fe) 16-00 Pe)... 2 5 sues Ree era. 2 a u'91 AOR =. aERe: Fee 2 Sa eh 33°35 MgO _- Be ae 5. Tee Oa CuiOl es 2 Bae. ees eae trace 99°84 * Quotations from Engineering and Mining Journal, Noy. 22, 1890. W. H. Melville—Powellite: Calcium Molybdate. 189 Crystallized dark brown garnet is found in considerable abundance throughout this locality. The erystals exhibit the usual combination of rhombic dodecahedron and _ tetragonal trisoctahedron. That which proved to be the most important constituent of the specimen, about 1°5 grams, somewhat resembled scheelite at first sight, but a careful study of its characters excluded that mineral species from consideration. The strong reactions for molybdenum suggested a new species. The mineral was well erystallized and easily detached in almost absolutely pure con- dition from its friable matrix. Angular measurements were obtained on a number of crystals, from which the erystallo- graphic elements were calculated. The 1. fundamental angle (111) 4 (111) was O04 chosen because of its great accuracy, x the signals on the goniometer being per- fectly reflected from these planes. Other angles were read oftentimes between reflected signal and reflected light, and \\ again between merely reflected light from the erystal faces. The best crystals were about 0:04 (1™™) long, and others attained the maximum length of 0:10 inch. It was found that the crystals belonged to the pyra- midal (tetragonal) system of crystallization, and were closely allied in habit and development to scheelite. In the following table of measurements this analogy is shown. Powellite. » Scheelite.* Qe 1: 1-5445 12 TSH) Between normals. Observed. Calculated. ies ML AB WO fundamental NOS ON 1114001 G4 al 65° 247 65° 16° AEG 79° 562” SO Ne (Oe Bee LOL ~ 104 Gb. 557 65° 51” 66° 67 ON Ay et 40° 14’ AO ealZ 39° 587” From this comparison of angles and axial ratio it is evident that sharp and accurate observations must be obtained in order to distinguish by erystallographic means alone between these two species. Many crystals were examined and many trials were necessary before any difference in these angles from those of scheelite could be made out. The following forms were observed: {001} cna: ca:c ) PEPER Va ave {100} “a: ease Oy ea 1) Gis ode Small rudimentary planes appear on some crystals at the lower portion of the combination edges (111) (101), thus sug- * Dana’s System of Mineralogy, 1883, p. 605. 140 W. H. Melville—Powellite: Calcium Molybdate. gesting hemihedrism as in scheelite. Indeed the curved surface which often replaces these edges, giving the appearance of fused edges, adds greatly to the evidence in favor of this sup- position. No cleavage planes could be developed by mechanical means, yet occasionally fragments exhibited interrupted planes similar to cleavage surfaces. Hardness less than scheelite, about 3°5. Sp. gr. 4526, mean of two determinations. Color yellow with a decided green tinge. Luster resinous. Crystals semi-trans- parent. Brittle. The blowpipe characters are those ordinarily given under molybdates and tungstates, although the reactions of molybdenum in this case obscure those of tungsten asso- ciated with it. The mineral fuses at about 5 to a gray mass. Decomposed by nitric and hydrochloric acids. With Powellite was associated an olive-green substance which without doubt resulted from the decomposition of cal- cium molybdate perhaps by water holding carbonic acid in solution, whereby molybdic ochre was formed. The following analysis shows the unusual replacement of a part of the molybdic acid by tungstic acid. Rose’s method of separating these acids was adopted, and abundant tests proved the purity of the respective products of separation. Molyb- denum trisulphide was coliected by reverse filtration and ali- quot portions were taken for reduction. The molybdenum was weighed first as disulphide, and this weight was checked by reduction to metal in hydrogen gas by strong and long con- tinued ignition. Mercurous tungstate was precipitated, then ignited, and tungstic acid was finally weighed. ANALYSIS OF POWELLITE. CaO required. MoO: 1. Saat ame 58584 22°79 VIO Lae Oe mers 10-28 2:48 SiO. Bie Fae eas ee OaO>3. Uae ee DAS) 25°28 MeQ.e 2 ian Se ee ee 0°16 A e15" oo 9456 4525252555% o 65 REA antsy so yet race Cud 12a I A trace re more eee OPiS) has VO A undetermined 99°47 % Calcium molybdate has never before been observed in nature, and although the mineral under discussion contains some calcium tungstate,—according to analysis a little less than one molecule to eight molecules of calcium molybdate,— yet the molybdate is now established asa species. It fills a gap heretofore existing in the series of isomorphous minerals F. Waldo—Briickner’s Klimaschwankungen. 141 of which scheelite is the type. If the natural molybdate and tungstate of lime have the same molecular volume.as is most probable, then the sp. gr. of pure CaMoO, should be 200+46°9 = 4-967, if the molecular volume, 288 + 6:14 = 46°9, is true for scheelite. By means of the equation for the determination of the sp. gr. of one constituent of a mixture containing two substances of which one is known, the sp. gr. of CaMoQ, is 4-3465 assuming the sp. gr. of CaWO, to be 6:14 and that of the mixture 4°526 (sp. gr. of powellite). This close agree- ment in these two caleulations of the sp. gr. of CaMoO, is an interesting and important confirmation of the chemical and physical data which are given above. When this investigation was nearly completed my attention was called to a recent paper by H. Traube* in which was dis- cussed the influence of certain varying quantities of molybdic acid in scheelite upon the physical constants, namely, sp. gr. and axial ratio. The following scheme is interesting in that it illustrates those variations which different proportions of iso- morphous mixtures of CaWO, and CaMoO, produce. No mathematical law seems to exist which will express these tran- sitions. CaMoO, Powellite Scheelite CaWO, ————— —~\ S. W. Africa. Zinnwald. ( (2) %ZMoO, = 72 58°58 8:09 8°23 1°92 O 7°63 Sp. gr. 4:267 4526 5°96 5°88 6:06 6°14 Gey Wl-5458} 15 1:5445) 125840 = load I take pleasure in naming this new mineral species in honor of Major J. W. Powell, Director of the United States Geo- logical Survey. Chemical Laboratory of the U. S. Geological Survey, Washington, D. C., December 11th, 1890. Art. XVIIL—Briickner’s Klumaschwankungen ; by FRANK WALDO. Dr. EDWARD BRUCKNER, the youthful professor of Physical Geography at the University of Berne, has devoted three years to the gathering together and discussion of data concern- ing oscillations of climate as shown by direct observations * Neues Jahrbuch fiir Mineralogie, Beilage-Band, vii, Heft 2, 1890. + 1. Th, Hiortdahl, Zeitschr. f. Kryst. xii, 413, 1887. t Neues Jahrbuch, Beilage-Band, vii. 142 ff. Waldo—Brickner’s K limaschwankungen. instituted by man. His book,* which contains the results of his investigation, is a real contribution to the steady advance- ment of our knowledge of the subject, and is not merely the working out of a theory based upon an hypothesis which may be at any time overthrown by new discoveries or new ideas. The amount of work necessary to present the matter in the shape given by Dr. Briickner can be judged only by those who have undertaken researches of the same nature, but, as may confidently be said, of less extent. The sub-topies of the book are : Chapter I. The present condition of the question. Chapt. IL. Oscillations of the Caspian Sea. Chapt. III. The secular oscil- lations of lakes having no outlet. Chapt. IV. The secular oscillations of rivers and lakes with outlets. Chapt. V. Secular oscillations of rain-fall. Chapt. VI. Secular oscillations of. air- pressure. Chapt. VII. Secular oscillations of temperature. Chapt. VIII. Periodicity of oscillations of climate, derived from obser- vations of river ice, dates of the grape harvest, and the frequency of severe winters. Chapt. IX. The significance of oscillations of climate for theoretical and practical purposes. Chapt. X. Oscil- lations of climate of diluvial times, Neview of the results ob- tained. _ Graphical presentations. In the general statement of the work that had been pre- viously done, as given in Chapt. I, we obtain a good idea of the extent of the preliminary work done by the author in preparing for his own investigations. The most important literature is certainly embraced in the several hundred titles referred to, and the very condensed summary of the main results of each (pertaining to the question under discussion) shows a good grasp of the matter. In some cases, however, minor and comparatively unimportant contributions are men- tioned with the same degree of deference as that given to very exhaustive pieces of work, and without an actual reference to the works themselves the reader may be misled into giving too much weight to the contradictions of the latter by the former. In carrying out his own work, Dr. Briickner has given most valuable critical opinions of the materials and studies on which he has based his researches; and his estimates of their individual worth are the results of painstaking and in most cases time-consuming investigations. As a final table of the oscillations of the surface of the Caspian Sea, Briickner gives : * Klimaschwankungen seit 1700 von Dr. Eduard Brickner, Penck’s Geograph- ische Abhaudlungen, Band IV, Heft 2, Wien, 1890, (Ed. Holzel.) F. Walda—Briickner’s Klimaschwankungen. 148 Year. Amount in Meters. Year. Amount in Meters. 1 Siea i as pes peer + °40 SS QV ees + 88 1843/46 yay ees to —0Q-59 under this. 12 century ----- — 42 SAN ae tee eee + 0°22 higher than this, HSOG/OT. 2-3: _~+11°2 falling 1809/14-1845 RGM a Megs sian aa + 49 Soi Soma ee —0°21 falling 1847-1856/60 1715/20 _about + 03 ISS /O0EEs Bese —0°27 rising 1845-1847 1715/43 Se a rising 1861/65 Le ys See —0'19 1744/66___.__- falling LSGGWO oe ae ae +0°19 rising 1866-1878 MGs, SOM 2 “inerals Collected by Mr. Niven. Hyalite, the finest an © ve yet had, Topaz Crystals, afewr two inches long. Opal-Agate, richly colore. y banded. Smithsonites from New Me. .ich blue-green and well erpeealliced: Caledonite, Cubical Yellow Wulfenite, Flos Ferri, Turquois, &c.; New Mexico. Brochantite, Aurichalite, Chalcotrichites and Brown, barrel-shaped Vana- dinites from Arizona. Large Beryl Gestals from New Hampshire. Zeolites, the best we have had, from Nova Scotia. Microlites, a small lot from Virginia. Patterson, N. J., Zeolites, including extra good Datolite crystals, Prehnite, Heulandite in loose crystals, Quartz pseudomorphs after Pectolite, &e. Pyromorphites from Ems, about 70 choice specimens, the result of nine years careful collecting by our agent at the locality. Other Minerals from Germany: Pyrolusite, well-crystallized, Anglesite, Fhodochrosite, Gothite, Linneite, Sphalerite, Boracite—all the foregoing in good crystals. From England.—A large and fine shipment of Iridescent Pyrite on Calcite, Cassiterite crystals, Twin Calcites, Stark & Bigrigg Mine Calcites, Blue Barites, Kidney Ore, Iridescent Dolomite, Marcasite balls, Aragonite crys- tals, Fluorite crystals, Native Bismuth, Childrenite crystals, &c. Many other Important Additions, too numerous to more than mention, in- clude a few of the finest Vanadinites and Descloizites we have had ; Calcites and Rich Rose Quartz from Dakota; Jade in choice polished slabs from New Zealand ; Tourmaline sections, polished, from Brazil, very rich 1 in color; Millerites, Siderites, &c., from Antwerp, N. Y.; &c., &c. Williams’ ‘‘ Elements of Crystallography,” only $1.25 (postage 10c.) to our customers. Our 100 pp. Illustrated Catalogue, paper bound, 15c., cloth bound, 25c. GEO. L. ENGLISH & CO., Mineralogists, Removed to 733 & 735 Broadway, New York. } CONTENTS. Art. XI—A Solution of the Aurora Problem; by Frank HH. BIGELOW, 2209225 k Bee 22 See XII.—Columbite and Tartalite from the Black Hills of South Dakota; by W. P. Heapprn.._.._.-.--..-2.5) 89 XIldis.—Notes on the Geology of the Florida Phosphate De- posits 5 ‘by N. TE Darron 2222) 25) a eee 102 XIII.—Record of a deep Well at Lake’ Worth, southern © Florida; by N: He DaRTony.. 2% 1-3 eee 105 XIV.—Chemical Composition of Aurichalcite; by S. L. PENFIELD (2225407 te ee ee ee eee 106 XV.—Compressibility of Hot Water and its Solvent Action on Glass; by. Cag. Barus >=. 3 222.) 22 ee ea A. ere to harmonize some apparently conflicting Views of Lake Superior Stratigraphy ; by C. R. Van Hage oe eS ee) ee ee 1 XVII.—Powellite—Calcium Molybdate: A new Mineral Species; by W. HH. Mutyu.re 2222 3 eee 138 XVIIL —Briickner’s Klimaschwankungen ; by F. Waxpo -- 141 XIX.—Apprnpix.—Gigantic Ceratopside or horned Dino- saurs of North America; byO. C. Marsa. (Plates I—X.) 167 SCIENTIFIC INTELLIGENCE. Chemistry and Physics —Law of Osmotic Pressure, PLANCK, 151.—Osmotic Ex- periment, Nernst: Determinations of Molecular Mass by means of Solid Solutions, vANT Horr, 152.—Properties of Liquid Chlorine, KNistTscH: Preparation of Chromium by means of Magnesium, GLATZEL, 153.—Production of Urea from Albumin, DRECHSEL: Azoimide or Hydrazcic acid, CURTIUS, 154.—New Method of obtaining the Compressibility and Dilatation of Gases, E. H. AMAGAT: Mechanical equivalent of heat by method of heat radia- tion, J. SAHULKA, 155.—Electrical waves in open circuit, A. EHLSAs: Electrical waves, ERNEST LECHER: Electrical Gyroscope designed for recti- fication of the mariner’s Compass: Periodicity of the Aurora, M. A. VEEDER, 156. Geology and Mineralogy.—Ninth Annual Report of the United States Geological Survey to the Secretary of the Interior, 1887-88, J. W. PowELL, 157.—Forma- tion of Travertine and siliceous Sinter by the Vegetation of Hot Springs, W. H. WEED, 158.—Geological Survey of Illinois, A. H. WortTHen, 159.— Geological Society of America: Geology of the Marquette Iron Region, T.- B. Brooks, 160.—Harmotome from the vicinity of Port Arthur, Ontario, W. F. FERRIER: Long Island Sound in the Quaternary Era, J. D. Dana, 161. Botany.—Neue Untersuchungen iiber den Blithenanschluss, Karu SCHUMANN, 162.—Plante Kuropez, Enumeratio systematica et synonymica plantarum phanerogamicarum in Europa sponte crescentium vel mere inquilinarum, -K. RICHTER: Notes on Corticium Cakesii, B. & C., and Michanera Artocreas, B. & C., G. J. PEIRCE, 163.—Recherches sur Vorigine morphologique du Kiber interne, M. LAMOUNETTE, 164.—Die Gattung Phyllostyion und ihre Beziehungen za Samaroceltis, P. FAUBERT: Eine Notiz aber. das Verhalten-der Chloro- phyllbander in den Zygoten der Spirogyraarten, V. CHMIELEVSKY, 166. a A i ee cn ao a Oe S: Geological wae f VoL. XL eS he : Core 1991. Established by BENJAMIN SILLIMAN in 1818. ‘ JOURNAL OF SCIENCE. EDITORS JAMES D. anp EDWARD 5. DANA. ASSOCIATE EDITORS Prorressors JOSIAH P. COOKE, GEORGE L. GOODALE | ann JOHN TROWBRIDGE, or CamsrinGE. . ‘ Prorussors H. A. NEWTON anv A. E. VERRILL, oF New Haven, THE AMERICAN Proressor GEORGE F. BARKER, or PuimaDELpHia. s THIRD SERIES. VOL. XLI—[WHOLE NUMBER, CXLL} No. 243.—MARGH, 1891. WITH PLATES XI-XIV. NEW HAVEN, CONN.: J. D. & E. 8. DANA. 1891. TUTTLE, MOREHOUSE & TAYLOR, PRINTERS, 371 STATE STREET., | AT ES PR SF OS Ee a eS BS eS RS ET Published monthly. Six dollars per year (postage prepaid). $6. 40 to foreign sub- seribers of countries in the Postal Union. Remittances should be made either by money orders, registered letters, or bank checks. PINK GARNETS ! !—Intelligence has just reached us from Mr. Niven that he has made a big strike of these new and wonderfully beautiful Mexican Garnets. Until now we have had ten orders for every crystal we could get. We hope inside of a month to be able to fill all orders. The color is a delicate pink, the crystals good sized (averaging an inch in diameter) and of the rhombic dodecahedron form. Particulars can be better given next month. $306.00 OPAL.—We are assured by the owner of the mine in Aus- tralia from whom we secured this magnificent specimen, that it is the largest and finest ever discovered. The predominating color is a deep, rich oe ane the brilliant green which plays through the blue is truly wonderful, Extra Fine Silver Minerals now in Stock. Mr. Niven’s present Mexican trip has been yielding us some really remark- able specimens. It is not unlikely that a new selenium-silver species will be announced shortly. Several splendid Pyrargyrite specimens are already in —two at $50.00 each ; also a number of very choice Argentite crystals, Poly- basite crystals, Stephanite crystals, Embolite crystals, and lodyrite. Other Extra Fine Mexican Minerals Collected by Mr. Niven. Hyalite, the finest and largest we have yet had. Topaz Crystals, a few of them nearly two inches long. Opal-Agate, richly colored and finely banded. Smithsonites from New Mexico, rich blue-green and well crystallized. eee Cubical Yellow Wulfenite, Flos Ferri, Turquois, &c., New exico. Brochantite, Aurichalite, Chalcotrichites and Brown, barrel-shaped Vana- dinites from Arizona. ‘Large Beryl Crystals from New Hampshire. Zeolites, the best we have had, from Nova Scotia. Microlites, a small lot from Virginia. Patterson, N. J., Zeolites, including extra good Datolite crystals, Prehnite, Heulandite in loose crystals, Quartz pseudomorphs after Pectolite, &c. Pyromorphites from Ems, about 70 choice specimens, the result of nine years careful collecting by our agent at the locality. ; Other Minerals from Germany: Pyrolusite, well-crystallized, Anglesite, Rhodochrosite, Gothite, Linneite, Sphalerite, Boracite—all the foregoing in good crystals. From England.—A large and fine shipment of Iridescent Pyrite on Calcite, Cassiterite crystals, Twin Calcites, Stark & Bigrigg Mine Calcites, Blue Barites, Kidney Ore, Iridescent Dolomite, Marcasite balls, Aragonite crys- tals, Fluorite crystals, Native Bismuth, Childrenite crystals, &c. Many other Important Additions, too numerous to more than mention, in- clude a few of the finest Vanadinites and Descloizites we have had; Calcites and Rich Rose Quartz from Dakota; Jade in choice polished slabs»from New Zealand ; Tourmaline sections, polished, from Brazil, very rich in color; Millerites, Siderites, &c., from Antwerp, N. Y.; &c., &c. Williams’ ‘‘ Elements of Crystallography,” only $1.25 (postage 10c.) to our customers. ‘ Our 100 pp. Illustrated Catalogue, paper bound, 1oc., cloth bound, 5c. . GEO. L. ENGLISH & CO., Mineralogists, Removed to 733 & 735 Broadway, New York. THE AMERICAN JOURNAL OF SCIENCE [THIRD SERIES.] Oe Art. XX.—On Gold-colored Allotropie Silver; by M. Camive tus Ceart with 3 Plates.\* THE object of the present paper (which may be considered as a continuation of that published in this Journal for June, 1889) will be: 1st. To describe the reactions of gold-colored allotropic silver. 2d. To show that there exists a well characterized form of silver intermediate between the allotropic silver previously described and ordinary silver, differing in a marked way from both. - 8d. To prove that all the forms of energy act upon allotropic silver, converting it either into ordinary silver or into the intermediate form. Mechanical force (shearing stress) and high tension electricity convert it directly into ordinary silver. Heat and chemical action convert it first into the intermediate form, then into ordinary silver. The action of light is to pro- duce the intermediate form only, and even the most prolonged action at ordinary temperatures does not carry it beyond this. 4th. To show that there exists a remarkable parallelism between the action of these forms of force on allotropic silver and their action on the silver haloids, indicating that it is not improbable that in these haloids silver may exist in the allo- tropic condition. REACTIONS. The most characteristic reactions of gold-colored allotropic silver are those with the strong acids. When normal silver * Numbered J, IJ, III, being Plates XI, XII, XIII of the volume. Am. Jour. Sc1.—THIRD SERIES, VoL. XLI, No. 243.—Marcu, 1891. 180 M. C. Lea—Gold-colored Allotropic Silver. reduced with milk sugar and alkaline hydroxide is left in con- tact with strong hydrochlorie¢ acid even for several hours there is no action, and the silver after thorough washing dissolves in warm dilute nitric acid without residue. With allotropic sil- ver similarly treated chloride is always formed. But strong hydrochloric acid instantly converts allotropic to ordinary sil- ver and consequently only a trace of chloride is produced. By largely diluting the acid the conversion is retarded and the proportion of chloride is greatly increased. Thus for example when ordinary hydrochloric acid is diluted with fifty times its volume of water and is made to act on allotropic silver, about one-third of the latter is converted to chloride. Probably the whole would be but for the simultaneous conversion to normal silver. This double action is very curious and strongly differ- entiates allotropic from ordinary silver. Even with the same acid diluted with a hundred times its volume of water, there is a gradual but complete conversion to white silver accompanied by the production of a not inconsiderable quantity of silver chloride. Neutral chlorides also act strongly upon allotropic silver even when much diluted. So sensitive is this form of silver to the action of chlorides that if in washing it on the filter, river water containing a mere trace of chlorides is by an oversight used instead of distilled water, a thin gray film of normal silver will form on the surface. | The reactions above described were obtained with the moist precipitate freshly prepared. By standing for some time even if kept moist it appears to undergo a change. When freshly prepared it is slightly soluble in acetic acid but after standing for a week or two ceases to be so. Sulphuric acid diluted with fifty times its volume of water has no action upon normal silver. When made to act upon allotropic silver, it quickly converts it to normal but at the same time dissolves a little of it. It is rather curious that the dry film of gold-colored allo- tropic silver seems to be more easily acted upon by some reagents than the moist precipitate. I have noticed for exam- ple that oxalic, citric and tartaric acids do not convert the moist precipitate to normal silver, but films on pure paper are gradually whitened by these acids. It is not a question of strength of solntion, for the moist precipitate remained un- changed for twenty-four hours- under the same solution which whitened the same material as a dry film. Ammonia seems to be without converting action but dis- solves a trace. It will be shown in a future paper that there exists a form of allotropic silver abundantly soluble in ammonia. M. C. Lea—Gold-colored Allotropic Silver. 181 In those reactions in which allotropic silver acts the part of a reducing agent, as for example with potassium ferricyanide and permanganate and with ferric chloride, etc. its behavior differs from that of ordinary silver chiefly in showing greater activity. The difference is rather of degree than of kind. The formation by these reagents of colored films will be de- scribed at the end of this paper. INTERMEDIATE Form. Allotropic silver presents itself in an almost endless variety of forms and eolors, gold-colored, copper-colored, blue and bluish green (these last in thin films red or purple). Most of these varieties seem to be capable of existing in two conditions, of which one is more active than the other. If we coat a chemically clean glass plate with a film of gold- colored allotropic silver, let it dry, first in the air, then for an hour or two in a stove at 100° C., and then heat the middle of the plate carefully over a spirit Jamp, we shall obtain with sufficient heat a circle of whitish gray with a bright, lustrous, golden yellow ring round it, somewhat lighter and brighter than the portion of the plate that has not been changed by heat. This ring consists of what I propose to call the “ inter. mediate form.” Its properties are better seen by using a film formed on pure paper, one end of which is heated over a spirit lamp to a tem- perature just below that at which paper scorches. The change is sudden and passes over the heated portion of the surface like a flash. Examining the changed part, we find : Ist. That it has changed from a deep gold to a bright yellow gold color. 2d. When subjected to a shearing stress it does not whiten or change color in the slightest degree. 3d. It is much harder, as is readily perceived in burnish- ing it. 4th. It no longer shows the color reaction with potassium ferricyanide and ferric chloride, changing only by a slight deepening of color. Of these characteristic changes the second is the most remarkable. ‘The gold-colored silver in its original condition changes with singular facility to white silver: almost any touch, any friction, effects the conversion. If the paper on which a film is spread, is creased, the crease is found to be gray. Exposure to heat or to light destroys this capacity for change, and it is often lost by mere standing (even though pro- tected from light) for a few weeks. This evidently indicates some remarkable molecular change. It will be noticed that the anomaly lies in this, that pressure instantly effects the 182 M. C. Lea—Gold-colored Allotropic Silver. complete change from the original form to normal silver, heat effects the same change but with an intermediate stage at which stage pressure no longer produces any action. The intermediate form is distinguished from normal silver almost solely by its bright yellow color and its higher luster. This last difference is very striking when a film on glass is heated in the manner above described. The central parts in changing to white silver become wholly lusterless, while the circle of “intermediate” retains all its original luster. Its continuity is still complete, so that if viewed through the glass, it still acts as a mirror. This change may be either molecular or depend on dehy- dration. The latter seems doubtful for the change can not be brought about by desiccation. Films-on paper, on glass and also solid material were kept over sulphuric acid in vacuo for twelve days* without bringing about this modification (they were of course thoroughly protected from light). Light is also capable of effecting to some extent this change, as will be described farther on. CopPpER—CoLORED ALLOTROPIC SILVER. The color of allotropie silver depends to a remarkable extent on the amount of washing, which the freshly prepared material receives. With a short washing the material dries to a bright yellow gold color; with more washing to a reddish color ; with still more, the color is a deep rich copper shade. The wash- ing, when conducted in the ordinary manner, is exceedingly troublesome, the material soon begins to run through the filter and blocks it up. This trouble may be completely avoided by washing with a two per cent solution of Rochelle salt instead of pure water, until towards the end of the operation.t * A longer time was inadmissible on account of the tendency to spontaneous alteration. + The mode of preparing the gold and copper colored forms is as follows, the difference is in the length of washing only. In a precipitating jar are placed. Water’. 225: ipa eee eae ee ee ae 800°¢ 20% Sol. Rochelle -salig= teen Me = Sth 7 eee ee 200 40¢@ sol, silver niltdie) = ee ae - Sa 50 In another vessel are placed, Water... (22. Se Se Lt ee 800°¢ 20¢..s0l.. Rochelle salt 228) sese s5-. 2). 24 eee eee ee 200 30% sol. ferrous sulphate (crystallized) _-_..-.---------- 107 (The substances must be added in the order above given and be mixed imme- diately before using. It is scarcely necessary to say that distilled water must be used exclusively.) As soon as the mixtures are made the iron solution is to be poured into the silver and vigorously stirred for some time. The white silver tartrate becomes almost immediately bright red, then deepens in color and finally becomes black. M. C. Lea—Gold-colored Allotropie Silver. ) CaIBE Substances of a character nearly related to those that I have described in this and the previous paper, are obtained by acting on silver tartrate with stannous nitrate. The method is more troublesome and gives inferior results, the gold-colored product is less pure. A beautiful steel-blue substance obtained in this way was found to contain a considerable quantity of tin, probably present as stannic oxide, 10°87 per cent of tin corres- ponding to 13°80 SnO, was found by analysis. Another analy- sis gave 10°66 per cent corresponding to 13°61 SnO,. In the first case the quantity of silver found was 83°61, in the second 84°12 per cent. These results do not lead to any satisfactory formula. The tin is no doubt present as an impurity and as the iron process gave far better results, the examination was not carried farther. Silver citrate gives similar results. ACTION OF DIFFERENT FORMS OF ENERGY ON ALLOTROPIC SILVER. 1. Action of Electricity. High tension electricity instantly converts gold-colored sil- ver to the ordinary form. When paper covered with a film of gold-colored silver is held between the conductors of a Topler- Holtz machine, each spark forms a gray dot of ordinary silver. A powerful discharge is not necessary; an inch spark from a small machine is effectual, even when the condensers are eut off. There is also a lateral action which is best seen when several slips of such paper are held loosely together and placed between the conductors. When the slips are opened a little the lateral branches are beautifully seen, playing through the silver. Their fine emerald-green color contrasts with the purplish shade of the spark. When several pieces are in this way held between the con- ductors together, there is a transfer of silver from one piece to the other, so that the back of each piece of paper is blackened by silver carried over from the one behind it. That the branching gray spots in this way formed, are nor- mal silver, is easily proved by immersing the piece in a dilute solution of potassium ferricyanide. The part acted upon by’ electricity is not affected by the reagent, while the rest of the film shows the coloration characteristic of allotropic silver. In Plate I the upper figure shows a slip of paper, at one end of which electricity has been transmitted, and the figure below, a similar slip that has been subjected to the action of the fer- ricyanide, showing that where electricity has passed the silver has become normal and is not affected by the reagent. 184 M. C. Lea—Gold-colored Allotropic Silver. 2. Action of heat. Allotropic silver is converted by heat to normal silver in either the wet or dry state. Dry heat.—When films of allotropic silver on glass are placed in a water desiccator and are kept at 100 C. for eight or nine hours the central portions are converted into the interme- diate form, while at the edges there is a border of grayish white ordinary silver. In fact the change to white silver at the edge commences before the central part is fully converted to the intermediate form. At higher temperatures the change is much more rapid and better marked. At 180° C. the first effect is to darken a little: (this is usually the first effect of heat) this continues about five minutes. Continuing the heat for ten minutes more the slight darkening disappears and the film has a bright pure gold color sometimes with a slight salmon tinge. The change to the intermediate form is now complete, the film burnishes yellow and does not react with potassium ferricyanide. It is of in- terest to remark that the color reaction persists as long as there is a trace of unconverted material, so that a film may burnish yellow and yet show a well-marked color reaction. This is be- cause most, but not all of the material has undergone conver- sion. At 200° C. the film begins in about ten minutes to show a white border and in half an hour or thereabouts it whitens completely. In these experiments the best support for the film is chemically clean glass) Except that for testing the burnishing a film on paper is needed. The paper should be very pure. Allotropic silver in the solid form heated to 180° or 190° for about fifteen minutes undergoes a similar change: whereas before it was easily pulverized, it is now almost impossible to reduce it to powder and the powder is yellow instead of being grayish black. Moist Heat.—A film spread on pure paper and placed in distilled water maintained at 99° or 100° without actually boil- ing, at the end of half an hour is converted almost wholly to the intermediate form. It burnishes pure yellow but still shows traces of the color reaction. A better plan of operating is to immerse a film spread on glass in distilled water and to place it in a desiccator with a water jacket. After keeping for twenty-four hours close to 100° C. the film has become pure white. It is not disin- tegrated by the change but may be detached from the glass in films exactly resembling ordinary silver leaf. The effects of heat are shown in Plate I, lower pair of figures. M. C. Lea—Gold-colored Allotropice Silver. 185 3. Action of Mechanical Force. (Shearing Stress.) The slightest application of force suffices to instantly convert gold-colored allotropic silver to normal silver. A glass rod with a rounded end drawn lightly over the surface of a film on paper, leaves a white trace behind it. The force sufficient to cause this change is so slight that one might doubt its reality were it not for the decisive proof immediately at hand. First, there is the characteristic change of color: the film is as yellow and as brilliant as gold leaf; the line drawn by the glass rod is of pure white silver. Immersing the film in a solution of potassium ferricyanide the white lines simply change to gold color, whilst the film surface on which they are drawn passes through a brilliant succession of colors. (These effects are represented in Plate II, the uppermost figures.) Jor this use, freshly-made material should be employed, and the film itself should have been freshly spread on pure paper or card and used within a few hours after drying. This because of its easy partial passage, especially in thin films, to the intermedi- ate state, in which it gives a yellow streak. (See also remarks as to partial conversion ante.) When the experiment is performed under proper conditions the effect is very striking by reason of the instant conversion of the pure, deep yellow metal to perfect whiteness without a trace of color. In an earlier communication to this Journal it was mentioned that, having taken with me on a journey several small vials containing gold-colored silver, they were found at the end of the journey to be all converted into white silver without hav- ing undergone any disaggregation, and retaining the original shape of the fragments. The white silver formed had the fine frosted white color of pure silver. This change was attributed to the friction of the fragments against each other, occasioned by the motion of the journey ; a conclusion that was confirmed by finding that when cotton wool was forced into the empty part of the vial in such a way as to prevent all internal move- ment, the substance could be sent over a four-fold distance without alteration. It was also observed (and this is a matter of special interest) that when a partial change had been effected by friction, this alteration went on, although the substance was left perfectly at rest, until it became complete. With time, all solid speci- mens of allotropic silver undergo this spontaneous change to bright white silver, apparently normal silver, even when thoroughly protected from light. Out of over twenty specimens in tightly corked tubes, packed in a box and left in a dark closet for a year, not one 186 M. C. Lea—Gold-colored Allotropic Silver. escaped conversion. Spread on paper or on oe and duly pro- tected, the change is slower. 4, Action of Strong Acids. The action of acids upon allotropic silver has been already described ; it remains only to add here that the conversion to normal silver is entirely unaccompanied by the escape of gase- ous matter; not a bubble can be detected by the closest obser- vation. By acting on dry films with dilute sulphuric acid it is easy to make the conversion gradual and so to trace its passage through the intermediate form. With sulphuric acid diluted with four times its bulk of water and allowed to cool, an immersion of one or two seconds converts a film on glass or on pure paper wholly to the inter- mediate form. It is then bright gold-yellow but shows no color with the ferricyanide reagent. With sulphuric acid diluted with twice its bulk of water and used while still hot, the action is instantaneous and the allotropic silver is converted into light gray normal silver. The silver obtained in this way is very indifferent and gives no reaction with potassium ferri- cyanide, whereas even ordinary silver leaf gives a pale-colored reaction. (See Plate II, lower pair of figures.) The same acid after cooling acts more slowly; the product is more yel- lowish, owing to the presence of a certain quantity of the intermediate form. 5. Aetion of Light. When allotropic silver is spread as a thin film on glass or on pure paper it may be preserved for a length of time apparently unchanged. ‘This appearance is deceptive. From the moment that the film is formed a slow but steady change commences which can be best explained by supposing that a gradual poly- merization takes place. Even after eight or ten hours’ ex- posure to ordinary diffuse light a distinct loss of activity can be detected by careful testing with potassium ferricyanide. The change which occurs is in the nature of a tendency to a very gradual passage into what I have called the intermediate form in which the gold-yellow color remains unchanged while the chemical activity is lost or much diminished. Although a commencement of this change can be detected in a few hours, it goes on very slowly. By exposure to one or two days of summer sunshine (a much longer time is required in winter), the change is nearly complete. The exposed portions are lighter and brighter, and in solution of ferricyanide they color very slowly. M. C. Lea—Gold-colored Allotropie Silver. 187 The question naturally arose whether light by a sufficiently long continued exposure could complete the change and con- vert allotropic to ordinary white silver. ‘T’o obtain a decisive answer the following experiment was made: At a window having a southeastern exposure and unob- structed light there were placed films on glass and on pure paper. Some of these were placed in a printing frame under an opaque design. ‘The others stood side by side with the first but uncovered. The exposure was continued for four months from the end of January to the end of May. At the expira- tion of this time the uncovered paper and glass films were still bright yellow. But of those in the printing frame the exposed portions had become nearly white, while the protected parts retained their full deep gold color. It may at first seem strange that the uncovered pieces were less affected than those exposed in the frame. But this difference was always observed, namely, that if two films were exposed side by side, the one in a print- ing frame under glass, the other simply fastened to a board, the last mentioned was always the less affected. The explana- tion of this seeming anomaly les in the fact that allotropic silver is always much more easily affected by heat than by light. The glass in the printing frame by exposure to sunlight becomes hot to the touch, and thus the film under it is kept at a temperature many degrees higher than that of the other film that is freely exposed to the air; the higher temperature aids. the effect of the light.* It appears, therefore, that the agency of light is somewhat similar to that of the other forms of energy but very much slower. Experiments made for the purpose demonstrated that it is the more refrangible rays that effect the change. With light, the production of the intermediate form is never very satisfactory. Long exposures are needed, and before the change to the intermediate form is complete, the further alter- ation to white seems to commence. With heat the changes are much better marked. When a film on pure paper has received an exposure of one or two days of summer sunshine under an opaque design, the exposed portions are sufficiently changed to have lost much of their chemical activity, so that when the film is plunged into a bath of potassium ferricyanide, the effect given in the lower figure of Plate III is obtained. The color represented is one of an immense variety of tints produced by this reagent on the * Since this was written I find that both Herschel and Hunt noticed an analo- gous fact in the case of silver chloride, viz: that paper prepared with it darkens more rapidly under glass than when freely exposed; without, however, suggest- ing the cause, which is the same in both cases. I have observed that silver chloride darkens more rapidly when exposed under warm water than under cold to the same light in vessels side by side. 188 M. C. Lea—-Gold-colored Allotropic Silver. unaltered or active form. The upper figure of the same plate gives the effect of a very protracted exposure (as above de- scribed) on pure paper (or glass) under glass. With some kinds of sized paper, this effect is produced by a much shorter exposure; apparently owing to the presence of traces of a hyposulphite;* which appears to aid the action of light. These seem to be not merely new facts but to belong to a new class of facts. No instance has been hitherto known of an element existing in so great a variety of forms and passing so readily under the influence of any form of energy from one to another of them. It is evident that a connection must almost certainly exist between these varied transformations and the changes which many silver salts undergo through the action of light and other forces. ‘This connection will form the subject of tie second part of this paper. The present part will be concluded by a somewhat fuller description of the color reaction which is espe- cially characteristic of allotropic silver. THE Couor REACTION. When allotropic silver is immersed in a solution of a sub- stance readily parting with oxygen or sulphur or with a halo- gen, a film is formed which exhibits the colors of thin plates. Such phenomena are familiar and are seen in the blueing or yellowing of steel in tempering and the coloring of other metals when covered with films of oxide or sulphide. With allo- tropic silver the colors are very brilliant, probably because silver is the best of all reflectors for rays having a nearly per- pendicular incidence, sending back about 90 per cent of such. Light gold colored silver gives the most brilliant effects. The substances which produce these reactions are potassium ferricyanide and permanganate, ferric and mercuric chlorides, alkaline hypochlorites and sulphides, mixtures of potassium bichromate with hydrochloric or hydrobromic acid, solution of iodine, ete. : Potassium ferricyanide in a five or ten per cent solution is the best of these reagents because its action is more distinctive. * The behavior of these varieties of paper led me to make inquiries of an intel- ligent paper manufacturer from whom I learned that every sort of paper pulp is now treated with chlorine. As any portion of the bleaching material left in the paper would eventually destroy its strength, it becomes necessary to add hyposulphite in excess to remove it. Accordingly every specimen of sized paper that I have examined contained hyposulphite, even the purest photographic papers were not free from it, though containing greatly less than most others. Apparently, the only difference is that with photographic paper more care is taken to avoid any considerable excess of hyposulphite. M. C. Lea—Gold-colored Allotropie Silver. 189 In particular the blues which it gives are of great purity and the purples very rich. Ferric chloride gives beautiful tints, es- pecially a peculiar glittering rose color. It must be very much diluted, until the solution loses its yellow color and takes a straw shade. It often happens that the characteristic color does not appear whilst the film is in the solution but a bronze shade only, the permanent color appearing only after the film has been dipped into water and blotted off. Potassium per- manganate also gives rise to a beautiful succession of colors on allotropie silver but is somewhat uncertain in its action. A ferricyanide is therefore the best reagent. As to the substance constituting the film which is formed, it is difficult to say whether it is. silver suboxide or ferrocyanide. When potassium ferricyanide is allowed to act on moist allotropic silver suspended in it, and the action of the ferricyanide is carried to its limit, the silver is entirely converted into a yellowish white powder, consisting almost wholly of silver ferrocyanide mixed with a little silver ferricyanide. Of the many varieties of ordinary silver which exist allo- tropic silver is convertible into two only. The high tension spark, heat, and acids convert it to dull gray silver: on this . variety potassium ferricyanide has no action whatever, as will be seen by an inspection of the plates. Light under glass and pressure each convert allotropic to bright white silver, and on this form potassium ferricyanide acts slightly, converting the silver color to gold. It is needless to say that this gold color has nothing to do with allotropic silver: it seems to be pro- duced in the following way. When potassium ferricyanide acts on films of allotropic silver, its first effect is to deepen the gold color to a gold brown, passing rapidly on to other shades. The action on the bright white silver is very slight and apparently just reaches this gold stage, which corresponds to an air film having a thickness of from .0-000150™ to 0:000160™™. The succession of colors obtained on allotropie silver with potassium ferricyanide is as follows: First Order. Russet brown. Brown red. Second Order. Rich and deep purple. Dark blue. Bright blue. Pale blue. ~Green russet. Red. 190 M. C. Lea—Gold-colored Allotropic Silver. Third Order. Reddish purple. Bluish purple. Rich green. The fourth order is not reached, for after this the colors become much mixed, probably the action is no longer sufhi- ciently uniform. The other differences, beside the absence of the fourth order, as will have been observed, are that in place of the yellow of the second order corresponding to a thickness of air of 0:000452™", there is a green though of a more russet shade than that of the third order. In the third order there is at no time a pure blue corres- ponding to 0000602, but only a succession of beautiful red and blue purples, gradually passing into green. There are few more beautiful experiments than to watch these changes. Purity of color, however, depends much on the purity of the paper employed. Want of this purity will often cut short the changes at the pale blue of the second order. I have endeavored to give some idea of these colors in the Plates which accompany this paper, but it has proved to be a most difficult task. The colors represented are, Plate I, purple and blue of the 2d order. Plate II, purple of the 2d order and green of the 3d order. Plate III, brown red of the 1st order. It has not, however, been found possible to correctly repro- duce the brilliancy and depth of color of the originals. Philadelphia, Jan. 24, 1891. (To be continued.) EXPLANATION OF THE PLATES. In each pair of figures the upper one represents the effect of exposing allo- tropic silver to some form of energy. The changes are in all cases similar in character. In the lower of each pair of figures the effect is represented which would be produced by immersing the upper one in a solution of potassium ferricyanide. This affords proof of the completeness of the change by showing that gold-colored silver in passing into the ordinary form has lost its power of reacting with a ferricyanide. In these lower figures an attempt has been made to show some of the colors produced in this way. But they fall far short of the originals in bril- liancy and intensity. These last are so remarkable that the lithographer who executed the work remarked that even an artist with a brush and palette of colors could not imitate them, and that therefore it was hopeless to expect to reproduce them by lithography—in other respects the Plates represent fairly well the changes that take place. J. S. Newberry—Ff lora of the Great Falls Coal Field. 191 Arr. XXI.—The Flora of the Great Falls Coal Field, Montana; by J. 8S. NEWBERRY. (With Plate XIV.) In the School of Mines Quarterly for 1887, I published a brief description of the coal basin which underlies the country about the Great Falls of the Missouri in Montana, and I am now able to add some facts of more than usual geological in- terest to those before known in regard to this coal field. The Great Falls coal basin lies on the north slope of the Belt and Highwood Mountains; the strata all dipping toward the north, These mountains are subordinate folds of the Rocky Mountain system and are each composed of a granitic Archean nucleus, locally overlain by a great thickness of ‘Cambrian rocks which are best seen about Sulphur Springs. This formation must be at least 10,000 feet in thickness, and it underlies the surface from a point fifteen. miles north of Sul- phur Springs to near Townsend on the south. Splendid ex- posures of the same group are seen in Prickly Pear Cafion on the road from Helena to Great Falls. They consist of numerous alternations of thin bands of fine grained sandstone and argillaceous shale, generally metamorphosed into quartzite and slate. Near Sulphur Springs is an outcrop of limestone converted into marble. The prevailing color of the rocks of this group is gray at the surface, darker below. No distinct fossils were found in the slate though particles of carbonaceous matter abound everywhere. A shaly sandstone which appar- ently overlies all the series described is largely made up of Primordial trilobites. On the summit and the north slope of the Belt mountains the Archeean granite nucleus is overlain by Potsdam sandstone full of Scolithus and casts of sea-weeds. ‘There are here nu- merous large dykes of rhyolite which cut the granite and sand- stone. Succeeding the Potsdam sandstone is a great mass of Paleo- zoic limestone, sometimes blue, but mainly of a cream color, which has been cut by the streams draining northward into most picturesque cafions and valleys of which the sides are set with buttes imitating castles, fortresses, churches, ete., combin- ing to form scenery equally attractive to the tourist and geolo- gist. In the limestones are found both Silurian and Carbonif- erous fossils. North of the mountains the limestones are unconformably overlain by a series of sandstones, shales and fresh water limestones which include one large and several smaller seams of coal. These dip toward the north and are soon covered with a great and continuous sheet of glacial drift 192 J. S. Newberry—Ff lora of the Great Falls Coal Field. that for the most part conceals the coal-bearing rocks and ob- scures the extent and outlines of the basin. The Missouri River has cut through the drift and exposed for many miles a series of pinkish sandstones which form the falls. The age of this Great Falls coal basin was for a long time in doubt. Dr. Hayden first visited the locality, but found no fossils, and his experience was repeated by Dr. C. A. White and myself; although the exposures are ample on Sand Coulée and Belt Creek where the main coal has been extensively mined for years. Casts of stems and branches of trees are abundant in the sandstones, and the miners reported the occurrence of impressions of ferns in the shales over the coal, but after the most caretul and thorough search nothing of the kind was found. The coal itself is of fairly good quality, the thicker seam consisting of several benches, of which the lower one, two and a half feet in thickness, makes a very good coke, and the whole will furnish an excellent steam coal for locomotives or stationary engines, will serve well as a household fuel, and is destined to be of great economic importance to the people who shall congregate in this prairie region. Subsequent to my return from Great Falls, Mr. J. J. Hill, the president of the Chicago, St. Paul and Manitoba Railroad, in whose interests | made an examination of the coal basin, sent to me a slab of sandstone covered with Unios. This, as was to be expected, proved the fresh water character of the deposits, but the impressions were too ill defined to permit ac- curate, specific determination, and therefore threw no light upon their age. When the railroad along the north side of the Missouri, constructed with such unexampled rapidity by Mr. Hill, reached Great Falls, a cutting near the town passed through shales in which were numerous lenticular nodules of iron ore. Each of these contained a fern frond, a cycad leaf or a twig of aconifer. Some of them were collected by Mr. R. S. Williams of Great Falls, by whom they were sent to Pro- fessor Dana at New Haven. He submitted them to me for ex- amination and I found that without exception they were species that had been described by Sir William Dawson from his Kootanie group [Lower Cretaceous] of Canada, or by Professor Heer trom the Kome group of Greenland. These included Sequoia Smittiana Heer; S. gracilis Heer; Zamites acuti- penmis Heer; Z. Montana Dawson, etc. More recently Mr. Williams has sent to me a larger collection of fossil plants con- sisting mostly of ferns, from a different stratum in the Great Falls group. On opening the box I thought I identified a number of these with species described by Professor W. M. Fontaine from the Potomac group in Maryland and Virginia. But that there might be no mistake on a subject of such geo- J. 8. Newberry—Fflora of the Great Falls Coal Field. 198 logical importance, I forwarded specimens of each species to Professor Fontaine asking that he would compare them with his Potomae fossils and decide upon their identity or difference. His letter in reply is so interesting that I herewith append a copy of it. University oF Virernia, Oct. 15, 1890. Dr. J. 5. NEwBErRY— Dear Sir:—I have examined the plant fossils that you ob- tained from Great Falls, Montana, and sent to me for comparison with the fossils of the Potomac formation. I find them to be as follows: . Thyrsopteris rarinervis ¥. . A plant near to Podozamites distantinervis F. . Cladophlebis parva F. . Sequoia Reichenbachi H. Pecopteris Browniana F. Aspidium Fredericksburgense F. . Sphenolepidium Virginicum ¥. . A plant allied to Zhyrsopteris brevifolia F. . A plant near to Cladophlebis distans F. 10. Thyrsopteris insignis F. ll. Carpolithus Virginiensis F. 12. A plant near to Uycadiospermum rotundatum F. 13. Pecopteris microdonta F. | 14, Thyrsopteris brevipennis ¥. 15. A plant near Cladophlebis constricta F. The above named identities and resemblances are found on comparing the plants sent, with fossils of the Potomac formation described in Monograph XV of the publications of the U.S. Ge- ological Survey. The forms that I enumerate as “‘ near” to named Potomac fos- sils, I hesitate to identify with them on account of the small amount or poor preservation of the material in hand available for comparison. | It should be stated that No. 9, which in foliage shows a facies like Cladophlebis distans has a fructification lke that of some Aspidia and if identical with the Potomac plant this fact wonld remove it from the genus Cladophiebis. © Yours truly, W. M. Fontaine. OamTIHS or WD The above identifications prove conclusively the general identity of the geological horizons of the Potomac group, the Great Falls group, the Kootanie group of Canada and the Kome group of Greenland, and confirm the view advocated by Professor Fontaine and myself that the Potomac group is Lower Cretaceous and not Jurassic. Professor L. F. Ward in his review of the Potomac flora, (this Journal,) leaves the question of the age of the Potomac 194 JS. Newberry—F lora of the Great Falls Coal Field. group in doubt, but his opinion seems rather to incline toa Jurassic date. Professor O. C. Marsh considers the Potomac group Upper Jurassic, because he has obtained from it a num- ber of reptilian remains of decided Jurassic affinities, but he tells me there are no species which he can identify with those of the Jurassic system, and we have been hitherto with little or no information about the vertebrate fauna of the Lower Cretaceous rocks of North America; so we need not be sur- prised to find it exhibiting marked Jurassic affinities. As pointed out by Professor Marsh the low grade and Mesozoic character of the mammalian fauna of the upper member of the Cretaceous system, the Laramie, would without other evidence lead to the conclusion that it was much older than it really is. Professor Fontaine makes the Potomac group about the geo- logical equivalent of the Wealden of Europe, but for the rea- son that it contains eighty known species of angiosperms out of a total number of three hundred and seventy-five, I am in- clined to regard it as newer rather than older than the Weal- den. The fossil plants of the Jurassic have been collected in large numbers and in many countries, but nowhere has a dico- tyledonous plant been found in that formation, nor has an an- giosperm been discovered in the Wealden of England or on the continent of Europe. The plants of the Wealden have been fully described by Dunker, Schenk and others, but all the species known are cycads, conifers or ferns. I recently had an opportunity, through the kindness of M. Dollo, of examining the plants found with the Iguanodons at bernissart, and among them all there was not a trace of an angiosperm. This does not absolutely prove that the Potomac group is of more modern date than the Wealden, because the progress of plant life has been, as we know, somewhat unlike in different parts of the world, and the angiosperms may have begun their existence on the North American continent sooner than elsewhere, but it seems hardly possible that eighty or more species of arborescent angiosperms should have flourished on this continent before they had put in an appearance in the vegetation of the Old World. We may at least say that Professor Fontaine is fully justified in his conclusion that the Potomac is not older than the Wealden. The relations of the Potomac to the Amboy flora are of special interest; the two formations are consecutive members of the Cretaceous system and the “variegated marls” of Fon- taine or the “alternate sands and clays” of Uhler may be regarded as the southern extension of the Amboy clay group. Yet a long interval of time must have separated the epochs of the two formations, since the floras are so entirely different. Only a beginning has yet been made in the exploration of the J. S. Newberry—Fflora of the Great Falls Coal Field. 195 flora of the Amboy clays and yet we have obtained from them more than one hundred and fifty species. Probably when as much time shall have been given to the collection of plants from the Amboy clays as has been devoted to the collection of Potomac plants, the number of species will be as large, and better comparisons can then be made between the two floras, but it is evident that they are widely different. [Irom the Amboy clays we have now taken about one hundred and fifty species of plants; of these more than one hundred, or a large majority, are angiosperms, whereas of three hundred and sev- enty-five species taken from the Potomac group only eighty are dicotyledonous. Besides this, it is doubtful whether any species yet found is common to the two formations. The flora of the Amboy clays is most nearly allied to that of the Dakota group in the far west. and the Atane group of Greenland, while one or two species are apparently identical with some taken from the Kome or Lower Cretaceous group. We may therefore fix the horizon of the Amboy clays with absolute certainty at Middle Cretaceous. With equal certainty we can assert that the Potomac, the Kootanie and the Kome groups represent perhaps distinct but closely related epochs of the Neocomian or Lower Cretaceous of the Old World. As these determinations have for the most part been made from fossil plants, we must wait for the discovery of plants in the Cretaceous beds of Queen Charlotte’s Island and the Shasta group of California before we can accurately correlate them with the Lower Cretaceous strata of Central North America. For this region the history of the Cretaceous age can already be written with a good degree of fullness and its more impor- tant incidents are as follows. During the first half of the Cretaceous age the greater part of the continent of North America was out of water and there- fore suffering erosion and receiving no deposition. During this interval a broad, circumscribed and almost inland sea oceu- pied the place of the Gulf of Mexico, and the adjoining shores of South America, Mexico and Texas. In this sea marine depos- its were forming which are the equivalents of the Lower Greensand or Neocomian. In time they attained in Chihuahua a thickness of not less than 4,000 feet and represent at least one-half of the Cretaceous age. During this time the area of the plains was out of water and toward the north bore on its surface lakes and marshes where the Great Falls and Kootanie groups were deposited. Beds of coal of considerable thick- ness and now of great importance were formed in these marshes. Up to the present time we have gathered thirty or forty species of the plants which from their debris formed the Am. Jour. Scr.—Tuirp SERIES, Vou. XLI, No. 243.—Marcg, 1891. 196 J. S&S. Newberry—flora of the Great Falls Coal Field. peat that has now become coal. So far we have found among the remains of these plants not a single dicotyledonous leaf, but judging from the flora of the Potomac group and that of the Kome beds which have so many species in common with the Kootanie and Great Falls deposits, we may expect in the future to find a few angiosperms, the remains of the pioneers and advanced guard of the great army which here mingled with the cycads and conifers, and soon, through some inseruta- ble influence, mostly superseded them. After the Kootanie epoch the eastern half of the N meen American continent was depressed and the sea gradually rose upon it, moving inwards, spreading a sheet of sea beach as far as it extended [the Dakota sandstone] and ultimately covering with 2,000 feet or more of marine sediments [the Colorado or oup] all the great depressed area lying between the Cumber- land and Canadian highlands and the Wasatch. The third great period of the Cretaceous age was the gradual emergence of this portion of the continent from the sea and the formation of the Laramie group with its great series of -eoal beds, its abundant land flora and its horned Dinosaurs. This closes the history of the Cretaceous age in North America. | The record which we have of the plant life of the continent during this long and varied interval is of special interest be- cause we can reproduce the topography of the continent and in imagination clothe all its highlands with the successive phases of vegetation which we have disinterred in such abun- dance from the lacustrine and estuary deposits of its different epochs. The first Cretaceous forests were composed chiefly of cycads and conifers, showing great variety, because this was a part of their eolden age. “With these were numerous ferns more nearly allied to those of the present day than those of the Trias or Jura, several of the genera, as Gleechenia, Asple- nium and Aspidium, continuing to the present day. This was the Kootanie epoch or that of the Great Falls coal basin, perhaps synchronous with, but more likely a little anterior to the Potomac epoch, in as much as we have found no angio- sperms in the Kootanie flora. Then came the Potomac group with a wonderful variety of conifers and cycads and with about one-fourth of its species angiosperms. Later still the epoch of the Amboy clays and Dakota sandstones when two-thirds to three-fourths of the species were angiosperms, but no palms had yet appeared. Finally came the Laramie epoch, when the cycads and coni- fers constituted not more than one-tenth of the flora and the botanical aspects of the vegetation were essentially those of to- day, only palms were numerous as far north as the Canadian line, and the temperature was a little higher than at present. J. S. Newberry—f lora of the Great Falls Coal Field. 197% List of Potomac species occurring elsewhere. Equisetum Lyelli Mant., Wealden, Germany. Pecopteris socialis*? Heer, Atane, Greenland. Pecopteris Browniana Dunk., Wealden, Germany. Sphenopteris Mantelli Brongn., Wealden, Germany. Aspidium Oerstedi*? Heer, Atane, Greenland. Aspidium Dunkert Schimp., Wealden, Germany. Gleichenia Nordenskioldi Heer, Kome, Greenland. Dioonites Buchianus Schimp., Wealden, Germany. Sequoia Reichenbachi Heer, Cretaceous [ general ]. Sequoia subulata Heer, Kome, Greenland. Sequoia ambigua Heer, Kome, Greenland. Sequoia rigida Heer, Kome, Greenland. Sphenolepidium Kurrianum Heer, Wealden, Germany. Sphenolepidium Sternbergianum Heer, Wealden, Germany. Potomac Plants in Great Falls Group. Sphenolepidium Virginicum FP. Carpolithus Virginiensis F. Thyrsopteris rarinervis F. Aspidium Fredericksburgense F. Thyrsopteris insignis FP. Thyrsopteris brevipennis F. Sequoia Reichenbachi Heer. Pecopteris Browniana Dunk. Cladophlebis distans ¥. Pecopteris microdonta F. Thyrsopteris brevifolia FB, Cladophlebis parva F. Cladophlebis constricta F. Great Falls Plants in Kootanie Group, Canada. Sequoia Smittiana Heer. Zamites Montana Dawson. Zamites acutipennis, Heer. Great Falls Plants in Kome Group, Greenland. Sequoia Smittiana Heer. Oleandra arctica Heer. Zamites acutipennis Heer. Zamites borealis Heer. Sequoia Keichenbachi Heer. Sequoia gracilis Heer. * The materials on which Prof. Fontaine based the identification of these spe- cies are insufficient for satisfactory comparison; and while it is not impossible that the life of one or more species may have stretched over all the interval be- tween the beginning and end of the Cretaceous age, stronger evidence of this fact than any we yet have must be furnished before we can consider it as established. 198 SJ. 8. Newberry—Ff lora of the Great Falls Coal Field. Since the above notes were written I have received, through the kindness of Mr. Williams, another collection of fossil plants from Great Falls. With several species before mentioned, it includes some which seem to be new, and of which brief de- scriptions are given below. Chiropteris Williamsii, un. sp. PIA, as Os aT Fronds orbicular, oblong or lobed, two to four inches in diam- eter; petiolate, margins entire, nervation radiate, dichotomously forked and somewhat reticulated. Of this remarkable fern I have many specimens, but none quite complete. At first sight they suggest the fronds of Doleropteris of the Coal Measures, but in that genus the nerves are fasciculate and divide by separation of the bundles and not by forking, and they never anastomose. In some specimens of the plant before us the nerves are buried in the parenchyma, showing that the con- sistence was thick and leathery; in others, perhaps more macer- ated, the nerves appear very distinct and rather coarse. A single small specimen shows a distinct stipe at the base. This plant I have included in the genus Chiropteris with much hesitation, for it differs from the type species in having an orbicu- lar or elliptical frond which is generally simple, though some- times lobed, while in C. Kurriana, the type, the frond is flabel- late and deeply lobed, almost palmate, thus approaching Sagenop- teris, but in that genus the frond is distinctly palmate, the divis- ions being lanceolate, though springing from a common base. The nervation too of Sagenopteris is much more closely reticu- lated. In these respects the two genera would seem to be distinct. The nervation of our plant is essentially that of Chiropteris, the nerve branches anastomosing only at rare intervals, the meshes being many times longer than broad. In the original notice of Chiropteris, by Dr. H. G. Bronn (Jahr- buch fiir Mineralogie, 1858), the fronds are represented as radiat- ing in a whorl from a common base, and the nerves are neither figured nor described as inosculating, but Schimper in his Pale- ontologie Vegetale, (Vol. I, p. 643, Pl]. XLII) describes and fig- ures the frond of C. Kurriana, as flabellate, digitately-incised, the nerves frequently forked and anastomosing to form narrow meshes. This description corresponds closely with some speci- mens of our plant, and while it is specifically distinct I do not feel justified, without more material, in separating it from the genus Chiropteris. Possibly facts will hereafter come to light which will require this to be set apart as the type of a new genus. The horizon of the type specimen of Chiropteris is the upper Trias or Rhaetic. In the Jurassic rocks the genus has not been recognized, but its place has been taken by the allied Sagenopteris. Prof. Fontaine, in Monograph XV, U. 8. Geological Survey, de- scribes several species of Sagenopteris, but in these the form was very different and the nervation much more closely reticulated. J. 8. Newberry—Ff lora of the Great Falls Coal Field. 199 Formation and locality, Kootanie group, Great Falls, Montana. Collected by Mr. R. 8. Williams and dedicated to him. Chiropteris spatulata, n. sp. Pl. XIV, figs. 1, 2. Pinnules 14-2 inches long, spatulate in outline, midrib strong, lateral nerves well defined, coarsely reticulated. The plants to which I have given the above name have precisely the nervation of the large rounded or lobate leaves, figured on the same plate and named Chiropteris Williamsii; and I have there- fore provisionally placed them together. The form of both spe- cies is so different from that of the typical Chiropteris, that I have included them in that genus with much hesitation. The nervation is however so peculiar and so much alike in these two ferns, that while waiting for more material that shall permit a new genus to be defined upon them, I have concluded to group them together and under the old name. Formation and locality, Kootanie group, Great Falls, Montana. Collected by Mr. R. 8S. Williams. Zamites apertus, n. sp. Pl. XIV, fig. 4, 5. Fronds several inches in length by about one inch in width, pinnules leaving the rachis at nearly a right angle, linear, obtuse, somewhat widely separated; nerves invisible, sunk in the paren- chyma. This is a small species having the general aspect of Zamites arctica, Gepp (Flora Arctica, vol. ili, p. 67, Pl. XV, figs. 1, 2), but is much more open in structure, the pinnules being separated by spaces sometimes as wide as themselves. Formation and locality, Kootanie group, Great Falls of the Missouri, Montana. Collected by R. 8. Williams. Baiera brevifolia, nu. sp. Pl. XIV, fig. 3. Leaves flabellate, long petioled, one inch in width by one-half to three-quarters of an inch in length, deeply lobed; lobes trun- cate, sometimes undulate and slightly contracted at the summit. This species has much the aspect of B. pluripartita, Schimper (Paleontologie vegetale, vol. i, p. 4238, Pl. XXXI, fig. 12,) (Schenk, Flora Nordwestdeutschen Wealdenformation, p. 10, Pl. III, figs. 1-8), but is much smaller. Possibly, however, it is merely a depauperate form or smaller variety. of that species. Further material will be required for deciding this question. _ However, the specimens which we have are not half the size of those figured by Schimper, Schenk, Dunker and Brongniart. The specimens of Bb. pluripartita (Cyclopteris digitata, Dunker) are all from the Wealden of different localities in Europe. 200 J. S. Newberry—Fflora of the Great Falls Coal Field. - Formation and locality, Kootanie group, Great Falls of the Missouri, Montana. Collected by R. 8. Williams. Cladophlebis angustifolia, n. sp. PL XT, ao. 8: Pinne several inches in length by one inch in maximum width; pinnules ten to twelve mm. in length by three mm. in width at base, distinctly separated, attached to the entire base, curved or falcate in form, subacute or obtuse at summit; nervation open, strong. This plant resembles C. falcata Fontaine (Monog. XV, p. 72, Pl. V, figs. 1-6), but the pinnules are smaller, narrower and less acute. . Formation and locality, Kootanie group, Great Falls of the Missouri, Montana. Collected by R. 8S. Williams. Sequoia ucutifolia, n. sp. Pl; XPV ie. 1, da: Leaves crowded, from one-quarter to one-half an inch in length, wedge-shaped, rounded or abruptly contracted at the base, sum- mit long pointed, very acute. Only one twig of this tree is contained in the collection, but its leaves are so peculiar that I feel quite justified in considering it a new species. Its most striking feature is the wedge-shaped outline of the leaves which are broadest near the base and are drawn out in a long and very acute point. In the Cretaceous rocks of Vancouver’s Island occur twigs of a species of Sequoia to which I have given the name of Sequoia cuneata because they are so decidedly wedge-shaped, but in that species the leaves are spatulate, broadest near the rounded summit and terminate below in a wedge-shaped base. In the species now under consideration the leaves have quite an opposite form; being broadest at or near the base and terminating above in a long drawn acute point. Among all the living and fossil species of Seguoia there is no other known to me that has leaves of this peculiar form. Formation and locality, Kootanie group, Great Falls, Montana. Collected by Mr. R. 8. Williams. Podozamites nervosa, 0. sp. PLOT, fe), Leaflets, four inches in length, lanceolate, broadest toward the base, subacute at the summit; nerves parallel, distant, strong. This is a leaflet of a frond of a strong-growing species of zamites similar to Heer’s B. marginatus, but differing from that in its much more remote parallel and distinct nerves. Only one speci- men has been as yet received from Mr. Williams, and more will be needed before we can define the range of variation in the pinnules. Spencer—High Level Shores of the Great Lakes, etc. 201 Oleandra arctica Heer. 121 OOD ities, ©). The specimen figured agrees in all essential characters with Heer’s plant from the Kome group, Greenland, described in vol. iii of his Flora Arctica. A much larger and finer specimen has been sent to me by Mr. Williams, but the figure now given will permit the identification of the plant wherever found. This is interesting as another connecting link between the flora of the Great Falls group, and that of the Lower Cretaceous of Green- land. Art. XXIL.—Migh Level Shores in the region of the Great Lakes, and their Deformation ; by J. W. SPENCER. CERTAIN of the deserted shores about the Great Lakes have been already described in the author’s papers on the Iroquois and Algonquin Beaches.* The Iroquois Beach is confined to the Ontario basin, and the Algonquin Beach still defines the deserted shores of the lake which embraced Georgian Bay and Lakes Huron, Michigan and Superior during the episode when they formed one expanded sheet of water. But above these beaches there are others not confined to any of the exist- ing basins, but at elevations which required all of the lakes to have been united into one sheet of water. This sheet, whose dimensions have only in part been surveyed, | named Warren Water.t As the southern and southwestern shores have been surveyed for a length of eight or nine hundred miles, and several hundred miles of the coast line about the former large island, now represented by a part of the Province of Ontario, are known, the work seems to justify this publication without further delay (see map, p. 202). In the investigation of the high beaches, I acknowledge with great pleasure the assistance of Prof. W. W. Clendenin and Prof. W. J. Spilman, who accompanied me in the re- searches. Respecting the beaches upon the Canadian side of the lake, no other systematic exploration has been made. Four or five years ago, some of our friends put ice dams, where beaches are well developed, to hold up the waters whose waves built up the beaches upon the southern side of Lake Erie. In Michigan, the record was nearly as meagre, although * The Iroquois Beach: A chapter in the Geological History of Lake Ontario. Trans. Roy. Soc. Can., p. 121, 1889. Deformation of the Iroquois Beach and Birth of Lake Ontario. This Journal, vol. xl, p. 443, 1890, Deformation of the Algonquin Beach and Birth of Lake Huron. Ibid., vol. xli, p. 12, 1891. + See Notice of Iroquois Beach, Science, vol. xi, p. 49, Jan. 27, 1888. gh Level Shores of the Z Spencer—H + . J. W 202 re OS 16g 0} snotdotd oprut sXoains Aq pojooutoonn SOL JO UOIVI0] MOYS SJOq ‘suonIsod oyemixoidde Ay) Wuasotdod Sout] UoxO1g , *[OAo[-vas ovoqu Soyovog poWMAsojac[ ot JO SuONero][o OF Aojoa deyy mo sons] oe ‘UHONAMS “M ‘f ag PUBjeAe} 10% SaHVT LVAYD FHL LAOGV ae ) I uoryt pgs S Sayoveg podju9seq JO UuOI}ISOg A ONIMOHS dV ae Le : y A oy ' e L00ze PF eee EES (629) o/ ques es opzeweley / is % ; samquey| bgt) UEPMONS, : Sag ; yas 3 ee Di 7 pIauaC ae: te aes BIquin}oy/4a19 my OP S opelingt sy nee HOR: fe1Z, ‘e¥9, N ts UIPUINAD og mf es i com bg E i SS seca Q hie ee = oe — _— Z Bre Ne er 019° spid ued ame ».,,, SOM POOL... Be ie & yma jp vu Bye) ‘ ee oe 706 ‘ se o 4 DuYD U1 | & \ plo LUC Mobis? 168) (é Fost i Sy" ws ae ay 086; Y, ay \ oe Driesvies Le el xt /OOvl . i \ \, : Eves ee LO ee 0691, 686%, 4, & x nN) Shy 4 1 OGe SCUIO cng a iN) : coo a fey =) aw vag . =aet a Qt Ke ihe OEb! = is . “on Is na ett Se eget, ay 6 AQ .4I)| ay Val: : ro A) So a Gee ear eee oe ete OR aie Be oe BM S = iF) esenaee — Great Lakes, and their Deformation. 203 some of the beaches had been used as roads since the days of Indian habitation. But in Ohio, more or less work had been done, which will be referred to in its proper place. Upon both sides of the St. Clair River, a succession of beaches may be seen, in ascending inland over the slowly rising plains. The beaches are of the same character as those described in the author’s earlier papers upon ancient shores. But they appear to represent a rather shorter time in formation than the Troquois and Algonquin Beaches. THE Forest BeacH.—Upon the Canadian side of the St. Clair River, the first important deserted shore line, above the Algonquin "Beach, may be seen at Forest—and hence I will name it the Forest Beach. This has been explored in both directions from Forest, as shown on the map, with elevations as in the table—these being instrumentally levelled. Feet above the Sea. Pakcmbtnir nvm yes ones cesta er, ht 582 1 OE REIS Spey 2 et aa So A Ee ue ee a eee 720 WastOrlbacwhithy es tus Aer 2 eo eal 2 736 Ne aaa yinCl@un seme hase eee fd. 767 Rolph oon po wen iniee Je 08 Fi a eae 813 Walkerton ‘(terrace in valley) .---------.-.-. 825 Paisley, (terrace. inivalley):.~ 22... 2...2 5) 72-- 860 BasiOteDuLcoOyne 22552602 22s 18 is 22h ees 876 Rockford (spit across. valley) ..-.---..=.-22-+- 915 Barrie (on insular ridge) ---- -- Eid eee ee =e 910 East of Rockford the country is not favorable for the identi- fication of the old beaches, as they were interrupted by the promontory of Blue Mountains extending into the former sheet of water, but on it various rock-terrace shore-lines are engraved. On the drift hills farther eastward, ridges reappear at elevations above the Algonquin Beach, which would point to their identification with the Forest Beach. In this north- eastward direction our survey was discontinued. From Forest, the beach has been explored, upon the northern side of Lake Erie, and the equivalent terraces traced to north of Lake Ontario. The measured elevation at various points are ; Feet above the Sea. Komoko (tegracemevalley), 2. 2. 22 2222 - hee White’s Station (south of London).--.--- ---- 715 Nese? Wiaterionds warn seieanee eh OS. cue 77 ran bhOudss 24 = gs wee et oe ea a peta a 805 Pushlinch Church (rock-terrace) .----------- 840 Genre ectowmn (terrae) aes ic. n) ih een 891 Mono Road (bGEraee peer lass fe eos 930 Northof Stoufiville (terrace)... -. 2222252- 1025 204 J. W. Spencer—High Level Shores of the The terrace is a strong topographical feature, especially after passing over the Niagara escarpment near Georgetown. The differential elevation of the Forest Beach, in the extreme southwestern part of the Province of Ontario, is 1-44 feet per mile in a direction of N. 28° E. But northeast of Toronto this warping has increased to three feet per mile as it trends north of east, with the direction of the maximum rise not deter- mined. This warping is in harmony with the deformation of the Iroquois Beach, in the same region, being only slightly in excess, as it should be. No attempt has been made to explore the extreme eastern and northern portions of the Forest Beach, around the island of the Province of Ontario. THe ArKoNA BEeAcH.—This beach is less perfect than the Forest Beach. It is prominent at Arkona, rises to 789 feet east of Ailsa Craig, passes by Varna and Ripley, and near Walkerton has an elevation of 944 feet. At Chatsworth, the spit across the valley at 985 feet, probably belongs to this shore-line. No further explorations have been made in this direction. Southwest of Arkona, the beach has an elevation of 773 feet at Waterford; 754, on a river terrace near Komoko ; 735 (?) at Taylor; 776, on the plains at St. Thomas; 792 at Cornith ; 804 at Delhi. Beyond this point there are shore remains, at 903 feet near Paris; a terrace at Limehouse, at 970, and at Stouffville, a gravel ridge skirting higher land, at 1175 feet. These latter fragments may be the equivalents of the Arkona Beach. But these last named shore-lines continue the upward succession of deserted water-lines even if not iden- tical with the Arkona Beach. This beach is imperfectly ex- plored, and is more or less interrupted, like other shore-lines, in the lake region as well as those nearer the sea coast, such as on Mt. Desert Island. RipGEWAY AND HicHER BracHEs.—Above the Arkona beach, the next shore-line is here named the Ridgeway Beach, (as this is a suitable name for its counterpart in Michigan). Its elevation, near the following places, is: Feet above the Sea. KK Om OKO 2 oe ete ae rs A er ee Lucan Junctowme ees. eee ee ees 891 Hlengall 5 2 eee tt ay oe 2 ea Oren 925 Ge ee ee ee eine oe Ao ee a 989 As the object of our surveys was for the more especial exploration of the lower beaches, the explorations were not carried throughout the distribution of the higher beaches. But beaches, spits across valleys, and terraces carved out of the Niagara escarpment were seen in many places at altitudes which would correspond to the continuation of this shore-line. Back and above this beach, there is a belt of flat plains, corres- Great Lakes, and their Deformation. 205 ponding to the frontal plains of still higher deserted coast-lines. Indeed, in the fragments seen, several other still high coast- lines are recorded. The altitudes of several of these are here given, and those marked with an asterisk are in topographical positions that would permit of their identity with the Ridge- way Beach, which has not however been continuously traced between all the points. Feet above the Sea. Seven miles south of London=. 22/2 _22. 2... * 882 6¢ c¢ ce TOG, Or a ec a 872 6¢ Ce ie hale i eal hectare? eee 862 Near inioencolleme ee ete ee ea rs is eo *994 (Nk ee rc nanyatt ce cs ie pea Mecho ka Gites “ (terrace) ae ee ees O09 Corwhin (rock-cut terrace with gravel floor)*1127 Acton (rock-cut terrace with gravel floor) -.*1160 Near Mono Mills (rock-terrace) --------.--- 1400 (bar.) 6 es (oravel@ terrace) s 425 2. 1375 (bar.) e ef (terrace) Sav ren a2) 22211200) bar) West of Collingwood (rock-terrace) -..---- 1400 (bar.) Wiest of Clarksbure: (beach) 2225.5 22: 2-5 - 1396 oe (beaeh ies 5 yee fe. Ady eye re (nock-terrace)= 2: =: 1262 66 66 ce taal ie ee a 1225 Duneans(roek-terkace). =) 2.5 442. 2. 2 1260 (bar) N. E. of Flesherton (terrace with gravel SUI@YOIRS) eS NE OO eh eee a 1430 (bar.) bya cee ee ee ee ee 1690 ReEOLOrIN (IO AMS) fee Oye a a 1613 Southvot Markdale: (terrace). 2-2 222 2 82 252 1425 (bar.) ot EMC Yc bed OU amie es 1400 (bar.) Markdale Station (terrace) 2. ..-.2.._.2_- 1360 2 miles north of Berkley (gravel spit)....-- 1260 (bar.) PAM OG Es MUCRRACE paper hs Mer ash 1067 The beach remnant, in the region of Dundalk, is only twenty feet below the highest point of land, which once formed a small island. From this point down to sea-level, there is abundant proof, i the beaches, spits, sea-cliffs, and cut terraces that there was a long succession of intermittent episodes of subsiding waters from the highest lands of the peninsula of Ontario—lands often higher than the highlands north of the Great Lakes, which now constitute the Laurentian Mountains —care having been taken to distinguish these named structures from those gravel deposits belonging to the older drift episodes. Even after allowing for the amount of more recent terrestrial warping, these higher shores of Ontario rise far above much of the land to the south of the lakes. All of the deserted water- margins are more recent than the drift deposits, and some 206 J. W. Spencer High Level Shores of the of them are cut out of the third series of till, which covers ridges and plains of much of the highlands of Ontario. The highlands of the peninsula then rose up as a growing island out of the receding Warren Water. The position and relative heights of the beaches of the two sides of the St. Clair River are seen in the following section, aumee ee a te Z i EE Pee 5 : L£orest Bea which represents a profile across them along a nearly east and west line. Making allowance for the terrestrial deformation between the beaches themselves, it will be readily seen that there is only a slightly greater amount of rise between mem- bers of the series upon the eastern side than upon the western, and this is in harmony with all the observations else- where about the lakes. Hence, I have been forced to accept the identity of the two sets on the opposite sides of the St. Clair River, as there are no important intervening shore-mark- ings, on the plains between the named ridges, although those upon the western side are more sandy than on the eastern. THE Forest Beacd skirts the plains at the head of Saginaw Bay and passes around the thumb of Michigan. About five miles west of Feet above the Sea. _ Port Huron, it is duny with an elevation of__ 665 HaAgE [OP perv ille 2 oat. ae ee 668 Dy bya men 0 Seok ss a Meese ee eee 663 Hast of Defiance (Gilbert) _...---.-------- 653 Cleveland oll o Sen Ueno aa eee 673 (bar.) Madison 222227 Seis ee ae ee 680 Sheridan Centre, N. Y., (Gilbert) .--.---~- 773 Crittenden, N.. Yo: (Gallbert)o. =, 4). ieee: 860 THE ARKONA BEACH has an elevation of—near Goodall. 402 ees eas Ged She ee 697 Denton 2.31 eee eee Pee See 694 Blissfield (ridgevdunw); 2259422. us. eS 694 Cleveland: #8 ae wea se aie ees 708 A record of this shore-line is more meagre than the last. Both of these beaches have been more or less surveyed in Ohio by the late Geological Survey of that State,* and Mr. G. K. Gilbert has measured the continuation of the lower for some distance beyond the State line, mto New York. The Lower, * Geology of Ohio, vol. i, map, p. 549. Great Lakes, and their Deformation. 207 or Forest Beach, is identical with that numbered four of the Ohio Survey, at the head of Lake Erie. Spits and spurs are frequently given off from these beaches, and add some difficulty to the surveying, especially in Ohio. THe RipGeway BeEAcH, or next highest shore-line, is the most important of the whole series, as it has been explored for the greatest distance, and is perhaps the easiest of identifica- tion. On it, many long stretches of dry roads, bounded by muddy plains, have been used from the first settlement of the country. The other ridges have also in places been used for roads, but to a less extent. Elevations on the Ridgeway Beach determined by Leveling. Feet above the Sea. Lake Michigan and Lake Huron..----.---- 582 LUEIRG) DING Wael Ss sR Res Cee tee eee 573 Beach near Chicago (calculated) -- ---- 526-542 eam Colum bias Mrchs 498 <6 2 sco? 8) 618 (bar.) fulecany(terrace)mine valley, 22 29.5.2. f2 2 643 Grams apids ss osteo s Ee 620 EeaeMITROMES See een hs ee ee 724 CO Fioip iif ee a eke ek 760 (bar.) sO MMe tge = ene 2 ee eS et Soh 770 Meas envilless semen fy Oa ees rs 753 Basizone psilantin ese r. iyece soe bs Pel tod West of Lenawee Junction __-.-._---.--.--- 735 WerancepOMiome sees wee NN oe So OSS 738 (Gilbert.) @leveland! 722322. Regn ie ape ve Ate tS 743 (Geol. Ohio.) Ereliso mnt ae eee a Pye SS 2 2 740 (bar.) Sitemd@am Cente tN PV tes oe Sees tl os 834 (Gilbert.) Biernluine ces Ge eke Sit eee ee 870(+ or —20) (Gilbert.) Throughout the windings, this coast line has been explored for eight or nine hundred miles. The highest beach south of Chicago is only 42 feet above the lake, and this probably belongs to a series to be noted hereafter, and from it the position of the Ridgeway Beach is calculated. The country southeast of Lake Michigan is very sandy and duny, and thus it is more difficult to recognize the exact water-margins than farther east where the beaches are narrow ridges between clay plains. From Grand Rapids to Pewamo the beach passes through a strait between high lands on both sides. This depression is now occupied by the Grand River, between the head waters of which, and those draining into Saginaw Bay, the divide does not exceed a height of one hundred feet above the lakes, although the land rises many hundred feet on both sides, Indeed, from even west of Pewamo the low embayment widens 208 J, W. Spencer— High Level Shores of the and forms the broad flat plains at the head of Saginaw Bay. But these plains, for half their length, are drained to the west by the Grand River, although they were formerly the floor of the lately enlarged Saginaw Bay. Hence, the topography shows the reversal of the drainage, by a slight uplift towards the east and north, which in the region of Pewamo amounts to about a foot per mile. This rise continues to Chapin, whence the beach rises towards the northeast and passes around the thumb of Michigan, and descends to about a mile east of Emmett. From the crossing of the beach, east of Ypsilanti, to Lenawee, there is no terrestrial warping as shown by instrumental measurements. The occurrence of this beach, although not identified throughout any distance, was described by Prof. A. Winchell.* From Lenawee, the Ridgeway Beach extends into Ohio, and becomes identical with the beach of the Maumee Valley, called by Mr. Gilbert number three.t Thence it extends eastward with natural interruptions. From Ohio ‘it has been traced into New York by Mr. Gilbert. The portion south of the western half of the lake practically shows no deformation, but between Madison and Sheridan Centre, it rises about a foot per mile, while the lower, or Forest Beach rises in the same distance only about three quarters of a foot, although eastward of that point the last named beach rises two feet per mile. : At the head of the Maumee valley, a fragment of a beach, about thirty feet higher than the Ridgeway Beach, was de- seribed in the Geology of Ohio.t This, however, is only occa- sionally met with. A beach at Grand Rapids, Mich., at 700 feet, and a terrace near Allegan at 689, may be the equivalent of that in Ohio. THE Maumee Beacu.—This is the next highest of the well defined beaches’ which have been studied. That, at 42 feet above the lake at Chicago, is probably identical with the beach, which has been traced from the southeastern side of the lake, as it is in the topographical position in which we would expect to find it. But the country is a very sandy and duny. The beach is identical with Mr. Gilbert’s number one at the head of the Maumee valley, and hence the suitability of the name. When the water was at this level, Mr. Gilbert regarded the outflow of the lake as by the Wabash River. The divide, at the head of this river, from the Maumee drainage was nearly fifty feet below its surface.§ But it was not then known that this deserted shore extended throughout the Saginaw val- ley to the Michigan basin. Nor had the moderately complete * Geology of Washtenaw County, by A. Winchell, 1881. +.Geology of Ohio, map, p. 549. t Ibid. $ Geology of Ohio, vol. i, p. 551. Great Lakes, and their Deformation. 209 and accurately measured Ridgeway Beach been surveyed, and the warping movements measured therefrom. From the present information, it will at once be seen that the same sheet of water had also access to the Mississippi drainage by the depression at the head of Lake Michigan, which is twenty feet or more below the highest beach in the vicinity, the probable equiva- lent of the Maumee Beach, east of the lake, now about a hundred feet above its surface, near Columbia. ( Elevations of Maumee Beach near: Feet above the sea. Columbia, Mich. (dunes rise to 699 feet)_....---- 683 Allegan (dunes to 749, terrace) ..-.------------- 713 Bastiot Mewamo:(barometric)) 2.14 025.2222. 252 841 Vy] yy as ce ae oe gi ee ere ae ee ea 849 Be invliler ene veel a a a CP SAN CAE SRN ee 817 ap silambi.(GenEace) (254.05. o8ei 28 784 NOTE UE Se Se ee a ee Nein re ee, eee 789 Moni aymer(Gullbert) 2022 22222, 2 1 788 to 778 Glewelanda(Geol Oinio): sess ee 786 Amount of Warping in the preceding Beaches.— Across the State of Michigan, the Maumee Beach records a differential eastward or northeastward elevation of scarcely more than a foot per mile, while that of the Ridgeway Beach in the same direction is a little less than a foot per mile. West and south of Lake Erie the unequal movement is re- duced to almost zero. But east of Lake Erie the uplift reaches two feet per mile as recorded in the Forest Beach. East of Lake Huron, the Arkona Beach rises to the north- eastward at 1-71 feet per mile, and the parallel and younger Forest Beach at 1:5 feet. The still younger Algonquin Beach* rises 1°33 feet, east of Lake Huron. This warping increases so that east of Georgian Bay it amounts to 4:1 feet per mile, in direction N. 25° E. The explored beaches north of Lake Erie have an accelerated rise, so that, northwest of Lake Ontario, it amounts to 3 feet or more per mile, in the higher _ water margins. If the higher shore-lines in the Adirondacks could be and were surveyed we would expect a differential elevation to the northeast of more than five or six feet per mile, as that amount has been measured in the lower L[roquois Beach.t But most of the differential crust movement has been since the Iroquois and Algonquin episodes. figher coast lines.—There were sheets of water pre- ceding the Maumee episode, for across the higher lands of Michigan, there are extensive belts of flat land or plains * “Deformation of the Aleonquin Beach,” ete., this Journ., vol. xli, 1891, p. 15. + ‘‘ Deformation of the Iroquois Beach,” etc., this Journ., vol. xl, 1890, p. 447. 210 J. W. Spencer—High Level Shores of the often covered in part with gravel floors, and in part with silt. They are the exact counterpart of the plains in front of the lower beaches, although more eroded by the streams cutting down to the lower levels. Thus extending from the vicinity of Kalamazoo there is an extensive plain, with a floor of well-rounded gravel, bounded on the south by ridges but with a generally open and descending country to the north. On this plain, [ have traveled for forty miles to eastward of Marshall, and could see in it no other history than that of the bottom of some bay in front of ridges of drift hills towards the south. The barometric height taken from the station at Kalamazoo gives the plain or terrace an elevation of 912 feet above the sea. Farther eastward the measurements reached 944 feet. In the valleys, there are lower river ter- races probably corresponding to the Maumee Beach. The amount of warping in the region is very little. It has also been noted that there is scarcely any deformation south of Lake Erie until passing eastward of Madison, Ohio. It is well known that there are at last four troughs in Ohio connecting the Hrie valley with that of the Ohio River having summit floors at elevations of between 909 and 940 feet above the sea, composed of drift materials, and that there are terraces at the northern end of these valleys.* The terraces at the head of the Mahoning valley is a good example. It is probable that the gravel plains of Michigan and the terraces in Ohio, con- nected with these meridional troughs, are identical in age. But here is rcom for investigation. In Michigan, there are other and higher gravel flats than those just referred to. Professer Rominger records beach-like deposits at 1,682 feet above the sea on the highest lands near the northern part of the lower peninsula of Michigan.t Professor E. Desor noticed other similar deposits at considerable elevations in the _ northern peninsula of that State.{ Mr. A. Murray long ago re- ported a series of beaches on the northern side of Lake Supe- rior.§ Professor H. Y. Hind observed terraces at Great Dog Portage, north of the same lake at 1,485 feet.| Other beaches at 1,100 feet have been reported in Wisconsin. None of these I have seen, and do not know which of them, except those north of Superior, belong to true beaches, for I have every- where had to distinguish between plain shore structures and those forms which go under the name of kames, osar, ete. * Geology of Ohio, vol. ii, p. 47. + Geology of Michigan, vol. iii, p. 19. t See Beaches, etc., between Lakes Mick. and Sup., by E. Desor in Foster and Whitney’s Report, vol. ii. § Geology of Canada for 1863. || Report upon Assiniboine and Saskatchewan Expedition, 1859, p. 120. Great Lakes, and their Deformation. 211 It is due, in part, to the delay in systematic investigation, that we owe our ignorance of the high-level shore-markings in New York. Terraces and delta deposits occur about Seneca and Keuka Lakes and elsewhere in New York. The gravel plain at Horseheads at the divide, south of Seneca Lake valley has an elevation of 900 feet. The valley isa mile or more wide, with free drainage towards the south. Is this shore deposit the equivalent of the Forest or some other beach? In a lateral valley, immediately to the east of Horseheads, there is a well marked terrace at an elevation of 1,200 feet. This terrace-plain could not have been formed unless the waters filled the valley at Horseheads, which is only three or four miles away, to a depth of 300 feet. The terraces of the Genesee River, up to 1,900 feet above the sea, or 250 above the river, and the records north of the Adi- rondack Mountains tell the same story of water everywhere, at elevations indicating one vast sheet, extending over the lake basins, and only obstructed by the great islands of Ontario and Michigan, with beaches far higher than the now numerous val- leys, radiating to the north, east, south and west. The margins by this shrinking Warren Water were constantly contracting, as shown by the beaches, but its full dimensions are not yet known. Until these investigations are further extended, this chapter in the history of the lake regions cannot be completed. Its be- ginning was at the close of the drift episode of the Pleistocene period, and its dismemberment was the episode of the birth of Algonquin and Iroquois Bays, which afterwards became lakes. But whether this great sheet of water existed as an arm of the sea, or a glacial lake, may be questioned by the opposing schools. The absence of marine beaches seems to be an ob- stacle on one side. A sheet of water, at least six or seven hun- dred miles long and four hundred wide, with several, or many outlets upon its southern side, appears still more unfavorable to the supposition of an ice dam to the east, of more than 2,000 feet in thickness, beneath which a river as great as the St. Lawrence was flowing, and continuing for the centuries which carved out the terraces and beaches. Indeed, some of the sea cliffs of the highlands of the Ontario peninsula, as well as terraces and beaches indicate a long wave action. The argu- ments set forth, against the glacial character of the Iroquois and Algonquin Beaches, obtain with greater force when applied to those of the Warren Water. But let these reasons rest in abeyance, and let others enter the harvest field not circumscribed by disputed hypothesis. Am. Jour. So1.—THIRD SERIES, Vor. XLI, No, 243.—Marcu, 1891, 212 H. A. Wheeler—A new variety of Zine Sulphate. Art. XXII—Wotes on Ferro-Goslarite, a new variety of Zine Sulphate ; by H. A. WHEELER. ASSOCIATED with the sphalerite im a zinc-mine at Webb City, Jasper Co., Mo., there occurs a new variety of goslarite, or hydrous sulphate of zine, that contains about 5 per cent of ferrous sulphate. It appears as incrustations and in stalactitic form on the wall of a large body of zine-blende, with which marcasite and galenite are associated. Its origin is due to the oxidation and leaching of the zine and iron sulphides, and their subsequent crystallization as the solution slowly concentrated by atmospheric evaporation. The occurrence of goslarite in the drainage of the mines of that district is quite common, according to Dr. W. P. Jenney, and where the seepage through the ore-bodies is very slight, the normal white to colorless sul- phate of zine is occasionally found as an incrustation on the sides of the mine; but in this case, a double sulphate of zine and iron is found in the ratio of 4:9 FeSO, to 55:2 ZnSO, or nearly as 1:11. Thus far it has been found in only one mine and in very small amounts, which is hardly surprising in a district that is usually seriously troubled with water, when the ready solubility of the mineral is considered. The mineral occurs in mammillary and stalactitic inerusta- tions, with a prismatic, radiating structure. It is subtrans- parent, and light yellow to brown in color. Luster, vitreous. Hardness, 2°5. Brittle. Readily soluble in water, and has a highly astringent taste. Readily loses its water on exposure to the air, turning to an opaque, yellow powder. Fuses with intumescence on charcoal, finally leaving an opaque, brown, infusible mass that is feebly magnetic; otherwise gives the usual zine and iron reactions. The analysis given below shows a very slight contamination (0°8 per cent) from associated clayey matter, Zine sulphate aes es eee RS 55°2 per cent. Ferrous sulphate .-._-. ._-- ArQ), 28 Winter 2 ies es ee 6s SOCOM ies Siliea: Uvaaly eee eae TS js ae Ort as A lumii ae eee to Oe a Mota ete cha 5 99°9 per cent. As the properties of the mineral correspond so closely to those of goslarite, differing only, as far as studied, in the oceur- rence of ferrous sulphate with the variation to be expected therefrom, I have given it the name of ferro-goslarite. I am indebted to Mr. Arthur Thacher, E. M., for calling my atten- tion to it, who first noticed its occurrence at Webb City and placed some of the material at my disposal. Hl. L. Wells—Composition of Pollucite, ete. 213 Art. XXIV.—On the Composition of Pollucite and its Occur- rence at Hebron, Maine; by H. L. WELLs. It is a matter of great satisfaction to announce the discovery of pollucite in a new locality. This very interesting mineral has heretofore been found only on the Island of Elba and even there in very small quantities, so that it may be called a min- eralogical rarity. Its composition, in being the only known mineral in which caesium is an essential constituent, adds greatly to its interest. : Before describing the American material, some account of the history of the mineral may be given. In 1846, Breithaupt described* two minerals from Elba, which he called Castor and Pollux from their great similarity in appearance. He distin- guished them easily however by their difference in specitic gravity. Castor is now considered to be identical with petalite, and it is a fact worthy of mention that the latter mineral is found at Peru, Maine, only a few miles from the new pollucite locality, a fact which points, perhaps, to a new association of “Castor and Pollux.” Breithaupt’s material was analyzed by Plattner,t but at that time caesium had not been discovered, so that he naturally mistook it for potassium. His results were as follows: 1 Plattner. SLO) ie ees eee re a) Soe 46°200 eg eee Bee Cee sake es HOTS 94 Soop sess 5555 5555 5525 655555555555 0°862 Ei ee ee se oS BA 16°506 ree re See ee ok 10°470 NG OPES oe SS BS 2°321 Plattner sought in vain for an explanation of his low results, and, not having enough material to repeat his analysis, he pub- lished it as it was. The discrepancy remained unexplained until in 1864, eighteen years later and after Plattner’s death. Pisani§ discovered caesium in the mineral. Pisani states that. if Plattner’s analysis be re-caleulated on the supposition that the caesium was weighed as platinichloride while the soda was calculated in the usual way from the weight of the mixed chlorides, that the resuits would correspond closely to his own * Pogg. Ann., lxix, 439. ¢ With trace Li,0. + Ibid., p. 446. § C. R., lviii, 714 214 Af. L. Wells—Composition of Pollucite and its analysis. Brush afterwards published a re-caleulation* on this assumption, which is given below under la. Since Plattner used 0°5 gram. of substance for his analysis, the footing still hardly does justice to his well-known skill as an analyst. I have therefore made a new re-caleulation, given under 10, assuming that Piattner’s platinichlorides contained enough potassium to make an exact summation. This assumption is warranted to a certain extent by the fact that all analyses of pollucite since Plattner’s give at least a trace of potash. This calculation of the potash cannot be considered very exact, but it is quite probable that a part of the excess shown by the other re-calculation was due to the presence of this substance. la. 1b. “i Plattner, 0 my Plattner, = ae Re-calculated. Ratio. Re-calculated. Ratio. Si1,0 46°20 ‘770 or 4°64 S10, 46°20 ‘770 or 4°64 Al O. GO? Oh : AIO: £6 39°" 1614S Ro FeO, 0°86 -005 AGG 001100. FeO? 0786 * 005 ie 3 Cs,O 35°69 °127 Cs,0 29°80 -106 } K,O dA Se oS Goto OF93 K,O 2°71 +029 +163 or 0°98 Na,O 172 ‘028 Na,O 1:72 -028) H,O Dae, ‘129 or 0°78 EL 2°32 ‘129 or 0°78 103°18 100:00 The analysis which Pisani made on his discovery of caesium in the mineral, is as follows: 2. 2a. = Ratio with Pisani. Ratio. assumed correction. (Na,O0=2°17 per cent.) 510, 44°08 "734 or 4°56 "734 or 4°56 ALO 15°97 157 ay i . Fe,0, 0-68 004 161 or 1°00 ( 161 or.1°00 CaO 0°65 are Ole Cs, Ot 34:07 Vt - "196 oretl<22 ‘168 or 1°04 Na,Ot 3°88 063 EO 2°40 “133 Or 0°83 "133 or 0°83 101°71 Pisani is very positive about the freedom of his caesia from any considerable amount of potash, and he determined the atomic weight of his alkali-metal in support of this; hence it is searcely allowable to re-calculate his analysis, as has been done * This Journal, II, xxxviii, 115. + With traces of KO and Li,O. Occurrence at Hebron, Maine. 215 in the case of Plattner’s, with the assumption that the excess was due to the presence of potash. It is the author’s opinion, from a consideration of one of Rammelsberg’s analyses which will be mentioned later and of the analyses of the new material from Maine, that Pisani’s excess was at least largely due to too much soda, either derived from glass vessels or from some other cause, hence a ratio is given under 2a above, after de- ducting 1°71 per cent of soda from the analysis. Pisani de- duced from his analysis the oxygen ratio, $10,: Al,(Fe,)QO,: Cau Na )\O> ELO—toro5 2° 2.) This, ratio would be ex- pressed by the very complicated formula, 45810, . 10.A],O, . 12Cs,0 . 12H,0. Pisani certainly left the question of the true composition of pollucite open to doubt, and in 1878 Rammelsberg ‘published* a new analysis of the mineral with the view of clearing up the doubt. Rammelsberg’s material was evidently not well adapted to the purpose of determining the composition of the mineral, for he first picked from it some pieces, “ more or less translu- cent,” and obtained from them, Al,O, 16°58, alkalies precipi- tated by platimic chloride 23°08, Na,O 2°00, Li,O 0°88; then he picked from the same material, some fragments which had a specific gravity of 2°868, the lowest number which has ever been given for the mineral, although Breithaupt gives the same number as the lowest of a series, and he made the follow- ing analysis from it: oe & Rammelsberg, i First analysis. Ratio. SiO, [48°15 | [802 or 5-01] Al,O, 16°31 °160 or 1°00 Cs,O 30°00 106 KO 0°47 "005 "151 or 0:94 Na,O 2°48 040 Ee 2°59 "144 or 0°90 100°00 On this single analysis, where an important constituent was determined by difference and where the material was of ques- tionable purity, Rammelsberg obtains the formula which is now generally accepted for the mineral. The analysis corres- ponds to the formula H,R’,A1,(SiO,),; Rammelsberg includes the hydrogen in R’ and writes it R’,A],(SiO,),. It may be inferred that Rammelsberg himself was not fully satisfied with his results, for about two years later, he pub- lished} an analysis of what he describes as the purest material. * Berlin. Akad., 9, 1878. + Berlin. Akad., 671, 1880. 216 HL. Wells—Composition of Pollucite and its This analysis is given below: 4. Rammelsberg, Ratio from the New analysis. mean of 4. i es SS aN a Sa? ean ey ee 16 IE, ‘bats SiO, 46°48 ie Mae ‘775 or 4°58 or 9°16 AOS ee ee 17°24 ee ‘169 or 1°00 or 2:00 Cs,O ee SPE 30°71 30°53 "109 K,O 5 ae 0°78 0°41 "006 + °151 or 0°89 or 1°78 Na Or eee 2°31 PANS) "036 3°30 H,O 2°32 fe aati rose “129 or 0°76 or ¥52 He does not publish any ratio with this analysis, but says: “ These results confirm the former.” The emphasis is Ram- melsberg’s. It may be noticed, however, that this analysis corresponds very closely to the formula, 9Si0,.2A1,0O,.2R’,O. 13H,O, or, putting in H with R’, it corresponds very well with the metasilicate formula, R’,Al,(SiO,),. Moreover the formule just mentioned correspond much better with the analyses of Plattner and Pisani than Rammelsberg’s formula does. What the probable formula for pollucite is, will be dis- cussed after giving the analysis of the Hebron mineral. The locality, Hebron, from which the new material comes, furnished the lepidolite from which Allen * extracted a large quantity of caesium and rubidium, the material used by John- son and. Allent in determining the atomic weight of caesium as now accepted. Hebron also furnished the remarkable beryl in which Penfieldt found 2°92 per cent of caesium oxide. It might have been expected, therefore, that this locality would be likely to furnish pollucite; indeed, Professor Brush tells me that he has tested a large quantity of quartz fragments from the locality, hoping that some of them might be this mineral. The specimens were found during the past summer by Mr. Loren B. Merrill, of Paris, Me., and a few pieces were sent by ~ him for identification to Professor Brush, who very kindly gave them to the author for examination. Mr. Merrill has . since very generously loaned us his whole stock of the mineral, amounting to more than half a kilogram, in order that a thorough examination might be made. The mineral is said by the discoverer to have been found in eavities.§ It was associ- * This Jour., IJ, xxxiv, 367. + This Jour., IJ, xxxv, 94. t This Jour., III, xxviii, 29. § Mr. Merrill says, in a letter received after this article was in print, that the pollucite was found in only two cavities. In one of these only two or three pieces were found, associated with large, etched quartz crystals. In the other cavity the main part of the mineral was found in a loose heap mixed with clay. This last cavity was open at the top, and was 3 feet wide 6 feet long and 18 inches deep. Occurrence at Hebron, Maine. 217 ated with quartz, a crystal of which was in one case imbedded in the pollucite, also with psilomelane and with another mineral which proves to be a nearly colorless, brilliant caesium- beryl. The pollucite was in the form of irregular fragments, mostly between + and 10 grams in weight, very similar to those figured by Breithaupt in his original description of the mineral from Elba. The substance of many of the fragments, such as were used for the analysis, was of the most perfect physical character, perfectly colorless and as brilliant and transparent as the finest glass. Prof. S. L. Penfield has kindly made the following report of an optical examination of the substance : “ Refractive indices on a prism of 43°41’: = HO Im = 1524 7Na ic! NORA) 80) ~The mineral shows no double refraction, hence it is iso- metric. Under the microscope it is very free from inclusions. Some of the specimens show a series of holes, in parallel posi- tion, extending into the substance of the fragment at right- angles to its surface. These holes have rectangular cross- sections and they give to some of the specimens a sort of fibrous structure.” Unfortunately, none of the fragments have any distinct crystalline faces. In its pyrognostic properties, its luster and hardness and its lack of any apparent cleavage, it agrees exactly with the obser- vations of Breithaupt, Plattner and the other observers in regard to the Elba mineral. It is completely, though slowly, decomposed by hydrochloric acid with the separation of pul- verulent silica. This agrees with the observations of Plattner and Pisani, but not with the statements of Rammelsberg. The latter was doubtless deceived by the slowness of the action, for it takes several hours to decompose the finely pulverized mineral with moderately concentrated acid at the heat of the water-bath. The specific gravity of the Hebron mineral was taken twice on each of two fragments; one gave 2°985 and 2-987, the other 2°976 and 2°977. It will be noticed that the Maine mineral is considerably heavier than that from Elba. Breithaupt gives 2°368, 2°876, 2°880 and 2°892; Pisani gives 2°901; Rammels- berg gives for the material used in his first analysis 2°868, and for the pure material used in his second, 2°885 to 2°896. All of this European material, except that used by Rammelsberg for his first analysis, is described by the various observers as being colorless and transparent. The indications are that the higher specific gravities represent the better material, and 218 A. L. Wells—Composition of Pollucite and its the comparatively high specific gravity of the American mineral seems to point to still better quality if not to some difference in composition. A single piece of the very best quality was selected for the chemical examination, while the water was determined in two other fragments also, because of the evident importance of the water in calculating the formula. Analyses I and II were first made, but, as they did not show a perfect agreement in the determinations of the alkalies, No. III was then made with the greatest care. This last is considered the best of the analy- ses and the ratio given is calculated from it, but it will be noticed that the other two analyses confirm this quite well and that they both point to the same formula with almost equal sharpness. Water was determined by loss by ignition, as given in detail beyond; the “intense ignitions” were made in small platinum crucibles over a powerful blast-lamp flame, so that the heat obtained was very high. The material was not dried in any way before weighing. The mineral was decomposed by hydro- chlorie acid, and silica, alumina and lime were determined by the usual methods, care being taken to take account of the slight impurities in the silica and alumina. The alumina con- tained a very faint trace of iron, no more than might have been introduced by breaking the mineral up with steel cutters ; no evidence could be found of the presence of other elements in the alumina. The identity of the lime was shown by the spectroscope. The alkali-metals were weighed together as chlorides, then caesium and potassium were separated and weighed as platini- chlorides; the alkali-chlorides in the latter were separated and weighed in order to calculate the proportion of caesia and potash. The potassium spectrum was detected from these last chlorides with considerable difficulty, while they showed no rubidium spectrum whatever. Lithium chloride was separated from sodium chloride, after the removal of the excess of platinum, by the method of Gooch, and the soda was ealeula- ted from the difference between the other chlorides and the total mixed chlorides, while in analysis III the sodinm chloride was also weighed directly, giving a result which happened to be exactly identical with the indirect determination. This agreement of the direct with the indirect determination of the soda may be considered as an indication that the other alkalies were determined with reasonable accuracy. The lithium was identified with the spectroscope. Occurrence at Hebron, Maine. 219 The following are the results of the analyses : Weight of substance taken --- Loss by heating at 125°-130° Loss by heating at 165°-170° Loss by heating to red heat__- Loss by intense ignition -----_- The ratio calculated Two separate Single piece. pieces. SSS SS SSS sip HE TEE VE: Wi eae 0°6260 11291 09491 1°0205 1°4826 Beeps es Se ee 0°00 hese fe tea Eee se 2s ae ome ot 0:03 0°01 Betas 1°49 tai 1°50 1°56 1°50 eee 0°04 efugees bem ts 0°02 0°03 aed from No. III, and the caleulated com- position, giving the alkalies the same proportion as-in the analysis, but omitting lime and lithia as insignificant, is given below: Hebron Pollucite. Calculated for Ratio from analysis III. H2R’,A1,4(Si03)o ——— (R148 Cs, 73a K, Hs Nas) SiOpe ae "725 or 4°53 or 9:06 SiO) Se ree 43°55 NIC Osta s °160 1" Ue EAE Ogee ore eee 16°45 CAaOmess 004 Os5 OR a res hare 36°38 Cs,O0 Be S128 | K.O ay es ee 0°48 Ke Oster "005 \ "166 1:04 2:08 Nain Oa ae pes 1°69 Nas Oo. s. "027 | H.O ie ep eae te eaten te 1°45 iO! oes 002) | a HO sie. "083 0°52 1:04 100:00 The sharpness of the ratio and the agreement of the analysis with the calculated composition are all that could be desired. There can be‘no doubt, then, that the composition of the Hebron mineral is represented by the formula 9Si0,.2A1],O,. 2R’,0.H,O or H,R’,A1,(SiO,),. The theoretical composition for H,Cs,A1,(Si0,),, supposing no alkalies except Cs,O to be present, 1s, 100°00 A comparison of all the ratios given in this article, as shown in the following table, makes it probable that the new formula * Not including, respectively, 0°03 and 0°01 per cent of water lost at 165°-170°. 220 ££. W. Morley— Volumetric Composition of Water. can be assigned also to the Elba mineral. The ratios have been calculated with Al,O, as unity because it shows less varia- tion throughout the analyses than the other constituents. Ratios. (ao _“"— Tae SiO. 2 Al,03(Fe203): R’,0 2 H,0O Plattner’s analysis as re-calculated by Brush____ 4°64: a : 0°93 : 0°78 Plattner’s analysis newly re-calculated_________ 4°64: i” > 0798 2 O-7sS Pisant'Stanalysis* 220s 2c 0 eee eee See 4°56: hy ; 1°22 : 0°83 Pisani’s analysis with assumed correction -~----- 456: us : 1°04: 0°83 Rammelsberg’s analysis on which he based his LOPMU A 02 Sea ee Ae es eee [5°01]: ile : 0°94: 0°90 Rammelsberg’s later analysis_____._.-_--___-- 4°58 : it: :. 0°89)¢) Gale Analysis of Hebron pollucite ___.____---.____- 4°53 : IE : 1°04: 0°52 Proposed formula requires _____..-__-_.----_- 4°50: i: : 1:00: 0°50 Rammelsberg’s formula requires -...__-------- 5°00: A : 100+ 108 H-~--SY Or, as he writes the datier*= 2, ees ee 5°00: te : 2°00 Leaving out of consideration Rammelsberg’s first analysis, there can be little doubt that the new formula expresses the composition of Elba pollucite as far as the first three members of the ratios are concerned, but the water is 0°8-0°9 per cent higher in the analyses of that material than the formula re- quires. that I cannot at all see in Mr. Branner’s paper enough evidence to support the theory that these rocks are eolian sandstones, while it appears to me certain that they are nothing more nor less than raised reefs of different ages. Norse.—Mr. Branner is quite correct in calling attention to the names given to various portions of the island by English and French travellers, which names are quite unknown to the natives. The map published by the Geographical Society from our plan contains most of those really known to the inhabitants. One or two spots which were absolutely unnamed we gave English names to. As to Ilha Rapta as I have called it in this paper in deference to Mr. Branner, all the inhabitants assured us that it was Ilha dos Rattos (i.e., Rattos pequenos), but it is likely enough it was originally called [Ilha Rapta and the name was altered since. Art. XLIX.—The Cause of Active Compressive Stress in Rocks and Recent Rock Fleaures ; by T. MELLARD READE, C.E., F.G.S., ete. I HAVE read with much interest the account of a recent rock flexure on the lower Fox River about six miles northeast of Appleton, Wis., by Mr. Frank Cramer.* The rocks appear to have been in a state of stress from lateral pressure beyond any- thing that could possibly be due to gravitation and irregularity of the ground. This stress may have been and probably has been accumulating for a great length of time, the excavation described giving the needed release or in other words acting as the trigger that set off the gun. If the effect of the small anticlinal ridge thrown up had not been to crack the walls of the paper mill and dislocate the machinery, the probability is that the movement would have gone unnoticed and it is most: likely that such small readjust- ments of the earth’s crust take place with greater frequency than is suspected. There is, however, one surface phenomenon which will tend to minimize accumulation of lateral pressure * This Journal, March, 1890, pp. 220-225 410 TT. M. Reade—Cause of Active Compressive Stress and that is the greater development of jointing in the surface rocks. Joints are widened by atmospheric agencies so that the surface rocks are frequently cut up into blocks not in actual contact. This is very noticeable in the sandstone quarries in Darley Dale, Derbyshire, where the joints are sometimes filled with infiltrated bowlder clay. It is evident that if the surface rocks are not continuous over a considerable area the throwing up of the anticlinal ridge could not take place because there could be no accumulation of — lateral stress. There is no doubt that alternations of temperature take place in deep seated rocks, causing their bulk to undergo considera- ble variation. These rocks, owing to the pressure they are subjected to, are in absolute contact and form a homogeneous mass. I have attempted to show (Origin of Mountain Ranges, Chap. XX V), that the sudden release of these accumulated stresses, whether of tension or compression in deep seated rocks, is the cause of earthquakes that happen away from vol- canic centers, and also that earthquakes are more frequent and greater in intensity in areas occupied by the newer rocks such as the Tertiary in all parts of the globe. It is in these areas that the greatest underground fluctuations of temperature occur in the crust of the earth. While my work was going through. the press, the earthquake that ravaged Georgia and South Carolina, known as the Charleston earthquake, occurred on the night of August 31, 1886, thus emphasizing in an unfortunate way the principles I had expounded. The substratum here is of Tertiary rocks and the area was not recognized as one of great seismic activity. On the contrary an eminent geologist had only just before been insisting upon the great stability of the Atlantic borders of the North American continent. These changes of temperature cannot, however, excepting in a secondary manner affect surface rocks, for they are kept by atmospheric influences at the mean temperature of the station _ at which they occur; we may therefore dismiss change of tem- perature of the surface rocks themselves as a vera causa. The uplift on the Lower Fox River, though a striking exam- ple, can be paralleled by other instances of lateral pressure in surface rocks disclosed in the process of quarrying, suggesting a similar release of accumulated stress by unloading. Professor Kenny Hughes gives an instance (Geol. Mag., 1887, p. 511) of the bursting up of the floor of a limestone quarry at Dent Head and also of the floor of a tunnel at Ribble Head in Yorkshire, but he attributes these, whether rightly or not I am unable to say, to the fact that the beds rest on shale, inferring that the unequal pressure caused by the removal of part of the rock in Rocks and Recent Rock WEclewunes: AT forced up the shale as a viscous mass and so breaking the lime- stone bed above it. It is evident, however, that this explanation will not meet the cases mentioned by Professor W. H. Niles where the phe- nomenon of lateral pressure he describes have acted over a considerable area and under diverse conditions of rock struc- ture.* At Monson, Mass., the quarry was in a belt of gneiss lying east of the red sandstone of the Connecticut Valley. The strike of the gneiss is north 10° east and the dip 10° north at the high angle of 80°. The pressure as seen by the move- ments of the beds in the quarry appears to have been parallel to the strike or at right angles to the movement that originally flexed the beds. At Berea, Ohio, the quarries in which movement was observed are in sandstone (berea grit of the Waverley group), lying nearly horizontal and the movement was in a north and south line. At Lemont, Illinois, the quarries were in the Niagara lime- stone and an anticlinal axis was formed striking east and west 800 feet in length and rising from 6 to 8 inches in the most conspicuous parts. ‘It was formed along the line of vertical joint which extends beyond the limits of the quarry. The con- tinuous edges of the bed were bent upward, making an eleva- tion which was a little more upon the north side of the joint than upon the south and a slight fault was in this way pro- duced.” Another quarry referred to is at Waterford, Conn., in gneiss, and another quoted from Professor Johnston is in sandstone at Portland, Conn. Professor J. Johnstont says that these sandstone quarries are of great extent and 120 feet deep from the original surface of the ground. A groove about a foot wide and 80 feet long was being cut in a bed about 6 or 7 feet thick and in an east and west direction parallel to a natural joint. When the channel had been sunk to within - about 9 inches of the bottom of the strata the remaining stone was crushed to fragments with a loud report and the walls of the groove had approached each other within about three- quarters of an inch. Other similar movements occur and these take place in a northerly and southerly direction and not in an easterly and westerly line. i In explanation of the Lower Fox River uplift, Mr. Cramer ealls attention to the suggestion of Mr. Gilbert that such-like movements may have arisen from the expansion of the rocks * The geologic agency of lateral pressure exhibited by certain movements of rocks. Proceedings of Boston Soc. of Nat. Hist., vol. xviii, 1876. + Proc. of the American Assoc. for the Advancement of Science, Eighth Meet- ing, (1854), 412 TL. M. Reade—Cause of Active Compressive Stress consequent on a rise of temperature since the Glacial Period.* If the Glacial Period had been sufiiciently prolonged to have affected the isogeotherms down to a considerable depth where the rocks are in tightly compressed contact, it is conceivable that the rise of temperature in the Post-glacial Period—again assuming a sufficient length of time has elapsed—may have been enough in some instances to create a low domical uplift, but it does not seem to me to be likely that the pressure from this cause could accumulate in surface rocks subject to atmo- spheric changes over such extended periods. Before committing myself even to any suggested explanation of these extremely interesting phenomena I was desirous of ascertaining whether the districts described were affected by faulting, and if so to what extent and in which direction. Professor J. W. Spencer, who was staying with me at the time, kindly offered to make enquiries, but I am sorry to say the result has not been very encouraging, indeed very barren. As regards Ohio the State Geologist, Mr. Edward Orton, says that faults are exceedingly rare in Ohio geology but joints are finely shown at Berea; the master joints being a few degrees north of east and the main joints of all the Ohio rocks as far as he can recall the facts, except in one instance, have the same direction. It appears to me that the cause of these active evidences of lateral pressure must be sought in the differential movements to which it is well known the crust of the earth is subjected. Since the Glacial period, in the British Isles, there are the strongest evidences of vertical movements both of subsidence and elevation having taken place. Having paid great atten- tion both to Postglacial and Glacial geology during the past twenty years I consider the evidences are overwhelming. Since the marine bowlder clay of the plains was laid down there have been two movements of elevation and two of de- pression to the extent of several hundred feet+ but as the evi- dences of maximum movement are submerged we cannot estimate it. The well known sand and gravel glacial drift with shells on Moel Tryfan, North Wales, at an elevation of nearly 1400 feet above the sea has long been taken by most English Geologists as convincing evidence of a vertical movement of elevation to that extent since the beds were laid down and notwithstanding the views of some extreme glacialists I must be pardoned if I still- consider them a monument of geologi- cally recent elevation. It is true some of the American geolo- * “Some Geologic Wrinkles,” Proc. of American Assoc. for the Advancement. of Science, Thirty-fifth Meeting, 1886. + Geology and Physics of the Post Glacial Period, ete. Proc. Liverpool. Geol. Soc., Session 1871-2. in Rocks and Recent Rock F lexures. 413 gists full of scientific enthusiasm have like the late Mr. Bell explained the Tryfan sands and gravels and in addition our bowlder clays as sea bottom pushed up by land ice; but twenty years’ careful work in the drift leads me to utterly disbelieve in the universality of this agency. Unless we are to throw on one side all the usual methods of geological investigation it were difficult to believe that current bedded and stratified sand and gravel full of shell fragments to all appearance exactly like a modern beach has been pushed up and landed on the top of a mountain spur—a spur of Snowdon in fact. If the inexorable logic of glacial. events in America requires this interpretation I for one prefer to consider that there must be some great flaw in the premises. Still whoever is right on this point, evidence has been accu- mulating rapidly on the American side of the Atlantic of glacial and post-glacial elevations and subsidences on a much more prodigious scale. According to Dr. George M. Dawson there have been orogenic disturbances both to the east and west preceding and during the Glacial period amounting to in one case not less than 3000 feet. Laurentian rocks derived ‘from the east are found at elevations on the west amounting to in round figures 4000 feet and several thousand feet above their possible origin. He is of opinion that the subsidence of the Cordillera region of the west was accompanied by an ele- vation of the Laurentian highlands of the east. All these facts are set forth in his highly interesting presidential address to the Royal Society of Canada.* The ancient beach lines of the Great Lakes as shown by Gilbert and Spencer evidence considerable differential vertical movements and the latter sees proof from buried river chan- nels and other evidences that the American continent within geologically recent times stood several thousand feet higher than at present and more recently several hundred feet lower. The communication by Prof. J. D. Dana ‘On the Long Island Sound in the Quaternary Erat points also to considerable ditf- ferential movements. Mr. Warren Upham has also enumerated a great many instances of Quaternary changes of level in a paper in the Geological Magazine.t The Pacific coast in California according to Prof. LeConte and Prof. Davidson of the U. 8. Coast Survey give additional evidences of former elevation in the existence of subaqueous river channels as well as evidence of another character existing in some of the islands. * Trans. of Royal Soe. of Canada, vol. viii, Sec. IV, 1890. + This Journal, Dec., 1890, pp. 425-437. ¢ Quaternary Changes of Levels, Geol. Mag., Nov., 1890, pp. 492-497. 414. 7. M. Reade—Compresswe Stress in Rocks, ete. Taking then for granted the prevalence of these vertical movements in recent geologic times it is obvious that the sub- sidence of a low arch of elevation must tend to put the sur- face rocks into lateral compression. This will be largely governed no doubt by the existence or non-existence of faults and joints, and it is readily seen that when the strata are com- paratively unbroken and continuous as in Ohio the most favor- able conditions prevail. Doubtless the surface rocks adjust themselves to such movements by these anticlinals where they exist and minor subsidences may locally occur. In the Iro- quois Beach the rising grade appears to be in a northeasterly direction and to vary from 1°60 feet to 6 feet per mile.* Were this arch to subside to the horizontal it would be quite sufficient to develop considerable lateral pressure in the surface rocks. So long as the limit of elasticity of the rocks is not exceeded it is quite conceivable that the energy may have been stored up for a great length of time only wanting favorable conditions for its release. It would take too long to discuss in one paper the cause of these differential vertical movements, but I would refer those interested to Chap. XXII of the Origin of Mountain Ranges where the larger bendings of the earth’s crust are treated of. To call in the usual explanation of all lateral pressure phe- nomena, viz: tangential thrust arising from the shrinking of the earth’s nucleus, is to call im an agency which were it the true one would have a more universal effect. The fact that these conditions of active lateral pressure in surface rocks are recorded as unusual raises a strong presump- tion that tangential thrust is not the potent agent in geologic change that some maintain, for were it so most of the surface crust would on artificial penetration exhibit powerful signs of pent up energy, for it was clearly proved by me in 1886 and shortly afterwards independently by Mr. Davison that in a cooling solid globe the greatest compression takes place on the surface and the same reasoning applies as I have shown in the same work to a globe witha hard crust of the requisite thick- ness even if the nucleus be molten. Park Corners, Liverpool, England, Jan. 2, 1891. * The Deformation of the Iroquois Beach, by Dr. J. W. Spencer. This Journal, Dec., 1890, p. 447. W. P. Headden—New Phosphate from South Dakota. 415 Art. L.—A new Phosphate from the Black Hills of South Dakota; by W. P. HEADDEN. THE mineral described in this note was found in the Nim- rod, now called the Riverton, lode, near Harney City, Pen- nington Co., South Dakota. It occurs in the granite common to the district, in kidney-shaped masses, some of them weigh- ing upwards of fifty pounds, but they are not numerous. Externally they are dark brown, due to oxidation which has taken place, in some cases, to the depth of a quarter of an inch, in others only on the surface. These masses enclose a few crystals of white mica, but are not penetrated by crystals of this mineral which often adhere to the surface. Some of them show small seams of an almost white mineral with two cleavages nearly at right angles to one another; its composi- tion has not been determined. It is easily recognized under the microscope, especially in polarized light upon which it acts strongly, while the inclosing mineral has no effect upon it. In places there are dark patches visible only in pieces thin enough to transmit light. The mineral is amorphous and by reflected light has a dark brown color; by transmitted light in very thin pieces it is a yellowish brown, in thicker ones a brown color. It has a resinous-vitreous lustre, an uneven to conchoidal frac- ture and no cleavage. In thin flakes it is translucent to trans- parent. Specific gravity, 3-401; hardness, 5:5 and is brittle. It is readily soluble in acids, fuses easily in the flame of a candle and reacts for manganese, iron and soda, before the blowpipe. The material for analysis was carefully selected, only such pieces being taken as were thin enough to show by transmitted light that they were free from the dark patches and macro- scopic seams. ‘I'he results were as follows: If II. III. IV. Whe Mean. Oxygen. On aeee! SS. oil 38°22 38°45 38°49 38°86 38°52 WALT) 2-17— 1 Mn@ 3.2 329:74 Bg) AL 28°97 30°08 ble 29°64 0668 ) Ca Oe 2s TO 7°66 766 7-08 7:28 an ‘0213 BA Oane 9 94a ee hOc ston O09 ages OSA lO sonay OA 2 MeO n ss Snr ianSs 4:14 4-01 4-00 his os 4-00 “0089 MeO) = 250714 pyoes 0:16 Bh cgi aoe 0°15 "0006 L1-97T 0°91 INazOles) 6:52 aoe he 552 0142 One. (02014 SE aa 1 ie 90:50) 1 00105 His0.2_. trace ten trace =o eae trace Les Op sn 4) 157 el Pen Re Mebane Red 11) 4:29 +0382 J Ci eee 0°11 wes NOUACtss es - pie 0°11 ee eee trace ig ae Pas: eee trace insole ase (014 Eaiegs 0°18 eae eat 0°16 100°18 99°65 100:°29 416 W. P. Headden—New Phosphate from South Dakota. This ratio approaches 1:1 and includes the water as basic and the whole of the iron as FeO. If the water be considered -as water of hydration, the oxygen-relations cannot be expressed by any simple ratio. If instead of computing the oxygen alone we reckon the atomic equivalents we obtain as favorable a ratio; for, substituting an equivalent number of bivalent atoms for Al,” we obtain for the ratio of P: R:O=1:2:49:5:18 instead of 1:2:5 or 2:5:10 corresponding to the formula P,R,O,, which is a salt corresponding to the normal phosphoric acid H,PO, and in which R= (MnCaFeH,Na,)?+Al4. Other complete analyses, than those given were made of less care: fully selected material with closely agreeing results. I would propose to call this new phosphate Griphite, froin ypipos puzzle, in allusion to its unusual and somewhat enig- inatical composition. A Phosphate near Triphylite from the Black Hills. A mineral, associated with beryl and spodumene, occurs in nodules in the granite of the Nickel Plate tin claim, Penning- ton Co., South Dakota. The inner portions of these nodules are nearly free from other minerals while the outer portions contain some small bunches of mica, a few isolated, black, pris- matic crystals, which are brown by transmitted light, and here and there small patches of a light brown mineral with resinous luster. conchoidal fracture and one distinct cleavage. Neither the black erystal nor the light brown masses seem to be derived by decomposition, from the surrounding mass as it is wholly unaltered.* The mineral forming these nodules, is, in the mass, dark green, in thin splinters, it is translucent to transparent and is a light yellowish green; it fuses easily on the edges of thin pieces in the flame of a candle, to a dark brown, magnetic globule and colors the blowpipe flame a faint yellow. It has a hardness of about 5, a specific gravity of 3°612; cleavage in two directions, in one it is perfect in the other it is quite im- perfect and the directions are not at right angles to each other. The lustre is vitreous and the fracture uneven to small con- choidal; streak and powder very light green, almost white. When exposed to the atmosphere for a short time it darkens externally due to oxidation. The-freshest material was taken for analysis which gave the following results : * Subsequent examination showed the black prismatic crystals to be crystals of cassiterite with the usual combination of the pyramid and prism, the prism being very strongly developed. Many of these erystals are fretted to such an extent that they form almost skeleton crystals. E. Merritt—Peculiarities in Behavior of Galvanometer. 417 ify II. Mean. At. Eq. IE KOs eee ae 38°D2 0s) 38°76 38 64 54°16 54°66 1 INCOR ee 25°29 24°82 25°05 34°78 | Mm@ m= se 2 15°45 15°64 15°54 17°40 CAOeeo enue 5°42 5°64 5°53 9°$7 Mo@nt= 3. 1°56 144 1°50 4:00 +} 81:20 15 ING Oe 2S e 7:46 (7:46) 746 (Re) 12°02 Re ORs. s 2°00 (2°00) 2°00 2:12 | Win One se Le (28) 28 "28 os 1°00 J Th eS Pease 69 (0 69) [OOM mMOxayiRen! emi itonas. ame Gs (0°73) 1S) 223° 223°00 4-09 Ganeuees=- R49 244 2°47 99589 99°88 99°89 This ratio 1:1°5:4:09 or 2::3:8 indicates RPO, as the formula for the mineral in which the ratio of R,: -Ris1:44 or 2:9 giving as molecular formula a(R, Nyse O+9R, P,O, or better 4R, PO,+ OR nO ea Line Ee of R, PO, to R, P,O, in triphyl- ite is 1: 1 but here it is 1: 24, too wide a deviation to admit of their being regarded as identical. ArT. LL—Wote on Certain Peculiarities in the Behavior of a Galvanometer when used with the Thermopile ; by ERNEST Merritt, M.E. (Contributions from the Physical Laboratory of Cornell University, No. 8.) WHEN a galvanometer, whose needle is not too thoroughly damped, is used in connection with a thermopile, a curious phenomenon is observed. On suddenly exposing one face of the pile to some source of radiant heat, the needle of the gal- vanometer moves quickly to one side. In a short time, however, the motion becomes less rapid, and in the course of a few seconds the needle comes to rest, and in many cases moves backward for a short distance. This behavior is then repeated, and it is only after a long series of such throws, which gradually become less and less marked, that the final steady deflection is reached. The curve OAB in ie ie rep resents graphically this peculiar motion as observed in the case of a Thomson tripod galvanometer, the abscissa of any point on the curve showing the time that has elapsed since the beginning of the motion, and the corresponding ordinate being proportional to the deflection of the needle from its position of rest. With a galvanometer whose needle is more nearly ‘dead beat” the maxima and minima which are so clearly shown in the figure, may not be present; but the general form of the curve will still be the same. 418 £. Merritti—Certain Peculiarities in Behavior of a The effect described above was noticed in 1884 by Violle * while using a thermopile to investigate the radiation of molten platinum and silver. Numerous observations of successive maxima and minima are given in his paper; but no explana- tion of the phenomenon is offered. Messrs. Rubens and Ritter have observed a similar phenomenon with a peculiar form of bolometer which they used for quantitative measurements of electromagnetic waves;+ and numerous experiments that have been made in the laboratory of Cornell University with a bolometer of the ordinary type, and with a number of different galvanometers and thermopiles, seem to show that this be- havior is not peculiar to any one instrument, but is always observed when a bolometer or thermopile, in circuit with a galvanometer, is suddenly exposed to radiant heat. My attention was first called to the phenomenon in 1888, while engaged in an investigation of the energy of the light from incandescent lamps. In a papert published during the fol- lowing year I called attention to the fact, which at that time rested only upon experimental grounds, that the first throw of the needle, under the circumstances described above, bears a constant ratio to the final deflection, this ratio being indepen- dent of the intensity of the radiation to which the pile is ex posed. * “Sur letalon absolu de la lumiére.”” Annales de Chimie et de Physique, V1, lily p: ods: + *‘ Bemerkung zu den Hertz’schen Versuchen tiber Strahlen electrischer Kraft,” Wied. Ann., vol. xl, p. 63. {Some Determinations of the Energy of the Light from Incandescent Lamps,” this Journal, vol. xxxvii, p. 167. Galwanometer when used with the Thermopile. 419 The phenomenon appears to be due to the inertia of the galvanometer needle, and to the fact that a considerable time elapses after the pile has been exposed to a source of heat, before a constant temperature is reached. On account of its inertia the needle is unable to follow immediately the rapidly increasing current that flows when the face of the pile is first exposed. In a short time, however, the continued action of the deflecting force imparts sufficient velocity to carry it not merely to the position which corresponds to the current then flowing, but to a considerable distance beyond this point. The result is that the motion of the needle is stopped, and a retro- grade movement begins, whicn continues until the pile has been heated sufficiently to cause another throw forward. This behavior is then repeated until the temperature of the pile has become constant, or until the oscillatory motion of the needle has been destroyed by damping. If it be assumed that the heating of the pile takes place in accordance with Newton’s Law of Cooling, and that the electromotive force of the pile, throughout the small range of temperatures with which we have to deal, is proportional to the difference in temperature between the junctions, the equation of motion of the needle may be derived as follows : Let T, be the final difference in temperature between the two faces of the pile, and T the difference at any time? Then the current in the galvanometer is given by the equation: ie edhe eal WOR aks k being the radiation constant of the surface of the pile, and P the electromotive force developed by a difference in temper- ature of one degree between the two junctions. The couple due to the action of this current upon the needle, and tending to deflect it, is K zm Z cos 6, 6 being the deflection, and K a constant depending on the form and di- mensions of the galvanometer. Since @ is always small, cos @ will never differ appreciably from unity. If, therefore, we KmtP b R yi Q, the expression for the deflecting couple is reduced to QT, (l-e™). The only other forces that act upon the needle are the return force of the earth’s field, which for small deflections is equal to N@, and the retarding effect of damping. The latter force being proportional to the velocity of the — ° —e") (1 substitute for 7 its value as given in (1) and replace needle, may be represented by L ae These three forces may now be equated to the product of the moment of inertia of the 420 EF. Merritt—Certain Peculiarities in Behavior of a needle into its angular acceleration, and thus lead to the fol- lowing equation of motion : OD eS ON ee) ae The solution of this equation consists of two parts : (1) the general solution of the “complementary equation ” obtained by equating the left hand member to zero; (2) a special solution of the complete equation. The first is "readily seen to be the ordinary expression for the motion of a damped needle: 2 i= Cex cos (= + v) (3 while an easy application of the symbolic method to the com- plete equation gives the following special solution : _Q a QT, kt "> NU Moe been | (4 The complete solution of (2) is the sum of these two parts, and when simplified by the substitution of single letters for the complex coefficients that arise during the integration, gives the following expression for 0: +N 6=QT, (1—&-*) (2 9 G=—C &” cos (<= + y)—m fe ort a ie, (5 The two constants of integration C and @ are determined from the consideration that when ¢ is equal to zero, both @ and a6 are also zero d t ; ue 2 4 7° 2 t c=21,| [ 17 (k—h)+th] aaa (m—/) 5 7 l—in COs P = [oun a= ens It will be observed that all the coefficients in (5) contain T, as a factor, while ¢ is independent of T,. The equation may therefore be written : C= aly le é—" cos at p)—m +1] (6 The motion represented by this equation evidently possesses all the characteristics of that shown in fig. 1. It may be looked upon as resulting from the combination of two motions, one of them being a steady increase of deflection in accordance with the logarithmic curve represented by the last two terms of the equation, the other a motion of oscillation with grad- Galvanometer when used with the Thermopile. 421 ually diminishing amplitude, as indicated by the first term. Evidently zc is the period of vibration of the needle, and a its logarithmic decrement. To test the above equation a series of observations was made with a Thomson tripod galvanometer, every precaution being taken to secure a constant source of heat, and to avoid errors due to draughts of air, magnetic disturbances, etc. The period of vibration of the needle, and its logarithmic decrement (with the thermopile in circuit) were first determined by the ordinary methods. Data for the curve shown in the figure were then obtained by recording on a chronograph the times of the successive maxima and minima, and the time at which the needle passed each tenth division of the scale. Assuming that the equation derived above truly represented the motion, I then attempted to analyze the curve into its two components, and after a few trials obtained the curves II and II! of fig. 1. These two, when combined, give exactly the motion that was observed, while both are capable of being quite accurately represented by equations of the form indicated in (6). For example curve II was found to agree closely with the equation: eae Me OG) eee | (7 the differences between observed and computed values of 6’ in no case exceeding two per cent. The time of vibration of the needle, as computed from curve III, was found to be 6:1 seconds, while that observed when the needle was allowed to swing freely, was 6-0 seconds. The observed and computed values of the ratio of damping show a similar close agreement, being equal to 1:28 and 1:31 respectively. . The fact, which has already been mentioned, that the first throw of the needle bears a constant ratio to the final deflec- tion, is confirmed by equation (6). Since T, is a factor of the right hand member of the equation, and since the expression inside the bracket is independent of T,, the only effect of a change in the intensity of the source of heat would be to in- crease or diminish all the ordinates of curve I in the same proportion, the ratio of any two ordinates remaining the same. If, therefore, the final deflection of the needle is proportional to the quantity of heat received by the pile, the first throw will also be proportional to this quantity, and may im all cases be used instead of the final deflection. Experiments made in 1888 to test the above conclusion showed the ratio to be con- stant for deflections ranging from 100™ to 20™", but for smaller deflections there was apparently a deviation from the law. I have therefore repeated the observations, using great 422 Merritt—Peculiarities in Behavior of a Galvanometer. care to avoid as far as possible all sources of error, and obtain the following results as the mean of a number of measure- ments: First throw. Final deflection. Ratio. VAY oe ee 196:0) =™, 0-270 36°5 1367 0 265 j Mfr 5) 65°0 0-273 S74, 19°75 0°265 The slight irregular variations which occur might easily be _aecounted for by the wnavoidable errors of observation, especially as the source of heat, an Argand burner, could not be relied upon as perfectly constant. The conclusion that the ratio is Independent of the deflection, seems therefore to be justified, at least in the case of the galvanometer used in these experiments. The importance of this conclusion will readily be seen by those who have had occasion to use a thermopile for accurate measurements of radiant heat. Draughts of air, and other almost unavoidable sources of temperature variation, frequently make the galvanometer quite unsteady, while the extreme delicacy of the instruments that must be used in work of this kind renders them especially susceptible to magnetic disturb- ances. Many observations are thus made valueless by a change in the zero point of the galvanometer during the three or four minutes required for the needle to come to rest. Only a few seconds are required, however, for the first throw of the needle, and the change in zero point during this time would scarcely ever be sufficient to cause an appreciable error. The use of the first throw im place of the final deflection may therefore lead to greater accuracy as well as to a saving of time... It will be observed that the: principle underlying this method of taking readings is not confined to the case of the thermopile, but is capable of quite wide application. The following are suggested as cases in which the method may be employed with especial advantage : (1) All ordinary measurements of radiant heat, when the conditions are such as to make the galvanometer unsteady, or when the saving of time is a consideration. (2) For purposes of demonstration in the lecture room. A number of experiments which are usually considered unavail- able for lecture demonstrations have been quickly and accu- rately performed in this way under conditions that would render the use of the ordinary method entirely out of the question. (3) For measurements of the heat from a variable source. The first throw of the needle will in this case give the amount of radiant energy at the very instant of exposing the pile. Hidden and Mackintosh—Polycrase of the Carolinas. 423 (4) For work with a bolometer or similar instrument, under the same conditions that apply in the case of the thermopile. (5) For the measurement of a constant or variable current, where it is desirable for any reason to take readings quickly. For example, the initial value of the current from a cell which is subject to rapid polarization may be determined by the first throw of the needle. Other applications of the method will doubtless suggest themselves. It is with the hope that a phenomenon which at first appears to be merely a matter of curiosity, may thus be made of practical value in the laboratory, that this note is presented. Art. LU.—Supplementary Notice on the Polycrase of North and South Carolina; by W. E. HippEN and J. B. MACKINTOSH. THE occurrence and composition of this mineral were partially announced by us in volume xxxix, pp. 302-306, of this Journal (June, 1890), and the localities have received no development of moment since that publication. The South Carolina locality is distant about four miles from Marietta, in Greenville County, and is situated otherwise as before described. As to the form of the mineral, we have some interesting features to add to our previous statements and we here subjoin two figures (1 and 2) representing the two types observed and a corrected list of occurring planes with the angles obtained by using a contact goniometer. The planes observed are as follows, those marked with an asterisk (*) are new: a (010, 7-7) d (103, 4-7)* y (133, 1-3) b (100, 7-7) u (O11, 1-%) z (233, 1-3)* ce (001, O)* s (021, 2-7) q (130, 7-3) Am. JouR. Sct —THIRD SerigEs, Vou. XLI, No. 245.—May, 1891. 28 424 Hidden and Mackintosh—Polycrase of the Carolinas, Angles (approx.) observed : DinS = tol bad = 1074° 5 br = Tis UAL 94° b« y 104° Zay 140° Gad 160° These angles closely agree with those recorded for polycrase in Dana’s System of Min., p. 528. Among the South Carolina crystals we observed several apparent twins, one was parallel to s (021, 2-2) and another seemingly parallel to d (103, 4-2). Among the North Carolina crystals one was found quite perfectly twinned parallel to wu (011, 1-2). Whenever one of the South Carolina crystals was | found terminated at both ends, it was discovered to be hemi- morphic in the occurrence of the planes ¢ (001, O) and d (108, 4-2) and invariably hemihedral as to the plane z (228, 1-8); these two features being new to the species. Figures 1 and 2 were, in several instances, combined in the same crystal; though no crystals were found that had both terminations perfect. Most of the specimens were fragmentary and no crystals or masses were found attached to a matrix. It seems that the one and a quarter kilograms received by us was obtained by washing after the manner of gold mining some kaolinized coarse granite and that this quantity represents nine-tenths of the total amount found at the Marietta, South Carolina, locality (not ten kilos [22 .Ibs.] as before stated). Concerning the Henderson county, North Carolina, locality nothing noteworthy has been found there recently. Our later attempts in the separation of the metallic acids have been somewhat more satisfactory and acting upon a suggestion made to us by Dr. F. A. Genth we made the initial fusion with potassium bi-sulphate (we had previously used the sodium salt). Our results have enabled us to positively identify this mineral as polycrase and to arrive at a very satisfactory formula for the species. ms, The corrected analyses of two varieties are as follows :— Henderson Co., N. C. Greenville Co., S. C. Oxygen ratio. Oxygen ratio. ObEOE Sse 19°435 se see 36°35 5:000 19372 ee oe 36:14 5:°000 GOs. ee IO ;Si se Pe eee SATIS Ds Dio 23:51 Sopa TL°27 9°858 Y20sz, ete OX “SSO eee ae 21:23+ 23°06 7 HeO. eee: 2°87 4:00 } 48°73 6°703 247 3°43 | 18] epee 13) ae eee 1947. 20-350) See PhO, eo as OATES ae 0:46:\l0.20 hare me eos = = Seek Sh oc eee BRS Se le 0-718 0°33 | CaO ese a Lb >. ie 0°68 bees UM fale BEG san 5°18 = SR BEoomeo OD 4°46 = 24°78 3°427 TInsol. _ 3 MesAN ES ca: as, 28 a 2 10 0:12 Sie ue eas i Beet cee! eae 101 98°16Z 97°96% * At. wt. = 112. + At. w't. = 114:1 Chemistry and Physics. 425 Inspection of the oxygen ratios shows that when reduced to the simplest terms the relation is, as follows, Cb,O,: TiO,: me: HO 1:251f: 2 there ‘beg in beth cases a ‘slight excess of water which undoubtedly does not enter into the composition of the mineral. The formula which we deduce for the species is therefore 3(Cb,O,, 5T10,) 102RO+H,0) or grouping H,O under the general head of RO we have the simple form Cb,O,, 5 TiO,, 10RO. It is evident that this is not merely an isomorphous mixture of a columbate and a titanate, but that we have a definite salt of a complex inorganic acid, a columbo-titanate properly so-called. It seems also that we are justified in regarding water as an essential constituent. The separation of the metallic acids is even yet not very satisfactory, as our titanic acid shows the presence of columbic acid, but we feei assured that the formula deduced will not be altered by the results of more exact separations. Regarding the yttria earths present in both varieties we would state that a concentrated solution of them exhibited little if any absorption spectrum and the ignited oxides were of a paler straw color than any we have yet met with, approaching nearly to whiteness in the Marietta mineral. Prof. Rowland has kindly examined the Sonth Carolina variety spectroscopically in its crude condition, and has identi- fied all the lines of its spectrum, except one or two, as belong- ing to IN bail eVtearthsSe, Ura hes Pb; Faint evidences also of Mn, Al, Neo, Di, La, Th(?) and Ce, with the lines of Nb very weak. ‘“ There was no Praseo, Di, Va. bes Th or Ge.” He adds that “he has not tried to identify other elements as all the portion of the spectrum examined [i. e. 2 feet out of 10] was satisfied by the above mentioned. The amount of thorium was too minute to be certain of. There was more scandium than in any other mineral he had ever studied spectrographi- eally, except xenotime (from North Carolina) and one excep- tional mass of samarskite.” The discovery, by Prof. Rowland, of the presence of scandium in this polycrase adds very materially to its interest. SCIENTIFIC INTELLIGENCE. I. CHEMISTRY AND PHysIcs. 1. On the Speed of Chemical Reactions in Jelly.—Since the liquid condition of substances is generally regarded as essential to the rapid and uniform progress of chemical changes, Rerorm- 426 Scientific Intelligence. ATSKY has considered it desirable to test the question whether in the case of slow reactions, the speed is influenced by the passage of the medium into the semi-solid state, like a jelly. For this purpose he selected the katalysis of methyl acetate by hydro- chloric acid. Two solutions were prepared: one containing 20 c. ec. half-normal hydrochloric acid, with 10 ¢. ¢. of water and one c.c. methyl acetate; the other 20 c. ¢. of the same acid, with 10 c.c. agar-agar solution of 1:25 per cent, and 1 ec. ¢. methyl acetate. These solutions were placed in separate vessels and the temperature regulated by a thermostat to 25°. The strength of the agar-agar solution was so regulated, that at 35° the mixture was completely liquid, while at 25° it was so solid that the vessel could be inverted withont showing more than traces of flowing. At the same time, the jelly had so little coherence that it could be drawn into a pipette with a somewhat large opening and could be so far divided by stirring with a glass rod as to permit of titration. Two parallel sets of experiments were made, the «. ¢. of baryta water required to neutralize the acid in one c. c. of the solution being noted at equal intervals for each solution. The numbers given in the paper show that in both cases the speed of the reaction is the same, within the errors of experiment. This result indeed might have been expected. The speed of chemical changes in homogeneous systems depends not on the greater or less speed of the final masses with regard to each other, but upon that of the molecular motion; so that it is a function not of the interior friction, but of the diffusion-coefficient. Since therefore it has been proved that the speed of diffusion in agar-jelly is the same as in pure water, it follows that the speed of chemical change cannot be materially altered by the presence of the jelly. Still it was important to establish this result by direct experi- ment.—Zeitschr. physikal. Chem., vii, 34, Jan., 1891. GF. B. 2. On the Direct-reading of Volumes in Vapor-density Deter- minations.—LUNGE and NEUBERG have applied the apparatus, contrived by the former chemist for the direct reading of gas volumes,* to the determination of vapor-densities. For this pur- pose they attach the Meyer bulb to the measuring tube in place of the gas evolution flask. After the vapor in the bulb has ex- pelled the corresponding volume of air, the pressure tube is raised until the level of the mercury in the reduction tube reaches the normal mark. Since under these conditions the gas-volume is also at the normal pressure and temperature, this volume may be directly read off. If this reading is in cubic centimeters, g grams of the substance give v cubic centimeters of vapor, and the density D=g/v. 0:001293. By this method the vapor density of benzene was determined as 2°66 — 2° 76, that of naphthalene 4:2, that of triphenyl-methane 8°24, and that of mercury 6°8. In all these cases except the first, the temperature of determination was below the boiling point of the substance; the value of mercury for example being obtained in the vapor of diphenyl at 254°, the * This Journal, III, xxxix, 396, May, 1890. Chemistry and Physics. 427 boiling point of mercury itself being 359.-—Ber. Berl. Chem. Ges., xxiv, 729, March, 1891. Gi ae Bi 3. On Hydrazoie Acid.—Further observations upon azoimide or hydrazoic acid N,H, have been published by Curtius in con- nection with RaDENHAUSEN. They have succeeded in isolating the anhydrous gas in the pure state and find that it is permanent only at temperatures above 37°. Below this even at the atmo- spheric pressure it condenses to a clear colorless mobile liquid, which is highly explosive, and which possesses the intolerable odor of the gas. The liquid is readily miscible with water or alcohol. On fractionating the concentrated aqueous solution four times, an acid was obtained containing over 90 per cent of N,H. From this the last traces of water were removed by means of fused calcium chloride. The anhydrous liquid thus obtained is found to boil at 37°. When suddenly heated, it explodes with extraordinary violence with a vivid blue flame. In a Torricellian vacuum it explodes spontaneously at the ordinary temperature; the explosion under these circumstances of only five centigrams being sufficient to pulverize the apparatus completely, driving the mercury in the form of dust into every corner of a large laboratory. On one occasion, about 0°7 gram suddenly exploded on removing the tube containing it from a freezing mixture in which it had been immersed. Every glass vessel in the Vicinity was completely shattered by the concussion and one of the authors was seriously injured. By determinations of its conduc- tivity, Ostwald finds this acid to be a little stronger than acetic acid. Moreover, the authors have not succeeded in effecting the change of the ammonium salt N ,NH, into an !someric substance, as suggested by Mendeléef. The ammonium salt itself crystallizes in fine large prisms, which grow continually smaller and finally disappear, by continuous sublimation.— ature, xlili, 378, Feb. 1891. e105 es 4. On the Production of Arabinose from Wheat bran.— STEIGER and ScHuLze have shown that, when wheat bran, freed from starch and albuminous matter, is boiled for several hours with a three per cent sulphurie¢ acid, the acid removed by barium carbonate, the solution filtered, evaporated and extracted with alcohol, there crystallizes out arabinose on evaporation of the alvohol. It is probably formed by the hydrolysis of metaraban, a constituent of the cell membrane which cannot be obtained pure but which gives a cherry-red color on warming with hydro- chloric acid and phloroglucinol.— Ber. Berl. Ohens, Ges., XXlll, 3110, October, 1890. G. F. B. 5. On distinguishing arsenic from Agittnond —DENIGES pro- poses to distinguish between the deposits of arsenic and antimony by the fact that if the stain obtained by Marsh’s test is placed in a porcelain capsule and heated with a few drops of pure nitric acid, and then treated with a small quantity of ammonium molyb- date dissolved in nitric acid, the antimony deposit gives no pre- cipitate while arsenic forms arseno-molybdie acid which separates 428 Scientific Intelligence. as a yellow precipitate. This under the microscope is seen to consist of stellate crystals with triangular arms, generally six, arranged in rectangular planes along the axes of a cube, and which polarize light. The author regards this as the most sen- sitive and distinctive test for arsenic. He prepares the ammonium molybdate solution by dissolving ten grams of this salt and 25 grams of ammonium nitrate in 100 c¢.c. of warm water. After cooling, 100 c. c. of pure nitric acid of sp. gr. 1°20 are added drop by drop with active stirring. Then the liquid is heated on the water bath for ten minutes, allowed to cool and after 48 hours, filtered.— C. &., exi, 824; J. Chem. Soc., 1x, 364, March, 1891. G. F. B. 6. On Priestley’s Hudiometric method.—The method adopted by Priestley for measuring the oxygen in the air by mixing a measured volume of nitrogen dioxide with it and noting the diminution of volume, has been condemned as inaccurate. WaANK- LYN has investigated the matter and concludes that the inaccuracy is due to the oxygen present in the water through which the gas is made to pass. This source of inaccuracy may be avoided by using a Hempel apparatus and measuring the air in the gas burette and then passing it into an absorption pipette contain- ing water. The nitrogen dioxide is introduced into the gas burette and measured and then (without bubbling through water) passed into the air in the absorption pipette. After the nitric tetroxide formed has been absorbed by the water in the absorp- tion pipette the gas is passed back into the gas pipette and is gal J. Chem. Soc., 1x, 362, March, 1891. &@. F. B. 7. On Crystalline Liquids.—Attention has been drawn by Lrumany to the fact that the optical behavior of certain liquids is such as to suggest a crystalline structure in them. Chemically however these liquids are homogeneous and their anisotropic character is not due to external stress. He now raises the ques- tion whether liquids which are isotropic are non-crystalline, or whether they are crystalline and isometric. In view of the free miscibility of liquids, however, he concludes that they are non- crystalline, since were this not the case they could mix only with isomorphous substances. This conclusion the author supports by experiments on the miscibility of crystalline liquids with each other and with solid crystals. Liquid crystals, when heated between cover glasses to a point slightly above that at which they pass into ordinary liquids, retain on cooling the original direction of their optic axes owing probably to condensation and consequent higher melting point of a layer on the surface of the olass, Isomorphous liquid crystals exhibit the phenomena of diffusion and hence the capability of solids to form mixed crystals - appears to correspond exactly with the process of mixing or dif fusion in liquids.— Ann. Phys. Chem., xli, 525.—-J. Chem. Soe., lx, 249, March, 1891. 8. On the Refractive indices of Water.—Brtu.t has measured the refractive indices of water for light of certain wave-lengths Chemistry and Physies. 429 not hitherto employed. These are the double red line of potas- sium, of wave-lengths 0°770 and 0°767 4, and the od line of hydro- gen, coinciding with the Fraunhofer line /, and of wave-length 0°4101 uw. In order to obtain the necessary brightness, the potas- sium bead was made of a mixture of potassium perchlorate and chloride ; and it was placed at the point of the reduction-cone of the Bunsen flame. For the H; line, end-on spectrum tubes were employed, the light being bright enough to show even H, Be- sides these lines, those of lithium, sodium and thallium were also used, and the lines Hy Hg and H, in addition. A Fuess spectro- meter reading to thirty seconds was employed, the minimum- deviation adjustment being secured for each kind of light and for each temperature. The following are the results obtained, each value being the mean of a series of measurements which the author believes correct to the fourth decimal place at least : Temp. K Li Ha Na Tl Hg Hy Hy Tee a2eco. 1css088m icosh20) W33300 | f:33493" 1733720 91634045 1534239 2a tees 289k 133000) 13309 9133280) 133468) 1733692) 1:34016 SS rosso Deel SI802- le S804 1s io tok TTBS 2216) an ISS C0 (ae aed ey ma ee eee AE") ces a ear ae Ree ML SOOO louse ey. ps TES SO JOM tacts ie eae ee Hic Omemles tes wleoS0SS) acs 0 0 See TG AO eran These results are compared with those obtained by v. d. Wil- ligen, Landolt, Willner and Ritihlmann for all the lines except K, and H, and show a close accordance.— Ber. Berl. Chem. Ges., xxiv, 644, Mch. 1871. G. F. B. 9. Genesis of the Hlements.—Professor WiLL1AM CrooKEs closes a most interesting address before the Institution of Electri- cal Engineers on the subject ‘“ Electricity in transitu: from plenum to vacuum,” with the following remarks on the genesis of the elements :— It is now generally acknowledged that there are several ranks in the elemental hierarchy, and that besides the well-defined groups of chemical elements, there are underlying sub-groups. To these sub-groups has been given the name of “ meta-elements.” The original genesis of atoms assumes the action of two forms of energy working in time and space—one operating uniformly in accordance with a continuous fall of temperature, and the other having periodic cycles of ebb and swell, and intimately connected with the energy of electricity. The centre of this creative force in its journey through space scattered seeds, or sub-atoms, that ultimately coalesced into the groupings known as chemical ele- ments. At this genetic stage the new-born particles vibrating in all directions and with all velocities, the faster-moving ones would still overtake the laggards, the slower would obstruct the quicker, and we should have groups formed in different parts of space. The constituents of each group whose form of energy governing atomic weight was not in accord with the mean rate of the bulk of the components of that group, would work to the outside and be thrown off to find other groups with which they 430 Scientific Intelligence. were more in harmony. In time a condition of stability would be established, and we should have our present series of chemical elements, each with a definite atomic weight—definite on account of its being the average weight of an enormous number of sub- atoms, or meta-elements, each very near to the mean. The atomic weight of mercury, for instance, is called 200, but the atom of mercury, as we know it, is assumed to be made up of an enormous number of sub atoms, each of which may vary slightly round the mean number 200 as a centre. We are sometimes asked why, if the elements have been evolved, we never see one of them transformed, or in process of transformation, into another. The question is as futile as the cavil that in the organic world we never see a horse metamor- phosed into a cow. Before copper, e. g., can be transmuted into gold, it would have to be carried back to a simpler and more primitive state of matter, and then, so to speak, shunted on to the track which leads to gold. This atomic scheme postulates a to-and-fro motion of a form of energy governing the electrical state of the atom. It is found that those elements generated as they approach the central position are electro-positive, and those on the retreat from this position are electro-negative. Moreover, the degree of positive- ness or negativeness depends on the distance of the element from the central line; hence, calling the atom in the mean position electrically neutral, those sub-atoms which are on one side of the mean will be charged with positive electricity, and those on the other side of the mean position will be charged with negative electricity, the whole atom being neutral. This is not a mere hypothesis, but may take the rank of a theory. It has been experimentally verified as far as possible with so baffling anenigma. lLong-continued research in the laboratory has shown that in matter which has responded to every test of an element, there are minute shades of difference which have admitted of selection and resolution into meta-elements, having exactly the properties required by theory. The earth yttria, which has been of such value in these electrical researches as a test of negatively excited atoms, is of no less interest in chemistry, having been the first body in which the existence of this sub- group of meta-elements was demonstrated. 10. Geschichte der Photographie ; by OC. ScHIENDL. pp. 380, small 4to, Vienna (Hartleben). ihe author commences with a brief review of what few observations were made by the ancients upon the action of light, which seem to have amounted to very little, and then passes to the early beginnings of photography in modern times. These chapters are full of interest. From his in- vestigations the author concludes that the first actual image pro- duced by ight was obtained by J. H. Schulze in 1727 who ob- served that a mixture of nitric acid, silver nitrate and lime in ex- cess produced a compound which darkened in sunlight but that the portion under the piece of cord, which he tied around the flask Chemistry and Physics. 431 in which the matter was contained, remained white. Only at long intervals were further steps made. Thirty years later Beccaria made the observation that the coloring of silver chloride was due to the action of light and not as previously supposed, to that of the air. In weighing the relative claims of Nicéphore Niépce and of Daguerre to the actual discovery of photography the author is disposed to believe that the former has received too little and the latter more than his due share of the honor. The discoveries which rapidly followed after this are next described and the author has evidently devoted much care and thought to the pre- sentation as well of the theoretical views as of the practical processes which have been brought forward up to the present time. The book seems to deserve a translation into English. M. c. L. 11. Die Elektrischen Verbrauchsmesser von Et1iENNE DE Fopor. 219 pp. 12mo. Vienna, 1891.—Electro-technical Library, vol. xlii (A. Hartleben). The electro-technical library, the earlier issues of which have been noticed in the Journal, has grown to upwards of 40 volumes covering a wide range of topics. It would be difficult to find elsewhere so much direct practical information on subjects dealing with the technical application of Electricity, as is compressed into these little volumes. The present issue takes up the subject of Electric meters and with great fullness gives the many forms that have been devised, from the earliest kinds first described to those now found most practi- cally useful. The forms described are so numerous that the account of each is brief, but the abundance of illustrations adds much to the completeness of the treatment. 12. Das Totalreflectometer und das Refractometer fiir Chemiker, ihrer Verwendung in der Krystalloptik und zur Untersuchung der Lichtbrechung von Fliissigkeiten von Dr. C. Putrricu. 144 pp. 8vo, with 4 plates. Leipzig, 1890 (Wm. Engelmann).—This volume contains a thorough discussion of the theory and practi- cal use of the new form of totalreflectometer, first described by the author in 1887 (Wied. Ann., vol. xxx, p. 193). The method consists, in a word, in determining the critical angle for the light- ray which has passed from below into a glass cylinder and suf- fered total reflection from the surface of the substance under examination placed upon the plane surface of the cylinder. The required refractive index is given by the equation m = 4/N? — sin?7 where N is the index for the glass and ¢ the angle of emergence. By using different kinds of glass from N = 1: 95 to 1: 60, refrac- tive indices from 1°675 to 1:249 may be determined. The ‘method is easy of application and, as shown by measurements by the author and others by Miihlheims, capable of giving accurate re- sults. A special chapter describes the modification of the instru- ment as designed for the use of chemists in the measurement of refractive indices of solutions. 18. Appleton’s School Physics ; embracing the results of the most recent researches in the several departments of Natural 432 Scientific Intelligence. Philosophy by J. D. QuackENBos (literary editor), A. M. Mayer, F. E. Nrpuer, 8. W. Horman, F. B. Crocker. 544 pp. New York, Cincinnati, Chicago, (Amer. Book Co.—D. Appleton Co.’s Press). It is satisfactory to receive an elementary work on Physics which, like the one in hand, is fresh and new throughout, and not an abridged reproduction of matter and illustrations which have done duty for many years. The limitations of a book for early students in a subject so large and profound are severe, and it would not be difficult here to find points to criticize, but the manner in which the several editors have done their work is deserving of decided commendation. The simplicity of the treatment and the practical character of the illustrations make the book particularly well suited for the class of students for which it is written; it should have a wide sphere of useful- ness. 14. Handworterbuch der Chemiker. By Dr. Cart SCHAEDLER. 12mo, pp. vi, 162. Berlin, 1891 (Friedlander).—A series of brief biographical sketches of eminent chemists and physicists. The Americans noticed are the two Sillimans and Remsen. 15. Bibliotheca Polytechnica: a Directory of Technical Litera- ture. ie V. SZCZEPANSLI. 12mo, pp. 80. New York, 1890. (Int. News Co.).—A classified catalogue of technical books and Ses published in America and Europe. II. GroLtoGy AND NATURAL HISTORY. 1. On the Rock-fracture at the Combined Locks Mill, Apple- ton, Wisconsin; by FRank CraMER. (Communicated. )—It was impossible, after the upheaval of a part of the pulp-mill at the Combined Locks, in September, 1889,* to get direct evidence of movement in the underlying rock. During the past summer, the water was pumped out of the tail-race for the purpose of deepen- ing the latter, and this gave an opportunity to examine the rock layer on which the mill rests. It will perhaps be well to describe the fracture in the rock under the mill, to show how accurately the cause was registered in the effects. What the extent of the disturbance was just outside of the cement pier and above the dam, cannot be known. But inside, under the mill, the crack in the rock begins directly under the big crack in the pier and runs under the piers supporting the sixth, seventh and eighth machines and close to those supporting the third, fourth, fifth, ninth and tenth machines. It passes out under the sixth and seventh windows and ends in the quarry in the tail-race just below the mill. The rock is lifted into a low ridge which gradually dies away toward the quarry. The effects of the compression are most marked near the big pier. Here the rock on one side of the fracture is lifted nearly a foot, while on the other side it has fallen back nearly into its ori- ginal position, leaving a fault of eight inches. Along the line * See this Journal, xxxix, 220, 1890. Geology and Natural History. 433 of fracture the rock is broken into pieces varying in size from a few square inches to several square yards. The fault dis- appears where the erack passes out from under the mill; and here the splintering is confined to a depth of two or three inches and a width of four or five. The chips vary in size from half an inch to two or three inches square, and many of them are scarcely thicker than a sheet of paper. Beyond this the ridge, the fault and the crushed rock disappear and there is nothing to indicate a disturbance, except a clean fracture, which ends in the quarry. There have been observed, in this region, two or three other cases of fracture which will throw light in the search for the cause of the fracture at the Combined Locks. Between the last two locks in the government canal at Kaukauna, about sixteen inches of the upper rock layers had been removed, leaving a layer three and a half inches thick at the surface in the bottom of the canal. Be- fore navigation opened last spring the canal bed was examined, and this upper layer was found fractured and raised into a ridge for a distance of about twenty-five feet along a line of drill-holes that had passed through it. It was proved beyond a doubt by the conditions observed on the spot and by the testimony of men who helped remove the rock in the canal, that the ridge was not formed until at least one season after the canal had been finished and in use. The one layer was raised sixteen inches, leaving a hollow underneath. The fracture passed along the line of the drill-holes, and formed the axis of the ridge. Its direction was N. 20° E. parallel with that of the canal and the river. : Only a few hundred feet away from the canal another break in the rock occurred in June, 1889. At this point the high clay bluff bends away from the river, leaving a large flat, but little above the river level, and with the rock almost bare of soil. On this flat, at the south end of private claim 33, there was a quarry four and a half feet deep. A six-inch layer of limestone formed the floor of the quarry, at one end of which a hole seventeen inches deep had been blasted as a start for the next “level.” The water was pumped out of the quarry in June; and after four or five days of warm weather, while some men were working just behind a knoll, they heard a noise which they described as being like that of exploding dynamite. The layer forming the floor of the quarry was fractured; the crack started from the hole at one end and ran down the middle of the quarry for some distance, and then bifurcated, the branches running to the two corners at the south end. The rock was lifted into a ridge sixteen inches high, and in some places split into thin plates. ‘The fracture ran at right angles to the river and the high clay bank. A paper mill has recently been built at Kimberly, three miles down the river from Appleton, and three miles up the river from the Combined Locks. A large quarry four feet deep was opened in the river bed below the government dam. While Mr. Charles Riggs, the contractor, and the men at work in the quarry were 434 Serentific Intelligence. eating dinner one bright day, they heard a snapping noise. The rock in the bed of the quarry was ripping. The disturbance started at the lower end, traveled up the river, and ended in a wheel-pit fifty feet square and four feet deep. It required sev- eral seconds to make the trip, and shook up the ‘‘ quarry chips” that covered the bottom of the quarry to the depth of about a foot. Later, when the covering of the chips were removed and the quarry cut deeper, it was found that the first eight inches of the rock was broken by a clean fracture, but below that, was much crushed. How far down the crushed condition extended is not known; the quarry was made two feet deeper, and crushed rock was still in sight. The directicn of the crack was N. 45° E. When the several cases of fracture described above, all of which occurred in the compact Galena limestone of the Fox River valley, are considered together, it becomes clear that the weight of the clay plain had nothing to do with their production, for some of them run parallel with the river and the high clay banks, and others make high angles with them. And, further, there is no parallelism among the cracks themselves. The times of the year and other conditions under which the disturbances occurred make it impossible to assign a common local cause for them, and it is as difficult to point out a separate cause for each. It seems evident that the cause of the fractures is a condition of the rock itself; and that in this region it is suffering compression in all directions. The local character of the disturbances is well illus- trated by the fracture at the Combined Locks, where at one end there were crushing, uplifting and faulting, and less than 125 feet away there is nothing but a simple fracture. The direction of fracture seems to be determined, not so much by preponderance of pressure in a particular direction as by the artificial relief given in each case. The local conditions, perhaps even including barometric disturbances, seem to furnish nothing but the occa- sions for the action of the general cause. The facts are in har- mony with Gilbert’s theory that the superficial strata have ex- panded in consequence of their rise in temperature since the close of the glacial period. But more data are needed for a demonstra- tion. Lawrence University, Appleton, Wis., Jan. 10, 1891. 2. Bulletin of the Geological Society of America, Vol. I1.— The papers read at the December meeting, already published, include the following: C. L. Herrick, on the Cuyahoga Shale, and the problem of the Waverly; G. F. Becker, on the structure of a portion of the Sierra Nevada; Ed. V. D’Invilliers, on the Navassa phosphate deposits; A. Winchell, a last word with the Huronian ; C. W. Hayes, on the overthrust faults of the Southern Appalachians; Robert Bell, the nickel and copper deposits of Sud- bury District, Canada, with an appendix on the silicified glass- breccia, by G. H. Williams; Geiger and Keith, on the strucure of the Blue ridge near Harper’s Ferry; G. M. Dawson, Geological structure of the Selkirk range; G. F. Becker, on Antiquities Geology and Natural History. — 435 under Tuolumne Table Mountain, Cal., and notes on the early Cre- taceous of California and Oregon; R. Pumpelly, on the relation of Secular rock-disintegration to certain transitional crystal- line Schists; A. Winslow, on the geotectonic and physiographic geology of Western Arkansas; W. Upham, on Glacial lakes in Canada; C. R. Keyes, stratigraphy of the Carboniferous in Cen- tral lowa; E. Brainerd, on the Chazy in Champlain valley; G. H. Williams, on the petrography and structure of the Piedmont Plateau in Maryland, with a supplement by C. R. Keyes; J. Le Conte, on the Tertiary and Post-tertiary changes of the Atlantic and Pacific Coasts; J. EK. Wolff, on the Lower Cambrian age of the Stockbridge limestone ; H. D. Campbell and W. G. Brown, composition of Mesozoic igneous Rocks of Virginia; W. H. Weed, on the Cinnabar deposits and Bozeman coal fields of Mon- tana; cise Turner, on the Geology of Mount Diablo, Cal., with a supplement on the ‘chemistry of the rocks by W. H. Melville. 3. Cambrian fossils in the Stockbridge limestone of Vermont. —J. EK. Wo.rr, in his paper in vol. 11 of the Bulletin of the Geological Society of America (page 331), mentions the very important discovery of Lower Cambrian fossils in the great central limestone belt of Vermont, at several localities in the vicinity of Rutland. The fossils are a species of Autorgina, and a Salterelia, much like S. currata of the Olenellus Cambrian of North Attleboro, Mass. The limestone belt has, on its east side, with conformable bedding, the Green Mountain quartzyte, which Walcott proved, by the discovery of fossils, to be Lower Cam- brian. West of the Limestone belt and dipping beneath it there is a second quartzite, that of Pine Hill, which also is referred to the Olenellus Cambrian. West of this there is a Center Rutland belt of limestone which was proved by fossils to be of Lower Silurian age, like that of the West Rutland limestone. Dr. Foerste was associated with Mr. Wolff in the discoveries. 4, Geological Survey of Kentucky.—This survey under John R. Procter, Director, has recently issued a report on the Geology of Clinton County, by R. H. Loughridge, M.D., and another on Whitley County and a part of Pulaski, by A. R. ‘Crandall, assist- ant. Each is illustrated by a colored geological map, and the latter also by several plates. 5. Geological Survey of Missouri.—Bulletin No. 4 of this Sur- vey contains descriptions of a large number of new species of Crinoids, from the Subearboniferous beds of Missouri, by S. A. MiLueER, with figures illustrating them on four plates. A Bien- nial report by Mr. Winslow, the State Geologist, has recently been issued, which gives a sketch of former geological surveys in Missouri, and an account of the work now going forward. 6. Geological Survey of Arkansas.—J. C ). BRANN ER, State Geol- ogist. The annual report for 1889, vol. ii, covering 283 pages, 1s devoted to an excellent detailed account of the ceological struc- ture and the resources of Crowley’s Ridge, by “R. Exrsworta CALL. Erowley's Ridge, the only marked prominence in the 436 Screntifie Intelligence. country between Little Rock and Memphis, rises usually over a hundred feet above the level of the country on either side of it. A colored map accompanies the report. : 7. Geological Survey of Texas,—The annual appropriation for the Geological Survey of Texas, made by the Legislature just adjourned, is $35,000, exclusive of printing. Appropriations were also made for testing the lignites, for the publication of an accurate map of the State, and for the erection of a laboratory building at the University of Texas, which will contain a suite of rooms for the chemical department of the Survey. 8. Geological Survey of Alabama. — Professor Eugene A. Smith informs the editors that the last legislature of Alabama placed the annual appropriation for the geological survey at $7500, and made it continuing, i.e. till otherwise provided by law. This puts the survey on a very desirable footing as to per- manence as there will be no effort to bring the work to a close so long as there is anything to report upon, which in the case of such a state as Alabama, will be a long while. The printing, engray- ing, ete., are paid for out of another fund, which leaves the whole amount of the appropriation to be devoted to the defraying of the general expenses of the survey. The first work to be under- taken will be the detailed mapping of the Warrior and Coosa Coal Fields. University Ala., Feb. 23, 1891. 9. A Bibliography of Paleozoic Crustacea from 1698 to 1889, including a list of North American species and a systematic arrangement of genera; by ANrHony W. VocpEs. 1890. 117 pp. (U. 8. Geological Survey, Bulletin 63).—This work, which has been long announced, will meet a warm welcome from students of fossil Crustacea. The bibliography (Part I), extending from pp. 13-78, is a compilation noteworthy for its few omissions, and is unquestionably the most exhaustive analysis of the literature of these fossils yet produced. The citations consist of the titles in full, with a summary of the genera discussed, and frequent critical notes upon genera or species. An excellent feature of these citations is the more extended notice given to works of early date and those accessible with difficulty. If future editions would give, even at the necessity of considerable increase in size, the names of species as well as genera discussed in each work cited, it will prove a valuable addition. Species are the important units; generic values are constantly varying with the increase of knowledge. Part II is a systematic catalogue of the North American Paleozoic Trilobita, preceded by a brief synoptical table of genera and Part III is a similar list of the non-trilobitic species. In these catalogues Captain Vogdes has kept himself singularly free from the expression of personal convictions of generic and specific values, preferring to accept the latest results of reliable investigation as standards. In this respect the cata- logue possesses a value not shared by previous attempts in this direction which have been carried on without special familiarity Geology and Natural History. 437 with these fossils. The author’s convictions are however often apparent, even when not enforced. For example, he adopts the term Zrinucleus, though expressing the opinion that Dr. Green’s Cryptolithus is entitled to acceptance; again the genus Acidaspis is retained in its broad and current usage, though Captain Vogdes himself has at an earlier date warmly and justly espoused the precedence of Warder’s term, Ceratocephala ; in these and other instances evincing his consideration for the convenience of those who will make the most use of the work. But two new generic names are proposed, Lloydia (in honor of Edward Lihwyd “the first author on Trilobites”) for the species Bathyurus bituberculatus Billings, and Strigocaris, in place of Solenocaris Meek, a preoccupied term. The catalogue of non-trilobitic genera is preceded by a scheme of classification which is open to objec- tion in some respects. The author does not choose to recognize Packard’s order Phyllocarida, but divides the Phyllopoda into the Ceratiocaride, Discinocaride and Rhinocaride and in the last family are placed Astheria, Leata and Schizodiscus (perhaps the only genuine phyllopods in the list) as well as the genus. Mesothyra, which belongs to the distinct family, Pinacaride. The entire work is unfortunately abundant in typographical errors, few, however that need cause serious annoyance. Some of these have already been corrected in a supplement issued by the author privately, and it may be expected that others will be eliminated in the future editions which, it is hoped, so valuable a catalogue will attain. Yo in 10. On the Organization of the Fossil Plants of the Coal-Meas- ures; by W. ©. Witttamson. Pt. XVII. Phil. Trans. Roy, Soc. London, vol. 181. 1890, B, pp. 89-106, pl. XII-XV.—Part XVII of this series of valuable memoirs is important for the evi- dence which it contains of the discovery of an exogenous devel- opment among the Carboniferous ferns. The anticipation ex- pressed by the author in Part IV that Dictyoxylon (Lyginoden- dron) Oldhamium, there described as belonging to Paleozoic Proto-gymnosperms might be identical with the petioles described, at the same time, as Edraxylon, and later (Pt. VI) as Rachiop- terds aspera, 18 now confirmed, and the two are conclusively proved to be trunk and petiole of the same plant. The origin of the tracheal bundles of the petiole in the middle cortex of the trunk and the formation of the medulla in the center are described with the author’s customary accuracy and minuteness of detail. As the medulla expands during the growth of the petiole, there is a corresponding increase in the number of vascular laminz, the inner extremities of which, though commencing their growth at different periods of life, all start from the medullary border of the vascular zone and extend to the periphery. The number of these laminze were observed to vary from 44 ina small specimen, in which the medulla was present, to 1120, similarly arranged, in a large one. Not only has Prof. Williamson examined many speci- mens showing the transition stages between the two types, but 438 Scientific Intelligence. his studies include specimens in which stem and petiole are or- ganically united, thus rendering more conclusive the proof that Lyginodendron Oldhanvium is a true fern, probably belonging to the Sphenopterids, and that the stems of some, at least, of the Carboniferous ferns “developed their xylene or vascular structure exogenously through the instrumentality of a meristemic zone of the innermost cortex, which practically must be regarded as a cambium layer.” D. W. 11. Catalogue of the Fossil Cephalopoda in the British Museum, Part IT; by Arruur H. Foorp.—Although nominally a cata- logue, this work possesses the nature of a monograph, and is a positive contribution to the literature of the subject. A full bibliographical notice is given of each genus and species, together with detailed descriptions of the principal characters. The pres- ent volume inciudes the families Lituitide, Trochoceratide, and Nautilide. The text is enriched with numerous wood-cuts drawn by the author. C: HE. B. 12. Mineralogical notes, by W. EK. Hippen and J. B. Macgintosu. (Communicated). Awerlite.—The lemon-yellow variety found on Price’s Land in Henderson County, N. C., has proved to contain more P,O, and correspondingly less SiO, than that from the Freeman Zircon Mine, three miles northeasterly in the same county. The density varies between 4:051 and 4:075. The ratio of P,O,+Si0,: H,O is the same as is demanded by the formula deduced from the former analyses. It is to be noted that the density decreases as the percentage of phosphoric acid increases. Among the crystals we have observed twins parallel to 1-7, as in zircon, rutile and cassiterite. The analysis has given : Molecular Ratio. BOR 8°58 X zis 262 ee SiO, 6.80, St Oe 028 \aarea as = ThO, [7216]Xggh5 553 Bs 2 FeO ee igs (2 ee H,O 1064 X 4 13199 () ape ule oe 6 100°00 The thoria was tested and found to be quite pure but was unfortunately lost before it could be weighed. The percentage above given is determined by difference. The above analysis confirms the formula previously assigned by us to this mineral (see this Jour., Dec. 1888, p. 462) i. e.,—ThO,, 142.6 2H,O or a thorite (orangite) in which part of the silica is replaced by its equivalent in phosphoric acid, when 3S8i0,=1P,0,. The P,O, tends to be in excess. 3 Sulphohalite [Na,(?SO,, +Cl)|.—A careful examination of the few crystals available has proved an apparent tendency to hemihe- drism, the octahedral faces being present only on the alternate trihedral solid angles of the dodecahedron. ‘This, if confirmed, Geology and Natural History. 439 would make the species tetrahedral like boracite, but this we cannot however assert positively on account of the present rarity of the mineral. Besides these faces of the octahedron (or tetrahedron) we have also observed the cube modifying the rhombic-dodecahe- dron. One very perfect crystal contained an irregular cavity full of a liquid in which was a moving bubble of air (or gas.) It also showed, by transmitted light, numerous lines of growth parallel to all the planes. On the composition of the fayalite from Cheyenne Mt., Colo- rado.*—This mineral has the high specific gravity of 4°35, shows cleavage, (imperfect) at right angles in two directions, is fusible and gelantinizes with acids. It occurred in this instance as a mass weighing nearly ten pounds and was quite abundant in the vicinity in the granite. Analysis leaves no doubt as to its nature. The results were: if 2. SiO, 27°30 27.66 FeO 5°83 65°794 MnO pani 4°17 CaO ls 0°47 98°24 The iron may be present in both the ferrous and ferric state but this point was not determined, or the reasons for the loss ascertained. 13. Mineralogical Notes; by W. E. HippEy, (communicated.) —Remurkable discovery of Bastnaesite and Tysonite.—In the summer of 1889, Mr. J. G. Hiestand, of Manitou Springs, Colorado, brought to my attention and sent samples of a new discovery of bastnaesite and tysonite, which he had made in the Pike’s Peak region, at no very great distance from Manitou. He reports that the total quantity found weighed over six kilograms and was originally all included in one great group or mass. Hexagonal tabular crystals, somewhat modified, nearly two inches across, of a clear deep brown color, made up the exterior layers of the larger fragments while the interior and greater portion was com- posed of the wax-yellow unaltered tysonite, in parts perfectly transparent. The specific gravity of several fragments was found to be only 6.007. For novelty’s sake a gem was cut that weighed two-thirds of a gram, but it did not have very much brilliancy. Some sections were made for optical examination and have been sent to Prof. Penfield for that purpose. A white mineral of an earthy nature and seemingly a product of alteration occurs in the bastnaesite and tysonite in large patches. Its specific gravity = 4:145. It lost 21°02 per cent after being strongly ignited and was then wholly soluble in HNO, making a deep red solution, (Ce). It may prove to be a mixture of bastnaesite with lanthanite. * See this Journal, March, 1885, p. 250. Am. Jour. Sci.—THirD SERIES, Vou. XLI, No. 246.—May, 1891. 29 440 Scientific Intelligence. Four new localities of FKergusonite.—Along with the orthite found near Amelia Court House, Virginia, I have discovered a few small crystals of fergusonite implanted upon it at right angles and projecting into the feldspar matrix to a depth, in some instances of 18 to 20™". The prisms were square with very dull gray surfaces, but were brilliant resinous on a fractured, surface. The terminations were obscure but traces of acute octa- hedra were noticed. Sp. grav. varied from 5° to 56. No analy- sis was attempted. . Witb the three hundred or more pounds of zircon mined by the writer in the near vicinity of Storeville, Anderson County, South Carolina, several crystals of a highly hydrated fergusonite have been found, some of which might more properly be termed an “yttro-gummite.” Corundum, garnet and columbite were also observed to exist quite commonly in the region. From near Spruce Pine, Mitchell County, North Caraline I have received several ounces of very fair crystals of fergusonite exhibiting externally various stages of alteration. It is said to have been found in the dump heaps of the Grassy Creek Mica Mine. As a contact association I have found allanite and cyrto- lite. The basal plane was prominent. One crystal weighed over twenty grams. Its behavior upon ignition was very characteristic and in all respects similar to the Texas mineral. In the early part of last year I observed this species as a tant frequent occurrence in the gold placers of the mines near Golden P. O., Rutherford County, N. Carolina; with such associates as xenotime, malacon, monazite, rutile, ete. On the “Orangite” from Landbé, Norway.--A partial ex- amination of this mineral, made on several grams of transparent resin-yellow massive material, has proved it to belong to the variety of thorite called wranothorite, like the mineral described by Collier and the Norwegian specimens later analyzed by Lindstr6ém and by Nordenskidld, and referred to uranothorite by Brégger. Its specific gravity = 4:322. It lost upon ignition (H,O) 11:97 pr. ct. and contained 18°50 pr. ct. SiO,; 52°53 pr. ct. ThO,; 9:00 pr. ct..UO,; 1°32 pr. ct. PbO and small amounts of lime and iron. Little if any of the cerium or yttrium earths are present, other ingredients were not looked after. It crushes into a creamy white powder which becomes dull green after strong ignition. A translucent red-brown variety, or partial alteration, has Sp. gr. = 4°303. An opaque earthy brown mineral having a black, pitchy look- ing core has been sent out from the same locality under the name of “thorite,’ but its low density (4:2) and the abundance of water, uranium and lead present, lead me to believe that it is only an impure variety of uranothorite. I have worked up over one kilogram of it and found it to contain about 45 per cent of thoria and 1 per cent of yttria earths. 14. Tenth Annual Report of the State Mineralogist of Cali- fornia for the year ending December 1, 1890. 983 pp. Sacra- Geology and Natural History. 441 mento, 1890.—The tenth Mineralogical Report of California, issued by Wm. Irelan, Jr., State Mineralogist, is a weighty vol- ume of ‘ae 1000 pages, “illustrated by many plates, maps and profile sections, and accompanied by a large geological and min- eralogical nae of the State on a scale of 12 miles to the inch. Detailed accounts are given of the mining operations in the several counties ; these ‘chapters are contributed by a number of different observers, including W. A. Goodyear, H. DeGroot, E. B. Preston, J. B. Hobson, M. Angell, W. L. Watts and others. The colored geological map mentioned is compiled from the twenty-five atlas sheets by the State Engineering Department which are on a scale of 4 miles to the inch. 15. Allgemeine Chemische Mineralogie von Dr. C. Dor ttzr. 277 pp. Svo. Leipzig, 1890 (Wm. Engelmann).—The fact that the author of this work has already made many important con- tributions to the subject of mineral chemistry both on the ana- lytical and synthetic sides gives us a right to expect a very clear and thorough presentation of the subject from his pen and in this he has not disappointed us. The successive chapters are devoted to the general chemical relations of mineral compounds, with a discussion of isomorphism, isogonism, etc. ; chemical analysis both in the wet and dry way; mineral synthesis; the alteration of minerals and their formation in nature, and finally a summary of all prominent mineral species with a statement of their compo- sition.. Of these various topics, we turn with most interest to the chapters which give an excellent summary of the present state of knowledge of artificial minerals, a subject which has been rapidly developed during the past two decades and one in which the author’s contributions are not inferior to those of any other German mineralogist. 16. Index der Krystaliformen der Mineralien, von Dr. Victor GoLpscumipr.—The announcement of the publication numbers 4 and 5, of volume iii, made in the March number, is quickly fol- lowed by the appearance of number 6, including the species from Xanthokon to Zunyite. This concludes the work with the exception of a supplementary number which is to be devoted to errata, etc. 17. Gray's Manual of Botany ; reprint of the sixth edition, edited by Dr. SeRENo Watson and Prof. J. M. Covuntrr, 1891. —In the revision of Gray’s Manual which appeared about a year ago, the editors earnestly solicited information of any additions or corrections which might appear necessary. In generous re- sponse to this request a number of botanists in different parts of the country have reported such additional details or alterations as, from their personal observation, they judged desirable. In the second issue of the sixth edition, which has recently been put upon the market, and to which we take pleasure in calling atten- tion, these additional details have received due recognition. A number of minor alterations have been made in the plates of the text, and are thus scattered through the work. Such changes, however, have naturally been limited ; ; and the chief new feature 449 Scientific Intelligence. of the reprint is a supplement of four pages, containing over a hundred additions and corrections. Atmong these changes, those very naturally predominate which extend the geographical range of species and varieties. T'wo genera, Franseria and Paulownia, and some dozen species and varieties have been added, being chiefly introduced plants, which have escaped from cultivation within the limits of the Manual. As book-dealers still have a part of the first issue to dispose of, persons especially desiring the corrected reprint should be careful to secure copies containing the four pages 735a, b, c, and d. Be 18. Hypertrophie des lenticelles chez la pomme de terre et quel- ques autres plantes ; (Bull. soc. bot. de France, ser. II, tome xiii, pp. 48-50).—In this brief communication to the French botanical society H. Devaux gives an account of a remarkable modification in the development of lenticels when submerged in water. His experiments were chiefly made upon growing tubers of the potato. These he found were “ asphyxiated” if completely submerged, but would live and continue their development if only partially covered with water. In the latter case, however, the lenticels, which are rather numerous, underwent a peculiar modification, increasing considerably in size, becoming conical, and opening so that a loose tissue protrudes from within. The interesting feature in the description is that the loose tissue thus formed closely resembles that modification of cork which normally occurs in cer- . tain swamp plants, and which H. Schenk has called aerenchyma. It is a secondary tissue characterized by thin-walled cells but slightly attached to one auother and separated by very large intercellular spaces filled with air or other gases. As Dr. Schenk has shown, this tissue probably plays an important part in the aeration of submerged or partially submerged plants. The produc- tion of the same sort of tissue in the lenticels of the potato, as de- scribed by Devaux, appears therefore an especially interesting example of the power of adaptation, which a plant may exhibit when placed in unusual conditions of growth. B. L. RB. 19. The Nursery-Book, a complete Guide to the Multiplication and Pollination of Plants ; by Prof. L. H. Bairey. (New York, 1891, 16mo, 300 pp.)—In this neat little volume the author gives concise descriptions of the numerous forms of artificial reproduc- tion practically applied in the cultivation of plants. ‘The various methods of grafting, layering and propagation by division re- ceive their proper attention, and details of manipulation and appliances for work are illustrated by numerous wood-cuts. In an extended alphabetic list of cultivated plants the best methods of propagation to be employed in individual cases are enumerated, to- gether with valuable hints in regard to proper treatment. The closing chapter deals rather briefly with artificial pollination and hybridization. The whole work is a model of clearness and prac- tical simplicity which will make it a valuable aid alike to profes- sional nurserymen and to amateurs in plant-cuiture. B. L. R, Miscellaneous Intelligence. 443 20. Die Organisation der Turbellaria Acoela, von Dr. Lupwia von GrarF, Professor of Zoology and Comparative Anatomy in the University of Gratz. 90 pp. quarto. Leipsic, 1891 (Wilhelm Engelmann).—This work is an elaborate memoir on the Acclous Turbellarian worms. It is illustrated by ten plates, exhibiting their microscopic structure as presented in different species of the genera Amphicherus, Convoluta, Aphanostoma, Monoporus and Proporus. An especially interesting part of the volume is a sup- plement, on the structure and purpose of the chlorophyll cells of Convoluta Roscoffensis, by Dr. G. Peocrandt, Professor of Botany in the same university. IU. MiIscELLANEOUS SCIENTIFIC INTELLIGENCE. 1. Note on the recent eruption of Kilauea, Hawaiti.—A letter, from Rev. E. P. Baxer, of Hilo, dated March 8th, states the following facts: The eruption, or discharge of Halemaumau, mentioned on page 336, occurred on the 6th of March—the very same day of the year with that of 1886, making the interval just five years, and adding another to the number of Spring or wet-month eruptions. The lava ran out by some subterranean channel, at a slower rate than in 1886, a little of it still remaining on the 7th. The whole area gradually subsided and in two or three days, the cone had sunk out of sight, leaving in its place a crater-like cavity about as deep as that of 1886 [900 feet]. This crater has a talus half- way up fromthe bottom, making it conical below, and a sheer precipice above; and avalanches from the precipice continue to add to the talus. The diameters of the crater are by estimate three-fourths and half a mile. There were earthquakes in Hilo for a week or so after the 6th of March, and many also in Kapapala, 15 miles to the southwest of Kilauea, but all were light. It is inferred that the lava ran out under ground, in the direction of the discharge of 1823. As in 1886, none appeared above ground. [The cone that was so deeply buried at the eruption was the “ debris-cone,” whose condition for 1887-1888 is represented on plates in Vol. xxxv of this Journal, and also in the writer’s work on Volcanoes. It was early described by F. 8. Dodge as resting on the Jiquid lava; and to this its whole history, and the final event of its burial, attest. J. D. D. 2. Depths of 3000 fathoms and more in the Indian Ocean.— An area having depths of 3000 fathoms and more exists off the Northwest coast of Australia. In addition to earlier observa- tions between meridians of 100° and 106° E., and parallels of 18° and 25° 8S. new results were obtained in 1888 by the Eastern Telegraph Co.’s steamship “ Recorder,” under Capt. C. O. Madge. The depths found were from 3015 to 3393 fathoms, between the latitades 13° 40’ and 11° 22’, and the meridians 118° 42’ and 116° tit Miscellaneous Intelligence. 50’. The greatest depth was at the northeast extremity of this line, in latitude 11° 22’ and longitude 116° 50’. Just beyond, in latitude 11° 08’ and longitude 116° 38’, the depth found was 2860 fathoms.— rom the Report on Oceanic depths, issued by the Ad- miralty, Hydrographic Department, London, Jan., 1891. 3. Catalogue of the Crawford Library of the Royal Observa- tory, Hdinburgh. Edinburgh, 1890. This quarto of 500 pages in double columns contains the titles of the remarkable collection of books, pamphlets and manuscripts which the Earl of Crawford presented in 1888 to the Edinburgh Royal Observatory. Charles Babbage was a famous collector of rare and old books, and after bis death his entire library was bought by Lord Crawford, in 1872, and to this were added rare books from the library at Haigh Hall and many other books, by purchase, so that this collection at Dunecht had become one of the notable astronomical libraries of the world. In the present catalogue the full title is given of each book and pamphlet, and the Edinburgh Observa- tory and its Astronomer Royal, Mr. Copeland, have thus added largely to our resources in the Bibliography of Astronomy. 4. Dr. Goodale in New Zealand.—The third session of the Australasian Association for the Advancement of Science was held in Christ Church, New Zealand, and began Jan. 15th, 1891. Sir James Hector, presided. The meeting was a successful one, the attendance being about 470, and the number of papers read 74. Prof. Goodale, of Harvard University, represented the American Association, but no member of the British Association attended from England.— ature, March 26th. 5. Missouri Geological Survey.—Mr. Chas. R. Keyes of Des Moines, Iowa, has been appointed paleontologist of the Survey. Mr. Keyes is now at the Johns Hopkins University, Baltimore, but will report for duty in Missouri during the month of May. In the meantime he is occupied in the preparation of a report on the paleontology of the State, in which work he has already made considerable progress. The Journal of Comparative Neurology: A quarterly periodical devoted to the Comparative study of the Nervous System. Hdited by C. L. Herrick. Vol. I; pp. i-xviii, 1-106. Cincinnati, Ohio. A Journal of American Ethnology and Archeology.—-Kditor J. WALTER FEWKES. Volume I. 132 pp. 1891 (Boston and New York, Houghton, Mifflin & Co.) OBITUARY. James B. Macxrntosu, of New York City, died on April 15th, after a brief illness, aged 34 years. He was a skillful, active chemist, and besides work on the technical side he had made important contributions to mineralogical chemistry and his future promised bright in this direction; recent volumes of this Journal contain a number of articles by him and one of which he is part author appears in the present number. NEW MINERALS Never before offered for sale. We have all that is in the market of each of the following : Auerlite, a new Thorium silico-phosphate, found rarely with Zircon in Henderson Co., North Carolina. Only about 100 grams were found in a search of five weeks, and it is, therefore, likely to remain an exceedingly rare mineral. We have secured the original ‘‘ find” upon which the species was described (see A. J. S., this number, p. 438, and Dec., ’88). Price $1.00 per gram. A very few small, rough crystals at 50c. to $1.00 each. Aguilarite, a new sulpho-selenide of silver, from Mexico, described in this number of the A. J.S., p. 401, was secured by our Mr. Niven during his last trip. Less than a dozen specimens have been found altogether, and all but one show more or less complete alteration to Stephanite. All the specimens are well crystallized. The excessive rarity of the new species and its high cost in the locality compel us to charge considerable for it, but we have some small specimens, por- tions of the type material, as low as $1.50 to $5.00. Pollucite from Maime, described in A. J. S., March, ’91. The entire find (except such as was presented to the describer) has been purchased by us. Specimens of this mineral are essential to the completeness of every collection. The amount of the find was very small and we have already sold two-thirds of it, so that our cus- tomers are urged to send in their orders promptly. Prices 50c. to $7.90. Polycrase from South Carolina, described in A. J. S., this number, p. 423. We have picked over the entire ‘‘find”’ and have the best material there is, and all that will be sold as specimens. The crystals are mostly rough and .fragmentary, but are much superior to any European specimens we have seen for sale. The high percentage of the rare element scandium and the fact that this is the first occurrence of Polycrase in the U.S. renders the speci- mens doubly desirable. Prices 10c. to 75c. each. Monticellite from Arkansas, described in this number of A. J. S., p. 398, was first brought to notice by us. We can supply illustrative specimens at 25c. to $2.50. Coe Eudialyte from Arkansas, 25c. to $2.50. For many other recent additions to our stock see our other page of announcements. GEO. L. ENGLISH & CO., Mineralogists, 733 and 735 Broadway, New York. CONTENTS: Art. XLI.—Relationship of the Pleistocene to the Pre pleistocene of the Mississippi Basin, south of the glacia- tion limit; by T. C. CaamBErRLin and R. D. Sarispury- XLIL—Measures of the Intensity of Solar Radiation; by Wo FP RRRELM Oost XLITI.—Age of the Saganaga Syenite; by H. V. WincHELL XLIV.—Self-feeding Sprengel Pump ; by By. Wess XLV.—Contributions to Mineralogy, No. 50; by F. A. GENTH; with Crystallographic Notes by 8. L. PENFIELD and UV: PIRsson 220 ou a oo a XLV I.—Contributions to Mineralogy, No. 51; by F. A. GenTH XLVII.—Columbite of the Black Hills; by W. P. Buaxe.. XUVIII.—The Raised Reefs of Fernando de Noronha; by HN, REpuEeyy! 2 2) a ee XLIX.—Cause of Active Compressive Stress in Rocks and Recent Rock Flexures; by T. M. RrapE__--.-____-.- L.—Phosphates from the Black Hills ; ; by W. P. Heappen- LI.—Certain Peculiarities in the Behavior of a Galvanometer when used with the Thermopile; by E. Mrerrirr-. ---- LII.—Supplementary Notice on the Polycrase of North and Page 359 | 378 386 390 | 394 401 4038 406 409 415 417 South Carolina; by W. E. HippEn and J. B. BE 423 SCIENTIFIC INTELLIGENCE. Chemistry and Physics.—Speed of Chemical Reactions in Jelly, REFORMATSKY, 425.—Direct-reading of Volumes in Vapor-density Determinations, LuNGE and NEUBERG, 426.—Hydrazoic Acid, CURTIUS and RADENHAUSEN: Production of ° Arabinose from Wheat bran, STEIGER and ScHULZE: Distinguishing Arsenic from Antimony, DENIGES, 427.—Priestley’s EKudiometric method, WANKLYN: Crystalline Liquids, LEHMANN: Refractive indices of Water, BRUHL, 428.— Genesis of the Elements, W. CRooKES, 429.—Geschichte der Photographie. C. SCHIENDL, 430.—Die Elektrischen Verbrauchsmesser E. DE Fopor: Das Total- reflectometer, etc., PULFRICH: Appleton’s School Physics, 431.—Handyvy Srter- buch der Chemiker, C. SCHAEDLER: Bibliotheca Polytechnica, 432. Geology and Natural History.—Rock-fracture at the Combined Locks Mill, Appleton, Wisconsin, F. CRAMER, 432.—Bulletin of the Geological. Society of America, Vol. II, 434.—Cambrian fossils in the Stockbridge limestone of Vermont, J. E. WoLFr: Geological Survey of Kentucky: Geological Survey of Missouri, S. A, MILLER: Geological Survey of Arkansas, J. C. BRANNER, 435.—Geological Survey of Texas: Geological Survey of Alabama: Bibliogra- phy of Paleozoic Crustacea from 1698 to 1889, A. W. VoGDES, 436 —Oreaniza- tion of the Fossil Plants of the Coal-Measures, W. ©. WILLIAMSON, 437,— Catalogue of the Fossil Cephalopoda in the British Museum, Part II, A. H. Foorp: Mineralogical notes, W. EK. Hippen and J. B. MAcKINTOSH, 438.— Mineralogical notes, W. HK. HipprEn, 439.—Tenth Annual Report of the State Mineralogist of California, 440.—Algemeine Chemische Mineralogie. DOELTER: Index der Krystullformen der Mineralien, GoLpDScHMIDT; Gray’s Manual of Botany, WATSON and COULTER, 441.—Hypertrophie des lenticelles chez la pomme de terre, etc. Devaux: The Nursery-Book, Guide to the Multiplication and Pol- lination of Plants, BAiLny, 442.—Turbellaria Accela, L. von GRAFF, 443. Miscellaneous Scientific Intelligence.-—Recent eruption of Kilauea, K. P. BAaKmr: Depths of 3000 fathoms in the Indian Ocean, 443.--Catalogue of the Crawford Library: Dr. Goodale in New Zealand: Missouri Geclogical Survey, 444, Obituary.—-J AMES B. MACKINTOSH, 444. rs Tt math SM re ares he ee ee Y fale mera yo E : | JUNE, 1891. Established by BENJAMIN SILLIMAN in 1818. | AMERICAN JOURNAL OF SCIENCE. EDITORS JAMES D. anp EDWARD 8S. DANA. ASSOCIATE EDITORS Prorrssors JOSIAH P. COOKE, GEORGE L. GOODALE AnD JOHN TROWBRIDGE, or CamBripGE. Prorrssors H. A. NEWTON anv A. E. VERRILL, or New Haven, Proressor GEORGE F. BARKER, or Paiavetputa. | ts | THIRD SERIES. VOL. XLI.—[WHOLE NUMBER, CXLI.]. No. 246.— JUNE, 1891. NEW HAVEN, CONN.: J. D. & B.S. DANA. ifs oN $ TUTTLE, MOREHOUSE & TAYLOR, PRINTERS, 371 STATE STREET. AAT OLAS LEAL ERIN A RN RELATE TR El PAA TAT NST ATO AAR RE OE Published monthly. Six dollars per year (postage prepaid). $6.40. to foreign sub- ___seribers of countries in the Postal Union. Remittances should be made either by -_— money orders, registered letters, or bank checks. te Gal ee ANS GEO. L. ENGLISH'S ANNOUNCEMENTS, Mr. ATKINSON of our firm sailed on the Etruria, May 16th, for an extended collecting tour through Europe. We hope to announce next month some of the many important additions to our stock which we expect as the result of his trip. Mr. NIVEN of our firm started May 9th on another long tour through the far West and Mexico. Already returns from Missouri and Colorado are reported and some remarkable specimens have come in. Among them is A magnificent specimen of Minium, 634 by 4 by 2 inches, weighing over 5 lbs. We believe this specimen to be the finest ever found. A mass of Horn Silver, nearly pure, 3 by 3} by 24 inches, weighing 2 lbs. 3 oz. was also secured by Mr. Niven. A much more wonderful specimen of this mineral has just been received from New Mexico. It is 7 by 6 by 4 inches and weighs over 12 lbs., and with the exception of a little native silver, the entire mass is pure chloride of silver, giving it a bullion value of over $125.00. Gold beautifully crystallized and in wires, has also been received among other Colorado specimens from Mr. Niven, and some Fine Wire Silver, Embolite, Epidote crystals, Cerussite crystals, etc., are in the same lot. Missouri specimens include most beautiful ‘‘ ruby blende” crystals, * yellow calcites, etc. Proustite from Chili.- A superb group (2 by 24 by 14 inches) of stout scalenohedral crystals, 4 to 14 inches long, has just come in. Another very beautiful small group. Hiddenite crystals. A fine, large lot of singly and doubly terminated erystals has been secured this month. We can supply these gem crys- tals at lower prices than ever before. Beryllonite crystals. We have succeeded in purchasing a large number of the best crystals ever found of this rare mineral, the lot embracing probably 75 to 100 choice crystals, besides many good cleay- age specimens which latter we can sell as low as 10 cents each. Childrenite crystals from Maine (new). A few very excellent speci- mens of this rare mineral have been received from a new locality in Maine. The find is well worthy of especial notice. ; Other Rare Minerals Recently Added. Durangite, fine crystals; Roscoelite from both Colorado and Cali- fornia; Aguilarite, the new sulpho-selenide of silver from Mexico; Durdenite, the new ferric tellurite from Honduras; Auerlite, the new hydrous silico-phosphate of thorium from North Carolina; Polycrase from South Carolina; Monticellite, Manganopectolite, Leucite, Eudia- lyte, etc., from Arkansas, Pollucite from Maine; Axinite, pale lemon- yellow crystallized Willemite, Niccolite, etc., from Franklin, N. J.; Cacoxenite from Pa., and many other equally desirable minerals, Azurite. A lot of splendid crystals from Arizona. Sulphur. Magnificent large groups and single crystals, Sicily. _ Pink Grossularite Garnets from Mexico, the most popular mineral we have ever had. Our 100 page Illustrated Catalogue, 15c. ; bound, 2dc. GEO. L. ENGLISH & CO., Mineralogists, 783 & 735 Broadway, New York. THE AMERICAN JOURNAL OF SCIENCE [THIRD SERIES.] +@+ Art, LII.—TZhe Study of the Harth’s Figure by means of the Pendulum ; by E. D. PREston. [Read before the Brooklyn Institute Feb. 26, 1891. Published by permission of the Superintendent of the U.S. Coast and Geodetic Survey. | flistory. THE idea of finding the size and shape of the earth is probably one of the oldest in the history of science. Each age has added to the knowledge of the age before it, and each one has by its additions to existing data contributed to the solution of the problem. From the time of Anaximander 600 years before Christ, when it was thought to be a cylinder with a height equal to three times its diameter, down to the last deductions of Clarke aad Bessel which point to aspheroid with three unequal axes, successive theories have been tested by physical observations and corrected or modified by the facts revealed by experience. It is uot worth while to review all the ancients thought or did on this subject. Such a study would be interesting but not profitable for the present purpose. The turning points or mile-stones on this highway of inquiry may, however, be noted as showing how slow has been the progress towards what we now believe to be the truth. The cylindrical theory supposed the land and water to be on the upper base. Seven successive generations accepted this idea and when it was no longer considered tenable a cube was sub- stituted for the cylinder. What a striking difference between the intellectual activities of an age that required several hundred years to pass from a cylinder to a cube, and was satis- fied with this conclusion, and an age that in one-half the time has determined the distance of the heavenly bodies and studied AM. Journ. Scl.—TuHirpD Series, Vout. XLI, No. 246.—Jung, 1891. 446 E.. D. Preston—Study of the Earth’s their composition. Aristotle, three centuries before Christ, supposed the earth to be spherical, and Eratosthenes 100 years later was the first to actually compute its dimensions from observations of the sun’s shadow. Nothing of course was done in this direction in Europe during the dark ages. With the revival of learning in the 15th century the spherical theory again took shape and during the 16th (1525) Fernel determined the earth’s dimensions essentially as it is done to-day; that is, by measuring the distance between two points and observing their difference of latitude. From this time on, it being admit- ted that the shape of the earth was something like a globe, the question was and still is, how much does the surface depart from that of a perfect sphere, and what is its actual size. In 1669 Picard measured the length of a degree by means of tri- angulation. This was a long stride in advance of all previous work, because here for the first time spider lines were used to mark the optical axis of the telescope. Newton used his value in the proof that the moon falls toward the earth in obedience to the law of universal gravitation. A score of years later Cassini greatly extended the measurement of ares in France, but from some unfortunate circumstance his results were con- trary to the Newtonian theory, and also to what had come to light a few years before, namely, that a pendulum vibrates much slower at the equator than in middle and higher latitudes. This gave rise to a controversy which brought about the famous work of the French academicians in Lapland and in Peru. Their labors effectually closed the question of the relative lengths of the polar and equatorial axes, and since then we have simply been making closer and closer approximations to the still unknown truth. From the accumulation of refined observations other knowledge than that directly sought has come to light. It is found that an ellipsoid better fits the observations than a spheroid, and there seem to be physical reasons why the northern and southern hemispheres should not be exactly equal. Moreover, the actual surface of the earth departs everywhere from the mean figure adopted in all the- oretical computations, and it is generally admitted that this mean figure cannot be corrected until we know something more about the actual figure. The quantities involved. Now to recount: first we had the cylinder, then the cube, then the sphere with its variations into spheroid, ellipsoid and geoid. There is where we are at present; and what I shall have to say will be touching the instruments and methods by which the eccentricity, one element in the earth’s figure, is Figure by means of the Pendulum. © 447 determined. Let us first understand what kind of quantities we are dealing with. The difference between two radii of the earth, one being polar and the other equatorial, is about thirteen miles. This bears the same relation to the whole radius that one inch bears to twenty-five feet. So that had we a model of the earth in its true proportions it would be quite impossible to see with the naked eye whether it was flattened at the poles or not. The first practical demonstration of a change of the force of gravity with a change of latitude was had a little over 200 years ago when a clock was carried from France to Guiana. This clock kept accurate time in Paris but lost two minutes per day in Cayenne. The pendulum had to be shortened about 4, of an inch in order to make it beat seconds, as it had done in a more northern latitude It was thus seen that the pendulum could be used to measure the force of gravity. The change in the time of one oscillation over limited areas is, however, very small; one mile in distance making a difference of one two-millionth of a second in the time of vibration; or stated in another way, a pendulum thirty-nine inches long that beats seconds at the equator would only have to be lengthened by 4 of an inch to make it beat seconds at the pole. When we consider that one-quarter of the entire circumference of the earth only changes the length of the second pendulum by its sty part, it is evident that a change of latitude even for a country as large as the United States affects the pendulum by what may be called a minute quantity. Then the force of gravity changes with the elevation; but our highest mountains only alter the time of oscillation by ;.45 part when distance alone is considered, and the effect is even less than that if the attraction of the mountain is taken into account. Of this we shall speak later. It is thus seen that in all work pertaining to the measurement of the force of gravity we are obliged to deal with very small quantities and that methods must be devised delicate enough to appreciate them. How far these have been successful may be judged from the fact that in- dependent determinations of the time of an oscillation do not differ as much as the one hundred thousandth part of a second. It is not asserted that differential gravity is always known to this degree of accuracy, but simply that there is no difficulty in making the pendulum repeat itself with no greater error than that mentioned. When we come to measure the absolute force of gravity, besides determining an interval of time, we are required to measure an interval of space. This can be accomplished with a degree of precision far exceeding that attained in the time measures. Not only is it much easier to obtain the one hundred thousandth part of a meter than to get the corresponding fraetional part of a second, but the effect 448 Li. D. Preston—Study of the Earth’s of an error in the time of an oscillation is doubled when it is referred to the length of the pendulum; so that the weakest part of the entire investigation is the length of the time of one oscillation. or this reason it has been assumed that the pen- dulum can never be made to compete with metal bars in giving us a uniform standard of length. Whether it is better to refer our standards to the wave-length of light, or to some material thing involving permanence of capacity, is not in the exact line of our thought at present. Objections have been urged against both these methods. The former because it was sup- posed the earth might eventually move to a region of space where the wave-length of light was different, and the latter because a capacity-measure may change its three dimensions unequally so that the permanence of its capacity would be no proof of the permanence of one of its linear dimensions. What most concerns us is to know that the seconds pendulum is not our best standard of length. Method of Study.° The most advantageous way of treating the figure of the earth is now conceived to be different from that employed hitherto. The measurement of an are of the meridian by triangulation is not the best means of arriving at the flattening although it gives the actual size of our planet with an accuracy fully equal to the requirements of the case. The problem should be separated into two distinct investigations, and to each one of them methods should be applied, that will deter- mine the unknown quantities to the best advantage. Let pen- dulum observations and the moon’s parallax determine the flattening and let triangulation measure the actual size. Then we shall have each method working in a field where it has the greater power and the results will be correspondingly better. When the flattening is determined its value may be used as a known quantity in the equations that determine the length of the axes. This method is suggested by Professor Harkness. Admitting then that pendulum observations must be employed for the study of the earth’s figure, what is the best way of doing it? Here we are confronted by two distinct schools. The Germans, followed by the Russians and Swiss, have always favored absolute determinations of gravity. The Eng- lish stand as the exponent of the rival school and only meas- ure differentially. The U.S. Coast and Geodetic Survey has followed both methods to some extent, and now seems to be favoring differential measures especially for a preliminary sur- vey of the country. The difference between the methods is briefly this: the Germans measure the actual force of gravity Figure by means of the Pendulum. 449 at every station. This requires an accurate determination of the length of the pendulum as well as the time of oscillation, and also necessitates the measure of the vibratory movement of the stand on which the pendulum swings. The English content themselves with relative measures from one station to another and simply compare the forces of gravity, by counting the number of oscillations made by the ‘same pendulum in the two places. They determine absolute gravity only at a base station. It is evident that the latter method is immeasurably superior in point of economy, and we may say that it can be made to yield results fully equal in accuracy to those of its rival school. Moreover the differential method has the great advantage of eliminating all those sources of error that are practically the same for each station. General Results of Pendulum Work. Knowing now which method best suits our purpose a still further question arises. How accurately shall we do the work ? Certainly not as accurately as we can. ‘That would be bad economy from every point of view. Nothing is gained by measuring the force of gravity to its 1/100000th part to deter- mine local deflections when these variations themselves are several times as great. No fact is more certainly demonstrated than that certain places on the earth’s surface present varia- tions of the force of gravity quite exceeding anything to be expected either from ‘the amount or density of the adjacent matter. ‘These anomalies in many cases bafile all attempts to classify them, but one general result seems to be that moun- tains are light and islands are heavy. Some of the first, if not the very first pendulum observations made, gave the strange result that the Andes in Equador are not much heavier than water. TIoster’s celebrated series on Green Mountain gave a result indicating that this voleanic formation is about twice as heavy as cork. The sacred mountain in Japan has given a similar result, namely, that the mountain is lighter than would be indicated by its volume and density. Haleakala in the Hawaiian Islands seems to be of the same mean density as the rocks on its surface. One observer has even gone as far as to say that the Alleghany Mountains in Pennsylvania weigh less than nothing, meaning by this, that if gravity at the summit be corrected for elevation. the result is not more than gravity at the base, showing the downward attraction of the mountain to be practically insigniticant. If we glance at a few island stations, gravity is found to be mostly in excess of what a ought to be. The most striking examples are Fernando, S Helena, Ascension, Minecoy, Isle of France, Bonin, Mani a 450 i! D. Preston—Study of the Earth's Caroline Island. At all of these gravity is more than theory demands, and they are generally islands situated in a deep sea and considerably removed from continental masses. This ex- cess has in many cases been shown to be more than can be due to the extra attraction of the water, so that there must be a real increase in density under the ocean bed. We may there- fore look to pendulum observations for information in regard to the internal structure of the earth. Deviations from the law of uniform density may be greater than has hitherto been supposed. Two well known authorities on the subject have already expressed the belief that the center of gravity of the earth does not he at the center of figure, but is to be found inside the hemisphere that is under the Pacific Ocean. We have an example of this excessive seaward attraction in India. When a chain of triangles was thrown across the pen- insula of Hindoostan from the Bay of Bengal to the Arabian Sea, it was expected that the astronomical amplitude of the are would exceed the geodetic amplitude: in other words that that the plumb-line would be deflected towards the high table lands over which the are was measured. The contrary was found to be the case. The seaward attraction was more than that from the continent, and an identical result followed from two independent arcs. We may therefore accept the fact as proven, that the attraction of continental masses is in some way partially compensated by a deficiency of density in the immediately underlying strata. It may be asked what rela- tion this defect of gravity on high table lands, as revealed by the pendulum, bears to the horizontal attraction as brought out by a comparison of astronomical and geodetic latitudes. The Himalayan attraction on the plumb-line at Dehra, a point less than 50 miles distant and with an elevation of 2000 feet, is. 1/5000th part of the total force of gravity at the earth’s surface, whereas the defect of gravity at or near the summit is 1/200Uth part of the total force. This somewhat strange result may be explained in two ways. First the deflection at Dehra may be produced by matter lying between this place and the summit ; or the great plateau of Thibet with an average elevation of 15,000 feet may exert the attractive influence on Dehra, and the strata immediately under the pendulum station at the sum- mit may possess a very small density. This last view would seem to be supported by the fact that there is a deflection in. azimuth as well as in latitude at Dehra. The condensation theory assumes that all pyramids of matter having their vertices at the center of the earth and having equal bases, contain equal amounts of matter, and that the ver- tical attraction at any point on an elevated plateau is equal to that obtaining at a point on the sea-level immediately under it,. Figure by means of the Pendulum. 451 if we imagine the plateau to be compressed down to that level. An equipotential surface would be severa! hundred meters below the surface of the actual ocean, and as much above the mean continental surface. The Earth’s Geometrical Figure. It is probably demanding too much at present, to ask the acceptance of the tetrahedral theory of the earth’s figure, but in connection with gravity work allow me to call attention to some points of the argument. It is well known that gravity is In excess at island stations. If we admit the tetrahedral system, these ocean areas are really nearer the center of the earth, and hence should show increased gravity while the con- tinental masses would tend to increase the effect still further by elevating the surface of the sea in their immediate vicinity. It has been shown that the attraction of the Himalayas would elevate the surface of the ocean immediately under them by nearly 1000 feet. This would be equivalent to increasing the distance from the earth’s center by 1/16,000th part of itself and gravity would be diminished by twice this amount, which is a very appreciable quantity. Besides nothing is more in accordance with the action of physical laws than that the earth is contracting in approximately a tetrahedral form. Given a collapsing homogeneous spherical envelope, it will assume that regular shape which most readily disposes of the excess of its surfaces dimensions, or in other words the shape that most easily relieves the tangential strains; for while the sphere is of all geometrical bodies, the one with a minimum surface for a given capacity, the tetrahedron gives a maximum surface for the same condition. Experiments on iron tubes, on gas bubbles rising in water and on rubber balloons, all tend to bear out the assumption that a homogeneous sphere tends to contract into a tetrahedron. These ideas regarding the shrinking nucleus of our globe and the consequent form assumed by the surface are not by any means new. They have long since been formulated by Green and have found favor in France. Mr. Green has even gone so far as to study the land and water areas of the globe, and has succeeded in finding a close correspondence between the actual features and those required by the theory. Africa and Europe are considered as one continent, and a depression is assumed between Europe and Asia. In point of. fact there was a time when a glacial sea existed along the Siberian fron- tier and communicated with the Caspian waters. Admitting also a polar sea and an antarctic continent, both of which seem highly probable; there seem to be reasons for the acceptance any “F 452 Ei. D. Preston—Study of the Earth's of the theory. Then again, it seems quite well ‘established that our present continental forms are very old, which would indicate that whatever form the contracting earth may be tak- ing, it has been gradually settling into this shape for many millions of years. No reference is “made at present to changes or. the earth’s surface, consequent upon outside conditions. The changes in the eccentricity of the orbit which has its greatest value at intervals of about 2,500,000 years certainly produce vast changes in the distribution of matter, from the accumulation of ice and snow, and from the shifting of the -ocean currents; but these are “purely surface phenomena, and do not pr obably affect the permanent shape of the contracting nucleus. Besides, any change produced at a time when the eccentricity was at a maximum, would be counterbalanced When the next minimum occurred somewhat more than a million years later. But the earth’s contraction goes on indefi- nitely throughout all time. This brings us to a consideration of The Earth’s mean density. The pendulum has recently been employed in such deter- mination. It is weil known that during the early part of this century Dr. Hutton conceived the idea of determining this constant by comparing the attraction of the earth with that of a mountain of known dimensions. The method of course rests on the assumption that the volume of the mountain is a determinable » quantity and also that the mountain is solid. Latitude obser- vations were made on the north and south flanks and the results were compared with the actual differences of latitude obtained by connecting the points by triangulation. This way of getting ‘the earth’s mean density has been employed in a number of cases since Dr. Hutton’s time and always with approximately the same result. It is evident now that if we have a means of getting a value for the density of the mountain that is independent of the latitude observations we get a rig- orous check on the final result. This modification of the problem was applied with entire success in the Sandwich Islands in 1887; and not only was the mountain much larger and higher than in Dr. Hutton’s work, but its form was much more accurately known. The entire ‘island of Maui rises to an elevation of 10,000 feet and has on its summit the crater of Haleakala, which is twenty miles in circumference and half a mile deep The whole mountain has been contoured from the sea to the summit giving differences of elevation for every 500 reo) feet. This gave a means of calculating with a high degree of | - Pps: Figure by means of the Pendulum. 458 precision the disturbing effect of this huge mass of Java on a plumb line suspended north or south of it. But the mass of the mountain enters as one of the unknown quantities. This quantity was determined by measuring the force of gravity at the sea-level and at the highest practicable point by means of the pendulum. Knowing the mass of the mountain and there- fore its mean density, its attraction at any given point is easily deduced. Now the result of the work was this: the pen- dulum observations showed that the mean density of the mountain was very nearly one-half that of the earth’s mean density, that is, that the island is a little more than two and one half times as heavy as water. This value would lead us to expect, at the point selected on the south shore, a disturbing effect on our star observations of 28’... When the two points on the north and south sides of the island were connected by triangulation a discrepancy of 29” was brought out. The agreement between the results obtained by two independent methods is so close as to give us considerable confidence in the astronomical and geodetic parts of the work as well as in the measurement of the force of gravity at the upper and lower station. Besides this, rock specimens were secured from many parts of the island at different elevations. Their densities were carefully determined at the bureau of weights and measures in the Coast Survey Office. When a mean value was taken we arrived at the result that the mean density of the mountain is somewhat more than that of the rocks found on its surface. This is contrary to the result generally obtained on mountains and high table lands; and it is notably in oppo- sition to determinations on continental mountains. But let us remember in this connection that the sea level in the neigh- borhood of continents may be considerably disturbed by the attraction of the land, and that a single mountain in the middle of a deep sea would have practically no influence in elevating the surface of the ocean. In point of fact the island of Maui could not elevate the surface of sea around it by more than ten feet—a quantity easily neglected in this investigation. One word about the correction for Continental attraction. We know that on a sphere at rest attraction varies inversely as the square of the distance from the center, but in the case of a rotating spheroid this assertion is not true. The actual diminution of gravity from the pole to the equator is about zooth part of itself—this is in part due to the centrifugal force in consequence of the earth’s rotation and in part to the spheroidal shape into which the earth has been thrown by this rotation. Bouguer was the first to call attention to the fact 454 EE. D. Preston—Study of the Earth’s that besides the influences just mentioned some allowance should be made for the matter lying above the sea level; and his formula, based on the relation between the mean density of the earth and that of the crust, is still employed. The pro- priety of this method of treatment has, however, several times been questioned. In the first place, because observation seems to show mountains and table lands to be much too light, and in the next place, because the excess of gravity noticed at island stations is very nearly accounted for by making a cor- rection for the downward attraction of the sea. Of course we meet with many anomalies in gravity determinations, but it would seem better in the present stage of the subject to make some disposal of the influence of the continents. The estimate may indeed be a rough one, afterwards to be modified as more data accumulates, but in the light of our present knowledge we may apply the corrections as follows: at a station say 1900 feet above sea level a seconds pendulum will lose eight seconds daily on account of its elevation, and it will be accelerated in the same time by three seconds from the influence of the mountain matter, so that both effects together would cause a loss of five seconds per day.. This rule of course does not hold strictly at great elevations; nevertheless it was found approxi- mately true in the Sandwich Islands where the pendulum was carried to an elevation of about 10,000 feet. Here we had a daily loss of 41° from elevation and an acceleration of 13° from the mountain attraction giving a total loss of 28° daily. This agrees tolerably with the ratio above stated. Changes of Latitude. Closely connected with the variations of the force of gravity are the changes of terrestrial latitudes. Whether the earth’s crust is floating on the plastic or semi-plastic nucleus, and really shifts its position with reference to the axis of rotation, or whether latitudes change by reason of the moving of quan- tities of water and air, it is now impossible to say. Within the last year it has been abundantly demonstrated that latitudes may have an annual variation of a considerable fraction of a second. The International Geodetic Association of Europe has taken the matter up and will send an observer to Honolulu in order that simultaneous observations may be made on oppo- site sides of the earth. The U.S. Coast and Geodetic Survey has been asked to codperate and will also send an officer to the Sandwich Islands, besides observing continuously at Wash- ington, San Francisco and other points. The Royal Obser- vatory at the Cape of Good Hope will engage in the work and probably other permanent stations may be established in the southern hemisphere. Figure by means of the Pendulum. 455 The outcome of all this will be that when observations from opposite sides of the earth are compared we shall be able to decide whether the axis of the earth actually shifts its position, or whether changes of latitudes are due to transfers of molten matter below the crust. If the results at Berlin and Honolulu show opposite phases at the same time, we should expect the latitude to be stationary at Washington, because this point is one-quarter way around the globe, or midway between the other two stations. The conclusion from this would be that there is a real motion of the pole and not a transfer of material inside the earth. There is a decided maximum and minimum within twelve months with a larger maximum and minimum in a five-year period. In addition to this the Greenwich observations show a long period of inequality extending over sixty years. The cause of the short period movements has been ascribed to the interference of the motion of the axis of inertia with that of the ten-monthly period of the axis of rotation. It can certainly be assumed that the sun and moon produce atmospheric tidal effects changing with the seasons, and it is also known that the shifting of a mass of water covering 4, the earth’s surface and being 0°10 ineter thick would cause the axis to move 0’""16 —a quantity which is quite measurable in all latitude work of precision. As this depth of water corresponds to an atmos- pheric pressure of about 0-007 meters it is evident that exten- sive changes in the density of the air may produce a slight change in the position of the earth’s axis; so that it would seem well worth while to measure the force of gravity from time to time at the same place in order to detect changes that would most probably be produced by changes of latitude. Practical Methods. When we come to the actual field work, again several methods present themselves for our consideration. The ulti- mate end of the observations is to find how long it takes the pendulum to make an oscillation at a given temperature and atmospheric pressure. Most of the slight corrections necessary to reduce the different experiments to the same conditions, and thus make them comparable, may for our present purpose be passed over in silence. The reduction to an infinitely small are involving only simple geometrical considerations is easily disposed of. ‘The influence of the temperature and density of the air requires special treatment, and has been made the sub- ject of careful study by all pendulum observers. The air not only has a buoyant effect on the oscillating body, but by reason of its viscosity adheres to the pendulum and is drawn along 456 £. D. Preston—Study of the Karth’s after it. The atmospheric effect has been treated in one system of equations, where the unknown quantities vary directly as certain powers of the pressure and inversely as powers of the temperature. All these corrections are of much more importance in absolute determinations than in relative ones. This brings us to the different methods of observing. T'wo methods have been chiefly followed. First by noting coincidences between the gravity or experimental pendulum, and the pendulum of a clock set up a short distance away. This is by far the most easy and accurate method of getting the length of one oscillation of the gravity pendulum. The second method is by registering on a chronograph the passage of the pendulum across a fixed point of reference. Forty of these transits suffice to give a mean value, which carries the accuracy of this part of the operation far beyond that attained in deducing some of the other necessary corrections. The probable error of the mean of a chronographic set is only 0:008 of a second and when this is divided by 15000, the number of oscillations In one swing, we get an accuracy beyond one millionth of a second. This is all that can be desired, but the method of coincidences is still more accurate while it is much less difficult to observe. We may commit an error of many seconds in the time of a coincidence without vitiating the result. The distinctive feature of the last method is this: when we commit an error of one second in noting the time, we do not change the value of one oscillation in the ratio of this error to the length of the swing, because both pendulums are moving along together. An error in the time of coinei- dence only means that the result will be in error by an amount equal to the ratio, one has gained on the other in the short time between ne true et nen anes and the one noted, multi- plied by the ratio of the error to the whole period. To illus- trate by a special case, suppose that in 600 oscillations of the clock pendulum, the gravity pendulum loses two oscillations, and suppose that the coincidence was erroneously noted after 602 oscillations had been made instead of 600. ‘This error is 1/300th of the interval, but far from introducing an error of 1/300 in the length of one oscillation, the error is only 1/300th of the ratio of. the gain of one pendulum on the other, that 1s 1/300 of 1/300 or say 000001. It is thus seen that the accuracy of the result is a function of the length of time between two coincidences, and that the longer the interval the more accu- rate will the result be given. One might suppose therefore that the coincidence period might be indefinitely long, but there are economic considerations bearing on the question. For instance we cannot afford to wait very long for the coincidence because this would entail too much loss of time. Therefore in Figure by means of the Pendulum. 457 general intervals should be chosen which are not longer than are necessary to secure the desired accuracy, and the swing should be repeated in order to eliminate accidental errors. In the chronographie method, an error in the determination of the interval between the first and last observation is sim ply divided by the number of oscillations in the interval, and therefore affects the result much more than by the coincidence method. There have been many ways devised for noting these coinci- dences. I shall first call attention to a few of the older methods which leave nothing to be desired as to accuracy, but which have been superseded by an elegant arrangement de- vised by Professor Mendenhall and which, while giving all the accuracy needed makes the observation both simple and easy. First we had a piece of card-board fastened to the clock pen- dulum. This card-board had on its surface a number of spots which were seen to oe at each coincidence of phase in the motion. The time of disappearance and reappearance were noted and the mean taken for the true coincidence. [or in- ereased accuracy a number of spots were observed, and for convenience in taking the time the spots were arranged in the form of a curve, resembling a hyperbolic spiral, which would give about equal times between successive disappearances for all amplitudes of oscillation. This method was modified. in the case of the Peirce pendulums by placing a scale on the clock pendulum and a small needle point on the gravity one. This last procedure is in direct violation of the whole theory of differential gravity measures, namely, that the pendulum must undergo no change from one station to another. However, as the mass added is exceedingly small, and besides is placed very near the center of oscillation, where theoretically it would have no influence whatever on the time of vibration, the method is considered admissible. Both the preceding ways are applicable only to two moving pendulums and suppose them to be of equal length. The methods depend on sight alone. Coincidences have also been observed by the eye and ear method, by comparing the beat of an ordinary sounder used in telegraphing, with the transit of a pendulum across the vertical thread of a telescope. This avoids carrying a clock from station to station, a break circuit chronometer furnishing the beat every second. The method has not been very extensively employed, as it requires consid- erable practice on the part of the observer. We now come to the last way, and which is believed to be in many respects the best: and here we have to do, not with two pendulums, beating approximate seconds, but with a single pendulum beating half seconds, whose coincidence must be 458 L. D. Preston—Study of the Earth's noted with a chronometer beating whole seconds. This re- quired the invention of an entirely new kind of apparatus. It was evident some means must be had by which the coincidence could be noted optically. For this purpose the chronometer was made to open every second the armature of a relay to which was attached an upright thin piece of metal. This metal was perforated by a thin slit which by the movement of the armature passed before a fixed slit a short distance in front of it, so that a light suitably disposed gave a flash every time the chronometer broke the electric current. The apparatus was placed about ten feet from the pendulum, and was so adjusted that the beam of light from the slit fell on two mirrors, one of which was on the pendulum and one near by it. The former was therefore movable by the motion of the pendulum while the latter was stationary. From these mirrors the beam of light was reflected back into the observer’s teles- cope. When the pendulum was at rest, the observer saw two illuminated slits every second in the field of view, but with the pendulum in motion the flash that came from the pendu- lum mirror could only be seen when the pendulum happened to be near its equilibrinm point. It is evident that if the pen- dulum makes exactly two oscillations for every second of the chronometer, the relation of the images will not change. and we shall see a double flash every second in the middle of the field of view. But if the time of oscillation of the pendulum is slightly different from a half second, it will not return quite to its former position by the time the next flash occurs, and we shall have its image displaced with reference to the one from the fixed mirror. Here then we have two necessary con- ditions for the appearance of the flash from the pendulum. First the chronometer must open the slit, and second, the pen- dulum at this instant, which has a duration of about 1/100th of a second, must be in such a position that the image of the slit will be reflected back into the observer’s telescope. We only need now a point of reference to which the motion of the mov- able image may be referred. This is furnished by the flash reflected back from the stationary mirror, and as the image from the pendulum is seen to pass slowly across the field of view, the time is noted when the two images coincide. Tor pendul um A, the time of oscillation exceeded half a second by 00066 seconds, which gave a coincidence interval of 6™ 15*. This was adopted for the other pendulums. Inasmuch as it was contemplated to use these instruments in all parts of the United States and at all altitudes, it was necessary to consider the effect of a change of latitude and elevation on the coinei- dence interval, because a period might be chosen at Wash- ington, which would make the intervals too long for conven- Figure by means of the Pendulum. 459 ience on the Canada frontier and too short for accuracy on the Gulf of Mexico. A compromise was made between the several conditions and the above mentioned interval of 6™ 15* chosen. It so happens that the effect on the coincidence period is about the same, whether we pass from the latitude of Washington to the Gulf of Mexico, or carry the pendulum from the sea level to the top of Pike’s Peak; the height in the latter case having the same effect as the change in latitude in the former. In the new work proposed by the Coast and Geodetic Sur- vey all experiments are to be made at a given atmospheric pressure. This will be about a mean value of those actually found in practice. Air will therefore be forced into the cham- ber at mountain stations, and pumped ont at the lower ones. It being decided to swing the pendulums in an enclosed space, the interesting question came up, how close can the pendulum be placed to the walls of the chamber, without influencing the time of oscillation; or in other words, how small can we make the box and still have the pendulum swing just as it would in the open air. Experiments were made with boxes of different sizes and shapes. The result generally stated was that the effect of the sides of the chamber only began to be felt when they were within about one inch of the moving body, and that what is known as “skin friction” is more effective than im- pact friction. That is to say that proximity of the wall to the side of the pendulum has more influence than nearness in front or back of it. The viscosity of the air is indeed an important factor in the investigation, as it is well known that besides the buoyant effect of the air it adheres to the pendulum and is drawn along with it. This influence has been studied both theoretically and practically by Stokes, Green, Peirce and others, and has furnished some fine examples of mathematical analysis. The temperature of the pendulum is found by means of another pendulum of exactly the same shape, size and material, except that the knife edge is of hard rubber instead of agate. This auxiliary pendulum is suspended inside the receiver. To it is attached a thermometer, whose bulb is encased in filings of the metal imbedded in the stem of the temperature pendu- lum. The presence of this auxillary instrument has no appre- ciable effect on the period of the swinging pendulum, either from air disturbance or from the vibratory movement of the support. This fact was carefully determined by experiment. In the last cruise of the U. S. Man-of-War Pensacola, an officer of the Coast and Geodetic Survey was sent to determine the force of gravity at some stations in Africa, and on some islands of the North and South Atlantic. The computations have just been completed, and the results are in conformity 460 Lf. SJ. H. Merrii—Post- Glacial History with the theories exposed in the body of this article. The stations on continents whether in Africa or America show a defect of several oscillations per day in the movement of the pendulum ; whereas those islands that are surrounded by a deep sea and considerably removed from continental masses invariably give an excess of gravity. The Barbados, in the West Indies, has about a normal value, which is just what we expect since it is neither surrounded by a deep sea, nor is it very near the South American Continent. Observations were made at St. Helena and Ascension both at the sea level and on the summit of the mountain. The work shows that the mean density of the whole island im both cases is considerably less than that of the rocks found on the surface, so that the attrac- tion of the mountain must in some way be compensated for by the internal structure or composition of its material. ArT. LIV.—On the Post-Glacial History of the Hudson Riwer Valley; by FRepERIcK J. H. MERRILL. From the post-Glacial deposits in the Hudson River valley may be derived much information as to the conditions prevail- ing therein subsequent to the retreat from its vicinity of the continental glacier. These deposits are of two general types: estuary formations of stratified clay and fine sand deposited in still water, and cross-bedded delta deposits of coarser material. They fringe the river shores in terraces between New York and Albany and indicate a long period of submergence, their present alti- tude above tide showing that the land has been elevated with respect to sea-level since their formation. Their materials were apparently brought mto the estuary by tributary streams which dropped the coarser particles near their mouths, while the finer rock flour was carried on in a state of suspension, and was finally precipitated to form beds of clay. From Albany westward spreads an alluvial formation which attains at Schenectady an altitude of about 340 feet aad extends through the Mohawk Valley in terraces which rise in altitude till they merge in the elevated beach plain of Lake Ontario at Rome about 405 feet above tide level. The origin of these terraces has not yet been determined. According to Mr. G. K. Gilbert the raised beach at Rome is that of a lake dammed by ice in the St. Lawrence Valley and flowing out into the Mohawk Valley, which carries its drainage into the Hudson estuary. According to this view the alluvial plain at Schenec- of the Hudson River Valley. 461 tady is the Mohawk delta, and the terraces of the Mohawk valley are stream terraces. Recently Mr. J. W. Spencer* has advocated the hypothesis that the raised beaches of the Ontario basin were formed at sea-level. In this case the Mohawk valley terraces would be estuary terraces homologous with those of the Hudson valley. An examination of these terraces is necessary to determine the point at issue. The delta of the Hudson River torrent has not yet been studied by the writer, but it will probably be found in the neighborhood of Sandy Hill. A general description of the estuary deposits of the Champlain Period in this region has been given by Professor W. W. Mather (Geol. Ist Dist. N. Y., pp. 148, 149). Between Poughkeepsie and New York the following streams have formed extensive delta deposits: Wappinger’s Creek near New Hamburg, Fishkill Creek, Quassaic Creek at New- burgh, Moodna River at Cornwall, Indian Creek at Cold Spring, Peek’s Kill, Cedar Pond Brook and Minisceong Creek at Hav- erstraw, Croton River, Pocantico River at Tarrytown, Sawmill River at Yonkers and Tibbit’s Brook at Van Courtlandt Park, New York City. The deposits of Peek’s Kill or Annsville Cove, as it is now called, are of considerable interest. ‘These names designate the basin which receives the waters of Annsville Creek, Sprout Brook, and Peekskill Hollow Creek, the last of which carries the drainage of several long and deep valleys trending to the northeast through Putnam County. About the margin of the basin are several terraces about 120 feet high showing charac- teristic delta structure and on the west bank of the Hudson opposite the village of Peekskill and immediately south of Jones’ Point is a terrace of coarse gravel which has the same altitude as those on the east bank and which was, at one time, regarded by the writer as a portion of the Peek’s Kill delta deposit. The coarseness of its material, however, would seem to preclude the possibility of this and to suggest that it origi- nated as a moraine or a kame and was subsequently terraced in the waters of the estuary. On the flank of Crow’s Nest Moun- tain near West Point the base of the terrace exposed in the railroad cutting is formed of bowlders of considerable size and it is suggested by Mr. G. K. Gilbert that this deposit was formed by a lobe of the retreating glacier. The estuary deposits of the Hudson River at New York indicate a post-Glacial depression of more than 70 feet. The terraces which border the west shore of Manhattan Island from * This Journal, vol. xl, p. 443 et seq. Am. Jour. Sci1.—THIRD SERIES; Vor. XLI, No. 246.—JuUNE, 1891. 31 462 LJ. A. Merrill—Post-Glacial History 75th street northward have a maximum height of 70 to 75 feet and on the New Jersey shore of the river, terraces of about the same altitude occur at frequent intervals. One of the most prominent of these is at Fort Lee, south of the steamboat landing. The surface material of these terraces is a fine sand or silt easily transported by the wind. It is evidently not a material which could be laid down in running water, for it would be carried in suspension by a river current and could only be precipitated in the still water of an estuary. North of New York City the altitudes of the terraces have been deter- mined at a few points as follows: Moutlrolf Croton -Biver 2202 3 100 feet. Peekskill oc. the oe ae eee ae 190 « West) Point 322 oo ie a ee 180 * Washkall: 2 03 pa ok ee A ene ge 250! see NchenectaGy, 214302 7. sae ee eee ee 340 “ A detailed measurement of the terrace altitudes between Fishkill and Schenectady has not yet been made. On the Long Island Sound shore of Westchester County, N. Y., the till which covers the metamorphic rocks has apparently been levelled off by wave action at an altitude of 75 to 85 feet. Plains of this character occur at frequent intervals, being separated by river valleys, and were probably formed during the depression which occasioned the estuary deposits of the Hudson River valley. These plains are composed of a modified till, obscurely stratified, somewhat sandy near the surface and comparatively free from bowlders, but unaltered bowlder clay or till oceurs at a few feet below their surface. On one of the most extensive of them the village of New Rochelle has been built. - 7 On Staten Island and western Long Island alluvial plains of stratified material rise gently from the ocean shore to the mar- gin of the moraine, terminating at an altitude of about 80 feet, and, though no continuous shore-line is to be found, the plains are referred provisionally to the same period as the estuary deposits a few miles north. From the evidence quoted the amount of the post-glacial depression at New York is estimated at about 80 feet. Whether this was subsequent to a greater depression of post- glacial date remains to be determined. In the estuary which occupied the Hudson River valley during the depression, there was deposited a great depth of plastic clay, evidently a sediment of aluminous rock flour produced by glacial attrition, and held in suspension by the post-glacial streams, and resting upon this clay, is a deposit of fine stratified sand. This bipartite character of, the Hudson River estuary of the Hudson River Valley. 463 formation suggests that two distinct conditions prevailed dur- ing the time of its deposition. The clay represents a period of still water deposition when little or no siliceous material was washed into the basin, while the overlying stratified sand was evidently deposited at a time when much siliceous matter was earried in by the tributaries. The causes of this differentiation are not clearly manifest. If there were good evidence to show that, at the close of the ice-period, there had been a greater submergence of the conti- nental margin than that proven by the delta deposits above mentioned, the hypothesis might be advanced that during this greater subsidence there was but little of the land surface ex- posed above sea-level in the vicinity of this estuary and conse- quently but little surface drainage. The larger tributaries fed by waters from the melting glacier would then bear into the estuary a large quantity of rock flour which would be held in suspension for a time and would finally be deposited in the deeper water as clay. As the land rose from its submergence, however, a larger area would be exposed to surface drainage and would yield in immediate proximity to the basin, an increasing amount of siliceous matter which would be deposited over the clay and constitute the upper member of the estuary formation. It remains for future investigation to determine the total amount of submergence in this region cotemporary with the last advance of the ice sheet and subsequent to its retreat. The records of ocean wave action are in many cases different from those of the extinct Quaternary lakes and not so easy to recognize. It is not always possible to decide a question of submergence by the presence or absence of a distinct shore- line. On a lake shore wave action tends to cut in an horizontal plane and the result is a series of terraces or a beach plane associated with shore drift and littoral deposits in various phases. When ocean waves act upon a shore there may be two cases : 1. The land may be at rest. In this case the result will be the same as on the shore of a lake which maintains its level for a comparatively long time. 2. The land may be rising or subsiding with respect to sea- level. In this case the plane of erosion will be a resultant of two planar forces: a, the wave force which operates in an horizontal plane; b, the force of elevation or depression which acts in a vertical plane and subjects to the former successively lower or higher portions of the land margin. According to the relation of these forces or the relation of the rate of land movement to the rate of wave cutting the plane of erosion will vary in its inclination. As the cutting rate relatively increases 464 L.. J. A. Merrili—Post-Glacial History the plane of erosion approximates to horizontality, and when it becomes infinitely great the plane of erosion will become a base-level. As the cutting rate relatively diminishes, the plane of erosion will become more and more inclined to the base- level and will approach verticality. When the cutting rate becomes infinitely small with respect to the rate of land move- ment the plane of erosion becomes vertical. In this case a vertical rock face would not lose its verticality by the erosion nor would the slope of the land surface be altered except through variations in the resistance of the rock acted upon. The degree in which the eroded land surface would approxi- mate to an oblique or vertical plane of erosion would depend upon the previous configuration of that surface. In order to completely discuss this question it would be necessary to con- sider a large number of incidental factors which might divert the plane of erosion from its theoretic position and prevent the eroded land surface from coinciding with it, but this complete- ness is unnecessary for the present purpose which is simply to point out the fact that a land surface in process of subsidence or emergence may be subjected to wave action without being incised with distinct shore lines, and also that wave action may produce an inclined plane as well as a terrace or a base-level. It is therefore evident that submergence would not leave a deeply cut shore-line as its record unless the rates of land movement and wave cutting were so adjusted as to permit of it. In fact, no very distinctly cut shore lines are to be found on the drift about New York even at an altitude correspond- ing with that of the Hudson estuary deposits. Apart from the still water deposits the 80 foot post-Glacial depression about New York can only be traced by change of surface slope and material at this level. Even these two varieties of evidence are not always co-existent. There are in Westchester County and on Long Island indi- cations of wave action on the glacial drift at altitudes of 150 to 180 feet, it remains to be determined whether they are reliable. The present condition of the Quaternary deposits in the Hudson valley is indicative of fluviatile erosion in post-Cham- plain time. ‘The estuary deposits and deltas have been eroded and truncated until but a narrow fringe is left of formations which once extended far across the valley or filled it, and the water in the channel of the river has now a depth varying from 50 feet in the shallower portions to 180 feet in the deepest parts. The delta deposits have also been subjected to the erosion of the streams which formed them and which developed cutting power as the land rose from its submergence. This erosion removed a large portion of the deposits and excavated chan- of the Hudson River Valley. 465 nels through them below present tide-level. The mouths of the tributary streams are now generally silted up and _the pro- cess of filling seems to be going on at present. It seems indisputable that the brick clay deposits once filled the entire valley up to a certain level, and that the present depth of the channel of the Hudson is due to the erosion of the still water deposits by a river current. It is also probable that in the narrow gorge of the Highlands some of the deltas filled the valley, but this point has not been fully determined. Between Poughkeepsie and Albany at many points near the water’s edge are steep, unglaciated rock surfaces much fresher in appearance than the glaciated surfaces upon which the Champlain deposits rest. These may be the result of river erosion subsequent to the formation of the terraces. The evidences of fluviatile erosion enumerated suggest a rapid flow of water down the Hudson valley in the late Quaternary. Such a flow doubtless began when the valley rose from its submergence. With these evidences of erosion may be correlated the gorge of the Narrows at the entrance of New York harbor. This is a gap in the terminal moraine about 240 feet deep and one mile wide at tide-level and there is no evidence that it could have resulted from non-deposition of the drift. The bottom of the present channel has a maximum depth of 100 feet below tide-level. It seems highly improbable that the present nauledbls channel of the Hudson could have been excavated to its present depth in the Champlain deposits by any agency except that of a river current,* and taking the maximum depth of the channel in the Narrows as an example of this erosion we have the amount of post-Champlain subsidence suggested as about 100 feet in the vicinity of New York. Observations on the coast of New Jersey and Long Island have well established the fact of recent subsidence which can be measured to the extent of 20 feet, by submerged tree stumps. The evidences of fluviatile erosion in the Hudson valley suggest that this may be not more than one-fifth of the total amount. From the evidence quoted it may be stated provisionally that after the retreat of the continental glacier from the Hud- son River valley, the land stood for a long time at a lower level than at present. What the maximum of depression amounted to is not known but in the vicinity of Albany the minimum depression amounted to about 340 feet and at New York to about 80 feet. Next occurred a gradual elevation of « the land amounting to about 180 feet at New York and at Albany to an amount undeter mined, but probably not less than * See J. D. Dana, this Journal, vol. x], p. 435. 466 W. Cross— Alunite und Diaspore 350 feet and perhaps 400 feet or more. During this elevation occurred extensive erosion of the Champlain estuary deposits in the river valley and subsequently followed a depression which has amounted to about 100 feet at New York and which is apparently continuing at the present day. As the land rose from its 80 foot depression at New York there seems to have been a brief period of less rapid elevation during which a second series of estuary terraces and alluvial plains were formed which now stand about 25 feet above tide-level. These have been recognized on Staten Island by Dr. N. L. Britton and may be seen on the Harlem River near Fordham Heights and at various points on the Long Island Sound shore of Westchester County. Art. LV.—On Alunite and Diaspore from the Rosita Hills, Colorado ; by WHITMAN Cross. THE occurrences to be described in this article lie between the mining towns of Silver Cliff and Rosita, in Custer County, Colorado. They were discovered while studying the geology of this region, under the direction of Mr. 8. F. Emmons, pre- liminary to a report which will appear as a monograph of the U.S. Geological Survey. In order that the geological interest attaching to the occurrences may be fully understood a general sketch of the local geology will be given. I. Geological Sketch of the Rosita Hills. The name Rosita Hills has been applied in the course of this work to a small group of rounded hills on the eastern slope of the great Wet Mountain Valley, which lies between the Sangre de Cristo and Wet Mountain [or Greenhorn] ranges, at a point south of the Grand Cafion of the Arkansas River. They cover an area whose dimensions are about five miles north and south, by four east and west, in which are small cones and smooth-sloped ridges, whose absolute elevations vary from 8,900 to 9,700 feet above sea-level, while the western and lower base of the hills is at 8,500 feet. The Rosita Hills are made up of volcanic rocks, while Archean schists surround them on all sides and constitute the floor upon which they rest, there being no sedimentary formations in the vicinity, except- ing local tufa beds. Upon the Hayden Geological map of Colorado, Dr. F. M. Endlich being responsible for this portion, the Rosita Hills are included in a much larger area of eruptive rock [* trachoreite,’ Endlich.], represented as extending along the base of the Wet Mountains, In this connection it may Jrom the Rosita Hills, Colorado. 467 not be out of place to state, for the information of those who have no grounds upon which to establish a personal opinion, that the term “trachoreite” of Endlich has no petrographical signification whatever. Almost all varieties of volcanic rocks known in Colorado—a long series—may be found prominently developed in areas mapped as “ trachoreite” by Dr. Endlich. The Rosita Hills are remarkable, when compared with other volcanic areas of the West, for the number of eruptions and the variety of products in so limited a district. Volcanic activity began, as indicated by the products seen, with an eruption of an andesite carrying hornblende and biotite. The action was explosive, for the product is wholly fragmental, consisting of mud, tufa, and breccia, now exposed in very irreeular relations. The vent is not known, and probably lies under some later flow. After erosion of the soft materials of the first period came two massive andesite outbreaks, one more basic, the other more acid, than the first. These overlap the earlier breccia on the north and south respectively, and form prom- inent cones and ridges. Succeeding these andesitic eruptions came a series of rhyo- litic outbursts. The earlier ones were violently explosive as shown by the agglomerate filling some of the vents, while the later ones were more quiet, producing massive rocks, seen in many short dikes cutting all the earlier andesites and the rhyolitic agglomerate, and in thin sheets on all flanks of the ils: cl ollowing the rhyolite came another andesitic magma, welling out through long fissures which cut all earlier rocks. Surface masses of the same rock are seen. It is a mica-augite andesite, with some free silica. The last important eruption produced a rock carrying a very slight excess of silica and having the characteristic structure and mineral composition of a trachyte. This magma came up through fissures some of which are nearly three miles long, and clearly traverse every rock that has been mentioned, excepting the dacite, which does not lie in their course. The later rocks of this series are in many places very fresh, while the older andesites are as a rule far gone in decomposition. This general decay is mainly due to thermal waters coursing through innumerable fissures. In these decomposed areas are many small, metal-bearing mineral veins. | The area whose volcanic history has thus been outlined is regarded by the writer as practically a voleano, whose phases were of very different character at different times. Four out of six important outbreaks produced massive rocks and but two were of the explosive character more commonly seen in true voleanoes. but the integral nature of the whole is ro) evident from the study of the mutual relationships of the 468 W. Cross—Alunite and Diaspore rock masses. Asa further proof that typical volcanic action has occurred here stand the masses of decomposed rhyolite which are to be described, for they can only be explained on the supposition that the rhyolitic outburst, known to have been of violently explosive character, was followed by a period of sulphurous gaseous exhalations whose products are identical with those of well known volcanic regions. There were two vents in particular which thus became true solfataras, and about them the rhyolite has suffered change into a rock-mass affording unusual resistance to atmospheric agencies and now forming rugged cliffs and projecting outcrops in a region of prevailingly gentle slopes and rounded contours. These two localities are in Democrat Hill and Mount Robinson, both situ- ated in the inner part of the group of the Rosita Hills. Il. The alunite rock of Democrat Hiil. Democrat Hiil is situated in the center of the Rosita Hills and in the acute angie between two gulches. It is of general rounded shape at the base, with a diameter of 1,500 feet and rises only 400 feet. On the north, or opposite the forks of the gulch, it joins on to a long ridge of andesite, and indeed all to the north is andesite, excepting later dike rocks, while to the south the prevalent rock is rhyolite, chiefly in the form of flows, some of which issued from the conduit below the hill. The upper three hundred feet of Democrat Hill stands out as a rough massive knob whose projections are somewhat rounded, though split by fissures and presenting occasional cliff faces. The color is slightly reddish and the whole presents a strong resem- blance to certain outcrops of massive granite. The lower hundred feet of the hill are covered by great angular blocks which have fallen from the cliffs above. A close examination of the rocks shows it to be cellular, the cavities being of irreg- ular shape and varying in size, with a maximum diameter of several inches, and an average of about one inch. The cells are lined by rudely tabular crystals some of which are com- posite and all are obscured by the minute quartz crystals deposited upon them. The mass of the rock is an irregular ageregate of imperfectly tabular grains of a mineral closely resembling orthoclase in luster, hardness, and general appear- ance. A pronounced cleavage runs parallel to the dominant planes of the tablets. The only other constituent of the rock is quartz, which forms a very evenly and finely granular mass between the tablets, and its grains are also abundantly included in the latter. A small amount of snow-white kaolinite is sometimes seen in the cavities. Microscopical examination of thin sections of the rock, and of cleavage flakes, shows the questionable mineral to be uniaxial, From the Losita Hilis, Colorado. 469 positive, and the cleavage is parallel to the basal plane. Sec- tions at right angles to the cleavage show stronger polarization than in feldspar, and sharp extinction parallel to the cleavage lines. The rough crystals in the cavities have the same optical characters, and the more perfect of them have a hexagonal outline caused by apparently rhombohedral planes. A chem- ical analysis of the average rock was made by Mr. L. G: Eakins, in the laboratory of the U. 8. Geological Survey, with the following results : : Molec. ratio. SHO gta 1: 65:94 NOME eae 1295 + 102 -127 3-26 Ee Opens i. 2°32 + 94 025). Ia Oe a9, 6p ve Pare SO cata. 12°47 + 80 156 4: Onc 4-47 + 18 -248 6-36 He Oeics 5 0°55 99:89 From the above figures it is seen that the constituents of alunite are present in very nearly the molecular proportion required for that mineral, with a slight excess of water and of bases. It is quite probable that there was a small amount of kaolinite in the material analyzed. The sulphate present is slowly soluble in H,SO,, and after slow roasting alum can be extracted with water. This rock then is made up of quartz, two-thirds, and alunite, one-third, aside from insignificant impurities. ‘The specimen analyzed seems to be representative of the entire upper part of the hill, though the percentages of quartz and alunite doubtless vary somewhat. MRhyolite occurs on the lower slopes about it and also underneath the summit of the hill, as shown by tunnels. A transition from rhyolite to alunite rock has not been observed at this place, but no good reason is known for doubting that rhyolite was the original rock here as at the other locality to be described. The observed limitation of the alunite rock in depth no doubt corresponds with the horizon at which sulphureted hydrogen gave rise to sulphurous acid on oxidation near the surface. Ill. Zhe alunite-diaspore rock of Mt. Robinson. Mt. Robinson is the highest point of the Rosita hills, although the summit is but six hundred feet above its southern base. Its slopes are smooth, owing to the soft andesitic material beneath, but the top is a projecting ridge, a quarter of a mile long, with a cliff of from fifty to seventy-five feet in height on the south, while a growth of aspens come close up to the crest on the north. The jagged crest is fifty feet or more in width, 470 W. Cross—Alunite and Diaspore and is made of a hard, rough, porous rock—a decomposition product, varying locally in character, but exhibiting in few. places any trace of the original rock structure. The crest rep- resents the extreme alteration. Along the base of the summit cliffs is a plain contact between spherulitic rhyolite and ande- site, and at either end of the crest the harder rock gives way to modifications showing spherulitic structure, and in one direction the body is continued for some distance as a distinct rhyolite dike, cutting through andesite. The rock composing the rough outcrops of the summit ridge is often much like the alunite-bearing mass of Democrat hill, and is in places identical with it, but it is much less uniform in character. Certain masses are composed of bluish cellular quartz, and barite appears developed in great irregular tablets in a few spots. On the whole, alunite is not developed in so large grains as in Democrat hill, and through the numerous minute quartz grains included in it the cleavage faces are less distinct, the result being a dull whitish or slightly yellowish rock of dense texture save for small irregular pores containing kaolin or yellowish ochre. A specimen of such rock from the eastern end of the crest, whose composition cannot be made out macroscopically, but which exhibits a large amount of alunite in thin section, was analyzed by Mr. Eakins and found to contain : Molec. ratio. Sistah ie 69°67 AOS nte 13-72 134 4:8 G1 igieens os ae 0°07 MD Dis 32 ti RSG 55. 2-44 “029 - ‘ar ae SR 0-34 Ee te Os eee boat 114 4-0 js Wo year era 4°73 263 9-4 L00°24 The alkalies present are but very slightly in excess of the amount required to go with the sulphuric acid to form alunite, while there is a considerable residue of alumina and water belonging to kaolin, the presence of which is shown by the microscope. The percentage of SO, found corresponds to 23°96 per cent of alunite. Toward the west end of the crest-ridge, and also near the middle, there is much of a rough, finely cellular rock consisting almost exclusively of bluish quartz and a transparent colorless mineral in irregular grains, noticeable on account of the bright luster on a very perfect cleavage plane. This mineral was at first supposed to be alunite in an unusually pure state. With % Jrom the Rosita Hills, Colorado. 471 this idea in mind, a specimen of the rock taken at the west end of the summit ridge was analyzed by Mr. Eakins, with this result : SLO Mae eM ee ASR! eh Ses FORO. AN TO AES 2 ak th can pag Pace be Onl NTO) Raya eds ae ok LAN bers 19°45 LEN OM EE vir Mee y ee ti (ENO) See Eee Se huietad Freeney amie ti AIISIIEE S Pa ag SEE Meet by renee tr. SOR tere ur eee cree sooo JF ONE AON aia ene Tih a iG 0°13 MI Onmere a pea es 3°82 100°02 The alumina belonged to a mineral insoluble in most acids, and infusible in alkaline carbonates. On treatment by hydro- fluoric acid, which dissolves the mineral with great difficulty, 17°79 per cent of this substance was isolated from the rock, and found to contain 84:67 per cent of AJ,O,, with no other base, while water was present in large amount. The theoreti- cal composition of diaspore is: AI,O, 85:07, H,O 14:93 = 100. Microscopical examination of the rock in thin sections, and of cleavage flakes of the mineral in question, showed it to possess the physical and optical properties of diaspore. By reason of its high refractive index its surface relief in thin sections dis- tinguishes it clearly from alunite, although both minerals occur in irregular grains in the rock mass and are filled by small included quartz grains. The alunite and diaspore of this rock having been determined in the spring of 1890, the writer revisited the region in the following summer, obtained further information concerning the occurrence, and collected specimens of particular interest. On carefully examining the material from a prospect hole sunk in the quartz-diaspore rock analyzed, some specimens were found containing irregular cavities an inch or more in diameter, in which were groups of rather stout prismatic, colorless or whitish crystals, with glistening faces, though seldom trans- parent. The crystals have several planes in the prismatic zone, and the low terminal planes which are clearly pyramids and domes indicate the symmetry of the orthorhombic system. Much of the surface rock at this end of the dike has cavities with similar crystals which are dull white in color and clearly much decomposed, the product being a fine micaceous mineral apparently kaolin. On the southern slope of the dike, below the summit, a few loose fragments of quartzose rock were found, with very bril- liant, clear, prismatic crystals, inclined to tabular development 472 W. Cross—Alumite and Diaspore through the prominence of a pinacoid. While these various forms were thought to belong to a single mineral, the species was not recognized in the field. By measurements, on a small Fuess goniometer, the mineral was, however, readily identified erystallographically with diaspore, and the faces determined as follows: oP, prominent in all crystals; oP2, the most prominent prism; o P, narrow; P2, broad, good faces; unit pyramid, P, narrow; P&, occasionally distinct. As this seems to be the first known occurrence of diaspore in any such connections, and also on account of the rarity of this erystallo- graphic development, the writer requested Dr. W. H. Melville to examine the material carefully, and if the result warranted it, to present the crystallographic data, with figures, in a special article. This he kindly consented to do, and his report will be found in the paper succeeding this. A small clump of clear crystals was analyzed by Mr. Eakins with this result : ALOL ORAS ree) tee 83:97 EL ORs Ce a 15°48 99°40 The results of the erystallographical and chemical examinations thus place the identity of the mineral with diaspore beyond question. Further data as to the occurrence will be given in discussing the origin of these minerals. IV. Alunite pseudomorphs. At the western base of the Rosita hills a shallow prospect shaft has been sunk in a brecciated quartzose vein matter, which is the alteration product of the country andesite on a line of fissuring. Near by isa large dike of altered rhyolite, the specimens from it which have been examined consisting of kaolin and quartz. The shaft has long been abandoned and is inaccessible. Its dump shows mainly quartz vein matter through which some pyritiferous ore is sprinkled. One small part of the dump is made of bluish quartz breccia, the spaces between angular fragments being lined by crystals. There is first a coating of minute quartz prisms, then in some cavities larger quartzes with rough prismatic and smooth pyramidal faces. In a portion of this material there are numerous tabular crystals, and, of deci- dedly later age, kaolin, or ochreous limonite, in a few specimens. The tabular crystals referred to are dull white, opaque, with rough surfaces, yet showing distinct crystal form. ‘The faces are to be interpreted as unequally developed positive and nega- tive rhombohedrons, combined with a dominant basal plane. In size these crystals average 0°5™ in width, by a thickness of from the Rosita Hills, Colorado. 473 jam An examination with a hand lens shows that the crystals are for the most part irregular granular aggregates of some mineral possessing a distinct cleavage. This is especially clear on fractured surfaces by the irregular positions of the cleavage planes. In some of the thicker crystals, broken through the center, is seen a clear glassy kernel of a colorless mineral, and its position immediately suggests that it represents the original substance of the crystal, of which the granular aggregate about - it is a pseudomorphic alteration product. Some of these white crystals, carefully detached, but sup- posed to include the points of some of the quartz crystals upon which they were deposited, were given to Mr. Kakins for analysis. He found: | Molee. ratio. RIO) SS sk 38-91 381 3°49 KO ees 4°03 ne Och nae “118 101 SOR tcc 35°91 446 4-00 © Hee 13203 724 6°49 CAO MCE ce 0°35 DIO) eset 2°82 Mic Ore aa ty 99°37 Tests showed that the silica came chiefly from included quartz grains. The remaining constituents, aside from the small amount of lime, are those of alunite, and by the usual calculation it is seen that they are present in the required ratio for that mineral, with a slight excess of water and of alumina, which can be referred, with a portion of the silica, to admixed kaolin, an observed associate of the crystals. The unexpected result of the analysis was followed by a microscopical examination of thin sections prepared parallel to the basal plane of several crystals, and normal to that plane in a crystal with a glassy kernel. The fresh core possesses a cleavage parallel to the basal plane of the crystal, and its optical properties seem to be throughout those of alunite. The outline of the kernel isirregular. About the fresh alunite kernel is an aggregate of irregular particles, arranged without reference either to the outer crystal form or to the inner core. Those grains which are decidedly elongated polarize brightly, have sharp lines of cleavage parallel to the length, and the direction of major elasticity is always parallel to the cleavage lines. Many sections are not so elongated, and these polarize less brightly, some giving only gray tones, while a few are almost isotropic. The latter show a positive interference cross in convergent polarized light. 474 W. Cross—Alunite and Diaspore, ete. The facts which have been given seem to prove that the crystals in question are pseudomorphs of alunite after itself. An explanation of this anomaly is suggested by the volcanic history of the district. The crystals are almost certainly the result of solfataric action connected with the occurrences al- ready described. If we suppose those alunite crystals to have been replaced by some other mineral, in which the bases were retained, a renewal of solfataric activity would naturally con- vert them into alunite again, but the protected cores of the original mineral could not influence the orientation of the new generation. V. Origin of the rocks described. In all of its observed occurrences alunite is a secondary product due to the action of sulphurous or similar acids upon highly aluminous rocks, yet there are two very different sites, with different attendant conditions, in which this action takes place. In the one case, the rock belongs to a clay bank and the acid is derived as a rule from the decomposition of marecasite in or adjacent to the clay. The product is a dark dense amorphous mass. In the other case, the agent is the sulphurous exhalation of a solfatara, and the rock acted upon is usually volcanic and rich in alumina and alkali—such a rock as rhyolite or trachyte. The product of this action is com- monly a hard, rough, porous, highly crystalline rock, though a dense amorphous mass is often locally developed. | The alunite rock which has been described is directly com- parable with the classic solfataric occurrences of Bereghszasz in Hungary, the island of Milo, and La Tolfa, near Rome. The writer has been unable to find mention of any similar occurrence on the American continent, and, judging from the descriptions given by von Richthofen* and vom Ratht of other localities, the rock of Democrat hill is remarkable for its purity, homogeneity and extent. Exactly similar material is not described by the authors named. The limits of this article forbid any further comparison of occurrences or discussion of the processes involved in the formation of alunite, which are reserved for the monographic report upon the geology of the district. While the alunite may be assumed to have been formed by the same processes which are involved in other cases, the dias- pore of Mt. Robinson has apparently originated under condi- tions very different from those of any other known occurrence. * In ‘Studien aus den ungarisch-siebenbirgischen Trachytgebirgen ” Jahrbuch d. k. k. geol. Reichsanstalt, xi, 254-268, Vienna, 1860. + Mineralogisch-geognostische Fragmente aus Italien. IV. Das Bergland von Tolfa. Zeitschrift der devtschen geol. Ges., xviii, 585, Berlin, 1866. W. H. Melvitle—Diaspore Crystals. 475 Its genesis, when in the ordinary association with corundum, emery, margarite, and other minerals, can have little in common with the present case. It has never been reported as an associate of alunite, nor as a decomposition product of eruptive rocks. The only previously observed occurrence connecting diaspore in any way with eruptive materials was recently mentioned by A. Lacroix,* who identified it as a minor constituent of a single block of gneiss, enclosed in a basaltic tufa of the Auvergne. This block is composed mainly of garnet, quartz, orthoclase and oligoclase, with rutile and diaspore, and is considered by Lacroix as an ejected fragment of a much metamorphosed rock, like many others in association with it. He does not refer to the novelty of this occurrence for diaspore, nor discuss its origin. There is but little evidence upon which to formulate a theory as to the origin of the diaspore of Mt. Robinson, but after study of the specimens, it seems to the writer probable that it is here a result of the destruction of alunite At .La Tolfa, alum is obtained by the slow roasting of the alunite rock, after which water extracts the soluble sulphate, but there is a residue of insoluble hydrate of alumina. Should this roasting and leaching take place in nature, it seems quite likely that subsequent conditions might lead to the crystalliza- tion of the residue as diaspore, making a porous quartz-diaspore rock. Some further agency would seem to be required to explain the occurrence of diaspore crystals in the cavities. Art. LVI.—Diaspore Crystals ; by W. UH. MELVILLE. THE crystals of diaspore, which Mr. Cross submitted to me for examination, present two types of combinations of planes referable to the prismatic or orthorhombic system of axes. One type consists of light brown transparent crystals which are elongated m that direction commonly chosen as the vertical axis, and which exhibit a largely developed brachypinacoid plane invariably much striated. This latter characteristic is true though to a less extent for the narrow prismatic planes. The erystals are doubly terminated, and are implanted in the associated rock upon one set of prismatic edges. A drawing of these crystals would resemble that given in Dana’s Mineral- ogy, fifth edition, page 168, fig. 173. The following forms were observed.t * “Sur Vexistence d’une roche a diaspore dans la Haute-Loire.” Bul. Soe. fran. de Min., xiii, p. 7, Jan., 1890. + The symbols given are those of Miller and of Naumann as modified by Dana. 476 W. Hf. Melville—Diuaspore Crystals. Brachypinacoid. Brachydome. [100], iz [120], 2-2 [101], 1% Prisms [340], je Pyramids 7 [111], 1 _ [110], I [670], t= [22a In the zone circle [111, 122] the mean of the most accurate measurements are given®* under I, and another series under II. In almost all cases the signals reflected from the brachypinacoid were duplicated, so that it was often necessary to calculate the angle which this plane made with its adjacent planes from the difference of the sum of the other angles in the zone and 180°. Measured. ae *K okscharof. 100 411] 63° 7 63° 204 63° 5d Leta a 122 2G 414 12° 44 12°40 122.0122 28° 23 28° 23 28° 29 129 Ait 12° 414 12° 39 12° 40 111.100 63° 7 63° 214 68° 54 180° 180° 287 In the zone [100, 101] the measured angles were 100A 101 = 58° 50’ (1) and 58° 54’ (2); mean 58° 52’. For this angle Dana gives 58° 525’ and Marignac 58° 53’. The following are the mean of the most reliable angles obtained in the zone of prisms : 100.110 46°54} 110,670 4°22 670,340 3° 74 340.120 10° 203 120.120 50°31 The axial ratio was calculated from the angles 100,110 = 46° 54$ and 100A 101 = 58° 52. a:6:¢ = 06457 : 1: 10689 found. = 0°64425: 1: 1°067 Dana. The second type consists of crystals which are white and almost opaque. ‘They are stout and often pre- sent a pyramidal habit, as they are imbedded in the rock, resulting from the combination of the prism (120) and the octahedron (122). The annexed figure illustrates this habit of diaspore, and is drawn from a crystal which was removed from the rock and measured. The dominant forms are (120) and (122), while a macrodome (011), the brachypinacoid (100), and the octahedron (111) appear as small sec- ondary planes. The crystals rarely show more than can be seen in the drawing, because they have grown into each other forming dense aggregates. The following angles were ob- tained from this crystal : * The angles between normals are given in all cases. R. W. Wood, Jr.—Combustion of Gas Sets. 477 Between normals. Between normals. 100 A111 64° 5 approximate. 122 2 120 54° 26 excellent. 1114122 LO 3 te 122 . 120 54° 17 Bb DD 22, 28° 20 excellent. 120 2 120 50° 7 It is apparent from the foregoing tables that the crystals under discussion do not differ essentially in crystalline habit from those of the same species previously described by other mineralogists. (The slight differences in the recorded measure- ments must be due to the imperfection of the surfaces from which the light is reflected. Reflected images of the shit of the goniometer have been frequently observed superimposed upon each other, and differing in position by two and three minutes. Errors arising from this source have been elim- inated to a great extent in my tables of measurements. by the choice of the mean value of many observations. Chemical Laboratory of the U. S. Geological Survey, Washington, D. C., Feb. 24th, 1891. j Art. LVIL—Combustion of Gas Jets under Pressure; by R. W. Woop, JR. Any one who has watched a burning jet of ether vapor has probably noticed that, as the pressure increases, the flame gradually retreats from the orifice, hovering in mid-air, as it were, and eventually goes out, if the pressure be carried beyond a certain point. In endeavoring to discover the exact cause of this, a number of rather curious phenomena were observed. Different gases were experimented upon, and found to act in very different ways, dependent apparently upon the relative amounts of oxygen required for their combustion. The first experiments were made with coal gas, with pressures varying from 0°5 to 25°* of mercury. The gas was drawn from a large reservoir, used for supplying an oxy-hydrogen lantern, at a tension of about ten pounds to the inch, the pres- sure at the jet being regulated by a stop-cock and measured by an open U-form mercurial manometer. With an orifice 1™™ in diameter, the following were the results obtained under varying pressures. Pressure 06°"*—A quiet cylindrical flame, like a candle, 17™: high (fig. 2 A). Pressure 1™—Flame 26™§ high. Pres- sure 1:4™—Flame 38% high, still quiet and tapering to a fine point ; this pressure gave the maximum illuminating power to the flame. On increasing the pressure, the flame suddenly shortened, diminished in luminosity, and vibrated considerably, emitting a slight roaring sound which increased with the pres- Am. JOUR. ScI.—THIRD Series, Vou. XLI, No. 246.—JuneE, 1891. : 32 478 Lt. W. Wood, Jr.—Combustion of Gas Jets. sure. Pressure 2°*—Flame reduced to a height of 20™5; hissed perceptibly. Pressure 3°™*—Its length about 17’; it roared loudly, and a contracted place appeared 4%™* from the orifice, fig. 2 B). Pressure 5°™S—F lame reduced to 15°’, the contraction approached within 1:7 of the orifice. Color, blue for the most part, a little yellow at the tip, very little luminosity. Ki | f —= Pressure 7™*—Yellow tip all gone; small broken spaces ap- peared in the flame beyond the contraction ; resembled the flame of a Bunsen blast lamp and was about as hot; glass could be worked in it as easily as in the blowpipe flame (fig.2 c). Pres- sure 10°*®—A large break appeared in the flame just beyond the contraction; the flame beyond united with that below by a mere thread (fig. 2D). Pressure 11°™*—Flame beyond the break alternately went out and relighted with a snapping noise, showing that it was an explosive mixture of gas and air. R. W. Wood, Jr.—Combustion of Gas Jets. 479 Pressure 12°*—Flame beyond the contraction went out, and there was left only a short tube of blue fire, as sharply defined as if made of rigid matter (fig. 2 £). Through this tube a vast quantity of unconsumed gas flowed, which was so cold that the eye could be brought directly over the tube, when it was seen to be distinctly hollow, with thin sharply defined walls. Pressure 20™s—Tube shortened to one-half its former length, and the walls became thinner (fig. 2 F). Pressure 23°™°—The tube went out. The formation of the tube is a rather curious phenomenon. It appears to be due to the fact that the gas molecules on the outside are moving slower than those within, the speed being reduced by friction with the walls of the orifice. What we have then is a jet of gas moving at high speed surrounded, below the contracted place (where the air mixes with it), by a shell of gas moving at a velocity so low that it will remain ignited ; with an increase of pressure we should expect the shell to become thinner, and this is exactly what happens. Burning the gas in oxygen, the jet will stand a far greater pressure without forming a tube or blowing itself out. In fact it is difficult to raise the pressure high enough to bring this about. Were we dealing with a flame of pure hydrogen, burning in an atmosphere of oxygen, it would be impossible. Any one who has used the oxy-hydrogen blowpipe knows that it is impossible to give a velocity to the mixed gases great enough to extinguish the jet. The rate at which fame will run down such a jet, or rather the rate at which combustion takes place through a mixture of two parts of hydrogen and one of oxygen is 2500 meters (more than a mile and a half) a second. That is to say, if we had a tube a mile and a half long filled with the mixture, the flame would traverse it in one second. The explosion would be practically instantaneous. Contrast this with coal gas and air. Filla glass tube a meter long and an inch in diameter with a mixture consisting of 1 part of coal gas to 10 of air. Apply a flame to the open end, and a dise of blue fire will descend the tube with a whistling noise at the rate of about 18 inches a second! The reason why the jet of coal gas blows itself out is very obvious; its velocity is greater than 18 inches per second, consequently it carries the flame away, so to speak. ‘To cause an oxy-hydrogen jet to act in a similar manner we should have to give it a velocity greater than 2500 meters a second. To determine the exact form of the jet when not ignited, the gas was passed through two bulbs, each filled with asbestus, that in one bulb soaked with ammonia, in the other with hydrochloric acid. The gas, passing through these bulbs, became charged with dense white fumes of ammonic chloride, which rendered the jet plainly 480 R. W. Wood, Jr.—Combustion of Gas Jets. visible. At a very low pressure, too small to be accurately measured by the manometer (say about 0°1™), the column of gas rose unbroken like the smoke of an extinguished candle (fig. 1 A), and a burning match applied to the top of the column would ignite the jet, the flame running down to the orifice and burning quietly there. On blowing out the flame and increas- ing the pressure a little, the column broke into a fan at a definite height (v, fig. 1 B). Below this point, the regular out- line was preserved, but above it the gas diverged rapidly in whirling masses. To ignite the jet permanently, it was now necessary to apply flame below the point V. If applied above, the gas beyond the match burnt with a roaring blue flame, which went out the instant the match was withdrawn, or if the ve- locity was not too great, hung for a few moments in mid-air, The point V, where the divergence commences, is evidently the point where air is being mixed with the gas. Increasing the pressure brings the point nearer and nearer the orifice, until finally there is scarcely a trace of the unbroken column. Let us now consider why it is necessary to bring the flame below V in order to ignite the jet permanently. Above this point there is a mixture of gas and air, which is moving at a rate considerably greater than 18 inches per second, conse- quently the flame is carried up by the jet faster than it can run down. Below the point V we have a stream of undiluted gas, down which the flame will travel rapidly enough to keep the jet permanently lighted, for then the gas above V will be kept lighted by the flame below. What we should expect would be a quiet cylindrical yellow flame below V, and a roaring, flaring, blue flame above, but this is not what happens. On bringing the match below the point of divergence, the burning mass above ceases to flare, and the whole subsides into a quiet tapering yellow fame. ‘The pressure may be increased some centimeters before the tip begins to flare and burn with a blue flame. The reason for this is not very obvious.. Lgnit- ing the jet appears to bind it together and prevent entrance of alr. With an ordinary four-foot bat-wing burner the best flame was given by a pressure of about 13° of mercury. A pressure of 2°* gave a quiet flame, but there were lateral horns at the bottom. At 6™* the luminosity was greatly diminished, wide horns formed, and radiating streaks appeared in the blue part. At 12° the luminosity was nearly gone, and a dark arch of unconsumed gas appeared above the orifice, fig. 3.. A pressure of 20°. widened this arch, and rendered the flame non- luminous. At 25°™* the flame blew itself out. These experiments were repeated with ether vapor, the pressure being derived by boiling the fluid. Owing to the Rk. W. Wood, Jr.—Combustion of Gas Jets. 481 rapid condensation, considerable difficulty was experienced in keeping the pressure uniform during the observations. The tubes leading from the flask to the manometer had to be kept hot in order to prevent fluid ether instead of vapor from being delivered at the orifice, which in this case was smaller, being about the size of a small sewing needle. With coal gas this jet would stand a pressure of 20°* without going out. With ether vapor 4 of a centimeter gave a flame like a candle, while 4™ caused the flame to retreat about a centimeter from the orifice and burn in mid-air. At “4™ pressure the distance had widened to four centimeters, and the vaporized ether could be seen rising as a cylinder the size of a knitting needle surmounted by a hollow blue flame, fig. 4. At 1°" pressure the flame went out! It behaved very much as coal gas did when burnt in bad air, the flame showing no tend- ency to form a tube under increased pressure. This seems to be due to the fact that ether vapor requires a greater amount of oxygen for its combustion. In pure oxygen it behaves very much as coal gas does in air. Alcohol vapor comes between the two, the flame standing a pressure of about 3°™* without being extinguished, and showing a tendency to form a tube. The nature of these flames was studied with a revolving mirror, but no interesting features were revealed except in the ease of the coal gas under high pressure. The action of the rotating mirror is to spread out the flame in a broad band, giving as it were an infinite number of instantaneous views, placed side by side. If the upper parts of the jet move slower than the lower, they will suffer lateral displacement, and the flame images will be curved backwards. The flame shown in fig. 2 c when examined in the mirror appeared as in fig. 5. The serrated part of the flame represents the contracted por- tion, and the alternate dark and light spaces show that this part of the flame alternately ignites and goes out, with sufficient speed, however, to keep the gas above in a state of continuous combustion. The long narrow band below is the burning tube of gas, and the bright teeth are rapid flashes of fire uniting this with the burning mass above. Under greater pressure the frequency of these flashes becomes reduced to such a degree that they are appreciable to the eye. This is the case in flame D (fig. 1). Here the upper portion alternately ignites and goes out with a rapid snapping noise, the pulses varying from one to ten asecond. In the rotating mirror this flame presents the appearance shown in fig. 6, the flashes being so slow that they are completely isolated from each other by the mirror, each one being seen as a broad flare of light. The line representing the tube of fire is narrower now, the pressure being greater. co) The slanting base of the “flare” is bright blue, above this is a 482 M. Carey Lea—Allotropic Silver. faint green tinge, while still higher we find the lirht purple tint of the Bunsen flame. The appearance of this flame in the mirror clearly indicates what is taking place. The mass of gas above the contracted place, after being ignited by a flash from the continuously burning tube, does not immediately go out. The flame fights its way down the ascending column, but con- tinually loses ground, owing to the great velocity of the jet. The second flash comes often before the tip of the first one has gone out, and if the interval is short enough the flashes will mingle. In fig. 7, I have attempted to show this in a clearer manner. The series shows an interval of one flash, the figures representing instantaneous views of the flame at successive moments of time. Figs. A to E show the gradual dying out of the flame of the first flash. At F the second flash has com- menced, and at H it has risen and mingled with the last vestige of the first. By carefully regulating the pressure, we may give to the jet a velocity which shall equal the speed of combustion for the mixture of gas and air. The flame will now hang balanced in the air, as shown in fig. 8, the tendency of the fire to spread downward being exactly neutralized by the upward motion of the column. On examining this flame the cause of the bright blue and faint green lines in the mirror is discerned. Around | the base of the flame the mixture burns with an intense blue light (fig. 8 A); surmounting this is a cone of greenish fire B, while above this the flame has a light purple tinge. Art. LVIIL—Allotropic Silwer. Part Ill. Blue Silver, soluble and insoluble Forms; by M. Carey LEA. WHEN my first paper on the subject of allotropic silver was published about two years ago, that substance seemed to be the result of a very limited number of reactions closely allied to each other. Further study has shown that it is a much more common product than at first appeared to be the case. Wher- ever in the reduction of silver a reddish color shows itself, that may be taken as a probable indication that allotropic silver has been formed, even although it may be destroyed before it can be isolated. | What is rather remarkable is that allotropic silver is pro- duced abundantly in certain very familiar reactions in which its presence has never been suspected: so abundantly in fact that some of these reactions constitute the best methods of obtaining silver in the soluble form. In photographic opera- tions silver has often been reduced by tannin in the presence M. Carey Lea—Allotropice Silver. 483 of alkalies. It has not been imagined that by slightly varying the conditions, the whole of the silver may be made to pass into solution as a soluble metal with its characteristic intense blood red color. . Some of these new reactions will be here described in detail. Allotropic Siluer obtained with Dextrine and Alkaline Hydroxide. When dextrine is dissolved in a solution of potassium or sodium hydroxide and silver nitrate is added, keeping the hydroxide in moderate excess, the silver is at first thrown down in the form of the well known brown oxide. This brown color presently changes to a reddish chocolate shade and at the same time the silver begins to dissolve. In a few minutes the whole has dissolved to a deep red color, so intense as to be almost black. A few drops poured into water give it a splendid red color of perfect transparency. Examination with the spectroscope leaves no doubt that we have to do with a true solution. It is interesting to observe that silver can be held in solution in neutral, acid and alkaline liquids. In the first process which I published, in which silver citrate is reduced by a mixture of sodic citrate and ferrous sulphate, the latter may be used either in acid solution or it may be first neutralized with alkaline hydroxide, so that that form of silver is held in solution in either a neutral or an acid liquid. The form that is obtained with the aid of dextrine dissolves most freely in the strongly alkaline liquid in which it is produced, and when dilute nitric or sulphurie acid is added the silver is precipitated. But with acetic acid the precipitation is very incomplete: the solution retains a brown color and contains silver. Even the addition of a large excess of strong acetic acid fails to throw down any more silver. It follows therefore that while this form of silver is most freely soluble in a strongly alkaline liquid it is also soluble to some extent in one that is either neutral or acid. The precipitate when once formed appears to be almost insoluble. A small portion of it stirred up with distilled water gives no indication of solution. But if a quantity is thrown on a filter and washed, as soon as the mother water is washed out the liquid runs though of a muddy red, and if this filtrate be allowed to stand it deposits an insoluble portion and then has a fine rose-red color and perfect transparency. Not- withstanding the beautiful color it contains a trace of silver only, so great is the coloring power of the metal. Sometimes if the alkaline solution stands for a month or two the silver. becomes spontaneously insoluble; most of it falls to the bot- tom as a deep red substance, but part remains in suspension j 484 M. Carey Lea—Allotropic Silver. with a bright brick red color. The difference between this and the true solution as originally formed is extremely well marked. , Dextrine is a very variable substance and different speci- mens act very differently. Common brown dextrine seems to do better than the purified forms. Convenient proportions are as follows: in two liters of water forty grams of sodium hydroxide may be dissolved and an equal quantity of dextrine, filtering if necessary. Twenty- eight grams of silver nitrate are to be dissolved in a small quantity of water and added by degrees at intervals. Com- plete solution readily takes place. Although the liquid con- tains less than one per cent of metallic silver it appears absolutely black, when diluted, red, by great dilution yellowish. With some specimens of dextrine the solution remains clear, with others it soon becomes a little turbid. Perhaps the most interesting reaction which this solution shows, is that with disodic phosphate. A little phosphate is sufficient to throw down the whole of the silver although both solutions are alkaline. When a gram of phosphate in solution is added to 100 c.c. of silver solution the color becomes bright red, sometimes scarlet, and the whole of the silver is presently precipitated. This precipitate on the filter has a color like that of ruby copper, which color it retains during the first washing, but after a few hours’ washing with distilled water the color changes to a deep Nile green and at the same time it becomes slightly soluble, giving a port wine colored solution. With more washing this solubility may disappear. It is a general fact that all these forms of silver, however various their color, have both a body and a surface color and these two colors tend always to be complementary. The body color is that shown by the precipitate while still moist; it is also visible when a thin coat is brushed over paper, a coat so thin that light passes through it, is reflected by the paper and returned again through the film. but when a thick and opaque film is applied, the body color disappears and only the comple- mentary surface color is visible. | So in the case of the precipitate by phosphate, when the substance resembling ruby copper is spread thickly on paper it dries with a bright green metallic surface color. But when the substance itself beeomes green by continued washing it assumes on drying a dark gold or copper color, the surface color changing with the body color and maintaining its com- plementary relation. In observing these effects one is con- stantly reminded of certain coal tar colors, both by the great intensity of coloration and by the metallic surface color. Iam M. Carey Lea—Allotropie Silver. 485 not aware that any other inorganic substance shows this resem- blance to a similar extent. These forms of allotropic silver have a great tendency to attach to themselves foreign matters. Although the dry sub- stance has all the appearance of a pure metal it may contain as much as 8 or 10 per cent of organic matter which it is utterly impossible to detach. I have taken much trouble to eliminate this substance. In one attempt hot distilled water was forced through with the aid of a filter pump for over 100 hours with- out effect. The presence of this organic substance becomes evident when the metal is heated ina tube. A vapor arises which condenses into small brownish drops having an empy- reumatic odor. The residue of bright white metallic silver, when dissolved in nitric acid, leaves behind black flakes of carbon. When the allotropic silver is dissolved in dilute nitric acid and the silver precipitated by hydrochloric acid, on evapo- ration a small residue of a yellowish gummy substance is ob- tained. Analyses.—Four silver determinations were made of mate- rial rendered as pure as it was found possible to obtain it. Results— IN ORES Baise ne ey DBT (Ds GO, Ais INO ROU Mai Ses SHINGO Air 8) es INGO: one ais oy G2ESGr Sas INGos aig Sota ieee is «i 96°64 “* 2 Allotropie Silver obtained with Tannin and alkaline Carbonates. Tannin (gallotannic acid) in alkaline solution reduces silver nitrate to metallic silver in the allotropic form. Tannin acts more strongly than dextrine and therefore does best with car- bonated alkali, dextrine best with alkaline hydroxide, although either substance will produce the reaction with either form of alkali and, though less advantageously, with ammonia. Tannin with sodium carbonate gives a very perfect solution of silver, quite free from the turbidity that is apt to characterize the dextrine solution. The color of this solution is likewise very intense: one containing one per cent of silver is quite black, by. dilution deep yellowish red. It has very much the same characters as the preceding, but is rather more stable. To obtain it, 24 grams of dry sodium carbonate may be dis- solved in 1200 cc. of water. A 4 per cent solution of tannin is to be made and filtered, of this 72 cc. are to be added to the solution just named: of silver nitrate, 24 grams dissolved in a little water are to be added by degrees. Solution takes place almost instantly as each successive portion is added. The solu- tion after standing a day or two may be decanted or filtered trom.a small quantity of black precipitate. 486 M. Carey Lea—Allotropic Silver. When the solution is treated with a very dilute acid, as for example, nitric acid diluted with twenty times its bulk of water, allotropic silver is precipitated in the solid form. It dries with a brilliant metallic surface color of a shade different from the foregoing and somewhat difficult to exactly charac- terize, a sort of bluish steel-gray. I do not find that blue allotropic silver (in which is included the green and steel-gray varieties) can be reduced to any one definite type. On the contrary, its variations are endless. Slight differences in the conditions under which the solutions are formed or in the mode of precipitation give quite different products. For example, of ten products obtained with tannin and sodium carbonate in different proportions, several were easily and completely soluble in ammonia, some were slightly soluble and some not at all. Some specimens not at all soluble in water became so by moistening with dilute phosphoric acid : they did not dissolve in the acid but when it was removed they had become soluble in water. On other specimens phosphoric acid had no such effect. Some solutions are scarcely affected by acetic acid. others are partly precipitated, others almost but not quite wholly. The films spread on paper vary very much in their relations to light ; some are readily converted into the yellow intermediate form, whilst others are very insensitive. The least sensitive specimens seemed to be those for which dilute nitric acid had been used as a precipitant. They had a steel-gray color. Precipitation by acetic acid seems to tend to a greenish metallic surface color and greater sensitiveness. Different specimens also vary very much as to permanency; this character is also affected by the amount of washing re- ceived: thorough washing tends to permanency. In some way the blue, gray and green forms seem more closely related to the black or dark gray forms of normal silver, for they tend in time to pass into them, while on the contrary, gold-colored silver, if pure, tends with time to change to bright white normal silver on the surface, with dark or even black silver underneath. Action of other Carbonates. Tannin is capable of producing allotropic silver, not only in the presence of the carbonates of potassium and sodium, but also with those of lithium and ammonium and also with the carbonates of calcium, magnesium, barium and strontium. The action of the last named carbonate has been more particularly examined. It yields allotropic silver of a dark red color while moist, drying with a rich bluish green metallic surface color in thick films, in very thin films transparent red. It is probable M. Carey Lea—Allotropic Silver. 487 that the substances with which tannin produces these reactions would be further increased by investigation. I have found some additional modes of production of these forms of silver, modes which are very curious and interesting. They are now being studied and will be reported on hereafter. Nature of the “ intermediate substance.” It has been mentioned in previous papers that when allo- tropic silver is converted into normal silver by the action of heat it passes through a perfectly well marked intermediate state. In this state it retains the gold-yellow color and high Inster but none of the other properties of the original form. Oxidizing and chlorizing agents show nearly the same indif- ference as with ordinary silver. While allotropic silver is soft and easily reduced to powder the intermediate substance is hard and tough. When a glass rod is drawn over a film of allotropic silver it leaves behind it a white trace of ordinary silver. The intermediate sudstance shows no such reaction : the trace of a glass rod does not differ from the rest of the film and even hard burnishing produces nochange in the color. Continued exposure to sunlight brings about the same altera- tion to the intermediate form and it takes place spontaneously with time. At that time no explanation could be found as to the nature of the change. It proves however to be a passage into a erys- tallime form. Some films spread on paper were exposed to the action of very dilute solution of ferric chloride. It chanced that one of these films had undergone a partial change into the intermediate form; the unchanged portion was darkened by the ferric solution, while the portion that had passed into the intermediate form retained its bright gold-yellow color‘and luster, rendering it thus distinguishable. The figures which it exhibited were strikingly crystalline. One portion showed a foliated structure such as is formed by interpenetrating crys- tals, other parts showed ramifications with something of a plant-like form. Another part exhibited a sheaf of acicular crystals nearly parallel in direction, half an inch to an inch iong and as fine as hairs. These appearances indicated with certainty crystalline structure. Other specimens have been obtained though none so well defined as that just mentioned which happened to be taken at exactly the right stage of spon- taneous alteration to make the structure manifest. The altera- tion is not apparent to the eye as the color does not change. This change to the crystalline condition does not seem to be peculiar to gold-colored silver. The blue form when gently heated in a tube becomes yellow. By continued heat it changes to white normal silver. A film on glass began to 488 M. Carey Lea—Allotropic Silver. change from blue to yellow at about 180° C. Light also pro- duces this change on blue silver. The specimens obtained by different processes act very differently; some change with a few hours of strong sunlight, others require many days. From what has been written in this and preceding papers it appears that allotropic and even soluble silver may be formed in a great variety of reactions. The reducing agents may be either a ferrous or a stannous salt or any one of a variety of organic substances of very different constitutions. From the solubility and activity of this substance and the parallelism which many of its reactions show to those of silver in combi- nation, I have been disposed to think that silver in solution might, like silver in combination, exist in the atomic form. It is certain that up to the present time we have no positive knowledge of the existence of any element in the atomic form as a solid. We know that four or five metals are atomic in their vapors and that in iodine vapor at a certain temperature the molecules separate to atoms. But it may be questioned whether we have not seen solid elements in the atomic form without recognizing them as such. There are forms of iron, nickel, cobalt and lead which exhibit very remarkable properties, properties that have been hitherto very unsatisfactorily explained. Lead tartrate reduced by gentle ignition in a nearly closed tube and allowed to cool and then shaken out into the air forms astream of fire. The oxides of iron, nickel and cobalt reduced in closed tubes by hydrogen show similar properties. It is customary to explain this action by affirming that the metals are left in an extremely fine state of division. This explanation is not satisfactory. Sulphur, for example, is far more inflammable than any of the metals just mentioned and may be obtained in a state of exceedingly fine division, either by sublimation or by precipitation, but does not in consequence show any greater tendency to spontaneous inflammation. It seems more natural to suppose that these metals are reduced in the atomic form, and this view of the matter seems to be much strengthened by the following considerations. The experiments of Ramsey, and of Heycock and Neville, cited in a previous paper, lead to the conclusion that in the case of a dilute solution of one metal in another the dissolved metal exists in the atomic form. But still more the experi- ments of Tammann on amalgams indicate that in these alloys the dissolved metal is atomic, and it is stated that Joule by distilling off the mercury from an iron amalgam found that the iron was left in a pyrophoric condition. The amalgam of man- ganese, carefully distilled, gives a pyrophoric powder. Chro- A. Lindenkohl—Post-glacial Subsidence, ete. 489 mium amalgam, distilled in a current of hydrogen, gives a similar result if the temperature is not raised too high. The enormous affinity which these forms of metals exhibit for oxygen renders their study very difficult. It has not been before suggested that their activity is due to their being atomic, but this would seem to be a much more rational explanation than that of extreme division.* A broad distinction must of course be drawn between chemical and mechanical division: a substance may be atomic and yet appear in masses: may be in the finest mechanical division and yet be molecular or poly- merized. Silver being a metal with a very low affinity for oxygen could not be expected to show in the atomic state the same inflammability as more oxidable metals. In conclusion it may be said that there is much reason to suppose that elements may exist in the atomic form and that allotropie silver may present such a case. ‘This is of course far from being proved and is offered only as a “working hypothesis.” As such it may afford a useful aid in further investigations. : Philadelphia, April, 1891. Art. LIX.—Wotes on the sub-marine channel of the Hudson River and other evidences of Post-glacial Subsidence of the Middle Atlantic Coast Region; by A. LINDENKOHL. With Plate XVIII. THE American Journal of Science of 1885+ contained an article by the writer entitled “Geology of the Sea Bottom in the Approaches to New York Bay,” in which a description was given of a remarkable depression in the sea bottom off Sandy Hook and an attempt was also made to account for the origin of this depression and to trace its connection with the geology of the adjacent coast region. Professor Dana, who was the first to recognize the true shape of this depression and to direct attention to its existence by a map and reference in his “ Manual of Geology,” published in 1863, takes up the subject again in a recent number of this Journal »¢ treating of Long Island in the Quaternary with obser- vations on the sub-marine Hudson River channel, and carefully _ *M. G. Rousseau, in the new Encyclopédie Chimique, seems to entirely aban- don the old view of extreme division and considers these forms to be allotropic and comparable with the allotropic forms of phosphorus, ete. Vol. iii, page 56. + Vol xxix, pp. 475 et seq., also republished as Appendix No. 13, U.S. Coast and Geodetic Survey, Report of 1884. t Vol. xl, pp. 425-437. 490 rau Lindenkohl—Post- glaceal Subsidence reviews the well-ascertained facts connected with this depres- sion but on several points reaches quite different conclusions. It is the object of the following pages to review the sub- ject, and at the same time to introduce much information bearing upon it, which has accumulated since 1885, but has not appeared in print. Description of the Sub-marine Hudson River Channel.— The sub-marine depression, to which reference is made in the preceding paragraphs, has the characteristics of a river channel unmistakably impressed upon it and it is recognized as the sub- marine continuation of the Hudson River channel. It is first noticed at a depth of twenty fathoms, about twelve statute miles southeast from Sandy Hook. Its course is nearly south until abreast of and eleven miles from Long Branch, where it has attained a depth of thirty fathoms in fifteen fathoms of water. Thence it begins to turn to the southeast and attains its greatest depth of forty-five fathoms when fifty-three miles from Sandy Hook, the banks rising on both sides of the chan- nel to a height of fifteen fathoms within two or three miles. From here its depth begins to fall off until, at a distance of ninety-one miles from the Hook, the channel almost disappears with a depth of but forty-one fathoms in a surrounding bottom of thirty-nine fathoms depth. But, at a distance of ninety- seven miles, the channel begins to assume the character of a gorge or cafion, which character it maintains for a length of twenty-three miles, when it vanishes on the edge of the great continental plateau at a depth of about 200 fathoms. The average width of the river channel is about 14 miles, that of the gorge three miles with a greatest depth of 474 fathoms in about seventy fathoms of water. The bottom of the river channel and cafion as well as their slopes consist of a bluish slate-colored mud or clay with a fine sandy grit. This mud bottom extends for a considerable dis- tance on both sides, north and south of the cafion along the brink of the continental plateau. In trying to account for the existence of the upper part, or river portion, of the channel, it was assumed to be the result of fluvial erosion and to imply a subsidence of about 210 feet at a comparatively recent geological time, subsequent to the glacial period. The existence of the gorge was believed to imply a much greater subsidence than that of the upper chan- nel, a subsidence not far from 1200 feet (200 fathoms). No attempt was made to fix its geological date beyond the state- ment that its fiord-like shape favors the supposition that it existed as an elevated channel during a part at least of the glacial era, but that it must have sunken below the level of the of the Middle Atlantic Coast Region. 491 ocean at the time when its feeder was yet an actual river channel. The presence of clay on the bottom of the channels and on the slopes, and its absence elsewhere, was assumed to furnish proof for the assumption that this clay was not a mere super- ficial covering, but that it is formed im setu and gives indica- tions of strata in correlation with the Tertiary exposed towards the northeast at Gay Head, as well as with that of New Jersey, bearing west. The first one of these propositions, the one which accounts for the sunken river channel, is the most important and perhaps the most vulnerable one, and requires proof of the following corollaries: 1st. The shape and dimensions of the channel must accord with those which should be assigned to a hypothetical river of the size of the Hudson. 2d. Tidal and other currents now in existence cannot have produced the channel. 8d. A similar subsidence which must not necessarily be of the same amount, must be proved for the nearest rivers to the south, for the Delaware, Susquehanna (or Chesapeake) and Potomac. (The rivers to the north may be left untouched since Professor Dana has investigated the subject and recorded the results in his paper on Long Island Sound in the Quaternary, ete., mentioned above.) Ath. It must be shown that diluvial deposits do not lie con- -formably on the surface of these channels but are eroded b them, and all deposits found in the channels must be of alluvial character. 1. Size and shape of the Sub-marine Hudson Liver Channel.—The breadth of the channel is about one and a quarter miles, about the same as that of the river above the Narrows. From New York City to the Dunderberg the chan- nel is about three-quarters of a mile wide. These dimensions tally well with the conditions expected from an ordinary tidal stream, 1. e. increased capacity with nearer approach to sea. The main slope of the banks is 1°. This is less than we expect of living rivers, but we should take into consideration that, apart from currents, the corrasive action of sea water is constantly engaged upon the work of destruction. It is rather a matter of surprise to those who are familiar with the little power of resistance of clay banks in sub-aerial exposure when unprotected by gravel ledges or turf, that such banks should be preserved at all under the sea. No special reason can be assioned for the peculiarity that the river should first flow fifteen miles to the south before turning east unless we assume that it follows the fashion set by its neighboring rivers, the 492 A. Lindenkohl—Post-glacial Subsidence Delaware, Susquehanna, and Potomac, which all follow a southern and anticlinal course before they take up the straight road to sea. This uniformity in behavior of these four rivers points to a common cause, and a slight tilting of the Atlantic plain in a north and south direction suggests itself as the readiest way to account for the southern deflection of the rivers. Liffects of existing currents on the sub-marine channel.—The following table, giving the mean maximum strength of both sets of tidal currents in nautical miles, has been compiled from the latest observations for the purpose of testing the ability of those currents to create channels outside of the Sandy Hook bars. Table of Tidal Currents in the lower New York Bay. Mean Maximum Ebb. Mean Maximum Flood. Surface. Botton. surface. ottom. Narrows es): Si es05 52 eee 1°9 0°9 1°3 1:0 Fourteen Foot Channel. 1°9 0°9 1°6 1:0 Hast Channel__-... _-- 22 0-9 1°6 0°8 Swash Channel _____-- 2°1 0:9 1°8 | gy? Main Ship Channel__--- 2:3 0°8 1°8 1-2 Outer East Channel ___ 2°1 ie? 16 0-9 Gedney’s Channel--__- 2°3 0-9 1°8 1°0 South Channel_______- DD, 0°2 14 0:7 It will be seen from this table that the ebb current is the strongest surface current and maintains its velocity (19 to 2°3 knots) until the outer bars have been passed. . But its strength at the bottom of the channels is less than half that of the sur- face currents, and less than that of the flood current. The flood current is essentially a deep current and retains at the bottom, in spite of friction, nearly two-thirds of its surface velocity ; it is the flood current’s speciality to attend to the scouring business. But we cannot realize that a current which has but 1°2 nautical miles velocity at the places where it must be supposed to exert its greatest strength, can have the power to scoop out a channel forty-five feet deep and only a mile wide at a distance of fifty miles from the coast. At the same time the opinion is well-founded that the submarine channel is the principal passage way for the tide to and from New York Bay, and that this almost ceaseless flow tends to keep the chan- nel clear from encroachments, especially by that formidable bank, the Cholera Bank on the New York side of the channel. Often the tides may be reinforced by high seas produced by continuous easterly winds off New York; and although such high tides are known to be very destructive along the whole coast from Atlantic City to Fire Island, we have no reason to believe their effect to extend to greater depths than fifteen fathoms or to the depth of our channel. of the Middle Atlantic Coast Region. 493 Sunken River Channel in Chesapeake Bay.—As stated above, if the theory of a recent subsidence of the Hudson River is to be successfully maintained, a similar subsidence must be proved for the Delaware and for Chesapeake Bay. It must be confessed that for many years we have been searching for sunken channels for those bays without finding them; we were looking for them in a wrong direction, outside of the bays, instead of inside. We supposed Cape Henlopen and Cape Henry occupied relative positions to those channels analo- gous to that of Sandy Hook to the sunken Hudson River channel; we took the Coast-line as our line of departure in- stead of taking the /adl-line. This line which is easily identi- fied by the site of New York, Trenton, Philadelphia, Havre de Grace, Baltimore,* Washington, etc., separates two widely different geological regions, the region of crystalline and Trias- sic rocks to the north and west from the stratified clays and gravels to the south and east, and it must be assumed that any seismic disturbance would affect these two regions unequally and the coastal plain to a greater extent than the Piedmont region. Now, the s¢nkeng of the land to the extent of 100 feet, let us say fifty feet, would hardly affect the physiography of those parts of the country above the hypsometrical line of fifty feet, but all land below this level would be appropriated by the waters and reached by the tides; rivers with low shores would be converted into bays or estuaries, those situated in rising ground would have the lower parts of their valleys flooded. It now remains for us to examine Delaware and Chesapeake Bays for traces of deeper and narrower channels than those which can be accounted for by existing conditions. Passing Delaware bay, for reasons which will be explained farther on, and turning to Chesapeake Bay, we readily find, upon examining the soundings, a narrow and deep inner chan- nel which can be traced nearly through the entire length of the bay, from the mouth of Bush River to that of the Rappahan- nock, a distance of 120 miles. In an average width of the bay of ten miles, this channel commences with one mile’s breadth in its upper part, increasing to two miles near its southern limit. The descent of the bottom of the bay is very gradual from the shore until the depth of eight fathoms is passed, when the bottum abruptly plunges to the depth of about twenty fathoms (from fifteen to twenty-six fathoms). The bathymetrical line of forty-eight feet may then be taken as the limit of this inner deep channel. We subjoin four cross-sec- tions of the bay, taken about thirty-five miles apart. It will be seen that the areas of these sections are gradually increasing, Am. Jour. ScIl.—THIRD SERIES, VoL. XLI, No. 246.—JuNgE, 1891. 33 494 A. Lindenkohl—Post-glacial Subsidence going down the bay and that the last one, that off Wolftrap Point below the Rappahannock, is the largest, although the Cross Sections of the Susquehanna River Havre de Grace Lorene eee = 100 50 Too Feet; ae] Cross Sections of Chesapeake Bay From Gibson I to Kent I ieee From Plum Pt to Sharps I From Pt Lookin to Holland I At Wolftrap Point mn Y200 aoo Horizontal Scale Vericcat Scale 72400 deep cut in the bottom is missing. It does not matter what particular curve we accept as a type of cross-sections of tidal of the Middle Atlantic Coast Region. 495 streams, whether an ellipse or parabola, the cross-section at Wolftrap comes nearer to it than any of the preceding ones and no combination of circumstances, no shifting or turning of channel can satisfactorily explain, as a purely tidal phenomenon, the existence of the deep incisions at the bottom of the cross- sections. We are forced to conclude that these incisions are due to pre-existing conditions, that they show the former chan- nel of a river at a time when the whole region lay about forty- eight feet higher than at present, when Chesapeake Bay did not exist, but when the Susquehanna was at least 150 miles longer than at present (rather more than the submerged Hudson) and gathered upon its way to the sea the waters of the Patuxent, Potomac and Rappahannock. ‘The reason that we cannot trace the channel farther up the bay than Bush River and to the mouth of the Susquehanna is, no doubt, owing to the fact that the Susquehanna has filled up the upper part of its old channel, for which it has no further use, with its sediment ; and the borings to a depth of 140 feet at Fishing Battery, below Havre de Grace, through alluvium, which Mr. McGee reports,* quite favor such a supposition. As stated above, the channel disappears below the mouth of the Rappahannock with a depth of about fifty feet. I am not prepared now to answer the question, whether the bar and actual end of the old river is here or whether there is but a temporary interrup- tion of the channel by subsequent deposits from rivers empty- ing into the bay. The answer is not material to the present inquiry. The river channel appears to have hugged its eastern shore, which in several places appears to have risen into bluffs, from 15 to 25 feet high, while the western shore was low and marshy. The soundings in the bay are not the only indica- tions of a depression; they can be found everywhere along the shores of the bay, even by a mere inspection of the charts. It is entirely beyond the ability of the present sluggish streams to have eroded their channels to the great width which is so characteristic of the lower part of all streams entering the Chesapeake. The absence of deltas and bars at the mouths of the rivers, the almost total absence of drainage-area for a long strip of the western shore of the bay above the Rappahannock, all are suggestive of subsidence, in fact have been commented upon in this direction by Mr. McGee in his exhaustive study of the Geology of Chesapeake Bay.| On more than one ocea- sion he speaks of the drowned rivers of the bay. There is another way in which we may arrive at an estimate of the probable amount of subsidence. The profile given (p. 494) of the Susquehanna River at the crossing of the Baltimore and * Seventh Annual Report U.S. Geological Survey, p. 580. + Seventh Annual Report, U.S. Geological Survey, pp. 537-646. 496 A. Lindenkohl—Post-glacial Subsidence Ohio Railroad bridge above Havre de Grace, kindly furnished by Mr. Chas. F. Mayer, the President of the road, shows a con- siderable layer of mud intervening between the bottom of the river and the rocky granite floor. This layer has a thickness of fifty-nine feet in the west, and over seventy feet in the east channel. The river would most certainly not have cut a chan- nel into one of the hardest of rocks if there had not existed, at some time, a physical necessity for it, and the amount of filling or “ packing” of mud enables us to estimate the depth of the river at that time. Assuming the discharge to be stationary, we find that, supposing the mud to be removed, the river could be lowered forty-three feet and yet find sufficient space for the passage of its waters. The next profile (p. 494) is from the crossing of the Pennsylvania Railroad at Havre de Grace, about one mile to the southward of the B. & O. R. R. bridge. This profile was obtained from Mr. G. B. Roberts, President of the Penna. R. R. It shows the greatest depth of mud, 113 feet under the wharf at Perryville. It would appear then that the channel of the river ran very closely to its eastern shore which was then several hundred feet farther inland. The rock is stated by Mr. McGee to dip under the level of the river about one-quarter of a mile from the railroad bridge. A similar eal- culation for the level of the river with the rocky floor for its bed, instead of the muddy bottom, gives fifty feet below the present surface. These two estimates taken in connection with the result of borings at Fishing Battery mentioned above, would appear to prove that at the time when the level of the Chesa- peake was forty-eight or fifty feet lower with respect to the land than at present, Perryville and not Port Deposit, was at the head of tide and that strong currents swept down the Sus- quehanna past and on both sides of Watson Island, plowing into the clays of the coastal plain to a depth of ninety feet or more. The Potomac being a tributary of Chesapeake Bay, we should naturally expect indications of a sinking of the land at the head of tide, similar to those of the Susquehanna. An examination of several profiles of the river at the Free Bridge in Georgetown (the former Aqueduct Bridge, built about 1840) shows the excavation of the channel to be of quite different shape from that of the Susquehanna; it is flat at the bottom and only reaches to the depth of thirty-five feet from the surface. There was considerable “ packing” by mud before the bridge was built, about thirteen feet thickness on an average. The cross-section of the river was considerably curtailed by the construction of the bridge. The river has tried to regain its former status and nearly succeeded in this effort, by removing the greater part of the of the Middle Atlantic Coast Region. 497 mud at its bottom. Supposing all the mud and artificial obstructions to be removed, the river could stand a lowering of its level of but eleven feet. Judging from surface expo- sures, the rocks at the bottom of the river are frangible or disintegrated gneiss, which is certainly less obdurate than the granite of the Susquehanna gorge, hence we have to conclude that the dislocation here is scarcely one-fourth of that of the Chesapeake Valley. At the site of the proposed Memorial Bridge, 1000 feet east from Easby’s Wharf, rocky bottom is found at a depth of forty-four feet below the surface of the river; the stratum of mud here is about fifteen feet thick. At the Long Bridge, rock bottom has not been reached by boring or pile driving, and hard bottom in the Washington channel is seventy-one feet below the surface under a layer of sandy mud of sixty-nine feet thickness. The Georgetown channel has no mud at its bottom but runs over a hard bed of gravel and clay. A subsidence along the valley of the Potomac below Wash- ington, inferior to that of Chesapeake Bay, is attested by the bay-like expansion of all the affluents at their mouths. Subsidence in Delaware Bay.—I have not had the necessary time nor data at hand to make a similar inquiry about probable subsidence in Delaware Bay. In fact, we know Delaware River and Bay to have much stronger currents and to carry a greater amount of coarser sediment than Chesapeake Bay, and are prepared to find the traces of a former higher level less dis- tinetly preserved. Nevertheless, we can trace a deep channel from the ocean into the middle of the bay where it is appar- ently choked off by alluvial deposits which fill up the entire upper part of the bay, leaving just enough room for the river ehannel. This “blind channel” has a depth of from twenty- two to thirteen fathoms, and is separated from the main river channel by shallow banks. The ebb-channel in actual use by the river has but a depth of three and one-quarter fathoms in its shoalest reaches. A comparison of our recent surveys with those made about fifty years ago proves that the high-water line, on the New Jersey side at least, has receded about one-eighth of a mile in the lower bay; but it would be rash to make subsi- dence responsible for this result. A comparison of the hydro- graphic surveys made about the same respective dates shows that there has been a great deal of shoaling going on in the interval, and it is not impossible that this shoaling has produced a disarrangement of the tidal elements, a retardment accom- panied by an increase in amplitude which would show its effects on the high-water line. Time of subsidence.—The evidence of a subsidence of the coast of New Jersey during the past century and yet in progress, collected by the late Professor Cook, must be consid- 498 A. Lindenkohl—Post-glacial Subsidence, ete. ered as the main support of the theory which accounts for the existence of the submarine channel of the Hudson by sub- mergence. In order to approximate the time of commence- ment of subsidence we have to take the evidence afforded by the latest Quaternary deposits. According to Mr. McGee* the clay terraces on which the city of Washington is built and which are supposed to be cotemporary with the first glacial invasion, indicate a submergence of about 150 feet during the period of their deposition. Hence it appears that the Lower Potomac and Chesapeake Bay with their depressed channels are of more recent origin. The borings at Fishing Battery cited above, which went to a depth of 146 feet and brought nothing to light older than alluvium, teach us that the deep channel of the Chesapeake must be of more recent date than any of the Tertiary and Quaternary deposits about the head of the bay. The submarine border of the coast.—Returning to the subject of submarine channels, it has to be stated that diligent search has thus far failed to discover indications of such for either Chesapeake Bay or Delaware Bay, with the exception of a deep cul-de-sac of 396 fathoms inside of the bathymetric line of 100 fathoms, occupying nearly the same relative posi- tion to Delaware Bay as the cafion described above does to the Hudson. | 3 In studying the geological changes in the sea bottom off the Middle Atlantic States, a remarkable fact should not be lost sight of. The sea bottom intervening between the submarine Hudson river channel and the coast of Long Island is charac- terized by its great regularity and. smoothness, which can best be explained by assuming a gradual subsidence or an adjust- ment by superficial deposits. The bottom between the channel and the New Jersey coast, on the contrary, is distinguished for its ruggedness; great irregularities in the soundings give indications of shallow ridges and of cross channels, which go to prove that there was a periodical retrogression of the coast line, and that the sea keeps the conquered territory in very much the same condition in which it was found. Greensand at the sea bottom.—The specimens of bottom collected during the recent survey of the approaches to New York, of which there are several hundreds at hand, show con- siderable quantities of black grains, described black specks on the charts, mixed up with the sand and mud of the entire region from Cape May to beyond Montauk Point; it is only in the mud of the gorge and of the deeper part of the continental slope that they are either scarce or missing. They are of spherical shape, of jet black luster, of brown color when fractured, and vary in size, with the fineness of the sand or mud, from the * This Journal, vol. xxxv, May, 1888. I. C. Russell— Glacial Records in the Newark System. 499 size of a pin-head to microscopical dimensions. They were evidently not composed of hornblende, and I hesitated to pro. nounce them greensand, which material Mr. Pourtales, in 1869, reported to exist in the sands off Long Branch and Rockaway Beach.* Mr. McGee was kind enough to have an examination made in the laboratory of the U. 8S. Geological Survey and informs me “that the black grains are, as Count Pourtalés supposed, glauconite. The mineral seems to have undergone a curious alteration and the grains were polished through attri- tion and partly through chemic and mechanical alteration akin to that of nodulation, but the density, optical properties, hard- ness, ete., of the broken grains are identical with the like prop- erties of New Jersey greensand from the Cretaceous and Eocene.” It was an open question with Mr. Pourtales whether these grains were washed out to sea from the marl beds of New Jersey or belonged to beds cropping out at the sea bottom. In view of the great extent of ground over which these grains are spread, and the great distance from the New Jersey coast, close to Montauk Point for instance, the first supposition can no longer be maintained; they must be treated either as be- longing to marl beds laid bare by the sea or as the remnants of such which have been destroyed by the sea.+ Whether these beds were Cretaceous or Eocene strata is a question which probably can only be decided upon paleontological grounds, but the preponderant strength of the Cretaceous on the mainland certainly speaks in favor of the latter having sup- plied the greatest amount of greensand grains to the ocean’s bottom. March 26, 1891. Art. LX.—Are there Glacial Records in the Newark Sys- tem? by IsRAEL C. RUSSELL. SEVERAL expressions of opinion have been published by geologists in this country, respecting the existence of glaciers along the Atlantic border during the deposition of the rocks of the Newark system. It has been recently stated by Prof. J. D. Dana,t that this period ‘‘ended in a semi-glacial era, as is * Appendix, No. 11, U. 8. Coast Survey, Report of 1869, also Petermann’s Geogr. Mittheilungen, vol. xvi, pp. 393-398. + Quartz sand.and pebbles, and greensand (perhaps hornblende) seem to be the only minerals which preserve their integrity in moderate depths at the bottom of the ocean; feldspar and mica are rarely found, and the so-called ‘‘ mud” consists very often of the finest sand with some mica flakes, and with a just sufficient admixture of clay to produce cohesion. t This Journal, III, xl, 1890, p. 436. 500 L. C. Russell—Glacial Records in the Newark System. admitted by all who have studied the beds.” As there is pos- sibly not the unanimity of opinion among those who have stud- ied the Newark system, that is suggested in the line quoted ; it may be well to glance at the evidence on which those who consider that the period referred to contains glacial deposits or ended in a semi-glacial era, base their conclusions. In describing certain coarse deposits on the eastern border of the Deep River area of Newark rocks in North Carolina, W. © Kerr* suggested that they indicate a sub-Newark elaciation but these beds are considered as post-Newark by W. M. Fon- taine.t A similar remark was made by N.S. Shaler and W. M. Davis,t in reference to the origin of the coarse conglomer- ate of the Newark system in the Connecticut valley. It has also been stated by J. D. Dana§ that the Connecticut valley had its violent floods during the Newark period, which may have been enlarged by the waters and ice of a semi-glacial era. But the most extended discussion of the possible glacial origin of certain coarse deposits in the Newark system has been made by W. M. Fontaine.t The arguments he advances are based on the following considerations : first. The presence of coarse conglomerate and _ breccias. Second. Absence of fossil mollusks, radiates, ete. Third. Un- explained phenomena in the drainage and relief of the Appala- chians, which are supposed to have been initiated by glaciers. Fourth. Extinction of the fauna and great change in the flora of the Atlantic border in the interval between the Newark and Cretaceous periods. The evidence of glaciation according to Danal “consists in thick deposits of stones and bowlders in which occur masses two to four feet in diameter, and therefore such as only ice could have handled and transported. They are situated along the west side of the area in Virginia, Maryland and New Jersey (where the dip of the Jura-Trias [Newark] beds is westward) and on the eastern in Connecticut and Massachusetts (where the dip is eastward).4] Fontaine has found in Virginia and Maryland that they are the later beds of the formation.” Ex- posures of Newark rocks north of Amherst, Mass., containing bowlders three to four feet in diameter are referred to, and Edward Hitcheock’s conclusion that they are “the upper beds” of the series, cited. Coarse deposits near East Haven, Conn., are also mentioned. * Rep. Geol. North Carolina, vol. 1, 1875, p. 146. + This Journal, III, xvii, 1879, p. 34. ¢ Illustrations of the Karth’s surface, Glaciers. Boston, 1881, pp. 95, 96. § This Journal, III, xvii, 1879, p. 330. || This Journal, III, xl, 1890, p. 436. *] Note in this Journal, III, xli, 1891. I. CO. Russell— Glacial Records in the Newark System. 501 Before examining the evidence, let us endeaver to determine what facts should be looked for, in case glaciers did invade the area in which Newark rocks were being deposited. Preservation of Glacial Records. All records of glaciation not buried beneath subsequent deposits, would certainly be destroyed by subaérial decay and erosion, during such a lapse of time as has intervened between the Newark period and the present day. Exception to this conclusion may, perhaps, be found in the changes which gla- ciers make in the drainage and topography of a region, but this matter is as yet little understood. Among the direct evi- dences of glaciation which might be preserved for indefinite ages, under suitable conditions, the following may be enume- rated : : “irst. Smoothed and striated rock surfaces, if buried beneath fine sediments, might be preserved in their original condition ; or casts of them might be taken, in the same manner that casts of footprints, showing the most delicate markings, have been preserved in great abundance in the Newark rocks themselves. Second. Bowlders, smoothed, faceted and striated by glaciers (similar markings are also produced by river ice), might retain their records for indefinite periods, especially if they were im- bedded in fine sediments or cemented by calcareous or other infiltrations.* Third. When glaciers enter an estuary or a lake, moraines are deposited in unassorted or but impertectly arranged, heaps about their extremities. The distance from the shore to which these deposits may be carried depends on the size of the glaciers and on the depth of the water they enter. A shallow estuary or lake could offer but feeble resistance to the advance of glaciers and might have moraines deposited widely over its bottom. On the other hand, glaciers entering a basin in which the water is as deep as the ice streams are thick, would have their advance checked abruptly and the moraines deposited would be con- fined to the borders of the basin ; but scattered bowlders might be carried to great distances on floating ice. Should glaciers plow their way into shallow basins in which fine sediments were being deposited, it is evident that the beds beneath them might be greatly disturbed, while contortions would appear in adjacent strata owing to the unequal distribution of the load imposed on them. * Since writing these pages, a paper has appeared by Dr. Hans Reusch, on ‘Glacial strize and bowlder-clay in Norwegian Lapponie from a period much older than the last ice-age.” Norges geol. undersdgelse aarbog for 1891, in which descriptions are given of striated rock surfaces protected by morainal material containing striated and faceted bowlders. These records are thought to be of Cambro-Silurian age. 502 L. C. Lussell— Glacial Records in the Newark System. Fourth. The effect of a glacial period on ‘animal and plant life has received much attention, but what records of the pres- ence of glaciers at any special time might be expected in con- temporaneous fossils, is still indefinite. A glacial period is usnally considered as a cold period (the presence of local gla- clers in mountainous regions, however, does not imply an Arctic climate). If a cold period followed a warm period, it is to be expected that migrations of fauna and flora would fol- low. Alternations of warm and cold periods would probably be accompanied by the extinction of many types. That changes of this character did take place during the Pleistocene glacial epoch, is apparently well established. On the other hand, we know that luxuriant floras exist on the margins and even on the surface, of living glaciers of vast extent, which are not essentially different from plants of the same species growing at a distance from all perennial ice. In the present state of knowledge, it does not seem possible for paleobotanists to designate any group or assemblage of fossil plants which might “not have flourished in proximity to glaciers. While glaciers may be cunranael by a mild atmosphere, congenial to plant life, the waters into which they discharge elther directly or after melting, are cold and could not be inhabited by animals characteristic of temperate or tropical climates. It is to be expected, therefore, that sediments laid down in water into which glaciers are discharging could only contain the records of faunas, exclusive of land animals, characteristic of cold climates. Weight of the Evidence. Having in mind what records might reasonably be expected to occur in the rocks of the Newark system, providing glaciers had assisted in their deposition, let us see what the facts are: first. No smoothed or striated rock surfaces either in the Newark system itself or on the floor on which it rests, have ever been found. Second. No glaciated bowlders have been observed in the system. Third. No scattered béwlders or large rock fragments indi- cating iceberg drift, have been found in the off-shore deposits. Fourth. No Newark fossils indicating a cold climate, even in a remote way, have been discovered. The paucity of molluscan life has been advanced as indicat- ing Arctic conditions. It is well known, however, that mol- lusks and many other forms of life, inhabit the seas of northern regions close to where glaciers discharge. Shells occur also in I. C. Russelu— Glacial Records in the Newark System. 503° Pleistocene glacial clays. The evidence that glaciers are not necessarily accompanied by an extermination of mollusks in adjacent waters, is abundant. Besides, the hypothesis that mollusks are absent from the Newark sediments on account of glacial conditions, does not stand alone; other explanations of the same phenomena with many facts to support them have been advanced. I have previously suggested that the great numbers of rep- tiles, some of them of gigantic'size, the bones and foot prints of which occur in the Newark rocks, could not have lived in an estuary or lake into which glaciers were discharging and on which icebergs floated. Cold-blooded animals at the present time among which we must look for the nearest living allies of the “foot-print animals,’ are confined to warm regions; and there is no reason to suppose that this law of nature was reversed during the Newark period. The swarms of reptiles, both great and small, that lived at that time must have required an abundant food supply; this implies that the shores they haunted were more like those of Florida than those of Green- land at the present time. The fossil plants of the Newark are Araucarians, ferns, equiseta and cycads. If these have any bearing on the ques- tion of climate they indicate sub-tropical and not Arctic condi- tions ; although there is no reason why they might not have grown in proximity to glaciers. | In regard to the marked modifications in the flora and the extermination of the fauna of the Newark period, before the deposition of the next succeeding formation, referred to by Fontaine, we know that such changes have occurred at the close of each important division of geological history and may be accounted for in most cases by the imperfections in the records. breaks in the life records invariably accompany breaks in stratigraphy. The assumption that these changes at the close of the Newark period were due to glaciation, is mak- ing an exception to a general rule, without facts to support it. The Coarse Deposits. It has been stated by Hitchcock and Fontaine, that the coarse deposits of the Newark system belong at the top. These statements lead Dana, as already cited, to the conclusion that the Newark period ended in a semi-glacial era. If the coarse deposit were confined to the top of the series, which as I shall show below, they are not, it would scarcely follow that they marked the close of the period, for the reason that deep erosion has unquestionably taken place. But the coarse deposits are not confined to the top of the series. Wherever the base of the system is exposed it is almost (504 LI. CO. Russell—Glacial Records in the Newark System. always found to be a coarse conglomerate or breccia. This deposit has been brought to the surface in several instances by faults and its character is well known. Coarse conglomerates occur especially on the east border of the Connecticut Valley area and on the west border of the New York-Virginia area and the detached areas in Virginia and North Carolina which fall in line with it. The beds are not continuous, but occur as local deposits. Where the coarse material is thickest, it grades into fine material both along the strike, that is along the shores against which it was deposited, and in a direction at right angles to the shore. Toward the center of the area of deposition, the coarse beds become fine and overlap or interdigitate, with fine off-shore sediments. As the upheaval of the system has not been uniform, erosion has cut far deeper in certain localities than at others. Thus, in northern New Jersey the Newark rocks are known to be not less than three or four thousand feet thick, while in the prolongation of the same area in Maryland, the thickness is certainly much less. The present base-level of erosion has cut deeper into the system at the south than at the north; yet all along the ancient shore, joining the two ex- tremes, coarse deposits occur from time to time. The evidence points definitely to the conclusion that coarse deposits oecur at all horizons from the bottom of the system up to the highest beds that now remain. If these beds are glacial deposits, then glaciers must have existed throughout the deposition of the system. The coarse deposits along portions of the borders of the vari- ous Newark areas are always of local origin. They are not heterogeneous accumulations gathered from a broad area, as might be expected if they are of glacial origin, but have been derived from terranes in the immediate vicinity of where they now occur. The material forming the large bowl- ders in particular, may invariably be found 77 situ, near at hand. No contortion of the fine sediments adjacent to or interstrat- ified with the coarse deposits have been observed, such as would result from the extension of glaciers into the basins in which the fine sediments had been accumulated, or from the superposition or moraines upon them. On the contrary, the phenomena noted at many localities are fully explained on the assumption that the strata both coarse and fine, were deposited contemporaneously as water-laid beds. The fine deposits intimately associated and even interstrati- fied with the coarse deposits, are frequently ripple-marked, sun-cracked, and contain rain-drop impressions and the foot- prints of animals, at many horizons; thus showing conclusive- ly, that the water bodies in which the strata were spread out were shallow. There is, therefore, no reason why glaciers F.. H. Bigelow—The Theory of the Solar Corona. 505 entering the basin should have halted at the immediate shore, and deposited their loads. Besides, the coarse deposits are not of the heterogeneous character typical of morainal accumula- tions, but are stratified and cross-bedded. It has been stated by those who claim that the deposits in question are of glacial origin, that they contain bowlders three to four feet in diame- ter, and therefore such as only ice could have handled and transported. My own observations have shown that bowlders either rounded or sub-angular, of the size indicated are not rare. Huge angular masses of rock like those to be seen on nearly every Alpine glacier, however, never occur. Those of my readers who have followed the Appalachian rivers south of the southern margin of the drift, will remember many instances where streams are encumbered with bowlders of even larger size than those mentioned above. These are being swept along by every flood, and did the streams empty into lakes, would be deposited in shore conglomerates. It may be remarked also, that river ice might have assisted in the movement of the Newark bowlders, without supposing the existence of glaciers. After reviewing the voluminous literature relating to the Newark system and personally examining nearly every area occupied by it, I fail to find any evidence to support the hy- pothesis that glaciers assisted in its deposition. That there may have been glaciers on the Appalachians previous to or during the Newark period, is within the bounds of possibility, but as yet there is no evidence in this connection on which to base an opinion; we can only say that if they were present during the period under discussion, they did not reach the estuaries in which sediments were being deposited. Washington, D. C., Feb. 15, 1891. Art. LXI—A reply to Professor Nipher on “ The Theory of the Solar Corona”, by F. H. BraEtow. In the Report of the Washington University Eclipse Party, on the Total Eclipse of the Sun, January 1, 1889, Professor Francis E. Nipher makes a criticism of my paper on the Solar Corona published by the Smithsonian Institution, 1889. The theory which I have proposed is of itself sufficiently technical in a mathematical sense, not to be burdened with an inaccurate or irrelevant criticism, and I therefore wish to make the three following observations on Professor Nipher’s Report. _ 1. The mathematical non sequitur of the work on pages 22, 23 is so obvious as to need no special comment. Jam informed that the equation for the line of foree which should follow “= 506 #. H. Bigelow—The Theory of the Solar Corona. from the equation of the force at any point, (3 cos*w+1)?, 1s not what he intended to have appear. Instead : + 2apa’ : ; : of reading, N = (3 Cos wo+1) (1—cos w) + o7R’sin’a, it | 1 2a pa* 22.9 Oe rm ‘ : should read, N =—— sin w+zeRo’sin’w. The equation in aie : sin’@ its corrected form gives two terms, the first, Angus, which uv is identical with that employed by me in my paper, and the second, zpR’sin’w which Mr. Nipher ascribes to the action of a uniform field of force surrounding the Sun. 3 2. At this place the ways part, and the irrelevant criticism begins. The equation in N with one term represents a certain condition of things; the equation in N with two terms is a different case and belongs to another state of things. If any- one is curious to see the two cases fully represented graphically, let him turn to Maxwell’s Electricity and Magnetism, vol. i, fig. 5, Art. 143, for the first. and to vol. i, fig. 15, Art. 484, for the second. Professor Nipher is at liberty to ascribe the second case, as his own, to the conditions about the sun, but there is no need to dedicate it to my theory, because it was not employed by me. There is no evidence that the sun is placed within a field of uniform force, produced outside of itself, nor is it necessary to resort to such a supposition in order to account for the forms of the coronal streamers, as seen from the earth. When we come to consider the earth the case is different from that of the sun, simce we have some reasons for thinking that the earth les in a uniform field, generated by the action of the sun upon the earth. As I pointed out in the same paper it may be necessary to treat the field surrounding the earth by the full equation, written by Professor Nipher. I have pub- lished a theory for doing so, employing the configuration of the auroral streamers, if suitable observations can be obtained ; [this Journal, February, 1891.] 3. It must be perfectly understood by students of this sub- ject that most of the mathematical devices for discussing the field of force surrounding a polarized sphere, are physical fictions. There are many such devices, as for instance: (1) two equal masses of electricity with opposite signs placed infinitely near together at the center of the sphere, (2) the cosine distri- bution from a maximum superficial density at the axis, (3) the polarized sphere or the layers of gliding, (4) an indefinitely small magnet at the center of the sphere, and others. From such suppositions the mathematical treatment builds up the W. 7. Brigham—Recent Eruption of Kilauea. 507 observed lines of force surrounding the sphere. That there might be no doubt about my own position on the subject, I arrived at the formula for the lines of force by the geometrical and also by the harmonic analysis, never imagining that a eritic would convert this common mathematical process into a physical reality of the sun’s constitution. We are now interested to discover an analytical expression for the curvature of the coronal streamers; their physical nature is another ques- tion, one which is at present beyond our knowledge; it shares the perplexity attending any discussion of electrical or mag- netic action. This then is the second irrelevant criticism. [ did net suppose that the cosine distribution of electricity was actually plastered over the surface of the sun, and there was no need to allude to this point. Professor Nipher quotes me as saying, “on the supposition that we see a phenomenon similar to that of free electricity,’ (p. 21.) If the presence of the word “similar” was not sufficiently explicit as to my meaning, he should have quoted from page 19 of my paper as follows: ‘“ We have avoided speaking of the apparent coronal structure as a phenomenon of electricity, in deference to the doubt that free electricity can exist at such high temperatures on the sun’s surface, but have shown that some force is present acting upon the corona according to the laws of electric poten- tial.’ No one can at present explain the physical constitution of the matter that produces the coronal streamers, but I have in my work endeavored to show that they coincide in direction with stream lines produced by matter obeying the Law of the Newtonian Potential Function in the case of Repulsion. Such evidence as has been acquired to exhibit this identity of form between the coronal lines and the theoretical lines is now being published. [Proc A.S. P., No. 16 or No. 17, and this Journal, July, 1891. ] Washington, April 29, 1891. Art. LXII.—On the recent Eruption of Kilauea; by W. T. BRIGHAM.* I PRESENT herewith my report on the changes that have taken place in the crater of Kilauea during the past month. The last week of February, I found the crater in a state of intense but not extensive activity. During the seven months that had elapsed since my last visit, the depressed area of 1885 had been filled to a height of nearly 150 feet, and there were * Report to Prof. Wm. D. Alexander, Surveyor General, dated Honolulu, H. L., April 8th, 1891. 508 W. T. Brigham—fecent Eruption of Kilauea. indications that the entire floor of the crater, which has long been domed, had been elevated to some undetermined extent. One indication of this was seen in the great crack which extends across the trail near the eastern edge of the crater. This crack had closed nine inches. The peaks that have long been an interesting feature of the fire area, as well as a land mark for the whole crater, had risen with the tide, and now towered at least 200 feet above the pools of liquid lava at their feet. Seen from the Volcano House, one-third of their total height was above the outer western wall. Their structure was loose, and so much smoke or sulphurous fumes escaped from almost their entire surface that it was not safe to attempt the ascent. On all sides they were surrounded by cones, generally hot and ejecting lava spatters. ‘These cones were, in at least two cases, high up on the side of the main peaks, and exactly resembled the ‘‘ Horni- tos” of Humboldt. Several of the cones could be approached closely enough to throw blocks of lava into the oven door. One large cone of a group of three had become extinct, and one- half had fallen in fragments, showing the smooth inner walls, and the exceedingly superficial nature of its action. The wind was southerly, and it was therefore easy to go to the south and west of the fire area. Southeast of this was an extensive lava flow, covering some six acres, and proceeding from the base of a cone. To the southward of this a previous flow had formed a high ridge of “a-a.” West of the peaks was the most active portion, while in July the active lake was on the southeast side. The northern pool was the largest, of an irregular shape, having a promon- tory extending a third of its diameter from the middle of the western side. Its diameter, north and south, may have been 250 feet, and the banks were of unequal height but averaged fifteen feet above the lava surface. The next pool was the smallest, but the most active, and was 500 feet south of the first. Its diameter was less than one hundred feet, but the banks were overhanging. The third pool was near the last. and intermediate in size. All these pools were seemingly on a level, and were in my opinion connected ; the crust intervening being pot more than fifteen inches thick, and quite hot, although all the neighbor- hood was covered with a thick coating of ‘ Pele’s Hair,” a good non-conductor. The usual intermittent action was no longer there: the surface had no time to cool, and no crust was allowed to cover the surface. [rom all the pools spatters of considerable volume were thrown on to the surrounding banks, and the direction of these jets was very peculiar. The molten lava was thrown obliquely, and the bright matter de- W. T. Brigham—Lecent Eruption of Kilauea. 509 scribed figures not unlike an interrogation point ; the plane of these fioures was quaquaversal. There was remarkably lttle sulphurous vapor, and the absence of steam would have puzzled those geologists who impute to its agency the volcanic action. Outside of the crater, however, steam was isstiing im several places; among these, the top of the wall near the Kau trail; the eastern wall between the two lateral craters; and the depressed wall be- tween the main crater and Kilanea-iki. As we left the pools in the evening, it was noticed that a cone some fifty yards west of the southern lake was sputter-. ing in a very excited manner, and at 2 o’clock the next morn- ing we saw it from the house spouting lava to an estimated height of twenty-five feet, while detached spatters were thrown twice that height. At 8 o’clock, when we left the crater, the fire fountain was still bright in the full morning light. It seemed to flow as freely as an uncapped artesian well. This was nearly the condition of the crater a week later, when on March 6th, 1891, at 9.380 P. Mw. a shght earthquake was felt at the Volcano House, and the cones settled slightly. The next. morning the peaks were out of sight. At Punaluu stronger earthquakes were felt, and at the Half Way House, the ground was in a continual tremor for some time; 3800 shocks were counted in one night, but no accurate record was kept. On the 2d of April, at your request, I visited the crater again and found the following condition of things. From the house the absence of two landmarks,—the peaks and the column of smoke, was at once noticed, and as night fell the accustomed look toward Halemaumau met not the slightest glimmer of light; all was as cold and dead as the orand old dome of Mauna Loa ten thousand feet above it. The next morning the yawning pit was clear cut as seen from the house, and only a pale bluish smoke arose from its lips. Beyond, to the southward, was a white smoke that rose and fell, but was not of considerable extent. On descending into the crater the crack was found unchanged. Many smaller cracks intersected the trail, especially towards the middle of the crater, but the condition of the stone monuments on the Rock called the “ Half Way House” showed conclusively that there had been very little disturbance in the crater itself: not one of the stone piles had been upset. The lava flow noticed on the previous visit was still warm, and on the borders of the depression was red hot. The entire fire area was gone. Peaks, cones and pools had vanished, and in their place was a pit AM. Jour. Sci1.—THIRD SERIES, Vou. XLI, No. 246.—Junz, 1891. 34 510 W. LT. Brigham—Recent Eruption of Kilauea. crater of elliptical outline, 2500 by 3000 feet, the major axis being nearly ‘east and west. The walls were perpendicular and quite impassable. The estimated depth was 500 feet. There were many concentric and radial cracks making it dan- gerous In many places to approach the edge. Almost all the smoke proceeded from the hot upper crust of the border, none came from the bottom ; and while every portion of the pit was clearly seen, the heated air constantly rising from the border made photographing a partial failure. Portions of the cracked lips had sunk, leaving steps toward the pit. There was a com- plete absence of any black in the walls or bottom; all shades of brown, red and yellow, but generally light: not in the least dismal or fresh looking, except for size, it looked quite like Mokuaweoweo, and might have been as old. The walls were in remarkably even layers; no cavities, dikes or great irregu- larities were to be seen. It was a wall of masonry whose cement time had crumbled, and it would hardly have seemed out of place had some vine trailed its festoons down the courses. The bottom was a confused mass of lava blocks of the same color as the walls, and was deeper at the west side. The impression was that the top of the peaks was there. Owing to the bad arrangements of the Inter-Island 8. N. Co. we were hurried away at daybreak the second morning, and so had no opportunity to photograph from the western wall, nor to take the desired measurements. The location is however settled with sufficient accuracy as the whole area covered by the last break-down and the pool to the eastward as well. No word could be heard of any surface flow “ makaz” (sea- ward) of the crater, but from the steamer as we left Punaluu Saturday afternoon, a dense smoke was seen midway between Kilauea and the sea, which might have been a forest fire, or an outbreak. It is useless to speculate as to the return of the fires: the present condition of the pit precludes any approach to them were the bottom dotted with fire-pools. In 1886, the wall was sloping on one side at least, affording access to the bottom. Any earthquakes may however topple down enough of the present wall to make a descent possible and the fires may be visible in a week or not for months. In its present condition Kilauea is most interesting to geologists, as in the walls of its included pit is an epitome of the formation of the mountain itself, a clean-cut section of 500 feet. C. H. Snow—Turquois in New Mexico. 511 Art. LXIIL—TZurquois in Southwestern New Mexico; by CHARLES H. SNow. SoME years ago excavations of ancient origin, the object of which was unknown until recently, were noticed in the Burro Mountains, southwest of Silver City, in Grant County, New Mexico. During the past year, Mr. W. J. Foley, then of Silver City, received a letter from a firm of Indian traders, in which it was stated that the Navajos claimed that turquois existed near Silver City, mines being described as having been worked at some remote period in an extensive, though primi- tive, manner. A search, thereupon instituted by Mr. Foley, resulted in an apparent connection between this story and the ruins above noted. The locality has since been visited by the writer, who found the excavations situated upon several adjoining hill slopes. Although extending over considerable territory, they occur in isolated groups, and do not convey the impression of any very extended single effort. The size and character of the waste piles seem rather to indicate shallow works, although at one point a shaft or deep pit existed, and at another, close by an abruptly rising hill, either a shaft or a tunnel into the ‘hill. All adits have long since been obliterated; and the piles of debris are more or less concealed by vegetation. The waste rock is in large pieces, and was evidently mined by the most primitive methods. It consists of gray quartz with white cleavable feldspar unlike that at the locality next described. Turquois was found in occasional small pieces attached to or seaming the rock, the color being the same pea-green shown by the ‘‘ Los Cerillos stone.” No metallic matter was noticed. Continued search by Mr. Foley resulted in the location of another claim, about a mile distant from the one mentioned above, and near the “Chief of the Burros” copper mine, not now worked. There exists here a test pit, sunk some years ago as a copper exploration, the veins of turquois having been, strange to say, mistaken for veins of ores of that metal. The pit has a dimension each way of about three feet. It is upon the summit of a dike of a buff-colored rock traceable for some at each side of the pit. The dike matter, as seen in the pit and at one or more places upon the surface, contains a perfect network of turquois. The layers are from a line to an eighth of an inch in thickness, frequently starting in a thick layer, and then forking into several finer ones, which again subdivide. Where the layers are thick, a tendency of the rock to cleave away at the line of contact was sometimes, but not always, 512 Scientific Intelligence. noticed. The layers occasionally had an abrupt lateral ter- mination, like the edge of a volume of thick fluid poured upon a flat surface. | Besides the layer formation, turquois was also noticed in small dots and in isolated patches, which occasionally differed from the vein matter in being of a more bluish shade. The prevailing color, however, was the green, common to the American turquois, and typified at Los Cerillos. Turquois is known to occur at two other points in Grant. County, New Mexico, both of them in the Burro Mountain district. From one of these the writer has specimens, con- sisting of sheets of very thin turquois having several square inches of surface area and from which gangue matter similar to that at the locality near the copper mine has been entirely removed by decomposition. — s SCIENTIFLE INTELLIGENCE: I. CHEMISTRY AND PHYSICS. 1. On the Compressibility of Hydrogen, Oxygen and Nitrogen. —AmacaT has subjected hydrogen, oxygen, nitrogen and air to pressures varying from one hundred to one thousand atmo- spheres, at temperatures of 0°, 100° and 200°. He finds that for hydrogen the values of dvu/dt are practically independent of the temperature, the coefficient of expansion diminishing regularly as the pressure increases; while for nitrogen, oxygen and air, this coefficient passes through a maximum corresponding to the pressure at which the product pu has its minimum value. The values of dp/dt for hydrogen are also practically independent of the temperature, and nitrogen and air resemble hydrogen in this respect. Indeed the properties of hydrogen seem to be limiting values toward which those of all other gases tend; these limiting values of dv/dt and dp/dt being independent of the temperature, the former diminishing and the latter increasing as the pressure rises, the change being regular in both cases. At pressures up to 3000 atmospheres and at all temperatures, the isothermal lines have been shown by later experiments not to be exactly straight lines but to have a slight concavity toward the axis of abscissas. —(. &., exi,-871 ; J) Chem. Soc:; |x, 378, April, 1891) sca 2. On Osmotic Pressure.—In 1888, an analogy was pointed out by van’t Hoff between the physical condition of a substance in dilute solutions and in the gaseous condition, osmotic pressure in the former case being the analogue of vapor-pressure in the latter. Botrzmann has now investigated osmotic pressure mathe- matically from the standpoint of the kinetic theory of gases. He supposes a cylinder, having a semi-permeable septum in the middle dividing it into two equal parts, and having its ends Chemistry and Physics. 513 closed by pistons. One of the compartments thus formed is filled with a dilute solution, the solvent of which alone can pass through the septum. The other compartment is filled with the solvent only. Osmose takes place, the solvent entering the solution through the septum and increasing the pressure exerted by that solution; the flow continuing until the osmotic pressure is bal- anced by the pressure within the vessel. By varying the pres- sures upon the pistons, equilibrium may be produced, and the osmotic pressure measured. The author proceeds to treat this osmotic system, with reference to the forces in operation in its various parts, in the same manner in which the problem would be discussed with reference to the kinetic theory of gases. And he finds in this way, that the resultant of all the forces in the two compartments which produce pressure on the septum, 7. e., the osmotic pressure, is equal to the gaseous pressure which the dis- solved substance would exert were it distributed as a gas throughout the volume occupied by the solution, assuming that the mean kinetic energy of a dissolved molecule is equal to that of a gaseous molecule at the same temperature.— Zedtschr. physik. Chem., vi, 474; J. Chem. Soc., 1x, 389, April, 1891. G. F. B. 3. On the Production of Electrification in the Preparation of solid Carbon dioxide.—In order to obtain rapidly and conven- iently a considerable quantity of solid carbon dioxide, Hauvss- KNECHT fastened over the jet of a wrought iron cylinder contain- ing the liquid dioxide, such as is found in commerce, a bag of coarse linen cloth. By inclining the cylinder, the liquid issues under a pressure of 60-80 atmospheres, and in expanding into the gaseous state, absorbs so much heat as to solidify a portion of the escaping liquid, this solid collecting in the bag in the form of a compact snow. If the bag be made of strong canvas and have a capacity of from one to two liters, and if the experiments be conducted in the dark, it will be observed that the bag is filled with a greenish-violet light and that electric sparks from 10 to 20 long issue from its surface. If the hand be placed in these sparks the same peculiar: prickling effect is noticed as when it is brought near the collector of an electric machine. This appear- ance of electrification is especially noticeable where imperfections occur in the compression pump or in the valves or manometers, so that the carbon dioxide issues under great pressure. The cause of this development of electrification is no doubt similar to or identical with that which operates in the hydro-electric machine of Armstrong. The liquid issuing with great force is converted into gas at once when it reaches the air. But under so great a pressure and at so low a temperature, the gas thus forced through the openings in the bag is accompanied by fine particles of the liquid, and probably of the solid also; the friction of these solid and liquid particles developing the electri- fication. For the success of this experiment it is essential that the carbon dioxide be absolutely free from air. The luminous phenomena in the interior of the bag appear first when the solid 514 Scientific Intelligence. dioxide has formed a layer of from half a centimeter to a centi- meter in thickness. The author is continuing his investigations upon these phenomena.—Ber. Berl. Chem. Ges., xxiv, 1031, April, 1891. G. F. B. 4. On the Molecular Formula of Hydrogen Fluoride.—Pa- TERNO and PERATONER have determined the molecular mass of hydrogen fluoride by means of the lowering of the freezing point which it produces, the apparatus being the one ordinarily em- ployed for this purpose, except that it was made entirely of platinum. ‘The thermometric vessel was contained in a platinum tube, closed at its lower end and extending nearly to the bottom of the apparatus, being fastened to the cover. The space between the thermometric vessel and the walls of the tube was filled with mercury. After a series of comparative experiments proving this apparatus to give results coinciding with those obtained with a glass apparatus, it was applied to the determina- - tion of the molecular mass of hydrogen chloride in aqueous solu- tions of various strengths; and the results led uniformly to the formula HC]. On repeating the experiments with hydrogen fluoride however, the molecular mass obtained corresponded always to the doubled formula H,F,. Whether for more dilute solutions still this double molecule will split into two simple ones, farther experiments must determine. This result confirms the conclusion reached by Mallet by the vapor density method.— Ber. Berl. Chem. Ges., xxiv, (Ref.) 298, April, 1891. GFE 5. On the Extraction of Oxygen from the Air.—KassneEr has recently given further particulars concerning his process for ex- tracting oxygen from the air on a commercial scale, based on the successive formation and decomposition of calcium plumbate. He now finds that in producing this plumbate, it is better to use a slight excess of calcium carbonate, say five per cent. Two molugrams (a molugram is the molecular mass in grams) of calcium carbonate, with this excess, is heated with one of lead oxide ; and a resulting spongy product is obtained in this way, in which nearly the whole of the lead oxide is converted into the plumbate. The calcium carbonate is used in the form of lime- stone and it has been found unnecessary to stir the materials during the heating, which may be effected in an ordinary reverb- eratory furnace well supplied with air. To recover the oxygen the author heats the calcium plumbate in the presence of carbon dioxide, when the following reaction takes place: Ca,PbO,+ (CO,),=(CaCO,), + PhO+0. So that the process is a continuous one, the quantity of oxygen obtainable from a given quantity of charge being unlimited. Since the formation of the plumbate requires only a few minutes, and since its decomposition by the carbon dioxide is complete, the author thinks this process preferable to those of Boussingault and Brin ; especially since the value of the material, the cost of the plant and the working expenses are extremely small.—Dzéngl. J., eclxxviil, 468; J. Chem. Soc., 1x, 392, April, 1891. G. F. B. Chemistry and Physics. 515 6. On Sodium-amine and Di-sod-ammonium chloride.—Joan- nis has observed that at ordinary temperatures, sod-ammonium slowly decomposes into hydrogen and sodium-amine (sodamine) ; this decomposition tending toward a limit determined by the pressure of the hydrogen evolved. The sod-amine, NH,Na, appears in small colorless transparent crystals ; while that noticed by Gay Lussac was amorphous and of a blue or green color. The crystals dissolve in water with a hissing noise but without the evolution of gas. Disodium-ammonium chloride, NH,Na,Cl is an unstable compound which is obtained, mixed with sodium chloride, when sodium is treated with an excess of sodium chlo- ride in presence of liquefied ammonia, insufficient in amount for complete solution of the salt. On washing with liquid ammonia this compound decomposes into sodium chloride which dissolves and into sodamine which is left. By water it is broken up into ammonia, sodium hydrate, and sodium chloride.— C. #., exii, 392 ; Ber. Berl. Chem. Ges., xxiv, (Ref.) 292, April, 1891. Gi-Bo 8 7. Velocity of electrical waves in insulating fluids.—Maxwell has shown that the relation 2’= yp is a consequence of his electro- magnetic theory of hight. In this formula » is the rate of the velocity of the wave in a vacuum to that in the substance ex- amined and yp is its dielectric constant. L. Arons and H. Rev- BENS, employing Hertz’s method of studying electromagnetic waves, have examined the relation given by Maxwell and find it very nearly fulfilled in the case of the four fluids investigated by them.—Ann. der Physik und Chemie, No. 4, 1891, pp. 581-592. ce: 8. The telephone in an optical apparatus for measurement of electrical currents—Max Wi1EN employs the movement of the telephone diaphragm to measure both constant and alternating currents and prefers this instrument to the usual form of dyna- mometer. The iron diaphragm of the telephone is replaced by a thin metallic plate similar to those used in aneroid barometers. A piece of iron is placed upon this diaphragm opposite the pole of the telephone magnet and the movement of the diaphragm is communicated by a simple lever arrangement to a small mirror, which deflects the excursions of a spot of light into the field of view of a telescope. The amplitude of the movement of the spot of light is a measure of the current strength. The author dis- cusses the accuracy of the indications and shows that quantitative results can be obtained by this simple instrument.—Ann. der Physik und Chemie, No. 4, 1891, pp. 593-623. Feu 9. Photography of the ultra red rays.—In a communication to the Royal Society, March 12, Mr. Groraxr Hiaes stated that the alzarine blue S possesses in a high degree sensitive giving proper- ties for rays throughout the region comprised between wave- lengths 6200 and 8000, and does not like cyanin lower the sensi- tiveness to the violet and ultra violet. The method of preparation of the alzarine was described. With a slit 1/1000 inch in width and an exposure of forty minutes results have been obtained in the 516 Scientific Intelbigence. . region of great A of the second order, which possess all the detail and definition usually so characteristic of the violet end.— Nature, April 2, 1891, p. 525. BB 10. Lecture experiment on magnetic screening of conducting media.—J. J. Borneman describes the following experiment. A Lecher’s tube (Ann. der Physik und Chemie, xli, p. 850) is put by means of two cork rings into another large (4 cm. diam.) glass tube, with a crane on one end. Holding the tube in one hand, and approaching it to a wire in which electrical waves are pro- duced, a continuous lighting of the tube is seen. If the outer tube is filled with dilute sulphuric acid the light disappears. This is not the case when the outer tube is filled with water.— Nature, April 23, 1891. Slt II. GroLocy AND NATURAL HIsTORY. 1. Eruption of Kilauea.—The Daily Pacific Commercial Ad- vertiser of April 30th reports the following additional facts: “The breakdown is slightly larger than the one of 1886. It also differs from the one of 1886 in the following respects: in 1886 the fire appeared to have entirely gone out, there seemed to be little steam left, and for three months the crater was absolutely dead and cold, with the exception of the still warm lava which had run out prior to the breakdown. The lava then came back slowly, and it was considerably over a year before the whole basin filled up again. The breakdown of 1891 left hot lava still to be seen in the cracks around the edge of the breakdown, and dense clouds of vapors, steam and intense heat arising at several points from the bank. After a lapse of only three weeks the molten lava again appeared in the pit, and it is now filling up rapidly. The news brought by the steamer W. G. Hall was that up to the 26th inst. the bottom:of the pit had filled up about 100 feet, and a lake of liquid lava formed some 250 to 300 feet in diameter. This is the result of only ten days’ action. The bottom of the pit was steadily rising and the size of the lake increasing, and activity showing itself at new points every day. The illumina- tion was very bright, being visible at night at Punaluu, thirty miles away.” 2. Geological Survey of Ohio.—First Annual Report under the third organization by Edward Orton, State Geologist. 330 pp. Svo.—This very valuable report, chiefly by Professor Orton, treats of the origin and accumulation of mineral oil and natural gas, and of the Trenton and Clinton limestone and other rocks in Ohio, as sources of these materials. The chapters on these topics are preceded by one on the general geological structure of Ohio. The report is accompanied by two maps of the oil fields and gas fields. It closes with a chapter on the measurement of natural gas in gas wells, pipe lines, ete., by S. W. Robinson. 3. Iron Ores of Minnesota by N. H. Wincueut and H. V. WINcHELL. Bulletin No. 6 of the Geological Survey of Minne- sota, 420 pp. 8vo. With a geological map, 44 plates and 26 Geology and Natural History. 517 illustrations in the text. Minneapolis, 1891.—This volume treats, as the title-page further states, of the geology, discovery, devel- opment, qualities and origin of the ores, and of comparison with those of other iron districts. The rocks are described with some detail, colored microscopic sections given of several of them, and the age of the deposits 1s discussed at length. One of the inter- esting plates of the volume represents the famous Greenland mass of iron found embedded in basalt and weighing 19 tons, now in the museum of the Royal Academy at Stockholm. 4. The Tertiary Insects of North America; by Samur. H. ScuppER, U. 8. Geol. Surv. of the Territories, F. V. Hayden. Vol. xiii, pp. 734, Plates I-X XVIII. Washington, 1890.—This volume brings the subject of fossil Tertiary insects into promi- nence as a department of American paleontology. Formerly, it was impossible to make any general comparison between the American and Kuropean faunas, as the former was meager both in specimens and species. Owing to the rapid geological explora- tion of the West, and to the labors of the author of this mono- graph, the lack of material and of detinite knowledge have both been removed. Moreover, as the insect-bearing rocks are so ex- tensive, and have been investigated at so few localities, it is evident that further researches will result in a richer and more varied fauna than has yet been developed elsewhere. Six hundred and twelve species are described, divided among the orders as follows: Myriapoda 1, Arachnida 34, Neuroptera 66, Orthoptera 30, Hemiptera 266, Coleoptera 112, Diptera 79 Lepidoptera 1, and Hymenoptera 23. By far the most abundant fauna occurs in the Tertiary lake basin at Florissant, Colorado. Some of the higher orders of insects are more fully represented than is indicated in the enumeration of species. Their descrip- tion is reserved for the acquisition of more and better material. Other localities yielding fossil insects and included in the volume are: Green river, Fossil and Horse Creek, Wyoming; the vicinity of Quesnel, British Columbia; Scarboro, Ontario; and Port Kennedy, Pennsylvania. (Gls, 138) 5. Trilobites of the Upper Carboniferous of Kansas.—The Kansas City Scientist—a popular scientific monthly of 16 pages 8vo, made the official organ of the Kansas City Academy of Science—contains, in its March number, an article by 8S. G. Hare on species of Phillipsia, illustrated by a plate; and the February number contains an account of foot-prints from the Upper Carbo- niferous, by E. Butts. 6. An Introduction to the study of Petrology: The Igneous Kocks; by Freprrick H. Harcn. 128 pp. London and New York, 1891 (Swan Sonnenschein & Co.; Macmillan & Co.) This little book will be found useful by those desiring a concise account of the minerals which are present in the various types of igneous rocks and of the composition and occurrence of these rocks themselves. The space is about equally divided between these two parts, and the descriptions are probably as satisfactory as is possible where the subjects are treated with such brevity. 518 Scientific Intelligence. 7. Sinopsis Mineralégica 6 Catalogo descriptivo de los Min- erales por CARLOS F’. DE LANDERO. pp. 1-432. México, 1888. This is an alphabetical list of the various mineral species, giving brief descriptions with also numerous synonyms. It will be useful not only at home but wherever a knowledge of the Spanish and local Mexican names of minerals is needed. 8. New Meteorites—Mr. Edwin E. Howell gives descriptions of a number of new meteorites in vol. 1 of the Proceedings of the Rochester Academy of Science, illustrated by figures (part of which have been used in this Journal, vol. xl, p. 223). They are named the Welland Meteorite, from Welland, Ontario, Canada; the Hamilton County, from Texas; the Puquios, from Copiapo, Chili; the De Cewsville, from Ontario, Canada; two from Ata- cama, Chili, called the Dofia Inez and the Llano del Inca; and from Chili three others, the El Chafiaralino, la Primitiva and the Calderilla. The Hamilton Connty meteorite weighs 179 lbs., and its largest diameter is 174 inches. A fine plate printed from the iron exhibits grandly the Widmanstiatten figures. 9. Die Protoplasmaverbindungen zwischen benachbarten Ge- webeselementen in der Pflanze ; by F. Krenitz-Geriorr. (Bot. Zeit., 1891, Nrn. 1-5, Taf. I-I1).—The continuity of protoplasm in adjacent cells of vegetable tissue has since its discovery been a subject of the greatest interest and significance. Through this new and unexpected feature of plant-anatomy it has been hoped that hght might be thrown upon a host of physiological processes hitherto unexplained; and the importance thus attached to the histological fact has very naturally made the subject an alluring one for original investigations. Perhaps, indeed, no point of plant-anatomy has so often, within the last few years, been chosen as a subject for special study, nor in most cases proved so barren of new results. Since the appearance of Gardiner’s papers a number of new instances of the phenomenon in question have, it is true, been observed and recorded. Few details, however, have been added to our knowledge of individual cases, nor have the methods employed in the treatment and staining of preparations been essentially improved. Russow’s highly interesting hypothe- sis that the threads uniting the protoplasm in adjoining cells arise from the delicate fibrille observed between the nuclei in cell-division, has been neither confirmed nor refuted; and in regard to the physiological significance of the continuity of pro- toplasm theories are as conflicting as ever. The present paper by Kienitz-Gerloff, treating the subject both in its anatomical and physiological aspects, is therefore especially welcome. After a brief historical sketch the author proceeds to consider the different ways of treating sections to bring out clearly the connecting threads of protoplasm, and states that he has met with the best success by placing sections of fresh material in a solution of potassic-iodide to fix the protoplasm with but little contraction, before such reagents as sulphuric acid or chlor- iodide of zine are employed to act upon the cell-walls. This is Geology and Natural History. 519 Terletzki’s modification of the earlier methods. In the case of succulent plants it was found advantageous to dip the parts to be sectioned in boiling water and then harden them in absolute alco- hol. As a coloring agent Hoffmann’s aniline blue was chiefly employed, but the combination of this staining agent with picric acid, so highly recommended by Gardiner, was found to give too faint a tint—an experience we believe, which has been shared by others. Especial difficulty was found in coloring, where the cell- walls were cutinized, and in such cases a strong solution of methyl- violet gave the most satisfactory results. As a mounting agent glycerine proved useless, while Damar and Canada balsam are recommended. In a systematically arranged list the author enumerates some sixty species, from the Hepatice upward, which have been inves- tigated by him, and indicates in each case the elements between which protoplasmic threads were observed. As the tissues in and between which the continuity of protoplasm has been de- tected embrace nearly every kind of histological element, the con- clusion—already stated by others upon a less secure basis of observation—is drawn that all the elements in the higher plants are so connected. A single exception, however, is made in the case of the guard-cells of the stomata, the walls of which accord- ing to Kienitz-Gerloff are entirely free from perforating threads. The morphology and origin of the threads are excellently dis- cussed and the phenomena observed are well illustrated in a num- ber of figures. Details of course cannot be given here. It may be mentioned that the spindle-shaped enlargements of the proto- plasmic threads, so frequently observed near their middle but not altogether confined to that region, are plausibly explained on the ground that some of the lamellz of the cell-walls, notably those near the middle, are much less strongly swollen than others by such reagents as sulphuric acid, and therefore exert less pressure upon the penetrating threads. The protoplasm accordingly re- mains in greater quantity at these points. Our attention is also called to the fact that the connecting threads as they exist in nature, are doubtless much larger than they appear after treat- ment with reagents employed to bring them into view. Both the morphological descriptions and accompanying figures render Russow’s theory, just mentioned, very doubtful. Its disproof however is not altogether conclusive. Of especial interest is the treatment of the physiological aspect of the continuity of protoplasm, and here Kienitz-Gerloff favors strongly the theory of Kohl and Wortmann, that ‘a transference of protoplasm and the substances it contains really takes place from cell to cell by means of the threads. This view has been opposed by various observers, most recently by Noll and Zimmer- mann, who are inclined to consider the function of the continuity rather the communication of shock or impulse. Of the several very plausible reasons which Kienitz-Gerloff gives for believing that a transference of matter is effected by the structures ip # ei 520 Miscellaneous Intelligence. question we may only mention a curious negative argument from the guard-cells of stomata. In the autumn, as is well-known, the organic contents of the cells in deciduous leaves retire in great part into the stem, but in the guard-cells alone the protoplasm remains in tact even after the fall of the leaf. As we have just seen, these are the only cells which possess no protoplasmic connection with the other elements, and the inference is easy that: this is why their contents are not withdrawn. Reasoning from the converse it appears probable that the connecting threads among the other elements are the structures active in removing the organic substances from cell to cell, and finally out of the leaf into the stem. These facts taken alone would have but little weight but in conjunction with various other phenomena furnish a particularly interesting bit of evidence. The article closes with an excellent bibliography of the subject. Bis: 10. Protoplasmaverbindungen bei Algen ; (Berichte der deutsch. bot. Gesellsch., ix, pp. 9-16).—In a paper of this title Dr. F. G. Kout describes a series of observations upon the continuity of protoplasm in various cryptogams ranging from the Conjugate to the ferns, thus neatly supplementing the work of Kienitz-Ger- loff just discussed. Kohl’s methods of bringing the connecting threads to view are very interesting, since they are novel as applied for this purpose. Instead of using some reagent to act upon the cell-wall, he produces a slow plasmolysis, employing a solution of tannin-anilin (as recommended by Loeffler to show the cilia of bacteria), and then, after staining the preparations, em- ploys dilute glycerine to remove the coloring matter from the cell-walls. The well-known Spirogyra, which has been studied from so many different points of view, is once more made to do service as a typical example, and the continuity of the protoplasm in adjoining cells of its filaments is described and figured in detail. Kohl states further that he has observed similar phe- nomena in Cladophora, Ulothrix and other related forms. While in some of the alge, notably in certain Floridee the continuity of the protoplasm can be very readily demonstrated,—indeed it was here that it was first observed—there has been considerable doubt as to the extent to which the cells of the Mucoidee are thus connected. As examples of the latter group Kohl studied Himanthalea lorea and several species of Fucus. He states that by the use of the method just described he has been able to dem- onstrate a general continuity of protoplasm between the various cells of these plants; and that the phenomenon is by no means confined, as some have supposed, to the so-called sieve-hyphe. B. L, RB. III. MiscELLANEOUS SCIENTIFIC INTELLIGENCE. 1. The Journal of Comparative Neurology. A Quarterly Periodical devoted to the Comparative Study of the Nervous System. Edited by C. L. Herrick, Professor Biol. Univ. Cin- cinnati. 106 and xviii pages, 8vo Cincinnati, Ohio.—This first Miscellaneous Intelligence. 521 number of this new quarterly shows capacity in the editor to do well his part in conducting it. The first two papers, covering 35 pages, are by Prof. Herrick: the first, “Contributions to the comparative morphology of the central nervous system,” with plates I-IV, and the second, ‘Topography and histology of the brain of certain reptiles, with plates IX-X. Another article, over 50 pages in length, by C. L. Twines, treats of the morph- ology of the Avian brain, and is illustrated by plates V to VIII. In addition there are many notes from other journals, and a list of new publications, besides a statement by the editor of “the problems of comparative neurology,” setting forth the range of especially important subjects, which it is the object of the journal to elucidate. On account of the high character of the journal and the great importance of the field it covers, it deserves liberal support. 2. A Journal of American Ethnology and Archeology. Editor, J. WatterR Frewses. Vol. I, 132 pp. Boston and New York, 1891 (Houghton, Mifflin & Co.).—The first volume of this new journal gives gratifying promise as to the interest and value of the series which it commences. The leading article by the editor, Mr. Fewkes, is upon some summer ceremonials at Zuni Pueblo, giving results obtained in connection with the Hemenway Southwestern Archeological Expedition. It is liber- ally illustrated, and gives a very interesting account of some of the dances and other ceremonies of this curious people. A second paper is on Zui melodies by Benjamin Ives Gilman, accompanied by musical scores. A third paper, also by the editor, is on a reconnoisance of ruins in or near the Zuii reservation, with maps and other illustrations. The publishers have made the appear- ance of the volume very attractive. (Price two dollars). 3. Helmholtz Celebration and Medal.—Steps are being taken to celebrate the seventieth birthday of Professor von Helmholtz, which occurs on August 31st. A marble bust of Professor Helm- holtz is being made which will be presented to him on that occasion, and a fund is being raised the income of which is to be applied, primarily, to the bestowal of a Helmholtz medal on eminent investigators of all nations in the fields of Professor Helmholtz’s activity. An international committee, which has been formed to carry out these schemes, solicits contributions, which may be sent to the committee’s bankers, Mendelssohn & Co., Berlin. Professor Henry P. Bowditch of Harvard University will forward the contributions of such as may find it more con- venient to send to him, with the names of the contributors, to the bankers appointed by the committee. We understand also that an especial movement has been started among ophthalmologists and otologists of this country and Canada, whose contributions are received and forwarded by Dr. Herman Knapp of New York. All contributions should be sent as soon as possible. 4, National Academy of Sciences.—The following is a list of papers accepted for reading at the meeting held at Washington, April 21-24: 522 Miscellaneous Intelligence. A. S. PAacKArD: Further studies on the brain of Limulus Polyphemus. S. P. LANGLEY: On aerodromics. F. H. BigELow: The Solar Corona, an instance of the Newtonian potential in the case of repulsion. J. S. Brttryes: Report on the human bones of the Hemingway collection in the U. S. Army Medical Museum, prepared by Dr. Washington Matthews, WS: Ae A. A. MICHELSON: Application of interference methods to spectroscopic meas- urements. H. S. PritcHEeTT: The Corona from photographs of the eclipse of Jan. 1, 1889. Lewis Boss: Stellar motion problems. IRA REMsEN: Effect of pressure and temperature on the decomposition of diazo-compounds. Researches on the double halides. M. CarEy LEA: Allotropic silver; note on a paper by M. G. Lippmann. H. A. RowiLanD: On the yttrium earths, and a method of making pure yttrium. E. D. Core: On the distribution of colors in certain North American reptiles. THEO. GILL: The taxonomy of the apodal fishes. W. K Brooks and E. G. CONKLIN: Researches on the embryology of mollusks. Report of the Watson Trustees, and Presentation of the Watson Medal to Prof. Arthur Auwers of Berlin. 5. Magnetite Ore Districts of Brazil—Erratum.—Dr. O. A. Derby informs the Editors that the mineral occurring with the magnetite at Ipanema and referred to on page 316 of the April number as enstatite, has proved on further examination of better materiai to be barite. One specimen shows free crystals of barite upon its surface. Examen Quimico y Bacteriologico de las Aguas Potables por A. E. Salazar y C. Newman; con un capitulo del Dr. Rafael Blanchard. 513 pp. 8vo, with seven plates. London, 1890. Lecons sur les Métaux, Professées a la Faculté des Sciences de Paris, par Alfred Ditte, Professeur de Chimie a la Faculté. Premier Fascicule, Paris, 1891. The number system of Algebra treated theoretically and historically by Henry B. Fine, Ph.D. 131 pp.12mo. Boston and New York, 1891. Report of the Superintendent of the U. S. Coast and Geodetic Survey for the year ending June, 1888, pp. 566. 4to, Washington, 1889. Determinations of Latitude and Gravity for the Hawaiian Government, by E. D. Preston, pp. 563. 4to, Washington, 1890. (United States Coast and Geodetic Survey, Appendix 14.) The International Astrophotographic Congress and a Visit to Certain European Observations and other Institutions, by Albert G. Winterhalter, pp. 354. Ato, Washington, 1889. (Washington Observations, 1885, Appendix I.) Magnetic Observations at the United States Naval Observatory, 1888 and 1889, by Ensign J. A. Hoogewerff, U. S. Navy, pp. 100. 4to, Washington, 1890, (Washington Observations, 1886, Appendix I.) Saturn and its Ring, 1875-1889, by Asaph Hall, Prof. of Mathematics, U.S. Navy. pp. 22. 4to, Washington, 1889. (Washington Observations, 1885, Ap- pendix II.) Brachiopoden der Alpinen Trias von A. Bittner, pp. 325. 4to, Wien, 1890. (Alfred Holder, Vienna Academy.) Miscellaneous Intelligence. 523 OBITUARY. JosEPpH Lrmpy.—Dr. Joseph Leidy, the eminent Comparative Anatomist, Zoologist and Paieontologist, died at Philadelphia on the 30th of April. He was born in the same city on the 9th of September, 1823. His father was a native of Montgomery County, Pa., but his ancestors on both sides were Germans from the valley of the Rhine. While yet a school-boy, minerals and plants were eagerly collected and studied, and also anatomical dissections were begun, a barnyard fowl] being the first subject. He entered the Medical School of the University of Pennsyl- vania in 1840 and devoted his first year to practical anatomy. Having taken his medical degree in 1844, he became the next year, then 21 years of age, Prosector to Dr. Horner, Professor of Anatomy in the university ; and at the death of Dr. Horner, in 1853, he was appointed his successor. In 1844 he made the many remarkable dissections of terres- trial mollusks, the drawings of which cover sixteen plates and illustrate thirty-eight species in Dr. Binney’s fine work on the Terrestrial Mollusks of the United States—showing in all not only remarkable power as an anatomist entitling him to high rank, as Dr. Binney remarks, among philosophical zoologists, but also great skill as a draftsman. Thus, from the first, Dr. Leidy was the thorough, minutely accurate and untiring investigator. After the publication of Dr. Binney’s work in 1845, he was elected a member of the Academy of Natural Sciences of Phila- delphia ; and from that time he was its most active member, hardly a volume of its publications appearing without one or more papers on the results of his researches. Dr. Leidy’s contributions to Zoology and Comparative Anat- omy have a wide range. The Lower Invertebrates occupied a large share of his time. Besides multitudes of short papers, he published in 1853, a work of 67 pages, illustrated by ten plates, on “A Flora and Fauna within Living Animals ”—of the botan- ical part of which Dr. Gray said in this Journal—“a contribu- tion of the highest order, the plates unsurpassed if not un- equalled by anything before published in the country.” In 1879 appeared his large quarto volume on the fresh-water Rhizopods of North America, containing 48 colored plates, the material of which was in part collected during two seasons in the Rocky Mountain region under the auspices of the Hayden Exploring Expedition. As a portraiture of the Doctor over the little mem- berless species, we quote from his concluding remarks: “The objects of my work have appeared to me so beautiful, as repre- sented in the illustrations, and so interesting as indicated in their history which forms the accompanying text, that I am led to hope the work may be an incentive, especially to my young countrymen to enter into similar pursuits. ‘Going fishing ?’ How often the question has been asked by acquaintances as they have met me, with rod and basket, on an excursion after mate- 524 Miscellaneous Intelligence. rials for microscopic study. ‘ Yes,’ has been the invariable an- swer, for it saved much detention and explanation; and, now, behold, I offer them the result of that fishing. No fish for the stomach, but as the old French microscopist, Joblet, observed, ‘some of the most remarkable fishes that have been seen,’ and food fishes for the intellect.”” He delighted in his work because he knew that there was no fact in connection with the structure and functions of the simplest of living things that was not pro- found and comprehensive, that did not reach up through all species to the highest. . The Vertebrates described by him were mainly fossil species. Dr. Leidy has the honor of having opened to geological science a general knowledge of the remarkable mammalian fauna of the country, and especially that of the Rocky Mountain region. Species had been before described, but through him the general range of North American species began to be known, In 1847, he published on the fossil Horse; in 1850, on the extinct species of the American Ox; in 1852, and 1854 on the extinct Mammalia and Chelonia from Nebraska Territory, collected during the sur- vey under Dr. D. D. Owen; in 1855, on the extinct Sloth tribe of North America; in 1869, on the extinct Mammalian fauna of Dakota and Nebraska, a thick quarto volume published by the Philadelphia Academy of Sciences, based on materials that had been gradually and continuously accumulating for the last twenty years; and in 1873 contributions to the extinct Fauna of the Western Territories, making the first quarto volume of the Hay- den Survey. The last two works mentioned contain over 800 pages of text and nearly 70 of plates. Besides these large works numerous short papers from time to time appeared. Dr. Leidy retired from this particular field when questions of priority began to start up, it being no part of his nature to quarrel, and having the firm belief, as he said, that the future would award credit where it was deserved. His work among the fossil Vertebrates extended also to Fishes, Batrachians and Reptiles of different geological periods, and among his contribu- tions, that on the Reptiles of the Cretaceous period of 1865, pub- lished by the Smithsonian Institution, covers 136 pages and is illustrated by 20 plates. | Dr. Leidy’s zeal never flagged; his labors came to an end only with his sudden death. Eight days before, he delivered his last University lecture. Beginning original work before he was twenty, his published papers and larger books continued to appear through half a century and number over nine hundred. As is well said in one of the many tributes to him published in the Philadelphia papers after his decease : “ He possessed to the end of a long career the freshest capacity of seeing the opportunities and openings for discovery and re- search offered by familiar phenomena. His vast store of exact and diverse knowledge in the whole wide field of animate na- ture was under the command of a logical judgment and synthetic Miscellaneous Intelligence. 525 powers which saved him from vagaries. These high intellectual powers were served by an untiring capacity for work and equal skill of eye and hand. “These are rare gifts; but they are none of them, nor all of them put together, as rare as his character. His simplicity, his transparent sincerity, his ingenuous anxiety to serve science and to serve science alone, his freedom from all desire for the rewards, the honors and the recognition after which lesser men go a-wan- dering, were as remarkable as his scientific powers.” Never were words more truthful. Honors came to him from all parts of the civilized world, and more because unsought. Dr. Leidy leaves a wife and an adopted daughter. JoHN LEContr, Professor of Physics and Industrial Me- chanics in the State University at Berkeley, California, died on the 29th of April, aged 72 years. Professor LeConte, the oldest son of the naturalist, Lewis LeConte, was born in 1818 in Liberty County, Georgia. He was graduated from Franklin College, now the University of Athens, Georgia, when he was twenty years old, and from the College of Physicians and Surgeons in New York City three years later. He then entered upon the practice of medicine at Savannah where he remained for four years. In 1846 he was called to the Chair of Natural Philosophy in Frank- lin College, which he occupied until 1855. In the following year he lectured on chemistry at the College of Physicians and Sur- geons in New York City; in the same year he was made Profes- sor of Natural and Mechanical Philosophy in South Carolina College at Columbia, 8. C., a position which he held for thirteen years. In 1869 he was appointed Professor of Physics and Industrial Mechanics in the University of California, and this position he retained until 1881.. From 1876 to 1881 he held, in connection with his professorship, the office of President of the university, and at the expiration of that term he retired to the Chair of Physics, which he occupied until the time of his death. Professor LeConte’s energies were early devoted to medicine but later he turned toward physical science and in both depart- ments he made numerous contributions which have been pub- lished in the Proceedings of the American Association and in various scientific journals. Among those which have appeared in this Journal may be mentioned papers on the influence of musical sounds on gas jets; on the influence of solar light upon combus- tion; physical studies on the waters of Lake Tahoe; several papers upon various aspects of the phenomena of capillarity ; also on sound shadows in water. In 1857 he delivered a course of lectures on “‘ The Physics of Meteorology” before the Smith- -sonian Institution, in Washington, and in 1867 he read an im- portant paper on ‘The Stellar Universe” before the Peabody Institute, in Baltimore. His whole list of published writings includes about a hundred papers extending over a wide range of subjects. Am. Jour. Sci.—THIRD SERIES, Vou. XLI, No. 246.—JuUnNE, 1891. 39 526 Miscellaneous Intelligence. In 1879 he received the degree of LL.D. from the University of Georgia and the same year he was made a member of the National Academy of Sciences. A younger brother, Professor Joseph LeConte, also of the University of California, and closely associated with him through life, is well known as a seologist and physiologist. Jutius Erasmus Hinearp, late Superintendent of the United States Coast Survey, died at his home in Washington on the 8th of May, after a long and painful illness. He was the son of Theodore Erasmus Hilgard, an eminent German jurist, and was born in Zweibriicken, Bavaria, Jan. 7, 1825. He came to this country when ten years of age, and until 1843 resided in Belle- ville, Ill. In that year he removed to Philadelphia, where he took up the study of civil engineering, and two years later he became one of the assistants of Professor Bache on the Coast Survey. In 1862 he was promoted to the position of assistant In charge of the Coast Survey Office. This position he held until 1881, when, upon the death of Captain Patterson, he was ap- pointed Superintendent ; increasing physical disability, however, interfered with the discharge of his duties and finally led to his resignation, which took effect in 1886. Dr. Hilgard’s active labors, for nearly forty years, were chiefly in connection with the development and administrative work of the Survey, and here he did very important and valuable service to science and to the country. He had charge of the con- struction and verification of the standards of weights and meas- ures, and was for some time engaged in preparing metric stan- dards for distribution to the several States. He was also engaged in researches and the discussion of the results in geodesy and in terrestrial physics and in perfecting methods and instrumental means connected with them. One of the most important pieces of work with which he was competed was the determination of transatlantic longitude in 1872; a result of this was to establish an important correction to the longitude of Paris as reckoned from Greenwich. ” ’ * * J A ~~. i \ ‘: Ve r ne y * ’ . * . - . r i - a * 4 . . i Plate XVII. Am, Jour. Sci., Vol. XLI, i891. Tm, ae, 7 on™ The sun Hypson and 400) Am ode: SCL BY " fi Am.Jour Sci.Vol XLI 189) MIDDLE ATLANTIC COAST REGION Scale 1:2000 000 Nautical Miles Statute Miles. eo. Hypsontetrial lines are given for heights of 150,300 und 400 yet above the Sea-level The sunken channels are indic horizontal shading. ated by Plate XVII. it ae BECK HR BROTHERS, No. 6 Murray Street, New York, Manufacturers of Balances and Weights of Precision for Chem- ists, Assayers, Jewelers, Druggists, and in general for every use where accuracy is required. PUBLICATIONS OF THE i a BALTIMORE. I. American Journal of Mathematics. 8. NEwcomp, Editor, and T. Crate, Associate Editor. Quarterly. 4to. Volume XII in progress. $5 per _ volume. II, American Chemical Journal.—I. REMSEN, Editor. 8 Nos. yearly. 8vo. Volume XI in progress. $4 per volume. III. American Journal of Philology.—B. L. GILDERSLEEVE, Editor. Quar- terly: 8vo. Volume X in progress. $3 per volume. IV. Studies from the Biological Laboratory.—Including the Chesapeake Zoological Laboratory. H. N. Martin, Editor, and W. K. Brooks, Asso- ‘ciate Editor. 8vo. Volume IV in progress. $5 per volume. V. Studies in Historical and Political Science.—H. B. Apams, Editor, Monthly. 8vo. Volume VII in progress. $3 per volume. VI. Johns Hopkins University Circulars.—Containing reports of scientific and literary work in progress in Baltimore. 4to. Vol. IX in progress. $1 per year. VII. Annual Report.— Presented by the President to the Board of Trustees, reviewing the operations of the University during the past academic year. VII. Annual Register.—Giving the list of officers and students, and stating the regulations, etc., of the University. Published at the close of the Aca- demic year. : ROWLAND’S PHOTOGRAPH OF THE NORMAL SOLAR SPECTRUM. New edition now ready. $20 for set of ten plates, mounted. OBSERVATIONS ON THE EMBRYOLOGY OF JNSEOTS AND ARACHNIDS. By Adam TT. Bruce. 46 pp. and 7 plates. $3.00, cloth. SELECTED MoRPHOLOGICAL MonoGRapus. W.K. Brooks, Editor. Vol. I. 3870 pp. and 51 plates. 4to. $7.50, cloth. THE DEVELOPMENT AND PROPAGATION OF THE OYSTER IN MARYLAND. By W. K. Brooks. 193 pp. 4to; 13 plates and 3 maps. $5.00, cloth. ON THE MECHANICAL EQUIVALENT OF Heat. By H. A. Rowland. 127 pp. 8vo. $1.50. A full list of publications will be sent on application. Communications in respect to exchanges and remittances may be sent to the Johns Hopkins University (Publication Agency), Baltimore, Maryland. 5 4 CONTENTS. Page Arr. LIII.—The Study of the Earth’s oieae by means of the Pendulam:“by,-H.°D. PRESTON. 22-5 9o oe 445° LIV.—Post- Glicut History of the Hudson. River Valley ; : by J. Ee Mernlbs oo 5 ae ee 460 | LV.—Alunite and Diaspore from the Rosita Hills, Colorado ; : by Wautman Cross) oso ye 2 ee 466 LVI.—Diaspore Crystals; by W. H. Mutvirie_._..--.-.- 475— LVII.—Combustion of Gas Jets under Pressure; by R. W. NY OD 3 Reh 8 oe ee 477 LVIII.—Allotropic Silver; by M. Canny Lea._---------- 482 - LIX.—Notes on the sub-marine channel of the Hudson River | and other evidences of Post-glacial Subsidence of the Middle Atlantic Coast Region; by- A. LinDENKOHL. (With Plate XV) 22 ee ae ee 489 LX.—Are there Glacial Records in the Newark System? by WD, GU RSBU Leeks a ee er 499 LXI.—A reply to Professor Nipher on “ The Theory of the Solar Corona”; by FP. Hy BighLOW,.\ 2% 22 3525" See 505 LXII.—Recent Eruption of Kilauea ; by W. T. Bricuam _- 507 LXIIl.—Turquois in Southwestern New Mexico; by C. H. WOW). Sieh eed oT Se LAS Le ek Ae ee ol 511 SCIENTIFIC INTELLIGENCE. Chemistry and Physics—Compressibility of Hydrogen, Oxygen and Nitrogen, AMAGAT: Osmotic Pressure, BOLTZMANN, 512.—Production of Electrification in the Preparation of solid Carbon dioxide, HAUSSKNECHT, 513.—Molecular Formula of Hydrogen Fluoride, PaTERNO and PERATONER: Extraction of Oxygen from the Air, KASSNER, 514.—Sodium-amine and Di-sod-ammonium chloride, JOANNIS: Velocity of electrical waves in insulating fluids, ARONS and REUBENS: The telephone in an optical apparatus for measurement of electrical currents, Max WEIN: Photography of the ultra red rays, G. Hiees, 515.— Lecture experiment on magnetic screening of conducting media, J. J. BORGMAN, 516. Geology and Natural History—Eruption of Kilauea:’ Geological Survey of Ohio: Iron Ores of Minnesota, N. H. WINCHELL and H. V. WINCHELL, 516.— Tertiary Insects of North America, 8. H. ScuppErR: Trilobites of the Upper Carboniferous of Kansas: An Introduction to the study of Petrology, F. H. Hatou, 517.—Sinopsis Mineralogica 6 Catalogo descriptivo de los Minerales por C, F. DE LanpERO: New Meteorites: Die Protoplasmaverbindungen zwischen benachbarten Gewebeselementen in der Pflanze, by F. KIENITZ-GERLOFF, 518. _—Protoplasmaverbindungen bei Algen, F. G. Kont, 520. Miscellaneous Scientific Intelligence—The Journal of Comparative Neurology, 520 —A Journal of American Ethnology and Archeology, Editor, J. W. FEWKES: Helmholtz Celebration and Medal: National Academy of Sciences, 521.— Magnetite Ore Districts of Brazil, 522. Obituary—JOSEPH LEIDY, 523; JoHN LEeConTE, 525; Jutius ERASMUS HILGARD, 526. INDEX TO VOLUME XLI, 527. | VT TELE ee aa eee Lip pp Peer pee -~ ] => 6 Kies ; MtaAa, ana yep 4 | Wyn 27H: im bak A © ripe epee eer ig ED pehniah SR ENR Sm | | pnldielad Wi | | ne aan: ky e.S&4a "Wu, N pale) asap? gonprasAbr: el alah vata Pints \y aaananye : | Vee *\e e af \- va ' 1 valle rm uy \ i \ MN we rea ORR OTRAe ie FNL ae gy yo Dh Anllls, me Ay Soh Uhh PT tS onl ‘hme ee) a awry, ; | yh, ‘a, . \e a Msnals La tt ial ie Pee eh) HIMPPVKLENGa ce osentta Ws Hal Wen Fea alle Ys weeny “ae pore ||| | Lal pee cane nal ET Pitti a Beelaas. “4a Rest e) 4... A-. aul Mo A otaay. TTY Mita Neebiakk Yavin ele alata ye es ero. eatitigs faante HNL. ay fMens,, aw Reng, Ardea Naya aes, ry, TTY Vy VARA Or Sle a 10) 0 me TW ys Me am WO SAD | [Leann ’ (lO val My gue Sey a rca STOTT IS t *332 SS SE Ne 48 sags mM ne Ae 1 rer el Gi | ry at | , fi, | o~d an Asdapaas, Nar’ an, pA TOT PLULET esi Pawan “ibe Ma SDs AN Hea She CRE ad WA Em a (A~ { - fete (hed Se a an ‘a Rae Mads wna \ yr & - gf ra tk, wnant ~ Aran ahs is at a B.. ya a ‘\\_ Lb Ane. af oy sAagse PERE Nei ocre coer aah YH Attire i nae { ta vVONT oO. ¢ WN ier ge hhh Wy Vee: Muy Aiaikn | 1, Ws an eae Patina || A ame UL Ne WRT | VO ty aia a £ ep par be. a : Alene <.m 1] os = MN rihastna Mga nant nN bry ON diate) Fiat , + ps \ : > N:P Nad Rye mh 4 ay a6 vita”! 3 Wh in eh . ~ APP an wr pane ow 9 LOTT TT DAP || | | Lae i Hyryriey abr wi U ee Sait ba feb Pal i La il wie! “aed spyard Wniored aga) EEE PD et LTTE PAs, ie t. \ A: ie emt ‘ | RT | "ee Awe a ey nd am Gaube PAs ~G ty cae te mt ve sae 94 © 4 naps yO?) M4 aha as a Pah ert ry Aap | Phir racy ant al DNA ee Hd mat LEAS bi bby S44,” Helin! Sug, NUR Ty | pres v MAI) a Neate ha A naa, rN Vn, Hin \ Neb piialannt uh Va @ ¥ ‘ ; ~ 2 i) { Ny 1 wry %, > t if GIDE ay ‘a LTT] iMaevteqn *’, We vvecve mapannse tan | fp au Ny sana VEY Ve. ge »®y eo at TT a® Ap bv teh owe Lane adit rg ik ae OY ol) Oe Psa Poe é Ar FY NA a, pi baealY pareve euvauptbres tt 7 eben AAA lar Rina hid, TL | » 79Q¢' . oe ee we ANN LN Yori = Sy ag eat f veces cm yy aye wae He aaa CY OPO RRP a4 Jyh in OT lalla ne ry . le ae 5 ee ‘5 SSScueqe, roe hea Stray ne 7%e, iuenuu