PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON. From June 16, 1870, to June 15, 1871. VOL? XIX: y ee / LONDON: PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. MDCCCLXXI. CONTENTS. VOL. XIX. No. 123.—June 16, 1870. Page On the Atmospheric Lines of the Solar Spectrum, in a Letter to the Presi- Ce ete mete tito lt, LCMNESSEY. 0.0. gi o'si< apa oie dhe oFerwsdie oe fea eas 08 On the Radiation of Heat from the Moon.—No. II. By the Earl of Rosse, ae Ee EEA cer leh cdot eatle Ci les cs ico salves 0 ie be 0 8 w fecsiciees< On Linear Differential Equations—No. III. By W.H. L. Russell, F.R:S. Observations with the Great Melbourne Telescope, in a Letter to Prof. Bprerlae emi S SC OUCUT cya 6 fda" 5 oye ey ol tiedeiese'e © 6) 4) e) 6 47o.9\0 nie e wlecenia)» Chemical and Physiological Experiments on living Cinchone. By J. Broughton, B.Sc., F.C.S., Chemist to the Cinchona-Plantations of the Serie AUR OE NI ICUs 3.00504) ht er Be, oak 8 vale Bia elcid ones aneuk wrelord oi @ wnaroerstabanens Researches on the Hydrocarbons of the Series Cn Han+2—VI. By C. Berea PPIieReNE BOBRUTC Tomi diet settee he eye = ol so ala ay milo o1'e(ain) ticle. aye" ss.) als) 2) s)ea sete 6 Formation of Cetyl-alcohdl by a singular reaction. By C.Schorlemmer . Researches in Animal Electricity. By C. B. Radcliffe, M.D............ : HSC OF Presents «2 2... ee wees SMeOUEE Maat 2 apa ch ouch eel easy eV oa) ascuied ies ai'ns cies : Communications received after the Session. On Approach caused by Vibration. By Frederick Guthrie.............. On Jacobi’s Theorem respecting the relative equilibrium of a Revolving Ellipsoid of Fluid, and on Ivory’s discussion of the Theorem. By I. Todhunter, M.A., F.R.S., late Fellow of St. John’s College, Cambridge. . On the Theory of Continuous Beams. By John Mortimer Heppel, M. Inst. C.K er ery oe 08 © © @ Remarks on Mr. Heppel’s Theory of Continuous Beams. By W. J. Macquorn ee Maite mi ipl) Wye WB Se aesc arene et puaueie 4 a’) a eyei'saiele. P-o.g nee vince sacar bee Researches into the Chemical Constitution of the Opium Bases.—Part IV. On the Action of Chloride of Zine on Codeia. By Augustus Matthiessen, F.R.S., Lecturer on Chemistry at St. Bartholomew’s Hospital, and W. MIS, On C MINGUS ELOSNITA Ls his hate da ab hed Ys Whe nase iead nace ek 14 35 42 56 68 Gal 1V : Page Experiments on the Action of Red Bordeanx Wine (Claret) on the Human Body. By E. A. Parkes, M.D.,F.R.S., Professor of Hygiene in the Army Medical School, and Count Cyprian Wollowicz, M.D., Assistant Surgeon, Army Medical Staff... 0000 ce eee selee cece en oe seals a 73 On the Mathematical Theory of Combined Streams. By W. J. Macquorn Rankine, C.E., LL.D., F.R.SS. Lond. and Edinb..... onto wt els ae 90 No. 124.— November 17, 1870. Researches into the Chemical Constitution of the Opium Bases.—Part IV. On the Action of Chloride of Zinc on Codeia. By Augustus Matthiessen, F.R.S., Lecturer on Chemistry at St. Bartholomew’s Hospital, and W. Burnside, of Christ’s Hospital. (See page 71.)..........0se su eee 94 Experiments on the Action of Red Bordeaux Wine (Claret) on the Human Body. By E. A. Parkes, M.D., F.R.S., Professor of Hygiene in the Army Medical School, and Count Cyprian Wollowicz, M.D., Assistant ~ Surgeon, Army Medical Staff. (See page 73.) ............ bare oe aoe 95 On the Mathematical Theory of Combined Streams. By W. J. Macquorn Rankine, C.E., LL.D., F.R.SS. Lond. and Edinb. (See page 90.) .... 95 On the Fossil Mammals of Australia.—Part IV. Dentition and Mandible of Thylacoleo Carnifex, with Remarks on the Argument for its Herbivority. By Prof. Owen, FBS. &e. 2...) cen es ie ie er 95 November 24, 1870. Communication from the Secretary of State for India relative to Pendulum Observations now in progress in India in connexion with the Great Tri- gonometrical Survey under the Superintendence of Colonel J. T. Walker 1. DASE OF 5 ern PAREN ssc a! WON On the Theory of Resonance. By the Hon. J. W. Strutt............006. 106 On the Aromatic Cyanates. By A. W. Hofmann, LL.D., F.R.S......... 108 November 30, 1870,» Anniversary Meeting : Reportof Auditors 33 sleL. A. 3. ee ‘ini «ato Soe 113 List of Fellows deceased, &. 13. ...... 6002004250 6 eee 113 ———— elected since last Anniversary «...... .. 7a . 114 Address of the President ..:.......-sisee+0e ees ie Presentation of the’ Medals s.2). s6.5. 2), Sa ae We ie ss 193 Election of Council and Officers. ..... 0024 s¢s50 «at a 128 Financial Statement .............0ece0eccecsc ent 129 & 130 ast of Presents. ......56ss0cscedeewscsensecds acu duas th 131 Account of the appropriation of the sum of £1000 annually voted by Par- liament to the Royal Society (the Government Grant), to be employed in siding the advancement of Science ,.......:...:.....,. se 135 Account of Sums granted from the Donation Fund in 1870.............. 145 No. 125,—December 8, 1870. Report on fe Bai Researches carried on during the Months of July, August, and September 1870, in H.M. Surveying Ship ‘Porcupine.’ By W. B, Carpenter, M.D., F.R.S., and J. Gwyn Jeffreys, F.R.S........... 146 Vv December 22, 1870. On the Extension of the Coal-fields beneath the Newer Formations of Eng- land; and the Succession of Physical Changes whereby the Coal-mea- sures have been reduced to their present dimensions. By Edward Hull, M. A., F.RS., F.G.S., Director of the Geological Survey of Ireland .... 222 On the Constitution of the Solid Crust of the Earth. By the Ven. John Henry Pratt, Archdeacon of Calcutta, M.A., F.R.S. ...........65. 223 Actinometrical Observations made at Dehra and Mussoorie in India, Octo- ber and November 1869, in a Letter to the President. By Lieut. J. H.N. eM a ce ia ia eco ag hc [5 guage ola YRS Al oe, vnjn cea P hele aneliee ea csi es 225 Page January 12, 1871. On Fluoride of Silver.—Part Il. By George Gore, F.R.S...........00.. 235 Some Experiments on the Discharge of Electricity through Rarefied Media and the Atmosphere. By Cromwell Fleetwood Varley Remar mccoy oie 6 236 Polarization of Metallic Surfaces in Aqueous Solutions, a new Method of obtaining Electricity from Mechanical Force, and certain relations be- tween Electrostatic Induction and the Decomposition of Water.’ By Cromwell Fleetwood Varley...... BR HRSA. 5 Shee et aT toe Sp Parana 243 January 19, 1871. On the Structure and Development of the Skull of the Common Frog (Hana temporaria). By W. Kitchen Parker, F.R.S. 2.00.6... eae 246 Method of measuring the Resistance of a Conductor or of a Battery, or of a Telegraph-Line ‘influenced by unknown Earth-currents, from a single Deflection of a Galvanometer of unknown Resistance. By Henry Manee, Superintendent Mekran Coast and Persian Gulf Telegraph Department, LED ELBE Us RIE COR Tee IRS core to eden Soares arse eg ok aC mer Teno eaeney tear 248 Measurement of the Internal Resistance of a Multiple Battery by adjusting the Galvanometer to Zero. By Henry Mance ............... cece eee 252 Modification of Wheatstone’s Bridge to find the Resistance of a Galvano- meter-Coil from a single deflection of its own needle. By Prof. Sir Wil- peredierh stoi Fy ic ge eee ysis ale gp eo Slaw ges Saeed ewe ee seee.s 253 On a Constant Form of Daniell’s Battery. By Prof. Sir William Thomson, LSS. one bo eee ca Ra ace Cie RR isa icra a se ac a 253 On the Determination of a Ship’s Place from Observations of Altitude. By ese WV ilar CP homsony. ERS .6 cco bd ele eels 6 bh weed siss 259 January 26, 1871. On the Mineral Constituents of Meteorites. By Nevil Story Maskelyne, M.A., F.R.S., Professor of Mineralogy, Oxford, and Keeper of the Mineral Department, [Eis it TAT rt Cush gna ele eg area Sa a 266 On the Organization of the Calamites of the Coal-measures. By W. C. Williamson, F.R.S., Professor of Natural History in Owens Callens) Man- SE UEEEEE co oo NURS GC RAC COORG CRS Si CO uO On Nr ane 268 On Approach caused by Vibration. A Letter from Prof. Sir W. Thomson, Pan), Poiessy doe: to Prot. Frederick Guthrie; BwAw: |. k.ccse eee cee es 271 REP CSCTI Gy feo ont, hee. te Ae ks Ts sa oe SEN 2a er eee. sal No. 126.—February 2, 1871. Page On Linear Differential Equations—No. IV. By W.H. L. Russell, F.R.S. 281 Measurements of Specific Inductive Capacity of Dielectrics, in the Physical Laboratory of the University of Glasgow. By John C. Gibson, M.A., and Thomas Barclay, M.A. oo... je. hea ws ved ss os err 285 On the Uniform Flow of a Liquid. By Henry Moseley, M.A.,.D.C.L., Canon of Bristol, F.R.S., and Corresponding Member of the Institute of PEACE GSES. SUP RPI BPN Ee er 286 February 9, 1871. On the Effect of Exercise upon the Bodily Temperature. By T. Clifford Allbutt, M.A., M.D. Cantab., F.L.S., Member of the Alpine Club, &c... 289 Observations of the Eclipse at Oxford, December 22, 1870. By John Phillips, M.A., D.C.L., F.R.S., Professor of Geology in the University Of Oxtord 00... sake eine mails bie dint ke erccueily keen 290 On the Problem of the In- and Circumscribed Triangle. By Prof. A. Cayley, RS aje dg w's) ee waa eit O64 are 9 Soe tye ldle Bye bie a Sees ce eee) or 292 On the Unequal Distribution of Weight and Support in Ships, and its Effects in Still Water, in Waves, and in Exceptional Positions on Shore. By E. J. Reed, C.B., Vice-President of the Institution of Naval Archi- * DEG oe PIA Ny, pe eto aera pe cl Re 5 “sa niece 6 oleh 6 oe 292 February 16, 1871. On some of the more important Physiological Changes induced in the Human Economy by change of Climate, as from Temperate to Tropical, and the reverse (concluded). By Alexander Rattray, M.D. (Edinb.), Surgeon -R.N., ELMS. “Bristol” et ees ies ee os Coe 295 On a Registering Spectroscope. By William Huggins, LL.D., D.C.L., EE e oie oe aje sgn vei tbo. v. 401618 ole ree sialon « Pls keh 317 February 23, 1871. On the Mutual Relations of the Apex Cardiograph and the Radial Sphyg- mograph Trace. By A. H. Garrod, of St. John’s College, Cambridge .. 318 On the Thermo-electric Action of Metals and Liquids. By George Gore, BT PRS 2 Sic bin aitliele le Sfeiera’e ips la lo Hashes: acne a sete. « fy cu eAlonatiote Rae ts ieee ae 324 No. 127.—March 2, 1871. Further Experiments on the effect of Diet and Exercise on the Elimination of Nitrogen. . By KE. A. Parkes, M.D, ERS... oan. 606 yeep eee 349 Magnetic Observations made during a Voyage to the North of Europe and the Coasts of the Arctic Sea in the Summer of 1870. By Capt. Ivan Belavenetz, I.R.N., Director of the Imperial Magnetic Observatory, Cronstadt. In a Letter to Archibald Smith, M.A., LL.D., F.R.S. .... 361 March 9, 1871. Results of Seven Years’ Observations of the Dip and Horizontal Force at Stonyhurst College Observatory, from April 1863 to March 1870, By PH NLCY: 19. J, CULV oe bt vies 9 bpp ee 4 bo Oe ae peel nn soe ee 368 vil Page Preliminary Notice on the Production of the Olefines from Paraffin by Dis- tillation under Pressure. By T. E. Thorpe, Ph.D., Professor of Chemistry in Anderson’s University, Glasgow, and John Young ..............-. 37 Contributions to the History of the Opium Alkaloids. Part I—On the Action of Hydrobromic Acid on Codeia. By C. R. A. Wright, D.Sc... 371 March 16, 1871. Description of Ceratodus, a genus of Ganoid Fishes, recently discovered in rivers of Queensland, Australia. By Albert Gunther, M.A., Ph.D., SIME a ey horse ot atete sbi a es 28a Sas), eres vale agin, aes eve vale ORs O17 On the formation of some of the Subaxial Arches in Man. By George W. Callender, Assistant-Surgeon to, and Lecturer on Anatomy at St. Bar- PemD MRM EMEL CH SIOUE AN agten sls ais oles pis 5, so Wels dv a sp0.e sjsce eich es. cele qe oa aia Pleo 380 March 23, 1871. Experiments on the Successive Polarization of Light, with the in of a new Polarizing Apparatus. By Sir Charles Wheatstone, F.R.S. .. 381 On an approximately Decennial Variation of the Temperature at the Obser- vatory at the Cape of Good Hope between the years 1841 and 1870, viewed in connexion with the Variation of the Solar Spots. By E. J. Stone, F.R.S., Astronomer Royal at the Cape of Good Hope. In a eae ROME PPE MEL OUGETIG co! «5 sbi te vic p'a o1>!0 alo cee viele 0 as 6! 8 era's Pied avecals 389 Résumé of two Papers on Sun-spots:—“On the Form of the Sun-spot Curve,” by Prof. Wolf; and “On the Connexion of Sun-spots with Planetary Configuration,” by M. Fritz. By B. Loewy .............. 392 ‘March 30, 1871. Experiments in Pangenesis, by Breeding from Rabbits of a pure variety, into whose circulation blood taken from other varieties had previously been largely transfused. By Francis Galton, F.R.S. ...............- 393 Contributions to the History of Orcin.—No, I. Nitro-substitution Com- pounds of the Orcins. By John Stenhouse, LL.D., F.R.S., &......... 410 ES PMUMMP ETE GROILL SI rd ns te. sesh a er e eo a eta Natok eed eae ln a oe ee 418 No. 128.—April 20, 1871. Note on the circumstances of the Transits of Venus over the Sun’s Disk in the years 2004 and 2012. By J. R. Hind, F.R.S. On the Existence and Formation of Salts of Nitrous Oxide. By Edward La LOSS, LL 0 B ESA ets as te ne ee OL cree ee naot sue ses ae) cath eg sill gato 425 Research on a New Group of Colloid Bodies containing Mercury, and cer- tain Members of the series of Fatty Ketones. By J. Emerson Reynolds, Member of the Royal College of Physicians, Edinburgh, Keeper of the Mineral Department, and Analyst to the Royal Dublin Society ........ 431 April 27, 1871. The Bakerian Lecture.—On the Increase of Electrical Resistance in Con- ductors with rise of Temperature, and its application to the Measure of Ordinary and Furnace Temperatures; also on a simple Method of Bee lectrical Resistances. By Charles William Siemens, F.R.S, “2G Ce NENG whee CL ces Cerf 0S Phage MERE GR ee 443 vill Pa, On the Change of Pressure and Volume produced by Chemical Combina- tion... By M. Berthelot), 2 gi3)2% esuled. es ss «soe 445 Remarks on the Determination of a Ship’s Place at Sea. In a Letter to Professor Stokes. By G. B. Airy, LL.D. &c., Astronomer Royal...... 448 May 4, 1871. On the Structure and Affinities of Guynza annulata, Dunc., with Remarks upon the Persistence of Paleozoic Types of Madreporaria. By P. Martin Duncan, M.B. Lond., F.R.S., Professor of Geology in King’s College, MA ONGON. +) + o-oo: 20. o ener or e's’ ciara’ pintara) e's slahe sev al « «5 we wear oe rr 450 On the Molybdates and Vanadates of Lead, and on a new Mineral from Leadhills. By Professor Dr. Albert Schrauf, of Vienna.............. 451 May 11, 1871. An Experimental Inquiry into the Constitution of Blood, and the Nutrition of Muscular Tissue. By William Marcet, M.D., F.R.S., Senior Assis- tant Physician to the Hospital for Consumption and Diseases of the Whest, MrOMPtON, 6 g-rap0» Leigh Sin nf aPals eles clean ee sia alaiehep eae 465 On Protoplasmic Life. By F. Crace-Calvert, F.R.S. ...........+e002-- 468 Action of Heat on Protoplasmic Life. By F. Crace-Calvert, F.R.S....... 472 laistof Presents. 6... ce. de ees ee eee ob ees + oes oe 477 No. 129.—May 25, 1871. On the Temperature of the Interior of the Earth, as indicated by Observa- tions made during the Construction of the Great Tunnel through ¢he Alps. By D. T..Ansted, M.A., F.R.S., Kor See. GS. soem eee 481 Some Remarks on the Mechanism of Respiration. By F. Le Gros Clark, F.R.C.S., Professor of Anatomy and Surgery at the Royal College of Sur- PES OBIS gh i io) Pega t's ch oh pape) Chee ate. phaknn CMON waa ine RL eM Te se vate epiarees 486 Researches on the Hydrocarbons of the Series Cz, Han42—VII. By C. Schorlemmer ...... Yin dic apeiie atte gle ap whet Seen eee iy oc 487 Note on the Spectrum of Uranus and the Spectrum of Comet I., 1871. By William Huggins, LL.D., D.C.L., VP.RS. 22. ps0. 50s see 488 On a New Instrument for recording Minute Variations of Atmospheric Pressure. By Wildman Whitehouse, F.M.S. &. &¢....0..0.0+eeeee 491 June 8, 1871. Miection of Fellows’ 00.0... eee es aie a elas siele'e 0's «'« ae alee oer 494 June 15, 1871. On the Fossil Mammals of Australiaa—Part V. Genus Nototherium, Ow. fay. Prot. .F. Onven, PARIS. oor ooh Pee M6 lito ss 0 ohn nee 494 On Cyclides and Sphero-Quartics. By John Casey, LL.D., MR.LA. .... 495 On a Law in Chemical Dynamics. By John Hall Gladstone, Ph.D., F.R.S., qi. Allied: Tate pM att iesescte vies tows, 4.0 vps teiest winless ae ie ee 498 On the Organization of the Fossil Plants of the Coal-measures.—Part II. Lepidodendra and Sigillarie. By W. C. Williamson, F.R.S., Professor of Natural History in Owens College, Manchester 1X Page Contributions to the History of the Opium Alkaloids.—Part II. On he Action of Hydrobromic Acid on Codeia and its derivatives. By C.R. A. Wright, D.Se., Lecturer on Chemistry in St. Mary’s Hospital Medical fo) RSE on is SOD pe ORR a Te ee ne Pare ar a race ee 504 On the Measurement of the Chemical Intensity of Total Daylight made at Catania during the Total Eclipse of December 22, 1870. By Henry E. frentee, Bio), and T. i. Thorpé, PARSiBivis sos cccc chs igari sarees 511 On the Calculation of Euler’s Constant. By J. W. L. Glaisher, B.A., FR.A.S, 514 Records of the Magnetic Observations at the Kew Observatory. No. 1V.— Analysis of the principal Disturbances shown by the Horizontal and Ver- tical Force Magnetometers of the Kew Observatory from 1859 to 1864. By General Sir Edward Sabine, K.C.B., President .............. 000s 524 Amended Rule for working out Sumner’s Method of finding a Ship’s Place. Py eroatessor oir William Thonison, PSR. i .5 crore ccc eiees 524 On Linear Differential Equations—No. V. By W.H. L. Russell, F.R.S, 526 On the Undercurrent Theory of the Ocean, as propounded by recent ex- plorers, by Captain Spratt; C.5., RN. FOR.S. so cck ce ce eee 528 On the Physical Principles concerned in the passage of Blood-corpuscles through the Walls of the Vessels. By Richard Norris, M.D., Professor of Physiology, Queen’s College, Birmingham.................-eseeee 506 OEE OM ks Ras Flee Chk GH eNO LS VON Hae ce eG eo eee a o's 564 MMMM CCC Ol accesses ba gices syle M085 89 Cesicthigetesiass ». 573 Obituary Notices of Fellows deceased : James David Forbes ...........0. Wiig ek cc toe RR Sia eo Neca cae i yan selsia PUTING 2.66. oe ne eka SEs Cee eee 1x Purames Wlarke f:4.<8idasveilsseneei’ ch ORDERS Lace HES Peles xiii ametramne elem Mer ee ns kh eh pet £04 RAS Rab Ue BS) LS os xix PnmbaEPN PGETIgtS GLPRVES ce she fk eel hb as CERO as bide he tac XXVil ERRATA, Page 246, iine 4, for 200 lbs. read 2 volts. 2507" 2507 Page 287, line 27, for %¢ / readv=ne ?¢. 250R Page 288, line 29, for Q=C. pas 250R oe _ read Q=C [ ~ = os ins] o pio) jo) amt 1/2) SI o (| April t4th. 3....0.. Bad night ; stopped after 10 minutes, in consequence of XK Vale Apes stlys 2. /..0. Sky very clear. XVII. | January 16th...... XVIII. | September 20th ...| Occasional clouds. XIX. | February 16th ...| Sky hazy at sunset ; occasional clouds. [night. XX. | April 16th...:.....) Sky apparently not quite so clear as on the preceding XS pra zits, 6... XXII. | November 22nd...) Fog and white frost, afterwards drift. No remark about cloud. XVI. “On Linear Differential Equations.””—No. III. By W. H. L. Russert, F.R.S. Received June 11, 1870. The integrals obtained in my last paper on this subject were deduced by the same process which afforded the determinants in the first paper. It is obvious that these integrals could be found by a more direct investiga- tion. This is what I am now going to attempt. It will be found moreover that the present method will have the advantage of clearing away the am- biguities arising from the existence of common factors in the algebraical coefficient of the highest differential, and the denominator of the exponen- tial in the solution. It will also be found to lead us <9 certain ulterior results. Let us take the differential equation d°y F ; 19 d°y " " ee) dy (a+ Ba) 2Y +(e +6'o+ 72") SY + (a"+p'ety'e)W +(e" +B e+ y'"x)y=0.: Let us now put in this equation | y=E(ar jefe, We shall easily see that it is impossible for the exponential to contain 1870.] Mr. W. H. L. Russell on Linear Differential Equations. 15 higher powers of («) than here given. Then we shall have | eats adi da(u-+v2), = + (u-+ve)E : Al E+E oe ¢ faulutva), d° a° i ceil ve) i ‘ e [da(utve), L Substituting these values in the differential equation, and equating the co- efficients of the highest powers of (7) to zero, we have yB+ry =0, whence and also vrat3rup+2pry' +b +y'v=0; whence substituting for (7) and reducing, we have as before. The other integrals given in my last paper may be deduced in a cic way. This method suggested to me that it was possible to ascertain if any : aes linear differential equation admitted of a solution of the form y= Q where P, Q, p, q are rational and entire functions of (2). Let, as before, the ley equation be % | (a+ 0,2+... $m a) 6 (6, Bet) 6a Se 0, Oi Then it is easily seen that ae factors of g must be divisors of CO ate Conn tel ee) Weta bes hence if we have a, tavt...+ame”™=(ex—a)"(x—b).. we must have = Geet nett seb ty alt sosbes ee eet sie Now this series can evidently be written in the form y= R(a)etot met oe tm 0™, where R(x) can be expanded in descending powers of (#). Hence if this value of y be substituted in the proposed differential equation, we may de- termine 4,, 4,,.--+%, by the same process as before. 16 Mr. W. H.L. Russell on Linear Differential Equations. [June 16, To determine A,, A’—1,..., let : » Or c=at+ B &t—a 2 Then the solution of the resulting linear differential equation in (<) will be of the form —— y= — —R (z)erot Ai# af Aoz?+.. Ay 2". where R,(z) can be expanded in descending powers of (2), and therefore A,, A, A, ... be determined as aga In the same way, by putting c=06+ ~ we may determine B,. B,, In order to exhibit the accuracy of this reasoning, I will form some dif- ferential equations from given primitives, and then see if the above process -will enable us to reproduce these primitives as solutions. Let us take the primitive 1 y= (a+ 1)e2?+32+ 51: From this we may deduce the differential equation avy P dy (a? —a?—x#+ 1) — — (a* + 20° —62?—3a4 4). — (2a° + a* + 4a°—a?—5a—4)y=0. Let y= Ri pef eri, If we use higher powers of (#) in the exponential, they will not give us a result. y- @Y = > am given in the earlier part of this paper, and equating the highest terms to zero, we have Substituting in the differential equation the values of W y?—y—2=0 and 2uy—r?—p—2v—1=0, whence y=2 and p= 3, or v=—1, and p=0, and therefore 2 S dx(u+ va)=2°+32, or —— The divisors of the first term are r—1 and +1. Let « = z +1, and the differential equation becomes Z “ a*Y (0,7 dy 6 = pize se) ra (22 tot) +(32°+...)y=0, 1 which gives a solution of the form y=R,(z)e*, when z= Do te If we put r= : —1, the differential equation will be of the form (Azt+...) S44 (B14... B+ (Ceo+.. yee 1870.] Mr. W. H. L. Russell on Linear Differential Equations. 17 in which the numerical coefficients are of no consequence, as the equation does manifestly not admit of an exponential solution. If, then, the differ- ential equation admits of a solution in the proposed form, it must be one of the two forms, : y=R(a)e z= or y= R(w)e z wes where R(«) is a rational and entire function of (x) or a canst fraction. Using the first form, we should of course determine it equal to v+1. 22+ 34¢+ —— 1 Asa second example, we form from the primitive, y= («#— l)e"* e+1, the equation (@—1)(e+1)° 2 (2a? +a— 3) 2 (a + 5a" 44+ 1)y= 0. Here we must put me, ude, higher powers of (a) in the exponential ] leading to no result. Substituting, we find p=+1. Let c= Pais and. the differential ee becomes (28+...) 4 (att. JE tet... =O, which gives y=R(z)e*. If we put = z we find no exponential solution. cA Consequently the solution of the equation, if it can be obtained under the form we are now considering, must be one of the two expressions, 1 1 y=R(a)e ei and y=R(w)e "eH, As a third example, I take the primitive, 1 y=xe av and from it the differential equation d’y dy im ie ed 2 rh Sle A 2 pein = (5 wv a? + (2a* + 2) - (a + 4a’? + 2u—2)y=0 We must evidently here put y=R(z)e/##, which gives p=+1. If 1 : o the equation becomes z = 22 oU_ t4e 422" —22°)\y=0. If we put here y=R(z\e/@+»), employ the formule given in the first part of the paper, and equate the coefficients of the highest powers of (2) to zero, we have v?—2y=0, 2uv—2u=0, whence v=2, and p=0; and 1 1 y must be one of the two forms R(x)e"+#, or R(v)e** ®. VOL, XIX. Cc i Mr. A. Le Sueur on Observations with the | {June 16, XVII. “ Observations with the Great Melbourne Telescope, in a Letter to Prof. Stokes.” By A. Le Suzur. Communicated by Prof. Sroxss, Sec. R.S. Received April 18, 1870. Observatory, Feb. 27. Dear Sir,—I have little more definite to tell you with reference to the star 7 Argis; thinking that a larger dispersion would be of advantage, 1 have had a supplementary arrangement added to the spectroscope, by means of which a direct prism may be interposed between the collimator and the usual prism. With this increased dispersion, the red line keeps its place ; the yellow one turns out to be slightly more refrangible than D. The green lines, which, with the smaller dispersion, were very difficult, now become almost unmanageable ; this would seem to throw some doubt on their reality, as mere extra dispersion should have little effect on real lines. The direct prism being a small one, does not take in the whole of the | pencil when condensed to the limits bearable by the collimator; but as the arrangements at my disposal do not in any case admit of utilizing the full condensation, the smallness of the prism has not had any material effect. On the whole, I am now inclined to think that, with respect to the green lines, the appearance of the spectra is due to a character of light somewhat similar to that of a Orionis, &c. ; a spectrum of groups of dark lines, with spaces more or less free between them, producing the effect (when the light is not sufficient to bear a slit fine enough for dark lines) of a spectrum crossed by bright lines. The behaviour of the red line, however (of the blue one, being less con- spicuous, I cannot speak with so much confidence), would lead to the already drawn inference that it is a real hydrogen line. I have examined other stars of about the same magnitude as » Argis ; in the majority of these there is not even a suspicion of condensation in any part of the spectrum ; red stars, R Leporis for instance, give a spectrum not dissimilar to that of » Argtis; but the red line on none of the stars examined is so-conspicuous as in 7. The weather since the beginning of this year has been more favourable, so that Iam able, by degrees, to increase the amount of work done. The routine work is the review of figured nebule ; as might be expected, the 4 feet gives views considerably different from the C. G. H. drawings ; but at present I have nothing worthy of special mention. The light of the nebule, as they are taken up for general examination, is analyzed with the prism; of those which have been examined I have yet found none for which it may be certainly said that the light is not of defi- nite refrangibilities. In irregular nebule, the bright knots even, which are so distinetly call -1870.] Great Melbourne Telescope. 19 mottled as to point to a cluster condition, give out, as far as I have yet seen, light which is monochromatic, or nearly so. _ Acknowledged clusters, where discrete stars are plainly discernible, are of course excluded; of the nebulosity mixed up with such clusters as 47 Toucan, I cannot speak with certainty ; but if the light were monochro- matic, I think that (in the case particularized at least) the brilliancy would be sufficient to afford a definite impression. Would you call Lord Rosse’s attention to 1477-78 (general catalogue), of which I enclose a diagram from measured positions? The configura- tion differs so widely from that given in the Philosophical Transactions, ° that, with reference to the rotation of the two nebulous stars, it would ; be interesting to have the evidence of any additional observations made at Parsonstown. ¥ _ From Mr. Huggins’s observations of the nebule in Orion, I gather that he has seen only the three usual lines; with a wide slit, I had lately | C a very strong suspicion of a fourth line, probably G. I have not spe- cially examined the nebulee since ; but probably Mr. Huggins will be able to give confirmatory evidence. On the night of February Ist we had a pretty brilliant auroral display ; being at work at the time, I missed part of it; but as soon as I became aware of its existence I applied the spectroscope. At moments four lines already known were easily visible, the chief line being remarkably brilliant. A much narrower slit than that used could have been borne at the time of maximum display, which, however, lasted only a few moments. I was intent on measuring the lines, as at the time I had no published definite IN ® Ss information with reference to other than Angstrém’s special line; but at moments light was seen at the red end of the spectrum sufficiently bright to leave a distinct impression of colour; when, however, special attention was devoted to that part of the spectrum the aurora had greatly diminished in brilliancy, so that I was unable to make out whether a red line existed, or whether there was a general spectrum at the red end. I incline to the latter opinion, and put it down to the rose-coloured are; this arc, however, which seemed pretty brilliant after the streamers had disappedted! did not then give a visible spectrum. Probably this phenomenon has been ob- served before to better purpose; but I cannot find mention thereof in published accounts. Yours truly, A, Lz Sueur. c 2 20 Mz,OGcenlenintronwie ON [June 16, XVIII. “Chemical and Physiological Experiments on living Cin- chone.”’ By J. Brovaguton, B.Sec., F.C.S., Chemist to the Cinchona-Plantations of the Madras Government. Communi- cated by Dr. Epwarp Franxuanp. Received May 16, 1870. ‘ (Abstract.) The memoir describes the principal scientific results which have been obtained during the last three years, in the course of chemical work on the Neilgherry Cinchona-plantations. The chemical characteristics of the various parts of the Cinchona plant are described. The condition in which the alkaloids are met with in the living bark is shown to be that of a slightly soluble tannate existing in the parenchymatous cells. The order of formation of the alkaloids is shown to he, Ist, silent lizable quinine ; 2nd, crystallizable quinine; 3rd, cinchonidine and cincho- nine. Reasons are adduced for thinking that the alkaloids are really formed in the tissues in which they are found. The effect of the solar rays falling on the bark, either while living on the tree or when separated, is shown to be prejudicial to its contained alkaloids. The effects of shielding the bark artificially, and the influence of elevation of the site of growth, are detailed. The question as to whether the alkaloids are substitutes for the nite bases is discussed, and a series of experiments is described, which combine to show either that such substitution does not take ve or does so Ba in a very partial degree. XIX. “ Researches on the Hydrocarbons of the Series C,H,, ,2?—VI. By C.Scuorzemmer. Communicated by Prof. Stoxss, Sec.R.S. Received June 14, 1870. In my last communication* I stated that, from the results of my ex- periments, I came to the conclusion that, by acting on these hydrocarbons with chlorine, a mixture of primary and secondary chlorides was formed, as the alcohols derived from these chlorides yielded on oxidation, besides an acid containing the same number of carbon atoms as the alcohol, also acetones, or the characteristic oxidation products of secondary alcohols. The correctness of this conclusion has been fully proved by further ex- periments, and I am at present engaged in investigating the conditions under which the one or the other of these chlorides is formed. In order to obtain decisive results, it was first of all required to work on considerable quantities of a hydrocarbon; and I selected for this research hexyl-hydride, C,W,,, from petroleum, as this body can be obtained the most easily in a sufficient quantity. The derivatives of hexyl-hydride have been fully investigated by Cahours * Proc. Roy. Soc. vol, xviii. p. 25, sant men SSE he " 1870.] | Hydrocarbons of the Series C,H, 5 21 and Pelouze*, but the results which I have so far obtained differ in several important points from those of these eminent chemists. By acting on this hydrocarbon with chlorine in the cold and in presence of iodine, I prepared hexyl-chloride, C, H,, Cl, already described by Cahours and Pelouze, which boils at 125°-126° C.; but besides this compound there was also formed a pretty large quantity of a product which distilled between 126° and 135° C., and from which no substance having a constant boiling-point could be isolated. This higher boiling portion can be sepa- rated only with difficulty from the chloride boiling at 125°-126°, for even after repeated distillations a residue of the former is always left behind. On heating the lower boiling chloride with glacial acetic acid and potassium acetate a hexyl-acetate was obtained, of which the larger portion distilled between 158° and 162°, the boiling-point rising up at last to 170°. Besides the acetate a pretty large quantity of herylene, C,H,,, had also been formed by the decomposition of the chloride. The chloride boiling between 126° and 135°, treated in the same way, yielded also hexylene, besides a hexyl-acetate distilling between 160° and 170°. According to Cahours and Pelouze, this ether boils at 145°. I did not try to isolate definite compounds from these acetates, as I found that by converting them into the alcohols and subjecting these to frac- tional distillation, they easily split up into two distinct compounds,—one, which forms the greater part of the mixture, boiling constantly at 140°- 141°, and the other and smaller portion distilling between 150° and 155°; the quantity of liquid coming over between these two limits being quite insignificant. The liquid boiling at 140° is a secondary hexyl-alcohol; on oxidation it yields first an acetone, which, by further oxidation, splits up into acetic acid and butyric acid. It is therefore methyl-butylearbinol,— Ci (ut } CH. OH. Whether this compound is identical or not with the secondary hexyl-alcohol, which Erlenmeyer and Wanklyn obtained from mannite, I am not yet able to decide. The body which distilled between 150° and 155° is a primary heryl- alcohol, C,H,,OH ; on oxidizing it an oily acid was formed, which, as the analysis of its silver-salt showed, has the composition of caproic acid, C, H,,0,. Cahours and Pelouze mention in their memoir only the latter alcohol; they do not state, however, under what NEG they acted upon the hydride with chlorine. I have found that, by treating this hydrocarbon with chlorine alone in the cold as well as at the boiling-point, chlorides are obtained which boil between 125° and 135°, and which appear to be identical with those described above. I intend not only to study these chlorides more fully, but also to * Annal, Chim. Phys. (4) 1.9. 22 Dr. C. B. Radcliffe on Animal Electricity. [June 16, compare the alcohols obtained from them with the secondary alcohol from mannite and from hexylene, and with the primary hexyl-alcohol which is found in fusel-oil. XX. “ Formation of Cetyl-alcohol by a singular reaction.” By C. SCHORLEMMER. Communicated by Prof. Sroxrs, Sec. B.S. Received June 14, 1870. | On heating a mixture of sebacic acid, C,, H,,0,, and caustic baryta, be- sides the hydrocarbon C, H,,, which I have described in a former commu- nication*, other products are formed, amongst which there is a solid body, which, by several crystallizations from alcohol, was obtained in small white crystals. On analyzing it, Mr. Dearden obtained results which led to the formula C,, H,,O, which is that of cetyl-alcohol :— Calculated. Found. Te ae Te ae aes Wei as 192 79°34 79°3 78:9 H,, eh See 34 14°05 13°8 13°9 O 16 6°61 a peeve 242 100-00 This body has not only the composition but also the characteristic pro- perties of cetyl-alcohol; it melts at 49°, and solidifies again at the same temperature. - The formation ef this compound is certamly very singular, and perhaps the more so as cetyl-alcohol is so easily oxidized to sebacic acid by the action of nitric acid. I intend to obtain larger quantities of it by the above reaction and to investigate it. XXJ. “Researches in Animal Electricity.’ By C. B. Rapcuirrs, M.D. Communicated by Cuartes Brooks, M.A. Received May 19, 1870. (Abstract.) Part I. The subjects of the present inquiry are three in number :—1. The elec- trical phenomena belonging to living nerve and muscle during rest; 2. The electrical phenomena which mark the passing of nerve and muscle from the state of rest into that of action; and 3. The workings of voltaic electricity, and of electricity generally, upon nerve and muscle. 1. The electrical phenomena belonging to living nerve and muscle during the state of rest. Argument,—Living nerve and muscle have an electricity of their own, which fails by degrees as life dies out, and is wanting altogether after * Proc. Roy. Soc. vol. xvi. p. 376. 1870.] ~—Dr.C. B, Radeliffe on Animal Electricity. 23 death. This electricity is made known by the electrometer, as’ well as by the galvanometer. Living nerve and muscle supply to the galvanometer currents, called respectively the nerve-current and the muscle-current, when the sides of the fibres are connected, through the coil, with either one of the two ends, or when certain points upon the sides or upon the ends are brought together in the same manner, the direction of these cur- rents showing that the sides of the fibres are positive in relation to either of the two ends, or else the reverse (the instances of reversal being the exception and not the rule), and that the positive surface becomes more positive, and the negative surface more negative, as the distance from the line of junction between these surfaces increases. Living nerve and muscle are also (as is now for the first time distinctly proved by means of Thom- ‘son’s New Quadrant Electrometer) capable of acting upon the electro- meter, the action showing that the electrical differences upon which the nerve-current and muscle-current depend are not the same in all parts of the fibres, the differences between the sides and the ends being differences in kind, like those which belong to the two surfaces of a charged Leyden jar, the differences upon the sides singly, and upon the ends singly, being only those which indicate different degrees of tension in one kind of elec- tricity. In accounting for these phenomena, the very imperfect conducti- bility of nerve and muscle, and of animal tissue generally, is taken as a starting-point. It is assumed (and in support of this assumption some new measurements of the resistance of nerve and muscle to electrical con- duction are given) that in nerve and muscle the sheaths of the fibres may conduct electricity so imperfectly as to be capable of acting as dielectrics,— that a charge of one kind of electricity, developed on their outsides (by oxygenation’or in some other way), may induce an opposite charge on their insides,—and that the electrical condition of the two ends of the fibres may be opposed to that of the sides, because the charge induced within the sheath is conducted to the ends by the contents of the sheath, It is sup- posed, in short, that the fibres of living nerve and muscle during rest are so many charged Leyden jars, their electrical condition at this time being statical, not, current, and that the nerve-current and muscle-current are no more than accidental phenomena arising from the: galvanometer being placed between two points which happen to be electrically dissimilar. And in support of this view it is pointed out that precisely parallel electrical phenomena may be obtained from a piece of wood, shaped like the piece of nerve or muscle, and coated on its sides, but not at its two ends, by a sheath formed of two layers of tinfoil separated by an intermediate layer of thin gutta-percha sheeting, if only the sides be charged as the sides of the piece of nerve or muscle are supposed to be charged, and if the electrodes of _the galvanomer or electrometer be applied in the proper manner. 2. The electrical phenomena which mark the passing of nerve and muscle Srom the state of rest into that of action. Argument.—The nerve-current and muscle-current disappear almost 24 Dr. C. B. Radcliffe on Animal Electricity. {June 16, entirely when nerve and muscle pass from the state of rest into that of action. The ‘‘secondary contraction” set up in a muscle by simply laying its nerve upon another muscle or nerve in which a state of action is present, points to a disturbance outside the acting nerve and muscle such as might be caused by a discharge of electricity, and suggests the idea that the sudden disappearance of nerve-current and muscle-current in action may be owing to such discharge ; and this view is not a little borne out by certain close anatomical and physiological analogies which are found to exist between the muscular apparatus and the electric organs of the Tor- pedo. In short, the evidence seems to show that a discharge analogous to that of the Torpedo is developed, as Matteucci supposed, when nerve and muscle pass from the state of rest into that of action, and that the dis- charge of the Torpedo itself may be nothing more than the unmasked manifestation of a discharge which occurs in a masked form in every case of nervous and muscular action. 3. The workings of voltaic electricity, and of electricity generally, upon nerve and muscle. 7 Argument.—The behaviour of muscle under the action of the so-called ‘inverse’ and “direct” currents is taken as the text in the present inquiry. Contraction in this case plainly belongs, not to the time when the circuit remains closed, but to the moments ‘of closing and opening the circuit, when the nerves and muscles are acted upon by instantaneous currents, called ewtra-currents, which currents are in very deed discharges. These extra-currents agree with ordinary induced currents in their discharge-like character; but they disagree in their direction, the extra-current at the closing of the circuit taking the same course as the constant current, the extra-current at the opening having the opposite course ; and this point of difference is not to be lost sight of. At first both extra-currents cause contraction ; afterwards, when the muscle and nerve have lost some of their susceptibility to impressions, only that extra-current causes contraction which happens to pass in the same direction as that in which motor im- pulses are transmitted along the motor nerves to the muscles. With this clue, indeed, it is not difficult to trace to its cause every variation in the order of contraction which characterizes the case in question. Nor is it altogether unintelligible that the behaviour of the muscles as to the continuance of these contractions should, under ordinary circumstances, differ in the case where the current is inverse, and in the case where the current is direct.-. This difference is noticed when the voltaic circuit is in- sulated, but not when an earth-wire is put to either of the poles. With the voltaic circuit insulated, the contractions continue for 60! or longer in the case where the current is inverse, and for no longer than 15! or 20! in the case where the current is direct: with the earth-wire at the negative pole the contractions continue for 60! or longer in the case where the current is inverse, and in that in which the current is direct also; with the earth- b oil a . 1870.) —- Dr. C. B. Radcliffe on Animal Electricity. 95 wire at the positive pole the contractions continue no longer than 15! or 20! in the case where the current is direct, and in that in which the cur- rent is inverse also. With the earth-wire at either pole—that is to say, the part acted upon by the inverse current and the part acted upon by the direct current are both made to contract for the same length of time, the contraction in both parts being 60’ or longer if the wire be at the negative pole, and for no longer than 15! or 20! if it be at the positive pole. Now the earth-wire changes the charge of free electricity associated with the inverse and direct currents, but it does not alter the course of those cur- rents. When the voltaic circuit is insulated, the part acted upon by the inverse current is charged positively, and that acted upon by direct current negatively, the charge in each case proceeding from the voltaic pole which happens to be nearest ; when the earth-wire is put to either pole, the free electricity of that particular pole runs off to earth, and the parts between the poles (the half traversed by the inverse current and the half traversed by the direct current alike) are charged with the free electricity of the other. pole,—with positive electricity if the wire be at the negative pole, with negative electricity if it be at the positive pole. The whole case, indeed, is one which seems to admit of only one conclusion, namely this— that the longer or shorter continuance of the contraction must have its ex- planation, not in the current being inverse in the one case and direct in the other, but in the free electricity associated with one or both these currents being positive in the one case and negative in the other, the contraction continuing for the longer time when this electricity is positive, and for the shorter time when it is negative. And that this should be so is not alto- gether unintelligible if the natural electrical condition of the fibres of living nerve and muscle be what it has been assumed to be—a condition in which the outsides and insides of the sheaths are in opposite electrical states, the charge on the outside, usually positive, inducing the opposite charge on the inside; for on this assumption it may well be that a positive artificial charge to the outsides of the sheaths may preserve the natural activity of the fibres, and so favour the continuance of the contraction by keeping up their natural charge, the positive electricity outside the sheaths inducing negative electricity inside the sheaths ; and that a negative artificial charge may have the contrary effect, the negative charge outside the sheaths in- ducing positive electricity within the sheaths, and so producing that re- versal in the relative position of the two electricities which is only met with when the fibres are upon the point of losing their activity. Voltaic electricity, therefore, would seem to act upon nerve and muscle, not by the constant current which passes while the circuit is closed, but by the charge of free electricity, positive or negative, associated with this current, and by the extra-currents which pass at the moments of closing and opening the circuit, which extra-currents are in very deed discharges, the charge being favourable to the continuance of activity when positive, and unfavourable when negative, the instantaneous currents or discharges 26. Dr. C. B. Radcliffe on Animal Electricity. [June 16, causing action. As with the natural electricity of nerve and muscle, so in this case, rest and charge, and action and discharge would seem to go together. And so also with the action of Franklinic and Faradaic electricity upon nerve and muscle. With Franklinic electricity the state of rest in both nerve and muscle is plainly connected with the charge, and the state of action with the discharge. With Franklinic electricity, too, the positive charge is found to be favourable to the continuance of the state of action, and the negative charge unfavourable. And so likewise with Faradaic electricity, not only as regards the connexion of the state of action with the discharge, for the induced currents may be resolved into discharges, but also as regards the connexion of the state of rest with the charge, for in the interval be- tween the two induced currents the secondary circuit is in fact occupied by a charge of electricity. Part II.—On Electrotonus. Argument.—There is reason to believe that the whole truth has not yet been elicited respecting the movements of the needle of the galvanometer and the modifications of the activity of the nerve which are characteristic of electrotonus. The movements of the needle of the galvanometer characterizing electro- tonus appear to be due, not, as is commonly supposed, to modifications of the nerve-current consequent upon the action of the voltaic current, but to the passage through the coil of the galvanometer of streams of free electri- city, positive or negative, as the case may be, from the voltaic pole which happens to be nearest to the coil,—of free positive electricity from the positive pole in anelectrotonus, of free negative electricity from the negative pole in cathelectrotonus. They cannot, so it is argued, be due to modifica- tions of the nerve-current consequent upon the action of the voltaic current, because the same movements continue when there is no nerve-current to be thus modified, as when a dead nerve is used in place of a living nerve, _ or even when other bodies are substituted for nerve; they may, so it is suggested, be due to streams of free electricity passing through the coil of the galvanometer from the nearest voltaic pole, because such streams do pass in this direction, and because streams of free electricity from a frictional machine so passed give rise to similar movements,—the stream of positive electricity to the movement of anelectrotonus, the stream of negative electricity to that of cathelectrotonus. This is the view taken of the movements of the needle of the galvanometer characterizing electro- tonus. | A different conclusion to that commonly held is also thought to be necessary respecting the modifications of the activity of the nerve in elec- trotonus. Instead of this activity being suspended in anelectrotonus and exalted in cathelectrotonus, the facts, many of them new, are, when fully realized, found to show that this suspension is met with, not in anelectro- 1870. ] Dr, C. B. Radcliffe on Animal Electricity. 27 tonus only, but in cathelectrotonus also. It would seem, indeed, that the only difference between anelectrotonns and cathelectrotonus in this respect is, that this suspension is a little less complete in cathelectrotonus than in anelectrotonus, a lesser ‘‘ stimulus” serving to cause action in the former state than in the latter. It would even seem that any proper exaltation of activity is to be met with in anelectrotonus rather than in cathelectrotonus. Such are the conclusions respecting the modifications of the activity of the nerve in electrotonus which are believed to be warranted by all the facts, old and new alike. Nor is tke increase of contraction detected by the myograph in cath- electrotonus a sufficient reason for concluding that the irritability of the nerve and muscle is exalted in this state; on the contrary, this increase may be nothing more than the natural consequence of the altered electrical condition in cathelectrotonus. In ordinary muscular action, the state of elongation or relaxation is believed to be caused by the mutual attraction of the charges of opposite electricities disposed upon the two surfaces of the sheaths of the muscular fibres, this attraction compressing the sheaths at right angles to their surfaces; in ordinary muscular action the state of contraction is believed to be brought about by the discharge of the charges which caused the opposite state of elongation, this discharge leaving the fibres free to obey, as simple elastic bodies, the attractive force inherent in the physical constitution of their molecules. In cathelectrotonic muscular action, on the other hand, it is believed that the state of elongation may be greater than that which is natural to the fibres (after removal from the body, at least), because the charge communicated from the negative pole to the fibres is greater than the natural charge of the fibres, the artificial charge to the outside of the sheaths inducing an equivalent charge of the opposite electricity on the insides, and so causing increased elongation by increasing the compression to which the sheaths are subjected between these two charges; and that the contraction may be increased, because contraction, according to this view, is only the return of the fibres, by virtue of their elasticity, from the previous state of increased elongation. “The case supposed is precisely that which may be imitated in every particular upon a narrow band of thin india-rubber sheeting, coated with gold-leaf on its two surfaces within a short distance of their edge, or else wetted to the same extent simply with water, and by charging and dis- charging in turn; for as the charge is communicated the band goes on elongating until the charge has reached its maximum, and when discharge is brought about there is sudden shortening, the degree of shortening being always commensurate with the previous degree of elongation. What happens is that which is supposed to happen in ordinary muscular action and in cath- electrotonic muscular action also, if only the effects of the smaller charge and discharge be made to stand for the first, and those of the fuller charge and discharge for the last form of muscular action. It is of no moment, also, whether the electricity used in charging be negative or positive. Whether - 28 Dr. C. B. Radcliffe on Animal Electricity. [June 16, the charge be negative or positive, the results are the same, and therefore it is plain that there ought also to be increased contracticn in anelectrotonus if this be the true explanation of the increased contraction which happens in cathelectrotonus. In cathelectrotonus it is assumed that the negative charge from the negative voltaic pole charges the outsides of the sheaths of the fibres negatively, and induces an equivalent charge of positive electricity on the in- sides ; in anelectrotonus, on the other hand, itis assumed that the positive charge from the positive voltaic pole brings about a contrary state of things in the fibres, charging the outsides of the sheaths positively, and affecting the insides negatively by induction. The difference assumed to exist between the two electrotonic states is in the relative position of the two charges upon the sheaths of the fibres, nothing else. It is not a difference which can affect the elongation of the fibre if elongation be brought about by the mutual attraction of the opposite charges with which the sheaths are charged; for the attraction of either charge for the other must be the same, whether it be exercised from within the sheath or from without it. It follows, indeed, from what is supposed, not only that there should be in- creased contraction in anelectrotonus as well as in cathelectrotonus, but also that the state of rest in both electrotonic conditions should be characterized by increased elongation. And what there should be in theory there is in fact ; for it proves on inquiry that contraction may be caused in anelectrotonus by an adequate “stimulus,” that this contraction is greater than that caused hy the same “stimulus”’ in the unelectrotonized state, and that actual increased elongation of the fibres is an effect of both cathelectrotonus and anelectrotonus. The view of muscular action here taken is that which has been always advocated by the author as regards contraction, but it is modified somewhat as regards elongation; for now, instead of looking upon elongation as arising from the mutual repulsion among the muscular molecules set up by the presence in the muscle of a single charge of electricity, this state is referred to the mutual attraction of opposite electrical charges disposed, as in a Leyden jar, upon the two sur- faces of the sheaths of the muscular fibres. Looking back, then, at the history of electrotonus there appears to be nothing contradictory to what has been already said respecting the work- ings of electricity upon nerve and muscle. It is still the same story of rest along with the state of charge, and of action along with the state of discharge, with this significant addition, that in electrotonus the charge is shown, not only as coincident with the state of rest, but as having an actual power of suspending action in both nerve and muscle, and of causing increased elongation of the fibres in muscle. 1870.] Presents. 29 Presents received June 16, 1870. Transactions. Albany :—Albany Institute. Transactions. Vols. I., III. 8vo. Albany 1830-55. The Institute. Homeopathic Medical Society of the State of New York. Transactions. 8yo. Albany 1863. The Society. Society for the Promotion of Agriculture, Arts, and Manufactures. Transactions. Vol. I. 8vo. Albany 1801. The Albany Institute. Society for the Promotion of Useful Arts. Transactions. 8yvo. Albany 1807. The Albany Institute. Berlin :—Kon. Preuss. Akademie der Wissenschaften. Monatsbericht, Jan,, Feb., Marz 1870. 8vo. Berlin 1870. The Academy. Birmingham :—FEighth Annual Report of the Free Libraries’ Com- mittee. 8vo. Birmingham 1869. The Borough. Bordeaux :—Académie Impériale des Sciences, Belles-Lettres et Arts. Actes. 3° série, 30° année, 4™* trimestre ; 31 année, 1* trimestre. 8vo. Bordeaux 1868-69. Prix décernés pour l’année 1869. 8vo. Bordeaux 1870. The Academy. Société Médico-Chirurgicale des Hépitaux et Hospices. Mémoires et Bulletins. Tome LY. fasc.1, 2. 8vo. Bordeauwv 1869. The Society. Brussels :—Académie Royale de Médecine. Mémoires Couronnés et autres Mémoires. Collection in 8vo. Tome I. fasc. 1. 8vo. Brua- elles 1870. Bulletin. 3°série. Tome III. Nos. 11,12; Tome IV. Nos. 1-4. 8vo. Bruxelles 1869-70. The Academy. Académie Royale de Belgique. Bulletin. 2° série. Tome XXIX. Nos. 4,5. 8vo. Bruwelles 1870. The Academy. Observatoire Royal. Annales Meétéorologiques, 3° année, ff. 5-12; 4° année, ff. 1-3. 4to. Bruwelles 1869-70. The Observatory. Calcutta :—Asiatic Society of Bengal. Journal. 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The Society adjourned over the Long Vacation to Thursday, Novem- er 7. “On Appreach caused by Vibration”? By FReprrick GuTHRIE, B.A. Communicated by Prof. G. G. Sroxes, Sec. B.S. Re- ceived August 26, 1869*. § 1. The chain of experiments which I have to describe arose from the endeavour to explain an observation that a delicately suspended piece of cardboard moves, from a considerable distance, towards a vibrating tuning- fork. It will be preferable to detail the experiments, not in the order in which they occurred to me and were actually performed, but in the order in which I conceive them to form a logical sequence. § 2. The experiment of Clement shows that when a continuously renewed current of air passes between two parallel disks from the common axis to- wards the circumference, the disks are urged together. Consequently, in seeking to explain the fact observed in § 1, it was necessary to examine the air surrounding the resonant fork in order to ascertain whether air-currents existed in its neighbourhood ; and further, to distinguish between such currents as might be found to move in closed curves forming whirlwinds in the immediate neighbourhood of the fork, and such as might radiate in un- closed paths from the fork through the air. §3. In 1831 Mr. Faraday +, in tracing the cause of the accumulation of light particles on the internodal points and lines of vibrating bodies, came to the conclusion that such accumulation was due to minute whirlwinds, and not, as had been held by M. Savart +}, to the existence of secondary nodes. A general conclusion at which Mr. Faraday arrived was this: whenever the different parts of a surface are vibrated to different degrees, there is always a tendency for the air to flow along the surface of the vibrating body to- wards the more violently agitated portions from the less agitated. § 4. It is clear that, before examining the possible connexion between these superficial whirlwinds and. the fact mentioned in § 1, it is necessary to examine into the existence of air-currents of unclosed paths. * Read Dec. 17, 1868. See abstract, vol. xvii. p. 106. t Phil, Trans. 1831, p. 299. { Ann. de Chim, et de Phys. t, xxxvi. pp. 187, 257. : p 2 36 Mr, F. Guthrie on Approach caused by Vibration. The tuning-fork which was most employed, and Fig. 1. which I call fork A, gave 128 complete vibrations per y second, and had the following dimensions :— x x meétre. 0 y=0°0230, o x=0°0172, 0 2=20°3255. ; Lath I call the three faces intersecting in 0, the faces a, 6, ah and ¢ respectively. Let the symbol H,, &¢. denote the position of the fork when the face c is horizontal, &e. §5. Experiment 1.—The fork A was set vibrating by drawing the bow across the edge oy; the plane of vibration was accordingly parallel to 6. The fork was then brought into the neighbourhood of an ascending thread of smoke. The fork and smoke had in succession the three relative post- tions :— (1) H,. The smoke passed across the face a parallel to oy. (2) H,: The smoke passed across the face 6 parallel to oz. (3) H,. The smoke passed across the face c parallel to oz. In ali cases the smoke clung to the surface across which it passed as though the fork were at rest. § 6. Lxperiment 2.— A cylindrical glass tube T, 0:4 m. long and 0-042 m. in internal diameter, was fastened (fig. 2) —==U1______] in a horizontal position. One end was left open, the other carried a cork, through the centre of which passed a horizontal | tube ¢, 0°04 m. long and 0-:0035 m. in- ternal diameter. These tubes were filled with smoke, and the fork A, which had been set vibrating as in §5, was brought —==J_______}] ] 4 to the open end of the wide tube. he fork and tube had in succession the four relative positions shown in fig. 2, namely :— (1) H,. Axis of tube perpendicular to a. (2) H,. Axis of tube perpendicular OO ar eee “ to 0. (3) H, or H,. Axis of tube perpendicular to ec. (4) The same as (3), but having one prong of the fork thrust as far as possible into the tube T. In none of the cases did the smoke show any tendency to escape through the tube ¢, nor was fresh air drawn in. § 7. Experiment 3.—The cork and tube ¢ of experiment 2 were with- Mr, F. Guthrie on Approach caused by Vibration. 37 drawn and replaced by a film-bubble of glycerine-soap-water. The com- binations of position of experiment 2 were repeated. In none of the cases did the bubble show any variation from the vertical plane. §8. Hence I conclude that when a tuning-fork is in a state of plane vibration, 10 permanent true air-currents are formed; that is, no air- currents could be detected departing from any side of the fork and pe- netrating the surrounding air in unclosed paths. § 9. The superficial whirlwinds examined by Mr. Faraday may be sup- posed to be greatly modified when they are excited in the immediate neighbourhood of a solid body; and as the “attraction”? which formed the starting-point of the present examination (§ 1) is exerted upon a solid body in the neighbourhood of the resonant fork, some experiments, sup- plementary to those of Mr. Faraday, were found necessary. § 10. Numerous experiments, which need not be here detailed, showed (1) that Mr. Faraday’s surface-currents, as exhibited on a freely vibrating fork, are very much modified when the fork vibrates in the immediate neighbourhood of a rigid plane, and (2) that the effects of any currents produced by vibration do not extend sensibly beyond 0:006 m. from the fork’s face, and only even to this extent near the a face. § 11. We shall see that the existence of such air-circuits, confined as they are to the immediate vicinity of the fork, are quite insufficient to ac- count for the class of phenomena which have to be described, and which are similar to the fundamental fact mentioned in § 1. § 12. Experiment 4.—To one end of a splinter of wood, 0°5 m. long, a card 0:08 m. square was fastened in such a way that the plane of the card was vertical, and contained the line of the splinter. The whole was hung from a fibre of un- leak spun silk (fig. 3) and counterpoised. The Ca Shae ered tuning-fork A was set in vibration as be- fore, and was brought towards thecard in the three relative positions cer- responding to those of § 6, namely :— (1) (H1,). The face a parallel to the card. (2) (H,). The face 6 parallel to the card. (3) (H, or H,). The face ¢ parallel to the card. In all three cases the card moved towards the fork. The rate at which the card moved was greatest when the fork was sounding loudest. In all three cases it was possible to draw the card from a distance of 0:05 m. at least,—a distance quite beyond the direct influence of the superficial whirls which exist in position (1) (on face a). § 13. There is perhaps nothing essentially contrary to reason in the con- ception of two bodies in space free to move, so related to one another that while the first has no tendency to move towards the second, the second has a tendency to move towards the first, But if the tendency of the one Fig. 3. a — a a aa a aaa ea aa ace 38 Mr. F. Guthrie on Approach caused by Vibration. to move be caused by the condition of the medium between the two, it seems inevitable that the tendency shall be mutual. Thus, if that tendency result from a general diminution in the tension of an elastic medium be- tween the two, they will be urged towards one another. To test the reci- procity of the motive tendency in the case under consideration the follow- ing experiment was tried. § 14. Experiment 5.—The tuning-fork A was fastened to the end of a rod 1:0 m. long; the other end of the red was counterpoised, and the whole was hung from a silk tape. If the vertical plane passing through the rod be called V, then the rod and fork received in succession the rela- tive positions,— (1) (H,). V parallel to a. (2) (H,). V parallel to 6. (3) (H, or H,). V parallel to e. In (1) and (2) the fork was simply hung from the suspended rod; in (3) it was fastened to an iron rod in the direction of its axis, and the two were then attached to the suspended rod at their common centre of gravity. The fork was sounded by the bow as before, and a piece of card 0°05 m. square was brought near the face a (in 1), 6 (in 2), ande (in 3). Im all eases the suspended fork approached the card; but, owing to the great inertia of the suspended fork and counterpoise, the motion was much slower and less striking than was the case when the card was hung. § 15. Experiment 6.—Further, instead of a card, a second fork, B (sounding A), was set in vibration, and brought into the neighbourhood of the vibrating suspended fork A. The three faces a’, 6’, c' of the fork B were held in succession parallel to the three faces a, 6, c of the fork A, that is parallel to V when the faces a, 6, ¢ were in each of the three posi- tions described in $14. There were thus nine combinations effected. In every case the suspended fork approached the stationary one. Hence, to whatever cause the approach is due, the action is mutual. § 16. The next question, the solution of which promised to throw light upon our problem, was this: What is the general or mean condition as to tension of a medium in which undulations are generated? Though this question has received very great attention from theoretical physicists, it has not been approached, as far as J am aware, from the side of experiment in the manner to be described. § 17. Experiment 7.—The fork A was fixed in an upright position in its sounding-box (fig. 4). One of its prongs was enclosed in a glass tube T, 0°4 m. long, and 0'042 m. internal diameter, carrying a cork through which the prong passed. ‘The upper end of T also carried a cork, through which passed a narrow tube ¢, bent twice at right angles, and dipping into ‘ water. The internal diameter of ¢ was 0'0035 m. The corks of the tube T were made tight with wax, and a little air was expelled from the tube T by warming it with the hand, so that when the atmospheric temperature was regained, the water stood at some distance up the tube ¢. The tube é Mr. F. Guthrie on Approach caused by Vibration. a9 was firmly clamped in several places to prevent vibration, and consequent Fig. 4 centrifugal effect. On passing the bow across 7, the enclosed prong was also set in vibration. When the amplitude of the vibration was as great as possible, the water had sunk in the tube ¢ to the amount of 0:003 m. The moment both prongs were suddenly stopped the level of the _ water in ¢ was restored.. The depression of the water in ¢ cannot be due to in- creased temperature; for, if it were so, the increase of volume would be gradual and accumulative, and, on stopping the vibration, the contraction due to cooling would be also gradual; whereas the at- tainment of maximum depression and the restoration to normal volume are prac- |__ tically instantaneous. § 18. We have here accordingly an experimental proot that the rapid motion (in this instance vibration) of a body in a medium produces on the whole an effect similar to that which would be produced by the expansion of the body, namely, a displacement of the medium. If air were perfectly elastic and had no inertia, no such total displacement could ensue, and I think I may safely predict that the apparent expansion of the medium will be found, in the case of hydrogen less, and in the case of carbonic acid greater than in that of air*. § 19. Though we know the dimensions of the fork and its rate of vibra- tion, and though we can measure with tolerable accuracy the amplitude of its vibrations, we can only calculate from this the mean velocity of any given point, because in the middle of a vibration the fork is moving very much faster than towards the commencement or termination. Hence this vibratory displacement cannot, with our present data, be connected with the known rate at which air enters a vacuum. §20. The fundamental experiment of §$1, 12 next suggested for its explanation the following question. Let there be two equal and opposite forces, P and Q, producing equilibrium upon a body having inertia; let one of them, P, be increased and diminished by a series of equal increments and decrements following one another in rapid succession. Will the con- tinually varying force, whose mean is P, maintain average equilibrium with the unaltered force Q? The plane of the cardboard in § 1 and § 12 is the seat of two opposing forces, namely the pressure of the atmosphere on both sides. When the sounding-fork is held on one side, the pressure on that side undergoes successive equal increments and decrements. Accord- ingly, if the question just proposed be answered in the negative, a suffi- * Compare the sighing of an organ pipe after it has been sounded. 40 Mr. F. Guthrie on Approach caused by Vibration. cient ground would be at hand for the approach of the cardboard to the fork. § 21. Experiment 8.—A “ Cartesian diver’? was made out of a test- tube, a bubble of air, and a beaker-glass of water. This was so nicely adjusted that it rose when near the surface of the water, and sank when the top of the tube was 0°05 m. below the surface. When resting on the bottom of the beaker, the top of the test-tube was 0°067 m. below the surface of the water. When the diver was resting on the bottom of the beaker, the tuning-fork A, in a state of vibration, was presented to the glass in various directions with regard to the tube. The fork was placed sometimes in contact with the water, sometimes in the neighbouring air, and sometimes in contact (towards the base of the fork) with the glass. Although the vibration of the bottom of the beaker caused the diver to leap up it invariably sank again, and showed no sign of undergoing any alteration in specific gravity. If, now, the question in § 20 were answerable in the negative, the equilibrium would have been destroyed, because the atmosperic pressure on the one hand, and the elasticity of the confined air on the other being equal and opposite forces, an alteration in one caused by its subjection to successive sonorous waves, would have altered the volume of the confined air and so destroyed the equilibrium. § 22. I hoped to throw light upon the fundamental experiment of § 1 and § 12, by varying the nature of the surface of the body which received the vibrations, with the view on the one hand of preserving them, and, on the other, of dispersing them as much as possible. With this view expe- riments 9-12 were undertaken. § 23. Eaperiment 9, fig. 5.—Upon one end of a splinter Figs. 5. of wood 0°5 m. long, a cylinder of cardboard 0:03 m. in diameter and 0:04 m. deep, closed at the bottom, was fastened in such a manner that its axis was horizontal, and its bottom in the plane V. The cylinder was coun- terpoised, and the whole was hung from an unspun silk thread. The vibrating-fork A was brought near the open end of the cylinder in the three positions already de- scribed, and also with one prong inserted into and nearly touching the bottom of the cylinder. In all cases motion towards the fork ensued. § 24. Haperiment 10.—A handful of cotton-wool was hung upon the splinter in place of the cylinder of experi- ment 12. The cotton-wool moved towards the fork from a distance of at least 0°05 m., when the latter was presented to it in either of the three positions, § 8. Muslin and washleather behaved in a similar manner. § 25. Experiment 11.—A circular paper drum 0°25 m. in diameter having a rim 0°025 m. deep, was hung by a silk tape in the same manner as the cylinder of § 23. Parchment was stretched across the wide end of Mr. F. Guthrie on Approach caused by Vibration. Al a funnel 0:2 m. in diameter. The neck of the funnel was placed in the mouth, and the drum of the funnel was brought opposite and parallel to the edged face of the paper drum. Air was rapidly forced into and drawn out of the funnel. The paper drum moved towards the funnel even from a distance of 0:1 m. § 26. Experiment 12.—A sheet of cardboard 0:4 m. square was hung in the plane V from a rod 1:0 m. long. The cardboard was counterpoised, and hung from a silk tape. The paper drum of § 25 was placed 0°05 in. from the cardboard, and parallel to it, and was then thipped. The card- board moved towards the drum. § 27. Experiment 13.—A rod of brass 1:2 m. long, provided at the ends with disks of brass perpendicular to the rod 0°26 m. in diameter, was set in longitudinal vibration by means of resined leather. One of the disks was held, during the vibration, near to the cardboard of § 26, also near the cotton-wool and muslin of § 24. In all cases the suspended body moved towards the disk. By this means it was easy to cause motion when the two were at the distance of,0°2 m. § 28. I have in the foregoing paragraphs sought to eliminate systema- tically secondary and disturbing influences from the fundamental experi- ment. The experimental results appear to me to poiut to the following conclusions. Whenever an elastic medium is between two vibrating bodies, or between a vibrating body and one at rest, and when the vibrations are dispersed in consequence of their impact on one or both of the bodies, the bodies will be urged together. The dispersion of a vibration produces a similar effect to that produced by the dispersion of the air-current in Clement’s experiment, and, like the latter, the effect is due to the pressure exerted by the medium, which is in a state of higher mean tension on the side of the body furthest from the origin of vibration than on the side towards it. In mechanics,—in nature there is no such thing as a pulling force— though the term attraction may have been used in the above to denote the tendency of bodies to approach, the line of conclusions here indicated tends to argue that there is no such thing as attraction in the sense of a pulling force, and that two utterly isolated bodies cannot influence one another. If the zetherial vibrations which are supposed to constitute radiant heat resemble the aerial vibrations which constitute radiant sound, the heat which all bodies possess, and which they are all supposed to radiate in ex- change, will cause all bodies to be urged towards one another. 42 Mr. Ll. Todbunter on Jacobi’s Theorem. On Jacobi’s Theorem respecting the relative equilibrium of a Revolving Ellipsoid of Fluid, and on Ivory’s discussion of — the Theorem.” By I. Topuuntsr, M.A., F.R.S., late Fellow of St. John’s College, Cambridge. Received November 28, 1869*. 1. The late James Ivory contributed to the Philosophical Transac- tions various memoirs on the subject of the equilibrium of fluids and the figure of the earth: the memoirs will be found in the volumes for 1824, 1831, 1834, and 1839. Ivory objected to the received theory of the equi- librium of fluids, and advocated some peculiar opinions at great length, and with much repetition. I do not propose now to criticise these memoirs ; I will merely state that I consider them to be altogether unsatisfactory. 2. There is, however, one theorem in the general subject to which I now propose to draw attention, namely, Jacobi’s theorem respecting the possibility of the relative equilibrium of an ellipsoid of fluid having three unequal axes and revolving about the least. Ivory discussed this theorem, and his errors are so numerous and so singular, that I have thought it would be desirable to place the corrections before the Society which origi- nally received and published Ivory’s communications. In correcting Ivory’s errors and supplying his defects, I shall add something to the discussions which have hitherto been given of the theorem itself. It will be seen as we proceed that one of Ivory’s errors has been already noticed and corrected. 3. Ivory first alluded to the matter in the memoir of 1834, which was read to the Royal Society a few months before Jacobi announced his discovery of the theorem. Of course at that date Ivory held the common opinion, that the relative equilibrium of a revolving ellipsoid with three unequal axes was impossible. But he does not merely acquiesce in the erroneous opinion, he attempts to demonstrate it in the following manner :— ‘Further, the figure of the fluid in equilibrium can be no other than a spheroid of revolution. Draw a plane through the axis of rotation and any point (wyz) in the surface of the fluid. This plane will contain that part of the attraction of the spheroid which is parallel to the axis of rota- tion, or to the coordinate x: it will also contain the centrifugal force directed at right angles from the axis of rotation. The same plane will also contain the resultant of the attractions parallel to y and z; for if it did not, the resultant might be resolved into two forces, one contained in the plane, and the other perpendicular to it; and the force perpendicular to the plane would partly act in a direction touching the surface of the spheroid, which is inconsistent with the equilibrium of the fluid. Where- fore, the whole attractive force at any point in the surface of the spheroid is contained in a plane passing through the point and the axis of rotation ; * Read Jan. 20, 1870. See vol. xviii. p. 171. Mr. I. Todhunter on Jacobi’s Theorem. 43 which obviously excludes ellipsoids with three unequal axes, and limits the figures of equilibrium to spheroids formed by the revolution of an ellipsis about the axis of rotation;...” The error here begins with the sentence which I have put in italics; the | resultant of the attractions parallel to y and z need not act in the plane which Ivory specifies : the component which he obtains ina plane touching the surface may be balanced by a like component arising from the attrac- tion parallel to x and the the so-called centrifugal force. 4, To the Philosophical Transactions for 1838 Ivory contributed a memoir of ten pages on Jacobi’s theorem. Ivory devotes a few sentences to the history of the matter. He records the fact that Lagrange had inferred that the figure of relative equilibrium must be a figure of revolu- tion. He makes no allusion, however, to his own erroneous demonstration in the volume for 1834. 5. The object of the memoir seems to be twofold—to establish Jacobi’s theorem, and to deduce numerical results relating to the extreme possible cases analogous to those which had long been known relating to the extreme possible cases for an ellipsoid of revolution.. The first object is attained ; Jacobi’s theorem is demonstrated in a manner resembling that which had previously been used by Liouville. The second object Ivory fails to attain, owing to an error in his process. 6. Inthe second page of the memoir there is an error in mechanics re- sembling that which we have already noticed in Art. 3. At any point in the surface of an ellipsoid, let the normal to the surface be drawn; and let it be terminated by the principal plane which is perpendicular to the axis of rotation: let p be the length of this straight line. At the same point in the surface draw a straight line in the Breeton of the resultant of the attraction of the whole mass of the ellipsoid, and let it be terminated by the same principal plane ; let p! be the length of this straight line, then Ivory says :— “‘ Let o denote the third side of the triangle which has p and p! for its other sides: then o will represent the only force which, together with the attractive force p’, will produce a resultant in the direction of p at right angles to the surface of the ellipsoid.” This statement is quite wrong. Any straight line which is in the same plane as the normal at any point, and the direction of the resultant attrac- tion at that point, may be taken for the direction of such an additional force as Ivory requires; and the magnitude of the force can then be properly determined. i 7. In order to render the discussion of Ivory’s memoir readily intel- ® ligible, it will be necessary to indicate briefly the demonstration of Jacobi’s theorem. Let the equation to an ellipsoid be y — /; yes ear son q AA, Mr. I. Todhunter on Jacobi’s Teekicas The attractions which the ellipsoid exerts on a point (#, y, z) parallel to the axes of coordinates are known to be respectively Av, By, Cz, where AaoM(Medu piSM(t wdu G@_3M(?__ wdu Jo HB Jo (LEN WV Yo 1+ pt) Here M denotes the mass of the ellipsoid, and H stands for V(1+d2u?) (1 + p2u?) : see the ‘ Mécanique Céleste,’ Livre III. No. 7. Take the axis of w for that of revolution, and let w be the angular velocity. Then the necessary and sufficient condition for relative equi- librium is that the equation Awdz+(B—w*)ydy +(C—w’*)zdz=0 should coincide with the differential equation to the surface of the ellipsoid, namely, ydy +5 zdz l + ne + pe i Hence we have the conditions Boo Cok 1 (1) A l Az rh? A l oe e ° ° e ° ° If we eliminate w? between these we obtain (1+2’) (l+p°) (B—C)=A(w*—d’). 2 ww (2) But from the values of B and C we have 3M 7st he. Eds B—C=— (p—d ae, ge Ce (, TE Thus (2) becomes wey {ee Ce) (SB () pes This may be satisfied by putting »”=)’, which gives us an ellipsoid of re- volution. Or it may be satisfied by making 2 a ( tutdu (udu | ext) | (ae, this may be reduced to 1 y?(1—u’) (1—D?p?u?)du _ {iQaog ee =), We have then to show that for suitable values of \ and p this relation will hold. This will be shown in the sequel. We must also show that the value of w? is positive. From (1) we have ) B—w eae Cac Ae rdx+ Mr. I. Todhunter on Jacobi’s Theorem. A5 so that pa Bee BN’ — a v—p? De —pe Put in the values of B and C, and this reduces to 2 _ 3M (' aU —w*)du Tae so that w” is positive. 8. Before considering Jacobi’s theorem, we will advert to the case in which p’=)’. We have from (1) Hi A rd a 5 LX let p be the density of the ellipsoid, then M= Ampk*(1 2a 3 = Put g for 4zp ; thus “ _opl 1 ve’ (1—2’)da ad ee (4) Here we have changed u into w, and d into J, in order to have the same notation as Ivory has. Ivory says: * From the equation (4) we learn that q will be known when J is given, or that every spheroid of a determinate form requires an appropriate velocity of rotation. “‘The inspection of the same equation is sufficient to show that q is positive for all values of 7°; and as it vanishes both when 7’ is zero and infinitely great, it must pass at least once from increasing to decreasing, or it will admit of at least one maximum value. By differentiating with regard to / we obtain dq =|" 30°(1—a") (1—Pa")dx (5) dt, (+P) iia bikie from which formula we learn that = is positive between the limits 7’=0 and J*=1; that it will consist of a positive and a negative part when 7° is greater than 1; and the positive part decreasing while the negative part increases, that it will ultimately be negative when 7° is infinitely great. It follows therefore that = can be only once equal to zero, and conse- quently that g can have only one maximum value, while 7’ increases from Piao.” This is quite unsound, because the words which I have put in italics are untrue, There are two ways of separating the integral into a positive part and a negative part. We may take for the positive part the integral 46° Mr. I. Todhunter on Jacobi’s Theorem. between the limits 0 and ~ and for the negative part the integral between the limits : and 1. Or we may put the integral in the form Lae*(l—a’)da a»( x*(1—x’)da 2 = 1 cera PE ees Takin Un Moca a ae a o (are) 0 (14+0a")? I do not know which of these two ways Ivory adopted. It is true that in each of them the positive part decreases as / increases ; but in each of them the negative part is finite when J is finite, and is infinitesimal when 7 is in- finite, and so does not always increase with Z as Ivory supposes. 9. However, although Ivory’s reasoning is unsound, the result which he wishes to establish is correct, as I shall now show. La’(1—a’) (1—Pa*) da Consider the integral { a at eee as J increases from unity to infinity, the integral vanishes and changes sign once, and only once. It is obvious that the integral must vanish once, because it is positive when /=1, and negative when/=« : it is indeed infinitesimal in the latter case, but the sign is certainly negative. Put z for dv; thus the integral becomes 4, 2(P—2) (l—2 dz _ w ay, PN +2) is We have to show that the equation w=0 can have only one root between J=1and/=x. If the equation could have more than one root it must We have to show that have three roots at least; and then the equation a= must have two roots atleast. Now du L2(1—2\dz — =21 Ss pee p) ’ Hl \, a2) 2lv, say dv_?U—?P) di (1+7)*" Thus v is positive when 7=1, and while J increases = is always negative ; and thus v continually diminishes algebraically, and so cannot change sign more d ; ae ‘ than once. Hence “7 cannot vanish more than once; it will vanish once because v is positive when /=1, and has a finite negative value when /=c , namely, T {° sin *@(1—2 sin°@)d0, that ‘ee 0 10. There is also another way in which the result may be established. For from (4), by the known method of integration, we have Mr. I. Todhunter on Jacobi’s Theorem. 47 gett! tan-1 raed oP? therefore _dq_ 309942 1, 809+ 70) dl oF 21+ Fe Thus - vanishes when 3 iy eae eater oe (Gat) Ivory gives these formule with some misprints. Now it has been shown by Laplace that the equation (6) has one positive root, and only one, namely, when /=2'529.... See the ‘ MécaniqueCeéleste,’ Livre III. No. 20. 11. We now return to Jacobi’s theorem. We take the integral in (3), and put x for «'; we put A—=r, and we may suppose ) greater than p, so that r is positive; and we put\y=p. Thus (3) becomes | eee i) 0 (Lt pey frat} Denote the left-hand member of (7) by V; then we propose to examine the range of values of p and 7 which make V vanish, supposing both p ‘and 7 positive. If we regard p as an abscissa, and r as an ordinate corre- sponding to p, we in effect propose to trace in the first quadrant the curve determined by the equation V=0. (12. If we put 7=0, the equation (7) becomes i vas Me tae ON) \ oC aA! ae ee e e e e ° (8) 0 (1 -bpay: Ivory says: ‘‘It is obvious that there is only one value of p that will verify the equation just found; for the integral can pass only once from being positive to be negative while p increases from 1 to be infinitely great.” | I cannot admit that this assertion is obvious; the result, however, may be established by the following investigation :— Denote the integral by u; as long as p is less than unity, u is positive, and when p is infinite wis negative. Thus «w must vanish once as p changes from unity to infinity : we have to show that w can vanish only once. If the equation «=0 could have more than one root, it must have three ood roots at least; and then the equation — =0( must have two roots at least : this we shall show to be impossible. | We have du_ ft a*(1—2") (84 2p—p’a")da | dp 0 (1+ pa") { AS Mr. I. Todhunter on Jacobi’s Theorem. ; 2 m it is obvious then that z cannot vanish until 3 i op is greater than unity, ire du . : that is, until pis greater than 3. Thus ip is negative when p=3; and we can see that ii is positive when p=oc. Hence zs changes sign once as p increases from 3 to infinity. Put px’= tan’d, and let p= tan’B; thus : B att Chime { sin’ (p cos’ — sin?) | 1—(3+ ) cos*s } do =, say. 2 De dp p3\o cos’0 Then we know that v is negative when p=3, and positive when p=x. If, then, the equation v=0 could have more than one root, it must have three roots at least, and then the equation 2p must have two roots at least. dp Now a9) dv _ { : sinto( ee ee "0, dp 0 P Can De ene (p—3) vp SSS Sy) be ee : dp a TO Ep) Thus = is always positive when p is greater than 3, and therefore © P continually increases, and so cannot vanish more than once. Hence v cannot vanish more than once, and therefore ~ cannot vanish more than once. Thus wu is always negative when p has any value greater than that which makes w vanish. 13. There is also another way in which the result may be established. It will be found that eee (l—p*e')dx_3+13p_3+14p+3p* ..-1 ,- 2)\3 oi in TC eGae Vp. 0 (1+ pz") Sp Sp2 Then it may be shown that the last expression will vanish once, and only once, as p changes from 1 too. This method is adopted by Liouville in an article in his ‘Journal de Mathématiques’ for April 1839: the article consists of observations on the memoir by Ivory, which we are discussing. Liouville says that the value of », which makes the last expression vanish, is a little less than 2. Ivory has a formula which is equivalent to this, but he does not employ it to show that there is only one value of p; for he had already, as we have seen, stated this to be obvious. From the circumstance that Liouville gives a strict demonstration, it is plain that he agrees with me in thinking that Ivory’s statement is not obvious. According to Ivory, the value of p which satisfies (8) is 1:9414.... We will denote this by p,. 14. I shall now show that if we ascribe to p any value greater than p,, a corresponding value of r exists, which will make V vanish. Mr. I. Todhunter on Jacobi’s Theorem, 49 Let such a value be ascribed to p; then from Art. 12 it follows that, with this value of p and with +r=0, the value of V will be negative: we shall now show that by taking 7 large enough V will be positive, ve 1 (1 —2*) (1l—p*e*)dx . Jo {1+ (2p-+r)a* + pat} thus the sign of V is the same as that of 1g?(1—x’*) (l—p’2”)dax i! (c+ a+ prern')2 where c° stands for : i 2p-+7 When cis made small enough, the term p’c** may be neglected in com- parison with z*; and so the sign of the integral wiil become the same as that of Lat —a*\de _(' pai(1—2’)de 0 (ce? +x") {, (c+ 2°)3 The first term is infinite when c=0, and the second term is finite; thus the sign of the integral is positive when c is small enough. Since V is negative when 7=0, and is positive when 7 is large enough, it must vanish for some intermediate value of r. 15. Moreover, when c is very small, we have approximately 1 y*(1—x’)da Vases 2 {, w(—#')de _ log aan log (c’+w’)2 © c cee. 1 pat] —x da _ Pp 0 (e?+.2°)2 4 Thus to make V vanish when - is very large, we have approximately 2 Agia celle therefore 2(2p+r) et 2; so that approximately p83 rodet 2, 16. We shall next show that corresponding to a given value of p there is only one value of r which will make V vanish. Put ; A’ss(l4+ pe’) +7e’, P?=(1+p)’-+7r’; C1 — i”) (1 —pu)= A? m= P?2", . 1 y'dax ol tatda tieare ty 1” ft) Qo 4 Q VOL. XIX. E then Thus we have 50. Mr. I. Todhunter on Jacobi’s Theorem. and therefore Hence = dV 1 y?*dax Pn?\* , Vrs 2 oT (' <0 a) ar) a e ® e e (9) The right-hand member is necessarily positive. If we put o=r’, we may write the equation thus, oe ‘L a 0-3 -) ae. A This shows that if p be kept constant, VP* continually increases with 6; and therefore cannot vanish more than once, and therefore of course V cannot vanish more than once. 17. Ivory makes the following statement :— “‘ Let V stand for the integral in the equation (7); and supposing that p and 7° vary so as always to satisfy that equation, we shall have = ~ap+Trdr=0. Now, 7 representing Re positive quantity, we may conceive it to increase from.zero.to be infinitely great ; in which case it follows from the nature of the function V, that during the whole increase TO ede eit ; TAT will be negative Delete the other term a will be positive; which requires that p decrease continually.” It is here in fact asserted that a is negative for such values of p and 7 as make V vanish; this is, however, wrong, as equation (9) shows that = is positive when V=0. The mistake was pointed out by Liouville in the memoir already cited, and the correction was accepted by Ivory in the Philosophical ‘Transactions for 1839, pages 265, a ave mistake vitiates the remainder of Ivory’s memoir. The investigation of Art. 16 is taken in substance from Thole 8 memoir; he also demonstrates the proposition of Art. 14, but not in the way en I have adopted. — 18. The extract given in the preceding article from Ivory’s memoir involves another error, which Liouville does not notice: the words “which - requires that p decrease continually,’ contain an arbitrary unproved asser- tion. We have ON . dV dp Pahari dp : hence if Fe Were negative, do & would be positive; then a might be Mr. I. Todhunter on Jacobi’s Theorem. 51 tL , or it might be negative: we cannot assert at once, as Ivory does, that 2 ! must be negative, Suppose, for example, that V stood for p*—7r°—1; then wv would be negative for positive values of 7, and p would continually zs d increase with r. 19. As I have already stated, Ivory accepted the correction made by Liouville; but in the two pages in which the mistake is acknowledged other untenable assertions are advanced. It was in effect necessary for Ivory’s purpose to trace the curve determined by V=0 in the first quadrant ; but instead of demonstration such as we have supplied in Art. 14, Ivory gives unwarranted assertions of the kind already noticed in Art. 18. We have | Waite ae foe ae | ate + 2p—p'x") (1+pex’) + 2pr'e'sde, from which it follows that, whatever positive number 7° stands for, is negative for all values of p that make 3+2p—p’ positive, that is, for all values of p less than 3. This Ivory gives, and so far he is correct ; _ is certainly negative, and not zero, so long as p is less than 3. Ivory wishes to show that al can never bezero. He takes the differential equa- tion dV. av ——dp + ——rdr= dp 7 ge an he says, “Further, in the differential equation Fcnnnot be zero ; because, 7 increasing without limit, ONedr is essentially positive.” TAT This is quite unsound. Regard p as the abscissa and 7 as the corre- sponding ordinate of a curve determined by V=0; then assuming that os is always positive, yet = may vanish; that is, there may be a point’ v 'P or points on the curve at which the tangent is parallel to the axis of abscisse. Suppose, for example, that V stood for P—p?+4ap’—hap—B’ ; then is always positive, = is negative when p is less than a, and vanishes when p=a or = _ I do not assert that = can vanish in the present case ; I only maintain that Ivory’s argument to show that cannot vanish is unsound. I shall Ne E 2 52 Mr, I. Todhunter on Jacobi’s Theorem. | dV presently demonstrate that we cannot vanish. 20. Ivory concludes the two pages in the Philosophical Temgepmee for 1839 thus :— Tf the sign of = be changed, the result will be positive ; and hence, Tp observing that wv is contained between 0 and 1, we obtain a condition between any two values of p and 7* that satisfy the equation (7), namely, the ex- pression (S+p—p") (1 +p)+ 2pr* must be a positive quantity, or, which is the same thing, P>(p apts) te This is obscure in its commencement ; but Mh statement to which it pro- ceeds is intelligible, but is unwarranted. For, granting that iy is always to be negative, this will be secured if | (3+ 2p—p°u*) (1 +pa") + 2pr*a* is always positive ; that is, if 3+ 2p + (3p +p" + 2pr’)a* — pia" is always positive ; that is, if 3+2 — + 3p+p*-+2pr—pix is always positive. And as x lies between 0 and 1, this condition is cer-- tainly secured if 34+2p+3p+p’+ 2pr* is greater than p’. According to Ivory’s statement it would be necessary that 3+4p+2pr? should be greater than p? ; whereas we see that it would be sufficient that 3+5p+p*+ 2pr* should be greater than p’. Ivory’ s second statement is inconsistent with his first, but becomes con- sistent with it if we change +3 to —3; if, however, his second statement is to be taken as what he intended, and his first statement corrected to agree with it, his error is aggravated. In fact, however, I doubt whether any such necessary criterion as Ivory proposes can be easily deduced from the value of For, granting that i S is always negative and never zero, it will not follow that every ele- e ° e dV v mené in the integral which expresses ip must be negative, but only that the “ i es Mr. I. Todhunter on Jacobi’s Theorem. 53 ageregate of the positive elements, if such there be, should fall short of the aggregate of the negative elements. However, be this as it may, there can be no doubt that the specific criterion which Ivory proposes is quite unsupported by demonstration. When p andr are very large, the relation between them is approxi- mately that given in Art. 15. 21. In Arts. 14 and 16 it is shown that for every given value of p greater than p,, there is one, and only one, value of 7 which will make V vanish. We shall now show that corresponding to every value of 7 there is one, and only one, value of p which will make V vanish. Whatever be the given value of r, it is obvious that V is positive when p=0, and negative when p is large enough: thus there must be some in- termediate value of » which makes V vanish. We have then to show that there is only one such value; to show this we shall demonstrate the proposition which Ivory asserted on insufficient grounds, namely, that = can never vanish simultaneously with V. (0-2) | aS lies ao {, are te OP Le opr le Be jaws dV : and we know that a cannot vanish so long as p is less than 3. See Art. 19. We shall first show that the limit p=3 may be changed to a larger limit. If the integral 4 { wo (1—2x°) {34 2p+ (3p +p? + 2pr’)a? —pru' da 0 is positive, the integral will also be positive when A’ is introduced as a divisor under the integral sign ; for by introducing this denominator we diminish all the elements of the integral, but we diminish every negative element in a higher degree than any positive element. Now the value of the last integral is 2(3+ 2p) , 23p+p?+2pr*)_ 2p? 5x7 7x9 9x11 we are certain that this is positive if 2p +p?+3p , 342). eelitee a t th ae tae is not less than as 9x11 that is, if r4iP a is not less than = On trial it will be found that this condition is satisfied, even when r is zero, provided p be not greater than 41. Thus we have ouly to consider 54 Mr. I. Todhunter on Jacobi’s Theorem. the case in which both p is greater than 44, and r — 498+ 2p) 10p 2 is less than S ; and we have to show that ‘ib is negative in this case. 1 : Put ae ; thus V becomes a function of g and; and we have to show that Tr cannot vanish when gq lies between 0 and = > and a 9(3q+2) - 7 » _, 3g+))q _, 9(89+2 + 2\"2 7 *?/ is less than ——., so that 7r7q° Wy Na g Rica | q4+2)7 =. 10 220° ce! 9 == i0 1s less a than = We have v= (1—2") (¢’—a2? = D? where D? stands for g°+ 2qu°+'+9°7°x" ; therefore = aN oN 1 ¢(1—«a’) 3(¢?—2?) f cE (|=: 2) 2 Sag) | ag q gS) ae dq gq A) D? [ q D? dx. Separate the integral into two parts, one-extending between the limits x=0 and w«=gq, and the other between the limits w=q and v=1. Itis obvious that the second part is positive, so that we have only the first part to examine; this is Es am ee ae ; i z {. a | —9G+(8q¢4+ 9 —7'¢)a? + (384 2¢4+ 3977) a* } dx aud we shall show that this is positive. Let Q stand for —P+(3q+9¢—7'¢q))x + (34+294+3qr*)a! then we shall first show that i (1—2x* )Qda is positive ; and next that 9 #@°(1—a*)Qda 0 be is positive. Now Ke —«*)Qdx will certainly be positive if 0 q 2 2 2 9 i, (l—a’) {-—9+(3q4+ 9 —7 7 )xe + 3qr'a*}da is positive. The last integral is iat Jef bleu (Oe. @" (1 5) +(30+9 *e\(5 1) s0(f- ") Mr. I, Todhunter on Jacobi’s Theorem. ... -- 55 that is, ¥ (144 0 a 10); E(1-3-)+ LY; and this is positive, for g does not exceed < Now the coefficient of a* in Q is positive, since r°q° is less than 53 and thus Q cannot change sign more than once; it changes sign once, for it is negative when «=O, and positive when v=q. ‘The factor _ will be found to increase continually as x increases from 0 to g. Hence in q 1 07(1—2*)Qad: passing fom ( (1—2’)Qda tof a a larger fraction is taken 0 0 of every positive element than of any negative element ; so that since the former integral has been shown to be positive, the latter is necessarily positive. | To demonstrate that = = coatinaally. 3 increases as & increases from 0 to q, dD take the differential coefficient with respect to «; the sign of this differ- ential coefficient is the same as that of } 20D? —52?(2qe+q°7°v + 22%), that is, of 2D?— 5a°(2¢+¢77?+ 20), that is, of 2¢? — (69+: 397r")a*? — 8.24 ; this is positive when e=0; when v=q it becomes q?(2—6q—3q?r?—8q°), which we shall now show to be positive. We have by supposition 37°¢? 24 0 +5if less than 5, and sr anroratB(8 + 3q'r'+8¢') Pall sre. and as q does not exceed ~ = q this 1 is greater than 2— 36 23 and so is positive. Hence we see that when V=0, the value of ig is necessarily positive, and cannot be zero. 22. We have shown in the preceding Article, that cannot vanish P simultaneously with V; the demonstration is rather complex, and perhaps for this reason Ivory attempted to establish the proposition by unsound general reasoning. Liouville does not give the proposition, although it is naturally required to make the discussion of the admissible values of p ‘and 7 complete. 23. Thus we may state the results of Arts. 14, 16, and 21 in the AL 56 Mr. J. M. Heppel on the Theory of Continuous Beams. lowing manner :—If the curve determined by the equation V=0 be traced in the first quadrant, every straight line parallel to the axis of p meets the curve once, and only once, and every straight line parallel to the axis of r, and at a greater distance from it than p,, meets the curve once, and only once. Ass vanishes with 7, the curve meets the axis of p at right angles ; a and from Art. 15 it follows that when 7 and p are indefinitely great, the angle which the tangent to the curve makes with the axis of p is very nearly a right angle. Thus, for small values of 7 the curve is concave to the axis of p, and for very large values of r the curve is convex to the axis of p; so that the curve must have a point or points of inflexion. 24, In the very careful account of Ivory’s mathematical researches, which is given in the fourth volume of the ‘ Abstracts of the Papers .. . of the Royal Society,’ it is said, with respect to Jacobi’s theorem, “In a paper in the Transactions for 1838, Mr. Ivory has with great elegance demonstrated this theorem, and has given, with greater detail than its authors had entered on, several statements regarding the limitations of the proportions of the axes.” The language is cautious, but seems to imply some suspicion with regard to the accuracy of the statements. As we have now seen, many of Ivory’s statements are inaccurate, and others, though accurate, are based on unsound reasoning. “On the Theory of Continuous Beams.” By Joun Mortimer Heuprret, M. Inst. C.E. Communicated by Prof. W. J. Mac- QUORN Rankine. Received December 9, 1869%. In venturing to present to the Royal Society a paper on a subject which has engaged the attention, more especially in France, of some of the most eminent engineers and writers on Mechanical Philosophy, the author feels it to be incumbent on him to state the nature of the claim to their attention which he hopes it may be found to possess in point of originality or im- provement on the method of treatment. To do this clearly, however, it will be necessary to advert to the principal steps by which progress in the knowledge of this subject has been made, both in France and in this country. The theory of continuous beams appears to have first attracted attention in France about 1825, when a method of determining all the conditions of equilibrium of a straight beam of uniform section throughout, resting on any number of level supports at any distances apart, each span being loaded uniformly, but the uniform loads varying in any manner from one span to another, was investigated and published by M. Navier. This method, although perfectly exact for the assumed conditions, was objection- able from the great labour and intricacy of the calculations it entailed. * Read January 27, 1870. See vol. xviii. p. 176. Mr. J. M. Heppel on the Theory of Continuous Beams. 57 Messrs. Molinos and Pronnier, in their work entitled ‘ Traité Théorique et Pratique de la construction des Ponts Métalliques,’ describe this process fully, and show that for a bridge of n openings, the solution must be effected of 32+ 1 equations, involving as many unknown quantities, these equations being themselves of a complex character ; and they observe, “ Thus to find the curve of the moments of rupture for a bridge of 6 spans 19 equations must be operated on; such calculations would be repulsive, and when the number of spans is at all considerable this method must be abandoned.” * The method of M. Navier, however, remained the only one available till about 1849, when M. Clapeyron, Ingénieur des Mines, and Member of the Academy of Sciences, being charged with the construction of the Pont d’Asniéres, a bridge of five continuous spans over the Seine, near Paris, applied himself to seek some more manageable process. He appears to have perceived (and so far as the writer is informed, to have been the first to perceive) that if the bending moments over the supports at the ends of any span were known as well as the amount and distribution of the load, the entire mechanical condition of this portion of the beam would become known just as if it were an independent beam. Upon this M. Clapeyron proceeded to form a set of equations involving as unknown quantities the bending moments over the supports, with a view to their determination. He found himself, however, obliged to introduce into these equations a second set of unknown quantities (‘‘ inconnues auwiliaires’’), being the inclinations of the deflection curve at the points of support, and not having arrived at a general method of eliminating these latter, was obliged to operate in each case on a number of equations equal to twice the number of spans. M. Clapeyron does not appear, as yet, to have made any formal publication of his method, but to have used it in his own practice, and communicated it freely to those with whom he came in contact. In 1856, M. Bertot, Ingénieur Civil, appears to have found the means of eliminating this second set of unknown quantities n+ 1 in number for a bridge of spans, and thus reducing the number of equations to n—1. Each of these equations involved as unknown quantities the bending moments over three consecutive supports, and was considered, from its remarkable symmetry and simplicity, to merit a distinctive name, that of “The Theorem of the three Moments.” The method, however, to which this theorem is the key, is still every- where called that of M. Clapeyron, and, as it appears to the writer, justly so, as it was an immediate and simple result from his investigations, with which M. Bertot was well acquainted. The next important advance was made in 1861, when M. Bresse, Professeur de Mécanique appliquée & Ecole Impériale des Ponts et Chaussées, completed the matter of the third volume of his course, which is exclusively devoted to this subject*. M. Bresse explains and de- * This was communicated to the Academy of Sciences in 1862, though the volume was not published till 1865, | Ne ee a re 58 Mr. J. M. Heppel on the Theory of Continuous Beams. monstrates the theorem of the three moments, at the knowledge of which he had himself arrived from M. Clapeyron’s investigations, independently of M. Bertot. He then goes on to the investigation of an equation of much greater generality, in which what is termed by English writers “imperfect continuity ’’ is taken into account, being, however, there replaced by the precisely equivalent notion of original differences of level in the supports, the beam being always supposed primitively straight; besides this the loads, instead of being taken as uniform for each span, are considered as distributed in any given manner. : Having obtained this fundamental equation, M. Bresse proceeds to investigate the nature of the curves, which are the envelopes of the greatest bending moments produced at each point, by the most unfavourable distribution of the load in reference to it, and finally gives tables for the ready calculation of results in a great variety of cases, comprising most of those likely to occur in practice. During the time that M. Bresse was engaged in these researches, an imperial Commission was formed, of which he was a member, for the purpose of devising rules applicable to practice, and the results of his labours have been the basis of legislative enactments equivalent to our Board of Trade regulations prescribing the methods to be followed in determining the stresses in the various parts of the structure. About the same time that M. Bresse turned his attention to this sub- ject, it appears also to have engaged that of M. Bélanger, who in his work entitled ‘ Théorie de la Resistance et de la Flexion Plane des Solides &c., Paris, 1862,’ gives a very complete demonstration—resulting in an equation which in one point of view is slightly more general than that of M. Bresse, as it takes in variation of the moment of inertia of the section from one span to another. In another point of view its generality is slightly less, as it deals only with loads distributed over each separate span uniformly, whereas M. Bresse replaces the simple algebraical terms expressing these by definite integrals expressing the load as a function of the distance from one of the points of support. As far as the writer is informed, little has been done in France to advance this theory beyond the point to which it was brought by the writers last mentioned, and especially by M. Bresse ; but valuable contri- butions to its development in reference to application to practice are to be found in the work of MM. Molinos and Pronnier above referred to, as well as in various papers by MM. Renaudot, Albaret, Colignon, Piarron de Mondesir, &c. In England little or no attention appears to have been paid to this sub- ject by writers on mechanics till 1843, when the Rev. Henry Moseley, Professor of Natural Philosophy and Astronomy at King’s College, London, published his work on ‘The Mechanical Principles of Engineering and Architecture.’ In part 5 of this work, which treats of the strength of materials, four cases of continuous beams are fully investigated, and the - Mr. J. M. Heppel on the Theory of Continuous Beams. 59 general case is to a certain extent discussed, the method of M. Navier being perhaps rather indicated than fully developed. Prof. Moseley’s work was altogether a most valuable contribution to engineering science, and, as far as the present subject is concerned, no doubt furnished the groundwork of the method applied by Mr. Pole to the solution of other particular but more complex and difficult cases. The first case which engaged the attention of Mr. Pole appears to have been that of the bridge over the Trent at Torksey, consisting of two spans of continuous tubular beams, resting on abutments and a central pier. For special reasons it had become necessary that the real conditions of equilibrium of this bridge should be investigated with more than ordinary precision ; and this Mr. Pole did by a method virtually identical with that of M. Navier, though it does not appear that he had any previous know- ledge of that method, except through the medium of Moseley’s work. Throughout Moseley’s cases, however, the load on the beam is considered as distributed uniformly over its entire length, whereas Mr. Pole had to deal with the case of different loads on the two spans, and no doubt had to devise the method of analysis necessary for its treatment. Mr. Pole’s paper on this subject is published in vol. ix. of the ‘ Minutes of Proceed- ings Inst. Civ. En.’ 1849-50. As far as this went, however, it could hardly be considered to have advanced the theory of the subject, as M. Navier’s method included this case, and much more; but about the same time Mr. Pole had to investigate the case of a much larger work, the Britannia Bridge, where he had to deal with some new conditions, which, as far as the writer is aware, were then for the first time successfully treated. These were that, besides variation of load on the different spans, their cross sections also varied, and there was imperfect continuity over the centre pier, that is to say, that the points of support being supposed to range in a straight line, the beam if relieved from all weight would cease to remain in contact with them all, and would consist of two equal straight portions, forming an angle pointing upwards. The process, which for distinction may be called that of M. Navier, was skilfully extended by ‘Mr. Pole so as to include these new circumstances, and by its means results were obtained certainly true within a very small limit, and as near the absolute truth as any existing means of treating the subject would produce. Mr. Pole’s researches on this subject are published in Mr. Edwin Clark’s work on the Britannia and Conway Bridges, 1850. Both from the clear and accurate treatment of the case and the record of the numerous and delicate observations by which the theoretical conclusions were continually verified and kept in check, they are most strongly to be recommended to the attention of engineers having to deal with works of this character. _ The sequence of events now compels the writer to advert to some studies of his own. In 1858-59, being then Chief Engineer of the Madras Rail- 60 Mr. J. M. Heppel on the Theory of Continuous Beams. way, he had occasion to investigate the conditions of a bridge of five continuous spans over the River Palar. Having in India no books to refer to but those of Moseley and Edwin Clark, he found himself unable to extend the treatment of the cases there given to that of a beam with an increased number of openings and varying loads. After many attempts and failures, the same idea occurred to him which appears to have struck M. Clapeyron nine or ten years before, that if the bending moments over the supports were known, the whole conditions would become known. Following this clue, he was fortunate enough to succeed in at once eliminating the other unknown quantities, which M. Clapeyron had been cbliged to retain in his equations for many years after his original discovery of the method, and thus to arrive at an equation precisely identical with that which had been first published in France by M. Bertot in 1856, and was known as the “Theorem of the three Moments.” This was sufficient for the immediate purpose, as the beams in question were straight and of uniform section throughout, conditions to which this theorem is strictly applicable without any modification whatever. As, however, the writer was at this time under the impression that he was using an entirely new mode of analysis, he was naturally anxious to check its results by comparison with those obtained in some well-known case by other means. Fortunately he had at hand that of the Britannia ° Bridge, perhaps the best that could have been selected ; but for this purpose it became necessary to import into the fundamental equation the conditions of varying sections in the different spans and imperfect continuity. This, however, presented no great difficulty, and by means of an equation thus modified, he had the satisfaction of reproducing all Mr. Pole’s results, and thus convincing himself of the trustworthiness of the method in question. The equation thus generalized is absolutely identical with that arrived at by M. Bélanger in the work above referred to*. It would appear, then, that the theory of this subject was independently advanced to about the same state of perfection in France and in England, though as regards the development of its application to practice no doubt very much the more has been done in the former country. The writer will now advert to some inherent defects of this theory, the cure of which is the principal object of the investigation which follows. The chief one, which is admitted by all writers on the subject, is the necessity for supposing the moment of inertia of the section constant throughout each span ; any more general hypothesis, it is said, would render the calculation inextricable. Still it is certain that the conclusions arrived at on the hypothesis of a constant section cease to be true if a variation of section is introduced, and the amount of error thereby induced, though considered to be probably small, is still a matter of uncertainty. The next defect is the assumption of uniformity of load throughout * A paper on this subject by the writer was published in the Minutes of Proceedings Inst. C.H, vol. xix. 1859-60. Mr. J. M. Heppel on the Theory of Continuous Beams. Gl each span ; for although as far as rolling load is concerned no more correct hypothesis could be made, the weight of the bridge itself, if a large one, usually varies considerably in the different parts of the same span. The equation given by M. Bresse, as has been stated, provides for certain kinds of variable loads by the use of integrals, but the writer is not aware that they have been applied, even by that author himself, to the purposes of calculation, and it seems to him that in most cases the attempt to make such an application would be beset with difficulties. It will, however, it is hoped, be seen from what follows, that the dealing with variations of the above elements does not in fact present any very formidable difficulty, though no doubt the labour of calculation is greater ; but what the writer regards as most satisfactory is the very small difference in the principal results in the case of the Britannia (where these variations greatly exceed in amount those usually occurring), whether obtained by the approximate method hitherto followed, or by the more rigorous one to be explained, affording a strong presumption that in all ordinary cases the former method may be confidently employed without risk of any important error. Should the following treatment of the case be deemed successful, the author would remark that its success is mainly due to the use of an abbreviated functional notation, by which a great degree of clearness and Symmetry is preserved in expressions which would otherwise have become inextricably complex. General Investigation of the Bending Moments and Deflections of Continuous Beams. A a o UL 2 Let 1.2 represent any span of a continuous beam, the length of the span being /. #.y the coordinates of the deflection curve, the origin being at the point 1. a and 6 particular values of 2. € €,, €, reciprocals of the products of the moments of inertia of the sections in the spaces (1. a), (a. 6), (6.2), about their neutral axes, by the modulus of elasticity of the material (a) Hy» Ho» Hs loads per unit of length in the same spaces. T tangent of inclination of deflection curve at 1, to straight line join- ing | . 2, its positive value being taken upwards. $,. ¢, bending moments at 1. 2. P shearing force at 1. Now let the bending moment at any point (2. y) between 1 and a be called F,'(2), between a and 6 be called F,""(z), between 6 and 2 be ealled Ey: 62 Mr. J. M. Heppel on the Theory of Continuous Beams. and let the part of this bending moment, which results alone from the. load on the beam between 1 and 2, be called between 1 and a f(z), between a and 0 f,'(z), between 6 and 2 f,'"(2); and let the first and second integrals of these functions, as of F,"(v), f,(2), be denoted by F,'(2), f,(z), and F,(x), f(x), and the value of any one, as F(z), for a particular value of z, as a by F(a); ; en Pp en ee ne Ae@=na(o-$)\ ESP) oe es ® Wifes p—b f Ai @)=na(e—$) + nb—@)(e—-"F*) +S, « B) Also, from equality of moments about the point (w. y), FY (@)=¢6,—Pa+f (2). eee F"(@)=¢,—Pat+f,'(#), OE ee eee! (5) F,'(@)=6,—Pe+f," (2); . » eee and, from equality of moments about the poiut 2, Pl=$,—$.+f5 (1); 1 " » P= (i be4/ ). a Substituting for P in (4), (5) and (6), B"(@)= (1-7) n+ Fo.— OK + ++ + @ F@)= (1-9) 4 F6.- OLN - ee B@= (1-9) it FOO - ee iL equations from which for a given value of w, F,'(«), F,'(), F,"(#) may be determined if ¢, and ¢, are known. . From the nature of the deflection curve, from 1 to a, F? It eee Fe); ee ee Lp from a to 8, d’y die” A) a) 5 ° ° ° ° ° ° ° ° ° ° . ° ° ° ° (1 2) Mr. J. M. Heppel on the Theory of Continuous Beams. 63 from 6 to 2, d’4 " ee OR a rin tee al a 1 *. from 1 to a, Be), wen 20, F(a) 0, 9. is ; co" ° dat : d 7 =e F(w)—T; EE Se ea, eh utsnd es A essing WRN LD from a to 8, dy ; “= ree ne reed Tommie a MNS Shar Wah a ow CUO WY eB (+O; (15) making v=a in (14) and (15), and transposing, C=c,F,'(a)—e,F,(6)— oo Pack o)—e, GH@EING@) Ue eu oes Gee lo from 6 to 2, | Dw e,Fy(a)+C 3 Pe a oe am making «=6 in (16) and (17), and transposing, C=eF, (a) +e, (F,(0)— F,(a)) —e,F",(3) ; ? ', oa (a) +e, (#,@)—F,@) +¢,(F,(@)—F,2) —T; . (18) *, from 1 to a, _ y=e,F,(w)—Te, no constant; for if v=0, F.w=0,y=0;. . . (19) from a to 6, | y=e,F,(a)e+e,(F,(w)—F,(a)v)—Te+C; . . . » » « « (20) making «=a in (19) and (20), and transposing, | | C=e,(F,a— F,\(a)a) +¢,(F,(a)—F',(a)a) 2. y=e,(F(a)+F,(a(e—a)) +¢,(E(e)— (Ea) +E, (a(w—a)) )—Tes ss (21) from 6 to 2, | y=e,F,'(a)e+e,(F,(6)e—F, (av) +e,(F,(v)—F'(2)")-T#+C; . . . « (22) making ~=6 in (21) and (22), and transposing, | y=c,(E,(a)+F,(@(w—a)) +6, | (F0)+F,'@)\(e—8)) -(F,@+F,@—a)) | +e,| F(w)—(F,(6)+F,(6)(@—6))|—Te «6 wee ee we (88) _ From the way in which this last equation is formed, it is evident that if 64 Mr. J. M. Heppel on the Theory of Continuous Beams. | there were any number of particular values of a to be considered; as a. 5 &e., 7, k, l, the corresponding values of ~ being ¢€,, €,, &C., €,-1) En» it might be written ¢(F\(a) + F(a) (w—a)) y= | +e[ (FG) +F,(2)(e—2)) —( F(a) +F,\(a)(e—a)) | —Tw; (24) tel (RO+E, (eee) —(F,(2) + Fo)(e—2)) | + &e. teal (Ea) +P \(e—2)) — (Ea) +F nV) | +e,| F.(v)—(B,A)+F.(A(w—h)) | ; r—)in((24), y—=()- e,| F(a) + F(@(U—«) | '=5 +e,[ (F, (6) +F,(6)(—8)) — (E,(a) +F, (a)(2—a)) | .. . ee +e,[ (F,(¢)+F, (\@—e)) — (F,(0) + F(2)U—8)) | | + &e. tea[ (Fah) + Fi aAI-2) — (Fa) +F aa) | +e, [F.O-(B.A)+F.(A0—2) | If, now, the formation of the functions F,(a), F,'(a) &c. be examined, it ig evident that this equation may be written T=A¢,+B¢,+C, where A and B are known functions of a, 4, c, &c., and e,, e,, €,, &e., and C is a known function of the same, and p,, p,, pb, &e. If the adjacent span to the left be now considered, it is evident that a precisely similar equation may be obtained, which may be written T’=A'¢,+B'¢,+C ; adding these, and writing ¢ for T+’, which is known as it is the tangent of the small angle which the neutral lines of the two spans would make at the point 1 if relieved from all load, t=(A+A')p, + Bo, + Big. +C+C, which may be written V (go by $3) =0; similarly for the other bearing points in succession, Vo, Pos $,)=0, VC pa» 3» o,)=9, &e., where the number of equations is two less than that of the quantities Mr. J. M. Heppel on the Theory of Continuous Beams. 65 db.» >» &e., so that if two of these are known the rest may be determined. But the first and last are always known, being usually each =0. There- fore they may all be determined. This being so, the bending moment at any point (#.y) may be found from equations (8), (9), (10) and others of the same form; and the deflection may be found from equations (19), (21), (23), and others of the same form, regard being had to the interval of the beam in which the point under examination lies. If, now, we suppose that a= Sees =/, equation (25) reduces to T=; ssl = (FD) similarly, a ANG y = (F.C )) 5 1 i ' : t= Ot pp hil y: EIé=F (D+F, t), writing z for s 3 13 =(5+" Tote ¢,+— ee sole Clearing of fractions and transposing, S(+il')o, +416, +4il'9,=Putilp'+24Elé, . . « (26) an equation which was given by the author in his paper before referred to, and which is nearly identical with the general equation of M. Bresse, and allowing for difference of notation precisely so with that of M. Bélanger. If 2=1 and ¢=0, which is the case of a straight beam of uniform section throughout, 8(7+1')p, +416, +41'9,=Putl?y, 2. 2. + © + 7) which is the equation generally known as the theorem of the three moments. If in equation (25) we put /=a, it becomes eae ee T=ae,(sit 5h gyn) 5 - ee a O8) and for the central deflection equation (19) becomes l D2 Y=a'e,(—F5(+9.)+ 384” H:)} tage aay If we put 6=2a, (= 3a, aa 19 7 »( 43 7 7 f (G+ Ze (Bint Fert et) Wis 13 7 7 13 ) . (30) ta (Fors se alee Gr Int og het 79g hs ) 1 7 a her 1 1] + €, (s+ oe ee (srt zg bet x6) ; VOL. XIx. F 66 Mr. J. M. Heppel on the Theory of Continuous Beams. and central deflection from equation (21), 1 sy Al a 1 ] | Genet (ont pit set) bul anieyo 47 5 hey 31 2 ren (Femt Shet ge )) ) 1 1 1] oi -- b+ Bee H+ 7g bet waa’) If we ia - e— 34, < i—5a- 149 13 iS 13 (Feet one Samer 300" tet ete Tanta gaye) 31 7), 123 31 Tht raph (Sa ug Bin 3 oot a (32 150': . 50 30 YT G00" H 6.4 tap? (Geptit ap mt gy goat apne) 3005 4 Si heel (i+ 150°” \t50'* Go 30° t50™ a00%8 al a pus deflection from equation (23), (; ) & Si of 37 & sgh j 150 7 Gene an ag eT 190" act syn )) 9 Oe 9 469 27 9 ta (ee qe hte geht Se gy tet gyatet gat aye) 1205 7A 31 7 a 7 161 31 . +e, Gene 60 say eae a py 90 Het ek aoe 340 tet Ton ) 1 13 ce Bel ] 7 7 $e (—z9h— ay et (Gont ap 20 Ga hase 12 Temes Go Mat au) As an example of the application of the foregoing method to the purposes of calculation, let the case of the Britannia Bridge be taken, and let the large span be supposed to be divided into five, and the small span into three equal parts, and let the moments of inertia of the sections and loads per unit of length be supposed constant within each part and equal to their mean values. | 0 1 2 A ai a’ A a D C a ix 2 7 1 ] 1 “ Sat Gott Gott ay lst ag act Gy he ) : 31 1GL oy 7 7 te(— S87 ao tt? (ght grotet Tr tet gy et w)) ) (33 Mr. J. M. Heppel on the Theory of Continuous Beams. 67 We have then the following data :— In spans (1 . 2) and (1. 9), a——o2. (jet. c= 3a; a=4a: t= a. a =76°7, 6 =2a, = Ba Hy 1 1 ts 1 pies 1 ais I eel h - o20R 8) 1746m * 1664 °. 1867" / 1 ' ] 1 er O0r?, 2 = 60K, = 7208: ee 331, . = 3°57, 349, == 3°65, i, Seed. iO ae git i232) = Tey 0, E=1440000. In span (2. 1), @= 92. hy C=, =A. l=5a; PE ce ee miso 664. 6B 8 1520 OP TIBI E p,=3°05, p= 3°49, Py= 3°97, =3°31, Ms= 2°89 ; and from symmetry of loading T= = —0:002035. Applying equation (30) and (32) to spans (1 . 0) and (1 . 2) respectively, and eliminating T and T’ by adding them, we obtain 0-1888y, +0:048274,—10481=0; and applying equation 32 to span (2.1), 0-04827¢, +0:087659,— 5420=0, whence ¢,= 416206, 9,=36387. Taking these values of ¢, and ¢,, and applying equation (33) to the calculation of the deflection at the middle of the large span, 0:3 75 t-—4- oimehes: If, now, the values of ¢,, ¢,, and Y be calculated from equations (26) and (19), on the supposition that the moments of inertia of the section and the loads are constant yy ageus each span and equal to their mean values, they are ¢,=47030, 9,=35610, Y=4-62, which are almost identical with the values ascertained by Mr. Pole. If the variation of section alone be considered, the load being taken at its mean value, @,=46382, $,=34465, Y=4:52. It therefore appears that the amount of variation in the section and load which occurs in each span of the Britannia Bridge, when taken strictly into account, produces scarcely any effect on the values of the bending moments and deflections, which are practically the same as those resulting from their mean values considered as constant ; and it may be F2 68 Dr. W. J. M. Rankine on Mr. Heppel’s considered as demonstrated that, for most ordinary cases of large bridges, calculations founded on equation (26) may be confidently relied on. It need scarcely be remarked that these are much more simple and easy than those founded on the more exact but complex equations above given. In smaller bridges, however, the error of the approximate process will be more considerable, and the process above given may be applied with advantage to its correction. In concluding this paper, the author desires to record his thanks to his young friend, Mr. Henry Reilly, for the patience and skill with which he made, in detail, all the intricate calculations of the numerical values of the various functions involved in the above demonstration. “Remarks on Mr. Heppel’s Theory of Continuous Beams.” By W. J. Macquorn Rankine, C.E., LL.D., F.R.S. Received De- cember 22, 1869*. 1. Condensed form of stating the Theory.—The advantages possessed by Mr. Heppel’s method of treating the mathematical problem of the state of stress in a continuous beam will probably cause it to be used both in practice and in scientific study. The manner in which the theory is set forth in Mr. Heppel’s paper is remarkably clear and satisfactory, especially as the several steps of the algebraical investigation correspond closely with the steps of the arithme- tical calculations which will have to be performed in applying the method to practice. Still it appears to me that, for the scientific study of the principles of the method, and for the instruction of students in engineering science, it may be desirable to have those principles expressed in a condensed form ; and with that view I have drawn up the following statement of them, which is virtually not a new investigation, but Mr. Heppel’s investigation abridged. Let (v=0, y=0) and (2=/, y=0) be the coordinates of two adjacent points of support of a continuous beam, w being horizontal. Let y and the vertical forces be positive downwards. At a given point w in the span between those points let p be the load per unit of span, and EI the stiffness of the cross-section, each of ‘which functions may be uniform or variable, continuous or discontinuous. In each of the following double and quadruple definite integrals, let the lower limits be x=0. OH Cx. ‘ fo ol ae Vist ( {rae =F. When the integrations extend over the whole span /, that will be denoted by affixing 1; for example, m,, ,, &c. * Read January 27,1870. See vol. xviii. p. 178. Theory of Continuous Beams. 69 Let —P be the upward shearing-force exerted close to the point of sup- port (v=0), &, the bending moment, and T the tangent of the inclination, positive downwards, at the same point. Then, by the general theory of deflection, we have, at any point of the span J, the following equations :— moment, DO Rae ee ee relia at: emer a2) deflection, eG O MT En tat je ie eto Ss eo) Let ®, be the moment at the further end of the span /, and suppose it given. This gives the following values for the shearing-force P and slope T at the point (w=0):— , Pee mommnnnlene pe | Ce ge ee head and because y,=0, paPicteFo(Z_%) Shy Tw L Consider, now, an adjacent span extending from the point of support (v=0) to a distance (—#=/') in the opposite direction, and let the defi- nite integrals expressed by the formule (1), with their lower limits still at the same point (v=0), be taken for this new span, being distinguished by the suffix —1 instead of 1. Let —T’ be the slope at the point of sup- port (v=0). Then we have for the value of that slope, a es es [!? He l! Add together the equations (5) and (5A), and let = T—T" denote the tangent of the small angle made by the neutral layers of the two spans with each other in order to give imperfect continuity. Then, after clearing fractions, we have the following equation, which expresses the theorem of the three moments in Mr. Heppel’s theory :— 0=6,(¢,0? + date SD) —6,¢l"— Ong : +m,ql?+m_q PF UP—F_ PtP”. f (6) That equation gives a linear relation between the bending moments ®_,,,, ®, at any three consecutive points of support, and certain known functions of known quantities. In a continuous girder of N spans there are N—1 such equations and N—1 unknown moments; for the moments at the end most supports are each=0. The moments at the interme- diate points of support are to be found by elimination; which having been done, the remaining quantities required may be computed for any particular span as follows :—The inclination T at a point of support by equation (5); the shearing force P at the same point by equation (4) ; the deflection y and moment ® at any point in that span by equations (3) and (2). Points of maximum and minimum bending moment are of course Lid found by making —=05 and points of inflection by making &=0. 70 Remarks on Mr. Heppel’s Theory of Continuous Beams. 2. Case of a uniform girder with an indefinite number of equal spans, uniformly loaded ; loads alternately light and heavy.—The supposition just described forms the basis of the formule given in a treatise called ‘A Manual of Civil Engineering,’ page 288; and it therefore seems to me desirable to test those formule by means of Mr. Heppel’s method. The cross-section of the whole girder and the load on a given span being uniform, the definite integrals of the formulee (1) take the following values :— ; 2 2 pe xv 574 ae px mg Py: (7) x? F 9B? 6hi. | 24hln oem The values of those integrals for the complete span are expressed by making v=, The values of m and g are the same for every span. In the values of m and F, the load mw per unit of span has a greater and a less value alter- nately. Let w, be the weight per unit of span of the girder, with its fixed load, w, that of the travelling load (increased, if necessary, to allow for the additional straining effect of motion); then the alternate values of u are p=w,s pw tw, Se) The moments at the points of support are all equal; that is, 6,=, =i. Equation (6) now becomes the following (the common factor /* having been cancelled) :— 0O=—26,n,+F,4+F_,—u; 1 giving for the bending moment at each point of support @ hak Wee 2w +, y 2n, 24 t PEI. 1. . (9) If ¢ be made =0, so that the continuity is perfect, this equation exactly agrees with the formula at page 289 of the treatise just referred to; and the same is the case with the following formule for the shearing-forces and slopes close to a point of support, and for the moments and deflections at other points :— Shearing-force, light load, pastel ; | ve ' wW + w 4 ® ° ° e . ° ( ] 0) Shearing-force, heavy load, P,=— : 1 l — me 3 Slope, light load, Tae Bt at 53 1 3 pat (11) Slope, heavy load, Meer sen la On the Action of Chloride of Zine on Codeia. 71 Moment, light Joad, | | 7] 2 b=, —Pe+m=—; 'EI+ aH —— oo ; | Moment, heavy load, r (12) o = E14 aeee et gl omey bee | | 2 J Central moment, light load, a(« = 5) = FEL ep, ie cE) Central moment, heavy load, o(« =5)=— jee | 2 l 2 J Central deflection, light load, gr w,—20 4 y=Tx—Pq+6, n+ P( with w=5)=5 LeacerTaT laf Central deflection, heavy load, r (14) , : : i\ tl wi,+3w =m) P'o+0n4 F( aoe = us SS OMS 78 y ¢ ain ie yeh yp 8 384EL ee | COMMUNICATIONS RECEIVED SINCE THE END OF THE SEssIon. “ Researches into the Chemical Constitution of the Opium Bases. —Part IV. On the Action of Chloride of Zinc on Codeia.”” By Avueustus Marruressen, F.R.S., Lecturer on Chemistry at St. Bartholomew’s Hospital, and W. Burnsipz, of Christ’s Hos- pital. Received June 23, 1870. On endeavouring to prepare apomorphia by a cheap method, Mr. Mayer and one of us heated morphia with chloride of zinc, to see whether the elements of water could not be abstracted by this reagent (the results of this reaction have not yet been published). Apomorphia having been ob- tained in this manner, it seemed possible that apocodeia, that is codeia minus the elements of water, might be prepared by a similar reaction. On try- ing the experiment a new base was clotiaeel which proved on analysis to be apocodeia. When hydrochlorate of codeia is heated with an excess of a concentrated solution of chloride of zinc, to a temperature varying between 170° and 180° C., for about 15 minutes, the decomposition takes place ; on cooling a yellowish-brown tarry mass separates from the liquid, which on further cooling may be drawn into thin threads, and thus obtained almost free from the excess of the chloride of zinc. ‘This amorphous silk-like mass is almost pure hydrochlorate of apocodeia. ‘To obtain the base in a pure state from this substance, the following method was employed :— The hydrochlorate was dissolved in hot water and precipitated by hy- 72 On the Action of Chloride of Zine on Codeia. _[ Recess, drochloric acid. The liquid containing the precipitated hydrochlorate was allowed to cool, and the precipitate on solidifying was separated from the acid solution. The operation of dissolving and reprecipitating with hydrochloric acid was repeated several times, and lastly the hydrochlorate was dissolved in water, precipitated with carbonate of sodium, and the base extracted with ether. On evaporating the ether-solution the base remained behind as an amorphous, gum-like, reddish mass; this was powdered, dried in a water-bath, and gave on analysis the following results. All combus- tions were made with oxide of copper and oxygen. (1.) 0°3245 gramme of the base, dried at 100° C., gave 0°9150 carbonic acid and 0°2080 water. (II.) 0°3150 gramme of the base gave 0°8860 carbonic acid and 0-1960 water. (III.) 0°4570 gramme of the base, burnt with soda-lime, gave 0°1600 metallic platinum. Found. ee = aS Calculated. (1.) (II.) (IIT.) ‘Ca ee 216 76:87 76°89 76°70 H, Pere 9 6°76 712 6°91 Ne ete 14 4:98 4:97 O, ETRE 32 11°39 281 100°00 The reaction that has therefore taken place is similar to that of hydro- chloric acid on morphia, viz. that the chloride of zinc has abstracted the elements of water, thus :— Morphia. | Apomorphia. C,H, NO; = H0+¢_ No. Codeia. Apocodeia. C,,H,NO, = H,0+C,, H,, NO,. The base itself is soluble in alcohol, ether, and chloroform, but almost insoluble in water, and has not yet been obtained in the crystalline state. The hydrochlorate, obtained by shaking the ether-solution of the pure base with hydrochloric acid, and evaporating the acid solution to dryness, gave the following on analysis :— 0563 gramme of the hydrochlorate gave 0°256 chloride of silver. Calculated. Found. Th Sy eam 282 88:82 (yi 2S Aaa gee eee re 30D 11°18 11°25 a1 7D 100:00 The hydrochlorate cannot be obtained in a crystalline state ; it is easily soluble in water, and is precipitated thence by strong hydrochloric acid. On comparing the actions of different reagents on this base with those obtained with apomorphia (Proc. Roy. Soc. No. 112, 1869, p. 459), they c “4 1870. ] On the Action of Claret on the Human Body. 73 were found to be almost identical, the most marked of the few differences being that the blood-red colour given with nitric acid is much more per- manent than in the similar apomorphia reaction. Between the two bases also a very marked difference exists in respect of stability, apocodeia being far superior in this respect to apomorphia ; in fact it may be precipitated by ammonia or carbonate of sodium, washed and dried, without undergoing a marked change of colour. The hydrochlorates also differ; for that of apomorphia can be easily crystallized, whereas hydrochlorate of apocodeia has only been cbtained in an amorphous state. The preparation of apocodeia is easy and sure, yield- ing avery large product. In this respect it differs materially from apo- morphia, the preparation of which is tedious, and the amount of yield very uncertain, hence the high price of this valuable therapeutical agent. The solutions of the two hydrochlorates also show the same differences that the bases themselves do. In physiological effects also there is a decided difference between the hydrochlorates, that of apomorphia being, as ob- served by Dr. Gee, a very violent emetic, whilst that of apocodeia is, ac- cording to Dr. Legg’s experiments, a mild emetic; it also produces sub- cutaneous abscesses at the place of mjection, which the apomorphia salt does not. It has been shown in Part II. (Proc. Roy. Soc. vol. xvii. p. 460) of these researches, that when codeia is heated with hydrochloric acid it splits up into chloride of methyl, water, and apomorphia. The action of hydriodic acid on narcotine for the elimination of the methyl contained in it is, how- ever, more energetic than that of hydrochloric acid. Therefore it was thought probable that, by means of hydriodic acid, CH, might be ab- stracted alone, as iodide of methyl, from the codeia, leaving the elements of water, and thus forming morphia. On trying the experiment, however, not a trace of iodide of methyl was obtained, but the iodide of a new base, which is at present under ex- amination. The codeia with which the foregoing experiments were made was kindly presented to us by Messrs. M‘Farlan and Co., of Edinburgh, to whose liberality we are already so much indebted. “Experiments on the Action of Red Bordeaux Wine (Claret) on the Human Body.” By E. A. Parkes, M.D., F.R.S., Professor of Hygiene in the Army Medical School, and Count Cyprian Woxtowicz, M.D., Assistant Surgeon, Army Medical Staff. Received July 5, 1870. In the Proceedings of the Royal Society (No. 120) is an account of some experiments with pure alcohol and brandy on a healthy man. This paper is intended as a continuation, with the substitution in the experi- ments of red Bordeaux wine (claret) for alcohol and brandy. The same 74 Messrs. Parkes and Wollowiez on the [ Recess, man was the subject of the experiments, and he was placed on precisely the same diet as is recorded in the former paper. The experiments were continued for 30 days, the man having abstained from any alcoholic beverage for 16 days previously. During the first 10 days, water only was taken at dinner, during the next 10 days red Bor- deaux wine was substituted for the water; 10 fluid ounces (284 cub. centims.) being given on the first 5 days, and 20 fluid ounces (568 cub. centims.) on the last 5 days. The wine was taken at dinner time, at a quarter past 1 o’clock. In the last 10 days water was again given. The wine was a good claret, as it was thought best to use a superior wine ; it was Haut Brion wine of second growth, of the vintage of 1863, and was sold in London at the price of 60s. per dozen. It contained 11 per cent. of alcohol. The free acidity was equal to about 3 grains per ounce of tartaric acid (C,H,O,); the total solids amounted to 21°76 grammes, and the fire-proof salts to 2°359 grammes per litre. Of this amount of salts 2°027 grammes were soluble, and °332 insoluble. In the former, phosphoric acid and chlorine were present in the amounts of *145 and ‘106 gramme per litre respectively; the insoluble salts contained only ‘0175 gramme of phosphoric acid per litre. In the 10 ounces of wine there were therefore only 0°7 grain of phosphoric acid, and 0°46 grain of chlorine. The ash was intensely alkaline, and, when neutralized with standard acid, the alkalinity was found to be equal to 1-679 gramme of tartaric acid (C,H, O,) per litre. Only two circumstances (except the taking of wine) were different in this set of experiments as compared with the former. The first experiments were made in February and March 1870, when the weather was very cold; the present were made in May and June in very hot and dry weather. The only influence we could trace to this altered condition of climate was that the amount of water allowed was in- sufficient, and the man suffered some discomfort from thirst. We could not perceive that any effect was produced on the nitrogenous elimina- tion ; certainly there was no diminution. The other alteration was that the man had gained 4 lbs. in weight, and was still gaining a little when the experiments were commenced ; he con- tinued to do so slowly until the 24th day, when his health began to give way and he lost weight. The experiments included the number of the pulse (taken in the recum- bent position) every 2 hours from 8 a.m. to 10 p.m., tracings of the pulse and respirations, the temperature of the axilla every 2 hours from 6 a.m. to 10 p.m., the temperature of the rectum four times a day (the observa- tions being taken with the same thermometers as on the former occasion), the amounts of nitrogen, phosphoric acid, chlorine and free acidity of the urine, and the weight, and in the two cases the amount of nitrogen in the stools. 1870. | Action of Claret on the Human Body. 75 1. WEIGHT OF THE Bopy (taken at 8 a.m. before breakfast and after emptying the bladder). Weise : | : Weight, | : Weight, || : Weight, Days. Weems in Hilo. | Days. Oa isto: | Days. Ween, in ino. in lbs. in lbs. | in lb grammes. grammes. | grammes. 1. 140 63:6 ||; Ely | 40-5 63:86 || 21. | 140°5 63°86 2. 140 63°6 12. | 1405 63°86 || 22. | 1406 63°91 3. 140 63-6 13. | 1406 63°91 23. | 1406 63°91 4, 140 63°6 14. | 140°6 63°91 24. | 140°6 63°91 5. 140 63°6 15. | 1406 63°91 25. | 140°5 63°86 6. 140°5 63°86 16. | 1406 63°91 26. | 140-4 63°81 é 140-5 63°86 EZ. 3 406 63°91 27. | 1403 63°77 8. 140°5 63°86 18. | 1406 63:91 28. | 140 63 6 <. 140°5 63°86 19. | 140°5 | 63°86 || 29. | 140 63°6 10. 140°5 63°86 20. | 1405 63°86 30. | 140 63:6 Means| 140°25 | 63°75 || ...... 140°55 | 63-863 || ...... 140-35 | 63-79 Owing to the rather larger supply of food and the lessened exercise the weight increased slightly, but remained, on the whole, in tolerable equili- brium until the 24th day, when he became indisposed, and lost weight regularly every day for 4 days. No obvious change in weight was caused by the wine. . 2. Tur CiRCULATION. Pulse before wine (taken in the recumbent position.) Hours. Days. Mean of 8 AM. 110 a.a.| 12 noon.| 2 pt. |4 par. | 6 pn. | 8 par. [10 p.x.| “e days- isiday | 74 | 86 | 74 | 84 | 77 | 84 | 72 | 72 | 77-87 Qnd day..| 67 | 72 | 72 | 82 | 77 | 80 | 75 | 70 | 7437 3rd day ...| 71 | 80 | 72 | 82 | 76 | 82 | 85 | 72 | F775 Miedaye 65. | 75. | 80 | 89 °| 73 1.73 | 78. |-67 175 Sth day ..| 76 | 82 | 72 | 84 | 81 | 82 | 73 | 73 | 77-87 6thday..| 76 | 74 | 77 | 87 | 73 | 76 | 72 | 78 | 760 ith day ..| 72 | 78 | 70 | 90 | 74 | 75 | 90 | 69 | 772 8th day ...| 76 | 7 "3 | 88 | 78 | 8 | 70 | 72 | 76-87 Gteday | 67> 278 | 75) 77° |e | Wes | 7B | WB | 74-9 PGihday| 73 | 80 | 7%, -)879 >, | 74.1. 76.) WS | 67. fe 7a ee ee OO EEE | a The pulse in this man had a daily course of great uniformity, the changes being chiefly dependent on food and in a less degree on exercise. If the last line (the mean of the hours) is read, and it is remembered that breakfast was taken at 8, dinner at 1, and tea at 5, the increase in the number of beats at 10, 2, and 6 o’clock is at once accounted for. It rose after breakfast nearly 7 beats; then fell 4 beats; rose after dinner nearly 10 beats; then fell, but not to its previous standard ; rose after tea 3 beats, and then fell, till at 10 p.m. it was nearly the same as at 8 a.m. The 76 Messrs. Parkes and Wollowicz on the [ Recess, other cause influencing the heart’s beats was exercise ; we kept the exer- cise as uniform as we could, but there were variations, and we could often trace defect or excess of exercise on the next reading of the pulse. The daily mean of the pulse was fairly uniform, the mean of the 10 days being 76°3 beats per minute, the extreme mean daily variation was from 74:2 to 77°87. Pulse during wine; 10 ounces at 1 o'clock during the first 5 days, and 20 ounces during the last 5. Days. HELE, Mean of 8 a.m. |10 a.m.| 12noon. | 2 p.m. |4 p.m.|6 p.m. | 8 p.m. |10 p.m 11th day...) 67 79 76 79 80 87 80 72 17-5 12th day...| 72 71 72 85 82 90 95 82 oie 13th day...| 76 73 70 86 84 89 80 73 788 14th day...) 67 82 83 92 87 89 76 78 81:7 15th day...) 70 81 77 92 88 93 84 76 82°6 16th day...| 77 80 79 76 94. 86 87 76 81:3 17th day...) 74 82 75 93 88 86 80 74 81°5 18th day...) 76 79 75 94 88 91 78 69 80°7 19th day...| 76 82 69 86 96 89 82 78 82:2 20th day...| 68 86 67 85 89 81 79 71 78:2 Means...... 72°3 | 79-1 73°9 86:8 | 876 | 831 | 821) 748 80 5 The wine increased the frequency of the heart’s action by 4% beats every minute during 14 hours in the day, and doubtless also in the re- maining 10, for the pulse at 8 a.m. was still too frequent during the wine period. In the 24 hours there was then an excess in the heart’s action of 6120 beats, or nearly 6 per cent. As the amount of alcohol was 1:1 ounces in the first 5 days, and 2:2 ounces in the other 5, the increase in. the number of the heart’s beats was slightly more than in the days when an equal quantity of pure alcohol was taken. This was partly owing to the continuance of the wine, as the first day’s excess was only 1658 beats, and partly to the fact that whereas in the former series of experiments the mean pulse-beats in the water period were 73°, in this they were 76°3. The man’s heart was evidently rather more excitable in this series than in the former. When the hourly changes are compared with the water period, it is seen that the influence of food is marked as before, but that the wine exag- gerated the effect, and kept the pulse at a greater rate for a longer time. An extract from the Tables will show this. It must be noted that the wine was taken at 1 o’clock, or a little after. Water period. Wine period. Mean number of pulse at 10 a.m. after breakfast... 78°4 Gout, Mean at 2°p.mi after dinner -.............css00rmsee0s 83°7 86:8 Mean at, 4-250 or ( tn. He's. j.ekcdee. bi ladies dees 75°83 87°6 Mean atvOur- Macher wea... «sank ssacdon nce teeneee dade 73:8 88:1 Mica At IS Mtr te or ak tock eae sass nth cesee eee 766 82:1 Nisan at 10 ee Bee ede Abate cane 71:3 749 1870.] Action of Claret on the Human Body. 73 It will be seen, then, that the pulse at 4, 6, and 8 o’clock in the wine period is much above the corresponding numbers in the water period. The effect of the wine is largely perceptible for eight hours, and is traceable during all the observations. The mean of the first five days is 80°34 beats per minute, and of the last five days 80°78 beats. The effect of increasing the wine to 20 ounces is chiefly perceived in the greater acceleration of the pulse at 4 o’clock in the last five days as com- pared with the first five. When 10 ounces were taken, the mean pulse at 4 o'clock was 84°2, or two beats per minute less than at 2 o’clock, where- as in the 20-ounce days the mean pulse at 4 o’clock was four beats above the 2 o’clock rate. Pulse after wine. Days. HOU: Mean of 8 a.m. |10 a.m.| 12 noon.| 2 p.m. | 4.p.m. | 6 p.m. | 8 p.m. [10 p.m. the days: 21st day ...| 68 BG 96 84 90 | 70 69 79°6 22ndday...| 78 84 [2 80 78 83 81 69 73:1 23rd day...| 72 80 74 St 84 78 81 72 78:1 24th day...| 73 79 76 83 79 84 82 74 78°75 25th day...| 70 17 73 17 ie 82 81 78 76:5 26th day...| 69 84 Gl 82 78 84 17 65 V7 27th day...| 70 75° 95 99 89 92 92 80 84:5 28th day...| 70 79 87 86 84 26 84 84 82°5 | 29th day...| 74 82 74 84 84 80 83 79 80° 30th day...) 70 80 70 96 89 79 74 72 78°75 Means...... 71-4 | 806 172 86°7 | 82°3 | 83:8 | 805] 742 | 79°38 The pulse continued high during the whole of this period, the excess being chiefly in the afternoon hours; even 10 days after the wine was left off it had not returned to its proper rate; but this was probably in part owing to indisposition, which will be referred to presently. Sphygmographic observations were taken three times a day ; but as the curves from alcohol were so fully given in the former paper, we have thought. it necessary only to put in nine curves, three before, four during, and two after wine. We have selected 3 o’clock as the hour, so that the influence of food is perceptible in all: the effect of the wine was the same as that of alcohol, though of course in a degree proportional to the amount. We also attempted to determine the ratio of the radial pulse, heart’s action, and respiration by means of Dr. Burdon-Sanderson’s ingenious cardiograph. Unfortunately we did not obtain the instrument in time to determine the curves properly in the period before wine, and we are there- fore not able to give proper comparisons. We could not, however, so far trace any effect on the number or depth of the respirations. 78 Messrs. Parkes and Wollowicz on the [ Recess, | Before claret.—At 3 p.m., 2 hours after dinner. | { ] | ! | : | | | : | ' } aay. of Clavel, > | 8th day P90. | | : | day, PSL, | | | J cay after Claret, - Spm, 8% 6/70. a7% day, PGB. 3. Tue TEMPERATURE OF THE Bopy The temperature was taken both in the axilla and rectum, in order to obtain a control of the observations. The degrees are Fahrenheit. 1870.] Hours. Days. Mean of Giada nee Oe acne lO roorieh) Ol peas | 4 wivpelbGup ante ier Oman oe ars Ist day 97°83 | 98:0 | 98:0 98-0 98-4 | 984 | 984 | 982 | 98-4 98-17 2nd day 974 | 974 | 98-0 97-6 98:4 | 97:3 | 98:0 | 98:8 | 98:0 97°93 ord day 97°38 | 97:0 | 97-4 97-4 98:2 | 98:0 | 97-2 | 986 | 98:4 SET 4th day 972 | 97:0 | 98:4 97:3 97-4 | 97-4 | 97-8 | 980 | 976 97:56 5th day 978 | 97:4 | 97:2 97:0 976 | 976 | 98:0 | 98:0 | 97-6 97°57 6th day 976 | 974 | 97-6 97:8 DOW ORSy OT Ges Oi Ges) 97-2 97°57 7th day 976 | 97°83 | 97-4 97:0 98:0 | 976 | 97°83 | 976 | 97-4 97:57 8th day 978 | 976 | 97-2 97°38 978 | 97:4 | 976 | 98:0 | 97-4 97:62 9th day 97-4 | 97:2 | 98-2 97-6 98:2 | 976 | 98:0 | 97-4 | 98:0 97:73 10th day...| 97-0 97:4 | 98:0 98:0 982 | 97-4 | 97°83 | 988 | 97-4 OTT Means..... 97:54! 97°42 | 97°74) 97:55 | 97-98} 97°70) 97:82) 98:10| 97:74! 97-726 Action of Claret on the Human Body. (a) In the Axilla. The thermometer «was kept in the axilla for 20 minutes or more, while the man was in bed and covered with the clothes. First Period. Temperature of axilla before wine. 79 It will be seen on reading the last line (mean of the hours) that the tem- perature follows the same course as the pulse in being manifestly influenced by food, and rising after breakfast, dinner, and tea. The only exception (and this is perhaps apparent only) is at 8 p.m., when the mean tempera- ture is higher than at 6 p.m. while the pulse is falling ; but this was per- haps accidental, 7. e. a longer series of observations might have given different results; for in three observations the temperature was higher at 6 o'clock, and in three it was equal, while in the other four, when it was highest at 8 o’clock, there were two exceptional high temperatures which augmented the mean amount. at 8 p.m. was lower than at 6. We were unable to see any diurnal change of temperature in this man apart from food ; there was no afternoon or evening rise of temperature, dependent solely on the time of day. The temperature was more uniform than in the experiments in February, Second Period. Temperature of axilla during wine. In the next period the mean temperature Hours. Days Mean of 6 a.m.|8 a.m. |10 a.m.}12noon.|2p.m.|4p.m. 6P.m./8 p.m. |/10 p.m. the days. Iith day...) 97-0 | 97-2, | 97-6 97°8 98:0 | 976 | 97:6 | 97°83 | 97-4 97-dD 12th day...) 97°2 | 97-4 | 97-0 97-4 97:0 | 97:2 | 98:0 | 97°6 | 97-4 97°35 13th day...| 97:0 | 97:2 | 97°6 97-6 98:0 | 97-4 | 98:2 | 97-4 | 97-0 97:48 14th day...| 96:3 | 97:0 | 97°8 97:2 98:0 | 97:3 | 98:4 | 98:0 | 97-6 97-4 15th day...| 97-4 | 976 | 98:0 97-4 98:2 | 98:2 | 98:0 | 98:2 | 97:8 97°85 16th day...| 97-4 | 97°38 | 97-4 98-0 97°83 | 98:0 | 98:0 | 97:6 | 97-6 Vis .| 17th day...) 96°8 | 97:0 | 97-4 97°4 98:0 | 97:3 | 97-4 | 97:0 | 97:0 Dea iechiday:.:| 97:2.) 97:25 | 97-6 98-0 97-3 | 97-6 | 97-4 not|taken | 97:54 19th day...| 97°6 | 98:0 | 97:4 97-4 98:2 | 97-8 | 98:0 | 97-83 | 98:0 97°8 20th day...| 96°38 | 97:0 | 98:0 97:8 98:0 | 974 | 97°83 | 97-6 | 978 97:59 Means..... 97:12| 97°3 | 97:58} 97-60 | 97:90! 97-68 97-88) 97-66 | 97-50| 97:56 80 Messrs. Parkes and Wollowicz on the [ Recess, If the mean temperature at 2, 4, 6, and 8 o’clock, when the wine was acting most on the pulse, are placed side by side, we have,— Temperature. | Hours. Scan ee Water period. Wine period. TAREE eaten HE: 97-98 97-90 TUBING: Ieasectasoesesni 97°70 97°68 ORR IM here eens tase 97:82 97°88 OPPIMEE. Cake re aeas 98°10 97-66 The temperatures of the three first hours are practically identical, and as already said, the rise at 8 o’clock in the water period seems to us acci- dental, 7. e. as dependent on two exceptional high temperatures, which raised the mean amount. In the other 5 hours the mean temperature was four times slightly higher in the water, and once in the wine period. The result of all the observations was that, in the water period of ten days, the mean temperature was 97°°726, and in the wine period was 97°°56, or 0°'166 less, a difference so slight as probably to fall within the limits of unavoidable error. ‘The mean of the first five days, with 10 ounces of wine, was 97°°526; the mean of the last five days, with 20 ounces of wine, was 97°'590, proving that doubling the amount of wine caused no lowering of mean temperature, and probably no rise, as the difference is so slight. We conclude that in health the apparent heat after wine must be owing, as in the case of alcohol and brandy, rather to subjective feel- ings connected with the quickened circulation than with an actual rise of temperature ; but that, on the other hand, wine in the above quantities causes no appreciable lowering of temperature. Third Period. Temperature of Axilla after wine. Hours. Days. Mean of 6 a.m. | 8 a.m. [10 4.m.| 12 noon.| 2 p.m. | 4 P.M. |6 p.m. | 8 p.m. |10 p.m. the days Zist day...| 97-2 | 97-4 | 98:0 98:3 992 | 984 | 986 | 97:6 | 97-6 98 22nd day..| 974 | 97-4 | 982 97°83 98:2 | 97°3 | 98:0 | 97-4 | 97-0 97-6 23rd day...| 97:6 | 976 | 98-0 98-0 98-4 | 98:0 | 97°38 | 98:0 | 98:2 97-9 24th day...| 97°2 | 97-4 | 97-6 97°6 98:2 | 97-6 | 98:0 | 97-6 | 97-0 97-5 25th day...| 97°38 | 98:0 | 97:8 98-4 99-2 | 98:0 | 98:2 | 97-6 | 97-2 98:0 26th day...| 97:0 | 97:0 | 98:2 98-4. 98°83 | 976 | 97:8 | 97-8 | 97-4 SeT 27th day...| 97:0 | 96°83 | 97°8 98-4 99°38 | 98:6 | 98:0 | 97-6 | 97:0 97°8 28th day...| 97-0 | 97:0 | 97:4 98:0 98:6 | 98:2 | 98:0 | 97:8 | 97-6 OTT. 29th day...) 97-2 | 97:0 | 97°6 97°6 98:0 | 976 | 98:0 | 984 | 98:2 97-7 30th day...| 97-4 | 97:6 | 98:0 97-4 98:2 | 97°83 | 98:0 | 97-8 | 97-6 97°8 Means...... 97°28 | 97°32 86] 97:99 | 98:66} 97-96 | 98:04|97-76 | 97-48] 97-86 In this period the diurnal variations were almost identical with the others, and the mean temperature of the whole period was practically the same as that of the first ten days. 1870.] Action of Claret on the Human Body. (6) In the Rectum. Rectum before wine (thermometer inserted for about 3 inches, and kept in for 20 minutes). 10th day... Means 8 A.M. 99:2 Hours. 12 noon.| 4 p.m. 99-6 | 99-95 99:2 99-4 99 99-2 99-4. 99-4. 99-6 99-2 99°8 99-6 99-6 99-2 99-6 99-4 99-4 98-6 99-8 99-4 99:50 | 99°29 Mean of 10: Bea the days. 99°8 99:27 99-2 99°25 99°5 99°37 99°6 99-55 99 99:3 99-6 99°55 99-4 99°45 99:2 99-4 99-0 99 99°8 99°65 99:41} 99°38 8] The mean temperature of the rectum (taken four times a day instead of three, as in the former experiments, and at different hours) was rather higher than the mean of the former experiments, viz. as 99°38 to 99:066. It was also more uniform, both from day to day and hour to hour. If these four hours be accepted as giving the mean temperature of the 24 hours, the rectum temperature was 1°°654 above that in the axilla. Days. 11th day... 12th day... 13th day... 14th day... 15th day... 16th day... 17th day... 18th day... 19th day... 20th day... Means The mean temperature is 0°16 lower. .| 98°86 Rectum during wine. 8 A.M. 98°6 98-4 98-6 98:8 99:4 99°8 98°6 98°8 98°6 99 Hours. 12noon.| 4 p.m. 99-9 99-2 99:4. 99°6 99-4 99°8 99°8 99-2 99:6 99 99-4 99°6 99:6 99°8 99:6 99-2 99:5 99 99-8 99-4 99°60 | 99°38 Mean of teenie the days. 99°6 99°37 99°2 99°15 99 99-2 99 99:2, 99 99°25 99-4 99°55 99 99°25 98 98°9 98°4 98°87 99°8 99°95 99:04} 99°22 It is curious that this is almost precisely the same change as in the case of the axillary temperature; yet it is probably an accidental coincidence. The 4 p.m. temperature, which ought to show the effect of wine, is slightly higher (0°09) than in the first period; the 10 p.m. and 8 a.m. temperatures are lower by nearly 0°°3, and the 12 o’clock temperature is higher by 0° 1. The differences are thus slight, and in contrary directions, so that no de- cided influence, one way or the other, can, we think, be ascribed to the wine. VOL, XIX. 82 Messrs. Parkes and Wollowicz on the [ Recess, Rectum after wine. Hours. Days. Mean of the days. 8 a.m. | 12noon.|4 p.m. |10 pa. 2lst day ...| 99:8 99:9 99-4 | 99-2 99:57 22nd day ..| 99:0 99°6 99°38 | 99:0 99°35 23rd day...| 99:0 99°5 99:2 99°6 99°32 24th day...| 99:2 99-4 99:25 n99:0 99:2 25th day...) 99°6 99-4 99-4) 99-2 99:4 26th day...| 98°8 99-2 99-4 | 99:0 99-1 27th day...| 98°8 99:2 OO-2milnoo = 99°15 28th day...) 99-0 99-4 99°6 | 99-4 99°35 29th day...) 99-6 99-2 99:0 | 99°6 99°35 30th day...) 98°8 99:8 99°6 | 99-4 99-4 —_——— | | Means...... 99:16| 99-46 | 99°38) 99:28) 99°32 The temperatures are almost precisely the same as in the first period. The 4 o’clock temperature is identical with that of the wine-period. 4, ACTION ON THE URINE. Elimination of water by the kidneys. Twenty-eight fluid ounces were taken as drink, and the water in the So-called solid food made the total daily ingress of water 724 fluid ounces, or 2059 cub. centims. The following are the means of the three periods :— Amount of water taken daily in solid food and as Mean amount of urine passed in 24 hours. Ist period (water) ....cccccscsese+- 2059 ¢.¢. 1210 ce. 2nd period (wine) ................+. 2010 c.e. 14S rere: SLanperiods(water)), ca. ..cuecaen de: 2059 c.c. Ti baxere As 49 cub. centims. less water were taken in the wine-period, the amount of urine ought perhaps to be increased by this amount, and this would make it only 13 cub. centims. less than the first period, It may be concluded that 10 and 20 ounces of light wine (containing I'l and 22 ounces of alcohol), when substituted for water, had no diu- retic effect. The amount of alcohol to act as a diuretic was perhaps too small, as in the former series with the larger quantities of alcohol there was certainly some increased flow of urinary water. Elimination of nitrogen by the kidneys. The same amount of food being given as in the previous experiments, the amount of nitrogen passing into the body was 17% or 173 grammes, or probably a little more. The whole of this passed by the urine and bowels, so thatin this respect the difference in the temperature of the air had no effect. In other words, although the weather was so hot, there was no evidence of urea escaping by the skin. 1870. ] Action of Claret on the Human Body. 83 The substances precipitated by Liebig’s mercuric nitrate were as usual termed urea, and the nitrogen was calculated from this. It was also for the sake of control determined by soda-lime. Nitrogen before claret. Nitrogen Nitrogen Days. Urea. calculated from by urea. soda-lime. grammes. grammes. grammes. USEC Aye oh 8 se 30°299 14-139 14-211 DMG GAY seh. <0: 33°343 15-560 16°555 BUG Gaye cuenta. 31094 14-487 14-9179 AGL aver feo 5 :5 2°352 5524 1-756 Patina Glaiyeny: =. 2% 2:450 6°658 1:940 Stn day sc. 2.00: 2°333 5-403 1:486 NOthidair.. 2.050: 2:442 5-793 2-709 WZchidaiy ves. s< se: 2-577 5°999 2-972 USthi dayne. shace 2-132 6°498 2:948 LUST C BW opecarns 1:942 © 7:045 2°182 Ath day---...... 1-881 §:235 2°503 Ast Clayrss4.cts 2:678 6-276 2°784 22nd day ...... 2°405 7-422 2-457 23rd day ...... 2°265 6:543 2-782 24th day......... 2°453 7494 2°469 2th day.aec2i. 2-138 TNS 2-013 26th. day......... 2286 10°763 1-968 27th day......... 2°798 7-074 3°339 28th day......... 3040 7-025 2°745 AGA Gaye .ccss! 2°7(22, 6:170 2°308 80th day......... 1182 5-286 1-489 The mean quantities are as follows :— oe Chlorine. Free acidity. First period (before wine)........ccsseeeceeess 2296 7°708 1-955 Second period (during wine) ............... 2:247 ~ 6202 2-221 Third period (after wine).........0cccesse+s0s 2396 7-176 2-435 Red Bordeaux wine, in quantities of 10 and 20 ounces per diem, did not 86 Messrs. Parkes and Wollowicz on the [ Recess, affect the excretion of phosphoric acid. The effect on the chlorine is uncertain, as that ingredient bas such a wide rangeof variation. It is, however, interesting to note that the mean daily excretion of the whole thirty days is almost precisely the same as the mean daily excretion of the twenty-five days in the previous series (viz. 7028 grammes as against 6°915 grammes), and this proves the equality of the diet. The acidity of the urine was increased during the wine-period, and this continued afterwards. It may be observed that the mean free acidity of the former experiments was almost precisely the same as in these experi- ments during the water-period (viz. 1°974 as against 1-955 gramme), and was very nearly the same in the alcoholic as in the wine-period (viz. 2°342 as against 2°221). It seems fair to conclude that the free acidity was really increased, and that the increase continued subsequently. 5. Tue Auvine DIscHARGEs. Weight of Stools. Days. | Ounces. | Grammes.|} Days. | Ounces. |Grammes.|| Days. | Ounces. | Grammes. ea SD ll. | 4:25 21. | 33 246 IA er Ranss 22. ome face. 13. 5°75 23. | 8:33 4h 14 8-1 24. Da ee 15 4 25. | 6°75 6. | 4:25 16 4 26. 4:5 ian aU AVY Sess: MG 32) D oh ine acee 1823) 97-25 28. | 3:25 9. 3°75 19. 3°75 29. LOD OF 20 od 30. | 7 Means| 4:°147 | 117-56° || ...... 4-060 Uae ai cone 3°788 107-4 The nitrogen was determined twice, viz. on the 10th day (last day be- fore wine), and on the 19th day (last day but one of wine). Unfortunately there had been some constipation before the 10th day, and the stool was unusually copious and less watery ; it represented, in fact, some accumula- tion, and therefore the nitrogen ought to be credited in part to the previous days. The following Table gives the results :— Percentage. Amount of Days. Weight of stool. | ————>——_______ | nlitrogenminga Solids. | Water. |Nitrogen. hours. ounces. | grammes. grammes. 10th day (water drinking) ...... 7:97 226:0 | 32405 | 67:595 | 1:294 2925 19th day (wine drinking) ...... 3°75 1063 | 21:820} 78180 | 1:207 1-283 1870. ] Action of Claret on the Human Body. 87 Looking to the mean weight of all the stools, to the particular cireum- stances of the 10th day’s stool, and the very nearly equal percentage of nitrogen on the 10th and 19th days, it may be concluded that the wine did not affect the intestinal discharges either as regards quantity or nitrogen. 6. Tur ELIMINATION OF ALCOHOL. As in the former series, the numerous experiments we had to perform prevented us from thoroughly investigating this difficult problem. We tested the appearance of alcohol in the excreta by the bichromate-of-potas- sium test as before. The general results were as follows :— Elimination by the breath. In the first period the bichromate test was not tried on the first day ; it was very slightly changed in colour on the 2nd, 3rd, and 4th days, when the breath was blown through the test for 15 minutes about 2 o'clock. On the remaining Sth, 6th, 7th, 8th, 9th, and 10th days, no change was produced. On the Ist day of wine after dinner, the colour became green in eight minutes, on the 2nd day in six minutes, and subse- quently a little sooner. On the 16th and subsequent days (when the wine was doubled) the change was much greater. In the evening, except in one or two cases, no change was produced. On the 21st day (1st day after wine) and subsequent days there was no alteration. The breath was condensed by a freezing-mixture on the 9th day about 4 o'clock; about 4 cub. centim. was collected ; it was tested for alcohol by the Iodoform test, but none was found; it was unfortunately not examined by the bichromate test. On the 20th day (20 ounces of wine) the breath was again condensed ; it gave an immediate marked green reaction with the bichromate test. On the 22nd day (the 2nd after the wine) it was again condensed, and gave still an immediate reaction, though not so marked as on the 20th day ; so that two days after the wine was left off, some was passing off by the lungs, though it was not detected by merely breathing through the test. On the 25th and 28th days, when the breath was again condensed, no effect was produced on the bichromate test. Elimination by the skin. In the former series of experiments, when the perspiration was obtained by putting the arm in an hermetically sealed glass jar, no effect was pro- duced in the bichromate test by the sweat before alcohol had been taken. But on this occasion, when 12 cub. centims. of perspiration were collected in four hours on the 5th day, the bichromate test was at once made green. No alcohol was detected by the Iodoform test, but we are not certain if this can be relied upon. This was on the 17th May, and no alcoholic liquid had been taken since the 25th April. ee ee. tS oh lhc ee 88 Messrs. Parkes and Wollowicz on the [Recess, It seemed improbable that alcohol, taken so long before, could be still passing off; and if not, then the perspiration may at times contain some non-alcoholic substance capable of reducing the bichromate. The perspiration of the arm was condensed on the 10th day (before wine), on the 19th day (during wine), and on the 26th, 28th, and 30th days (after wine). In all cases an extremely marked green reaction was at once given. We conclude, therefore, that fresh experiments are necessary with re- gard to the correctness of the bichromate test, when applied to the con- densed perspiration. Elimination by the kidneys. The examination was conducted in the same way as on the former occa- sion, the urine being first distilled, the distillate tested with the bichro- mate test, and if no reaction was given redistilled. The following Table gives the results :— Reaction with bichromate. Days. Ist distillate. 2nd distillate. Gthiday GVALEr)........2...02: A very slight and scarcely) A very slight change, scarcely perceptible change. to be affirmed*. 15th day (wine, 10 oz.) ... No change. No change*. 16th day (wine, 20 oz.) ... No change. No change*. 18th day (wine, 20 oz.) ... No change. Slight. 20th day (wine, 20 oz.) ... Slight. Marked. 22nd day (water) ..<.....-..: None. None. Diba day (Water) ......2:..-- None. None. We conclude from this Table that when 10 ounces of wine (containing 1-1 ounce of absolute alcohol) were taken, no alcohol passed inte the urine. On the 16th day, when 20-ounces (=2°2 ounces of absolute alcohol) were taken, none was found in the urine; the next day no examination was made, but on the 18th day alcohol was detected, and two days later the reaction was marked. Two days after the wine was left off no alcohol was found. Therefore, when this man took 2 ounces of absolute alcohol day after day, some of it was eliminated by the urine. When he took only 1 ounce, none was eliminated during the space of five days. If, as has been sur- mised by Dr. Anstie, the appearance of alcohol in the urine indicates that there is an excess in the body, it seems clear that this man cannot take much more than 1 ounce without the urine giving evidence of it, and thereby proving excess. It soon disappeared from the urine, certainly on the 2nd day (the first day’s urine was not examined), whereas, on the former occasion, when a much larger quantity had been taken, it could be detected five days after it had been discontinued. * Tested also with the Iodoform test. No reaction. 1870. ] Action of Claret on the Human Body. 89 Llimination by the bowels. . No experiments were made. GENERAL CONCLUSIONS, 1. The general results of these experiments are in all respects identical with the experiments on alcohol and brandy, that is to say, there was a marked effect on the heart, coinciding tolerably well in amount with the effect produced by pure alcohol in the former experiments; there was no unequivocal alteration of temperature in the axilla or rectum, no alteration in the elimination of nitrogen, for the increase in the last period cannot be eredited to the direct effect of the wine; no alteration in the phosphoric acid of the urine; some augmentation of the free acidity of the urine ; no alteration of the alvine discharges. In other words, claret-wine in the above quantities cannot so far be distinguished in its effect from pure alcohol. Its most marked effect, the increase of the heart’s action, must be ascribed to the alcohol, in great measure, though the ethers may play some slight part. But it would be going too far to assert that the dietetic effects of red Bordeaux wine and of dilute alcohol are identical. The difference between them must probably be sought in their effects on primary digestion and assimilation, delicate and subtle influences which experiments like those recorded in the paper do not touch. ‘The infiuence of the sugar, of the salts, and of the acidity must also be appreciated by other methods. The man himself affirmed that the wine agreed with him better than the alcohol or brandy, but the large quantity he took of these last fluids vitiates the comparison. These experiments on wine enabled us to define somewhat better than the previous trials what might be considered moderation for this man. The 10 ounces of wine, containing about | fluid ounce of pure alcohol, did not cause the least unpleasant feeling of heat or flushing. The 20 ounces (containing almost 2 fluid ounces of alcoho!) were manifestly too much. He felt hot and uncomfortable, was flushed, the face was somewhat congested, and he was a little drowsy. Moreover, as already mentioned, alcohol then began to appear in the urine. Therefore he ought certainly not to take much more than 1 fluid ounce of absolute alcohol in 24 hours. With regard to the propriety of this healthy man taking any alcohol, we have no hesitation in saying he would be better without it. His heart naturally acts quickly and strongly enough ; alcohol increases its action too much, and might lead on to alteration in its condition, or to injury of vessels, if any degeneration were to take place in them. ‘This man had gone through the Abyssinian campaign, and stated that when the force was without rum, owing to deficiency of transport beyond Antalo, he had in no way felt the want of the stimulant, though some of his comrades did. This seems to confirm our opinion, that alcohol for him is not a necessity, and indeed is not desirable. . VOL, XIX. H 90 Dr. W. J. M. Rankine on the [ Recess, “On the Mathematical Theory of Combined Streams.” By W. J. Macquorn Kankine, C.K., LU.D., F.R.SS. Lond. and Edin. Received Sept. 10, 1870. 1. Object of this Investigation.—The principles of the action of com- bined streams were to a certain extent investigated by Venturi, and stated in his essay ‘Sur la Communication latérale du Mouvement dans les Fluides’ (Paris, 1798). The principle of the conservation of momentum, so far as I know, was first explicitly applied to combined streams by Mr. William Froude, F.R.S., in a paper on Giffard’s Injector, read to the British Association at Oxford, in i860, and published in the Transactions of the Sections, p. 211. Various other authors have treated the same problem by different methods, based virtually on the same principle. A very complete and precise investigation of the theory of combined streams, in every case in which two streams only are combined, is con- tained in Professor Zeuner’s treatise ‘ Das Locomotivenblasrohr”’ (Ziirich, 1863), The theoretical conclusions are tested by comparison with experi- ment, and applied to practical questions, especially those relating to the apparatus from which the treatise takes its name. The object of the present investigation is to apply similar principles to the combination of any number of streams; and the demonstration of the fundamental dynamic equation differs from that given by Zeuner in method, though not in prin- ciple, being effected at one operation by the direct application of the prin- ciple of the equality of impulse and momentum, instead of by the con- sideration of the loss of energy that takes place during the combination of the streams. 2. Terms and Notation used, and Suppositions made.—The several streams which are combined will be called before their junction, the com- ponent streams; the stream formed by their combination will be called the resultant stream. ‘The passages through which the component and resultant streams flow will be called respectively the supply-tubes and the discharge-tube. The combination of the streams will be supposed to take place in a short cylindrical chamber, with its axis parallel to the direction of flow, which will be called the junetion-chamber. At one end of the junction-chamber are the outlets of the supply-tubes, which will be called the nozzles; at the other end, the inlet of the dis- charge-tube, which will be called the throat. It will be supposed, further, that the supply-tubes are so formed as to direct the component streams at the nozzles, so that they shall all flow sensibly parallel to each other and to the resultant stream. The principal symbols used are as follows: for any one of the component streams :— a, area of nozzle ; v, velocity of flow at nozzle ; S,, bulkiness, or reciprocal of density at nozzle. The several component streams may be distinguished from each other, when required, by suffixes; as 1, 2, 3, &c. 1870. | Mathematical Theory of Combined Streams, 91 For the resultant stream : A, area of throat ; V, velocity of flow at throat ; S,, bulkiness, or reciprocal of density at throat. We tensities of pressure, in absolute units on the unit of area: Pp» at the nozzle end of junction-chamber ; P,, at the throat. (These may be converted into wnits of weight on the unit of area, by dividing by 4). The flow of each stream is supposed to be steady. The fluids may be either liquid, vaporous, gaseous, or mixed. 3. Equation of Continuity.—The mass of fiuid that enters the junction- ‘ 6 O c A : av ; chamber through a given nozzle in a unit of time is pa The mass T 0 , SEN discharged in the same time at the throat is “g_- The flow being steady, 0 the following equation must at every instant be fulfilled: AV av S a . . 3 . ° e . (1) 0 0 If S, and the several values of s, are given, that equation gives the velo- city a the resultant stream in ae of those of the component streams ; Viz. 3; VapE Se eee ee es (IA) If all the fluids are liquids, each of sensibly invariable bulkiness, we have also AV=3. av; that is, the volume of flow of the resultant stream is equal to the ageregate of the volumes of flow of the component streams ; but if any or all of the streams are vaporous or gaseous, the values of s, will depend upon that of p,, and the value of 8, upon that of P,, and upon the changes of bulkiness of the fluids which may take place in the junc- tion-chamber, through change of PTIpEEADEC) change of condition, or chemical action. In any case S, may be regarded as a given fuiction of P,, and of the : au, mutual proportions of the several values of ae other words, of the 0 ingredients in the resultant stream. 4. Dynamical Equation.—The aggregate momentum of the mass of fluid that enters the junction-chamber through the nozzles in a unit of 2 time is 2. =. The momentum of the equal mass which leaves the junc- , | 9 a tion-chamber through the throat in the same time is 5 0 The forward impulse exerted in a unit of time upon the mass of fluid in the junction-chamber by the pressure at the nozzle end of the chamber is p,A. The backward impulse exerted in the same time on the same mass by the pressure at the throat-end of the chamber is P,A. By the 92 Dr. W. J. M. Rankine on the [ Recess, second law of motion, the difference between those impulses is equal to the change of momentum produced ; that is to say, es AV? A(P,—p,)=3 =2{@0-v)}; le or dividing both sides by A, . eee av ] P,— =32 _f=3{2 —V) i. Pho ge Va ee oP 0 And this is the general dynamical equation of the combination of any number of streams of any fluids. If the preceding equation, as applied to a combination of two streams only, be compared with the equation not numbered, which immediately precedes equation 60 in Zeuner’s treatise, it will be seen that they are virtually identical, although different in form, and Hee by different methods. 5. Loss of Energy at Junction.—If a given mass of any fluid at the bulkiness s and pressure p is contained in a reservoir, from which it is capable of being expelled by the inward motion of a piston loaded with an external force equivalent to the pressure, it is known that the potential energy of the mass of fluid and of the piston relatively to a point at the level of the centre of mass of the fluid is expressed by multiplying the mass by - sdp, the relation between s and p being that which is called 0 adiabatic ; that is to say, such that no heat is received or given out by the fluid. Hence the loss of energy in the junction-chamber in each unit of time is given by the following expression :— 2 {25+ ap) | —5 BY (N. a sa), weer of which the first, or positive term, we the aggregate energy, actual and potential, of the component streams as they enter the junction-cham- ber; and the second, or negative term, expresses the total energy, actual and potential, of the resultant stream as it leaves that chamber. That lost energy takes the form partly of visible eddies and partly of invisible molecular motions—that is, of heat. The integral expressing the aggregate potential energy of the component streams may be put in the following form :— 0 € avs 0 So If no change of total bulkiness arises from the mixture of the component streams, the volume occupied by a given mass of the mixture is simply the sum of the volumes of its ingredients; so that we have AVE 900800 9. a Ss 8, 0 Se a 1870. ] Mathematical Theory of Combined Streams. 93 and the expression for the loss of energy becomes aot_AV?_AV("* gp (3C) Geass 8 When the fluids are all liquids, whose compressibility may be neglected, we have Pe SdP=S,(P,—p,); and substituting for the difference of Po pressures its value, according to equation (2), the following expression is found for the loss of energy at the junction, ef oir. OO ee) So 2 that is to say, in the case of liquids all the energy due to the several velo- cities (v—V) of the component streams relatively to the resultant stream is lost. When the expression (3 D) is reduced to a single term, it becomes the well-known value of the loss of energy of a single stream of liquid at a sudden enlargement in a tube. 6. Efficiency of Combined Streams.—The efficiency of a set of combined streams may be defined as the fraction expressing the ratio borne by the total energy of the resultant stream after the combination to the aggregate energy of the component streams before the combination. It is expressed as follows :— =P AV {V? 0 aense iG SS Sd : { : +f P| lef) 7. General Problem of Combined Streams.—In most cases the problem of combined streams takes one or other of the two following forms. In each of the two forms the areas of the nozzles a,, a,, &c. are given, and also the area of the throat, A. ; First Form.—The quantities given, besides the before-mentioned areas, are the pressure at the nozzles, p,, and the velocities of the component streams, v,, &c. The functional values given are those of ,, ,, S995 &c., in (4) terms of p,, and of S, in terms of P,, = “ey &c. Those functional ; 0? 1 0? 2 values are to be substituted in the equations (1) and (2); and the solution of these equations will give the numerical values of V and of P,. In the case of liquids of sensibly constant bulkiness, s,, ,, &c., and S, are quan- tities sensibly independent of p, and P,; and then equations (1) and (2) can be separately solved without elimination, giving respectively V and P,. Second Form.—Kach of the component streams flows through a passage whose factor of resistance, f, is given, from a separate reservoir in which the pressure p and the elevation 2 of the surface above the junction- chamber are given. The resultant stream flows through a passage whose VOL. XIX, I 94 On the Mathematical Theory of Combined Streams. [Nov.17, factor of resistance, F, is given, into a reservoir in which the pressure P and the elevation Z of the surface above the junction-chamber are given. These, together with the areas A, a,, a,, &c., are the quantities given. The functional values given are those of the bulkiness, s,,,, s,,,, &c., and S,, as before; also the following values of the velocities, according to well- known principles in hydrodynamics ; for any component stream, iL 2ge+2f sdp A e) Po 5 . e ° e e (5) Ls ay and for the resultant stream, 2gZ+2 SdP ee lc as ; 1+F The functional values given are to be substituted in equations (1) and (2), whose solution will then give the numerical values of p, and P,; and from these and the other data the numerical values of », &c. and of V may be calculated. November 17, 1870. General Sir EDWARD SABINE, K.C.B., President, in the Chair. In pursuance of the Statutes, notice of the ensuing Anniversary Meeting was given from the Chair. General Boileau, Mr. Busk, Mr. David Forbes, Sir John Lubbock, and Mr. Mivart, having been nominated by the President, were elected by ballot Auditors of the Treasurer’s accounts on the part of the Society. Mr. Andrew Noble, Capt. Sherard Osborn, and Mr. George Frederic Verdon were admitted into the Society. Anders Jéus Angstrom, of Upsala, and Joseph Antoine Ferdinand Plateau, of Ghent, were proposed for election as Foreign Members, and notice was given from the Chair that these gentlemen would be ballotted for at the next Meeting. The Presents received were laid on the table, and thanks ordered for them. | The following communications were read :— I, “ Researches into the Chemical Constitution of the Opium Bases. —Part IV. On the Action of Chloride of Zine on Codeia.” By Aveustus Martuizssen, F.R.S., Lecturer on Chemistry at St. Bartholomew’s Hospital, and W. Burnsipz, of Christ’s Hos- pital. Received June 23, 1870. (See page 71.) . 1870. ] Prof. Owen on the Fossil Mammals of Australia. 95 IJ. “ Experiments on the Action of Red Bordeaux Wine (Claret) on the Human Body.” By H. A. Parxss, M.D., F.R.S., Professor of Hygiene in the Army Medical School, and Count Cyprian Woxtowicz, M.D., Assistant Surgeon, Army Medical Staff. Received July 5, 1870. (See page 73.) Ill. “On the Mathematical Theory of Combined Streams.” By W. J. Macquorn Rankine, C.E., LL.D., F.R.SS. Lond. and Edinb. Received Sept. 10, 1870. (See page 90.) IV. “On the Fossil Mammals of Australia.—Part IV. Dentition and Mandible of Thylacoleo Carnifex, with Remarks on the Argument for its Herbivority.” By Prof. Owrn, F.R.S. &c. Received September 27, 1870. (Abstract. ) In this paper the author, referring in the Introductory Section ($ 1) to objections published to his former restorations and inferences as to the function of the dentition of Thylacoleo, proceeds to give descriptions, with figures, of ($ 2) an upper jaw and maxillary teeth, and (§ 3) of a portion of the mandible with mandibular teeth, from tertiary deposits at Gowrie Creek, Queensland, presented to the British Museum by Sir Daniel Cooper, Bart. He then describes certain specimens and photographs of maxillary teeth (§ 4), and of mandibular teeth (§ 5) of the Thylacoleo, subsequently ob- tained by Prof. A. M. Thomson, of Sydney, and Gerard Krefft, Esq., Cu- rator of the Museum of Natural History, Sydney, New South Wales, from caves in Wellington valley, for the exploration of which a grant had been voted by the Local Legislature of New South Wales. Section 6 is given to a description of the specimen in the British Museum, and a cast in the Museum at Sydney of an entire inferior in- cisor, transmitted, with the photograph above mentioned, to the author. The guiding principle in inferring function from form of teeth is next de- fined ($ 7), and the author proceeds to discuss the objection from the loca- tion of laniaries in§ 8. The dentitions of Thylacoleo and of Phascolarctos are compared in § 9; andthe results contrasted with those of the advocates of the herbivority of both genera, which were illustrated by the figures 2&4 in the ‘Quarterly Journal of the Geological Society,’ vol. xxiv. pp. 312, 313 (1868). In § 10 the deductions from the mandibular characters of carnivorous and herbivorous marsupials are tested, and those characters illustrated by descriptions and figures of the lower jaw in Thylacoleo, Cheiromys, Pla- giaulax, Thylacinus, Sarcophilus, Phascolarctos, and Hypsiprymnus. The testimony to the native food of the Aye-aye is sifted in§ 11, and the r2 96 Prof. Owen on the Fossil Mammals of Australia. [Nov. 17, bearing of the characters of its mandible and dentition on the question of the carnivority or herbivority of Thylacoleo is weighed. A like comparison and physiological consideration are applied to the mandibular characters of Thylacoleo, Plagiaulax, and the true Rodeutia in § 12; and the author next ($13) proceeds to the consideration of the form, structure, and growth of the large incisors in the Diprodont paucidentate Marsupials, and in the lemurine and lissencephalous Rodents. To the affirmation of “the obviously phytophagous type of the incisors of Thylacoleo and Plagiaulax,” the author, referring to the descriptions and figures of those teeth in the preceding part of his paper, enters upon a consideration of the relations of their differences from those teeth in the truly phyto- phagous Marsupials and Placentals to interrupted and continuous applica- tion of teeth ($ 14). The alleged adaptability of the carnassials in Thyla- coleo to reduction of vegetable food leads next to a consideration of the work of the molar machinery in known existing Herbivora (§ 15). In section 16 the place, and especially the family relations, of the Thy- lacoleo in the Marsupial order are considered. Instances of existing di- protodonts subsisting on animal food, and of existing polyprotodonts on vegetable food, are adduced ; and, after comparisons with the genera Ma- cropus, Halmaturus, Lagorchestes, Heteropus, Petrogale, Osphranter, Dendrolagus, Hypsiprymnus, Bettongia, Potorous, Dorcopsis, Cuscus, Phascolarctos, Phalangista, Hepoona, Dactylopsila, Petaurus, Belideus, Acrobata, Petaurista, Dromicia, Tarsipes, the author is led to assign Plagiaulax and Thylacoleo to a distinct family of Diprotodont Marsupials under the name “ Paucidentata,’’ in reference to the reduction of the molar teeth to one on each side of the upper jaw, and two on each side of the lower jaw. He then (in § 17) discusses the reality and value of the indica- tions of tendency from the “ general to the particular’’ in the dentition of the mesozoic and neozcic Paucidentate Marsupials. The objections to the predaceous nature of Thylacoleo and Plagiaulax from their alleged feeble- ness and dwarfishness are discussed in § 18. The groundson which John Hunter was led to refer the molar of Mastodon ohioticus to either a carni- vorous or a mixed-feeding animal, and those on which the author refers the dentition and skull of T’hylacoleo to a carnivorous species, are contrasted, and the nature of a disparaging comparison is exposed in § 19. The author concludes by a description of certain unequal phalanges, which supported a strong claw, bound close by a basal bony sheath, as in _the Lion, obtained from the breccia-caves of Wellington valley, and for which, among the fossils thence exhumed, there is not, at present, any other claimant save Zhylacoleo. = 1870. | On the Indian Pendulum-observations. 97 November 24, 1870. ‘General Sir EDWARD SABINE, K.C.B., President, in the Chair. In pursuance of the Statutes, notice was given from the Chair of the ensuing Anniversary Meeting, and the list of Officers and Council proposed for election was read as follows :— President.—General Sir Edward Sabine, R.A., K.C.B., D.C.L., LL.D. Treasurer.—William Spottiswoode, Esq., M.A. ( William Sharpey, M.D., LL.D. Secretaries.— i George Gabriel Stokes, Esq., M.A., D.C.L., LL.D. Foreign Secretary.—Prof. William Hallowes Miller, M.A., LL.D. Other Members of the Council_—George Burrows, M.D.; Heinrich Debus, Hsq., Ph.D. ; Prof. Peter Martin Duncan, M.B.; Sir Philip de M. Grey-Egerton, Bart.; Prof. George Carey Foster, B.A.; Francis Galton, Esq. ; John Peter Gassiot, Esq., D.C.L.; Joseph Dalton Hooker, C.B., M.D. William Huggins, Esq.,D.C.L., LL.D.; Prof. George M. Zumphry, M.D.; John Gwyn Jeffreys, Esq.; Sir John Lubbock, Bart.; Charles William Siemens, Esq., D.C.L.; Prof. Henry J. Stephen Smith, M.A. ; Prof. John Tyndall, LL.D.; Prof. Alexander W. Williamson, Ph.D. Pursuant to notice given at the last Meeting, Sir John Rennie proposed and General Boileau seconded His Grace the Duke of Sutherland for elec- tion and immediate ballot. The ballot having been taken, the Duke of Sutherland was declared duly elected. Pursuant to notice given at the last Meeting, Anders Jons Angstrom, of - Upsala, and Joseph Antoine Ferdinand Plateau, of Ghent, were ballotted for and elected Foreign Members of the Society. The following communications were read. :— I. “Communication from the Secretary of State for India relative to Pendulum Observations now in progress in India in connexion with the Great Trigonometrical Survey under the Superinten- dence of Colonel J. T. Warxer, R.E., F.R.S.” Read by order of the President and Council. India Office, S.W., 3rd October, 1870. S1tr,—I am directed by the Secretary of State for India to transmit to you, for the information of the President and Council of the Royal Society, the enclosed copy of a letter from Colonel Walker, the Superintendent of the Great Trigonometrical Survey of India, on the pendulum-observations that have been carried on since 1865 by Captain Basevi, together with a note, tabulated results, and a Map of India showing the pendulum-stations, The Duke of Argyll will be obliged if, in accordance with Colonel Walker’s wish, the President and Council would be so good as to furnish 98 On the Indian Pendulum-observations. [Noy. 24, His Grace with any suggestions that may occur to them with reference to supplementary measures that may appear necessary in order to complete the operations which were commenced at the suggestion of General Sabine, and with the concurrence of the Council. I am, Sir, Your obedient Servant, J. Cosmo MELVILL. The Secretary to the Royal Society. Enclosure No. |. Government of India, Home Department—Geogr phen To His Grace the Right Honourable the Duke of Argyll, Kt., Her Majesty’s Secretary of State for India. Simla, the 26th of August, 1870. My Lorp Duxe,—Referring to Sir Charles Wood’s despatch in the Military Department No. 271, dated the 23rd of August, 1864, authorizing the carrying out of certain pendulum experiments in connexion with the operations of the Great Trigonometrical Survey of India, at the re- commendation of the President and Council of the Royal Society, we have the honour to transmit, for your Grace’s information, copy of a letter from Colonel Walker, No. 49-793, dated the 11th instant, together with its enclosures, showing what has been done and what remains to be done to complete the original programme. 2. With reference to the last paragraph of Colonel Walker’s letter, we beg that the President and Council of the Royal Society may be invited to suggest, at an early date, any supplementary measures which they may consider desirable. We have the honour to be, My Lord Duke, Your Grace’s most obedient, humble Servants, Mayo. Napier oF MAGDALA. JOHN STRACHEY. R. TEMPLE. J. F. STEPHEN. B. H. Extis. H. W. Norman. Enclosure No. 2. From Colonel J. T. Walker, R.E., Superintendent Great Trigonometrical Survey of India, to the Secretary.to the Government of India, Home Department, Simla. Dated Mussoorie, 11th August, 1870. Srr,—I have the honour to report that the pendulum-observations which have been carried on since the year 1865, by Captain Basevi, in con- 1870. ] On the Indian Pendulum-observations. 99 nexion with the operations of the Trigonometrical Survey of India, at the recommendation of the President and Council of the Royal Society, are now nearly completed, in conformity with the original programme of opera- tions which was sanctioned by the Right Honourable the Secretary of State for India, in his military letter No. 271, dated 23rd August 1864, to the Governor-General in Council. (2.) The results are of much importance, not only as affording inde- pendent information on the figure of the earth, but as throwing some light on “the laws of the local variations of gravity which are superposed on the grand variation from the poles to the equator ;’’ thus it will, I trust, be conceded that they amply fulfil the purposes contemplated in the ‘Correspondence and Proceedings of the Council of the Royal Society concerning Pendulum-Observations in India.’ (3.) But, before the operations are brought to a close, I think it is desirable that the President and Council of the Royal Society should be informed of what has been done hitherto, and of what remains to be done to carry out the original programme of operations ; also that they should be invited to suggest any supplementary measures which they may consider necessary in order to complete the operations, and thus perfect a work which was commenced at the suggestion of the President and with the hearty approval of the Council, and in the success of which they take a lively interest. (4.) I have therefore prepared the accompanying note on the opera- tions in explanation of what has been done hitherto, and of what remains to be done to complete the original programme; and I beg leave to request chat the Secretary of State may be moved to communicate it to the President and Council of the Royal Society, and to invite their opinions and suggestions. The Note is accompanied with a map on which the positions of the pendulum stations are indicated, I have the honour to be, Sir, Your most obedient Servant, J. T. Waker, Colonel R.E., Supdt. Great Trigonometrical Survey of India. Note on the Pendulum-observations in India, which are being carried on by Captain J. P. Basevi, in connexion with the operations of the Great Trigonometrical Survey of India. The observations have been made with the two invariable pendulums of the Royal Society, which are known as No. 4 and No. 1821. The number of vibrations in twenty-four hours is determined by observing the coinci- dences of each pendulum with the pendulum of a clock by Shelton, which is also the property of the Royal Society. The pendulums are swung, one at a time, in the receiver of a vacuum apparatus out of which as much air as possible is withdrawn by an air-pump, and the rate of the clock is de- termined every night. 100 On the Indian Pendulum-observations. [Nov. 24, (2.) Captain Basevi’s daily course of procedure is as follows. At 6 A.M. he sets in motion the pendulum which is under observation. At 7 a.m. he observes three coincidences and reads the thermometers and pressure- gauge. Between 7 a.m. and 4 p.m. he observes a coincidence and reads the thermometers and the gauge, five times at intervals of 1} hour. At 4 p.m. he closes this portion of the work by observing three coincidences and again reading the thermometers and the gauge. Thus for nearly ten hours of the day Captain Basevi never permits himself to be absent for more than a few minutes at a time from the pendulums. These frequent ob- servations are necessary in order that the temperatures may be exactly determined. At 8 to 10 p.m. he observes transits. (3.) Originally it was expected that, by employing a vacuum-apparatus, the pendulum might be vibrated for twenty-four hours before the vibrations became too small for the observation of coincidences, and consequently that the rate derived from the coincidences would be wholly independent of irregularities in the clock’s rate in different parts of the twenty-four hours. But this would have necessitated observations of the temperature at regular intervals throughout the twenty-four hours, which, as a rule, would have been impossible, though a few such groups of observations have been taken experimentally. Moreover at the commencement of the operations the vacuum-cylinder could not be made sufficiently air-tight to admit af so protracted an observation. (4.) Each pendulum is observed a certain number of days with the face to the front, and then as many days with the face to the rear. At the first four stations observations were taken for five days on each face, making altogether twenty days’ observations for both pendulums; as, however, it was found that the theoretical probable error of the mean of the ten days’ observations by a single pendulum was only +°05 of a vibration, the number of observations was subsequently limited to six days on both faces, making altogether twelve days’ work at each station. (5.) The observations are now being printed in the office of the Trigo- nometrical Survey, and a few specimen pages accompany this note. A preliminary abstract of the mean results by both pendulums is also given, and a map indicating the positions of the stations of observation*. (6.) The results obtained hitherto are not final; the coefficients of the corrections for temperature and pressure have not yet been conclusively determined, and the reductions to mean sea-level will probably be effected when the calculations of the influence of local irregularities in the crust of the earth have been carried to a greater distance from the stations than has hitherto been practicable. (7.) Of these corrections the most important is that for temperature ; the mean temperature of the observations ascends from a minimum of 54° at the base station Kew, to a maximum of 88° at Namthabad, being a * [It has not been thought requisite to publish this map.—G. G. S.] 1870.] On the Indian Pendulum-observations. 101 range of 34°; as the correction is approximately equal to one vibration for 2° of temperature, or seventeen vibrations for the extreme range, the true value must necessarily be determined with the utmost possible accuracy. (8.) In Section XIII. of my General Report on the Operations of the Trigonometrical Survey for 1866-67, I have fully described certain mea- sures which were taken to determine the coefficient of linear expansion. Briefly, they were as follows: vibrations were observed, at high and low temperatures, under the lowest pressure which could be obtained in the vacuum-apparatus at Kaliana, and at the natural pressure at Masoori; the expansions were also determined at high and low temperatures by direct micrometric measurement, with the following results :-— Pressure, in Factor of expansion inches. for 1° Fahrenheit. At Kaliana .. 3°5 000,011,10 : ,, Masoori .. 235 000,010,01 } LY) ORI eee Delia ss, 27°7 000,009,73 by direct measurement. Thus the value of the expansion which was determined from vibrations under a pressure of 3°5 inches was 14 per cent. greater than the value determined by direct measurement, at the natural pressure. I stated in my report that ‘‘ whether this is due to an actual increase of expansion for a decrease of pressure or to the action of other phenomena which are at present unknown or only imperfectly known, is a problem for future solution.” (9.) Experiments have been made at the Kew Observatory for the purpose of investigating this question; they are described in the ‘ Pro- ceedings of the Royal Society,’ No. 113, 1869. Owing, however, to difficulties which were experienced in working with artificial temperatures, the results were not conclusive as regards the present difficulty, and the hope was expressed that the question would find its best solution by our labours in India. (10.) The temperature-coefficients which have been employed in the preliminary reductions are those which were obtained from the observations at Kaliana, viz. : For No. 4 pendulum 0°485 vibration per diem for 1° Fahrenheit. 29 No. 1821 9 0:470 : 29 9 99 (11.) The pressure-coefficient which has been employed hitherto is the mean of the two values determined at Kew, or 0°32 vibration per diem for each inch of pressure at 32° Fahrenheit. (12.) In the reductions to the sea-level, the surface-density has been assumed to be half the mean density of the earth. Dr. Young’s formula has been used exclusively for stations situated on tolerably level plains, but for stations on hills the observations have been first reduced to the general level of the country by computing the vertical attraction of the elevated mass down to this level, the mass being divided into a number of 102 On the Indian Pendulum-observations. [Nov. 24, compartments by concentric circles and radii ; they have then been reduced to the sea-level by Dr. Young’s formula. The stations thus corrected are Masoori, Usira, Ehmadpur, and Somtana; at Masoori, curvature was taken into account, and the calculations were extended to a distance of 100 miles all round; but at the three other stations curvature was not allowed for, as the calculations were only carried to a distance of one mile. (13.) The preceding details will suffice to explain all that is necessary regarding the observations, and the preliminary results which have been derived therefrom which accompany this note. I will therefore now pro- ceed to indicate the principles by which we have been guided in selecting the positions of the pendulum-stations. (14.) In the first instance, the original programme of observing at a certain number of stations of the Great Are was duly carried out; the pendulums were swung at eighteen stations between Cape Comorin and the Siwalik Hills at the base of the southern slopes of the Himalayas, and at two stations north of the Siwaliks. 3 (15.) As yet no observations have been taken on the higher ranges, or on the tablelands, of the Himalayas, and thus the full influence of: these ranges in producing local variations of gravity has not yet been ascertained. But the observations at the five northernmost stations indi- cate that there is much probability that the density of the strata of the earth’s crust under and in the vicinity of the Himalayan mountains 1s less than that under the plains to the south, the deficiency increasing as the stations approach the Himalayas, and being greatest when they are north of the Siwaliks. On the other hand, the observations at the five southern- most stations show an increase of density in proceeding from the interior of the Peninsula to the coast of Cape Comorin. Thus both groups of observations tend to confirm the hypothesis that there is a diminution of density in the strata of the earth’s crust under mountains and continents, and an increase of density under the bed of the ocean. (16.) In order to test this hypothesis still further, as soon as the observations at the stations of the Meridional Arc were completed, the pendulums were taken to an ocean station—the Island of Minicoy, in the same latitude as Punnez, and about 250 miles from the mainland ; and afterwards to five stations on the east and west coasts, each in nearly the same latitude as one of the stations in the Meridional Arc. Thus the comparisons between the local variations of gravity under the continental, the coast, and the ocean stations are independent of an exact knowledge of the normal variation of gravity in proceeding from the poles to the equator. It will be seen that, without a single exception, gravity at a coast station is in excess of gravity at the corresponding inland station, and that at the ocean station it is greater than at the corresponding coast station; thus: 1870. ] On the Indian Pendulum-observations. 103 At Alleppy the pendulum makes 2°41 vibrations more than at Mallapatti. », Mangalore Ae 2°62 fe Bangalore. », Madras a 2°42 Me Bangalore. », Cocanada ce 2°78 Kocundal. », Calcutta a 3°19 i Ehmadpur. », Minicoy . 3°90 ey Punne. (17.) I may observe that the coast stations were selected at places as far removed as possible from mountain-ranges, in order that the results might not be affected by the local variations of gravity under mountains. For this reason additional stations could not be obtained on the west coast, because to the north of Mangalore there is a range of mountains running parallel to the coast at a very short distance. (18.) Having completed these observations, Captain Basevi returned to the head quarters at Dehra Doon last April, taking a set of observations at Kaliana en route, in order to ascertain whether the times of vibration of the pendulums had sensibly altered, through accident or wear of the knife- edges, in the period of four years which had elapsed since 1866, during which the apparatus had been transported (chiefly by land, but partly by sea) over a distance of several thousand miles, and the pendulum had been swung at twenty-two stations. The result indicates a slight alteration in the pendulums, probably by wear of the knife-edges, to an extent equiva- lent to one-third of a vibration in twenty-four hours. (19.) It now remains for Captain Basevi to investigate the true vacuum and temperature corrections, by experiments under artificial temperatures. He is at present making the requisite preliminary arrangements for the purpose, and will commence the experiments as soon as possible. They should be completed by the time that the snows of the approaching winter are sufficiently melted to permit of the passes on the great southern ranges of the Himalayas being crossed. Captain Basevi will then proceed to take observations in the inner Himalayas, on three extensive tablelands which are of great height, and are sufficiently removed from the neighbouring ranges to obviate the necessity for minute calculations of the masses of these ranges, calculations for which the requisite data are not forthcoming. The three tablelands are ‘“‘the plains of Deosai,” lat. 35° 5', long. 75° 30’, height 13,400 feet ; the plains north of the Changchenmo range, lat. 35° 15’, long. 79° 20’, height 16,000 feet; and “the plains of Hanle,’’ lat. 32° 50’, long. 79°, height 14,200 feet. Captain Basevi also proposes to take observations in the plains of the Punjab to the south of the Himalayas. Finally, he will descend the Indus, and take observations on the coast at Karachi, thus obtaining an additional coast station, which will be comple- mentary to an inland station on Colonel Everest’s Arc of the Meridian. (20.) It does not appear necessary that any more observations than these should be taken in India. But in the proceedings of the Council of the Royal Society in which the original programme of observations was dis- 104 On the Indian Pendulum. observations. [Nov. 24, cussed, it was proposed that observations should be taken at points nearer to the equator, at Ceylon, Singapore, or Borneo; also at Aden, a position of interest, “from being in a long line of depression where a large gravita- tion might be expected.’’? But as one of the two pendulums has already been swung by General Sabine at three stations on or between the equator and the parallel of Punnze, Captain Basevi’s southernmost station, and as a pendulum has been swung by Mr. Goldingham at the equator and at the Madras Observatory, which is also one of Captain Basevi’s stations, I] am inclined to think that there is no immediate necessity for taking observa- tions at Ceylon, Singapore, and Borneo, and that Captain Basevi’s opera- tions need not be prolonged for this purpose. On the other hand, how- ever, he will be easily able to observe at Aden; and he might also observe at some point in Egypt, on the plains which are crossed by the Suez Canal, with the great advantage that the stations would be complementary to certain of the stations in India; thus Aden would be compared with Madras and Bangalore, and the plains of Egypt with the Himalayan Mountains. (21.) I propose, therefore, that Captain Basevi should proceed from Karachi to England, taking observations en route at Aden and in Egypt, and bringing his operations to a close by a series of observations at the Greenwich Observatory, if the Astronomer Royal has no objections. I mention the Greenwich rather than the Kew Observatory because the true time can be obtained there from the astronomical clocks, whereas at Kew it can only be obtained by observation ; and if (as is probable) Captain Basevi arrives in the winter, pendulum-observations taken at Kew would be greatly delayed, as happened when the operations were commenced at Kew. Moreover, Greenwich appears to have been employed as a refer- ence station for pendulum-observations more frequently than Kew. J.T. WALKER, Colonel R.E., Supt. 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J. W. Strutt on the Theory of Resonance. [Nov. 24, II. “On the Theory of Resonance.” By the Hon. J. W. Srrurt. Communicated by W. Sporriswoopg, F.R.S. Received July 2, 1870. (Abstract.) An attempt is here made to establish a general theory of a certain class of resonators, including most of those which occur in practice. When a mass of air or other gas is enclosed in a space bounded nearly all round by rigid walls, but communicating with the external air by one or more pas- sages, there are certain natural periods of vibration or resonant notes whose determination is a matter of interest. If the dimension of the air- space is small compared to the wave-length of the vibration, the dy- namics of the motion is, in its general character, of remarkable simplicity. It is for the most part under this limitation that the problem is considered in the present paper. The formula determining the resonant note is = — a) u 2a N) where 7 is the number of complete vibrations per second, a@ the velocity of sound, and S the capacity of the air-space; ¢ is a quantity proved to be identical with the measure of electric conductivity between the interior of the vessel and the external space, on the supposition that the air is re- placed by a uniform conducting mass of unit specific conducting-power, and the sides of the vessel and passages by insulators. When there is more than one passage the formula is still applicable according to the above definition of c; and when the passages are sufficiently far apart not to in- terfere with each other, the resultant ¢ is by the electrical law of parallel circuits simply the sum of the separate values for each passage considered by itself. When this condition is not satisfied the value of c, thus found by mere addition, is too great. The question thus resolves itself into the determination of the conduc- tivity (or the resistance which is its reciprocal) for different forms of passages or openings. The case of openings, which are mere holes in the sides of the vessel, has been already treated, although in a very different way, by Helmholtz, who, in his celebrated paper on vibrations in open pipes, compared his theory with the observations of Sondhauss and others on the notes produced, when such resonators are made to speak by a stream of air blown across the mouth. Sondhauss has also given an empirical formula applicable when the connecting passages are of the form of long cylindrical necks. These previous results are in agreement, as far | as they go, with the formula here investigated, and which is applicable whatever may be the length of the neck. If L be the length and R the L+5R be 5 . radius, aa the electrical resistance eaten cae 1870.] Hon. J. W. Strutt on the Theory of Resonance. 107 This supposes the neck a circular cylinder. If the section be an ap- proximate circle of area o, we may put a Be fe —at/t When the neck is very long the second term may be neglected, and when L is very small the first term becomes insignificant. In the third part experiments are described which were instituted to compare the general formula with observation, and which gave a satisfactory agreement. The value given above for lis only approximate. It is proved, however, c that the resistance of a finite cylindrical conductor whose plane ends lie in two infinite insulating planes, but join on to conducting masses on the further side, corresponds to a length La of the cylinder, where L 10°615—e~ °R a< 2°305 R L ie77l Sere T >ER. As a particular case, it appears that the correction to the length of an organ-pipe, supposed, as in Helmholtz’s paper, to be surrounded at the mouth by a wide flange, lies between °785 R and °8282 R. Approximate formulee are investigated for the resistance of tubes which are not exact circular cylinders. It will be sufficient to particularize here the case of tubes of revolution. The resistance is shown to lie between the two limits 1 (‘de iy | 1 dy\? 2{ ral 143(Z) } as where y denotes the radius of the tube at the point z. When there is more than one vessel in the vibrating system, there are several independent periods of vibration corresponding to the degrees of freedom. The theory of these vibrations is also considered. In the experimental part of the investigation the object is to determine with sufficient precision the pitch of the resonant note. This is generally done by causing the resonator to speak. For several reasons, which are detailed, I consider this course unsatisfactory, and have availed myself of other indications to fix the pitch, which are not, indeed, capable of so great an apparent precision, but yet are more to be depended on. and we 108 Dr. A. W. Hofmann on the Aromatic Cyanates. [| Nov. 24, III. “On the Aromatic Cyanates.” By A. W. Hormann, LL.D., F.R.S. Received July 30, 1870. The only member of this class which has hitherto been studied is the phenylic cyanate. About twenty years ago I discovered this compound among the products of a very complex reaction which took place on sub- mitting to destructive distillation a substance which I then named ox- amelanil or melanoximide*, but which at the present time would be con- sidered as oxalyldiphenylguanidine. The phenylic cyanate, which I then called anilocyanic acid, is formed only in very small quantity ; I never had more than a few grammes of the substance in my possession ; and it was only from the sharply defined properties of the body that I was enabled to describe it correctly. Eight years later I again met with this compound. When I found that diphenylsulphourea, by treatment with anhydrous phosphoric acid, split up into aniline and phenylic mustard-oil, the idea naturally suggested itself to utilize this reaction for the preparation of phenylic cyanate, by distilling normal diphenylurea with anhydrous phosphoric acidf. In fact, phenylic cyanate can be prepared in this way. On heating dry diphenylearbamide with anhydrous phosphoric acid, the frightful odour of the cyanate was immediately developed; and on distilling the mixture of the two bodies, the phenylic cyanate came over in colourless drops. When, however, the experiment was made on a somewhat larger scale, the product was so small that I was compelled to consider this process more as a mode of formation of the substance than as a method for its preparation. Lately my experiments on the mustard-oils led me to a simple process for the preparation of the phenylic cyanate and its homologues. In a former paper { I drew attention to the facility with which the mus- tard-oils combine with a molecule of alcohol. When phenylic mustard- oil is heated for a considerable time with alcohol, it yields the beautifully crystalline half sulphuretted phenylurethane, which, when distilled alone, or, still better, with phosphoric anhydride, again splits into its com- ponents alcohol and phenylic mustard-oil. Taking into consideration the result of this experiment, ought we not to obtain the phenylic cyanate on distilling phenylurethane with phos- phoric acid ? Phenyl Series. Phenylurethane.—The phenylurethane is known; I had already ob- tained it in the above-mentioned researcn on the phenylic cyanate. When this substance was treated with methyl, ethyl, or amyl alcohol, the phenyl- urethane of the methyl, ethyl, or amyl series was obtained §. Since then * Hofmann, Ann, Chem. Pharm. vol. Ixxiv. p. 9. + Hofmann, Proc. Roy. Soc. vol. ix. p. 275. { Hofmann, Berichte Deutsch. Chem. Gesell. Jahrg. 1. 8. 116. § Hofmann, Ann, Chem. Pharm, vol. Ixxiv. p. 16. 1870. ] Dr. A. W. Hofmann on the Aromatic Cyanates. 109 the phenylurethane of the ethyl series, phenylcarbaminic ether, has been carefully investigated by Messrs. Wilm and Wischin*, who obtained it by the action of chlorocarbonic ether upon aniline. I have repeated the experiment of Messrs. Wilm and Wischin, and can fully confirm their results. The body prepared in this manner is identical with that which I formerly obtained. The melting-point of the substance, after repeated crystallization, was found to be 51°; Messrs. Wilm and Wischin gave 51°°5-52°. The boiling-point was about 237°, the same as that found by those gentlemen. Messrs. Wilm and Wischin state that the phenylcarbaminic ether (which they call carbanilidic ether) is volatile without decomposition. I find that although the greater portion escapes decomposition when dis- tilled, yet part of it splits up mto phenylic cyanate and alcohol, C, H,, NO,=C, H, NO+C, H, 0, which is perfectly in accordance with what I expected from the study of the half-sulphuretted phenylurethane. On distillation, the well-known and familiar odour of the phenylic cyanate is immediately developed ; and, in fact, Messrs. Wilm and Wischin must also have observed it; for they say of the carbanilidic ether, “the vapour of this body excites a copious flow of tears, but when diffused has a faint resemblance to bitter almond- oil.’ What Messrs. Wilm and Wischin smelt was the phenylic cyanate. If the mixture of phenylic cyanate and alcohol, obtained along with a large quantity of phenylurethane by the distillation of the latter, be allowed to stand for twenty-four hours, the odour of the cyanate will have disap- _ peared entirely ; the cyanate and alcohol have recombined with formation of phenylurethane. After these results of the behaviour of phenylurethane under the influ- ence of heat, there could be no doubt that phenylic cyanate would be ob- tained by the employment of phosphoric anhydride. Experiment has fully confirmed this expectation. Phenylic Cyanate.—When phenylurethane is heated with anhydrous phosphoric acid, a considerable quantity of a colourless liquid distils over of great refractive power, having a pungent odour, and attacking the eyes strongly. This liquid is phenylic cyanate, which only requires redistilla- tion to be obtained pure. As in all operations in the aromatic series in which phosphoric anhydride takes part, the quantity obtaimed is by no means that required by theory, although it approaches it. For more than one reason I had desired to discover a method for the preparation of the phenylic cyanate. I was now enabled to determine more accurately the boiling-point of the body ; it is 163°. In my former determination, for which only a few grammes were available, I had found ito bell 7/5". The specific gravity of the phenylic cyanate at 15° is 1:092. Its vapour- * Ann. Chem, Pharm. vol. exlvii. p. 157. VOL. XIX. : K 110 Dr. A. W. Hofmann on the Aromatic Cyanates. [Nov. 24, density was determined in aniline vapour. The numbers obtained con- firmed the formula already established by analysis. CO C,H, NO= 6 } N. Theory. Expt. Specific gravity of vapour compared with hydrogen 59:50 58°90 gf x » "compared with am.) stele 4°09 With respect to the behaviour of the body with other substances, I can refer to my former paper. With water it yields carbonic acid and diphenylcarbamide ; in contact with alcohol the urethane is reproduced ; it combines immediately with ammonia and its derivatives, forming an inconceivable number of ureas. But, besides other combinations, it ex- hibits a remarkable reaction. I may mention that the possession of a considerable quantity of phenylic cyanate has given me an opportunity of again observing the behaviour of this body towards triethylphosphine, formerly described*. If a glass rod, moistened with the phosphorus base, be dipped into a considerable quantity of phenylic cyanate, in a few moments it becomes very hot, and the whole solidifies to a mass of beau- tiful crystals. The principal product formed in this reaction is a body insoluble in water, and not very soluble in boiling alcohol, from which it crystallizes on cooling in fine prisms, which in an analysis formerly published gave numbers corresponding to cyanurate of phenyl, and may therefore be re- garded as phenylic cyanurate. I must, however, leave it an open question, whether this substance is identical with the phenylic cyanurates, obtained the one by the action of chloride of cyanogen on phenol+, the other from triphenylmelamine {. Now that the necessary material can be obtained, there is no difficulty in a complete investigation of this body, as well as the by-products formed by the reaction in question. We may here find room for some observations on the homologues of the phenylic cyanurate. Tolyl Series. Tolylurethane.—Chlorocarbonic ether acts with the greatest violence on toluidine, so that it is advisable to conduct the reaction in the presence oj ether. COcl C,H _CO(C, H,) HN C,H earot? [aN [oO Gao? on The ethereal solution, filtered from the toluidine hydrochlorate, on evapora- tion leaves the tolylurethane as an aromatic oil, which, when cooled by a * Hofmann, Ann. Chem. Pharm. Suppl. vol. i. p. 57. ¢ Hofmann, Berichte Deutsch. Chem. Gesell. Jahrg. iii. 8. 275. { Hofmann, Berichte Deutsch. Chem. Gesell. Jahrg. iii. 8. 274. 1870. ] Dr. A. W. Hofmann on the Aromatic Cyanates. 111 freezing-mixture, solidifies with difficulty, and, as a rule, only after stand- ing some time. Tolylurethane is insoluble in water, but. dissolves with ease in alcohol and ether, and crystallizes from the former in fine long prisms, which melt at 32°. Tolylic cyanate.—When distilled alone, the tolylurethane behaves like phenylurethane, the greater part passing over undecomposed, whilst a small portion is resolved into toluylic cyanate and alcohol. CO (C, H,) HN CO C,H i Gnjoncm)s* 1)? When the distillation is performed in the presence of phosphoric anhy- dride, the alcohol is fixed, and the tolylic cyanate passes over in a nearly pure state. It only requires rectification to be perfectly pure. Tolylic cyanate is a colourless liquid, boiling at 185°, of high refractive power, and a powerful odour exciting a copious flow of tears. A vapour-density determination in aniline vapour gave the following results :— Theory. Expt. Specific gravity of vapour compared with hy- I. II. QIRTGTD, OC CRS S ane ie ee mer ieee an 66°5 64°6 65°7 Specific gravity of vapour compared with air 4°61 4-48 4°56 Tolylic cyanate behaves towards water and ammonia and their deriva- tives like phenylic cyanate. On treatment with water ditolylurea is pro- duced with evolution of carbonic acid ; with the alcohols it forms the cor- responding urethanes, and with ammonia and the amines it yields a group of compound ureas. Triethylphosphine produces the same change as in the phenyl-com- pound ; it takes place, however, somewhat more slowly. , The very beau- tiful crystalline compound thus formed I hope soon to be able to in- vestigate. Xylyl Series. The experiments were precisely similar to those in the phenyl and tolyl series. The reaction with xylidine is, however, somewhat more sluggish than with aniline and toluidine. Aylylurethane, C,, H,, no,=°° (6, wos | O, 2 5 crystallizes in fine needles, which melt at 58°. Aylylic cyanate, C,H,NO=-2 In : : : WC. H, ‘ is a colourless, highly refractive liquid of feeble odour, and attacking the eyes but slightly. The boiling-point is about 200°. Its vapour-density was taken in aniline vapour. 112 Dr. A. W. Hofmann on the Aromatic Cyanates. [Nov. 24 . Theory. Expt. Specific gravity of vapour compared with hydrogen.... 73°50 74°69 oS is » compared with air. ..2... 4: 5°10 5°18 Xylylic cyanate exhibits the same reactions as those which are so pro- minent in the corresponding members of the phenyl and tolyl series, but somewhat weaker. The combinations which take place almost immediately in the case of phenylic and tolylic cyanates often require days with the xylylic cyanate. Evenin the presence of triethylphosphine xylylic cyanate solidifies but slowly. Naphthyl Series. Naphthylurethane.—The formation of this analogue of urethane was effected by the action of chlorocarbonic ether on naphthylamine. It is insoluble in water, more soluble in alcohol, and crystallizes from the latter in needles which melt at 79°. Its composition is expressed by the for- mula CO(C.,, H.) HN Ct Noe Yo Naphthylic cyanate.—A short notice of this compound has already appeared. When I had found that diphenylcarbamide gave phenylic cya- nate by distillation with phosphoric anhydride, Mr. Vincent Hall* made the corresponding experiment in the naphthyl series, but only obtained a very small quantity of the naphthyl compound. The formation of the naphthylic cyanate by this method was, however, established. The naphthylic cyanate is obtained in considerable quantity by the dis- tillation of naphthylurethane with phosphoric anhydride. It is a colour- less, not very mobile fluid, whose boiling-point is about 269°-270°. Its vapour has the pungent odour which is peculiar to the cyanates, but at the ordinary temperature naphthylic cyanate is almost odourless. Its com- position is expressed by the formula I have, moreover, satisfied myself of its correctness by the reactions of the body. On considering its behaviour with water and alcohol, and their de- rivatives, there can be no doubt as to the nature of the compound. The facility with which these reactions take place with the naphthyl compound is remarkable. The naphthylic cyanate acts with incomparably greater quickness and precision than the analogous xylyl-compound; this is par- ticularly shown in the action of triethylphosphine, which causes the cyanate of the naphthy] series to solidify almost instantaneously. I have to give my best thanks to Mr. F. Hobrecker for his efficient assistance in the prosecution of the above research. * Proc. Roy. Soc. vol. ix. p. 365, 1870. ] Annwersary Meeting. 113 November 30, 1870. ANNIVERSARY MEETING. General Sir EDWARD SABINE, K.C.B., President, in the Chair. General Boileau, for the Auditors of the Treasurer’s Accounts on the part of the Society, reported that the total receipts during the past year, including a balance of £324 4s. 7d. carried from the preceding year, and £800 taken from the Oliveira bequest on deposit, amount to £5410 3s., and that the total expenditure inthe same period amounts to#5282 13s8.9d., leaving a balance of £91 18s. 3d. at the Bankers, and of £35 11s. in the hands of the Treasurer. The thanks of the Society were voted to Mr. Spottiswoode and the Auditors. The Secretary read the following Lists:— — Fellows deceased since the last Anniversary. Royal. His Imperial and Royal Highness Leopold the Second. On the Home List. Edward William Brayley, Esq. Augustus Matthiessen, Esq., Ph.D. Alexander Bryson, M.D. William Allen Miller, M.D.,D.C.L., The Hon. and Rev. Richard Carle- Treas. R.S. ton, M.A. Arthur Morgan, Esq. Sir James Clark, Bart., M.D. The Right Hon. Sir Frederick Pol- Charles Collier, M.D. lock, Bart., M.A. James Copland, M.D. | The Rev. William Taylor. John Thomas Graves, Esq., M.A. James Vetch, Capt. R.E. WilliamAlexander Mackinnon, Esq., Augustus V. Waller, M.D. M.A. John Wilson, M.D. James Prince Lee, Lord Bishop of Manchester. On the Foreign List. Heinrich Gustav Magnus. 114 Anniversary Meeting. _ [Nov. 80, Change of Title. The Bishop of Oxford ¢o Bishop of Winchester. Fellows elected since the last Anniversary. William Froude, C.E. Capt. Robert Mann Parsons, R.E. Edward Headlam Greenhow, M.D. | William Henry Ransom, M.D. James Jago, M.D. George Granville William Suther- Nevil Story Maskelyne, M.D. land-Leveson-Gower, Duke of Su- Maxwell Tylden Masters, M.D. therland, K.G. Robert, Lord Napier of Magdala. Robert H. Scott, Esq. Alfred Newton, M.A. George Frederic Verdon, O.B. Andrew Noble, Esq. Augustus Voelcker, Ph.D. Capt. Sherard Osborn, R.N. Samuel Wilks, M.D. Rev. Stephen Parkinson, B.D. On the Foreign List. Anders Jons ‘Angstrom. | Joseph Antoine Ferdinand Plateau. The President then addressed the Society as follows :— GENTLEMEN, Since our last Anniversary, another volume, the fourth, of the Society’s Catalogue of Scientific Papers, has been published, bringing the alphabetical list of titles down to PO Z. Pursuant to the arrangement which I announced last year, Professor Carus of Leipsic spent some weeks in London during the spring, in preparing the Index Rerum. It was his intention to come again in the autumn to continue his labours ; but the outbreak of the war prevented him from leaving his home and family, so that the resumption of his work is postponed for the present. The preparation of the Index Rerum will, however, continue to engage the careful attention of the Library Committee ; meanwhile I am glad to say that good progress is being made with the printing of Volume V., of which a fourth part is now in type. In the last summer we have had the misfortune of losing our Treasurer, Dr. William Allen Miller, one of our most valued and distinguished Fellows, and one who surely enjoyed the regard, as well as the high esteem, of all who knew him. UHe was also one who, in addition to important direct scientific work, had for several years shared actively in the cares and the labours called for by the many and varying subjects referred each year to the Royal Society, as represented by its Officers and Council, and by the special Committees appointed by them to deal with each case as it arises. 1870. ] President’s Address. 115 Tt may be in the recollection of some of the Fellows that, in the Anni- versary Address delivered in 1863, I ventured to suggest the interest and probable value of a series of Pendulum Experiments at the principal stations of the Great Indian Arc. Encouraged by the warm concurrence in opinion and promised support of Colonel Walker, Superintendent of the Indian Trigonometrical Survey, a circular note was addressed by myself, with the concurrence of the Council, to several of the Fellows of the Royal Society conversant with the subject; and the correspondence, including an outline of the proceedings which in Colonel Walker’s judgment would be required in India, should the experiments receive the sanction of the Indian autho- rities, was submitted through the proper channels to the Secretary of State for India, and received the sanction of the Indian Government. The pendulums and accompanying apparatus having been prepared at the observatory of the British Association at Kew (aided by a special subsidy from the Government-Grant Fund placed annually at the disposal of the Royal Society), were embarked for India, in March 1865, under the charge of Captain Basevi of the Royal Engineers, appointed to conduct the experiments with them in India. These have been executed in great part, and are still in progress, under that officer’s superintendence. In the meantime the Royal Society has been favoured by a recent communication from the Secretary of State for India, enclosing Col. Walker’s official report of what has been accomplished, and of what remains to be accomplished in India, to complete the original programme—and transmitting a despatch signed by the Governor General and other high authorities of the Indian Go- vernment, requesting that the President and Council of the Royal Society may be invited to suggest at an early day any supplementary measures which they may deem desirable. It appears that, at the date of Colonel Walker’s report, pendulum ex- periments had been completed at twenty-five stations on the mainland of India, extending from Cape Comorin in lat. 8° 5! N. to Mussoorie in lat. 30° 28’ N., and at a 26th station, on the Island of Minicoy, midway between the Maldives and the Laccadives, in lat. 8° 6’—and that five additional stations had been allotted as the work of the present year, four of which are in the high tablelands of India between 32° and 36°N., and one near the mouth of the Indus. I had the pleasure of receiving,.about the same time, a letter from Colonel Walker himself, announcing his intention of being in England, on furlough, towards the end of December, when he might be personally informed of any further uses to be made of the pendulums in India—pro- posing also that, on the return voyage to England, Captain Basevi should be instructed to obtain the rates of the pendulums at Aden (suggested as desirable, from its geographical peculiarities, by our Foreign Secretary, in a letter to myself, printed in the Minutes of Council of June 1864), and at a station to be selected in the vicinity of the Bitter Lakes. Colonel Walker also suggested that, on the arrival of the pendulums in England, 116 Anniversary Meeting. [Nov. 30, their rates should be ascertained. at the Royal Observatory at Greenwich, in addition to the necessary repetition of the original experiments at the Kew Observatory. The documents thus referred to having been read at a recent evening meeting, and suitable communications having been made to those Fellows of the Society who participated in the original recommendation of the experiments, a Committee has been named, with Colonel Walker as one of its members, to meet as soon as may be convenient after his arrival in England, to prepare a reply to the Indian Government. It may perhaps be permissible to notice, on this occasion, that the experi- ments on the retardation which pendulums experience when vibrated in different gases, for which a sum was allotted some years since by the Government-Grant Committee, yet await the supervision of an experimen- talist having sufficient leisure and interest in the subject. The apparatus at Kew may be made quite suitable for the purpose ; and the occasion is favourable. The successful voyage and safe return of the North-German Polar Ex- pedition is an event on which the Royal Society may add its sincere con- gratulations to those of the public at large. The progress of geographical discovery, connecting with itself, as it does, the advancement of many physical sciences which require, either for extension or for confirmation, the assu- rance derived from experimental research, has for nearly three centuries been carried on in the Arctic Regions, where it has afforded a common field for the enterprises of the British and of the northern continental nations—enterprises conducive to hardihood, and to qualities which are the result of a generous emulation, unmixed with the deteriorating influences which are but too apt to be generated by the rivalries of war. The earliest of these undertakings were indeed antecedent to the existence of the Royal Society ; but on their revival—which took place in 1818, at the termination of the great War by which Europe had been desolated for so many years— the British Government, at the instigation of the Royal Society, was the first to recommence, and for several years to continue, a succession of under- takings, in which we have now to recognize the successful participation of more than one kindred and allied people. The German expedition consisted of the ‘ Germania,’ a steamer of about 80 tons, duly strengthened for encounters with ice, commanded by Captain Koldeway, who seems to have possessed in an eminent degree the special qualifications required in such an enterprise. Besides her naval comple- ment of twelve officers and seamen, four gentlemen were embarked for special scientific services, to whom were confided, among other objects, the researches preliminary to the measurement of an arc of the meridian on the coast-line of East Greenland. The ‘Germania’ was accompanied by a smaller vessel. not furnished with steam apparatus, named “The 1870. ] President’s Address. 117 Hansa.” Thus unequally provided, the two vessels parted company in the ice which has to be traversed in the passage from Kurope to Hast Green- land, and did not subsequently rejoin ; the ‘ Hansa’ having been unable to force her way through the ice, was finally wrecked by it, the crew escaping on the ice, and being conveyed, on a constantly lessening ice-raft, to near the latitude of Cape Farewell, whence they made their way in their boats, which they had preserved, to the nearest Danish settlements, from which they have returned without loss of life. The ‘ Germania’ having forced her way through the ice by the aid of steam, anchored on the 5th of August, 1869, in ie small but secure bay, in lat. 74° 32', and long. 18° 53’ W., on the south side of the island on which my pendulum experiments had been made forty-six years before. They subsequently visited Cape Philip Broke in lat. 74° 55’, which had been the first landing-point on the coast when examined by Captain Cla- vering and myself in the British Expedition of 1823. The highest latitude reached by the ‘ Germania’ was 75° 31', where she was stopped by the ice, and returned to winter in the bay, in the Pendulum Island, in which they had first anchored. The extreme northern point of the coast which had been seen in 1823, named by Captain Clavering “The Haystack,” in lat. 75° 42', was visited in sledges in the spring of 1870, by parties engaged in the survey operations, which extended into the 77th parallel. One of the most noteworthy results of this expedition, and it may possibly prove one of the most important, is the discovery that the lands adjacent to the bays and fiords in Kast Greenland abound in flocks of Rein- deer and Musk-oxen, and in smaller game of various descriptions. It is stated that during the stay of many months on the coast the crew were rarely without an abundant supply of fresh food, derived from the country itself. It is possible that this abundance of game, combined with the magnificence of the glaciers and of the mountain scenery accessible by the deeply intersect- ing fiords, may tempt persons who in these days have trained themselves to arduous mountain-ascents to visit a country in which panoramic views over yet unexplored regions of the globe might be a recompense for their toils and dangers. The mountains rising from one of the fiords visited by the surveying parties of the ‘Germania’ attain a height of 14,000 feet. The view from such an elevation might possibly accomplish more than many maritime expeditions, to shape out the yet unknown geography of Northern Greenland *. The distance in a direct line from the most northern point of the coast visited by the surveying parties of the ‘Germania,’ to the expanse of open ocean seen by Kane and Hayes to the north of Kennedy’s Channel, and described as abounding in animal life and * The officers of the ‘Germania’ speak with enthusiasm of the scenery in the deep fiord in lat. 73°, up which they steamed more than 70 nautical miles in a westerly di- rection. They say :—“ The further we went the milder we found the temperature ; the scenery was grand asin the Alps. The true interior of Greenland showed itself with constantly increasing grandeur and beauty to our admiring eyes.” pEVOL.: XIX. I 118 Anniversary Meeting. [Noy. 80, indicating in many ways the proximity of an extensive open sea, is not more than about 400 geographical miles. The Survey which has been recently made under the auspices of the Swedish Government, with a view to the measurement of an are of the meridian at Spitzbergen, may have suggested the corresponding survey of the coast of East Greenland. But, without doubt, the extent of con- tinuous land in the direction of the meridian is much greater in Greenland than in Spitzbergen; whilst the fiords, which so generally characterize the Greenland coast, would probably greatly facilitate the access to localities suitable for trigonometrical stations. The return of the ‘ Germania,’ whilst the objects of her mission were still incomplete, was occasioned by the - necessity of replacing her boiler, which had wholly failed ; and she will pro- bably resume her operations in the coming year. It is understood that the Swedes also are organizing another Spitzbergen expedition, of which the special objects have not yet been announced. It may be hoped that the remeasurement of the Fairhaven Hill may be remembered on this occasion. Its height in 1823 was determined with great care, both geometrically and barometrically, by Captain Foster and myself (Phil. Trans. 1824, Art. xvi.). _ The permanency, or otherwise, in the elevation of marked features of the land is a subject of considerable geological importance in some countries ; and Spitzbergen is one of those in which it has been occasionally questioned. The discrepancy in the action of the currents experienced in 1823 and 1869, on the extensive ice-fields which occupy the middle space between the coasts of Kurope and of East Greenland, is very noteworthy. In 1823 the most careful observations, of officers greatly practised in such investi- gations, failed to discover any perceptible surface-current whatsoever, either by its effect on the ice itself, or on the surface-water of the sea between the ice and the Greenland coast; whilst in 1869 the crew of the ‘ Hansa,’ having taken refuge on the ice after the loss of their vessel, in the approxi- mate geographical position of 70° 50’ N. and 21° W., were carried by it to the lat. of 61° 12’ N. and long. (about) 42° W.,—being a drift extending over more than 500 geographical miles, accomplished in little less than 200 days, the average being somewhat less than three miles a day. In seas much encumbered by floating ice, currents are generally ascribed to the prevailing winds; and there appears to have been in 1869 a considerable amount of northerly gales. But the frequent existence of a current setting to the south and south-west down the coast of East Greenland has been recognized by the highest authorities, and is regarded by Forchhammer, in his valuable memoir on the Phenomena of the Sea, in the Philosophical Transactions for 1865, as a returning branch of the Gulf-stream, recog- nizable as such by the difference in the analysis of the polar and equatorial waters. This branch of physical research has doubtless received full attention from the officers of the ‘ Germania;’ and we must await the pub- lication of the complete account of the voyage for the full details. The plant-remains of the Miocene epoch, discovered in Spitzbergen and 1870. | President’s Address. HS Greenland, have given a new feature of interest to future explorations within the Arctic Circle. The valuable memoir which Professor Oswald Heer, of Zurich, has contributed recently to the Philosophical Transactions (1869, Art. XIII.), has added much to the evidence contained in his pre- vious papers of the existence, at that early period of the earth’s history, of a vegetation in some cases identical with, and in others scarcely differing from, that which now lives and flourishes in the Temperate Zone—a vege- tation comprehending oaks, planes, chestnuts, and even a Magnolia, the leaves and fruit of which were found in the North-Greenland deposits. Altogether, Professor Heer has identified no less than 137 species of the Arctic flora of the Miocene age; and he has moreover inferred, with great appearance of reason, that at the same era vegetation of the same cha- racter may have prevailed generally in lands within the Arctic Circle. The anticipation of future discoveries of plant-remains, adding possibly largely to the number of 137 species already recognized, must tend to give to land-explorations and excursions an interest which was. comparatively wanting to them when all that the explorer could anywhere hope to find (other than the scanty, though in some respects beautiful, flora which the rigours of the Arctic region at the present time still suffer to exist) was, at most, the less attractive fossil remains of much earlier geological ages, to the climatology of which less interest attaches than to that of the com- paratively recent (however ancient) Miocene age. There have been in the past year two vacancies in the list of Foreign Members of the Royal Society. The two gentlemen who have been elected are Professor Joseph Antoine Ferdinand Plateau, of Ghent, and Professor Anders Jons Angstrom, of Upsala. Professor Plateau has been an earnest worker in the field of physical science for above forty years. His memoirs, the titles of which (forty-six in number) are given in the fourth vo- lume of the Society’s Catalogue of Scientific Papers,.give evidence of the completeness with which he has treated the subjects he has taken up; and many of his experiments are remarkable for their ingenuity and originality. Questions in physical optics were the first to engage his at- tention. In this branch of science his researches were confined to the laws of visual appearances, including those relating to ocular spectra, the duration of impressions on the retina, and irradiation ; and though some of nis conclusions may have to be corrected, there is no doubt that in this special department he has done more than any one of his predecessors or contempo- raries. Another subject which has occupied him in his later years, and has supplied the materials of eleven memoirs, concerns the figures of equilibrium of a liquid mass without gravity. No one can contest the perfect origi- nality of this series of investigations, or fail to admire the simple and effective means by which he has carried out his experiments, and the saga- city with which he has arrived at results which have formed a new starting- 120 Anniversary Meeting. [ Nov. 30, point for mathematical investigations relating to the corpuscular theory. It is much to be regretted that Professor Plateau’s scientific labours for more than twenty years past have been carried on under a deprivation of sight occasioned by the ardent pursuit of his favourite science. Although totally blind, his experiments are of the most exquisite delicacy ; and the reasoning of which they form the material is as accurate and penetrating as the experiments themselves are beautiful. The second gentleman who is elected a Foreign Member, Professor Angstrom, is distinguished by his researches in many departments of physical science, and is entitled to rank among the very highest of those who have within a few years developed the powers of spectroscopy to their present marvellous extent. In fact, his ‘Optic Researches,’ 1853, contain the fundamental principles of nearly all that has been done since. The following notice is from the pen of the Rev. Dr. T. Romney Robin- son, F.R.S., of Armagh :— “From Huler’s theory of Resonance, he infers that, as a body absorbs all ‘* the series of oscillations which it can itself assume, it must, when heated so ‘“as to become luminous, emit the same rays which at a lower temperature it ‘absorbs. “Tt is hardly possible to announce more distinctly this important fact, on ‘which nearly all solar and stellar spectroscopy rests ; and itis much to be “reoretted that, from the ignorance of the Scandinavian languages which is “‘so general in this country, it was not known here till 1856. He proceeds “‘to examine the spectrum of the electric spark. It is traversed by two sets ‘of lines on an obscure ground. ‘The first of these belongs to air. The ‘lines reach across the spectrum, and do not vary with the nature of the “electrodes. The second set come from the electrodes ; they are in general ‘far brighter than the other, and, unless the discharge is powerful, are con- ‘fined to the vicinity of the electrodes. Hach metal has its own set ; but, ‘owing to the small dispersion of his spectroscope (one prism of 46°), he “thought some lines were common to two or more metals. Alloys showed ‘the lines of their components with no greater difference than could be ex- *‘plained by the want of power in his instrument. He shows that these ‘lines are not produced by interference. The solar spectrum may be re- ‘garded as a reversion of the electric one ; and heis convinced that the ex- ‘planation of the dark lines in the former embraces that of the bright *‘lines in the other. Each gas has its peculiar spectrum ; he notices the “ faintness of the oxygen-lines in air, and he describes the three bright bands “of hydrogen, and a fourth fainter. “Tn 1861, ina second memoir, he developed |. is theory of the reversion of ‘the lines. He had then obtained a better spectroscope and a large Ruhm- “ korff, with which he compared many of the solar with metallic lines. Many *‘ double lines belong to two metals. Gas-lines are more diffused and less ‘‘ sharply defined than those of metals, especially metals difficult of fusion. “He found no evidence of nitrogen or oxygen in the sun. 187 0.] President’s Address. 121 “His third memoir (1863) contains a determination of the wave-lengths “ of Fraunhofer’s principal lines, and others, 70 inall. As the same matter is * treated far more completely in a subsequent memoir, it is only necessary to ‘notice that he corrects his measures for the pressure and temperature of *‘ the air, for the temperature of the grating employed, and for the aberration “caused by a motion of the instrument in a direction at right angles to the “incident light. This last will cause a difference between the deviations on “each side of zero. In the high latitude of Upsala, and in an unfavourable ‘“summer, the observations which he made to test the reality of this correc- tion were neither sufficiently good nor numerous to satisfy him ; yet the *« difference which he found agreed very closely with what was computed. « Koo OUIGOUUROUOO DOUG ObDOODOOD puny [PP Aejdog 9 e Ge SOOO SEIOIOE BUICH EOI NOION) pecucee puny UW1BY.OULIGUL AA, 0 IL 9e¢ ss EA a, Saree Nang pun, uoYRuog. \9 GI CL POICIOI CROC ECHO NC ECR ECCI a Ei (Aqn¢ KovesoT) qsonbog ION Tag Base ioce a Sy fore gue ae (peutolqns etquy, tod sv) sosuodxa [eroue1 9 FI 980 GUO DO ODDDODOOOODUGUIGUOUCO omiOoodUOd te Aydeasouqry pue ‘SULARLOURT ‘Suipuig ‘aodegq ‘scurpeooorg pur suotorsuery, suyuig S II G1Z etateietaretavererclapeikioietelelelereiiiey sieves iarerets SUIPULT pure Aarerquys ou} LOF syooq (3). 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BL Beg: eee ea eee Scan ge op) e 61 Gre { OL8T gaa - Ti 99F sislolatulecveiaiela(eleleteteratalsintalstetsteretainiatsin ces WOSUeAg4 uo (13 Sg ore ee Oe, [Bee oO8T TE ta SwoRowUBA, Senmeg —|—O gr GIOK ~_(spung snag, J oaeose) soO}S wo spuOpLNE > I (9) Jil GGG @eeeeeseveese ee ee weer er eereeereeeeeer eee $} UOT Ss Fee CGH eco a ea se clan cea mae Pye deere ALeIGUT oy} LOZ syoor, 0 0 08g ce naan hh salads egaeeee reeeroe suomtsodul0g ~ 9 oe | GIF aoe e cee e roma srerserressst sees Ons ee eee eenes ansoleyen dyTUEIOG ou 0 0 O9T eee es eee sens eeee weer e ree eeseseseseace Rieiehistne sts Sah gGo gy UOISSTULpY ce b el CORN Male da aaa eye etetehetssitee ** WOIsueg puv ‘Soat AA ‘SOTIRTEQ Oe TOOT cs ke eae ares toeeeeee teense wees suordraosqng jenuuy fe F 1/3 “OLS ‘0G “equmaaoyr Supua wax ay, buimp (spung gsnuz woul puodo) aunppuedug pun auoour fo yuauagny —_—_—_—_—_— Dodi Pols 9 LL PLLF QZ GG ieesteesttrreeeteeseeencensesenecneanres Hetereeseeresees QOIG TO OTRE fy 1 ipa bea oapserk tia aaa Mosisteitteitatedtel inte pieaienieisletaie's resis ‘gouryeq 00 GIL oC" chan Soa sonpeboaen saree «inhale ss MMs ateerats cies ‘+ gHOIyRUO 0 FI GSE a eee mecca tse e err e set ersn essere rene sss reer re seeees ove qy.sn0g 4040 G 61 SSL COC ee eos ere e ease ees OOOO OE anes rH eee EOF eeeeeerssegarsere® spuoprlalqy 0 0 Glg iieetetestes Hrneeneerestreettrerens gaopug Le ns a (or CTs ‘D [C FF ‘P 7S) F + oD g OL 16c0F _ ies ma 0 0. 00k F.: warhead rashes aT OREO Ze ueqodoao pr rT « = 8 Ol 16lOF “Te sorymmmuy “quep ted g mony ‘OLST Ane 07 dn syueursoauy ‘pung foyaay oufiquarogy - 1870.] Presents. 131 Presents received November 17, 1870. Transactions. Batavia :—Bataviaasch Genootschap van Kunsten en Wetenschappen. Verhandelingen. Deel 33. 4to. Batavia 1868. Notulen van de Algemeene en Bestuurs-Vergaderingen. Deel 4. Afl.2; Deel 5, 6,7. No.1. 8vo. Batavia 1867-9. Tijdschrift voor Indische Taal-, Land-, en Volkenkunde. Deel 16. Afi. 2-6; Deel 17. Afi. 1-6; Deel 18. Afi. 1. 8vo. Batavia 1866-68. Katalogus der Ethno- logische Afdeeling van het Museum. 8vo. Batavia 1868. Cata- logus der Numismatische Afdeeling. 8vo. Batavia 1869. The Society. Copenhagen :—Kongelige Danske Videnskabernes Selskab. Skrifter. 5 Rekke. 8 Bind, 6, 7; 9 Bind, 1. 4to. Ajébenhavn 1869. Over- sigt, 1868, No. 6; 1869, No. 3,4; 1870, No.1. 8vo. Ajébenhaun 1868-70. The Society. Dublin :—Royal Dublin Society. Journal. No. 39. 8vo. Dublin 1870. The Society. Konigsberg: — Konigliche physikalisch-okonomische Gesellschaft. Schriften. Jahrgang 8-10. 4to. Kénigsberg 1869-70. The Society. Haarlem :—Hollandsche Maatschappij der Wetenschappen. Natuur- kundige Verhandelingen. Deel 12, 24. 8vo. Haarlem 1824-44. Tweede Verzameling. Deel 5. Stuk 2; Deel 13, 20. C. H. Hoff- mann u. H. Weyenbergh, Die Osteologie und Myologie von Sciurus Vulgaris. W. F. R.Suringar, Algze Japonice. 4to. Haarlem 1850- 70. Archives Néerlandaises des Sciences Exactes et Naturelles. Tome VY. liv. 1-3. 8vo. La Haye 1870. The Society. Haarlem :—Musée Tayler. Archives. Vol. III. fase. 1. 8vo. Harlem 1870. The Museum. London :—British Museum. Hand List of Genera and Species of Birds, by G. R. Gray. Part 2. Supplement to the Catalogue of Shield Reptiles, by J. E. Gray. Part I. 4to. London 1870. Catalogue of Lithophytes, or Stony Corals, by J. E.Gray. 8vo. London 1870. Catalogue of the Fishes, by A. Giinther. Vol. VIII. 8vo. London 1870. Index and Guide to the Collection of Minerals. Guide to the Exhibition Rooms of the Departments of Natural History and Antiquities. Guide to the Autograph Letters, &. 8vo. London 1870. Catalogue of Prints and Drawings. Division 1. Satires. Vol. I. 1820-1689. 8vo. London 1870. The Trustees. Clinical Society. Transactions. Vol. III. 8vo. London 1870. The Society. Institution of Civil Engineers. Minutes of Proceedings. Vol. X XIX. © XXX. 8vo. London 1870. The Institution. Linnean Society. Transactions. Vol. XXVI. Part 4; Vol. X XVII. Te ae tao ae 132 Presents. [Nov. 17, Transactions (continued). | Parts 1&2. 4to. London 1870. Journal. Zoology, Vol. XI. No. 49. Botany, Vol. XI. Nos. 54, 55. 8vo. London 1870. Proceedings, Session 1869-70, pp. xxxili-exx. Additions to the Library. List. 8vo. The Society. Royal Agricultural Society. Journal. Second Series. Vol. VI. Part 2. 8vo. London 1870. The Society. Royal Institution. Proceedings. Vol. V. Part 7; Vol. VI. Parts1&2. 8yvo. London 1869-70. List of the Members, &c. The Institution. Royal Medical and Chirurgical Society. Medico-Chirurgical Trans- actions. Vol. LIII. Proceedings. Vol. VI. No. 6. 8vo. London 1870. The Society. 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Part 1. Bulletin. Vol. I., No. 1-12. @yo, Salem 1867-70. The Institute. Peabody Academy of Science. First Annual Report of the Trustees, January 1869. 8vo. Salem 1869. The American Naturalist. Vol. III. Nos. 1-12; Vol. IV. Nos. 1, 2. 8vo. Salem 1869-70. The Academy. Warwick :—Warwickshire Natural-History and Archeological Society. Annual Report. 1, 2, 5-16, 18, 25-34, 8vo. Warwick 1837-70. Proceedings of the Warwickshire Naturalists’ and Archeologists’ Field Club. 1865, 1868. 8vo. Warwick. The Society. Washington :—Smithsonian Institution. Smithsonian Contributions to Knowledge. Vol. XVI. 4to. Washington 1870. Smithsonian Mis- cellaneous Collections. Vol. VIII., IX. 8vo. Washington 1869. Annual Report of the Board of Regents for the year 1868. 8vo. Washington 1869. The Institution. 1870. | Presents. 133 Wellington :—New-Zealand Institute. Transactions and Proceedings. 1868-69. Vol. L., II. 8vo. Wellington 1869-70. The Institute. Journals. Australian Medical Journal. No. 108-112. 8vo. Melbourne 1870. . The Editor. Bulletin de Statistique ai oe Ville de Paris. Jan._May 1870. 4to. Paris. Mons. Chevreau. Zeitschrift fir Chemie. J ee 9-12. 8vo. Leipzg 1866-69. The Editors. Observations. Dublin :—Astronomical Observations and Researches made at Dunsink, the Observatory of Trinity College, Dublin. Part 1. 4to. Dublin 1870. | Dr. F. Brunnow. Leyton :—Astronomical Observations taken during the years 1865-69 at the Private Observatory of J. G. Barclay, Esq. Vol. II. 4to. London SLO: J. G. Barclay, Esq. London :—Meteorological Office. Quarterly Weather Report. Part 1. Jan.—March 1869. 4to. London 1870. Weather Reports. Jan. 1 to June 30, 1870. folio. London. Report of the Meteorological Com- mittee of the Royal Society for the year ending 31st December, 1869. 8vo. London 1870. The Office. Oxford :—Radcliffe Observatory. Results of Astronomical and Meteoro- logical Observations made in the year 1867. Vol. XXVII. 8vo. Oxford 1870. The Radcliffe Trustees. Brodie (Rev. P. B.) Practical Geology. 8vo. Warwick 1869. Sketch of the Lias generally in England. 8vo. Warwick 1868. The Author. Deslongchamps (Eugene E.-) Notes Paléontologiques. Vol. I. 8vo. Caen 1863-69. The Author. Duhamel (J. M. C.) Des Méthodes dans les Sciences de Raisonnement. Partie 4. 8vo. Paris 1870. The Author. Harris (George) The Theory of the Arts, or Art in relation to Nature, Civilization, and Man. 2 vols. 8vo. London 1869. The Author. Holland (T. J.) and H. Hozier Record of the Expedition to Abyssinia. 2 vols. 4to, and case of Maps. London 1870. The Secretary of State for War. Jardine (Sir Wm.), F.R.S. ‘Natural History and Illustrations of the Scottish Salmonidee. 12 plates in portfolio. General Sir Edward Sabine, K.C.B., P.R.S. Lubbock (Sir John), F.R.S. The Origin of Civilization and the Primitive Condition of Man, 8vo. London 1870. The Author. VOL. XIX. M 134 Presents. [Nov. 24, Métivier (Georges) Dictionnaire Franco-Normand ou Recueil des Mots particuliers au Dialecte de Guernesey. 8vo. London 1870. Dr. Hoskins, F.R.S. Poncelet (J.V.), For. Mem. R.S. Introduction a la Mécanique Industrielle physique ou expérimentale; troisicme édition, par X. Kretz. 8vo. Paris 1870. The Editor. Secchi (A.), For. Mem. R.S. Le Soleil. 8vo. Paris 1870. The Author. Tayler (William) The Popes of Rome, from the earliest times to Pius IX. a.d. 1870. 8vo0. London 1870. The Author. November 24, 1870. Transactions. Brinn :—Naturforschender Verein. Verhandlungen. Band VII. 1868. 8vo. Brinn 1869. _ The Society. Goteborg :—Kongl. Vetenskaps och Vitterhets Samhiille. Handlingar. Ny Tidsfoljd. X. Hiftet. 8vo. Goteborg 1870. The Society. London :—Institution of Civil Engineers. The Education and Status of Civil Engineers in the United Kingdom and Foreign Countries. 8vo. London 1870. ' ‘The Institution. St. Bartholomew’s Hospital. Reports. Vol. VI. 8vo. London 1870. The Hospital. 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Results of Astronomical Observations made in the year 1866, 1867, and 1868. 8vo. Melbourne 1869. Her Majesty’s Government in Victoria. Washington :—Bureau of Navigation. The American Ephemeris and 1870. | Appropriation of the Government Grant. 135 Observations (continued). Nautical Almanac for the year 1872. 8vo. Washington 1870. Tables of Harmonia, by HE. Schubert. 4to. Washington 1869. The Bureau. Bastian (H. C.), F.R.S. Facts and Reasonings concerning the Hetero- genous Evolution of Living Things. 8vo. London 1870. The Author. Helmholtz (H.), For. Mem. R.8. Die Lehre von den Tonempfindungen. Dritte umgearbeitete Ausgabe. 8vo. Braunschweig 1870. The Author. Huguet (H. A. B.) Exposé de Médecine Homceodynamique. 12mo. Paris 1869. The Author. Jones (Joseph) Suggestions on Medical Education. Introductory Lecture in the Medical College of Georgia. 8vo. Augusta 1860. Agricultural Resources of Georgia. Address before the Cotton Planters’ Conven- tion of Georgia at Macon. 8vo. Augusta 1861. Researches upon “‘ Spurious Vaccination.” 8vo. Nashville 1867. Chemical Analysis of Louisiana Rock-salt. 8vo. New Orleans 1869. Mollities Ossium. 8vo. Philadelphia 1869. Observations and Researches on Albinism in the Negro Race. 8vo. Philadelphia 1869. The Author. Luvini (Giovanni) Saggio di un corso di Fisica Elementare proposto alle scuole Italiane. 8vo. Torino 1868. The Author. Walenn (W. H.) Patents for Inventions. Abridgments of Specifications relating to Aéronautics, a.p. 1815-1866. 8vo. London 1869. The Compiler. A.—Account* of the appropriation of the sum of £1000 annually voted by Parliament to the Royal Society (the Government Grant), to be employed in aiding the advancement of Science. The present statement is im continuation of that already given up to April 5, 1855, in Volume VII. pp. 512-522. 1855. 1. To the Rev. F. Bashforth, for inquiries concerning Capillary RRUDEE MOM ans WL gees elk) che Mey inet en Alto dlg lhl) QUE a tenes Or 2eD0 2. To Dr. Miller, on behalf of the Kew Observatory, for the con- struction and verification of Standard Meteorological Instruments . 100 * By resolution of the Council of Dec. 15, 1870, it has been ordered that accounts of the Expenditure of the Government Grant, and of the sums granted from the Donation Fund, shall be published annually in the Proceedings, with the Report of the Anni- versary Meeting. 136 Appropriation of the Government Grant. 3. To Dr. Salter, for inquiries in Experimental Physiology .. 4. To Dr. Frankland, for continuation of his researches on Or- gano-Mietallie:Bodiés ) 0.02... 050.5 oh. ot ee 5. To Mr. Fairbairn, for experiments on the Explosions of Steam- poilerse........ Hae - 6. To Professor E. ioletineba oe coneinuies ie experimen on the Strength of Materials 3). 00.0... 0) 7. To Dr. Carpenter, for researches in Marine Natural History . . 8. To Mr. H. F. Baxter, for researches in Electro-Physiology.. 1856. 1. To Dr. Gladstone, for researches on Chemical Affinity 2. To Dr. Tyndall, for continuing researches in Magnetism. ... 3. To Mr. Cooper, for expense of printing the fourth and last volume of his Catalogue of Ecliptic Stars ...............0000- 4. To Dr. Harley, for continuing his researches on the Chemistry of Respiration 2)... id. eas : do. To Mr. Greville Williams, fore an geetionon of che Products of Distillation of Coal at low temperatures. . s 6. To Mr. Lockhart Clarke, for iimestieanione no the snteue of the Medulla oblongata and Pons Varolii of Man, and some of the Vertebrata. . fen Lo. Dr. Brown. Séquard, for researches on he vel proper of Muscles, Nerves, and the Spinal Chord . 8. To Professor William Thomson, for continue Ne Electrical MESCARE MES EE oc xe ee cote odds se bee cad) sot onan 1. 9. To Professor Eaton Hodgkinson, for continuing his experi- ments on the Strength of Materials ......5....-.-...-5 see 10. To Dr. Carpenter, for the prosecution of his researches on Narme Natural Tistory, .... . owe ss sont ence Soka, NO 11. To Professor William Thomson, for procuring Instruments for the observation of Atmospheric Electricity in Nova Scotia ...... 12. To Mr. W. R. Birt, for the purchase of a 4-inch Object- glass for observing the Physical Features of the Moon.. ....... 13. To Dr. W. A. Miller, for Apparatus for the investigation of CHE SPEChEUIN YS. LAO LEE One ieee eee, ee 1864. 1. To Mr. R. C. Carrington, towards defraying the cost of Print- ing and Publishing his Observations of Solar Spots ....... 2. To Mr. T. A. Malone, for investigating the nature af the Action and Results obtained in the Daguerreotype and Photographic EMROCEESES (AU oie. oe «oye, ee se, foe tas be Coreg |e le: oer 3. To the Rev. Dr. Robinson, for reducing a series of Anemo- BIEEIC TRCPISHEALLONS <. 4 cctece alas «je ocean de ths 2 eee Seer 4. To Mr. Gassiot (on behalf of the Kew Committee), for obtain- ing Copies of Magnetic Curves taken at Kew, for distribution .... Ditto, ditto, for procuring a self-recording Anemometer for ob- servations to be taken at the Island of Ascension................ 5. To Dr. Pavy, for Physiological Researches into the Stomach BM AaIVET) ates PE hoe. hgs Hadi oa tan Qt We. PRR ee 6. To Mr. F. Jenkin (on behalf of a Committee of the British | Association), to supplement Grants voted by the British Associa- tion for the construction of four Standard Electrical Instruments “meine Observatory at Kew (2... 0 aie 7. To Dr. Matthiessen, for further researches into Narcotine .. 8. To Mr. Schorlemmer, for investigations into the whole series pimwe so-called ‘Aleohol Radicals: woiniiewesiiik ohh de SR 9. To Mr. De La Rue, for continuation of Photoheliography at Mew mime prUAty A SDS 4/352 oh «aga nip he doko ote ania eee 10. To Dr. Richardson, for an Inquiry into the best means of Testorinespspended AMIMALION | 0): % 50> ninpt ine! sahe only eee 11. To Professor Tyndall, for researches on Radiant Heat as applied to: Molecular-Phiysies .... 5. s\. i... 3 heen feen eens 150 250. Appropriation of the Government Grant. 12. To the Rev. H. Tristram, for expenses of a Botanical Col- lector in the Expedition to the shores of the Dead Sea and adjacent 141 SDULLUUTEY 2 ofl eaten tole asic ub aa ee ac ai aaa erator eer Hiner £50 1865. 1. To Mr. De La Rue, for continuing the observations with the ner Photoheliograph to November 1865 . 100 . To Mr. Balfour Stewart, for igieoiine ate cost a alate aia etic Macmetie: © unvesm. <1) Seca ape ele ate 100 Ditto, for repair of Pendulums, and fitting a room at Kew EUs MOSCEVATIONS: 6 8. ree vidi to oi lige didn dues sie pa qelee my ectis © 200 3. To Dr. Frankland, for continuing his researches on the Syn- Bie=issorOncame COMPOUNIS.. 25... . 2. cess egile a ueeh pe aees 100 4. To Dr. Maxwell rane for continuing his researches on the Polyatomic Radicals . 50 5. To Mr. B.C. Quod, oy eaie Weisse’s s anak @cleene S Ae TIME MOM SLATS: cots «(co sonio7 gine cB ae Whale alent s.Sia drs Bee alee hee 90 6. To the Rev. C. Pritchard, for arranging and computing Tables for facilitating the construction of Aplanatic Object-glasses . 60 7. To the Rev. Dr. Robinson (on behalf of a Committee of the © British Association), for experiments on Submarine Fog-signals. . . . 100 8. To Dr. Falconer, in furtherance of a determination by Levelling of the exact depression of the Dead Sea (the amount to be placed at fae disposal of Col. Sir Henry James) 2.6.0. «2 sac velo os lee 6 100 9. To Professor Stokes, for determining, by means of pendulums, the Index of Friction of Gases and Vapours .................- 100 10. To Mr. F. Galton, for an Apparatus for verifying Sextants in connexion with Kew Observatory . 80 11. To Dr. Richardson, for canine Hig Inuit Sie the means of restoring suspended Animation. . 50 12. To Mr. G. J. Symons, for the salary e an Tess 6 be employed in collecting and classifying Rainfall Statistics ........ 50 13. To Mr. De La Rue, for continuation at Kew Observatory of Oiiservarians On SuM=spots .. cr 8 Nd. ses ee os he es epee eee we 150 14. To the Rev. G. C. ieee for Actinometrical Instru- tes ATC AW SEL VALTONS, ie )2, np0r 5) coer farieg e101 kp a eites eyes nh Sceloyravoneles a Ge 30 1866. 1. To Professor Stokes, for continuing his experiments on the Index of Friction of Gases:and Vapours...:::.2502.6253...65 2. 79 2. To Sir Henry James, for half the excess of the expense of levelling to determine the exact depression of the Dead Sea, over the sums granted by the Royal one a. and ean: paee Society for the purpose ....... EL. (8a hiaic VOL. XIX. N 142 Appropriation of the Government Grant. 3. To Mr. F. Jenkin, for the construction of a Standard Elec- trodynamometer ........ ee ak 4. Ditto, for the Eonstrction ve a Standard Condens or hee den-jar .. bo To Mr. ‘B. Stewart, Oe dele punt ie Ones CE the Heat observed ina Revolving Disk ;..0006.... 6 jens ss ie Cee 6. Ditto, for determining the Rate and Length of Kater’s In- reales Pemd@alun . Cold Stratum, 2». <= Cold See iP. E. Ue At the Poles (pp, pp) the cold stratum occupies the whole depth, from the surface to the bottom ; but as we pass towards the Equator we find it lying further and further down, its surface forming an inclined plane on which the warm stratum rests. The warm stratum, on the other hand, has its maximum depth at the Equator, and gradually thins-off towards the Poles.—This is just what would be expected on the hypothesis of a General Vertical Circulation (§ 124 et seq.); since in the Polar-Equatorial flow of the cold stratum its surface would be continually gaining heat by contact with the warm stratum above, so that its superficial portion would be (so to speak) progressively transferred to the warm stratum ; whilst, on the other * Prof. Wyville Thomson, in his Lecture on “ Deep-Sea Climates” (‘ Nature,’ July 28, 1870), has expressed the opinion that the cold stratum in the North Atlantic is derived rather from the Antarctic than from the Arctic basin. Putting aside the difficulty of accounting for a constant flow of Antarctic water into the Northern Hemisphere, without a corresponding owtflow, a strong argument against it may be drawn from the facts stated above. For if the co/d stratum have a Southern source, we should expect its own temperature to be lower, and its effects upon the superincumbent stratum to be more marked, the further sowth it is examined,—the contrary of which proves to be the case. 1870.] Deep-sea Researches. 19] hand, in the Equatorial- Polar flow of the warm stratum its lower layer would be gradually reduced in temperature by moving over with the cold stratum beneath*. Moreover as its surface would be exposed to a lower and yet lower Atmospheric temperature the further North it moves, each super- ficial layer as it is cooled will descend into the colder stratum, of which the thickness will be progressively augmented at the expense of that which overlies it. 83. The Third group of Bottom-temperatures, which includes those taken within the embouchure of the Strait of Gibraltar (Nos. 25-28, p. 220), presents some peculiarities which are worthy of notice, when taken in con- nection with the fact already stated as to the constant Temperature of about 55° found in the water of the Mediterranean at depths greater than 100 fathoms. For if we compare the Bottom-temperatures of Stations 25, 28, 29, 30, and 38, with those of Stations 31, 32, 33, and 34, we find in the former a distinct elevation above the latter. Thus at Stations 25 and 28 the temperature was 53°°5, at 374 and 304 fathoms respectively ; at Station 29 it was 55° at 227 fathoms; at Station 30 it was 52°7 at 386 fathoms; and at Station 58 it was 54° at 503 fathoms: whilst at Station 31 it was 50°°5 at 477 fathoms; at Stations 32 and 34 it was 50° at 651 and 414 fathoms respectively ; and at Station 33 it was 49°-7 at 554 fathoms. This difference seems fairly attributable to the influence of the undercurrent which is now known to carry out the warmer Mediterra- nean water to mingle with the colder water of the Atlantic, and which, after flowing over the ridge between Capes Trafalgar and Spartel (§ 69), may still for a time maintain its distinctness on the descending slope of the Atlantic basin. It would probably not be difficult to trace its further course by a sufficient number of observations on the Temperature and Spe- cific Gravity of the bottom-water to the west of the Strait ; and it would be very interesting thus to ascertain how far this undercurrent makes its way before blending with the general mass of Atlantic water.—If a detailed examination of the phenomena of the double current should be undertaken by the Authorities at Gibraltar, this point should not be neglected. 84. Density.—In order to determine the Salinity of the water of the At- lantic Ocean as a basis for comparison with that of the Mediterranean Sea, the proportion of Chlorine in 34 samples of the former, taken between Fal- mouth and Lisbon, was determined by Volumetric analysis. Of these sam- ples, 12 were of surface-water, 12 of bottom-water from various depths down to 1095 fathoms, and 12 of intermediate water. The results are expressed in Grammes per 1000 Cubic Centimetres of water. * It was long ago shown by Dr. Arnott, in his ‘Hlements of Physics,’ that if two layers of water originally of different temperatures, separated by a good conductor, move in contrary directions, they will gradually exchange temperatures; and this principle is now applied in the construction of Coolers for Breweries and Distilleries, in which a hot liquid which it is desired to cool is made to impart nearly all its heat to a cold liquid whose temperature it is desired to raise. 192 Messrs. Carpenter and Jeffreys on [Dec. 8, Surface-water. Intermediate water. Bottom-water. Average...... 19°94 19°85 19°75 Maximum.... 20°19 19°94 19°98 Minimum.... 19°81 19°70 19°46 It appears from these Analyses that there is a slight excess of Salinity in the suxface-water of the Atlantic, as had been previously observed by Forchhammer *; the excess, however, being so small as not to neutralize — the excess of Density which the deeper water derives from its lower Tempe- rature and from the Pressure of the superincumbent column. Five de- terminations of the Chlorine contained in samples taken at the same spot, from the Surface, and from 10, 25, 50, and 100 Fathoms, gave the follow- ing results :-— SUTideen Shs ies sa See 20°013 10 fathoms...... 19-909 DO UN AR an oe Ws 19:909 50S Fan 19-909 LOO SS Ae Be eee 19°805 A comparison of these seems to indicate that the excess of density, being limited to a mere superficial film, is entirely due to evaporation ; and the reason why this more concentrated film does not sink, as it does in the Mediterranean (§ 90), is that its excess of Salinity is so small, that even at the depth of 10 fathoms its effect on Specific Gravity is neutralized by the greater density arising from reduction of Temperature.—The differ- ence between the maximum and minimum, which in Surface-water is only 1-52nd part of the whole, and in Intermediate water only 1-83rd part of the whole, is in Bottom-water 1-38th of the whole; and the minimum of the whole series, namely, 19°46, presented itself in a specimen of Bottom-water taken from a depth of 994 fathoms. This proportion might have been presumed to represent the inferior Salinity of the Polar stream, from which the Temperature of the sample indicated its derivation, were it not that another sample from a depth of 1095 fathoms was found to yield 19°73, or nearly the average proportion, of Chlorine. Two samples, taken respectively from 700 and 322 fathoms, gave 19°63; and the maxi- mum of 19:98 occurred in a sample from 717 fathoms. These anomalies are somewhat perplexing, yet the whole range of variation is really very small. Similar anomalies presented themselves in the results of Dr. Frankland’s Analyses of samples of Bottom-water collected in the Cold area (Report for 1869, p. 489); for whilst the proportion of Chlorine in a sample (No. 64) taken from a depth of 640 fathoms, at a Temperature of 29°-6, was 19°88, that of the Surface at 49°-7 being 19:96, it was 20°14 in another sample (No. 54), which, though taken at little more than half the depth (363 fathoms), was shown by its Temperature to have been brought up * See his Memoir on the “ Composition of Sea-water” in the Philosophical Trans- actions for 1865, p. 247. 1870. | Deep-sea Researches. | 193 from the Polar stream, that of the Surface at 52°°5 being 20°17. Pos- sibly, as suggested by Dr. Forchhammer (/oc. ci¢.), the several parts of the Polar stream may vary in density, according to the amount of nearly fresh water which each may have derived from the icebergs that have liquefied in it. 85. Specific Gravity.—As the determination of Specific Gravity by obser- vations taken with the Hydrometer on board ship is open to two sources of error,—that of the instrument, and that of the reading (which, when the vessel is unsteady, cannot be precise),—we deem it safer to depend upon the more exact determination of the Specific Gravity of a smaller number of samples by means of the Balance, and to estimate that of others by the Chiorine-determinations. In this manner we arrive at a range of from 1:0261, the Specific Gravity of the sample of Bottom-water of minimum density, to 1:0269, the Specific Gravity of the sample of Surface-water of maximum density ; the average of all being 1:0265. This agrees very well with the results obtained by Forchhammer. TEMPERATURE AND COMPOSITION OF MEDITERRANEAN WATER. 86. Surface-Temperature.—With only two days’ exception, the range of the daily average Surface-temperature of the Mediterranean, between the 16th August on which we entered it, and the 28th September on which we quitted it, was between 73° and 79°. The increase at once experienced as we passed into it from Gibraltar Strait was extremely marked (§ 45); and this was maintained for the next two days. On the 19th, however, the average of the day fell from 72°°2 to 66°°9, the average of the Air being 69°-8; and on the 20th it was 68°°9, the average of the Air being 74°°3. On the first of these days we were crossing from the African towards the Spanish coast, and experienced very strongly the effect of the in-current on the movement of our vessel (§ 47); and it can scarcely be doubted that the low surface-temperature was due to the colder stratum introduced from the Atlantic. On the following day we were between Cape de Gat and Cartagena; and were still within the influence of the cold in-current, which is known to flow past Cape de Gat at the rate of about a mile per hour. On leaving Cartagena, we came into a surface-stratum of true Mediterranean water, as indicated by its temperature of 73°; and the daily average never afterwards fell below this. The greatest heat was experienced in the neighbourhood of the Tunisian coast, when for several days the average Surface-temperature was 78°. The average Temperature of the Air during the greater part of our Mediterranean Cruise was from 1° to 2° above that of the Sea; but during our return from Malta towards Gibraltar, between the 20th and 26th September, the temperature of the Air averaged about 3°°5 delow that. of the surface of the Sea, the former having fallen, while the latter remained nearly stationary until we neared the Strait of Gibraltar. As we approached VOL. XIX. R 194 Messrs. Carpenter and Jeffreys on [Dec. 8, it, a progressive reduction was observable, from 74°, which had been the average of several previous days, to 72°, with a further reduction to 71° when we entered Gibraltar Harbour. The scorching power of the Sun’s rays was often very strongly felt ; and we much regretted that we were not provi- ded with a Thermometer having a range sufficiently high to enable us to esti- mate the influence of direct solar radiation*, There can be no question that the effect of this radiation upon the surface must be to produce a rapid. eva- poration, especially when the air is dry. The difference between the Dry- and Wet-bulb thermometers averaged about 4°, but rose occasionally to above 8°; we could not, however, trace any relation between this difference and the Surface-temperature of the Sea. 87. Temperature of the Upper Stratum.—Finding that the reduction in Temperature with depth was so extremely rapid as to show that the direct influence of Solar radiation is limited to a comparatively thin stratum of surface-water, we took Serial soundings at three Stations, at intervals near enough to show the rate of diminution. The first of these Stations (Stat. 40), although the nearest to the Strait, seems to have been out of the direct influence of its cold in-current, which is shown very strongly in the second (Stat. 47) ; the third (Stat. 53) may perhaps be taken as representing most characteristically the thermal condition of the upper stratum of the water of the Mediterranean during the season of greatest heat :— I. II. III. ° Fahr. Diff. ° Fahr. Diff, ° Kahr. Diff. BMTHACE saa eco. 642 F400 69°5 ia 5. fathoms ...... 52 10°5 76°0(6°0 On, 69°3) 59°02. 71:0) a0 65015 B75 10 615{ 9 ag i 63:0} af elise Ae 60-0} a 40 D5 ee 2-0) oe 0-4 5773 0-6 Bile $s, rte cee 59°74 4. 55°3f 56-74 Ry eg a rare pil to. gagh OO. | eee Taking No. III., therefore, as the standard of comparison, we ob- serve that while the Thermometer fell only 1° in the first five fathoms, it fell 5° in the second five, and no less than 9°°5 between 10 and 20 fathoms, below which depth the reduction was very slow. In No. I., with a lower surface-temperature, the reduction in the first ten fathoms was nearly the same; but it was much less between 10 and 20, so that for depths between 20 and 50 it was between 3° and 4° higher than at corresponding depths in No, III.; at 100 fathoms, however, the two were brought to an almost precise accordance by the larger reduction which took place in No. I. between 50 and 100 fathoms. In No. II., on the other hand, the great * We learned from Colonel Playfair, the Consul General at Algiers, that whilst he was at Aden, a Thermometer with a blackened bulb having been laid upon a black surface, and exposed to the full glare of the Sun, had risen to 215°. 1870.] | Deep-sea Researches. 195 reduction showed itself in the uppermost stratum of 10 fathoms; but though the further reduction took place at a very slow rate, the tempera- tures at this Station were decidedly below those at the other two, down to 100 fathoms, at which there was not a difference of 1° among the three. 88. Bottom-Temperature.—The uniformity which showed itself in the Temperature of the bottom (see Table, p. 221), at all depths below 100 fathoms, was very remarkable. The /owesé bottom-temperature we anywhere met with was 54°; and this presented itself at a depth of 790 fathoms. The highest we anywhere met with was 56°5; and this presented itself in three instances, at depths of 266, 390, and 445 fathoms. But that the trifling elevation was not in any way dependent upon the smaller depth of these Soundings, was obvious from two considerations :—first, that our deepest sounding gave a temperature of 56° on a bottom of 1743 fathoms, whilst we found 55° at depths of 1456 and 1508 fathoms; and second, that the slight variations observable among the doffom-temperatures occurred also - between the temperatures taken at 100 fathoms. In fact, whatever the temperature was at 100 fathoms, that was the temperature of the whole mass of water beneath, down to the greatest depth explored. In that part of the Western basin of the Mediterranean which lies between Gibraltar and Sardinia, the bottom-temperature ranged between 54° and 55°5, the average being 54°-9, East of this, in the neighbourhood of Sicily, the bottom-temperature ranged between 55° and 56%5, the average being 55°°8. It was because we thought it possible that the slight excess of Bottom-temperature on this area might be due to Volcanic heat beneath, that we directed our homeward course by way of Etna and Stromboli, for the purpose of ascertaining if the near neighbourhood of a constantly active Volcano has any influence in raising the temperature of the bottom. No such influence, however, was perceptible; the Temperatures obtained at Stations 61 and 62,—namely 55°-7 at 392 fathoms, and 55°:3 at 730 fathoms,—being rather delow than above the average. 89. The remarkable contrast thus presented to the slow but continuous reduction of temperature encountered in the successive strata of Oceanic water in the great Atlantic basin, and to the sudden fall which presents itself as the Thermometer descends to its lower depths (§ 79), excites enquiry into the cause of the difference. It is now clear that no amount of surface- heat has power directly to affect the temperature of sea-water to a greater depth than 100 fathoms, the elevation of temperature it produces below 30 fathoms being very slight; and it seems also clear that the uniform temperature of from 54° to 56°°5 encountered below the 100 fathoms’ stratum, represents the permanent temperature of the great mass of water which occupies the Mediterranean basin. Now this mass is entirely cut off from the influe of the General Oceanic Circulation, the surface-inflow through the Strait of Gibraltar having no other effect than slightly to lower the general temperature at the western extremity of the basin. And the uniform permanent temperature of the mass of Mediterranean water may R 2 196 Messrs. Carpenter and Jeffreys on [Dec. 8, thus be considered as representing the mean temperature of the Earth in that region, slightly raised, perhaps, by a downward convection of heat from the surface in the manner to be presently described (§ 90). With such an allowance it corresponds closely with the determinations of the mean tempe- rature of the Crust of the Earth, made by sinking Thermometers into the eround tosuch a depth as to seclude them from the direct influence of Semmer heat or Winter cold, but not to bring them within the direct influence of the Internal Heat of the earth. Thus Quetelet found that a Thermometer sunk to a depth of 24 feet at Brussels showed an annual average of 53°°4, the range of variation being only 2°°5; and Bischoff found a Thermometer sunk to a depth of 36 feet at Bonn give an annual average of 51°, with a range of only 1°°5. The Temperature of deep Caves gives another set of data of the like kind, which accord very closely with the foregoing. Thus we have been informed by Mr. Pengelly that the temperature in the part of Kent’s Hole at Torquay which is furthest from its entrance varies but little from 52° throughout the year. ‘There is a cave in the island of ~ Pantellaria, lying between Sicily and the African Coast, which is reputed to be of “icy coldness;’’ but Lieut. Millard, of H.M.S. ‘ Newport,’ who has lately been making a careful survey of the Island, informed us that, although he felt it “very cold”’ on passing into it out of a very hot sun- shine, its actual temperature, taken by Thermometer, was 54°. And we have also learned on good authority that this is the temperature of the bottom of the deepest tanks in which water is stored up in Malta, provided that these are excavated (as is very commonly the case) be- neath the houses, or are in any other way secluded from the direct rays of the sun. 90. Now let it be supposed that the superficial stratum of the water of the Mediterranean had been cooled down by a severe winter to the uniform temperature of the depths below; we have to enquire in what manner it would be affected by the heating-power of the summer sun. ‘This, it is obvious, can be only exerted directly upon the actual surface; for the~ conducting-power of water is so small that very little downward trans- mission of heat would take place through its agency. Further, as the application of heat at the surface will render the superficial layer specifically lighter, no such convection will take place in the downward direction as takes place upwards when heat is applied at the bottom. But another agency comes into play in the case of Sea-water. The rapid evaporation produced by powerful solar radiation, especially when aided by the hot dry winds of Africa, occasions such a concentration of the surface-film, that, in spite of its elevation of temperature, it becomes specifically heavier, and descends,—to be replaced by a fresh layer. In this manner it will carry down an excess of heat, which diffuses itself through the subjacent layer, of course producing the greatest elevation of temperature in the stratum nearest the surface. ‘The continual repetition of this process through the hot season will carry the elevation of temperature further and further 1870.] Deep-sea Researches. 197 down; but so soon as the temperature of the Air falls much below that of the Sea, the surface-layer being cooled will become heavier and sink, and wil thus carry down cold instead of heat, so as to lower the temperature of the stratum below. In no instance, however, so far as we can learn, hag the surface-temperature of the Mediterranean ever been seen so low as 56°, even in midwinter. 91. That it is by this sinking of the surface-films successively concen- trated by evaporation that the Solar heat, which acts so powerfully on the Mediterranean basin during the summer, is transmitted downwards, appears certain from the fact, of which the particulars will be presently given, that the Salinity of the water of the Mediterranean is greater below the surface than a¢ the surface, instead of diminishing as it does in the Atlantic ($ 84); and we thus see how important an influence is exerted by that Salinity in diffusing the heat imparted to the surface through the waters beneath. In the great fresh-water lakes of Switzerland, the deeper water retains all through the year a temperature but little above 39°, the small excess being probably derived from the warmth of its bed; for the whole mass of water down to the bottom must be cooled to this degree in winter before any ice can form on its surface; and as the heating of the surface in summer makes all the water affected by it specifically lighter, none of it will descend and carry heat downwards, as it does in the Mediter- ranean. 92. Density.—The determination of the actual Salinity of the water of the Mediterranean basin, alike at the Surface and at various Bottom-depths, was one of the special objects of our inquiries ; for although various Ana- lyses had been previously recorded, they had been made upon samples of water which had been kept in bottles for a more or less considerable period ; and the depths from which those samples had been collected were not by any means the greatest known to exist in this basin.—The number of Chlo- rine-determinations of Surface-water was 25; and their Geographical range was from the Strait of Gibraltar to the edge of the Eastern basin (Station 60). A marked difference in density was observable between the Surface-waters of the Western and of the Eastern portions of this area ; for whilst those of the latter invariably showed a considerable excess in Salinity above the maximum of Atlantic water, that excess was so much reduced in some of the samples taken nearer to the Strait, as almost certainly to show that the surface-stratum there consists in great degree of Atlantic Water. Thus at Station 47, in which a like indication was given by the Tempera- ture of the Surface-water (§ 87), we found the proportion of Chlorine to be 20°46, or only 0°27 above the maximum we had encountered in Atlantic water ; and when we crossed to the neighbourhood of the opposite Algerine Coast (where, however, the density of the Surface-water was probably re- duced by the entrance of River-water), we found the proportion of Chlo- rine as low in one case as 19°69, and in another as 19°99. When ap- proaching the Strait on our return voyage, we took a series of five samples 198 Messrs. Carpenter and Jeffreys on : [ Dec. 8, for the purpose of testing the reality of this difference ; and we found the proportions of Chlorine to be respectively 20°77, 20°67, 20°56, 20°51, and 20°47. The mean of these five determinations, together with the one pre- viously taken at Station 47, but excluding the two taken on the coast of Algiers, is 20°57; and the mean Specifie Gravity was 1:0274. On the other hand, at the Sicilian end of the basin, where the water was that of the Mediterranean proper, the mean of ten Chlorine-determinations was 21°05, with a corresponding Specific Gravity of 1:0280. The maximum of Chlorine was there 21°32, with Specific Gravity 1-0264 ; and the minamum 20°77, with Specific Gravity 1:0277. The combination of these 16 obser- vations gives a mean of 20°87 for the Chlorine, and 1:0278 for the Specific Gravity, of the Surface-water of the Mediterranean generally *. 93. The number of Chlorine-determinations of Bottom-water taken in the proper Mediterranean basin, at depths between 207 and 1700 fathoms, was 20. They show a general excess of Salinity over the Surface-water, the mean of the whole being 21°38 (as against 20°87), with a maximum of 21°88 (Sp. Gr. 1:0292) and a minimum of 21:08 (Sp. Gr. 10281). On grouping them into three Series according to their depth, we arrive at a curious result :— Fathoms. Chlorine. Sp. Gr. 200 to 400, Mean of 7 observations...... 21°53 | We02Se 400 to 800, ,, Zi 33 ssc SC 1:0285 1300 to 1700, _ i, 6 5 ene OF 1 0283 94. Thus it appears that the excess of Salinity is greatest in the shallower water, and that it gradually diminishes with the depth. Thisis also shown most strikingly by comparing the sample taken from the least depth (207 fathoms) with that taken from the greatest depth (1703 fathoms) ; for it was the former that showed the maximum of 21-88, and the latter that showed the minimum of 21-:08.—Now this fact, though at first unex- pected (since we had supposed that the heaviest water would gravitate to the greatest depths), seems not difficult to account for, if we consider the mode in which the concentration of the surface-film will be likely to affect the water below. For it can be shown experimentally, by pouring a strong saline solution tinged with colour upon the top of a weaker colour- less solution, that the former will in the first instance sink “bodily,” but will gradually impart its excess of salt to the liquid through which it falls ; the descent of the coloured stratum becoming slower and slower, and its * This mean accords closely with that of 20:845 obtained by Prof. Forchhammer from his examination of samples collected at different times and by different persons from various parts of the surface of the Mediterranean (Phil. Trans. 1865, p. 252). His maximum of Chlorine, 21:718, was higher than ours; but this seems to have been an exceptional case; and the sample may have undergone some concentration in keeping. On the other hand, his minimum was lower, being only 20:16 ; but this sample, having been taken in the Strait of Gibraltar, contained a large proportion of Atlantic water. 1870. ] Deep-sea Researches. 199 colour being more and more imparted to the general mass of the liquid. The proportion of salt will in time be made uniform throughout the whole column by ‘diffusion.’ Now it is obvious that if each column rests (so to speak) on its own base, the degree in which the Salinity of the whole mass is raised by the addition of a more concentrated solution will depend ceéeris paribus upon its height; and thus where the depth of the Mediterranean basin is only between 200 and 400 fathoms, we should expect the Specific Gravity of its water to be more raised by the successive concentration of its surface-films, than where the depth ranges from 1300 to 1700 fathoms. 95. Since this proves actually to be the case, the further conclusion appears justifiable—that there is an extremely small amount of movement in the abyssal waters of the Mediterranean basin. The uniformity of Temperature throughout the whole of it, and the restriction of seasonal changes in temperature to its upper stratum, will prevent it from being subjected to any thing like the vertical circulation which is produced in the great Oceanic basins by the antagonistic action of Heat and Cold on the Equatorial and Polar areas (§ 125). And from any horizontal dis- placement they would seem altogether excluded by the depth at which they lie; for the action of winds cannot disturb more than that compa- ratively superficial stratum which is affected by the Gibraltar current. The infiow of lighter surface-water through the Strait, and the outflow of denser water from the comparatively shallow stratum of the neighbourhood, will probably produce no change whatever at depths greater than 500 fathoms. And the same may be said of the supply of fresh water brought in either by rain or rivers; for this will at once go to make up the loss produced by surface-evaporation ; and whilst helping to maintain the purity of the upper stratum inhabited by fishes &c., will do nothing for the waters of the abyssal depths. If these waters were continually subject to horizontal displacement, it might be expected either that the heaviest water would gravitate to the greatest depths, or that the density of the entire contents of the deeper portion of the basin would be equalized ; neither of which happens. On the contrary, as just shown, the density varies with the depth in so marked a degree, as to indicate that the water in each part of the basin retains its distinctness from the rest through long - periods of time. 96. Solid Matter in Suspension.—The water of the Mediterranean is di- stinguished from that of the Atlantic, not only in the larger proportion of Saline matter which it holds in solution, but also in having diffused through its whole mass, in a state of suspension, particles of solid matter in an ex- tremely fine state of division. This statement may seem strange to those who are familiar, either by personal observation, pictorial representation, or verbal description, with the (apparently) clear deep blue of the Mediter- ranean Sea. But the two phenomena will be presently shown not only to be compatible, but to stand to each other in the relation of cause and effect. 200 Messrs. Carpenter and Jeffreys on [ Dec. 8, - 97, Our attention was drawn to this point, in the first instance, by finding that the bottom-water brought up by the Water-bottle was nearly always turbid, and that this turbidity was with difficulty removed by fil- tration, The bottom-water brought up from sandy or gravelly bottoms is always clear; and though that which was brought up from the area covered by the “Atlantic mud”’ was often turbid, it was readily cleared by passing through filtering-paper, the deposit on which was found to consist of very minute Globigerine, which had been apparently floating in the stratum immediately above the Sea-bed. As the clearing of the Mediterranean water was requisite for our Chlorine-determinations, it was passed twice or thrice through the filter, and the solid matter left upon the paper consisted entirely of Inorganic particles of extreme minuteness. Now it is a fact well known to Chemists and Physicists, that the length of time required for the deposit of a precipitate increases with the fineness of the division of its particles, notwithstanding that the material of which they are composed may be of very high Specific Gravity. Thus it was shown by Faraday that precipitates of Gold may not subside for a month ; and Mr. Babbage has calculated that, in the case of lighter substances, a period of hundreds of years may be required for the gravitation of very finely divided particles through a considerable mass of fluid. 98. Taking into account, therefore, that the deep waters of the Medi- terranean are not only cut off from the General Oceanic Circulation, but that they are almost entirely destitute of vertical circulation amongst themselves (§ 95), it may be fairly considered that the perceptible turbi- dity of the bottom-water is due to the imperceptible diffusion of the same finely divided matter throughout the entire mass of superincumbent water. And that this is really the case, is shown by two different methods of proof. We learned from the Engineer of the Peninsular and Oriental Company’s Steam-ship by which we proceeded to join the ‘ Porcupine’ at Gibraltar, that the deposit removed from the boilers after working in the Mediterranean differs from that left by Atlantic water, not only in its larger proportion of sa/¢, but in having a very finely divided mud diffused through it, which is, of course, derived from the evaporation of surface- water. The result of this large-scale experiment harmonizes exactly with that of Prof. Tyndall’s examination of a small sample of the surface-water of the Mediterranean by the Electric light; for he found it to be highly charged with minute particles in suspension, as is also the water of the Lake of Geneva. And he has further shown that it is in each case to the presence of these particles that we are to attribute the peculiar intensity of the blue colour by which both these waters are characterized *. * See ‘Nature,’ Oct. 18, 1870.—We may take leave to mention that the same idea of the agency of the suspended particles in intensifying the blue colour of the water had previously occurred to ourselves, and had been made the subject of conversation on our voyage home, the probable community of the source of the suspended particles in the Mediterranean and the Lake of Geneva respectively having especially presented 1870. ] Deep-sea Researches. 201 - 99. But further, when we come to enquire into the source of these sus- pended particles, the progressive subsidence of which gives rise to the fine muddy deposit that covers all the deeper parts of the Mediterranean, we find that (so far, at least, as the Western basin is concerned) they have been in all probability brought down into it by the Rhone. The upper part of that river, as is well known, is constantly transporting a vast mass of sedimentary matter into the Lake of Geneva; and while the deposit of the coarser particles of the sediment at the upper end of the Lake is causing a progressive formation of alluvial land, the water which passes off at the lower end, though apparently clear, is still charged with particles ina finer state of division. ‘‘ Scarcely,”’ says Sir C. Lyell*, “has theriver passed out of the Lake of Geneva, before its pure waters are again filled with sand and sediment by the impetuous Arve, descending from the highest Alps, and bearing along in its current thé granitic sand and impalpable mud annually brought down by the glaciers of Mont Blanc. The Rhone after- wards receives vast contributions of transported matter from the Alps of Dauphiny and the primary and volcanic mountains of Central France ; and when at length it enters the Mediterranean, it discolours the blue water of that sea with a whitish sediment for the distance of between six and seven miles, throughout which space the current of fresh water is percep- tible.”—Thus the Western basin of the Mediterranean stands in the same relation to the lower part of the Rhone and to the tributaries which dis- charge themselves into it, that the Lake of Geneva does to its upper part. And a like universal diffusion of fine sedimentary particles through the Eastern basin is probably effected by the transporting agency of the Nile. 100. The very slow, but constant, subsidence of these minute sedimen- tary particles, then, is the source ofa large part of the material of that fine tenacious Mud which, mingled with a larger or smaller proportion of Sand, partly calcareous and partly siliceous, constitutes the deposit at present in progress on the deeper parts of the Mediterranean sea-bed. The source of the Caleareous sand, which is itself in a state of very minute subdivision, is probably to be found in the abrasion of the Calcareous Tertiaries which form the shore-line round a large part of the Western basin. This abra- sion is specially noticeable at Malta, where, for the security of the fortifi- cations, it has has been found necessary to check it by artificial means. The singular barrenness of this deposit in regard to Animal life forced itself upon our attention during the whole of our dredging-operations in the Mediterranean ($§ 48-52) ; and whilst disappointed as Zoologists in not meeting with the novelties we hoped to encounter, we venture to hope that itself to us: and it was with great satisfaction, therefore, that we found our notion so fully confirmed by Prof. Tyndall’s investigations; whilst it was not a little interesting to him to find that our independent inquiries had led us to affirm the presence of these suspended particles through the whole mass of Mediterranean water, and to attach so much importance to the fact in its Geological and Biological relations. * Principles of Geology, 10th ed. vol. i. p. 427. 202 Messrs. Carpenter and Jeffreys on [Dec. 8, the negative result of our sedulous investigations may have an important Geological bearing. 101. It will be borne in mind that our previous researches have fully demonstrated the fact that the Depth of from 600 to 1200 fathoms is not per se inconsistent with the existence of a varied and abundant Fauna; and that the reduction which shows itself at from 1200 to 2435 fathoms seems — to depend as much on depression of Temperature, as on increase of Depth. Hence it was fairly to be expected that a varied and abundant Fauna— probably containing a number of Tertiary types supposed to have been © long extinct—would have been found between 500 and 1500 fathoms, on a bottom of which the temperature seems never to fall below 54°. Now the question as to the cause of the deficiency of Animal Life on this bottom naturally connects itself with the old Geological difficulty, of which the inquiries of Prof. Edward Forbes were long supposed to afford a satisfactory solution ; viz. the existence of vast thicknesses of sedimentary strata, almost or entirely destitute of Organic Remains. The explanation which has been accepted for many years,—that these deposits were formed in Seas too deep to allow of the existence of Animals on their bottom,— having been now shown to be untenable, the old difficulty recurs; and it is obvious that if it can be shown that a condition prejudicial to Animal Life now prevails on the Mediterranean bottom, which also prevailed when other azoic deposits were formed, a great step will have been gained. Such a condition is to be found—we are disposed to think—in the turbidity of the bottom-water. All Marine animals are dependent for the aeration of their fluids on the contact of water either with their external surface, or with special (branchial) prolongations of it. Now if this water be charged with suspended particles of extreme fineness, the deposit of these particles upon the respiratory surface will interfere with the aerating process, and will tend to produce asphyxia. This is not a mere hypothesis. It is well known that Oyster-beds cannot be established in situations to which fine mud is brought by any fluvial or tidal current. And our Colleague Mr. Jeffreys, when dredging some years ago in the neighbour- hood of Spezzia, having on one occasion passed a little out of the Bay, from a sandy bottom rich in Animal life to a muddy bottom (this mud being doubtless a part of the Rhone deposit), without any considerable increase of depth, was forcibly struck by the barrenness of the latter. 102. It will be for Geologists to say how far this explanation can be applied to the case of the azoic sedimentary deposits of former epochs. One very notable case of the kind has been communicated to us by Dr. Duncan, that of the Fleisch, a stratum not less than 6000 feet thick, extending from Mont Blanc to the Styrian Alps, which must have been deposited in the condition of extremely fine arenaceous mud, and in which there is an almost entire absence of Fossils. We are disposed to believe, also, from the results of such inquiries as we have been able to make, that the extremely fine Calcareous sandstone of Malta, though reputed to be 1870.] . Deep-sea Researches. 203 rich ia Fossils, will be found to contain these fossils, for the most part, in its coarser beds; which were probably deposited in shallower waters, like those which we found rich in Animal life along the shores of the Mediterranean. ‘The extremely fine stone that is used for carved work,— so entirely wanting in “ grain” that carvings executed in it look like casts in Plaster of Paris,—contains, we were assured, few fossils except Sharks’ teeth, which, of course, dropped into it from above. We commend this enquiry to the attention of Maltese Geologists, as one having an impor- tant bearing on the solution of a problem of the highest interest. 103. There is another condition, however, which may be not less potent in restraining within very narrow limits the Animal Life of the deeper parts of the Mediterranean Basin,—namely, the stagnation produced by the almost entire absence of Vertical Circulation. In the great Oceanic ba- sins, if our doctrine (§ 124 e¢ seq.) be correct, every drop of water is in its turn brought to its surface and exposed to the purifying influence of prolonged exposure to the air. From this movement, the water of the Mediterranean. may be said to be virtually excluded; and, as has been already shown (§ 95), the deeper part of the basin has no Circulation of its own, either horizontal or vertical, which will have the effect of bring- ing its water to the surface. It is difficult, im fact, to conceive of any agency that can disturb the stillness of the abyssal depths of a basin which is completely shut in by a wall that rises more than 10,000 feet from its bottom. How far this affects the condition of such depths, in respect to the diffusion of the Organic matter and the Oxygen required for the support of Animal life, must be a matter of future inquiry. GIBRALTAR CURRENT. 104. The term “Strait of Gibraltar” is usually applied to that space between the coast-lines of Spain and Morocco which is bounded on the west by Capes Trafalgar and Spartel, and on the east by the two * Pillars of Hercules,’—namely Europa Point, which forms the southern extremity of the Rock of Gibraltar, and Jebel Musa or Apes Hill on the Barbary side. As Admiral Smyth justly remarks*, however, we may cor- rectly include in the Strait the whole of that funnel-shaped entrance from the Atlantic, of which the western boundary is formed by a line from Cape St. Vincent on the north to Cape Cantm on the south, the whole of the water within this entrance being affected by the surface-draught into the Mediterranean. It was considered by Major Rennell that there is a general “set.” of Atlantic water between Lat. 30° and 45° N., and from 100 to 130 leagues off the land, towards the entrance of the Strait, the rate of movement being as much as from 14 to 17 miles per day. This estimate, however, is regarded by Admiral Smyth (Joc. cit.) as excessive; although he thinks that such an indraught may possibly occur during the long pre- * The Mediterranean, p. 158. 204 Messrs. Carpenter and Jeffreys on [ Dec. 8, valence of particular winds. We have been informed by Admiral Onymaney that, according to his own experience, the zmse¢ is most considerable towards the African coast, while the oufset occasionally observed (§ 106) is most decided on the Northern coast ; and this statement derives very remarkable confirmation from the Thermometric observations already detailed. For these show that the lower temperature of the zm-current is specially notice- able near Cape Spartel (§ 73); whilst the higher temperature, which is traceable westwards along the Spanish and Portuguese coasts as far as Cape St. Vincent, and there suddenly falls to the ordinary standard of the Atlantic, seems to be derived from an efflux of the Mediterranean water (§ 75). 105. The length of the narrower portion of the Strait (see Chart II.), sometimes distinguished as the Gut, is about 35 miles. __Its width, which is about 22 miles between Capes Trafalgar and Spartel, gradually diminishes to somewhat more than 9 miles between Tarifa and Alcazar point; and then increases until it reaches 12 miles between Gibraltar and Ceuta, east- ward of which the Strait terminates abruptly in the wide basin of the Medi- terranean. The deepest portion of the Strait is at its eastern extremity ; its depth between Gibraltar and Ceuta reaching 517 fathoms, and averaging about 300 (Section c p.). From this the bottom gradually but irregularly slopes upwards (Section a B) as far as the western extremity of the Gut, where the shallowest water is to be found. The northern half of the channel across the section between Capes Spartel and Trafalgar (Section & F) scarcely anywhere exceeds 50 fathoms; whilst its southern half does not seem anywhere to reach 200, and may be considered to average 150 fathoms. On the Atlantic side of this ridge the bottom gradually slopes downwards, until it reaches, at 40 miles westward, a depth about equal to that which it has between Gibraltar and Ceuta. This ridge, therefore, constitutes a kind of marine “ watershed,” separating the Inland basin of the Medi- terranean from the great Oceanic basin of the Atlantic. 106. Through the central part of this Strait a current almost invariably sets eastward, or from the Atlantic into the Mediterranean. This current is most rapid in the narrower part of the Gut, where the znflow usually has a rate of from two to three miles an hour; this rate sometimes rising to four miles, or even occasionally (as stated by Gibraltar pilots to Admiral Smyth) to five; whilst the current is sometimes so reduced in speed as to be scarcely perceptible, even giving place (though very rarely) to a con- trary movement or outflow from the Mediterranean towards the Atlantic. These variations are partly due to Tidal influence, which is here very de- cided, and which may either concur with or oppose the general current. When the tide is flowing, its motion 1s westwards, or in opposition to the current; and at spring-tide this motion may be sufficiently powerful to check the current, or even to reverse its direction for a short time. When the tide is ebdzng, on the other hand, its motion is eastwards, or in the direction of the current ; and it is to the ebb of spring-tides that the occa- sional augmentation in the rate of the current to 5 miles an hour is probably 1870. ] Deep-sea Researches. 205 attributable. These effects will, of course, be most marked when the tidal movement is augmented by a strong wind in its own direction *.—The constant current does not occupy by any means the entire breadth of the Strait. In its narrowest part the rapid central in-current is said by Admiral Smyth not to average more than 4 miles in width; and on either side the stream when moving inwards is usually much less rapid, its rate, indepen- dent of tide, being about 1 mile per hour in the neighbourhood of Tarifa, and 2 miles an hour on the coast of Africa. These lateral currents are much more affected than the central current by the Lunar tide, which produces a complete periodical reversal of them; the flood at springs run- ning westwards off Tarifa at the rate of from 2 to 3 miles per hour, whilst even at neaps it runs westwards at 1 mile per hour. The ebb, on the other hand, concurs with the general current, and augments both its volume and its rate. Thus, when the water is falling, the whole stream is running eastwards ; but when it is rising, the tide on either shore sets westwards. By taking advantage of this periodical westerly flow in the lateral streams, it is possible for sailing-vessels to make their way outwards + in opposition to a continued westerly wind. 107. The rate of the general in-current diminishes immediately that it discharges itself into the Mediterranean basin, over the surface of which it seems to spread itself, in virtue of its lower Specific Gravity (§$ 92). But the influence of its motion is sensibly experienced along the Spanish Coast as far as Cape de Gat, and along the African Coast even as far as the Bay of Tunis,—its force and direction, however, being greatly affected by the prevalent winds. | 108. Various hypotheses have been put forward at different times to ac- count for this continual influx of Atlantic water into the Mediterranean. The motion of an undercurrent flowing in the opposite direction was very early suggested by Dr. Smith{; but he did not attempt to show in what way motion is given either to the surface inflow or to the deep outflow. Quite recently the extraordinary hypothesis has been seriously put forward, that the influx through the Strait may be due to a gradual depression of the bottom now going on§. The explanation usually received is that first offered by Dr. Halley||, who attributed it to the excess of evaporation from the surface of the Mediterranean Sea over the whole amount returned to its basin either directly by rainfall or by the rivers which discharge themselves into it; so that the level would be progressively lowered, if not kept up by an inflow from the Atlantic. The obvious objection to this explanation is, that as the water which passes off by evaporation leaves its Salt behind it, and as the water which enters through the Strait is * Admiralty Sailing Directions, p. 309. + See Admiral Smyth’s ‘ Mediterranean,’ p. 176. ¢ Philosophical Transactions, vol. xiv. p. 364. § Mr. George Maw in Geological Magazine, December 1870, p. 550. || Philosophical Transactions, vol. xvi. p. 866. 206 Messrs. Carpenter and Jeffreys on [Dec. 8, charged with the ordinary proportion of salt, there must be a progressive increase in the density of the water of the Mediterranean until it reaches the point of saturation. This objection has been met by another hypo- thesis, viz. that although the surface-water of the Mediterranean shows very little excess of density, there may be a great increase in the propor- tion of salt held in solution in the waters of its abyssal depths; and it has even been surmised that a deposit of salt is taking place on its bottom. 109. This hypothesis seemed to derive support from the analysis made by Dr. Wollaston in 1828*, of a sample of bottom-water brought up by Admiral Smyth from a depth of 670 fathoms, at a point about 50 miles within the Strait; which analysis gave the extraordinary percentage of 17°3 parts of Salt, with a Sp. Gr. of 1°:1288,—the proportion of Salt in ordinary sea-water being about 3-5 per cent., and its usual Sp. Gr. about 1027. But as Dr. Wollaston’s analyses of two other samples of Mediter- ranean water, taken respectively from depths of 450 and 400 fathoms, at distances of 680 and 450 miles eastward of the Strait, showed that their density but little exceeded that of ordinary sea-water, it was pretty clear that the first result was anomalous, and that in whatever way it was to be accounted fory, it did not represent the general condition of the deep water of the Mediterranean. (See §§ 43, 44.) 110. The inquiries detailed in the previous Section of this Report have conclusively shown (1) That there is a general excess of Salinity in the water of the Mediterranean over that of the Atlantic; (2) That this excess does not pass beyond very narrow limits; (3) That it is least in surface-water the proportion of salt in which is only about 4°7 per cent. above that contained in the surface-water of the Atlantic; (4) That it is greatest in bottom-water the proportion of salt in which may reach about 9 per cent. above that contained in the bottom-water of the Atlantic, this last not being more—and apparently somewhat Jess—dense than the surface-water of the same ocean. Our inquiries were almost entirely limited to the Western basin, in which bottom-water of the highest density seemed to prevail at the shallower depths ($93). The single sounding which was taken in the Eastern basin, at a depth greater than any else- where reached, gave us a sample of which the excess was 6°7 per cent. 111. From these results it seems a justifiable inference that the evapora- tion from the water of the Mediterranean basin is in excess of the amount of fresh water returned into it, occasioning an increase of its density; but that this increase, notwithstanding the constant influx of salt water from the Atlantic, is in some way kept in check, probably through an efflux of the denser water by an undercurrent, as originally suggested by Dr. Smith in 1673. This is the view adopted by Sir John Herschel (Physical Geo- graphy, 1861, p. 28); and it has been considered to derive support from * Philosophical Transactions, 1829, p. 29. + It was suggested by Admiral Smyth (‘ Mediterranean,’ p, 131) that a brine spring might have been struck upon. 1870.] . 3 Deep-sea Researches. 207 accounts that have been recorded of vessels sunk in the narrower part of the Strait having floated up near Tangier*. But to these accounts no great importance is assigned by Admiral Smyth, who seems inclined to attribute the occurrences—if they really took place as narrated—to the action of the lateral Surface-outflow. 112. The only objection that has been advanced, so far as we are aware, to the hypothesis of a westerly undercurrent, is based on the existence of the comparatively shallow ridge which (as already stated) crosses the western end of the Gut between Capes Trafalgar and Spartel. The exist- ence of this ridge, in the opinion of Sir Charles Lyell f, ‘“‘ has dispelled the idea which was once popular that there was a counter-current at a consi- derable depth in the Straits of Gibraltar, by which the water which flows in from the Atlantic is restored to that ocean.’?—But the validity of this objection has been disputed, and we think successfully, by Captain Maury, who, after citing many cases in which a deep current comes up to near the surface, concludes as follows :—‘‘ To my mind the proofs derived from rea- son and analogy are as clear in favour of this undercurrent from the Me- diterranean, as they were in favour of Leverrier’s planet before it was seen through the telescope at Berlin’’§. 113. The analogy of the Red Sea and the incurrent through the Strait of Babelmandeb, which is adduced by Capt. Maury in support of this view, is a very cogent one. The evaporation from the Red Sea is well known to be enormous, its annual amount being estimated by Dr. Buist as equal to. a sheet of water eight feet thick, corresponding in area with the whole ex- -panse of that sea. Of the whole amount of fresh water thus drawn off, scarcely any is returned either by rivers or rains. But the level is kept up by a strong current that continually sets in through the Strait of Babelmandeb; and as this current brings in salé water, there would be a continual and very rapid accumulation of salt in the trough of the Red Sea if the denser water were not carried off by an outward current beneath. Now since all the observations hitherto made upon the density of the water of the Red Sea show it to be very little greater than that of the Indian Ocean ||, there would seem no escape from the conclusion that such a re- verse undercurrent must really exist. 114, We shall now present, in a concise and connected form, the General Results of the inquiries we have ourselves made to determine this ques-° tion; the particulars having been detailed, as they presented themselves, in the preceding Narrative. These results were of a twofold character. It was our object, (1) to detect if possible by mechanical means any movement which may be taking place in the lower stratum of water in opposition to * Philosophical Transactions, vol. xxxiii. p. 192. Tt Mediterranean, pp. 154-157. ¢ Principles of Geology, 10th edit. vol. i. p. 563. § Physical Geography of the Sea, 1860, pp. 194-196. || Transactions of Bombay Geographical Society, vol, ix. p. 39. 208 Messrs. Carpenter and Jeffreys on [ Dec. 8, the surface inflow; and (2) to determine, by the Temperature, the Specific Gravity, and the Composition of samples of water taken up at different points and from different depths, whether they had been drawn from the Atlantic or from the Mediterranean basin.—The mechanical method was entirely devised and carried out, with the practical ability for which he is eminently distinguished, by our excellent friend Staff-Captain Calver (see § 37). The physical and chemical observations, which were made under our own direction, gave results which harmonize completely with those of the mechanical, where both could be employed together; and supply a deficiency which the impossibility of applying the mechanical test on the uneven bottom of the shallow ridge would otherwise have left, in the proof of the outfiow of Mediterranean water over it. 115. Our investigations were first made in the mid-stream between Gibraltar and Ceuta, at nearly the narrowest part of the Strait, where its depth exceeds 500, fathoms (Chart II. Section c p). The decided retarda- tion of the boat by the ‘‘ current-drag’’ at 100 fathoms in both sets of experi- ments (§§ 40, 62) showed that the in-current at that depth has less than half the velocity of the surface-current. When the “ current-drag”’ was lowered to 250 fathoms, there was in the First set of experiments simply a further increase of retardation, the boat being kept almost in a stationary position : we felt justified, however, in inferring that the strain of the “ current-drag ”’ could not have so nearly neutralized the action not only of the surface- current, but also of the wind, upon the boat from which it was suspended, if it had not been itself acted on by a counter-current. And this view derived very strong confirmation from the evidence afforded by the Tem- perature, the Specific Gravity, and the Density of the water in the 250 fathoms’ stratum. For, in the first place, the surface-temperature being 66°, and the temperature at 100 fathoms having fallen to 55°-7, no further reduc- tion showed itself below that stratum ; the water at 250 fathoms, like the bottom-water at 517 fathoms, having exactly the same temperature as the water at 100 fathoms. This, as we have seen, is the uniform rule in the Medi- terranean, whilst far otherwise in the Atlantic. Further, the Specific Gravity and the proportion of Salt in the water at 250 fathoms indicated a density which no Atlantic water possesses, and which was not exceeded in any sample obtained from the Mediterranean. There could be no question, ‘therefore, that the stratum at 250 fathoms must be Mediterranean water ; so that, if not absolutely stationary, it must be moving westwards. Now this westerly movement was distinctly demonstrated in our Second set of experiments, by the motion of the boat from which the “ current-drag”’ was suspended (§ 62); and since the observations on the Temperature, Specific Gravity, and Salinity of the water in this stratum, which were then repeated, gave results almost precisely identical with those made on the previous occasion, it seems fair to conclude that there was a westerly current in this stratum in the First, as well as in the Second instance, though its effect on the current-drag was masked by the stronger antago- 1870. ] Deep-sea Researches. 209 nistic forces acting on the boat.—The same observations apply to the 400 fathoms’ stratum. In the First set of experiments, the boat moved with the surface-current, but at little more than @ quarter its rate; and this retardation, taken in connection with the distinct Physical and Chemical indications that the 400 fathoms’ stratum was Mediterranean and not Atlantic water, might fairly be taken as evidence that the force acting on the “ current-drag”’ was antagonistic in its direction to the surface-forces acting on the boat, though less powerful than in the 250 fathoms’ stratum. This inference also was justified by the results of the Second set of experi- ments (§ 62), which showed us the boat carried westwards, though at a less rate than when the “ drag’’ hung in the 250 fathoms’ stratum.—lIt was not a little remarkable to find in both sets of observations, that the water of this Jower stratum is of Jess density than that which overlies it at 250 fathoms, though still unmistakably Mediterranean ; and it may hence be pretty certainly inferred that the denser middle stratum is drawn by cur- rent-action from some intermediate part of the Mediterranean basin at which the maximum density prevails (§ 93), and that it is flowing with a gradual upward inclination, so as at last to pass over the ridge at the op- posite extremity of the Strait. On no other hypothesis does it seem pos- sible to explain the persistence of this condition,—supposing it to be uni- form, as the close conformity of observations made after an interval of six weeks would indicate that it is. 116. Although we should have been very glad to repeat our experiments at some intermediate Section, yet, as our time did not allow of our carrying them out in more than one other locality, we considered it desirable to proceed at once to the western extremity of the Strait, where its breadth greatly increases, whilst its depth is yet more than proportionally reduced. As already stated ($ 66), the bottom is here characterized by great in- equalities; channels of from 150 to 190 fathoms’ depth existing in the immediate neighbourhood of shallows of not less than 50 fathoms (see Section EF). In accordance with the greater breadth of this part of the Strait, the easterly surface-current flows at a much lower speed than in its narrower channel; its rate being reduced from nearly 3 miles to little more than 13 mile per hour. The use of the “current-drag” at 100 fathoms from the surface, in a part of the channel of which the depth was 147 fathoms, did not indicate any reduction in this rate; but a decided reduction was shown when the ‘‘drag”’ was lowered to 150 fathoms in a part of the channel of which the depth approached 200 fathoms (§ 67). As Capt. Calver deemed it inexpedient to lower the ‘“current-drag”’ to a greater depth, since it would have been certain to foul against the rocky bottom, we were unable to ascertain by Mechanical means that the stratum of water immediately overlying that bottom has an outward movement ; but whilst the existence of such an outflow may be regarded as a necessary inference from the existence of a powerful outward undercurrent at the opposite extremity of the Strait, valid evidence of it was afforded by the VOL. XIX. s 210 Messrs. Carpenter and Jeffreys on [ Dee. 8, © fact that both the Temperature and the Density of the bottom-water brought up at two stations (Nos. 65 and 67), from 198 and 188 fathoms respectively, unmistakably indicated its derivation from the Mediterranean basin. Although its density corresponded rather with that of the 400 fathoms’ stratum than with that of the 250 fathoms’ stratum at the other end of the Strait, yet it may be very well conceived to be the water of the 250 fathoms’ stratum reduced in density during its outward flow through the Strait by intermixture with the less dense water of the in-current. 117. It nowno longer then admits of doubt that the water of the deeper part of the Mediterranean basin, which has undergone concentration by evaporation, is continually flowing outwards into the Atlantic, notwith- standing that in doing so it has to be brought nearer the surface, so as to pass over the ridge; and that the increase of density in the Mediter- ranean water, which would otherwise go on without check so long as the loss by evaporation is in excess of the fresh water returned into the basin, is thus kept within a very narrow limit. 118. The essential phenomena of the Gibraltar Current having been thus determined, we have to consider how they are to be accounted for ; that is to say, to inquire (1) what is the power which gives motion to the enormous body of water continually flowing from the Atlantic into the Mediterranean; (2) what it is which not only gives motion to the undercurrent flowing from the Mediterranean to the Atlantic, but draws. up the heavier water from the depths of the former to the comparative shallow of its limiting ridge; and (3)in what way the power is generated in each case. 119. These questions have been answered—as we believe correctly-—by Captain Maury*, on the hypothetical assumption of the existence of an undercurrent, which has now been verified. He shows that in each case Gravity is the impelling power; and that in both cases this power ori- ginates from a common source—the excess of evaporation beyond the return of fresh water by rain and rivers, which produces at the same time a reduction of the level, and an increase in the density, of the water within the Mediterranean basin; the former drawing in surface-water by gravitation from the higher level outside, whilst the latter forces out deeper water by the excess of pressure of the superincumbent column. As the vertical circulation thus occasioned has not yet, so far as we are aware, been formularized under First Principles, and as these principles have a much more extended application than Capt. Maury himself seems to have sup- posed, we shall now present them in a systematic form. 120. The following appear to be self-evident propositions :— I. That wherever there is a difference of Jevel between two bodies of Water in free communication with each other, there will be a tendency towards the equalization of their levels by a surface-fow from the height towards the lower. Physical Geography of the Sea, 1860, pp. 194-196. 1870. ] Deep-sea Researches. 211 If. That so long as the difference of level is maintained, so long will this flow continue ; and thus any agency which permanently keeps the level of one body of water below that of the other (unless it directly antagonize the downward pressure of the higher water*), will maintain a permanent surface-flow from the higher towards the lower. This constant tendency to equalization will keep the actual difference of level within very narrow limits. _ IIE. That wherever there is a want of equilibrium arising from difference of density between two columns of water in communication with each other, there will be a tendency towards the restoration of equilibrium by a flow from the lowest stratum of the denser column towards that of the lighter, in virtue of the excess of pressure to which the former is subjected. IV. That so long as the like difference of density is maintained, so long will this flow continue ; and thus any agency which permanently dis- turbs the equilibrium in the same sense, either by increasing the density of one column, or by diminishing that of the other, will keep up a perma- nent flow from the lower stratum of the denser towards that of the less dense.—This constant tendency to restoration of equilibrium will keep the actual difference of density within definite limits. V. That if there be at the same time a difference of level and an excess of density on the side of the shorter column, there will be a ten- dency to the restoration of the level by a surface-flow from the higher to the lower, and a tendency to the restoration of the equilibrium by an under- flow in the opposite direction from the heavier to the lighter column. VI. That so long as the difference of level and the difference of density are maintained, in the same sense, so long will each flow continue ; and thus a vertical circulation will be kept up by any continuous agency which alters at the same time both the level and the density of the two bodies of water,—provided that the excess of density is on the side of the lower column. | VII. That the rate of each flow, where it ig not confined within defi- nite limits, will depend simply upon the amount of disturbance, in the one case of Jevel, and in the other of density; and when this disturbance is small, it may be so slow as to be almost imperceptible, though not less real and effective. But if the communication between the two bodies of water take place through a long narrow channel, the rate of movement will increase so as to produce a decided current in each direction; since the *Thus it has been shown by Archdeacon Pratt, that in consequence of the local attraction produced by the high land of Asia, with nothing but Ocean to the southward, the sea-level at the mouth of the Indus is no less than 515 feet above that at Cape Comorin (Philosophical Transactions, 1859, p. 795). So, again, if Barometric pres- sure be Jower over any Oceanic area than on other parts of the surface, there will be an elevation of the water-level in that area, equilibrium being reached when the excess of Water-pressure becomes equal to the desiciency of Air-pressure. (See Mr. T. G. Brent in Philos. Transact. 1867, p. 5.) s 2 212 Messrs. Carpenter and Jeffreys on [Dee. 8, moving force will then act as a constantly accelerating one, until any further increase in rate is prevented by the opposing influence of friction, &c. 121. Now such an agency as that which is required by Principles VI. and VII. to maintain a double current in a narrow Strait actually exists in the cases of the Mediterranean and the Red Sea. It must be borne in mind in considering these, that whilst their basins are limited, the Ocean- basins at the other end of their respective Straits are practically unlimited ; so that the levels and densities of the latter may be regarded as constant. Now as the excess of evaporation in the Mediterranean basin at the same time lowers the level and increases the density of the water which remains, the reduction of the level gives rise to a continual surface-inflow. But, on the other hand, the restoration of the level by an inflow of salt water, the den- sity of the contents of the Mediterranean basin being already in excess, occasions a constant want of equilibrium between the columns of water at the two extremities of the Strait; and as the lighter water of the Atlantic cannot balance the heavier water of the Mediterranean, a portion of the latter is forced outwards as an undercurrent,—thus again producing a de- pression of the level, to be again restored by a surface-inflow from the At- lantic.—Thus the original moving force of both currents is the heat of the Sun. 122. The case may perhaps be made still plainer, by considering the effect of changes in its conditions. Ifthe whole amount lost by the evaporation from the surface of the Mediterranean were replaced by the fresh water of rain and rivers, there would be neither lowering of its surface nor increase of its density; and there would be neither influx nor efflux through the Strait of Gibraltar. If, again, with the present excess of evaporation, the Atlantic were to supply fresh water instead of salt, the influx through the Strait of Gibraltar would be only that required to maintain the level, and thus to supply the loss by excess of evaporation ; and as the columns at the two extremities of the Strait would remain in constant equilibrium, there would be no efflux. But as the water which flows in from the At- lantic is salt instead of fresh, and is itself rendered still more dense by con- centration in the Mediterranean, the constantly renewed excess in the weight of the Mediterranean column can only relieve itself by as continual an efflux: this efflux, by lowering the surface-level, in its turn occasions an indraught to maintain it; and thus the in-current has to replace not only the fresh water lost by excess of evaporation, but also the denser water forced out by its excess of weight. These two agencies, like the pertur- bations of the Planets, are so balanced against one another, as to maintain a constant mean. If the evaporation were to increase, more Atlantic water would flow in; but the increase of density in the Mediterranean water would cause more of it to flow out, which again would occasion a larger indraught of the less dense water of the Atlantic. And thus the excess of density would be kept down to a very moderate amount,—as is actually found to be the case in the Red Sea, notwithstanding that the enormous 1870.] Deep-sea Researches. 213 loss by evaporation from its surface is scarcely at all replaced by fresh water either from rain or rivers. 123. Now if it can be shown that a similar vertical circulation is main- tained in the opposite direction, when the conditions of the case are altogether reversed, the explanation above given may, it is submitted, be regarded as having a valid title to acceptance. Such a converse case is presented by the Baltic, an inland basin which communicates with the German Ocean by three channels—the Sound, the Great Belt, and the Little Belt—ot which the Sound is the principal. The amount of fresh water discharged into the Baltic is largely in excess of the quantity lost from its surface by evaporation ; and thus its Jevel would be continually raised, if it were not kept down by a constant surface-current, which passes outwards through the channels just mentioned. But the influx of fresh water reduces the density of the Baltic water; and as the water which the outward current is continually carrying off contains a large quantity of salt, there would be a progressive reduction of that density, so that the basin would at last come to be filled with fresh water, if it were not for a deeper inflow. Such an inflow of denser water might be predicted on Principle VI. as a Physical necessity, arising from the constant want of equilibrium between the lighter column at the Baltic end of the Sound and the heavier column at its out- let in the German Ocean; and that such an undercurrent into the Baltic has an actual existence, was proved two hundred years ago by an experiment of the same kind as that by which we have recently proved the existence of an undercurrent out of the Mediterranean. This experiment is cited by Dr. Smith (Joc. cit.) in his discussion of the Gibraltar Current, as supply- ing an analogical argument for his hypothesis of the existence of an under- current in the Strait of Gibraltar ; but he does not make any attempt to assign a Physical cause for the movement in either case*.—The condition of the Euxine is precisely parallel to that of the Baltic ; and a surface-current is well known to be constantly flowing outwards through the Bosphorus and the Dardanelles, carrying with it (as in the case of the Baltic) a large quantity of salt. Now as the enormous volume of fresh water discharged into the Euxine by the Danube, the Dnieper, and the Don would in time wash the whole of the salt out of its basin, it is obvious that its density can only be maintained at its constant amount (about two-fifths that of ordinary sea-water) by a continual inflow of denser water from the Aigean,—the existence of which inflow, therefore, may be predicted on the double ground of & priori and & posteriori necessity. GENERAL OCEANIC CIRCULATION. 124, The difference as to Level and Density between two bodies of sea- water, which produces the vertical circulation in the Strait of Gibraltar * Prof. Forchhammer fully confirms Dr. Smith’s statement; and further shows that the water which thus returns to the Baltic has the density of Sound water, the surfaces current being formed of the much lighter Baltic water. ee ee er ae | ae | 214 Messrs. Carpenter and Jeffreys on [Dec. 8 and the Baltic Sound, may be brought about otherwise than by the excess of evaporation which maintains it in the one case, or by the continual dilution with fresh water which maintains it in the other. It may be easily shown that a constant and decided Difference of Tem- perature must have exactly the same effect. Let the Mediterranean basin be supposed to be filled with water of the same density as that of the Atlantic, and up to the same level; and to be then cooled down below the freezing-point of fresh water by the withdrawal of Solar heat, whilst the surface of the Atlantic continues to be heated, as at present, by the almost tropical sunshine of the Gibraltar summer. The cooling of the Mediterranean column, reducing its bulk without any diminution of weight, would at the same time lower its level and increase its density. An in- draught of Atlantic water must take place through the Strait to restore that level ; but this indraught would augment the weight of the column, giving it an excess above that of the column at the other end of the Strait; and to restore the equilibrium a portion of its deeper water must be forced out as an undercurrent towards the Atlantic, thus again reducing the surface- level of the Mediterranean. Now so long as the warm Atlantic water which comes in to maintain that level is in its turn subjected to the same cooling, with consequent lowering of level and increase of density, so long would the vertical pressures of the two columns, which would be speedily restored to equilibrium if both basins were subjected to the same heat or the same cold, remain in a constant state of inequality; and so long, therefore, on Principles V. & VI. (§ 120), must this vertical circulation continue. 125. Now the case thus put hypothetically has a real existence. Jor the Mediterranean cooled down by the withdrawal of Solar heat, let us sub- | stitute the Polar Basin; and for the Atlantic, the Equatorial Ocean. ‘The antagonistic conditions of Temperature being constantly sustained, a con- stant interchange between Polar and Equatorial waters, through the seas of the Temperate Zone, must be the result. The reduction in the tem- perature of the Polar column must diminish its height whilst augmenting its density; and thus a flow of the upper stratum of Equatorial water must take place towards the Poles, to maintain the level thus lowered. But when the column has been thus restored to an equality of height, it will possess such an excess of weight that its downward pressure must force out a portion of its deeper water; and thus an underflow of ice-cold water will be occasioned from the Polar towards the Equatorial areas. 126. The agency of Polar Cold will be exerted, not merely in reducing the bulk of the water exposed to it, and thereby at the same time lowering its level and increasing its density, but also in imparting a downward movement to each new surface-stratum as its temperature is reduced, whereby a continual indraught’will be occasioned from the warmer surface- stratum around. For the water thus newly brought under the same cool- ing influence will descend in its turn; and thus, as the lowest stratum will 1870.] Deep-sea Researches. 215 be continually flowing off, a constant motion from above downwards will continue to take place in the entire column, so long as a fresh stratum is continually being exposed to the influence of surface-cold. 127. On the other hand, the agency of Equatorial Heat, though directly operating on only a thin film of surface-water, will gradually pump-up (so to speak) the Polar water which has reached its area by creeping along the deepest parts of the intermediate Oceanic basins. For since, as already shown, an indraught of the upper stratum surrounding the Polar basin must be continually going on, the place of the water thus removed must be sup- plied by water drawn from a still greater distance ; and thus the movement will be propagated backwards, until it affects the upper stratum of the Equatorial area, itself, which will flow off Pole-wards, bearing with it a large measure of Heat. The cold and dense Polar water, as it flows in at the bottom of the Equatorial column, will not directly take the place of that which has been draughted off from the surface; but this place will be filled by the rising of the whole superincumbent column, which, being warmer, is also lighter than the cold stratum beneath. Every new arrival from the Poles will take its place below that which precedes it, since its temperature will have been less affected by contact with the warmer water above it. In this way an ascending movement will be imparted to the whole Equatorial column, and in due course every portion of it will come under the influence of the surface-heat of the Sun. This heat will of course raise the level of the Equatorial column, without augmenting its absolute weight; and will thus add to the tendency of its surface-stratum to flow towards the lowered level of the Polar area. But as the super- heating extends but a short way down, and as the temperature of the water beneath, down to the “stratum of intermixture”’ (§ 80), is very mo- derate, whilst the water below that stratum is almost as cold as that of the Polar basin, it is evidently in the latter that the force which maintains this vertical circulation chiefly originates. 128. Here, then, we have a vera causa for a General Oceanic Circulation, which, being sustained only by the unequal distribution of Solar Heat, will be entirely independent of any peculiar distribution of Land and Water, provided always that this does not prevent the free communication between the Polar and Equatorial Oceanic areas, at their depths as well as at their surface. That this agency has been so little recognized by Physical Geographers, we can only attribute to the prevalence of the erroneous idea of the uniform deep-water temperature of 39°, of which the Temperature-observations made in our Expeditions of 1868 and 1869 have shown the fallacy. Until it is clearly apprehended that Sea- water becomes more and more dense as its temperature is reduced, and that it consequently continues to sink until it freezes, the immense motor power of Polar Cold cannot be apprehended ; but when once this hag been clearly recognized, it is seen that the application of cold at the surface is, in the case of Sea-water, precisely equivalent as a moving force 216 Messrs. Carpenter and Jeffreys on [Dec. 8, to the application of heat at the bottom, the motor power of which is universally admitted,—being practically utilized in keeping up the circula- tion through the hot-water Warming-Apparatus now in general use *. The movement thus maintained would not, on the hypothesis, be a rapid one, but a gradual creeping flow ; since the absence of limit would prevent the power which sustains it from acting as an accelerating force, as it would do if the Equatorial and Polar areas were connected only by a narrow channel, like the Atlantic Ocean and the Mediterranean Sea (§ 120, Princ. VITI.). 129. That the Vertical Circulation here advocated on @ priori grounds actually takes place in any mass of Salt water of which one part is exposed to surface-Cold and another to surface-Heat, is capable of ready experi- mental proof :——Let a long narrow trough with glass sides be filled with salt water; and let heat be applied at one end (the Equatorial) by means of a thick bar of metal laid along the surface, with a prolongation carried over the end of the trough into the flame of a spirit-lamp ; whilst cold is applied at the other (the Polar) by means of a freezing-mixture contained in a metallic box made to lie upon the surface, or (more simply) by means of a piece of ice wedged in between the sides of the trough. A circulation will immediately commence in the direction indicated by the theory; as may be readily shown by introducing some 6/ue colouring liquid at the Polar surface, and some red liquid at the Equatorial surface. The blue liquid, as it is cooled, at once descends to the bottom, then travels slowly along it until it reaches the Equatorial end of the trough, then gradually rises towards the heated bar, and thence creeps along the surface back to the Polar end; the red liquid first creeps along the surface towards the Polar end, and then travels through exactly the same course as the blue had previously done +. 130. That such a Vertical Circulation really takes place in Oceanic Water, and that its influence in moderating the excessive Cold of the Polar Areas and the excessive Heat of the Equatorial region is far more important than that of any surface-currents, seems to us a legitimate deduction from the facts stated in the Report of the ‘ Porcupine’ Expedition for 1869. For, on the one hand, it was shown ($§ 116-118) that there is a general diffusion of an almost glacial temperature on the bottom of the deep Ocean-basins, * The only scientific writer who has even approached what appears to us the truth on this point is Captain Maury, who has put forward the doctrine of a general inter- change of water between the Equator and the Poles, resulting from a difference of Specific Gravity caused inter alia by difference of Temperature. But, as Mr. Croll . remarks, ‘although Capt. Maury has expounded his views on the cause of Ocean- currents at great length in the various editions of his work, yet it is somewhat difficult to discover what they really are. This arises from the generally confused and sometimes contradictory nature of his hydrodynamical conceptions.’ See Mr. Croll’s Paper “ On the Physical Cause of Ocean-currents ” in the Philosophical Magazine for October, 1870. t This experiment has been exhibited, by the kindness of Prof, Odling, at the Royal Institution and at the Royal Geographical Society. 1870.] Deep-sea Researches. 917 which, at depths exceeding 1000 fathoms, are occupied by Polar water, more or, less diluted by admixture according to the Jength of the course it has had to travel ; whilst between this stratum and that other stratum of warmer water which (on the hypothesis) is slowly moving Pole-wards, there is a ‘‘stratum of intermixture,” in which there is such a rapid change of Tem- perature as might be expected from the relation of the upper and lower masses of water. This “stratum of intermixture’’ showed itself in a most marked manner in the Atlantic Temperature-observations of the present Expedition (§ 80); the descent of the Thermometer, which had been very slow with increase of depth between 100 and 800 fathoms, becoming suddenly augmented in rate; so that between 800 and 1000 fathoms it fell nine degrees, namely from 49°°3 to 40°°3. 131. On the other hand, it was shown in the previous Report (§§ 119- 121) that there is evidence of the slow Pole-ward movement of a great upper stratum of Oceanic Water, carrying with it a warm temperature ; which movement cannot be attributed to any such local influences as those which produce the Gulf-stream or any other currents put in motion by surface- action. Of such a movement, it was contended, we have a marked example in that north-easterly flow which conveys the warmth of Southern latitudes to the West of Ireland and Scotland, the Orkney, Shetland, and Faroe islands, Iceland, Spitzbergen, and the Polar basin generally. This flow, of whose existence conclusive evidence is derived from observations of the Temperature of these regions, is commonly regarded as a prolongation of the Gulf-stream ; and this view is maintained not only by Dr. Petermann*, who has recently collected and digested these observations with the greatest care, but also by Prof. Wyville Thomson ft, as well as by Mr. Croll {. Having elsewhere fully stated our objections to this doctrine, and discussed the validity of the arguments adduced in support of it $, we shall here only record the conclusions which a careful examination of the present state of our knowledge of the subject has led us to form :— I. That there is no evidence, either from the Surface-temperature of the Sea or from the temperature of sea-bord Stations along the western coast of Southern Europe, that the Climate of that region is ameliorated by a flow of Ocean-water having a temperature higher than that of the Latitude,—the surface-temperature of the Mediterranean Sea, which is virtually excluded from all Oceanic Circulation, being higher than that of the eastern margin of the Atlantic in corresponding latitudes, and the Climate of sea-bord Stations on the Mediterranean being warmer than that of Stations corresponding to them in Latitude on the Atlantic Coast ; and this not merely in summer, but also in winter. This Oceanic region may therefore be designated the neutral area. * Geographische Mittheilungen, 1870, p. 201. + Lecture “On Deep-sea Climates,” in Nature, July 28, 1870. { Memoir “ On the Physical Cause of Ocean-Currents,” in Phil. Mag. Oct. 1870. § Proceedings of the Royal Geographical Society, for Jan. 9, 1871. 218 Messrs. Carpenter and Jeffreys on [Dee. 8, II, That the evidence of Climatic amelioration increases in propor- tion as we pass Northwards from the neutral area, becoming very decided at the Orkney, Shetland, and Faroe islands ; but that, as was shown by the ‘ Porcupine’ Temperature-soundings of 1869, the flow of warm water which produces this amelioration extends to a depth of at least 700 fathoms. IIT. That this deep stratum of Warm water can be shown, by the corre- spondence in the rate of its Diminution of Temperature with depth, to be de- rived from the neutral area to the south-west ; where, as is shown by the ‘ Porcupine’ temperature-soundings of 1870, it is separated by a distinct ‘stratum of intermixture’’ from the deeper stratum that carries Polar waters towards the Equator. IV. That the slow north-easterly movement of such a mass of water cannot, on any known Hydrodynamical principles, be attributed to pro- pulsive power derived from the Gulf-stream; the last distinctly traced edge of which is reduced to a stratum certainly not exceeding 50 fathoms in depth, and not improbably less. + VY. That, on the other hand, this slow Pole-ward movement of the upper warm layer of the North Atlantic, down to the “stratum of intermixture,” is exactly what might be expected to take place as the complement of the flow of glacial water from the Polar to the Equatorial area, the two movements constituting a General vertical Oceanic Circulation. VI. That there is a strong probability that the quantity of Water dis- charged by the Gulf-stream has been greatly over-estimated, in consequence of the rate of the surface-current having been assumed as the rate of movement through the whole sectional area, which is contrary to all analogy ; whilst there is also a strong probability that there is a reverse undercurrent of cold water through the Narrows, derived from the Polar current that is distinetly traceable nearly to its mouth. The upper stratum of this southerly current comes to the surface between the Gulf-stream — and the coast of the United States; whilst its deeper and colder stratum underlies the Gulf-stream itself *. VII. That there is a strong probability that the quantity of Heat carried off by the water of the Gulf-stream has been greatly over-estimated ; the Temperature-soundings taken during the Cruise of the ‘ Porcupine’ in the Mediterranean having shown that the very high temperature of the surface extends but a little way down, whilst the Temperature-observa- tions in the Atlantic show that the descent into a cold stratum beneath * That there is a slow southerly movement of Arctic water beneath the Gulf-stream is indicated by the fact that icebergs have been seen moving southwards in direct op- position to its surface-flow, their deeply immersed portion presenting a larger surface to the lower stratum than their upper part does to the more superficial layer,—as in the case of our “current-drag.” And similar evidence is afforded by the southward drift of the buoy which was attached to the Atlantic Cable of 1865, but which broke away from it, apparently carrying with it a great length of the wire rope by which it had been attached. .1870.] .» Deep-sea Researches. 219 may be very rapid. Uence the average of 65° assumed by Mr. Croll on the basis of observations made at considerable intervals of depth is alto- gether unreliable. VIII. That the most recent and trustworthy observations indicate that the edge of the Gulf-stream to the north-east of the Banks of Newfoundland, is so thinned out and broken up by interdigitation with Polar currents, that its existence as a continuous current beyond that region cannot be proved by observations, either of a or Move- ment. IX. That the Gulf-stream and other local currents put in motion by the Trade-winds or other influences acting on the surface only, will have as their complement in a horizontal circulation return surface- currents; and that the horizontal circulation of which the Atlantic Equatorial Current and the Gulf-stream constitute the first part, is completed—so far as the Northern Hemisphere is concerned—partly by the direct return of one large section of the Gulf-stream into the Equatorial Current, and, as to the other section, by the superficial Polar currents, which make their way southwards, the principal of them even reaching the commence- ment of the Gulf-stream. 132. In conclusion it may be added that the doctrine of a General Vertical Oceanic Circulation is in remarkable accordance with the fact now placed beyond doubt by the concurrent evidence of a great number of observations, that whilst the Density of Oceanic water, which is lowest in the Polar area, progressively increases as we approach the Tropics, it again shows a decided reduction in the Intertropical area. It has been thought that an explanation of this fact is to be found in the large amount of rain- fall, and of inflow of fresh water from great rivers, in the Intertropical region; but it is to be remembered that the surface-evaporation also is there the most excessive ; so that some more satisfactory account of the fact seems requisite. Such an explanation is afforded by the doctrine here advocated, the Polar water which flows towards the Equator along the bottom of the ocean-basins being there (so to speak ) pumped up and brought to the surface *. And it is nota little confirmatory of the views advanced in this Report, that in a recent elaborate discussion of the facts relating to the Comparative Density of Oceanic Water on different parts of the Earth’s surface, the doctrine of a General: Vertical Circulation is advocated as affording the only feasible rationale of them +. * That water of a ower should thus underlie water of a higher degree of Salinity, in travelling from the Pole to the Equator, is not difficult toaccount for, when the rela- tive Temperatures of the two strata are borne in mind. tT “ Densité Salure et Courants de Océan Atlantique,” par Lieut. B. Savy, Annales Hydrographiques, 1868, p. 620. 220 “Messrs. Carpenter and Jeffreys on = — [Dee 8, First Cruise oF THE ‘ Porcupine’ (Chart I.). : Depth Surface Bottom Station North West . No. Latitude. | Longitude. Fathoms. Temp ans Ppigberaiaite, me) AB” Be 1 015 567 fo ae. 2. 48 37 10.9 305 61°5 48°5 3. 48 31 10 3 690 sakes ae 4. 48 32 9 59 ree 61:5 45°3 5. 48 29 9 45 100 62°3 51:5 6. 48 26 9 44 308 62-0 50:3 a 48 18 ars le 93 61-0 51:3 8. 48 138 oo Th 257 60:7 50:0 9. 48 6 9218 539 64:0 - 48:0 10. 42 44 9 23 81 60°5 53'D Hs 42 32 9 24 332 60°5 51°5 12. 42 20 Dy 128 61°5 52°3 13. 40 16 9 37 220 64:5 52:0 14, 40 6 9 44 469 65°3 d1°5 15. 49 2 9 49 722 67:5 49-7 16. 39 55 9 56 994 69°5 40:3 B/G 39 42 9 43 1095 68-0 39°7 NGA 90) 9 9 39 740 67°5 49°3 18. 39 29 9 44 1065 65:0 39°7 19, 39 27 9, 2309 248 64:7 BLT 21. 38 19 9 30 620 67:3 50°5 22, 38 15 9 33 718 66°3 52:0 23. a4. 20 9 30 802 66°5 49:3 24. 37. «19 9 13 292 67:5 52:7 20. BP «Al voi 374 69-7 53'5 26. 36 44 8.258 364 (Ase 52°7 27. 36 37 7 383 322 73°0 51:3 28, 36 29 f oh 304 71:5 53°3 29. 36 20 6 47 227 73°3 550 30. 36 15 6 62 386 73°0 52-7 31. 35 56 T° 477 71:3 50°5 32. 35 41 FOS 651 71:5 50:0 33. 35 «3d 6 54 bo4 72:0 49-7 34. 35 44 6 53 414 ray 50:0 30. 35 39 6 38 335 73°5 51°5 36. 35 39 6 26 128 75:0 55°0 37. 35 650 6 0 190 72:0 53:7 38. 35 «58 5 26 503 117 54:0 aa ; ; ? Chart I. GULF or LYON Sie _ oNAPLES oO p o to” | payor NAFY™ @ B fe) 5° ; 15° ee Engraved by Malby & Sons. D? Grpenter CRUISE OF THE PORCU PINK 1870. MADRIDo | N 4 sa s = =e = c= A iN c le AS ee GULF or LYON Barcelona St:fof Bonafacio Ne altar 38 555 ie Valenciao Tong. 5° West from Greenwich + ———— Sf Long. East from Greenwich 1359 == a. ) ° Jb aaeeeereeeeee| Engraved by Milby & Sons. . ‘ gary hae * OMA Le oan BOA greatiapiS : cara i Nyt hmany staat or ia apres i pe ia Foes re enor BR AM ae Ded vepignes gg 2 r t ait Lae ‘ee D* Carpenter ‘S SCALE of FATHOMS DH & | / M SS Ne Gee = 103 | a7, Pk 2 ee ee re i TOOTS es oe if 1 138 j | 152 aoe 180 66) 167 { 225 | 142 106 A Gea a ee Sea ae ‘tae ESE AR. Gil er { a 45 139 1 i IT 1 1 155! 1 : / 133 / 7 132 167 ih @ 194. \ 166 31." 50’. 37 se 35 t 00 | © Spartey aj NUN NTA | nen : Va Nain ESESSISS SSE SURGES en Cet ES TES —r Long -West 6|° from Greenwich bon Engr aved. by Malby & Sons 1870.) Deep-sea Researches. Aan 221 Srconp CrviseE or THE ‘ Porcupine’ (Charts I. and IT.). Station North Ris Depth Surface Bottom Be crude | eMeeee Ee | Pepeecinm (Tempter Sau 35) 59 |. os QW. 517 66-0* 55-5 Hoe 36°. 01. | 4. 40 W, 586 74-5 55-0 41. | 35 57°) 4 12. 730 44-5 55-0 Hoe 385 «45 = 8.57 W. 790 74-0 54-0 43. | 35 24 | 3 54W. 162 re 55-0 ee 85 4914 3 (1 W. 455 70-0 55-0 45, | 35 36 | 2 29W. 207 72-7 54-7 4G.) 35 39 | 1 BOW. 493 73-5 55-5 ee 37 95 |) 1 10 W. 845 69-5 54-7 A a7 - | oO B1W.|. 1398 735 54-7 49..| 36 29 | 0 31W.| 1412 rats 54-7 50. : 51 BOa,|{ Algerine; 152 r4.Ae 50p. || Coast 510 mies 55 .|.1,.103%..(. 1415 75-0 54-7 52. } Algerine 660 } 76-9% 52a. Coast nea 590 Bf) 36 58..| 52555. 112 77-0 55D 54.) 37 41 | 63.27E. | 1508 76-0 55-0 55. | 37 30 | 6S51E.| 1456 76-5 55-0 ee owe 3-11 - 365. 390 78-0 56-5 ee 36° G6 (18 10. 294 76-83% BS'|*36 43° 113 368. 266 5-5 56-5 59. | 36 32 |14 198. 445 76-5 56-5 60. | 36 31 M5 46k. | 1743 74-0 56-0 61, | 38 26 |15 328. 392 79-5 55:7 62..| 38 38 |15 Q1E. 730 72-5 55-3 63. 1) 181 68-0 54-7 64. 460 65-6 BAT 65. | RecA aE 198 63-0 54-5 66. cuca 147 69-0 Therm. lost 188 73-0 55:3 * These temperatures are the averages of the day. 45° 40 LONGITUDINAL SECTION ON THE LINE A.B. sa 3390 ue | ia fit sea Pistia i b N.36°Lat. -~— nae i ane a ay lines a ’ 1870.) | Deep-sea Researches. ue 221° ? Seconp CrvissE or THE ‘ Porcupine’ (Charts I. and II.). “Station North Depth Surface Bottom | RRs Ba ime a co 99. | 35. 59-| 5. 27W. 517 66-0* 55-5 40,| 36 0 | 4. 40W. 586 74-5 55-0 A 35 57 e412. 730 4-5 55-0 ae) 35 «45 =| (857 W. 790 74-0 54-0 a3. | 35 24°19 54, 162 74-7 55-0 Pees 498" 8 LW. 455 70-0 55-0 45,| 35 36 | 2 29W. 207 79.4 54-7 46.1 35 39 | 1 56W. 493 13-5 55-5 eee 37 95 | 1 «10W. 845 69-5 54-7 a 37°97. | 0 31 w.|. 1398 73-5 54-7 aoe 36.99. |. 0 31 W.| W412 15 54-7 50. 51 50a,|{ Algerie) 152 eae 50b, || Coast 510 pea: 55 .| 1. 10Ei|:. 1415 75-0 54-7 52. } Algerine 660 } 76-9% 52a. Coast beats 590 53. | 36 53 | 5E55E. 112 77-0 555 a 87. 41. «| 63.27 B. | 1508 76-0 55-0 Se | 37 30.| 6251E. | 1456 76-5 55-0 ee ore od 96 5. 390 78-0 56-5 nee 36 6 «18. 10 F. 294 76-3% 58.) 36 43 113 36E. 266 5-5 56:5 59. | 36 32 |14 128. 445 76-5 56-5 60. | 36 31 115 46K. | 1743 74-0 56-0 61. | 38 26 |15 32E. 392 79-5 55-7 62..| 38 38 115 QE. 730 72-5 553 63. |) 181 68-0 54-7 64. 460 65-6 54-7 65. oer Me 198 63-0 54-5 66. 147 69:0 Therm. lost | 188 73-0 553 * These temperatures are the averages of the day. 203 Mr. E. Hull on the Coalfiélds beneath (Dec. 15, December 15, 1870. General Sir EDWARD SABINE, K.C.B., President, in the ee "The Duke of Sutherland was admitted into the Society. The reading of the Report on Deep-sea Researches carried on during the months of July, August, and September 1870, in H.M. Surveying Ship ‘ Porcupine,’ by Dr. Carpenter, F.R.S., and. Mr, J. Gre Jeffreys, F.R.S., was resumed and concluded. December 22, 1870. General Sir EDWARD SABINE, KG: - President, in the Chair. ‘The following communications were read :— I. “ On the Extension of the Coal-fields beneath tlle Newer Forma- tions of England; and the Succession of Physical Changes whee the Coal-measures have been reduced to their present dimensions.” By Epwarp Hutt, M.A., F.R.S., E.G. S., Director of the Geolo- gical Survey of Ireland. ‘Received Noverber 30, 1870. : (Abstract.) In this paper the author, embodying with his own the observations of previous writers on the physical geology of Great Britain, especially those of Murchison, Godwin-Austen, Ramsay, Phillips, and the late Professor Jukes, showed that the Coal-measures were originally distributed over large tracts of England, to the north and to the south of a central ridge or barrier of Old Silurian and Cambrian rocks, which stretched across the country from North Wales and Shropshire into the Eastern Counties, skirting the southern margin of the South Staffordshire Coal-field. This barrier, or ridge, was a land-surface till the close of the Carboniferous period. To the north of the central barrier, the highlands of Wales, the moun- tains of the Lake-district, and probably small tracts of the southern uplands of Scotland formed land-surfaces skirting portions of the Carboniferous area, while the Carboniferous tract to the south of the central barrier was probably bounded by a land-surface trending along the southern coast of England. The distribution of the Coal-measures at the close of the Car- boniferous period was illustrated by a Map, No. 1. It was then shown that the whole Carboniferous area was subjected to disturbances through the agency of lateral forces, whereby the strata were thrown into folds along axes ranging (approximately) in east and west directions ; and as denudation accompanied and followed these disturbances, and acted chiefly over the arches (or anticlinals), large tracts were divested of Upper Carboniferous strata, and thus the first phase in the marking out of the limits of our present coal-fields was brought about. The effects of these movements and denudations were illustrated by Map No. 2. The disturbances which ensued after the deposition of the Permian 1870.] =. ~—sthe Newer Formations of England. 223 strata, and which produced the discordances of stratification between the newer Palzeozoic and Mesozoic formations, were shown to have acted along lines ranging approximately north and south, parallel to the axis of the Pennine Chain, and consequently in a direction transverse to those of the previous period. These disturbances were also accompanied by the denu- dation of strata from off the anticlinal arches, and the consequent dis- severance of the Coal-measure tracts over certain definite areas. ‘The re- sults of these movements (the second phase in defining the bounds of the coal-fields) were illustrated by Map No. 3. From a consideration of the foregoing observations, the author came to the conclusion that the tendency of the British coal-fields to arrange them- selves into the form of ‘basins’? (sometimes partially concealed by newer strata), a tendency strongly insisted on by Prof. Ramsay, F.R.S., was due to the intersection of the two systems of flexures above described, one anterior to the Permian period, the other anterior to the Triassic period, and that the actual disseverance of the coal-fields into basins was due to denudation acting with greatest effect along the anticlinal arches of these flexures. The inference that the Yorkshire and Durham coal-fields are really basins rising to the eastward under the Mesozoic strata was drawn, an in- ference supported by the easterly rise of the Coal-measures along the sea-coast from the Coquet to the Tyne. Guided by these principles, the author maintained that we are now i a position to determine with great accuracy the actual limits of the Coal- measures under the Mesozoic formations over the area to the north of the central barrier ridge (as indicated on Map No. 3); and that to the south of the ridge the application of the same principles would assist towards the solution of the question, though in a less degree, owing to the fewer opportunities for observation of the Paleozoic formations. The author, however, concurred in the views advanced by Sir R. I. Murchison*, that in consequence of the great amount of denudation which the Carboniferous rocks had undergone over the area of the south of England previous to the deposition of the Mesozoic formations, little coal was to be expected to remain under the Cretaceous rocks. II. “On the Constitution of the Solid Crust of the Earth.’ By the Ven. Joun Henry Prart, Archdeacon of Caleutta, M.A., F.R.S. Received September 19, 1870. (Abstract.) In this paper the author applies the data furnished by the pendulum-ob- servations recently made in India to test the truth of the following hypo- * In his Address at the Meeting of the British Association at Nottingham, 1866. On the other hand, the views of Mr. R. Godwin-Austen, F.R.S., which tend rather in an opposite direction, should be well weighed by all who are interested in this question, (Quart. Journ. Geol. Soe, vol. xii.) 224: On the Constitution of the Crust of the Earth. [Dec.22, thesis regarding the Constitution of the Earth’s Crust, which he pro- pounded in 1864, viz.: that the variety we see in the elevation and depression of the earth’s surface in mountains and plains and ocean-beds has arisen from the mass having contracted unequally in becoming solid from a fluid state ; and that below the sea-level, under mountains and plains, there is a deficiency of matter approximately equal in amount to the mass above the sea-level ; and that below ocean-beds there is an ‘excess of matter ap- proximately equal to the deficiency in the ocean when compared with rock ; so that the amount of matter in any vertical column drawn from the sur- face to a level surface below the crust is now, and ever has been, approxi- mately the same in every part of the earth. In order to make this hypothesis the subject of calculation, the author takes the case of the attenuation of matter in the crust below mountains and plains, and the excess of matter below ocean-beds, to be uniform to a depth m times the height above the sea-level or the depth of the ocean, as the case may be. - The results are shown in the following Table, in which the numbers are the last figures in the ratio of the differences of gravity to gravity itself, carried to seven places of decimals. The decimal point and ciphers are omitted for convenience. Differences of gravity. Residual errors after correction by the Stations. Relative method of effects of local attraction deduced from This hypothesis. pendulum- | Dr, Young. observations. m=50. m=109. Indian are stations. PODER en cs ses ce enteral tty seeeee a: lh focmmeneieeeitdlin acaeetce aaa tan Bangalore ......000... +384 — 562 — 78 —557 Damarvida <.. ssc. s- — 323 — 926 —455 — 584 MaMa oss oa's xs oe +341 — 208 +338 +315 ataM a, Sac cken ae eee — 707 —957 + 69 +320 Coast stations. PUTIN A rece degediwel assent” Gb. WSAaee | Ma eee en Plloppy tits sive. dea noes +302 +514 +331 +360 Mangalore ............ —166 —154 —122 — 79 MATHS, "2. .pacses rence: —197 —192 —138 — 78 Woeanada ‘00005 eekt. +142 +153 +216 +291 Ocean station. Minicoy Island ...... +894 +906 + 31 +102 The author points out from this Table that Dr. Young’s, or the usual method of correction for local attraction, so far from improving matters, introduces very large residual errors of the arc and ocean stations; and, at places on the are of meridian, all lying on the same side with reference to Punne. He observes that neither the usual method nor his own much 1870. ] On Actinometrical Observations in India. 225 affects the coast stations; and attributes this to the want of more complete knowledge of the contour of the surface, both above and below the sea- level, in these parts. But his own method, in the case m=50, remarkably reduces the effects of local attraction at stations on the are of meridian and out at sea (in Minicoy, an island 250 miles west of Cape Comorin or Punneze); for the sensible negative quantity at Damargida and positive quan- tity at Kalianpur indicate a deficiency of matter below the first and an excess below the second, which exactly tally with the results independently brought out by relative deflections of the plumb-line as obtained by the sur- vey: and the two large and most important effects, negative at Kaliana and positive at Minicoy, may be said to be almost annihilated by this method of correction. This last case of an excess of gravity out at sea (where the surrounding ocean has a deficiency of matter) being explained by his me- thod, he regards as a very strong argument in its favour. And he finishes by saying that if his method is thus far successful in the particular sup- position of the distribution below, whether in excess or defect, being wnr- form, which is most likely not strictly the case, there is every reason for concluding that pendulum-observations give support to the hypothesis regarding the Constitution of the Earth’s Crust, when viewed on a large seale, admitting of local peculiarities, like the deficiency of matter near Damargida and the excess near Kalianpur, and the similar deficiency near Moscow. III. “ Actinometrical Observations made at Dehra and Mussoorie in India, October and November 1869, in a Letter to the Pre- sident.” By Lieut. J. H. N. Hennessey. Communicated by the President. Received September 7, 1870. Mussoorie, July 22, 1870. My pear Srr,—In continuation of my last communication, dated April 25, 1870, I have now the pleasure to forward the actinometrical observa- tions taken, during portions of October and November 1869, with the in- straments of the Royal Society, and in compliance with the suggestions which the Committee of the Society made for my benefit. (2) The two actinometers are of the kind invented by the Rev. G. C. Hodgkinson, and described by him in the Proceedings of the Royal Society, No. 89, vol. xv. Further description or allusion is therefore un- necessary, unless I add that the instrument is easily and accurately worked after but moderate practice, and that it is little liable to accident if rolled up in a padded sheet and packed within its own metal tube. It, however, imposes sensible drawbacks, from the delays incurred in throwing off a suitable amount of fluid into the chamber ; and as this adjustment becomes deranged by any considerable alteration in the radiation, it is impossible to VOL. XIX. | T 2260 Lieut. Hennessey on Actinometrical [Dec. 22, continue a series of observations for any lengthened period (as, say, two hours) without introducing breaks of several minutes in its continuity. (3) The two instruments used have been lettered by the observers A and B. The glasses, too, have been suitably marked as suggested by Sir John Herschel in the ‘Admiralty Manual of Scientific Enquiry.’ Actino- meter B was used at Dehra by Mr. W. H. Cole, M.A., whose observations in sun and shade number 405 in all. The observations at Mussoorie were made by myself with actinometer A; they are 315 in number. And as respects the chronometers, barometers, and thermometers employed, 1 need hardly add that these instruments were of a superior order and well verified, or that they are in ordinary use at the head-quarters of Colonel Walker, R.E., Superintendent of the Great Trigonometrical Survey of India. (4) And with every facility for reading the last-named instruments, I regret having omitted to arrange for a more frequent reading of the baro- meter, and that the wet- and dry-bulb thermometers were not recorded. It, however, so happened that during the days of observation in October and November last the sky was beautifully clear, with the trifling excep- tions noted in the records of observations ; and there is no reason to sup- pose that any sudden changes occurred in the hygrometric conditions of the atmosphere. In future, however, when the actinometers can again be worked, more numerous readings of the barometer and thermometers will be duly recorded. (5) The stations of observation were Mussoorie and Dehra. The direct distance; between them is about nine miles. The former stands on one of the southernmost ranges of the Himalayas; the latter is in the valley Dehra, or Dehra Dhoon. The hypsometrical elements for these stations, given in the result-abstract and elsewhere, are taken from the records of the Trigo- nometrical Survey of India. It appears from these values that Mussoorie station is above that at Dehra about 4700 feet. (6) The procedure agreed on between Mr. Cole and myself was to ob- serve daily a simultaneous series at 11" 40" a.m. (mean of all the observed times), another series at noon, and a third at 0> 20" p.m., the reckoning being in apparent time. The slight deviations from these times which appear in the result-abstract are due to little accidental causes almost in- separable from simultaneous work. After four days of these series, each ob- server was to determine the amount of heat stopped by the glass of his instru- ment employed. In these experiments I was too busy otherwise to recipro- cate Mr. Cole’s observations of November 1. On the 3rd of November, however, we both observed the intended succession of groups (nearly); so that several of these are made to discharge a double duty, and are intro- duced in the after-discussion of relative radiation. On November 4 we > each obtained a complete hourly series about the hours of 8 a.m. to 4 p.m. These results terminated for the time the reciprocal series of ob- servations Mussoorie-Dehra. Subsequently, in April 1870, when we were 1870.] Observations in India. 227 both at Dehra, we carefully compared the two actinometers A and B together. This was the only occasion during all our observations when light clouds occasionally passed over the sun. But as the two instruments were set up within 3 or 4 feet of one another, and as we both used the same chronometer and read our scales at the same instant of time, there appears no reason why the results should not be accurate, relatively speaking. (7) The constants thus determined are as follows :— Obtained from six groups glass off and five groups glass on, comprisingsixty- five observations in all. ( Obtained from two sets of | observations, each con- | sisting of four groups ” B Factor No.2, ,, ” =1-04 4 glass offand three glass on, and comprising ninety- six observations in all. Factor No. 3, obtained from comparisons between A and B comprising 112 simultaneous observations, of which the following is a result-abstract reduced to 32° Fahr. and expressed in tenths of A’s scale (both glasses on): — Factor No. 1, to convert readings | Actinometer A with glass on into readings =1:09 glass off. A. B. A. B. oes Observed Observed B—A. abpatent Observed] O bserved) B—A. y by y. by J.H.N.H./W. H.C. W. H.C. | J.H.N.H. hm s hm s 11 26 o| 819 832 130 it 445. oF 783 806 18 oO 8 oO} 3828 $30 2 OrZ5 Ol con 817 13 o 51 o| 758 781 23 St 4Olae794 816 22 ZAI, 0} 786 794 3 PARC ay (6) 681 15 Mean...| 798 809 12 ||Mean...| 763 780 17 mean A __ nee aa B mean B 794°5 We may also deduce (W. H.C. at B) —(J. H.N. H. at A)=11. (J. H. N. H. at B)—(W. H. C. at A)=17. The accordance of these two average differences shows that no sensible “ personal equation”’ appeared to exist between the observers. (8) The observations simultaneous at Mussoorie and Dehra were, in the first instance, separated into groups, and combined group by group for a result. Subsequently groups were formed so as to include all the observations taken, subject to the following conditions :— Seven (or fewer) sun-observations, with the intermediate observation i in shade, were combined to produce one result. Eight sun-observations, with the intermediate observations in shade, gave r?2 228 Lieut. Hennessey on Actinometrical [Dec. 22, groups of 5 and 4 sun-observations respectively (those in shade are here understood), the fifth sun being common to both groups. Nine ditto, ditto, gave 5 and 5. Ten ditto, ditto, gave 6 and 5. Eleven ditto, ditto, gave 5, 4, and 4; and so on. (9) The mean results by each group were next all corrected for excess of temperature above 32° Fahr., the Table of expansion for alcohol by Kopp, given in Gmelin’s ‘Chemistry,’ being employed for this purpose. After this step the results by A were entered in the result-abstract Table and the corresponding values, in terms of A glass off, found by means of factor No. 1. The results by B were further corrected in the record of observations by means of factor No. 3. Being now in terms of A glass on, they were introduced into the result-abstract Table, and there reduced to A glass off, by means of factor No. 1. (10) Thus the result-abstract Table contains the values obtained by each actinometer expressed in terms of A glass on as well as glass off. The latter values are those made use of in projecting the actinometric curves, and in the discussion of the observations. The former values will be useful should the Royal Society see fit to send me a third actinometer whose constant for reduction to the Kew standard has been duly ascer- tained. At present the required relation is wanting ; for though Professor Stokes was so exceedingly kind as to visit Kew with the object of getting the actinometers A and B verified, the necessary observations could not be made from want of time. (11) Turning, now, to the diagram of actinometric curves and to the re- sult-abstract Table, it is readily seen that the solar radiation decreases from some time about apparent noon both towards sunrise and sunset. This hour-angle change is least perceptible for some +1 hour (or less) from noon—a condition which indicates that observations for relative or abso- lute intensity are most valuable when made during this interval. Indeed even desultory observations might acquire importance by being restricted to these hours, the absence of cloud, mist, haze, or other abnormal inter- position being always supposed. (12) But besides the hour-angle change, the intensity is liable to rises and falls brought about in only a few minutes of time. Any observer who has used the instrument could venture to affirm that these fluctuations are not due to fallibility of observation. Whether their magnitude varies with that of the intensity or otherwise may be a matter of interest to ascertain ; and to this end series of observations, continued for as long a period as the construction of the instruments will permit, appear desirable. (13) Again, there is a change of intensity from day to day, apparently not due to alteration in the sun’s declination, so that the average daily curve (about noon) is higher or lower without any visible reason. It is interesting to notice that this daily change was common to Mussoorie and 1870.]- | Observations in India. 229 Dehra. The two stations, it will be remembered, are about nine miles apart, and situated nearly on a common meridian. (14) Collecting the results of observations, we obtain the following from simultaneous groups only :-— TaBLe I. | M* | D*® |M—D. M. D. |M—D. hm s beans 27th. | 11 49 30 | 1007 | 876 | 131 3rd. | 11 14 30 © 9 30} 968 | 904 64 Outs: © Tee lp ae te © 29 30 | 941 | 888 53 II 46 o Ba St oe = Gas to fo se oe ane Mean (.2:<. 972 | 889 $3 © 0 O|} 1006} 908 98 OUTS). O:)|% LOns|cQz9 36 28th.| 11 40 0 | 955] 887 68 © 30 O]| 1005} 924 31 © 0 of 969 | 883 86 045 ©] 1020] 937 83 4th.| 8 3 30 847| 718 | 129 | | 2gth. 1 O: 3 30 aE bp 4-0 943) 821) izze4| me 4, 30 G24 1 O95 BS 1G 8), 10 996| 876 | 120 | ° 6 ° 8 ° oS Pe | OE he % a 1000] gog gI Mean ...... 975 | 901 74 o 6 30 986) 913 73 Be OF-\0 984} 892 92 goth.| 11 40 0 | 980] g12 68 21D 30 6 0 1 30} 977| 903 | 74 eo elt ee a o 18 30} 983] 919 | 64 | 3 9 30 911) 758 | 153 ae aimee) oS 775} 549 | 235 Mean ...... 980 | git 69 Mean from) 115 10™ to| 999} 905 85 eonees Collecting these average daily results for +1 hour (about) from noon, we have :— TABLE II. M. DES iM] Dp: 1869. Oct. 27. | 972 | 889 83 235) (ObR | "S85 66 295 | > 9255 | 199% 74 g05, |. 980) |" (O98 69 Nov. 3. | 1oro | 923 87 4-| 999} 905 |. 35 Mean. ...-- 980 | 902 77 | and = =1'086. (15) In Tables I. and II. I have availed myself of none but actually si- multaneous observations. We may, however, include every result at either station, provided the curve at the other station exists for the required time. * M stands for Mussoorie, D for Dehra. 230 Lieut. Hennessey on Actinometrica: [Dec. 22, Thus at Dehra, October 28, we have the result 880 observed. The corre- sponding result at Mussoorie (7. e. at 11" 15™) is found from the diagram to be 945. Proceeding in this manner, and taking averages of all results within 5 minutes of one another to make one result, we find :— Taste III. M. | D. |M—D. M. | D. M—D. hms hy tas 27th. | 11 49 30 | 1007 | 876 | 131 grd.| 11 15 45 | 1002 | 927 75 © 9 53 | 969 | 904 65 II 30 © | 1008 | 918 go © 29 30} 941 | 888 53 II 36 30 | ror0 | 916 94 —_—— |—_—_— |—_—_— II 45 30 | 1013 | 912 | 10K Mean ice. 972 | 889 83 © © 0] 1006 | 908 98 0. ¥5 ..0.| 10nd 4 B28 36 2Sthe |, 12215 0% O45 1780 65 © 30 O| 1005 | 924 81 Ii 20-0"! 943 | 1S8x 62 945 ©} 1020 | 5937 83 | © 33 39 | 937 | 885 | 52 4th.| 8 3 30 | 847 | 718 | 129 | Mean ...... 946 | 883 63 9 11 23 | 943 |) 8230) 20 10 68 45 996 | 870 | 120 | Z2Oth. Ou 304-5 984 | 897 87 II 9 45 | 1001 | 905 96 © 21/307) 965-907. 58 II 19 OQ] ggo |] g10 80 O32 4:02) (964, || 805 69 o 8 0] 987 ) sare 74. O/AI O| 962: 1-906 62 1 8 45 984 | 894 go 120 0} 958 | 891 67a 2:10 ©j| 964 15845 15g I 33 30 | 954 | 889 | 65 3.930] 911 | 758 | 153 Ss 4 8 oO} 780 | 546 | 234 Mean ...... 965 | 897 63 |! Mean from goth.| 11 41 48 | 981 | 917 64. 115 9™ to | so 906 85 opr rs0) |. 1978.| “god 74 se And coilecting the average daily results of Table III. for +1 hour from noon, we obtain :— TABLE IV. Macon. M—D. 1869. Oct. 27. | 972 889 | 83 28. 946 $83 63 Mean 3S 978 902 76 |and == 1084, M which values of M—D and 7 are practically identical with those of Table IL. . (16) As regards the complete day-curve observed on November 4, it ] | 2d % - ‘ kia ee ee ee oe atl dhe 1870. ] Observations in India. 231 appears that while the radiation at both stations increases from 8 a.m. and 4 p.m. towards some time about noon, the difference M—D diminishes. In other words, the radiation at the lower station increases more rapidly than at the upper ; and while at both stations the change is more rapid in the afternoon than in the forenoon, the relative change between forenoon and afternoon is greatest at the lower station. (17) Mr. Hodgkinson, in his paper already referred to, quotes certain numbers obtained by Principal Forbes from his “ free hand curve” of ob- servations on the Faulhorn and Brienz, showing the relative intensity of the two stations. Calling his ratio BR the following may be contrasted :— By Mr. Forbes. From Table III., Nov. 4th, 1869. a SQ Cone SSS SSR Hour. ~ hm s Su S215 Y174 9 ORAS en ore 9 II 23 1°146 10 Wel Avera cetaceans 10 8 45 137 11 QAR Bera ah sito Il 14 22 1'097 12 Hees (ys eon osocudan Ol oe aO 1'081 I rol kee ee ceremaes r 8 45 1101 2 TODO Tp ccs see ce 2 O30 I'l4i 3 1 ah leone car 2) Ags 1°202 458" 0 I°429 where the heights of the stations are :— feet Waulhorn....... 8747 i ieee Brienz ........ ices ee Mussoorie .... 6937 } from the records of the Great Trigonometrical DST eS 2229 Survey of India. In conclusion I gladly acknowledge that I am much indebted to my friend Mr. Cole, not only for his skill and industry in taking the obser- vations at Dehra, but for his cordial cooperation in reducing and discussing them. Hoping you continue in the enjoyment of good health, I am, dear Sir, with kind wishes, Yours very truly, | J. H. N. HENNEssEY. General Sir Edward Sabine, K.C.B., &c., Pres, Roy. Soc., London. The record of actinometer observations has been posted in a separate packet *. The papers enclosed with this letter are the paper of actinome- tric curves and the result-abstract Table. [ * This record is preserved in the Archives for reference.—G. G. S.] Lieut. Hennessey on Aciinometrical Result-abstract of Actinometrical Observations at Mussoorie on an outer range of the Himalayas, and at Dehra in the Dehra Dhoon, made by J. H. N. Hennessey, Esq., and W. H. Cole, Esq., M.A., of the Great Trigonometrical Survey of India. Observations. Mean of the Mean results at Mussoorie observed with A and reduced to 32° Fahr. Mean results at Dehra observed with B and reduced to 32° Fahr. In terms In terms In terms In terms In | In apparent of A, of A, Nos. of A, of A, G@).| X times. glass on. glass off. glass on. glass off. October 27, 1869. he aay jos 3. | 2] 11 49 30 ris 924 1007 1S 804 876 selea OG 30 6 10 388 968 6 10 $29 904 Ares 4) OREO 6> 12 890 970 2/52 1 © 29-30 rq a7 863 941 tr 25 815 888 AN 3 4 O31 05) 13” 19 878 957 3}2]/ 945 30] 20 24} 885 965 Bes Wyn eg One Bg 73k 869 947 October 28, 1369. 4|3)|19 57 oO} 32 38 874 953 ORIG S.. Ou cok can alte ence eee Me cease 16 26 807 880 4) 3 | 11 20 0} 39 45 865 943 Regio dt 40101 AG feo 876 955 217 38 814 887 “SAMUS: Fa lee Paco Miata ae | I BE gia (Ra SU 27 a7 818 8g2 For 3ul 20m OC) $3. 594» 889 969 38 44] 810 833 [eats OP CARS IE Pict eee eet ema So a lcoraiat 38: 5 A7 796 868 Kpeseicn © 21 Or) 60. 68 851 928 48 56 811 884 eel en OP 3430 Paste Po eee cage Wi) Skee 56 64 812 385 Red 80543; 30. |5 69. 177 868 946 October 29, 1869. Sea ORO NRONN. detaches io cseseh ut as aces G5 75 822 896 CORES 0 SO Lo cewewct > Hime itonkieaee” Gui ieiee Sate Te O38 816 889 BM AC Piet ZO eax econs 4gobes Soss6o 83. 91 $21 895 SME ELBA BIO) ete inncm ced becase lye ceuacs g2 102 $27 gol Galas OV eu wecece sae te a pileisateie Mid bo dow aks 103 113 825 399 Zitat ar wges0u! 7s 82 903 984 Binlie “Cine ay. ae CO Mey Iemas Seemeyir scare a1 UR ear Og) Wea tea 107 III 821 895 Baas, YOl2a a0 83. 91 835 965 114/22 $32 907 vet he E32 SON enencrcdee lt: Penceee seas 122 128 821 895 Aes etirO patie IO tc Lanth noe halts oce chee aah) Ligstyaee 128 134 826 goo 6] 5 fez 0 jn 02 07, 879 958 ee 1 33 30.) 102 “110 875 954 BaZa. 233) 30. | | sotsscces pasts: saeaee 135 139 B05 877 Bee Se SO ieee Fieet | | gases | wan ee 140 148 733 853 Bee ORO! SO | ees s ees | sean) ( eennae 149 157 765 834 443 ga2z1 “0 ae eae ao oa | RES Se 157 163 739 806 October 30, 1869. A} 3] 11 40-0 | 133 119 899 980 164 170 337 gi2 64 63) At 48770 7 1 bss... aestiienenl ewes 164 174 845 921 5 | 4 | 11 43 30 | 111 119 902 983 64-5 O° 102 0)| 520 130 899 980 ole © 1 30 | 122 130 $96. 1g 77 175 183 $28 903 6) 5 re Maas (ae ©) “ESS, Maer er time Fame tesoe 175 185 831 906 Aa 3g OAT, wom at, 137 905 986 S42.) OO 8goama33 137 go2 983 186 190 $43 919 BS AO Oe Gee veer in| Asa swe ool cence 186 196 842 918 [ Dec. 22, : n = i, at , a ee Se — ss ag Bat BIE 1870.) Observations in India. 233° : Mean results at Mussoorie observed Mean results at Dehra observed + EES with A and reduced to 32° Fahr. with B and reduced to 32° Fahr. hao hin Mean of the In terms In terms In terms In terms apparent Nos. of A, of A, Nos. of A, of A, ©.| X. times. glass on. glass off. glass on, glass off. November 1, ee ET November 1, 1869.0 Anh 3 lr Bee Oh Paw acwasecee bP cutee ~ ir," se D = > g a) ~ 3 & S OOL\F Ite? DUPM IY YP 7 "g pus Y SioJOMIOUTZOV U99Mj04 sUOSIAudULOd Og SepIseg ‘BAyo( 4B GOP PUL o1OOSSN AT qe UdHV} OOM SUOIZBAIOSGO GIE “Ie UT ‘Joywo1S ACJ Sl [NSO v 1OJ SUOTJBAIOSGO Jo daqiunuU ay4 ‘{QAQMOY ‘BINAVSY ‘SUOFBAIOSqO-opeYys Z PUB -UNS F UBT} sso] JOU JO [NSAI ay} Sjuosetdor yuIod youd ‘G698t ‘19quIOAON JO YIP PUB 10G0}9O Jo YQZz OY} USIAJEq OPC ALOM SUOTIVAIOSGO TLL, *g194}0 OY} eytur UL WoIy WY} YSINTuTstp 07 aJoa10 B Aq Papunosins aie V7eP Yous TOF syutod jeuruii8; pue ‘Q[OAIO [VULULO} PUL [ELIT YOU OAD UMOYS ST UOLBAIISGO JO ojep oy, ‘eayod op saury pozdnas9jzur UL es0y} ‘o1xoossnyAT OF ureyzoddy soul, SnonuTzUOD Ul s9AINd 9. —*970NT \é is CaP4 4 é OL Y TULIP QUI bid Y YU ; i] 929} 6266 yooy Z8@9 * [eAd|-Bas ULAUT DAOGe qy soy 19 084 AB y es : 79+ + UTMUIAIL) JO JSG ‘SUO'T jOL 90 186 005 savage aie YUWON 3VT *elyod *a1100SSN JL ° ¢ DLYa(] pun IULOOSSTNIAT SIAUNY) J1.7OUW0UI20 fF & ‘ (SI? 88771D) 2S OOTE SY7UAL hAZIMIUNIJIP fe - to Thursday, s Recess hristma ‘ J ‘ned over the C joul ty then ad ocie The § January |: 1871. ) —) 1870.] Mr. G. Gore on Fluoride of Silver. 235 January 12, 1871. General Sir EDWARD SABINE, K.C.B., President, in the Chair. Prof. Benjamin Peirce (elected Foreign Member in 1852) and Col. J.T. Walker, R.E., were admitted into the Society. The following communications were read :— I. “On Fluoride of Silver.—Part II.” By Grorcr Gorg, F.R.S. Received September 22, 1870. (Abstract.) This paper contains an exhaustive account of the behaviour of argentic fluoride in vessels of platinum, carbon, and various fluorides in contact - with chlorine, bromine, and iodine at various temperatures. When argentic fluoride is completely decomposed by chlorine in platinum vessels at a red heat, the reaction agrees with the following equation : 4AgF+44Cl+ Pt=4AgCl, PtF,. Vessels of cryolite and of fluor-spar were found incapable of retaining argentic fluoride in a melted state. Other vessels were also made by melt- ing and casting various. mixtures of earthy fluorides at a high temperature ; and although forming beautiful products, probably capable of technical uses, they were not capable of retaining silver fluoride in a state of fusion. Numerous vessels were also made of seventeen different fluorides by moulding them in the state of clay and baking them at suitable tempera- tures; these also were found incapable of holding melted fluoride of silver. Argentic fluoride was only superficially decomposed by chlorine at 60° Fahr. during thirty-eight days. When heated to 230° Fahr. during fifteen days in a platinum vessel in chlorine, it was very little decomposed. Chloride of silver heated to fusion in a platinum vessel in chlorine corroded the vessel and formed a platinum-salt, as when fluoride of silver was employed. An aqueous solution of argentic fluoride agitated with chlorine evolved heat and set free oxygen, in accordance with the following equation :— SAgF+8C1+4H, O=5AgC1+3AgC1I0 +8 HF+0, or : 7Ag(1+AgClO, +SHF+0. Dry hydrochloric acid gas completely decomposed argentic fluoride in a melted state, but only acted upon it superficially at 60° Fahr. A satu- rated aqueous solution of argentic fluoride was not precipitated by chloric acid. Perfectly avhydrous fluoride of silver was only superficially decomposed by contact with bromine in a platinum vessel during thirty-six days at 60° Fahr., or during two days at 200° Fahr. Ata low red heat in vessels of platinum, argentic fluoride was completely decomposed by a current 236 Mr. C. F. Varley on the Discharge of Electricity [Jan. 12, of bromine vapour, a portion of its fluorine being expelled and a portion corroding the platinum and forming an insoluble compound of fluoride of platinum and bromide of silver. In carbon boats at the same temperature the whole of the silver-salt was converted into bromide, the boat being cor- roded and the fluorine escaping in chemical union with the carbon. The action of bromine on an aqueous solution of argentic fluoride was similar to the action of chlorine. A solution of argentic fluoride yielded copious pre- cipitates both with hydrobromic and bromic acids. Under the influence of a temperature of 200° to 600° Fahr. in closed platinum vessels, iodine very slowly and incompletely decomposes argentic fluoride without corroding the vessels, and produces a feeble compound of argentic iodide, fluorine, and iodine, from which the two latter substances are expelled at ared heat. Ata red heat in platinum vessels, iodine pro- duces argentic iodide, and in the presence of free argentic fluoride corrodes the vessels in consequence of formation of platinic fluoride ; iodine and fluorine pass away together during the reaction. In vessels of carbon at the same temperature argentic iodide is formed, the vessels are corroded, and a gaseous compound of fluorine and carbon is produced. By treating an aqueous solution of argentic fluoride with iodine, similar results are produced as with bromine and chlorine; a similar solution yields copious precipitates both with hydriodic and iodic acids. _ A mode of analysis of iodine is also fully described in the paper. A known weight of iodine was dissolved in absolute alcohol, a strong solution of argentic nitrate of known strength added to it, in portions at a time, with stirring until the colour of iodine exactly disappeared. The mixture was evaporated, the free nitric acid expelled by careful heat, and the residue weighed. The residue was then heated to fusion, to convert the iodate of silver into iodide, and again weighed. Two experiments of this kind yielded accurate results, and the process was easy and expeditious. II. “Some Experiments on the Discharge of Electricity through Rarefied Media and the Atmosphere.” By Cromwe.u FLEET- woop VartEy. Communicated by Prof. Stoxzs, Sec. R.S. Received October 5, 1870. After the labours of Mr. Gassiot, one approaches this subject with diffi- dence, lest he should appear to be attempting to appropriate the glory which so justly belongs to that gentleman and to Professor Grove. The nature of the action inside the tube is at present involved in considerable mystery, but some light is thrown upon the subject by the following experiments. Before describing them, however, the author wishes to ob- serve that he has seen Mr. Gassiot’s last paper*, and finds that, so far as regulating the strength of the current is concerned, he has been pro- ceeding in asimilar manner to the author. * Proceedings of the Royal Society, vol. xu. p. 329. 1871.] through Rarefied Media, &c. 237 The tube principally used in these experiments is shown full size in pho- tograph No. 1 (PI. II.); it contains two aluminium wire rings, the one ;4; inch in diameter, the other 5%, inch, and separated 58; inch: the tube was 14 inch in diameter, 34 inches in length ; it was one of Geissler’s manufacture, was very well exhausted, and professed to contain hydrogen. A U-shaped glass tube containing glycerine and water was placed in circuit. Two aluminium wires inserted in this tube gave a ready means of reducing or augmenting the resistance at pleasure. Glycerine affords an easy means of producing very great resistances. The battery used in this experiment was a Daniell’s battery, each cell having a resistanceof from 50 to 100ohms. The resistance of the glycerine- and-water tube was between 2 and 3 megohms ; this latter resistance was made large, in order that the resistance of the tube and battery might be neglected without entailing error. The following laws were found to govern the passage of the current :— Ist, each tube requires a certain potential to leap across; 2nd, a passage for the current having been once established, a lower potential is sufficient to continue the current; 3rd, if the minimum potential, which will maintain a current through the tube, be P, and the power be varied to P+1, P+ 2, &c. to P-+n, the current will vary in strength, as 1, 2, &e. n. Tables I. & II. (p. 242) illustrate this; there is a little irregularity in the figures due to the irregularity of the battery, although it was recharged for the occasion. It thus appears that a certain amount of power is necessary to spring across the vacuum; after that it behaves as an ordinary conductor, ex- cluding that portion of the battery whose potential is P, and which is used to balance the opposition of the tube. In these experiments P was 304 cells. ‘The tube in question could not be persuaded to allow a current of less than 323 cells to pass ; but when once the current had established a channel, on lowering the potential by short circuiting portions of the battery, so as not to break the circuit, the current would flow wlien the battery was reduced to 308 cells. By, however, passing a current from 600 cells, in the manner shown in PI. III. fig. 1, through the second tube, filled with pure glycerine, and offering several thousand megohms resistance, an extremely feeble current, too weak to affect the galvanometer, kept a channel open by its passage ; with this arrangement the figures in Table IT. were obtained, which are more regular at the commencement, and a power of P+1 would pass across the tube. The positive pole alone was observed to be luminous when the current was very minute, and the negative only was luminous when the current was strong. The following experiments were tried, and the results, which have been photographed, accompany this. A current was passed through the U tube and the vacuum ; the U tube contained pure glycerine, and had a very large resistance, which was gra- 238 Mr. C. F. Varley on the Discharge of Electricity [Jan. 12, dually reduced. At the commencement it was more than 10,000 Hee ONS 5 ; the upper or small ring was positive, the lower ring was negative. The power was so reduced that the faintest possible light only was visible ; in this case the positive wire alone was luminous, whether it were the large or small ring that was positive. No. 2 (Pl. II.) is a photograph of this. The light was so feeble that, though the experiment was conducted in a perfectly dark room, we were sometimes unaware whether the current was passing or not. An exposure of thirty minutes’ duration left, as will be seen, a very good photographic record of what was taking place; this means of viewing light too feeble for the eye may receive other applica- tions. The resistance was then reduced, when the light became much more brilliant,—a tongue of light projected from the positive pole towards the negative, the latter being still almost completely obscure. The light around the positive pole was to. all of our eyes white, while the projecting flame was a bright brick-red. This bright brick-red, however, possessed great photographic power, as will be seen by photograph No. 3. The negative wire at this stage began to show signs of luminosity. As the power was increased, the flame became detached from the positive pole, as shown in photograph 4. On still further increasing the power, the positive pole ceased to be luminous, as in photograph 5; and on still further increasing the power, by removing the U tube altogether, the phenomena presented themselves which are shown in photograph 6, in which the light surrounded the negative wire. The photograph shows a white flattened hour-glass, apparently detached from the wire ; to the eye, however, the wire appeared to be surrounded by a bright blue envelope z inch in diameter, which did not possess sufficient photographic power to leave a record of itself, while the red portion did so : this photograph was exposed only ten seconds to the light. A large condenser was now attached to the battery, and discharged through the tube (the condenser had a capacity of 27 microfarads) ; this was equivalent to a momentary contact with a battery of little or no re- sistance. The flash was exceedingly brilliant to the eye: it could be heard outside the tube with a sharp click ; the eye, however, was so dazzled as not to be able to see its shape. Photographs 7 a and 7 6 show that the light was confined entirely to the positive pole; thus, then, as the power is increased from nothing up- wards, the first pole to become luminous is the positive ; secondly, the two poles become luminous ; thirdly, the negative pole alone is luminous ; and fourthly, with au instantaneous discharge, the positive pole only is luminous. The eye and the collodion-plate do not, however, tell the same tale in photograph 6. When the resistance in the U tube was greatly reduced, and a galvano- meter (not very sensitive) was inserted, so that the chief resistance in circuit was that of the exhausted tube, as the potential was augmented cell Pit Proc. Roy Soc. Vol. amp. ° West ZC 1 W HY esley 1 ie ‘ West £C° imp ‘S7792 OOO | H Ss | fa roc, Foy. 50t, Vol. XIX (PUL ae Ss [auptaslizh 3. cr) ] i /, Wi . == —— i ee ) DIUIDYGE2GPL PRDOLO (2.14) Ss / f vi y \ R a : Nee recta, a ® —— ene s t / NYGON : | Slee | 28 VA | Peers YS d ons as Seu <<. Cajon suIt07kj, 6) —$<$<—$>-<<$———— RAO ee . N43 c i eee aac! LEAL LAS ) } eae Sere > Sy | fe cs N \ / E | & » MAI | i I Mh 38 N nL WH Wesley lith. Varley \ x 1871.} through Rarefied Media, &c. 239 by cell, the changes took place abruptly and suddenly. For example, when the power was so low that the positive pole only was visible, the current was feeble, and kept augmenting in power as cell after cell was added on. Suddenly the luminous red flame (phot. 3) made its appearance, and the galvanometer showed that the current had suddenly augmented three or four times in power. As the power was again further increased cell by cell, the current again steadily augmented in proportion, until the luminous tongue suddenly disappeared, and the appearance in 6 was shown, the galvanometer showing a still further sudden increase in the current. The phenomena shown in 4 and 5 can only be obtained by inserting a large resistance. Nature of the luminous cloud.— Plucker has shown that when such an exhausted tube, with a current through it, is placed between the poles of an electro-magnet, a luminous arch is produced, which arch follows the course of the magnetic rays. (See photograph 8, in which the negative pole was a small ring. Photograph 9 shows the arch when the large ring was negative.) As the electro-magnet is magnetized, the tube, which before was full of a luminous cloud, is seen gradually to change ; the magnet gathers up this diffused cloud, and builds up the arch shown in 8 and 9. Inasmuch as the electricity was passing in a continuous current from the battery, from wire to wire, it is evident the light is projected right and left into those parts of the tube where there is no electric current flowing. To endeavour to ascertain the nature of this arch, a tube (Pl. III. fig. 2) was constructed. A piece of tale, bent into the form U, had a fibre of silk stretched across it ; on this fibre of silk was cemented a thin strip of tale, 1 inch in length, +45 inch broad, weighing about 7 of agrain. The tube was sealed up and exhausted; carbonic acid and potash were used to get a high vacuum. When the magnet was not magnetized, the passage of the current from wire to wire did not affect the piece of tale. When the magnet was charged, and the luminous arch was made to play upon the lower portion of the talc, it repelled it, no matter which way the electric current was passing. When the tube was shifted over the poles of the magnet so as to project the luminous arch against the upper part of the talc, the upper end of the tale was repelled in all instances; the arch, when projected against the lower part of the tale, being near the magnet, was more concentrated, and the angle of deviation of the talc was as much as 20°. When the upper part of the arch, which was much more diffused, was thrown upon the upper part of the talc, it was repelled about 5°. This experiment, in the author’s opinion, indicates that this arch is com- posed of attenuated particles of matter projected from the negative pole by electricity in all directions, but that the magnet controls their course; and 240 Mr. C.F. Varley on the Discharge of Electricity [Jan. 12, these particles seem to be thrown by momentum on each side of the nega- tive pole, beyond the limit of the electric current. This arch requires time for its formation, for when a charged condenser is discharged through the tube no arch is produced. ‘he arch from the negative pole is a hollow cylinder; the little talc tell-tale against which the arch was projected cut out the light, and a corresponding dark space existed throughout the remainder of the course of the arch. There was on the tale, at the spot where the arch struck it, a little bright luminous cloud, as though the attenuated luminous vapour were condensed by this material obstruction. Great care had been taken not to let the arch strike the single filament of silk which suspended the tale. Having demonstrated that the tale was repelled as described, the arch was allowed to play against the silk fibre, which the author expected would have been instantly burnt ; such, however, was not the case. Even when a powerful induction-coil replaced the battery, the fibre remained unhurt. Comparison of the above Phenomena with Discharges between the Poles of a Holtz’s Machine in air. In the first part of this paper four different kinds of discharges were de- scribed in vacuo. With a ‘Holtz’s”’ machine, which will give 11-inch sparks in the air, four well-marked different kinds of discharge have been ob- tained én the air; one of which, the author thinks, will explain the curious and rare phenomenon known as “ ball lightning.”’ In the experiments hereafter referred to, the condensers were in all cases attached to the ‘‘ Holtz’s”” machine. The first discharge is the long 11-inch zigzag spark or lightning-flash ; the second is the well-known “ brush,”’ which is best obtaimed by connecting the negative pole of the ‘ Holtz’s”’ machine to the earth ; the third kind of discharge is a hissing red flame, + inch in length, playing about the negative pole, the positive pole being scarcely luminous at all, and if luminous, at one or two points only; the fourth or most remarkable phenomenon is best obtained in the following manner (it should be understood that the brass balls on each of the poles are about an inch in diameter) :—Tie to the negative pole a small thin strip or filament of wood, 3 inches in length, and bent so as to project on each side of the negative pole, and a little beyond it towards the positive. On rotating the machine, two bright spots are seen upon the positive pole. If the positive pole be made to rotate upon its axis, the luminous spots do not rotate with it ; if, however, the negative pole, with its filament of wood, be rotated, the spots on the positive pole obey it, and rotate also. The in- sertion of a non-conductor, such as a strip of glass, in front of the pro- jecting wooden end, obliterates the luminous spot on the positive pole. When the author first discovered this, he, seeing apparently pieces of dirt on the positive pole, wiped it clean with a silk handkerchief, but there 1871. ] through Rarefied Media, &c. 241 they remained in spite of all wiping ; he then examined the negative pole, and discovered a minute speck of dirt corresponding to the luminous spots on the positive pole. When the filament of wood is removed from the negative pole, there is sometimes a luminosity or glow over a large portion of the surface of the positive ball. If in this state three or four little pieces of wax, or even a drop or two of water, be placed upon the negative pole, corresponding non- luminous spots will be found upon the positive pole, which rotate with the former, but do not with the latter. It is therefore evident that there are lines of force existing between the two poles, and by these means one is able to telegraph from the negative to the positive pole to a distance of 8 inches through the air, without any other conductor than that which the electrical machine has constructed for itself across the non-conducting gas. The foregoing seems to the author to give a possible explanation of *‘ball-lightning.” Ifit be possible for there to be a negatively electrified cloud sufficiently charged to produce a flash from the earth to the cloud, a point in the cloud would correspond to the wood projection on the negative conductor: if such a cloud exist, a luminous spot would be seen moving about the surface of the earth, corresponding to the moving point of cloud over it, and thus present phenomena similar to those described by the pri- vileged few who have witnessed this extraordinary natural phenomenon. The following experiment shows that, prior to the passage of the electric spark, a channel is prepared for this spark to pass. The positive and negative balls of the machine were separated to a distance of 6 or 7 inches, and a common candle-flame was placed midway be- tween them. On rotating the machine, the flame was drawn out on each side just prior to the passage of the spark, as shown in the accompanying sketch (PL III. fig. 3). Sometimes it extended to a width of 5 or 6 inches; this took place every time the spark passed. It is well known that the dura- tion of this spark is less than the ha part of a second; the flame occu- pied the 3 or ;}, part of a second in flying out to make the conducting chan- nel through which the discharge went. The author has been informed more than once, by captains of vessels, that when men have been struck by lightning a burn has been left upon the skin of the same shape as the object from which the discharge flew. In one instance he was informed that some brass numbers attached to the rigging, from which the discharge passed to the sailor, were imprinted upon his skin. , It is now seen that this is perfectly possible if the discharge be a nega- tive one —that is, if the man be+ to the brass number. VOL. XIX. U 242 Discharge of Electricity through Rarefied Media. [Jan. 12, TaBLe I. ik. oO 3. 4, Cells of Daniell’s Observed Deflections of M 3rd Col. Battery, P+-n. Reflecting Galvanometer. can. Idivided by x. 307=P+ 3 0 0 0 0) 0 0 808=P+ 4 5 54 5 5i dF 1:3 309=P+ 5 9 9 9 9 9 1:8 310=P+ 6 12, 12: 12 123 124 2:04 3ll1=P+ 7 14 14 a “i 14 2 312=P+ 8 16 a ay via 16 2 818=P+ 9 17i—s 18 18 at 173 1:97 314=P+10 193 193 aye nae 192 1:95 31l5=P+11 214 21 22 213 214 1:95 316=P+4+12 234 233 232 a 234 1:96 317=P+13 254 tae ee ts 254 1:96 318=P+414 274 a =i ee 274 1:97 319=P+4+15 292 ee Tih panes Pee 292 1:97 320= P+16 381i 313 «31 3l 31; 1:95 *393=P+4+19 3874 = 338 37 374 37k 1:97 325= P+21 40% 41 403 Be 4132 1:94. 330= P+26 51 51 75 ro 51 1:96 335=P+31 604 6024 e; 4 604 1:95 840= P+36 70 70 fs at 70 1-94. 345 =P+41 794 794 Be ae 793 1:94 850=P+46 89 89 ase pod &9 1:94. 355=P+51 98 983 ae ae 983 1:93 360=P-+56 108 108 ae ie 108 1:93 865=P-+61 118 #118 a a 118 1:94. 370=P+66 1238 128 * a 128 1:94 375=P+71 1389 #8140 As wh 1393 1:96 380=P+76 150 150 bi a 150 1:97 Taste IT. 304=P+ 0 0 ane 0 0 3805=P-++ 1 2 2 2 2 a06=P-+ 2 4 4 4 2 307=P-+ 3 6 6 6 2 Bus=P- 4 8 8 8 2 309=P+ 5 10 10 10 2 310=P+ 6 12 12 12 2 320=P+16 314 82 ae ue 312 1:97 330=P+26 ol 51 ay) ea 51 1:96 340—=P-+36 71 713 a A (al 1:97 * This power (323) was the lowest at which the current would jump. 1871.] Polarization of Metalhe Surfaces in Aqueous Solutions. 243 III. “ Polarization of Metallic Surfaces in Aqueous Solutions, a new Method of obtaining Electricity from Mechanical Force, and certain relations between Electrostatic Induction and the Decomposition of Water.” By CromweELt FLEETWOOD VaRLEY. Communicated _by Prof. Sir W. Toomson, F.R.S. Received October 5, 1870. (Abstract. ) Platinum plates immersed in sulphuric acid and water, as in a decompo- sition-cell, require a potential of about 1°7 Daniell’s cell to decompose the water ; with potentials of less amount the platinum plates can be charged and discharged like condensers. They have enormous electrostatic capa- city. Mercurial surfaces equally admit of polarization with hydrogen. A surface of mercury in dilute sulphuric acid, when made negative to the water by means of a powerful battery, flattens out. Ifthe mercury be replaced by an amalgam of proper consistency, the flattening out is increased ; the re- versal of the current restores the amalgam to its original dimensions. By reversing the process, electric currents can be obtained from mechanical force. A large vessel on a board has within it two shallow funnels, which are connected by means of glass tubes with similar vessels outside of the large one. Pure mercury is poured into the funnels until they and the outside vessels are one-third filled. By tilting the board, mercury runs into the one funnel and out of the other, and thus the surface in the one is made to increase while that in the other decreases. Dilute sulphuric acid is poured into the larger vessel so as to cover the two funnels; the latter are connected together through a galvanometer. If the mercury be pure and free from polarization, the tilting of the board produces no electric current. On polarizing one of the surfaces with hydrogen by a battery, it gives rise to a current through the galvanometer, and thus shares the polarization over the two surfaces. If the battery be removed, on augmenting the one surface and diminishing the other, a cur- rent of electricity is seen to pass through the galvanometer. A convenient method of showing this experiment on a large scale is to procure a gutta-percha trough 4 inches deep and 4 by 2 inches broad. A partition of the same material 2 inches high divides the lower half into two separate chambers: these are partly filled with mercury; amalgamated platinum plates, hung from a balance-lever, dip into the mercury. On depressing one set of plates the others are elevated, and thus the mercurial surface exposed to the fluid is alternately augmented and diminished to a large amount. Twelve of these arranged in series give a current of rather more potential than one cell of Daniell’s battery when the mercury is polar- ized with hydrogen. The addition of a minute fragment of zinc to the mercury maintains the polarization for a very long time, and the power is considerably increased thereby. When a large surface of mercury (25 cir- cular inches) has been polarized with a power of half a Daniell’s cell and is rapidly reduced to the diameter of 2, inch, by letting the mereury flow out u 2 244 Mr. C. F. Varley on Polarization of [Jan. 12, of the funnel, some bubbles of hydrogen gas appear just as the last of the mercury is running out, the decrease of surface evidently augmenting the potential sufficiently to decompose the water: floating a small piece of platinum on the mercury renders this phenomenon much more distinct. All attempts to polarize the mercury with oxygen have failed to give a current. . By depolarizing the mercury with a battery until no current is generated by varying the dimensions of the exposed mercury surface, a me- tallic surface neutral to the fluid is obtained. The second part of the paper refers to the electrostatic capacity of plati- num plates in dilute acid and water. In order to determine this point, it is necessary to use sensitive, rapidly oscillating, reflecting galvanometers of very small resistance. The author has succeeded in measuring the charge which a square inch of platinum ex- posed to another square inch of platinum surface receives from potentials varying from 0:02 of a Daniell’s cell up to 1°6 Daniell’s cell. From a po- tential of 0:02 to 0°08 the capacity remains sensibly constant; that is, the discharge from the plates varies directly as the potential. When the potential increases beyond 0:08, the charge which the plates receive in- creases in a greater ratio, the capacity being 3°3 (in one experiment) and 3°1 (in another experiment) times as great with a potential of 1:6 as it was with the potential of 0:1. There is great difficulty attending accurate determination of the latter amounts ; but the author expects that this increase of capacity will be found to vary as the square root of the potential. The capacity of the platinum plates with varying powers is shown in the accompanying Tables. The author thinks these experiments tend to show that the fluid does not actually touch the platinum plate, but is separated from it by a film, which film, if a pure gas, must be less than the =e part of an inch, when very small potentials are used. This distance decreases as the poten- tial rises. Inasmuch as two surfaces equally electrified with the opposite electricities attract each other with a power varying inversely as the square of the distance, the experiment would seem to indicate that at very small distances the platinum repels the water with a power varying inversely as the cube of the distance. The phenomena of electrification render accurate determinations of the capacity extremely difficult. The fact of the phenomena of electrification being present, leads the author to think that the separating film (Gf such a film exists) is not a pure gas, but has five or more times as much electrostatic capacity as pure gas. A useful inference drawn from the above experiments is the impossibility of working through any considerable length of uninsulated wire in the ocean. The French Atlantic cable from Brest to St. Pierre works, upon the average, tea words per minute; the author calculates that a solid con- ductor of the same weight per mile as that used between the above stations must be reduced to a length of less than 1100 yards in order that the rate of signalling through it shall be not slower than through 2500 miles of 1871.] Metallic Surfaces in Aqueous Solutions. 245 the same conductor insulated ; and the bare wires can only be practically worked on circuits not exceeding a mile. Taste I. Two platinum bulbs about 0°75 inch in diameter in dilute saahere acid. Owing to the large resistance (1000 Ohms) used in R and R’, the actual potential is uncertain in this experiment, because the conduction across the fluid reduces it. is 2. ey 4, 5. 6. rie Mean Potential divided by in terms | Duration Swing of reflecting Current Mean potential | Approxi- of acell jof electrifi- galvanometer hy the after minus the | and 100 |mate capa- of cation in discharge of the bulbs magnet |remaining| to give city in Daniell’s | seconds. on raising the key. came to | current, | relative micro- battery. rest. capacity farads. for various potentials. 0-02 10 LE oe a 4 | ; ai of of 2 Oh ; 2 1 348 0-04 10 42 42 42 43 - 4 1 ‘ 0:06 10 64 6 6h 62 : 6 1 : i 2 a ry - oe eee : ; ie 102 0p 365 0-16 10 18 17% 18 es . | pee yee : } 163 | 1-09 379 0-2 10 24 24 24 13 S 20 24 24 24 ee | 2am 1-12 390 : 30 24 24 24 2 0-4 10 Idee IS 30S 2k | A: 20 D8... 58 4 | DOF 1°39 484 3 30 Romo tommnaaa (| » 0-6 10 105 1053 104 %9 . 20 105 104 105 | 1043 ee 606 A 30 104 105 103 23 08 10 164.163 162 162 3 P 20; | 162,162 4161 » 159 1-99 693 30 162 162 161 0 1:0 10 230 235 230 280 5 - 20 232 231 230 231 ‘5 226 2°26 786 30 | 231 231 7 12 30 318 320 314 14 303 2°53 880 *1-4. 30 440 446 451 23 426 3°04 1057 EG 30 about 603 30, 41, 52) 562 35 1218 * Last three readings doubtful, the current remaining after the discharge being con- siderable. The true reading would be Bila than indicated. $$$ 0-02 pens REC a ee (eer0S 311 0:04 Spare inca 3 2 : 0:06 Baie Ae ei a 42 i ‘ 0:08 Gia) Ger Gyn To ag 6 ss f 0-10 par art tye Malia Ma eae i ‘ f 0-2 Mee ORO TAR YD oS hc ele : 0-4 De DON ISU Ue a aie 29 4 06 Big eyeh date kis) Recah La B3ue |, 08 DOR Donk Dom wh eo 58 : ‘ 1-0 2 eT To ee hee 73 : : 1-6 Bar hase Elton whl one 116 ‘ ; 2:0 ge od 1 oa Cm 143 i ‘ The condenser of 311 microfarads capacity consisted of 24,300 square feet of metal surface insulated by thin paper and paraffin wax. 246 Mr. W.K. Parker on the [Jan. 19, TaBLe II. Two platinum plates in acid and water, each exposing 1 square inch surface. The resistance of R+R’=100 Ohms in this Table; by experi- ment the potential of the two cells was found to be reduced 8 per cent., and was therefore very nearly 200 Ibs. instead of two cells Daniell’s. : Ratio of A 4 : C t : i mate aime of Throw of aE by discharge remaining Porehcan cape Meee tent: i ; tes. t ‘ ae he: tion. a discliarpe: current. ae farads. seconds. 0 10 LO QO" 9 1 i Bo 1g 19. M19 a 18. bie 0:4 10 45 46 46 3 A 20 46 46 z 43 1:2 210 0:8 10 175 170 170 165 FL 159 2-2 3885 1:0 10 230 228 226 18 210 2°33 408 *1°2 10 310 308 3iil 22 288 26% 467 #14 10 373 380 382 30 350 pth 484 ¥1°6 10 460 460 467 475 30 428 3:10 542 Condenser of 311 microfarads. 0:2 32 32 32 0) 32 1 ou 0:4 63 64 634 ” 63% ” ” 0°8 127 127 ” 127 ” ” 1:0 159 159 9 159 ” ” 1:2 188 187 189 % 188 ” ” 1-4 220 220 221 * 220 an » 16 252 254 252 254 45 253 ” ” 1:8 284 283 284 x 284. > ” 2:0 316 317 317 » 317 ” ” * These readings are uncertain, being obliged to guess how much current remained after the image had swung out and back, its momentum lasting longer than with smaller deflections; the true reading would therefore be greater than those observed. January 19, 1871. General Sir EDWARD SABINE, K.C.B., President, in the Chair. Prof. Alfred Newton was admitted into the Society. The following communications were read :— I. “ On the Structure and Development of the Skull of the Common Frog (Rana temporaria).”’ By W. Kircunn Parker, F.R.S. Received October 10, 1870. (Abstract.) At the close of my last paper “‘ On the Skull of the Common Fowl,” I spoke of bringing before the Royal Society another, treating of that of 1871.] Skull of the Common Frog. 24:7 the osseous fish. I was working at the early conditions of the salmon’s skull at the time. I was, however, led to devote my attention to another and more instruc- tive type early in the following year ; for it was then (January 1869) that Professor Huxley was engaged in preparing his very important paper “ On the Representation of the Malleus and Incus in the other Vertebrata”’ (see Zool. Proc. May 27, 1869). In repeating some of his observations for my own instruction, it occurred to me to renew some researches I had been making from time to time on the frog and toad. The results were so interesting to us both, that it was agreed for me to work exhaustively at the development of the frog’s skull before finishing the paper on that of the salmon. On this account Pro- fessor Huxley mentions in his paper (op. cit. p. 406) that he leaves the Amphibia out of his demonstration, and that they are to be worked out by me. The amount of metamorphosis demonstrable in the chick whilst enclosed in the egg suggested a much more definite series of changes in a low, slow-growing Amphibian type. I think that this has been fully borne out by what is shown in the present paper. The first of the ten stages into which I have artificially divided my sub- ject is the unhatched embryo, whilst its head and tail project only mode- rately beyond the yelk-mass. Another stage is obtained by taking young tadpoles on about the third day after they have escaped from their glairy envelope; a few days elapse between the second and third stages, but a much longer time between the third and fourth, for the fourth stage is the perfect tadpole, before the limbs appear and whilst it is essentially a fish with mixed Chimeroid and Myxinoid characters. Then the metamorphosing tadpole is followed until it is a complete and nimble frog, two stages of which are examined ; and then old individuals are worked out, which give the culminating characters of the highest type of Amphibian. The early stages were worked out principally from specimens hardened in a solution of chromic acid; and the rich umber-brown colour of these preparations made them especially fit for examination by reflected light. Without going further into detail as to the mode of working my subject out, and without any lengthened account of the results obtained, I may state that the following conclusions have been arrived at; namely, that the ’ skull of the adult is highly compound, being composed of :— Ist. Its own proper membranous sac ; 2nd. Of a posterior part which is a continuation, in an unsegmented form, of the vertebral column ; 3rd. Of laminz which grow upwards from the first pair of facial arches, and which enclose the fore part of the membranous sac, just as the “ in- vesting mass ”’ of the cranial part of the notochord invests the hinder part. 4th. The ear-sacs and the olfactory labyrinth become inextricably com- bined with the outer case of the brain. And oth. The subcutaneous tissue of the scalp becomes ossified in certain 248 Mr. H. Mance on the Measurement (Jan. 19, definite patches; these are the cranial roof-bones. Around the mouth _ there are cartilages like those of the Lamprey and the Chimera; but these yield in interest to the proper facial bars, which are as follows, namely :— First pair, the “trabecule.” Second pair, the mandibular arch. Third pair, the hyoid arch. And fourth to seventh pairs: these are the branchials. : These are all originally separate pairs of cartilaginous rods; and from these are developed all the complex structures of the mouth, palate, face, and throat. The pterygo-palatine arcade is merely a secondary connecting bar developed, after some time, between the first and second arches. Meckel’s cartilage arises as a segmentary bud from the lower part of the second, and the ‘stylo-cerato-hyal,” as a similar secondary segment, from the third arch. By far the greater part of the cranium (its anterior two-thirds) is deve- loped by out-growing lamine from the trabeculz, which after a time be- come fused with the posterior or vertebral part of the skull. When the tadpole is becoming a frog, the hyoid arch undergoes a truly wonderful amount of metamorphosis. The upper part, answering to the hyomandibular of the fish (not to the whole of it, but to its upper half), becomes the “ incus,” and a detached segment becomes the “ orbiculare,”’ which wedges itself between the ineus and the “stapes.” The stapes isa “bung” cut out of the “ ear-sac.” The stylo-cerato-hyal is set free, rises higher and higher, and then articu- lates with the “ opisthotic ” region of the ear-sac ; in the toad it coalesces therewith, as in the mammal. The lower part of the hyomandibular coa- lesces with the back of the pair of the mandibular arch; and the “sym- plectic ” of the osseous fish appears whilst the tadpole is acquiring its limbs and its lungs, and then melts back again into the arch in front; it is re- presented, however, in the bull-frog, but not in the common species, by a distinct bone. This very rough and imperfect abstract must serve at present to in- dicate what has been seen and worked out in this most instructive vertebrate. II. “ Method of measuring the Resistance of a Conductor or of a Battery, or of a Telegraph-Line influenced by unknown Earth- currents, from a single Deflection of a Galvanometer of unknown Resistance.” By Henry Mancs, Superintendent Mekran Coast and Persian Gulf Telegraph Department, Kurrachee. Commu- nicated by Sir Wm. Tuomson. Received January 12, 1871. “The resistance of each part of a circuit, such as that shown in fiz. 15 being known, the influence exercised by the shunt A B, as well as the 1871.] of Electrical Resistance. 249 total resistance of the whole between and y, can be easily ascertained by simple and well-known formule. Rieck. | G 1 ¥, i RR PROS EEE eras De im & 13} 48 958 mim But let a leakage 7, which we will suppose gives perfect earth, be applied at some point in the shunt A B, the deflection previously produced on G by a current arising in L will probably be considerably changed. I say probably, because by sliding the leakage r along the whole length of the shunt, we shall at last find a point Zat which the needle will return to its original deflection ; the position of Z being ascertained, any resistance varying from infinity to “‘dead earth’? may be applied without causing any change in the deflection of the needle. It is evident that, although the total resistance of the circuit between x and y has been lessened by the insertion of the leakage, a proportionately larger amount of current is diverted from the galvanometer by that part of the shunt between L and the leakage at Z. Presuming the electromotive EK in L to remain constant, and taking 7r=0, we have the intensity of the current passing through G represented by the equation E ee Na Ra cel Noe { 7 Ga GaseBy A+B } but after r is connected, the equation becomes E RB RB ; Bee eg Geen Se eam) Sed AG eee = == ng As the condition that the galvanometer deflection remains unchanged, the first of these equations must be equal to the second, from which we obtain the formula A ‘Be the resistance G being immaterial. It will therefore be seen that R always bears the same proportion to L that B does to A, the latter branches bearing some analogy to the proportion-coils of a Wheatstone testing bridge. Under certain circumstances a test might be taken without any battery L=R. 250 Mr. H. Mance on ihe Measurement (Jan. 19, at all. In asubmerged cable there is frequently sufficient earth-current to supply the electromotive force in the branch L ; if not, a small battery can be inserted to maintain a steady current, and the internal resistance of the cells afterwards deducted. The polarization-current from a leakage of low resistance in a cable would enable us to find the resistance from either side through the fault without the application of a battery. And, lastly, this method may be used to ascertain the internal resistance of a battery. The above method occurred to me about two years since during some experiments made to determine the resistance of the bridge-circuit and the exact proportion of current traversing each branch of the Wheatstone balance when the potentials at W and Z are unequal. Fig. 2. If I equals the intensity of the current at « or y, and 2,, 7, 2, ty 2, the intensities in the sections G, R, A, 7, B, then G.(B+R+r)+BR SS SS SS l= A (B+ R+7)+ Br Us z, PPO ceo So Ss (1) AC (BEE Reb) le i G.(B+R+r)+BR + i, «bey a ts ae ( ) Re (AbD PG) 1 8G a2 (3) r.(A+B+G)+AB i, 7 (A+B+G)+BA rae ms Ro CA++) 256 jo ae B(R4r)+(B+R+1) (AFG) _1 2 Gr—AR 7, ae Or if the current in the branch B passes from W to Z, AR—Gr should be substituted for the denominator of the last equation. Equations (1), (2), (3), and (4) give the shunt-coefficient of the respec- tive branches A, G, r, R; thus if G were a galvanometer, the strength of the deflection recorded multiplied by equation (1) would give the value of intensity I. If, then, we consider G a galvanometer and the resistance r a leakage applied at Z, we have a similar diagram to that given in fig. 1; and the first of the five equations given above will enable us to determine the shunt- coefficient for the part A which lies between L and the leakage at Z. 1871.| of Electrical Resistance. 251 Now this, together with the plan of testing described in the first para- graph, suggests an easy method for ascertaining by calculation the com- bined resistance of any system of derived circuits connected in the form of the Wheatstone’s parallelogram ; thus if I wish to know the resistance offered to the passage of acurrent between a and y in fig. 3, I can find it Fig. 3. ; 200 ca 200 & R ee B of, mmm 7 Ee > so in the following manner. First assume the existence at 2 of a sixth branch bearing (in resistance) the same proportion to R that A does to B; that is to say, the supposititious braach A =R.—. : B Now disconnect r from the point Z, and we have again a diagram similar to that in fig. 1; and as we have provided that == a the connexion or disconnexion of r at the point Z will make no difference whatever in the quantity of current passing from L into the branch G. I may therefore assume that, although the total resistance of the circuit between g and y has been decreased, the branch A has at the same time been able to divert a proportionately greater amount of current from the side G, in which the intensity remains unaltered. If, then, R, equals the resistance between g and y when the branch r is dis- connected, S, the shunt-coefficient of A B which forms a shunt in the absence of r, R, the resistance between g and y after r is connected at Z, S, the shunt-coefficient for the part A ascertained by equation (1), we have R, x S —Rh, x Se ne ues 2 Bo R and R, minus the supposititious branch (=) will give the required com- bined resistance of the circuit between x and y. Let R, be the combined resistance. Commencing with the equation RA | G.(A+B) \ A+B+G roe ie, kA, G(BTE+)+BR | eae A.(B+R+7)+Br 252 On the Internal Resistance of a Multiple Battery. [Jan. 19, we obtain R.(A+B+G) = B oa _ RA G.(B+R+r)+BR | | ‘S A. (B+R+4r)+Br If the potential at Z equalled that at W, the formula R _(G+R).(A+R) ; G+R+A+r would of course be sufficient. III. “ Measurement of the Internal Resistance of a Multiple Battery by adjusting the Galvanometer to Zero.” By Henry Mancz. Communicated by Sir Wo. Tomson, LL.D.,F.R.S. Received January 12, 1871. The following method of taking the internal resistance of a battery will be found to give excellent results when several cells are to be tested. Take one element from the rest of the cells and arrange the circuit as in the annexed figure. Connect the poles of the battery under observation by a shunt 8S, and adjust the resistance of the latter till zero is obtained on the galvanometer. E Let E be the number of cells tested, ating, + »* pp e number of cells opposed, s A S = resistance of shunt, R= internal resistance of E. Then R—s# _s. é In practice I usually returned the detached cell to the battery when Sx E gave the internal resistance of the whole within a fraction of a unit. It is assumed that the electromotive force in e equals that of the whole battery multiplied by - ; the chance of error on account of this not being exactly the case would be lessened by detaching a larger number of cells than one when the internal resistance of the remaining portion would be given by the first formula. ce ae” ane 1871.] On a Constant Form of Daniell’s Battery. 253 IV. “Modification of Wheatstone’s Bridge to find the Resistance of a Galvanometer-Coil from a single deflection of its own needle.” By Prof. Sir Witx14am Tuomson, F.R.S. Received January 19,1871. Tn any useful arrangement in which a galvanometer or electrometer and a galvanic element or battery are connected, through whatever trains or network of conductors, let the galvanometer and battery be interchanged. Another arrangement is obtained which will probably be useful for a very different, although reciprocally related object. Hence, as soon as I learned from Mr. Mance his admirable method of measuring the internal re- sistance of a galvanic element (that described in the first of his two pre- ceding papers), it occurred to me that the reciprocal arrangement would afford a means of finding the resistance of a galvanometer-coil, from a single deflection of its own needle, by a galvanic element of unknown re- sistance. The resulting method proves to be of such extreme simplicity that it would be incredible that it had not occurred to any one before, were it not that I fail to find any trace of it published in books or papers ; and that personal inquiries of the best informed electricians of this country have shown that, in this country at least, it is a novelty. It consists simply in making the galvanometer-coil one of the four conductors of a Wheatstone’s bridge, and adjusting, as usual, to get the zero of current when the bridge contact is made, with only this difference, that the test of the zero is not by a galvanometer in the bridge showing no deflection, but by the galvanometer itself, the resistance of whose coil is to be measured, showing an unchanged deflection. Neither diagram nor further explana- tion is necessary to make this understood to any one who knows Wheat- stone’s bridge. V. “Qn a Constant Form of Daniell’s Battery.” By Prof. Sir Wixti1aM Tuomson, F.R.S. Received January 19, 1871. Graham’s discovery of the extreme slowness with which one liquid diffuses into another, and Fick’s mathematical theory of diffusion, cannot fail to suggest that diffusion alone, without intervention of a porous cell or membrane, might be advantageously used for keeping the two liquids of a Daniell’s battery separate. Hitherto, however, no galvanic element with- out some form of porous cell, membrane, or other porous solid for sepa- rator, has been found satisfactory in practice. The first idea of dispensing with a porous cell, and keeping the two liquids separate by gravity, is due to Mr. C. F. Varley, who proposed to put the copper-plate in the bottom of a jar, resting on it a saturated solu- tion of sulphate of copper, resting on this a less dense solution of sulphate of zinc, and immersed in the sulphate of zinc the metal zinc-plate fixed 254 Sir William Thomson on a [Jan. 19, near the top of the jar. But he tells me that batteries on this plan, called ** sravity-batteries,” were carefully tried in the late Electric and Inter- national Telegraph Company’s establishments, and found wanting in economy. ‘The waste of zinc and of sulphate of copper was found to be more in them than in the ordinary porous-cell batteries. Daniell’s batteries without porous cells have also been tried in France, and found unsatisfactory on account of the too free access of sulphate of copper to the zine, which they permit. Still, Graham’s and Fick’s measurements leave no room to doubt but that the access of sulphate of copper to the zinc would be much less rapid if by true diffusion alone, than it cannot but be in any form of porous-cell battery with vertical plates of copper and zinc opposed to one another, as are the ordinary telegraphic Daniell’s batteries which Mr. Varley finds superior to his own ‘‘ gravity-battery.” The comparative failure of the latter, there- fore, must have arisen from mixing by currents of the liquids. All that seems necessary, therefore, to make the gravity-battery much superior instead of somewhat inferior to the porous-cell battery, is to secure that the lower part of the liquid shall always remain denser than the upper part. In seek- ing how to realize this condition, it first occurred to me to take advantage of the fact that saturated solution of sulphate of zinc is much denser than saturated solution of sulphate of copper. It seems* that, at 15° tempera- ture, saturated aqueous solution of sulphate of copper is of 1°186 sp. gr., and contains in every 100 parts of water 33:1 parts of the crystalline salt ; and that at 15° the saturated solution of sulphate of zine is of sp. gr. 1:44, and contains in every 100 parts of water 140°5 parts of sulphate of zinc, both results being from Michel and Krafft’s experiments+. Hence I made an element with the zinc below; next it saturated solution of sul- phate of zinc, gradually diminishing to half strength through a few centi- metres upwards ; saturated sulphate of copper resting on this; and the copper-plate fixed above in the sulphate-of-copper solution. In the be- ginning, and for some time after, it is clear that the sulphate of copper can have no access to the zinc otherwise than by true diffusion. I have found this anticipation thoroughly realized in trials continued for several weeks ; but the ultimate fate of such a battery is that the sulphate of zine must penetrate through the whole liquid, and then it will be impossible to keep sulphate of copper separate in the upper part, because saturated solution of sulphate of zine certainly becomes denser on the introduction of sul- phate of copper to it. To escape this chaotic termination I have intro- duced a siphon of glass with a piece of cotton-wick along its length inside it, so placed as to draw off liquor very gradually from a level somewhat nearer the copper than the zinc; and a glass funnel, also provided with a core of cotton-wick, by which water semisaturated with sulphate of zine may be continually introduced at a somewhat lower level. A galvanic * Storer’s Dictionary of Solubilities of Chemical Substances. Cambridge, Massa - chusetts: Sever and Francis, 1864. {+ Ann. Ch. et Phys. (3) vol. xli. pp. 478, 482: 1854. 1871.] Constant Form of Daniell’s Battery. 255 element thus arranged will undoubtedly continue remarkably constant for many months; but it has one defect, which prevents me from expecting permanence for years. The zine being below, must sooner or later, ac- cording to the less or greater vertical dimensions of the cell, become covered with precipitated copper from the sulphate of copper which finds its way (however slowly) to the zinc. On the other hand, if the zinc be above, the greater part of the deposited copper falls off incoherently from the zine through the liquid to the copper below, where it does no mischief, provided always that the zinc be not amalgamated,—a most important con- dition for permanent batteries, pointed out to me many years ago by Mr. Varley. Placing the zinc above has also the great practical advantage that, even when after a very long time it becomes so much coated with metallic copper as to seriously injure the electrical effect, it may be removed, cleaned, and replaced without otherwise disturbing the cell; whereas if the zinc be below, it cannot be cleaned without emptying the cell and mixing the solutions, which will entail a renewal of fresh separate solutions in setting up the cell again. I have therefore planned the following form of element, which cannot but last until the zinc is eaten away so much as to fall to pieces, and which must, I think, as long as it lasts, have a very satisfactory degree of constancy. The cell is of glass, in order that the condition of the solutions and metals which it contains may be easily seen at any time. It is simply a cylindrical or rectangular jar with a flat bottom. It need not be more than 10 centimetres deep; but it may be much deeper, with ad- vantage in respect to permanence and ease of management, when very small internal resistance is not desired. A disk of thin sheet copper is laid at its bottom. A properly shaped mass of zinc is supported in the upper part of the jar. A glass tube (which for brevity will be called the charging- tube) of a centimetre or more internal diameter, ending in a wide saucer or funnel above, passes through the centre of the zinc, and is supported so as to rest with its lower open end about a centimetre above the copper. A glass siphon with cotton-wick core is placed so as to draw liquid gradu- ally from a level about a centimetre and a half above the copper. The jar is then filled with semisaturated sulphate-of-zinc solution. A copper wire or stout ribbon of copper coated with india-rubber or gutta- percha passes vertically down through the liquid to the copper-plate below, to which it is riveted or soldered to secure metallic communication. Another suitable electrode is kept in metallic communication with the zinc above. To put the cell in action, fragments of sulphate of copper, small enough to fall down through the charging-tube, are placed in the funnel above. In the course of a very short time the whole liquid below the lower end of the charging-tube becomes saturated with sulphate of copper, and the cell is ready for use. It may be kept always ready by occasionally (once a week for instance) pouring in enough of fresh water, or of water quarter saturated with sulphate of zinc at the top of the cell, 256 Sir William Thomson ona ~ [Jan. 19, to replace the liquid drawn off by the siphon from near the bottom. A cover may be advantageously added above, to prevent evaporation. When the cell is much used, so that zinc enough is dissolved, the liquid added above may be pure water; orif large internal resistance is not objected to, the liquid added may be pure water, whether the cell has been much used or not; but after any interval, during which the battery has not been much in use, the liquid added ought to be quarter saturated, or even stronger solution of sulphate of zinc, when it is desired to keep down the internal resistance. It is probable that one or more specific-gravity beads kept constantly floating between top and bottom of the heterogeneous fluid will be found a useful adjunct, to guide in judging whether to fill up with pure water or with sulphate-of-zinc solution. They may be kept in a place convenient for observation by caging them in a vertical glass tube perforated sufficiently to secure equal density in the horizontal layers of liquid, to be tested by the floaters. An extemporized cell on this plan was exhibited to the Royal Society, and its resistance (measured as an illustration of Mance’s method, de- scribed in the first of his two previous communications) was found to be °29 of an Ohm (that is to say, 290,000,000 centimetres per second). The copper and zinc plates of this cell, being circular, were about 30 cen- timetres in diameter, and the distance between them was about 7*5 centi- metres. A Grove’s cell, of such dimensions that forty in series would give ~ an excellent electric light, was also measured for resistance, and found to be ‘19 of an Ohm. Its intensity was found to be 1°8 times that of the new cell, which is the usual ratio of Grove’s to Daniell’s ; hence seventy- two of the new cells would have the intensity of forty of Grove’s. But the resistance of the seventy-two in series would be 209 Ohms, as against 76 Ohms of the forty Grove’s; hence, to get as powerful an electric light, threefold surface, or else diminished resistance by diminished distance of the plates, would be required. How much the resistance may be dimi- nished by diminishing the distance rather than increasing the surface, it is impossible to deduce from experiments hitherto made. Two or three cells, such as the one shown to the Royal Society, will be amply sufficient to drive a large ordinary turret-clock without a weight ; and the expense of maintaining them will be very small in comparison with that of winding the clock. The prime cost of the heavy wheel-work will be avoided by the introduction of a comparatively inexpensive electro- magnetic engine. For electric bells, and all telegraphic testing and signal- ing on shore, the new form of battery will probably be found easier of management, less expensive, and more trustworthy than any of the forms of battery hitherto used. For use at sea, it is probable that the sawdust Daniell’s, first introduced on board the ‘ Agamemnon’ in 1858, and ever since that time very much used both at sea and on shore, will still probably be found the most convenient form; but the new form is certainly better for all ordinary shore uses. 1871.] Constant Form of Daniell’s Battery. — 257 The accompanying drawing represents a design suitable for the electric light, or other purposes, for which an interior resistance not exceeding ;%, of an Ohm is desired. The zinc is in the form of a grating, to prevent the lodgment of bubbles of hydrogen gas, which I find constantly, but very slowly, gathering upon the zincs of the cells I have tried, although the solutions used have no free acid, unless such as may come from the ordi- nary commercial sulphate of copper and commercial sulphate-of-zinc erystals which were used. POSTSCRIPT. Received February 2, 1871. The principle which I have adopted for keeping the sulphate of copper from the zinc is to allow it no access to the zinc except by true diffusion. This principle would be violated if the whole mass of the liquid contiguous to the zinc is moved toward the zine. Such a motion actually takes place in the second form of element (that which is represented in the drawing, and which is undoubtedly the better form of the two) every time crystals of sulphate of copper are dropped inte the charging-tube. As the crystals dissolve, the liquid again sinks, but not through the whole range through which it rose when the crystals were immersed. It sinks further as the sulphate of copper is electrically precipitated on the copper plate below in course of working the battery. Neglecting the volume of the metallic copper, we may say, with little error, that the whole residual rise is that corresponding to the volume of water of crystallization of the crystals which VOL, XIX. = 258 On a Constant Form of Daniell’s Battery. [Jan. 19, have been introduced and used. It becomes, therefore, a question whether it may not become a valuable economy to use anhydrous sulphate of copper instead of the crystals; but at present we are practically confined to the ‘blue vitriol’’ crystals of commerce, and therefore the quantity of water added at the top of the cell from time to time must be, on the whole,- at least equal to the quantity of water of crystallization introduced below by the crystals. Unless a cover is added to prevent evaporation, the quantity of water added above must exceed the water of crystallization introduced below by at least enough to supply what has evaporated. There ought to be a further excess, because a downward movement of the liquid from the zinc to the level from which the siphon draws is very desirable to retard the diffusion of sulphate of copper upwards to the zinc. Lastly, this down- ward movement is also of great value to carry away the sulphate of zinc as it is generated in the use of the battery. The quantity of water added above ought to be regulated so as to keep the liquid in contact with the zinc a little less than half saturated with sulphate of zinc, as it seems, from the observations of various experimenters, that the resistance of water semisaturated with sulphate of zinc is considerably less than that of a sa- turated solution. A still more serious inconvenience than a somewhat in- creased resistance has been pointed out to me by Mr. Varley as a consequence of allowing sulphate of zinc to accumulate in the battery. Sulphate of zinc crystallizes over the lip of the jar, and forms pendents like icicles outside, which act as capillary siphons, and carry off liquid. Mr. Varley tells me that this curious phenomenon is not unfrequently observed in telegraph- batteries, and sometimes goes so far as to empty a cell and throw it alto- gether out of action. Even without this extreme result, the crystallization of zinc about the mouth of the jar is very inconvenient and deleterious. It is of course altogether avoided by the plan I now propose. In conclusion, then, the siphon-extractor must be arranged to carry off all the water of crystallization of the sulphate of copper decomposed in the use of the cell, and enough of water besides to carry away as much sulphate of zinc as is formed in the use of the battery. Probably the most conve- nient mode of working the system in practice will be to use a glass capillary siphon, drawing quickly enough to carry off in a few hours as much water as is poured in each time at the top ; and to place, as shown in the draw- ing, the discharging end of the siphon so as to limit the discharge to a level somewhat above the upper level of the zincgrating. It will no doubt be found convenient in practice to add measured amounts of sulphate of copper by the charging-tube each time, and at the same time to pour ina measured amount of water, with or without a small quantity of sulphate of zinc in solution. As 100 parts by weight of sulphate of copper crystals contain, as nearly as may be, 36 parts of water, it may probably answer very well to put in, for every kilogramme of sulphate of copper, half a kilogramme of water. Expe- rience (with the aid of specific-gravity beads) will no doubt render it very 1871.] Altitude Determination of a Ship’s Place. 259 easy, by a perfectly methodical action involving very little labour, to keep the battery in good and constant action, according to the circumstances of each case. When, as in laboratory work, or in arrangements for lecture-illustrations, there may be long intervals of time during which the battery is not used, it will be convenient to cease adding sulphate of copper when there is no immediate prospect of action being required, and to cease pouring in water when little or no colour of sulphate of copper is seen in the solution below. The battery is then in a state in which it may be left untouched for months or years. All that will be necessary to set it in action again will be to fill it up with water to replace what has evaporated in the interval, and stir the liquid in the upper part of the jar slightly, until the upper specific- gravity bead is floated to near the top by sulphate of zinc, and then to place a measured amount of sulphate of copper in the funnel at the top of the charging-tube. VI. “On the Determination of a Ship’s Place from Observations of _ Altitude.” By Sir Witi1am Tuomson. Received Feb. 6, 1871. The ingenious and excellent idea of calculating the longitude from two dif- ferent assumed latitudes with one altitude, marking off on a chart the points thus found, drawing a line through them, and concluding that the ship was somewhere on that line at the time of the observation, is due to Captain T. H. Sumner *. It is now well known to practical navigators. It is de- scribed in good books on navigation, as, for instance, Raper’s ($§ 1009- 1014). Were it not for the additional trouble of calculating a second triangle, this method ought to be universally used, instead of the ordinary practice of calculating a single position, with the most probable latitude taken as if it were the true latitude. -I believe, however, that even when in a channel, or off a coast trending north-east and south-west, or north- west and south-east, where Sumner’s method is obviously of great practical value, some navigators do not take advantage of it; although no doubt the most skilful use it habitually in all circumstances in which it is advantageous. I learned it first in 1858, from Captain Moriarty, R.N., on board H.M.S. ‘Agamemnon. Heused it regularly in the Atlantic Telegraph expeditions of that year and of 1865 and 1866, not merely at the more critical times, but in connexion with each day’s sights. Instead of solving two triangles, as di- rected by Captain Sumner, the same result may be obviously obtained by * ‘A new and accurate method of finding a Ship’s Position at Sea,’ by Capt. I. H. Sumner. Boston, 1843. ‘In 1843, Commander Sullivan, R.N., not having heard of “this work, found the line of equal altitude on entering the River Plate ; and identifying ‘the ship’s place on it in 12 fathoms by means of the chart, shaped his course up the “river. The idea may thus have suggested itself to others; but the credit of having “reduced it to a method and made it public belongs to Capt. Sumner.”’ (Raper’s Na- vigation, edition 1857.) x 2 260 Sir W. Thomson on the Determination of a ([Jan. 19, finding a second angle (Z) of the one triangle (P ZS) ordinarily solved (P being the earth’s pole, Z the ship’s zenith, and S the sun or star). The angle ordinarily calculated is P, the hour-angle. By calculating Z, the sun’s azimuth also, from the same triangle, the locus on which the ship must be is of course found by drawing on the chart, through the point which would be the ship’s place were the assumed latitude exactly correct, a line inclined to the east and west at an angle equal to Z. But, as Captain Mo- riarty pointed out to me, the calculation of the second angle would involve about as much work as solving for P a second triangle with a slightly dif- ferent latitude ; and Capt. Sumner’s own method has practical advantages in affording a check on the accuracy of the calculation by repetition with varied data. A little experience at sea suggests that it would be very desirable to dispense with the morning and evening spherical triangles altogether, and to abolish calculation as far as possible in the ordinary day’s work. When we consider the thousands of triangles daily calculated among all the ships at sea, we might be led for a moment to imagine that every one has been already solved, and that each new calculation is merely a repetition of one already made ; but this would be a prodigious error; for nothing short of accuracy to the nearest minute in the use of the data would thoroughly suffice for practical purposes. Now, there are 5400 minutes in 90°, and therefore there are 5400? or 157,464,000,000 triangles to be solved each for a single angle. This, at 1000 fresh triangles per day, would occupy above 400,000 years. Even with an artifice, such as that to be described below, for utilizing solutions of triangles with their sides integral numbers of de- grees, the number to be solved (being 90° or 729,000) would be too great, and the tabulation of the solutions would be too complicated (on account of the trouble of entering for the three sides) to be convenient for prac- tice; and Tables of this kind which have been actually calculated and published (as, for instance, Lynn’s Horary Tables *) have not come into ge- neral use. It has occurred to me, however, that by dividing the P problem into the solution of two right-angled triangles, it may be practically worked out so as to give the ship’s place as accurately as it can be deduced from the ob- servations, without any calculation at all, by aid of a table of the solution of the 8100 right-angled spherical triangles Z of which the legs are integral numbers of degrees. Let O be the point in which the arc of a great circle , less than 90° through S, perpendicular to P Z, meets P Z or P Z produced. If the data were S P, P Z, and the hour-angle P, the solution of the right-angled triangle SPO would give PO and SO. Subtracting PZ * Horary Tables for finding the time by inspection &c., by Thomas Lynn, late Com- mander in the sea-service of the Hast-India Company. 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ZB | FL GSE | GF 18 | EL 9E €1 18 |6 8& re @3 | 9% ze || 6L 28 | cs ge || P G8 | FS FE || Gh GB | GS GE || CE ZB | IG OE 0 & | SI 8& ZL #8 | @ ze || 6G eg | BE ee || SF ES | OF FE || TE 8 | 6e GE | LE €8 | 8G YE LP GS | 93 SE | 6 0¢ $8 | 8@ ze | ge FQ | Ze Ge || 96 F8 | Ze Fe | FI HS | 9E SE T FS] GE OF re €8 | Ge 8E | 8 6% 98 | &F ze || 81 eg | ze ge || 2 G8 | SF ve | 9¢ F8 | lh GE | Gh P8 | IP OE GB FS | GE BE | Z 4 98 | 8P ze || se eg | Ze Ge || GF G8 | Lh Fe || GE 8 | OF GE || OF G8 | OF 9E OL &8 | Sk se | 9 9F 98 | Zo ze || 82 98 | 1¢ Se || 08 98 | 1S FE || GS 98 | OG GE || ST 98 | OF YE g¢ G8 | 6F 8e | § ro 28 | Gc se || 8ST £8 | FG ef || SI £8 | PS FE || 9 48] FE SE || 6g 98 | FE 9E oF 98 | &¢ SE | F e 98/| se ze |l 6c £8 | £¢ ee || FS £8 | LE FE || GF £8 | Lo GE || PH L8 | OG 9E rE £8 | 9E BE Ze 88 | GE se || Ge 88 | 6S ee || 9E 88 | GE FE || EF 88 | 6S GE | OF 88 | 8G OE @Z 88 | 8g 8E | & 1% 68/9 £2 || 03 68 | 0 Fe | $1 68/9 SE] 91 G8) O ge] Al es) Ze It 68) 9 ge) ft ‘Vv ddqy-00 Vv ‘d£y-00 Vv ‘dy-00 ‘Vv dAy-00 Vv dAy-00 V ‘dAy-09 9 “Lg —=9 "9G=0 "Gg=0 (pe=v “ofS =P rola =a 1871.] Ship’s Place from Observations of Altitude. 261 from PO, we have ZO; and this, with S O in the triangle S ZO, gives the zenith distance, S Z, and the azimuth, S ZO, of the body observed. Suppose, now, that the solution of the right-angled spherical triangle S PO for PO and S O to the nearest integral numbers of degrees could suffice. Further, suppose P Z to be the integral number of degrees closest to the estimated co-latitude, then ZO will be also an integral number of degrees. Thus the two right-angled spherical triangles SPO and SZO have each arcs of integral numbers of degrees for legs. Now I find that. the two steps which I have just indicated can be so managed as to give, with all attainable accuracy, the whole information deducible from them~ regarding the ship’s place. Thus the necessity for calculating the solutions of spherical triangles in the ordinary day’s work at sea is altogether done away with, provided a convenient Table of the solutions of the 8100 triangles is available. I have accordingly, with the cooperation of Mr. E. Roberts, of the ‘ Nautical Almanac’ Office, put the calculation in hand; and I hope soon to be able to publish a Table of solutions of right-angled spherical triangles, showing co-hypotenuse* and one angle, to the nearest minute, for every pair of values of the legs from 0° to 90°. The rule to be pre- sently given for using the Tables will be readily understood when it is con- sidered that the data for the two triangles are their co-hypotenuses, the difference between a leg of one and a leg of the other, and the condition that the other leg is common to the two triangles. The Table is arranged with all the 90 values for one leg (4) in a vertical column, at the head of which is written the value of the other leg (a). Although this value is really not wanted for the particular nautical problem in question, there are other applications of the Table for which it may be useful. On the same level with the value of 4, in the column corresponding to a, the Table shows the value of the co-hypotenuse and of the angle A opposite to the leg a. I take first the case in which latitude and declination are of the same name, the latitude is greater than the declination, and the azimuth (reckoned from south or north, according as the sun crosses the meridian to the south or north of the zenith of the ship’s place) is less than 90°. The hypotenuses, legs, and angles P and Z of the two right-angled triangles of the preceding diagram are each of them positive and less than 90°, and the two co-hypo-. tenuses are the sun’s declination and altitude respectively. We have then the following rule :— (1) Estimate the latitude to the nearest integral number of degrees by dead reckoning. (2) Look from one vertical column to another, until one is found in which co-hypotenuses approximately agreeing with the declination and altitude are found opposite to values of 6 which differ by the complement of the assumed latitude. (3) The exact values of the co-hypotenuse and the angle A corresponding * It is more convenient that the complements of the hypotenuses should be shown than the hypotenuses, as the trouble of taking the complements of the declination and the observed altitude is so saved. i ees loa = eee ae oes Sie i | co-hyp. : yp- |co-hyp.| A. |ico-hyp.) A. jeo-hyp.| A. || co-hyp. | A. ||co-hyp.| A. Cenawvs woo asec —b ots ete : Aa ea a ee ee I dr ie commence ° ‘ ° ‘ ° ‘ al 5 : § 6 36 6| 8916) 35 6| 8918 | af 6| 89.20) 33 6 | shat | 33 6) 8h 98 37 58 35 59 | 88 33 | 34 59 | 88 36 | 33 59 | 88 39 || 32 59 | 88 42 | 31 59 | S88 37 56 35 57 | 87 49 || 34 57 | 87 54 | 33 57 | 87 59 || 32 57 | 88 3 | 31 57 | 88 37 53 35 54 | 87 6 || 34 54 | 87 12 | 33 54 | 87 18 | 32 55 | 87 24 | 31 55 | 87 30 7 50 35 50 | 86 23 || 34 51 | 86 30 | 33 51 | 86 38 || 32 52 | 86 46 | 31 52 | 86 37 45 35 46 | 85 39 || 34 47 | 85 49 | 33 47 | 85 58 || 32 48 | 86 7 | 81 48 | 86 37 40 35 41 | 84 56 | 34 42 | 85 7 | 33 42 | 85 18 || 32 43 | 85 29 || 31 44 | 85 35 36 | $4 14 | 34 37 | 84 26 | 33 37 | 84 38 || 32 38 | S4 50 | 31 39 | 85 35 29 | 83 31 || 34 30 | 83 45 | 33 32 | 83 59 | 32 33 | 84 12 | 31 34) SH: 35 22 | 82 49 || 34 24] 83 4 || 33 25 | 83 19 || 32 26 | 83 34 || 31 27 | 88 35 14 | 82 6 || 34 16 | 82 28 || 33 18 | 82 40 || 32 19 | 82 56 | 31 21 | 83 35 61} 8125 || 34 8 | 81 43 || 38 10| 82 1 || 82 11 | 82 19 || 31 13 | 82 ¢ 34 56 | 80 43 || 33 59 | 81 3 || 38 1] 81 22 | 82 3 | 81 41 | 81 5 | 82 34 46 | 80 2 || 33 49 | SO 23 | 32 52 | 80 44 | 31 54 | 81 4 | 3057/81 2 34 36 | 79 21 || 33 39 | 79 44 32 42 | 80 6 || 31 44 | 80 28 | 30 47 | SO 34 24 | 78 41 || 33 28 | 79 5 || 32 31 | 79 28 || 31 34 | 79 51 || 30 37 | 80 3412 | 78 0 || 83 16 | 78 26 | 32 20 | 78 51 || 31 23 | 79 15 | 80 27 | 79 & 33 59 | 77 21 || 8338 4 | 77 47 || 32 8 | 78 14 || 81 12 | 78 39 || 30 16 | 79 i ‘ 55 | 77 87 || 31 0 | 33 32 | 76 3 || 32 37 | 76 32 || 31 42 | 77 1 || 80 47 | 77 29 || 29 52 | 77 33.17 | 75 24 || 82 23 | 75 5d | 31 28 | 76 25 | 80 34 | 76 54 | 29 39 | 77 i | 74 46 | 32 8 | 75 18 | 81 14) 75 49 |) 80 20 | 76 20 | 29 20 | 76 245 | 74 9 || 31 52 | 74 42 | 30 59 | 75 14 | 30 5 | 75 46 | 29 12 | 76 32 29 | 74 82 || 31 36 | 74 6 || 80 43 74 40 || 29 50 | 75 12 || 28 57 | 75 32 11 | 72 56 || 31 19 | 73 81 || 380 27 | 74 5 || 29 35 | 74 39 |) 28 42 | 75 os = = o ~_ oc te <) =) to tw Cc os tw > So be") nw oO hob wc ors cme OONNIS o> i) SS an _ = 3S SY SSe nw — 7 ~“ ce oc ~~ = _ be a to _ - to I — to ce te “ _ ior) “I i) = S ce be 7 1 corns - S o cs “I a nm cr te ou w © = Ge n te or cs eG tw we bo bo " —) co oa co a te uo =: cs i=r) oc SS So or rae ao - = rw oa = ~ a = co - i _ oe _ a a — ss — ao a ir) a co o ns — tw _ a _- 19 11 | 68 56 || 18 42 | 59 52 || 18 13 | 60 47 || 17 44 | 61 42 || 17 14 | 62 18 40 | 58 39 || 18 12 | 59 35 || 17 44 | 60 80 | 17 15 | 61 26 || 16 46 | 62 18 9 | 58 22 || 17 42 | 59 18 || 17 14 | 60 14 || 16 46 | 61 9 | 16 19} 62 17.37/58 5 || 17 11| 59 2) 16 44 | 59 58 | 16 17 | 60 54 | 15 50 | 61 17. 5 | 57 49 || 16 40 | 58 46 || 16 14 | 59 43 | 15 48 | 60 39 || 15 22 | 61 16 33 | 57 84 || 16 9 | 58 31 || 15 44 | 59 28 || 15 19 | GO 24 |) 14 58 | GL 16 1157 19 || 15 87 | 58 16 || 15 13 | 59 13 | 14 49 | GO 10 | 14 24 | 61 15 29|57 5] 15 6] 58 2] 1442/59 0 | 14 19 | 59 57 || 13 55 | 60 54 14 56 | 56 51 || 14 34 | 57 49 || 14 11 | 58 46 | 13 49 | 59 44 | 13 26 60 41 14 23 | 56 88 || 14 2 | 57 36 | 13 40 | 58 34 | 18 18) 59 31 |) 12 56 60 29 13 50 | 56 26 || 13 29 | 57 24 || 18 9] 58 22 || 12 48 | 59 19 || 12 27 | 60 17 13 17 | 56 14 | 12 57 | 57 12 | 12 87 | 58 10 | 12 17 | 59 8 | 11 57 | 60 8 243/56 2 || 1224157 0] 12 6} 57 59 || 11 46 | 58 57 || 11 27 | 59 55 53 ¢ 210/55 51 |] 11 52 | 56 50 || 11 34 | 57 48 || 11 15 | 58 46 || 10 57 59 45 5 1 36 | 55 41 |} 11 19 | 56 39 || 11 2} 57 38 || 19 44 | 58 36 || 10 27 | 59 35 53 1 2| 55 31 || 10 46 | 56 30 || 10 29 | 57 28 | 10 13 | 58 27 || 9 56 | 59 25 58 | 53 : 0 28 | 55 21 || 10 13 | 56 20 |) 9 57 | 57 19 || 9 41 | 5818) 9 25 | 59 17 22 | 5 9 54] 55 13|| 9 39'| 56 12]| 925/57 11 || 9 10] 58 9 || 8 55 59 8 9 3 ar 5 i 919|55 4] 9 6) 56 3|) 852) 57 2) 8 38 | 58 2]| 8 24 59 1 910] 5258 ]| $58|53 57 | 845] 5456 | 8 32] 55 56 || 8 19 56 55 || 8 6 | 57 54 7 53 58 53 8 34] 5250 || 8 22) 5350] 811 | 5449 || 759/55 48) 7 46 | 56 48 || 7 34 | 57 47 | 7 22 | 58 46 7 58 | 52.43) 7 47 | 53 43 |) 7 36 | 54 42 |) 7 25 | 55 42) 7 14 | 56 41) 7 2) 57 41 || 6 51 | 58 40 721 | 5237 || 711/53 36] 7 1| 5436 |} 6 51 | 55 36 || 6 41 | 56 35 || 6 30) 57 35 || 6 20 | 58 34 6 45 | 5231 | 636) 53 31 || 6 26| 53 80] 617| 55 30] 6 8| 5629) 5 58) 57 29) 5 48 | 58 29 6 85226) 6 0|5325|| 5515423) 543] 55 95) 5 34| 5624 | 5 26/57 24|| 5 17 | 58 24 5 32 | 52 21 | 5 a4]53 20) 5317] 5420 1 5 9155 20 || 5 1} 56 20 || 453) 57 19 || 4 45 | 58 19 455/52 16) 448] 5316 || 442] 5416) 435) 55 16) 428) 5616 || 4 21 57 15 | 414 | 58 15 418]/5212]) 419/53 12] 4 6|5412 | 4 0/5512 | 355 | 5612) 348) 57 12)) 3 42 | 58 12 341]/52 91 336|53 9] 331]/54 9] 326)55 9) 321/56 9) 316)57 9) 311 58 9 3 5/52 6] 3 0153 6] 956/54 6) 2959|55 6 | 248) 56 6] 243) 57 6 || 239/58 6} 8 298]/52 4]| 994/53 4] 921/54 4] 218/55 4] 214/56 4)) 211) 57 4 2: 7 pes) Sees 151|52 2]} 148/53 2] 146/54 2] 143/55 2] 141/56 2] 138)57 2) 1 45 ae dl 114152 1] Vis]58 1) 212)54 1} 1 9) 55 TH 1 7) 56 1 1 Bor 1) 6 ee 037/52 0] 036/53 0! 035/54 0] 034/55 0] 034/)56 0} 033) 57 0} 032 ne S| od 0} 52 0 0 0;53 OF O 0} 54 O 00,55 O 0 0/56 0} 0 0/57 0 0 0;}5 | | | / : ; : } j | CHIT Crm Coho mo 1871. | Ship’s Place from Observations of Altitude. 261 from PO, we have ZO; and this, with S O in the triangle S ZO, gives the zenith distance, S Z, and the azimuth, S ZO, of the body observed. Suppose, now, that the solution of the right-angled spherical triangle S PO for PO and S O to the nearest integral numbers of degrees could suffice. Further, suppose P Z to be the integral number of degrees closest to the estimated co-latitude, then ZO will be also an integral number of degrees. Thus the two right-angled spherical triangles SPO and SZO have each arcs of integral numbers of degrees for legs. Now I find that. the two steps which I have just indicated can be so managed as to give, with all attainable accuracy, the whole information deducible from them- regarding the ship’s place. Thus the necessity for calculating the solutions of spherical triangles in the ordinary day’s work at sea is altogether done away with, provided a convenient Table of the solutions of the 8100 triangles is available. I have accordingly, with the cooperation of Mr. E. Roberts, of the ‘ Nautical Almanac’ Office, put the calculation in hand; and I hope soon to be able to publish a Table of solutions of right-angled spherical triangles, showing co-hypotenuse* and one angle, to the nearest minute, for every pair of values of the legs from 0° to 90°. The rule to be pre- sently given for using the Tables will be readily understood when it is con- sidered that the data for the two triangles are their co-hypotenuses, the difference between a leg of one and a leg of the other, and the condition that the other leg is common to the two triangles. The Table is arranged with all the 90 values for one leg (4) in a vertical column, at the head of which is written the value of the other leg (a). Although this value is really not wanted for the particular nautical problem in question, there are other applications of the Table for which it may be useful. On the same level with the value of 4, in the column corresponding to a, the Table shows the value of the co-hypotenuse and of the angle A opposite to the leg a. I take first the case in which latitude and declination are of the same name, the latitude is greater than the declination, and the azimuth (reckoned from south or north, according as the sun crosses the meridian to the south or north of the zenith of the ship’s place) is less than 90°. The hypotenuses, legs, and angles P and Z of the two right-angled triangles of the preceding diagram are each of them positive and less than 90°, and the two co-hypo- tenuses are the sun’s declination and altitude respectively. We have then the following rule :— (1) Estimate the latitude to the nearest integral number of degrees by dead reckoning. (2) Look from one vertical column to another, until one is found in which co-hypotenuses approximately agreeing with the declination and altitude are found opposite to values of 6 which differ by the complement of the assumed latitude. (3) The exact values of the co-hypotenuse and the angle A corresponding * It is more convenient that the complements of the hypotenuses should be shown than the hypotenuses, as the trouble of taking the complements of the declination and the observed altitude is so saved. . 262 Sir W, Thomson on the Determination of a [Jan. 19, to these values of 4 are to be taken as approximate declination, hour-angle, altitude, and azimuth. (4) Either in the same or in a contiguous vertical column find similarly another set of four approximate values, the two sets being such that one of the declinations is a little less and the other a little greater than the true declination. (5) On the assumed parallel of latitude mark off the points for which the actual hour-angles at the time of observation were exactly equal to the approximate hour-angles thus taken from the Table. With these points as centres, and with radii equal (miles for minutes) to the differences of the approximate altitude from the observed altitude, describe circles. By aid of a parallel ruler and protractor *, draw tangents to these circles, inclined to the parallel of latitude, at angles equal to the approximate azimuths taken from the Table. These angles, if taken on the side of the parallel away from the sun, must be measured from the easterly direction, or the westerly direction, according as the observation was made before or afternoon. The tangent must be taken on the side of the circle towards the sun, or from the sun, according as the observed altitude was greater or less than the ap- proximate altitude taken from the Tables in each case. The two tangents thus drawn will be found very nearly parallel. Draw a line dividing the space between them into parts proportional to the differences of the true declination, from the two approximate values taken from the Tables. The ship’s place at the time of the observation was somewhere on the line thus found. To facilitate the execution of clause (2) of the rule, a narrow slip of card should be prepared with numbers 0 to 90 printed or written upon it at equal intervals, in a vertical column, equal to the intervals in the vertical column of the Table, 0 being at the top and 90 at the bottom of the column as inthe Table. Place number 90 of the card abreast of a value of co-hy- potenuse in the Table approximately equal to the declination, and look for the other co-hypotenuse abreast of the number on the card equal to the assumed latitude. Shift the card from column to column according to this condition until the co-hypotenuse abreast of the number on the card ‘ equal to the assumed latitude is found to agree approximately enough | with the observed altitude. ; When the declination and latitude are of contrary names and the azimuth less than 90°, or when they are of the same names, but the declination greater than the latitude, the sum, instead of the difference, of the legs } of the two triangles will be equal to the complement of the assumed latitude; and clause (2) of the rule must be altered accordingly. The slip of card in this case cannot be used; but the following scarcely less easy process is to be practised. Put one point of a pair of compasses on a position in one of the vertical columns of the hypotenuse abreast of * A circle divided to degrees, and having its centre at the centre of the chart, ought to be printed on every chart. This, rendering in all cases the use of a separate pro- tractor unnecessary, would be usgful for many purposes. 1871.] Ship’s Place from Observations of Altitude. 263 that point of the column of values of & corresponding to half the comple- ment of the assumed latitude; this point will be on a level with one of the numbers, or midway between that of two consecutive numbers, accord- ing as the assumed latitude is even or odd: then use the compasses to indicate pairs of co-hypotenuses equidistant in the vertical column from the fixed point of the compasses, and try from one column to another until co-hypotenuses approximately agreeing with the observed altitude and the correct declination are found. It is easy to modify the rule so as to suit cases in which the azimuth is an obtuse angle; but it is not worth while to do so at present, as such cases are rarely used in practice. The following examples will sufficiently illustrate the method of using the Tables :— (1) On 1870, May 16, afternoon, at 5h. 42m. Greenwich apparent time, the Sun’s altitude was observed to be 32° 4!: to find the ship’s place, the assumed latitude being 54° North. The Nautical Almanac gives at 1870, May 16, 5h. 42m. Greenwich apparent time, the Sun’s apparent declination N. 19° 10’. On looking at the annexed Table (which is a portion of the solutions of the 8100 right-angled spherical triangles) under the heading a = 56°, and opposite 6 = 54°, the co-hypotenuse (representing the Sun’s declination) is 19° 11’, and opposite 6 = 18° (differing from 54° by the complement of the assumed latitude), the co-hypotenuse (representing the Sun’s altitude) is 32° 8', which are sufficiently near the actual values; we therefore select our sets of values from these columns as follows :— Co-hyp. A. -1. b=54 1911 61 28=Sun's hour-angle. | 6=18 32 8 78 14=Sun’s azimuth (S. towards W.). = 56° [2 6=55 18 42 61 5=Sun’s hour-angle. b=19 dL 55 77 37 =Sun’s azimuth (S. towards W.). from which we have the following :— Greenwich apparent time (in arc) CTE saeeaeea 85 30 Sun’s hour-angle (8 SI RS eee eee (2) 61 5 Diff. = Longitude 24 7 W. 24 25 W. Sun’s altitude (observed) So cee ee 32 4 Sun’s altitudes (auxiliary) (Ee o2. & ee, (2) 38155 Sun’s declination from N. A. TRO ee 2°42) 19 16 Sun’s declinations (auxiliary) (1) 1911 ............ (2) 18 42 Dif= — 28 264 Sir W. Thomson on the Determinatian of a [Jan. 19, This example is represented graphically in the first diagram annexed. The second set of values could have been selected equally well from the contiguous columns (a=57°), which on trial will be found to give an almost identical result. Again, (2), on 1870, May 16, afternoon, at 5h. 42m. Greenwich ap- parent time, the Sun’s altitude was observed to be 30° 30': to find the ship’s place, the assumed latitude being 10° North. The Sun’s declination from N. A. is N. 19° 10!, and the half comple- ment of the assumed latitude 40°. By a few successive trials, a=56° will be found to contain values of co-hypotenuses approximately equal to the Sun’s declination and altitude at the time, and which are equidistant from 40°; we therefore select the following sets of values from this column as follows :— : Co-hyp. A. (1. b=a4 19 11 61 23=Sun’s hour-angle. | b=26 30 10 73 32=Sun’s azimuth (N. towards W.). ae 18 42 61 5=Sun’s hour-angle. \ 627 29 53 72 58 =S8un’s azimuth (N. towards W.). from which we have the following :— Greenwich apparent time (in arc) 65.30: a2 85 30 Sun's hour-angle (Cl) 5 Gl i23).2s eat (2) 61 5 Diff. = Longitude 24 7 W. 24 25 W. Sun’s altitude (observed) 30.80 ae see 30 30 Sun’s altitudes (auxiliary) (1) S010 eee (2) 29 53 Diff = + 20 + 37 Sun’s declination from N. A. 19: 10-23 eee 19 16 Sun’s declinations (auxiliary) (1) 1911............ (2) 1842 DT, =) 1 + 28 In this,case the sun passes the meridian to the north of the ship’s zenith, the azimuth, from the Tables being less than 90°, is measured from the north towards the west. -In this case also the second set of values might have been taken from a=57°, which will be found on trial to give a position nearly identical with the above. This example is represented in the second diagram annexed. Again, (3), on 1870, May 16, afternoon, at 5h. 42m. Greenwich ap- parent time, the Sun’s altitude was observed to be 18° 35': to find the ship’s place, the assumed latitude being 20° South. The Sun’s declination from N. A. is N. 19°-10!', and the half complement of the assumed latitude is 55°, to be used because the Sun’s declination and the assumed latitude are of different names. Proceeding as in the previous ee ee es oe SS = “~~ a) ss NX > f = Ss s Ss rc) rig D H- SS (5) S = a, DD © ss au x) 3 DW 1871.] 266 Prof. Story Maskelyne on the” — [Jan. 26, example, we find the column @=56° again to contain values of co-hypo- tenuses approximately equal to the given values; and therefore have :— Co-hyp. A. (lOO: 19 1 61 23=Sun's hour-angle. | b=56 18 13 60 47 =Sun’s azimuth (N. towards W.). a=56° 4 |2. b=55 18 42 61 5=S8un’s hour-angle. \ b=57 1744 60 380=Sun’s azimuth (N. towards W.). which give Greenwich apparent time (in arc) yee wren a 85 30 Sun’s hour-angle CU) Ob 2oRenkea es (2) 61 5 Diff. = Longitude 24 7 W. 24 25 W. Sun’s altitude (observed) 1S 30) ota ine 18 35 Sun’s altitudes (auxiliary) GO Meee rok li pene pane (2) 1744 Diff. = + 22 + 51 Sun’s declination from N. A. 1910 ees 19 10 Sun’s declinations (auxiliary) (1) 1911............ (2) 1842 iS + 28 This example is represented in the third diagram annexed.. January 26, 1871. General Sir EDWARD SABINHE, K.C.B., President, in the Chair. The following communications were read :— I. “On the Mineral Constituents of Meteorites.” By Nreviu Story _ Masxetyne, M.A., F.R.S., Professor of Mineralogy, Oxford, and Keeper of the Mineral Department, British Museum. Re- ceived November 3, 1870. (Abstract. ) In the memoir now offered to the Society the author gives the results of his investigation of the meteorites of Breitenbach and of Shalka. A preliminary notice of two of the minerals occurring in the former, which is of the Siderolite class, was read before the Society in March, 1869 (Proc. R. 8S. vol. xvii. p. 370). After entering upon the probable history of the Breitenbach Siderolite, and endeavouring to identify it with certain other Siderolites that have been found, or have been recorded as found, in the region extending from 1871.] Mineral Constituents of Meteorites. 267 Meissen to Breitenbach, the author proceeds to describe the individual’ minerals which constitute the mass of the Siderolite. These are: first, a bronzite with the formula (Mgs Fe: ) Si O3, or- thorhombic in its crystalline form. The crystallography of the mineral was investigated by Dr. Viktor von Lang at the British Museum, and has been published in Pogg. Annalen, vol. cxxxix. p. 315. Secondly, a mineral composed of silica, having the specific gravity of quartz after fusion, and crystallized in the orthorhombic system. Since his preliminary notice was published, the crystallography of this substance has been carefully studied by the author, and the details are given in the memoir. The elements of the crystal are Gee Gis lf 457 2) le ool 20: The angles are :— 100:101 = 27°46' 100:110 = 60°10’ 110:101 = 63°19’ The optic axes lie in a plane parallel to the plane 010 ; the first mean line being the normal to the plane 100. They are widely separated, presenting in air an apparent angle of about 107°. There can thus be no question that this mineral is orthorhombic ; and if the tridymite of Vom Rath is, as that distinguished crystallographer asserts it to be, hexagonal in its symmetry, the mineral in the Breitenbach meteorite will be a trimorphic form of silica. Such a result obtained from the investigation of a meteorite is one of no small interest. The nickeliferous iron, the chief constituent of the Siderolite, proved on analysis to be an alloy of the formula Fe,, Ni, and contaimed a trace of copper. In addition to the two siliceous minerals, the iron encloses occasional crystals of chromite in well-developed octahedra, an iron sulphide, probably troilite, and a small amount of Schreibersite. The author then proceeds to detail the results obtained from the analysis of the Shalka meteorite. In 1860, Haidinger, in his paper on this meteorite (Sitzber. d. k. Akad. Wiss. Wien, vol. xli. p. 251), held the entire stone to be made up of a mineral, which he termed Piddingtonite, and which, according to Von Hawr’s analysis, might be a compound of bisili- cate and trisilicate of iron and magnesium. This latter acid silicate, however, which has long haunted the mineralogy of meteorites, no more forms a constituent of this meteorite than does the other acid silicate Shepardite, as Dr. Laurence Smith has shown, enter into the composition of the Bishopville meteorite. The view held by Haidinger, that this meteorite, though apparently made up of two silicates, a grey and a mottled variety, was nevertheless * the British Museum. 268 Prof. Williamson on the Organization of the [Jan. 26, composed of a single mineral species varying in colour, is proved by the analytical results given in this memoir. It has been found to bea bronzite of the formula (Mg, Fe) Si O;, and in association with it there occurs some chromite in distinct crystals. Rammelsberg has also recently published the results of an examination of this meteorite (Pogg. Annalen, vol. cxlii. p. 275), and finds in it a bronzite associated with 12 per cent. of olivine. It is probable that the meteorite varies in its composition in different parts, and that Prof. Ram- melsberg analyzed that portion where an olivinous ingredient was in ap- preciable preponderance. The mottled kind was treated with hydrogen chloride in the cold, and subsequently with potash, and again with hydrogen sulphate and potash, but in each case it was noticed that the action of the acid was confined to that of a solvent. A little meteoric iron was dissolved, but no appreciable amount of olivine was found in the portion examined in the Laboratory at II. “On the Organization of the Calamites of the Coal-measures.” By W. C. Wiuiamson, F.R.S., Professor of Natural History in Owens College, Manchester. Received November 11, 1870. (Abstract.) Ever since M. Brongniart established his genus Calamodendron, there has prevailed widely a belief that two classes of objects had previously been included under the name of Calamites—the one a thin-walled Equise- taceous plant, the Calamites proper, and the other a hard-wooded Gymno- spermous Exogen, known as Calamodendron. This distinction the author rejects as having no existence, the thick- and thin-walled examples having precisely the same typical structure. This consists of a central pith, sur- rounded by a woody zone, containing a circle of woody wedges, and enclosed within a bark of cellular parenchyma. The Pith has been solid in the first instance, but very soon became fistular, except at the nodes, at each one of which a thin diaphragm of parenchyma extended right across the medullary cavity. Eventually the pith underwent a complete absorption, thus enlarging the fistular interior until it became coextensive with the inner surface of the ligneous zone. The Woody Zone——This commenced in very young states by the formation of a circle of canals stretching longitudinally from one node to the adjoining one. Externally to, but in contact with, these canals a few barred or reticulated vessels were found ; successive additions to these were made in lines radiating from within outwards ; hence each wedge consisted — of a series of radiating laminze, separated by medullary rays, having a peculiar mural structure. At their commencement these wedges were separated by wide cellular areas, running continuously from node to node ; 1871.] _ Calamites of the Coal-measures. 269 as the woody tissues increased exogenously, these cellular tracts also ex- tended outwards. Radial longitudinal sections exhibited in these the same mural tissue that occurs in the woody wedges. Hence the author gives to the former the name of primary medullary rays, and to the latter that of secondary ones. The structure of the medullary and ligneous zones is compared with that of the stem of a true Exogen of the first year, of which transitional form Calamites may be regarded as a permanent representative. Tangential sections of this woody zone exhibit parallel bands of alternating vascular and cellular tissue, running from node to node. At the latter points each vascular band dichotomizes, its divergent halves meeting cor- responding ones from contiguous wedges, and each two unite to form one of the corresponding bands or wedges of the next adjoining internode. The Bark, hitherto undescribed, consists of a thick layer of cellular parenchyma, undivided into separate laminee, and not exhibiting any special differentiation of parts. This structure exhibits no signs of external ridges or furrows, being apparently smooth. The stem was enlarged at each node, but the swelling was less due to any increased thickness of the bark at these points, than to an expansion of the woody layer at these points, both ex- ternally and internally. This was the result of the intercalation of nume- rous short vessels, which arched across each node, their concavities being directed inwards, and which constituted the portion of the woody zone that encroached upon the constricted pith at these nodes. Several modi- fications of the above type have been met with, most of which may have had a specific value. In one form no canals exist at the inner angles of the woody wedges; in another, lamine, like those of the woody wedges, are developed in the more external portions of the primary me- dullary rays, those occupying the centre of each ray being the most ex- ternal and latest formed. The primary ray is thus transformed into a series of secondary ones. In another type the vascular laminze of each woody wedge are few in number, and the component vessels are the same; but the latter are re- markable for their large size. In a fourth variety, the exterior of the woody zone has been almost smooth, instead of exhibiting the usual ridges and furrows: this variety is also remarkable for the large size of its me- dullary cells, compared with that of the cells and vessels of the woody zone. : But the most curious modification is seen ina plant previously described by the author under the name of Calamopitus, in which round or oblong canals are given off from the medullary cavity, and pass horizontally through each primary medullary ray of the woody zone to the bark. These, being arranged in regular verticils below each node, are designated the infranodal canals. The verticils of small round or oblong scars, seen at one extremity of the internodes of some Calamites, are the results of this peculiar organization. In one species of this Calamopitus, instead of the longitudinal canals of the woody wedges terminating at the nodes, they 270 On the Calamites of the Coal-measures. [Jan. 26, bifurcate, like the wedges with which they are associated, and are con- tinuously prolonged from internode to internode. The ordinary structureless fossils found in shales and sandstones receive a definite interpretation from the specimens described. The fistular me- dullary cavities due in the first instance, not to decay of the tissues, but to the rapid growth of the stem, became further enlarged by the entire absorp- tion of the true pith, which commenced after the latter had fulfilled its purpose in the origination of the woody wedges. This process ter- minated at an undulating line of arrested absorption, the convexities of which projected outwards, opposite the primary medullary rays, and in- wards, opposite the woody wedges ; and the inorganic cast of the cavity thus formed by a physiological action constitutes the Calamites commonly seen in collections. Hence they are not, like the Sternbergiz, casts of a cavity within a true pith, but their form represents that of the exterior of the medullary tissue. The ridges and furrows of these internal casts are not identical in position with the similar undulations of the exterior of the woody zone, but alternate with them; so that the ligneous cylinder pro- jects both externally and internally where the woody wedges are located, and contracts, in like manner, at the intermediate points opposite to the primary medullary rays. The thin carbonaceous film which frequently invests these casts is the residue of the altered elements of the woody zone, and possibly also of the bark, which latter has been very liable to become detached from the former. The surface-markings of this carbo- naceous film have usually no structural significance, being merely occasioned by the impression of the hardened casts which they invest. Two kinds of branches are given off by Calamites,—the one subterranean, springing from peculiarly formed rhizomes, and the other aérial, attached to the upright unbranched stems. The former of these are of compara- tively large size, the nodes from which they have been detached being marked by large concave lenticular scars as phragmata. These branches appear to have been given off from central rhizomes in accordance with a regular phyllotaxis, but which varied in different species. The aérial branches, on the other hand, were merely slender appendages to a virtually unbranched stem; they were arranged in verticils round the nodes, in variable numbers. Each branch sprang from the interior of one of the woody wedges, the two halves of which were forced asunder to admit the base of the appendage, and from which its constituent vessels were derived. The branch, deprived of its bark, never appears to have had a diameter equal that of two of the woody wedges, and the rarity of their occurrence attached to the stem seems to indicate that they were deciduous. The bark investing them is not yet known, and the exact nature of the foliage which they bore is also uncertain, owing to discordant testimony respecting it; but there appears no reason for doubting that some of the verticillate Asterophyllites or Annulariz represent it, though there is uncertainty respecting the actual forms to be identified with Calamites. The roots 1871.] Sir W. Thomson on Approach caused by Vibration. 271 were given off from the lower part of each internode, but above the node, and were apparently epidermal. There is also considerable doubt respecting the fructification of Calamites. Some of the Volkmanniz have evidently belonged to this group ; but only one example retaining its minute organization has yet been found in which the structure of the central axes corresponded with that of the Calamites. The relationship to Calamites of the fruits figured by Binney, under the name of Calamodendron commune, which are identical wth the Volkmannia Binneyi of Carruthers, is more than doubtful, because of the anomalous structure of their central axes. After a careful comparison of the organization of Calamites with that of the recent Equisetacee, the author prefers constituting the former an independent order, distinct from, though allied to, the Equisetums, under the name of Calamitacee, and characterized by cryptogamic fructifi- cation and verticillate foliage, associated with an exogenous axis. The latter feature probably involved the existence of something resembling a cambium layer, furnishing the material for the new tissues. It is further proposed to divide these plants into two generic groups, viz. Calamites and Calamopitus; the former to comprehend those un- provided with infranodal canals, and the latter those which possess them. The existing specific distinctions appear to have little or no scientific value. III. “On Approach caused by Vibration.” A Letter from Prof. Sir W. Tuomson, LL.D., F.R.S., &c. to Prof. Freperick Guturin, - B.A. Communicated by Sir W. Tuomson. Received November 7 LO70. Dear Sir,—I have to-day received the ‘ Proceedings of the Royal Society’ containing your paper ‘‘ On Approach caused by Vibration,’ which I have read with great interest. The experiments you describe constitute very beautiful illustrations of the established theorem for fluid pressure in abstract hydro-kinetics, with which I have been much occupied in mathe- matical investigations connected with vortex-motion. According to this theorem, the average pressure at any point of an in- compressible frictionless fluid originally at rest, but set in motion and kept in motion by solids moving to and fro, or whirling round in any manner, through a finite space of it, is equal to a constant diminished by the product of the density into half the square of the velocity. This im- mediately explains the attractions demonstrated in your experiments ; for in each case the average of square of velocity is greater on the side of the card nearest the tuning-fork than on the remote side. Hence obviously the card must be attracted by the fork as you have found it to be; but it is not so easy at first sight to perceive that the average of the square of the velocity must be greater on the surfaces of the tuning-fork next to the 272 Sir W. Thomson on Approach caused by Vibration. { Jan. 26, card than on the remote portions of the vibrating surface. Your theoreti- cal observation, however, that the attraction must be mutual, is beyond doubt valid, as we may convince ourselves by imagining the stand which bears the tuning-fork and the card to be perfectly free to move through the fluid. If the card were attracted towards the tuning-fork, and there were not an equal and opposite force on the remainder of the whole surface of the tuning-fork and support, the whole system would commence moving, and continue moving with an accelerated velocityin the direction of the force acting on the card—an impossible result. It might, indeed, be argued that this result is not impossible, as it might be said that the kinetic energy of the vibrations could gradually transform itself into kinetic energy of the solid mass moving through the fluid, and of the fluid escaping before and closing up behind the solid. But ‘common sense’ almost suffices to put down such an argument, and elementary mathematical theory, especially the theory of momentum in hydro-kinetics explained in my article on “ Vor- tex-motion,” negatives it. The law of the attraction which you observed agrees perfectly with the law of magnetic attraction in a certain ideal case which may be fully speci- fied by the application of a principle explained in a short article communi- cated to the Royal Society of Edinburgh in February last, as an abstract of an intended continuation of my paper on ‘“‘ Vortex-motion.”’ Thus, if we take as an ideal tuning-fork two globes or disks moving rapidly to and fro in the line joining their centres, the corresponding magnet will be a bar with poles of the same: name as its two ends and a double opposite pole in its middle. Again, the analogue of your paper disk is an equal and similar diamagnetic of infinite diamagnetic inductive capacity. The mutual force between the magnet and the diamagnetic will be equal and opposite to the corresponding hydro-kinetic force at each instant. To apply the analogy, we must suppose the magnet to gradually vary from maximum magnetization to zero, then through an equal and opposite mag- netization back through zero to the primitive magnetization, and so on periodically. The resultant of fluid pressure on the disk is not at each in- stant equal and opposite to the magnetic force at the corresponding in- stant, but the average resultant of the fluid pressure is equal to the average resultant of the magnetic force. Inasmuch as the force on the diamagnetic is generally repulsion from the magnet, however the magnet be held, and is unaltered in amount by the reversal of the magnetization, it follows that the average resultant of the fluid pressure is an attraction on the whole towards the tuning-fork into whatever position the tuning- fork be turned relatively to it. Your seventh experiment * has interested me even more than any of the others. It illustrates the elementary law of pressure in hydro-kinetics, not by showing effects of fluid pressure on portions of a solid bounding * Experiment 7 in Proceedings Roy. Soc. vol. xix. p. 38, or experiment 10, Phil. Mag. Nov. 1870.—F. G. 1871.] Presents. 273 surface, as all other illustrative experiments hitherto known to me have done, but by showing an effect of diminished fluid pressure throughout more rapidly moving portions of the finite mass of the fluid itself. This effect consists of a slight degree of expansion, depending on the air not being perfectly incompressible. The volume occupied by the more rapidly moving portions becoming slightly augmented, the remainder of the fluid would be condensed were the whole contained within an altogether fixed boundary. A moveable portion of this boundary (that is, the surface of the liquid in your tube) yields and shows to the eye the effect of the di- minished pressure through the rapidly moving portions. No branch of abstract dynamics has had a greater charm for the ma- ‘thematical worker than hydro-kinetics, but it has not hitherto been made generally attractive by experimental illustrations. Such refined and beau- tiful experiments as those you describe, and especially your seventh, tend notably to give to this branch of dynamics quite a different place in popular estimation from that which it has held; but what is perhaps of even greater importance, they help greatly to clear the ideas of those who have made it a subject of mathematical study. Yours truly, WiLi1AM THOMSON. Lo Presents recewed December 8, 1870. Transactions. Batavia :—Koninklijke Natuurkundige Vereeniging in Nederlandsch Indic. Natuurkundig Tijdschrift. Deel 31. Afl. 1-3. 8vo. Batavia ie) AL Soe. The Society. 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Upsal 1868. The Author. Dircks (H.) Nature-Study, as ne to the purposes of Poetry and Eloquence. 8vo. Edinburgh 1870. The Author. Fritsch (W. v.) Ziffernbeiwerk zu den graphischen Curven-Tableaux iiber die Ergebnisse des dsterreichisch-ungarischen Bergwerks-Be- triebes von den Jahren 1855 bis inclusive 1866. 8vo. Ween 1869. Supplementheft. 8vo. Wren 1870. Graphische Curven-Tableaux. fol. Wren 1870. Gulliver (G.), F.R.S. Notes of some of his Researches in Anatomy, Phy- slology, Pathology, and Botany. 8vo. London. The Author. Miller (W. A.), F.R.S. Introduction to the Study of Inorganic Che- mistry, edited by C. Tomlinson, F.R.S. 12mo. London 1871. The Editor. Regnault (V.), For. Mem. R. 8. Relation des Expériences pour deéter- miner les lois et les données physiques nécessaires au Calcul des’ Machines a feu. Tome III. 4to. Paris 1870. The Author. January 19, 1871. Transactions. Innsbruck :—Ferdinandeum fiir Tirol und Vorarlberg. Zeitschrift. Dritte Folge. Heft 15. 8vo. Innsbruck 1870. The Institution. London :—Committee of Civil Engineers. Preliminary Experiments on the Mechanical and other properties of Steel. fol. London 1868. The Committee. Institution of Civil Engineers. Catalogue of the Library. Supplement to the second edition. 8vo. London 1870. The Institution. 1871.] Presents. 279 Transactions (continued). Paris :—Société de Géographie. Bulletin. Avril-Juin 1870. 8vo. Paris 1870. The Society. Société Géologique de France. Bulletin. 2°série. Tome XXVI. No.7; Tome XXVII. No. 1-3. 8yvo. Paris 1869-70. The Society. Rome :—Accademia Pontificia de’ Nuovi Lincei. Atti. Anno 23, Sess. 1-7. 4to. Roma 1870. The Academy. St. Petersburg :—Académie Impériale des Sciences. Mémoires. Tome XV. No. 5-8, Bulletin. Tome XV. No. 1,2. 4to. St. Pétersbourg 1870. The Academy. Birt (W. R.) Outline Lunar Map. Zone IY. area a7.—Hipparchus, its characteristic features and Craterology. 4to. London 1870. The Author. Brodhurst (B. E.) The Deformities of the Human Body: a System of Orthopedic Surgery. 8vo. London 1871. The Author. Delpino (F.) Pensieri sulla Biologia Vegetale, sulla Tassonomia, sul valore tassonomico dei Caratteri Biologici e proposta di un genere nuovo della famiglia delle Labiate. 8vo. Pisa 1867. C. Darwin, F.R.S. Hall (James) Paleontology. Vol. IV. Part 1 (Geological Survey of New York). 4to. Albany 1867. The Author. Marignac (C.) Recherches sur les Chaleurs Spécifiques, les densités et les dilatations de quelques Dissolutions. 8vo. Grenéve 1870. The Author. Neumayer (G.) Results of the Magnetic Survey of the Colony of Victoria executed during the years 1858-64. 4to. Mannhem 1869. The Author. Rodwell (C. F.) . increases without limit, the series Se x +.--+-approaches zero. Therefore, as we suppose f positive, QeS* will increase without limit; and therefore as Q is supposed multiplied by an arbitrary constant, we must have Q=0. Hence the value of the integral where p, v,... are supposed fractional will also be Pe**, a being negative, and the constants in P determined as before. Next, consider the integral \? e**(z—a)—!dz a (= pe =E=ye" where x is supposed negative, « and 6 esseutially positive, 6 less than «, * tis proper here to remind the reader that the integral (" Pin In Bm—le-a8 sok (atic) Tn) does not hold good when a is negative. zZ2 284 My. W. H. L. Russell on Linear Differential Equations. [Feb. 2, y essentially negative. Then the aoa will satisfy the differential ene we + fk pr (a Brey) Y Sale —{r(B+y)—n(a+7)—»(@+B)—(a8 + By tayo} Fe — {By + pay + va +oPyesy=0. We here suppose X fractional, » aud y positive and entire. The solution of the differential equation will be atpBty 2S ETT Y= = PeSt + Qev?+ C{Peb RE € yt he ae ae Qev” Ke 12) 2 “der : where P and Q are rational and entire functions of the orders p and » re- spectively, and X,, X, functions of 2, which it will be needless to write down. The integral will consequently be equal to this expression when the arbitrary constants are properly determined. The integral cannot go on increasing as #, supposed negative, increases. Hence Q=0 and C=0, and the integral becomes 7 e*#(z—a)\—ldz i} Ga pyrieny pnt TAT BEL Oe. + Hare where A, B, &c. are constants to be determined. We find, as before, =|" (z—a)—ldz CH Brees yet Pa ee (e—a)*—Idz f— i (z—By(e— yt} * &c. = &e. And thus the integral is completely abies I will now consider the differential equation It is easily seen that this equation is satisfied by the integral = ve) ee +au dy a —O The solution of the differential equation is y=C, cos ax + C, sin an+ C, {cos aafe” sin ax dx— sin ax/e cos aa dais and these must be equivalent. If we put —w for u in this equation, we easily see that . D o—nu?+au Jy rae DP o—nur—axu fy : aie hence the integral is unchanged if —# is put for x, and therefore C,=C,=0. 1874.] Measurements of Specific Inductive Capacity of Dielectrics. 285 ; Hence — : : : we ‘ ‘ : cae : ett. eee du Ap Rl Wa ae a eine oi putting 2=0, | dn Vn Theat this equation, and choosing the arbitrary constant so that c re) = de = (ee e7 dy = — ve. —M may vanish when 2 is infinite, aan c= NM ren amen Vn Hence se shall have A (OP cars nm hu hs ee ‘te oe =2 Neen COS aavetn dt ea p2, Hn | Nn which last integral is exceedingly well known. It is manifest that we can we Ee ~2U2+2Uu day : reduce the integral ( 5, to this by the method of partial ce ofl efrite= | fractions. In concluding this paper, I desire to express the obligations I am under to Spitzer’s § Studién.’ IT. “Measurements of Specific Inductive Capacity of Dielectrics, in the Physical Laboratory. of the University of Glasgow.” By Joun C, Gipson, M.A., and THomas Barctay, M.A. Com- municated by Sir Wirtras THomson. Kcceived November 23, 1870. (Abstract. ) This paper describes the instruments and processes employed in a series of experiments on the specific inductive capacity of paraffine, and the effect upon it of variations of temperature. The instruments described are the platymeter and the sliding condenser. 'The former cf these was, in a rudimentary form, shown to the Mathematical and Physical Section of the British Association at its Glasgow Meeting in 1855, by W. Thomson. It consists of two equal and similar condensers employed for the comparison of electrostatic capacities. The sliding condenser is a condenser the capacity of which may be varied by known quantities by altering the effective area of the opposed surfaces. By means of these two ieramiente: along with the quadrant electrometer, the capacity of a condenser may be determined by equalizing the sliding condenser to it. The method of working, and the electrical actions upon which it depends, are described in detail. In Be 6/0 : The Rev. Canon Moseley on the ‘[Feb. 2, order to determine the capacity of the sliding condenser at the lower extre- mity of its range, a spherical condenser, so constructed that its capacity could be accurately determined in absolute measure, was employed. An apparent discrepancy in the results obtained, arising from an inequality in the condensers forming the platymeter, is then considered, and the method of deducing the true result investigated. A series of experiments is then described which gave 1:975 as the specific inductive capacity of paraffine, that of air being taken as unity, but failed to show whether this alters with variations of temperature. An improved form of condenser, composed of concentric brass cylinders with paraffine for the dielectric, and the results obtained from it, are then described. The measurements made at different temperatures show no variation of specific inductive capacity. In order to allow to the paraffine freedom of expansion with temperature, another form of condenser was employed, and the same results obtained. A series of experiments was then made on the expansion of paraffine with tempera- ture, in order to estimate the effect of this upon the capacity of paraffine condensers. As a meanof the results, it was found that the linear expan- sion of paraffine at 9° C. is ‘000237 per degree. Some further measure- ments of the cylindrical condenser were made with the same result as before. Thus all the measurements of this condenser made at temperatures ranging from —12°°15 to 24°35 C. show no variation of specific inductive capacity of paraffine with temperature. This was found to be 1°977, that of air being taken as unity. In a note added to the paper a description is given of an improved form of sliding condenser. III. “On the Uniform Flow of a Liquid.” By Henry Mosetety, M.A., D.C.L., Canon of Bristol, F.R.S., and Corresponding Member of the Institute of France. Received December 1, 1870. (Abstract.) The resistance of every molecule of a liquid at rest which a solid (by moving through it) disturbs, contributes its share to the resistance which the solid experiences ; so that the inertia of each molecule so disturbed and its shear must be taken into account in the aggregate, which represents the resistance the liquid offers to the motion of the solid. The motions com- municated to the molecules of a liquid by a solid passing through it, and the resistances opposed to them, however, are so various, and so difficult to be represented mathematically, that in the present state of our knowledge of hydrodynamics the problem of the resistance of a liquid at rest to a solid in motion is perhaps to be considered insoluble. As it regards the opposite problem of the resistance of a solid at rest to a liquid in motion (as in the case of a liquid conveyed through a pipe), there are in like manner to be taken into account the disturbances created by that re- 1871. ] Uniform Flow of a Liquia. sistance in what would otherwise have been the motion of each individual molecule of the liquid so disturbed. This problem, however, is by no means so difficult asthe other. There is, indeed, a case in which it admits of solution. It is that of a liquid flowing from a reservoir, in which its surface is kept always at the same level, through a circular pipe which is perfectly straight, and of the same diameter throughout, and of a uniform smoothness or roughness of internal surface, and always full of the liquid. The liquid would obviously in such a pipe arrange itself in infinitely thin cylindrical films coaxial with the pipe, all the molecules in the same film moving with the same velocity, but the molecules of different films with velocities varying from the axis of the pipe to its internal surface. The direction of the motions of the molecules of such a liquid being known, and all in the same film moving with the same velocity, which velocity is a function of the radius of the film, and the law of the resistance of each film to the slipping over it of the contiguous film being assumed to be known, as also the head of water, it is possible to express mathematically (1st) the work done per unit of time by the force which gives motion to the liquid, and (2nd) the work per unit of time of the several resistances to which the liquid in moving through the pipe is subjected, and (8rd) the work accumulated per unit of time in the liquid which escapes— and thus to constitute an equation in which the dependent variables are the radius of any given film, and the velocity of that film. This equation being differentiated and the variables separated, and the resulting differen- tial equation being integrated, there is obtained the formula mee Dev Ti 2 where v is the velocity of the film whose radius is 7, and », that of the central filament, and / the length of the pipe—the unit of length being one metre, and of time one second. The method by which the author has arrived at this Bi mula is substan- tially the same as that which he before used in a paper read before the Society on the ‘ Mechanical Impossibility of the Descent of Glaciers by their weight only,” and which he believes to be a method new to me- chanical science. It was indeed to verify it in its application to liquids that he undertook the investigations which he now submits to the Society, which, however, he has pursued beyond their original object. The recent experiments of MM. Darcy and Bazin* have supplied him with the means of this verification. These experiments, made with ad- mirable skill and precision, on pipes upwards of 100 metres in length, and varying in diameter from 0™:0122 to 0™-5, under heads of water varying * Recherches Expérimentales relatives au mouvement de ]’Hau dans les Tuyaux, par H. Darcy: Paris, 1857, Recherches Hydrauliques, par MM. Darcy et Bazin; Paris, 1865, 288 The Rev. Canon Moseley on Uniform Flow. [ Feb. 2, in height from 0™:027 to 30™°714, include (together with numerous experi- ments on the quantity of water which flows per second from such pipes under different conditions) experiments on the velocities of the films of water at different distances from the axes of the pipes, made by means of an improved form and adaptation of the well-known tube of Pitot. These last-mentioned experiments afford the means of verifying the above-men- tioned formule. With a view to this verification, the author has compared the formula with sixty of the experiments of M. Darcy, and stated the re- sults in the first two Tables of his papev. The discharge per 1” from a pipe of a given radius may be esleniaige from the above formula in terms of the velocity of the central filament. This calculation the author has made, and compared it with the results of eleven of M. Darcy’s experiments. Where in the formula which thus represents the discharge from a pipe of given radius, in terms of the velocity of the central filament, the radius is made infinite, an expression is obtained for the volume of liquid of a cylindrical form, but of infinite dimensions (laterally), which would be put in motion by a single filament of liquid which traversed its axis ; and, con- versely, it gives the volume of such a liquid in motion which would be held back by a filament of liquid kept at rest along its axis. Thus it explains the well-known retarding effect of filaments of grass and roots in retarding the velocities of streams. Itis the relation of the velocity of any film to that of the central fila- ment which the author establishes in the above formula. To the complete solution of the problem itis necessary that he should further determine the actual velocity v, of the central filament. This is the object of the second part of his paper. This velocity being known, the actual discharge per 1" is known. The following is the formula finally ar rrived at :— cat __ 25 OR Q=C. Ee = ~1]R h? Uf, 7 where Q= discharge per 1" in cubic metres. R=radius of pipe in metres. ~ =length of ditto. h =head of water. . C =aconstant dependent on the state of the internal surface of the pipe. | | The values’ of this constant C, as dedueed from the experiments of M. Darcy are given, ist; for new cast-iron pipes ; 2nd, for the same covered with deposit ; 3rd, for the above cleaned ; 4th, for iron pipes coated jntempally with bitumen ; 5th, for new leaden pipes ; : " 6th, for glass pipes. 1871.] Lffect.of Exercise upon the Bodily Temperature. 989 The author compares this formula with sixty-two of M. Darcy’s experi- ments, and records the results of this comparison in the last three Tables of his. paper. The paper concludes with an investigation of the rise in the eecuperatne of a liquid flowing through a pipe caused by the resistances which its coaxial films oppose to hea motions on one another (or; as it is termed, their frictions on one another) and on the internal surface of the pipe. The pipe is in this investigation supposed to be of a perfectly non-con- ducting substance. February 9, 1871. General Sir EDWARD SABINHE, K.C.B., President, in the Chair. The following communications were read :— I, “On the Effect of Exercise upon the Bodily Temperature.” By T. Cuirrorp AtiButt, M.A., M.D. Cantab., F.L.S8., Member of the Alpine Club, &. Communicated by Mr. Busx, Received November 12, 1870, (Abstract.) The object of the author in carrying out the experiments recorded in the present paper was to inquire whether the regulating-power of the organism held good under great variations of muscular exertion. For this purpose he made frequent daily examinations of his own temperatures during a short walking tour in Switzerland, and found that the effect of continuous muscular exertion upon himself was to sharpen the curve of daily varia- tion—the culmination being one or two tenths higher than usual, and the evening fall coming on more rapidly and somewhat earlier. Charts of the daily temperatures were handed in with the paper. The author made re~ ference also to some observations of M. Lortet, which differed from his own. These observations, which did not come into Dr. Clifford Allbutt’s hands until his own experiments were partially completed, were adduced by M. Lortet to prove that the human body was very defective in regu- lating-power under the demands of the combustion needed to supply the force expended in muscular exertion. Dr. Clifford Allbutt’s results were -very decidedly opposed to those of M. Lortet; for only on two occasions did he note the depressions of temperature which M. Lortet regards as constant. It would seem, however, that the body is more or less liable to such depressions when engaged in muscular exertion; but the cause of them is very. obscure. Of the two low temperatures noted by the author, one occurred during a very easy ascent of lower slopes, and the second was observed during a descent. The author thinks that they may be due to some accidental deficiency in combustion, and inquires whether the capa- city of the chest in different individuals may account for the varying in- 290 Prof. J. Phillips’s Observations of the [Feb..9, fluence of muscular effort upon them, and perhaps for the earlier or later sense of fatigue. The sphygmographic tracings added by M. Lortet to his temperature-charts seemed to show a great inadequacy of circulation. II. “Observations of the Eclipse at Oxford, December 22, 1870.” By Joun Puitiirs, M.A., D.C.L., F.R.S., Professor of Geology in the University of Oxford. Received December 28, 1870. At my observatory, situated about one third of a mile eastward from the great establishment founded in the name of Dr. Radcliffe, the beginning of the eclipse was obscured by a passing cloud: the end was recorded at 13° 38' 38" = 1" 35' 0"-9 Oxford mean time. The progress of the obscuration was observed at unclouded intervals in the first half of the period, continuously during a clear sky in the latter half. Finding it impracticable to observe and measure with ordinary micrometers in the early part of the phenomenon, I arranged to throw the image on a screen, and make my measures on it. The driving-clock was affected by the extreme cold, so as to make it difficult to keep the sun’s image to one place, and it was convenient for other reasons sometimes to shift the image vertically ; the method which I employed, however, was independent of these displacements, and allowed of as many measurements of the cusps as might be desired. It consisted simply in marking at any moment with pencil the situation of the cusps on the screen, and appending to each dot the time by the sidereal clock. Joining, after the eclipse, these dots by a straight line, and then transferring a parallel line of equal length to meet internally a circle representing the limb of the sun, of the same diameter as the solar image, the chord of the cusps at the given time was obtained, from which, by an easy method, the place of the moon’s centre at the moment was derived. The apparent diameters of the sun and moon were obtained by measure of arcs on the screen. The diagrams exhibit the whole process. In diagram fig. 1, four of the lines are drawn from the dots on the screen, AA, B B, CC, DD. In fig. 2, equal and parallel lines are transferred to the solar circle, whose centre is S, so as to touch it internally at A’ A’, B’ B’, C’'C’, D' D’. For each of these lines the centre of the moon’s place is marked (A”, B”, C", D") ; thus the line of the motion of the moon’s centre is given, and the phase of greatest obscuration determined. The line of motion of the moon’s centre is obtained by ruling through the mid points between A” and B”, B” and C", C” and D”. The point on this line reached by the moon’s centre at the moment of greatest ob- scuration is found by bisection in M. Drawing through M and § the bi- secting line of greatest obscuration, the length of the sagitta ms is deter- mined. 1871.] Eclipse at Oxford, December 22, 1870. It is found by these observations that, The sun’s diameter being taken at ............ 530 Hhat.of the, MmOOWNs)/ a awl. cretemiges 2.8 sive esiepcinia 540 Fig. 1. AA, BB, CC, DD, are lines joining the dots marking the cusps at four suc- cessive epochs during the eclipse. 2. A’ A’, B'B’', C' C', D' D’, are four lines equal and parallel to A A, BB, CC, D D in fig. 1, and made to touch internally the solar circle, whose centre is S; ms the sagitta at the moment of greatest obscuration. The moon’s path passes below A”, above B”, and nearly coincides with O" and D", which are the places of the moon’s centre for the cusps A’, B’, O', D’. These numbers, according to the proportions given in the Nautical Almanac for the Radcliffe Observatory, would have been :— iometer of the:sun oii visiia kh. es ool een 530°0 Diameter ofthe moon” ea. yee hs Osk hos bss 538°8 Mensth of sagittal egies Gide MLE A Ooe ke 99-1 The agreement is quite close enough to justify the belief that, in skilful hands, the method described may be in some cases very useful, it being by no means limited to eclipses. It is so simple that one can hardly suppose it not to have been already employed; but I have met with no notice of such being the case. During the progress of the eclipse three thermometers were observed: One north of the house, screened from the sun and sky, sank from 26° at 11° 40™ to 24°4 at 12 25™. One south of the house, indirectly in- fluenced by solar radiation on neighbouring objects, rose from 26°75 at 11 to 27°°8 at noon, then sank to 26° at 12" 40”, and rose to 27°°3 at 1° 35™, A third, on grass open to the sky, sank from 27°'8 at 11" 40™ to 23°°5 at 1" 25", and remained at this point till 1" 35". Though on a limited scale, the influence both of solar and sky radiation is traceable in these observa- tions. 292 ” Mr. Ee J. Reed Gn ‘the Distribution © [Feb. 9; III. “On the Problem of the In- and Circameer ibed Triangle.” By ae CaYLey, FR:S. Received December 30, 1870. CE py) Oe. a Wate Rae) ee OR ee wee ( Abstract. }- ~The problem of the in and circumscribed triangle is a ies case of that of the in- and circumscribed polygon: the last-mentioned problem may be thus stated—to find a polygon such that the angles are situate in and the sides touch a given curve or curves. And we may in the first instance inquire as to the number of such polygons. In the case where the curves containing the angles and touched by the sides respectively are all of them distinet curves, the number of polygons is obtained very easily and has a simple expression; it is equal to twice the product of the orders of the eurves containing the several angles respectively into the product of the classes of the curves touched by the several sides respectively ; or, say, it is equal to twice the product of the orders of the angle-curves into the product of the classes of the side-curves. But when several of the curves become one and the same curve, and in particular when the angles are all of them situate in and the sides all touch one and the same curve, it is a much more diffi- cult problem to find the number of polygons. The solution of this problem when the polygon is a triangle, and for all the different relations of identity between the different curves, is the object of the present memoir, which is accordingly entitled “‘On the Problem of the In- and Circumseribed Tri- angle;’? the methods and principles, however, are applicable to the case of a polygon of any number of sides, the method chiefly made use of being that furnished by the theory of correspondence, . IV. “On the Unequal Distribution of Weight and Support in Ships, and its Effects in Still Water, in Waves, and in Exceptional Positions on Shore.” By E. J. Rexp, C.B., Vice-President of the Institution of Naval Architects. ‘Communica by Prof. G. G. Stoxzs, Sec. R.S. Received December 31, 1870. (Abstract.) The object of this paper is to bring within the grasp of calculation what the author considers a much neglected division of shipbuilding science and art, by investigating the actual longitudinal bending- and shearing-strains to which the structure is exposed in ships of various forms under the varying conditions to which all ships are more or less liable. The weakness exhi- bited by many ships has long pointed to the necessity of further investiga- ‘tion in this direction ; and two modern events (the use of iron and steel in shipbuilding, and the introduction of armoured ships) have added much to the urgency of the inquiry. After glancing briefly at the state of the question as presented in the writings of Bouguer, Bernoulli, Euler, Don Juan D’ Ulloa, Romme, Dupin, (871.]. - - of Weight and Support in Ships. = = 298 ‘and Dr. Young, the author proceeds to show that the introduction of steam ‘as a propelling agent, and of largely increased lengths and proportions for ships, has brought about a comparative distribution of weight and buoy- ancy very different from that which those writers contemplated. He has taken the cases of three or four typical modern ships, and has had the re- lative distributions of the weight and buoyancy very carefully and fully ‘calculated and graphically recorded. Owing to the great labour involved, ‘only the most meagre and unsatisfactory attempts to measure and exhibit the actual strains of ships had previously been made; and the author’s results are wholly unlike any that have before been worked out and published. The first case is that of the royal yacht ‘Victoria and Albert,’ which re- presents the conditions of long fine-lined paddle-steamers, with great weights of engines, boilers, and coals concentrated in the middle, combined with very light extremities. The second case gs that of the ‘Minctaur,’ ‘which represents long fine-lined ships with great weights distributed along ‘their length. The iron-clad ‘ Bellerophon’ is the third case, representing shorter ships with fuller lines and very concentrated midship weights; and the last case is that of the ‘Invincible’ class, in which the weights of armour &c. are still more concentrated. All these ships are divided into ‘very numerous short lengths; and the weight of hull, weight of equipment, and buoyancy or displacement of each short length are separately calculated, curves of weight and buoyancy being constructed from these items used as ordinates. A third curve, of which the ordinates are the differences be- ‘tween the curves of total weight and of displacement, known as the curve ‘of loads, is constructed. By summing the ordinates, or calculating the areas of this curve, from point to point, a curve of shearing or racking forces is formed; and by employing the products of the areas of the curve of loads (taken step by step) into the distances of their centres of gravity from one end as ordinates of a new curve, a curve of bending-moments is constructed. _ These operations are performed for all the ships previously named, first when they are floating in still water, next when they are respectively float- ing on the crests of waves of their own lengths, and thirdly when they are floating in the hollow of two adjacent waves of those lengths. The maxi- mum breaking-strains of all the ships when supported on shore, first at the extremities and next at the middle, are also calculated, and compared with the still-water and sea strains. In considering still-water strains, the author shows that remarkable con- trasts of strain occur between ships light and laden, and that the theories of former writers on the subject require to be greatly modified. In some cases the breaking-strain is increased as the ship is lightened. In dis- cussing the shearing-strains, he points out that the sections of maximum shearing-strain in a ship coincide with the balanced or “water-borne sec- tions’’ (at which the weight and buoyancy are equal), and that in most ships the number of these sections is equal. The position of absolute 294 On the Distribution of Weight and Support in Ships. [Feb. 9, maximum shearing-force occupies very different positions in different types of ship. Sections of zero shearing-force coincide with ‘sections of water- borne division,” on either side of which the weight balances the buoyancy ; and their number is usually odd. Heafterwards shows that maximum and minimum bending-moments are experienced by sections of water-borne division, and that between two sections of maximum “ hogging ’’-moment there must fall either a section of minimum hogging-moment or a section of maximum “‘sagging’’-moment, and that it is an error to suppose (as all former writers on the subject have done) that the absolute maximum bending-moment falls amidships. In the ‘ Victoria and Albert’ the last- named moment is in the forebody ; in the ‘ Bellerophon’ and ‘ Audacious’ it is in the afterbody. The effect of the horizontal fluid pressure in the longitudinal bending-moments is also discovered, and shown to be important. The dynamical aspect of the question—showing the strains brought upon ships at sea—is admitted to be both the more difficult and the more im- portant. In discussing the strains, the author calculates them approxi- mately under the following assumptions :—(1) That for the moment the effect of the ship’s vertical motion may be neglected. (2) That for the moment the ship may be regarded as occupying a position of hydrostatical equilibrium. (3) That the methods of calculating bending- and shearing- strains previously used for still water may be employed here also, in order to approximate to the momentary strains. The following particulars of the ‘ Minotaur’ and ‘ Bellerophon’ floating on the crests and in the hollows of waves of their own length respectively and of proportionate heights, illus- trate the results to which the calculations before named have led for those ships. On Wave-crest.. ‘ Minotaur.’ ‘ Bellerophon.’ Excess of weight forward 1,275 tons. 445 tons. ” ” Be oe ahs oe 1,365 ” 999 55 oe buoyancy amidships. Z O40 v6 1,000) = Maximum shearing-strain . 1,365 559 - bpending-moment 40,300 foot- tons.|43,600 foot-tons. In Wave-hollow. Excess of buoyancy forward .. | 685 tons. | 640 tons. oa re aft ‘Ves OLE 695.7. 600 ,, a weight amidships ..| 1,380 ,, 1 2400 Maximum shearing-strain .... 695 610°; if bending-moment ..| 74,800 fonts tons. lee ,800 foot-tons. The strains of ships supported on shore, first at the extremities and then | at the middle, are next investigated. The following Table gives the ap- 1871.] Dy. A. Rattray on the Effects of Change of Climate. 295 proximate quantitative values of the shearing-forces and bending-moments obtained for the three ships, ‘ Minotaur,’ ‘ Bellerophon,’ and ‘ Victoria and Albert’ :— ‘ Minotaur.’ ‘BelleropLon’ |‘ Victoriaand Albert.’ | ek, es ee ee ees, | Shearing-|} Bending- Shearing. Bending- | Shearing-| Bending- force. | moment. | force. | moment. | force. | moment. Displace- | Displace. | Displace- | Displace. Displace- | Bere: ment. |X length.| ment. |x length.| ment. | X length. Hapstallwater <6. 6... 3 ay as ds | oe | od | oh On a wave-crest .......... 1 ay ae 2 as - In a wave-hollow ........ te i | ok os i ame | Supported at the extremities.| 3 + 4 x - a Supported at the middle....| 3 | xan 4 ae 2 ae | | February 16, 1871. General Sir EDWARD SABINE, K.C.B., President, in the Chair. The following communications were read :— I. “On some of the more important Physiological Changes induced in the Human Economy by change of Climate, as from Tempe- rate to Tropical, and the reverse” (concluded)*. By ALEXANDER Rarrray, M.D. (Edinb.), Surgeon R.N., H.M.S. ‘ Bristol.’ Communicated by Mr. Busx. Received January 6, 1871. IV. The influence of Tropical Climates on the Kidneys and Skin. None of the organs of the body are more visibly affected by great changes of climate than these, and their secretions, the urine and perspiration. As with the lungst and other internal viscera, the congestion of the kidneys lessens, while that of the skin increases, when the blood is attracted to the surface by heat. The reverse happens when it is driven inward by cold. This involves their special and vicarious, waste-product and water-excreting functions alike. In the tropics the skin doubtless excretes much of the water thrown off by the kidneys and lungs in colder regions, as well as the nitrogen and carbon of the former, and carbonic acid of the latter. The elimination of surplus water, one of the most important uses of all of the four great depurating organs, is largely effected by these two. Their in- timate relation in this office in cold latitudes is already known. We shall here attempt to show what it is in the tropics. * Continued from Proceedings of the Royal Society, June 16, 1870, vol. xviii. p. 529. t Ibid. p. 523. 296 - Dr. A. Rattray on the Effectsof - . - [Feb. 16, The following experiments were made on myself (zt. 39), on a voyage from England to Bahia (lat. 11° S.), between June and September 1869. During 24 days, from Plymouth to the thermal Equator, drink (tea or coffee) being limited to 39 oz. daily, the urine gradually decreased from 39 to 30 oz., which merely proved that in semitropical, as in temperate climates, free fluid is chiefly thrown off by the kidneys, and that this diminishes as the heat increases. The following Table gives the results of the two subsequent days, while passing through the equatorial doldrums or greatest heat, the drink being suddenly ieee to 88 oz. daily : — Taste I.—To show the Urine excreted at the Equator. 9 A.M. : 9 P.M. Aye- Night urine. Day urine. - Totals. Locality. Ree anata |e eee | a Quan- Quan Quan- is tity. [SP- 8" ‘tity. [BP 8") tity. [SP- St SS SSeS oft the African Coast, Equatorial doldrums 80 July 14; 16 15 204 14 364 4) dat. ALO GN: oe sauect os 81 | July 15 164 | 13 21 8 oly _ Thus nearly 37 oz. were excreted by the kidneys, leaving 51 oz. to be accounted for. Now the bile is scarcely if at all increased in the tropics, - so that the liver gives little aid. Dalton* gives #5 of the drink as the _ average thrown off in this form and by the bowels in temperate latitudes. . Taking this for the tropics also, allowing a little increase for bile, we have 4:4 0z. And reducing the water exhaled by the lungs in the temperate zone (which, according to Dalton, is ¢ of the drink or 22 oz.) by the same ratio as the respired air, viz. 11 per cent. or 2°42 oz., we have 19°58 oz. as that for the tropics. The sum of these two is 23°98 oz. Then the 51 oz. not thrown off by the kidneys — 23°98 oz. excreted by the lungs and bowels gives 27°02 oz. for the skin to exhale. So that the 88 oz. free fluid were got rid of thus :— Urine 37 oz., skin 27°02 oz., lungs 19°58 oz., feeces 4°4 oz, Had the water in the solid ingesta been reckoned, a difficult matter on shipboard, the experiment would have been more satisfactory. But this gives a fair approximation, inasmuch as any excess from this source would - only have. gone to. increase the perspiration. The relative excretion of free fluid-by the skin, kidneys, lungs, and bowels, thus, differs in temperate and tropical latitudes, as they doubtless do in _ arctic regions (Table II.). * Hooper, ‘ Physicians’ Vade Mecum.’ 1871.] Change of Climate on the Human Economy. 297 Tasxe II.—To show the relative excretion of free fluid in Temperate and Tropical latitudes. Organ. Temperate zone*. Tropics. oz. per cent. oz. per cent. Kidneys ...... (about) §—=45:25=59:54 |(about) $=3(° =42-04 Punes......... (somewhat (somewhat | more than) }=20:-50=26:97 | more than) 3=19°58= 22-25 BVO sos aie 0s (rather less than) ss= 650= 8:55 5 =27:02=30°7 Bowels ...... (about) so= 375= 493 ee Gees SS Gr While the urine thus decreases from 593 to 42 per cent., the perspiration rises from 83 to 30 per cent., there being a slighter fall of 43 per cent. from the lungs, and a trifling rise from the bowels. The kidneys are thus the chief eliminators of surplus water in the tropics as in temperate regions ; but in the former it is the skin, as in the latter it is the lungs that rank next. If suddenly stressed, however, by excessive imbibition, and the safety-valve action of the kidneys or skin be brought into play, these pro- portions doubtless differ. Will they hold good for permanent residents in the tropics, foreign or native ? The increased perspiration in the tropics or in artificial heat, and dimi- nished urinary and pulmonic water-excretion by 22 per cent., is equal to a proportionate increase in the cutaneous circulation and corresponding with- drawal of blood from the kidneys to the extent of 174 per cent., and lungs of 43 per cent. Moreover this diminished exhalation of watery vapour from the lungs, by vicarious action of the skin, still further decreases the amount of blood circulating through them, already shown to be reduced by 12:24 per cent., or 16°62 fl. oz. by a diminished excretion of carbonf. The total decrease in the lung circulation is thus :— 16°62 fl. oz. + 6:42 ,, (4:72 per cent.) == 23:04 fl. oz. as the total permanent withdrawal of blood from the lungs by an average temp. of 80-83° F. These facts appear highly interesting in the etiology of these and other important internal and external organs, as well as hygienically and thera- peutically suggestive. The following results of the entire voyage from Bahia to England on a * Hooper, ‘ Physicians’ Vade Mecum.’ In Dalton’s experiment the amount of free fluid drunk was 76 oz., and in the aboye 88 oz. daily, The proportionate results, however, are the same in both. tT Proc. R, 8. 1870, vol. xviii, p. 515, VOL. XIX. Qa 298 Dr. A. Rattray on the Effects of [Feb. 16, daily allowance of 88 oz. free fluid (Table III.), will show that this par7- passu increase and decrease in the perspiration and urine are by no means uniform on going to or quitting the tropics, but oscillate considerably in all latitudes, both in quantity and contained solids, even in adjacent days. Tasie IiI.—To show the quantity and contained solids of the Urine in a voyage across the tropics of 34 days. | Urine. | ales Morni Eveni Totals Date. | 728° | Locality. area le: Con- ae Q Quan Quan | yey fe Sp. er. tity. Sp. gr. tity. Sp. gr.) solids. 1869 2 grains. Aug. 8.| 764 | Bahia sgt) OL TF | abe TS) Ria a4 5 38 8 82 | 6:39 | 503-97 » 10.) 772 | », 135 ,,| 38 5 42 6 80 | 5°52 | 409-61 Eo etka cee |. ty Leela, Wp oO 6 46 5 82 | 544 | 419-85 ah 2G'F go? bial 9 10 46 5 65 | 646 | 399-78 we ot 28 as ays 15 ee 4 35 7 79 | 5:32 | 404-49 yg | Oe, 4) aD 4 32 8 74 | 572 | 378-89 pe koe Mile Tay ere oe, OO. 5 42 4 78 | £49.) 31989 » 16.) 7385 | » 088,, | 42 7 31 4 73 | 572 | 3873-77 retails a0 » ABI! BF 4 29 7 66 | 5°31 | 368-65 es Oe MOF | a Ok ,, | 2 42 5 28 a 70 | 58 | 3858-41 FeO.) 2k » 40 ne 20 9 39 6 59 | 701 | 423-79 » 20.) 813 | » TI17,,| 20 9 29 8 49 | 840 | 494-61 3 21.) 80 i) VBBD 5, Se 4 39 4 71 | 4 290°53 eek Ol » 10°52 ,,; 144} 10 38 4 52 | 5°71 | 266-25 Pe eo OL Paes de Aa Ra PG 7 30 5 62 | 5°87 | 317-45 Poe Coe | 4, sot 53) AL 4 38 | 4 79 | 40 | 323-26 yee) Ser | iy GAD 4, | 2Ok fh 21 9 431 | 7:96 | 361:56 ay 20.) Se, bi as ASAD | 49 4 37 4 56 | 40 | 229-14 eS We fe: ue: lar 4 23 4) 50 | 63 | 301°52 fy OE Se Th. ere «,, f Be 8 35 ok | 59 | 5:33 | 30209 Per 0k 4 2615 |, > 26s 7 321 | 4 59 | 534 | 302-09 ye 2 U5 Bers Se ASR ns) 6 62 3 87 | 386 | 355-99 oL.| 79 7 a OO pt ae 6 53 4 72 | 4:52 | 294-62 Sept. 1.] 79 Le OR, els toe 4 53 4 7. | 40) | Sto-t7 i a} 0 22 S0d8.5,) 12 11 37 4 49 | 5°75 | 250:89 POH Oe Ni OG a tl 8 44 4 62 | 5:16 | 317-45 ua 745. , Bont .,| As 7 53 4: 66 | 459 | 270-06 » 9| 733 | 4, 3458 ,, Sg me AES » 90°20 ,,{ 20 8 51 4 71 | 512 | 362-47 Ge) ae yaet2o, 7 1b 6 34 4 49 | 461 | 200-50 seh eel he » oooes| AZ 5 30 5 50 | 5:0 — | 255-26 de Ob. », 4422 25 5 48 5 73 | 50 | 371-68 Paar’ aa 39) PAOD 4) 14 8 56 5 70 | 56 | 857-36 7 do. | G0 Fe 2200 ro pmaay ier 8 27 6 62 | 545 | 31652 Thus on three consecutive days, taken at random, we find 49, 71, and 52 fl. oz., with 494, 290, and 266 grains of solids. The decrease in the latter, as well as in the fluid, is due partly to the reduced ingesta, and partly to the vicarious action of other organs, especially the skin and liver—and 1871.] Change of Climate on the Human Economy. 299 doubtless involves not only the urea and chloride of sodium*, but all of its” ordinary ingredients. Both would be far more regular if the system could. be kept day by day in strictly similar conditions as to exercise, clothing, draughts, food, and especially drink—a difficult matter at sea, though pos- sible on shore. So that by limiting the drink and increasing it only as thirst prompted, the quantity of urine would keep at a uniform and perhaps healthier standard. ‘The individually different quantities necessary to ac- complish this may be easily ascertained. Thus, allowing 25 oz. free fluid to be what my system requires daily in the average temperature of London (50° F.), the addition of 1 fl. oz. for every degree above, or its deduction for every degree below that, would keep the urine pretty equable, even though its specific gravity and solids might alter (Table IV.). Taste [V.—To indicate the daily quantity of drink necessary to keep the Urine nearly alike in Temperate and Tropical latitudes. Temperature of air (F.) ...... 80°. |; 40° . | 50°.) 60°. b: 70°. 4 802. 1 908 Free fluid required ............ 5 oz. | 15 oz. | 25 oz. | 35 oz. | 45 oz. | 55 oz. | 65 oz. This fact was proved by an experiment (of which Table V. is a synopsis) made in the Pacific in 1860-61, during a passage from Valparaiso (lat. 33°S.) to Vancouver (lat. 48° N.), when the drink was not kept uniform through- out as in Table III., but increased or decreased, as here indicated, with the desire. TaBLe V.—To contrast the Urine at the Equator and North and South Temperate Zones. Specific pravity |Quantity of {in | case. 7 cases. 1s, ere OZ. Aversge cf 7 days furthest south (lat. 33°), temp. 68° F....) 10183 | 36 f F near equator (lat. 5°), ,, -78° ¥....; 10132 45:3 i i furthest north (lat. 53°), ,, 58° F....| 10177 443 Here both the quantity and specific gravity increased somewhat ; so that the urine is perhaps not so often or much diminished in the tropics as usually believed. It is so when the drink is stinted, and when, though ample, it is not increased and decreased with the temperature (Table III.); but when this is done it remains pretty uniform (Table V.), asit often does even when taken inexcess. It isnot so much the nephritic as the cutaneous secretion which alters with variations in the amount of drink in the tropics, and in temperate climates the reverse. The functionally excited skin acts as a * Dr. Forbes Watson and Becker, as quoted in Parkes’s ‘ Practical Hygiene.’ DA 300 Dr. A. Rattray on the Effects of [Feb. 16, safety-valve for the kidneys in warm, as the latter do for the former in colder ones. While the perspiration depends much on the temperature, the urine is most influenced by the drink. Although heat, or its absence (cold), is thus the chief agent in causing these fluctuations, the humidity, velocity, &c. of the air are not altogether negative. The first acts by sti- mulating or checking the sudatory glands, and all three by favouring or Opposing evaporation. Frequent change of climate tends to develope the ordinary and safety-valve range of action in both organs. In these facts lie several important hygienic and therapeutic indications for the tropics, with a view to prevent or lessen distressing hyperzemia of the skin and excessive perspiration, both the result of undue imbibition, and the latter highly dangerous when suddenly checked, and a frequent cause of disease. By them the reason of the efficacy of tropical, and especially subtropical climates in the prevention when imminent, and cure or relief when actually present, of many diseases of internal organs, not of the abdomen alone, but of thoracic ones, is explained. The sanatory heematic and secretive de- rivative action of natural (tropical) and artificial heat has been already pointed out with regard to the lungs*. Might not the practical phy- siclan more frequently act on this hint as to the means and extent by which both the circulation and the function of diseased or over-taxed in- ternal organs may be relieved by thus transferring their blood-current and secretion to sounder ones? Is not this great and general law of a deriva- tion of blood from internal to external organs under heat, and the reverse under cold, the soundest and most philosophical basis on which to erect a new, safe, satisfactory, and permanent system of therapeutics and hy- gienics ? V. The Influence of Tropical Climates on the Weight and Strength. Besides the already discussed functional, vascular, and other changes in the lungs, skin, kidneys, and other organs of vegetable life, which follow a transition from temperate to tropical climates, various phenomena affecting those of animal life are also common—e. g. languor of body and brain, and generally a loss of weight. More tardy and less evident, but equally worth study, these are not due, like the former, to the general diversion‘in the blood-current from internal to external parts, but to changes in the blood itself and the tissues which it nourishes, to be hereafter investigated. Occasionally an individual fattens on going to the tropics, and, instead of losing, gains health and strength. Again, acorpulent person may decrease considerably in weight, while his health, so far from impairing, actually improves. But such cases are exceptional, and, doubtless, consist merely in vitally unimportant fluctuations in the adipose tissue ; and as a rule the issue includes a loss in both respects, which, if not disease, is closely allied to it. An opposite result usually follows a contrary change of climate. * Proc, R, 8, 1870, vol. xviii. p. 520. 1871.] Change of Climate on the Human Economy. 301 The following experiments to illustrate this were made in H.M.S. < Sala- mander,’ during a voyage of five months to, anda subsequent stay of three years on the east coast of Australia, while making triannual trips between Sydney (lat. 34°) and Cape York, Torres Strait (lat. 103°S.), a distance of 1700 miles in a nearly north and south direction. The crew numbered 209, their ages being :— between 15 and 25 (period of growth) ...... 129 (61°72 per cent.). e Bol 38 (oo (AGULIE ARE). Pee ok 638 BOM een) edt ,,-- 20> (lst period of decline)... 41) 16)4.(7°06 64,8). 5S (hd) 0 eg eeee ws PA GHeameiee ys Thus 192 (91°86 per cent.) were under thirty-five, which may be con- sidered the prime of life among seamen; while the whole were healthy. They were weighed as far as possible in the same clothes, and between 6 and 7 p.m., about two hours after a light “supper” of tea and biscuit, in order to reduce error from variations in the state of the bowels, stomach, bladder, &c., to a minimum. Their faulty diet, however, unmodified for temperature, and containing salt meat and other hurtful articles, was an unavoidable disadvantage. Fortunately this enables us to observe the effect of an agency far more under control for modification or removal than climate. Tape I.—To show the effect of Tropical Weather alone on the weight. Ist weighing, July 2, 1866, on entering tropics, ci Panties 18, 1866, on quitting tropics, j \ 108 days, all spent in the tropics. Average temperature at Sydney 60° F., at Cape York 82° F Food consumed per man daily. Salt meat issued on ...... 36 days Be © lb. oz. drs PGT Bec yaice: days) Average of first week ... 2 5 123 Fresh meat issued on...... Tae 55 Somes 7 Tastiq?; sn) oe Tota] | Number Number Range| Ave- Number Range| Ave- Age. | number ae ae of | rage oa of |r age ae percentage | percentage he percentage es a weighed. gain. | gain. : loss. | loss. 2 unchanged. |who gained, who lost. percent.) percent.) Ib. Ib. per cent.| Ib. Ib. 15 to 25 35. | 3= 857 | 13=3714 | 1-8 3 19=54:28 | 1-14 | 5-16 2D 4, 3D 39 ahah 8=20d1 | 2-10 | 3:37) 28=71°8 || 1-12.) 47 EOP ert — 00 0d ea eC 30 ,, 49 ial tains dees 2=22°22 | 1-2 45 ,, 55 2 So Oren ee aa Poe ola ea re OO aaa eeeaee 5 Totals 85 T= 8:24 | 23=27-06 | 1-10 | 3 5d=6471 | 1-17 | 5 and per- are a centages. 30=80'3 per cent. Table I. shows the effect of 33 months’ exposure to an average tempera- ture of 82° F. towards Torres Strait. Of 85 weighed, 644 per cent. had lost flesh to an average of 5lbs. Though greatest among the adults (>ts7 Ab (71 per cent.), and especially the higher ages (774 per cent.), it was large even among the juniors, of whom 54 per cent, instead of growing, lost con- 302 Dr. A. Rattray on the Effects of [Feb. 16, siderably. Lime-juice was given; but the 36 days of salt meat doubtless added to these results; and to make the experiment thoroughly satisfactory, fresh meat should alone be issued—almost an impossibility in the present transition state of naval dieting. Still the event is sufficiently decisive to prove the prejudicial influence of tropical climates on the physique, at all ages. Of 15 officers and men subsequently tested after 17 days more prolonged and direct solar exposure, but with a larger allowance of fresh (preserved) meat, 11 had lost from 1 to 9 lbs. (average 3,3-), 1 being un- changed, while 3 had gained. Of the latter, one was a black (and there- fore in his native climate), who increased 1 ib., the other two being healthy boys who gained 1 and 2 1b. respectively. This shows that the wasting effect of tropical weather in the adult white is not preventible even by a tudicious regimen. ; Tasiz I1.—To show the effect of Tropical Climate and Salt-meat Diet on the weight. Ist weighing, October 9, 1865, at Cape York, = 2 Sn Pa Qnd ,, November 6, 1865, at Cape York, +28 days, all spent in the tropies. Average temperature at Sydney 60° F., at Cape York 84° F. Salt meat issued on ...... 24 days VED BGT hs ag = a with 28 lime-juice days : ae ules Ly ey ay ys) Average of first week... 2 1 7 sesees ” 4 last i we 9 9 9 1 tS H Total cube SEs Range| Ave- a ‘Range| Ave- Ag 1umber ne. sa of | rage Le f | rag eS ‘ohed, | Percentage percentage z. ite percentage lo. ees wergnee. | unchanged. |who gained.| 88" | 89" |“ who lost. | “OSS: | +055: eres hss = : per cent.| percent.| lb. lb. per cent.| lb. lb. 15 to 33 3=9:09 | 6=18-18 | 1-10 24=72-°73 | 1-10 | 4 25 4 20 ,, 00 33 2=6°06 | 2= 606 | 1-4 2% |29—87-87 | 1-10| 6 30 ,, 40 tipo tad as re 1=143 6 AR Totals 76 5=658 | 9=11:84 | 1-10} 388)/62=81-58 | 1-i2 | 418 and per- ae oe a centages. 14=18-42 per cent. Table II., the results of another northward cruise, shows how much this loss of weight is increased when the diet is one of salt meat*. The season being the same (S8.E. monsoon), though the exposure was shorter by 80 days, no fewer than 81 per cent. lost to an average of 4lbs.—this, among the boys and youths, being larger than before, even though their food was increased ; which proves that a diet like this, not only highly salted but too nitrogenous for warm climates, adds materially to the injurious influence of tropical weather at all ages. After amore prolonged stay at Cape York (one year), eleven marines, fed on a mixed, fresh and salt-meat diet, had lost weight to the average extent of 11% lbs. * z.e, The ordinary sea dietary, in which 1 lb. of salt meat, beef and pork alter- nately, forms the chief part of the dinner, 4 >] | 1 : \ a} { ? ; 1871.] Change of Climate on the Human Economy. 303 Tass IlI.—To show the conjoint effect of Tropical Climate, Salt Meat, and hard Subsolar work on the weight. Ist weighing, June 2, 1864, on entering tropics, 1042 dacs 62 in the tropics, 2nd 5 September 14, 1864, on quitting tropics, Y8) 49 in temp. zone. Average temperature at Cape York 80° F. Food consumed per man daily. Salt meat issued on ...... 51 days (with 90 lime-juice days) juga ACHE CE HE Fresh meat issued on...... 53; ee: Berd Beh dab.” 1 ke Ae Sr OF Total Number | Number Betiae ll seeea Number Range| Ave- ihe and and = and ¢ ge. | number fi : of | rage oi | rage weiched, | Percentage | per centage Lae a percentage l es ene: unchanged.|who gained.) + | 8" | “who lost. | C88 | “O85 per cent.| per cent.| Ib. lb. per cent.| Ib. lb. 15 to 25| 63 2=3°18 =4:76 | 2-2 | 2 |58=92:06 | 1-24 | 6:34 29°95, 00{ 35 1=2°86 | 38=8867 | 48 | 5:33/31=88:°57 | 1-17 | 7-74 35 ,, 45 Biot > tspeagune ol eae eS ae ee ee 5=100 5-16 | 9:2 PD (ilcsyase | | senses ots | Sesslesiagt S/O Nimans eeaneee nto atitoh was VI cdalee's in tomer Totals | 103 o=2'91 | 6=582 | 2-8 | 3:66|94=91:26 | 1-24 | 6:96 and per- “sees SS SS centages. 9=8°74 per cent. | Table I1I., the record of another trip to Torres Strait, also during the S.E. monsoon, shows that the body is still further affected when a third injurious influence, viz. hard subsolar work, is added to these. ‘Thus, of 103 weighed, 1 per cent. lost flesh to an average of 7 lb. nearly; the number of boys and young men being large, because most employed, although the average individual loss was greatest among the seniors—thus 6 lb., 7 lb., and 9 lb. under 25, 35, and 45 respectively. This did not arise from a reduced diet; for the daily average consumption at the end of the period, when thus losing, had increased by 3% oz. per man. A contrast of Tables IV. and V. further shows that season materially influences this reduction in weight. Table IV. gives the results of 46 days during the cool dry S.E. monsoon (aver. temp. 82° F.), which lasts for 9 months; and Table V. of 54 days during the sultry rainy N.W. mon- soon (aver. temp. 87° F.), an exaggerated form of tropical weather related. to the other as are the winter and summer in temperate latitudes. While the number who lost flesh during the dry season was 44 per cent., it was 76 per cent. during the wet monsoon. The small per centage of gain even among the strong and vigorous juniors in the wet season, viz. 10 and 143 per cent., is worthy of contrast with that of the dry season, viz. 593 and 432 per cent., as it shows that even the healthiest age cannot long with- stand the emaciating influence of the worst season of the tropical year. The high average percentage of loss (7 lb.) and low percentage of gain, 24 lb., during the wet, contrasted with that of the dry monsoon (31b. and 4-">lb.), which equally affects all ages, further illustrates this. ‘The m- 304: Dr. A. Rattray on the Effects of [Feb. 16, creased ingesta towards the end of both experiments could not prevent these results; nor is the difference between the two seasons ascribable to a material dissimilarity in the quantity of the food. TasLe IV.—To show the effect of Season in the Tropics on weight. Cool and Dry. §8.H. Monsoon. Average tenperature at Cape York 82° F. Ist weighing, April 11, 1865, on entering tropics, waa 46 in the tropics, 2nd June 23, 1865, on quitting tropics, Y® | 27 in temperate zone. Salt meat issued on ...... 62 days. [ SUOOEL ECTS TENET. ee ib one (with 55 lime-jnice days) a la ena ie iT a Fresh meat issued on...... lk ae MERE EES 1 Bie pane s 5 QSt 44): aac Tene Total Number | Number Range| Ave- Number Range| Ave- Age. | number een aug rage aud of | rage ee eet tee percentage | percentage Sri percentage lage ‘ies ore unchanged. |who gained. gam. | &4™- | who lost. ; ; per cent.| per cent.| Ib. lb. per cent.) Ib. lb. 15 to 25 37 2=541 |22=—59:°5 | 1-12 | 436 |13=35:14] 1-9 | 261 25 ,, 35 32 1=313 | 14=43°75 | 2-14 | 5:36 |17=53-12 | 1-12 | 3-94 3D ,, 45 9 iheeate iI 3= 3:33 | 3-7 | 5 5= 555 | 1-9 | 38 49 ,, VO 1 1=100 eveccesvee {| seeeee | eesnee [| cosesesee | eeeeee | seeeeoe Totals 79 5=6°32 |39=49°37 | 1-14 | +77 | 35=44:30 | 1-12 | 3-15 and per- = ~- — centages. 44—55-69 per cent. TasLe V.—To show the effect of Season in the Tropics on weight. Wet and Sultry. N.W. Monsoon. Average temperature at Cape York 87° F. Ist weighing, November 25, 1864, on entering tropics, "6 days { 54 in the tropics, Aid ee February 9, 1865, on quitting tropics, (9 CAY® |) 22 in temp. zone. Salt meat issued on ...... 70 days ped ons ae deat iy (with 60 lime-juice days) pieeemene eon ae Fresh meat issued on...... Hee ? iL. last 5 Used gh ae Total | Number | Number |p... belAmes Number Range| Ave- Age. | number ane ae of | rage ae of | rage ge Sa percentage | percentage ; 8 percentage Taae oe Be! unchanged. |who gained.| 8° | 87 | who lost. ; per cent.} per cent.} Ib. lb. per cent.| Ib. lb. Isto 49 Oe 18=16-38 ||. 5 = 102 1-5 | 2:2 |36=73-47 | 1-16} 6 25 ,, 30} 34 2= 588 | 5=1471 | 1-8 | 34 |27=79-41 | 1-16) 8 39 ,, 45 9 sect gs Mi lla i i A a br ey 8=88'88 | 4-20 | 9 45 ,, 5d 1 1=100 eecedceeve§ =} ssadwe fF epnusece | - oe es eineisic.> Hip C46 @uiay 7h) eB woes Totals |) 93° 919-91 |10=10°46 | 428 tts See and per- 2 8) Se es 2 centages. 2=23°'65 per cent. 4) 1-20) 715 ey) Fei] Change of Climate on the Human Economy. 505 TaBLe VI.—To show the influence of Temperate Climates &c. on the weight. Ist weighing, September 14, 1864, near Sydney, 72 days, all spent in the aude", November 25, 1864, after leaving Sydney, temp. zone. Average temperature at Sydney 65° F. Food consumed per man daily. Salt meat issued on ...... do days i eid etna 20 Liane) tug Gays) Average of first week... 2 8 a4 Fresh meat issued on...... Giles i side oP tena 3 ‘raalae ae Total eee : ee Range| Ave- ee Range| Ave- Age. | number rev Of | stag rage ede) Pet centage | percentage Bo a percentage lag 1 ENC unchanged. |who gained. 8 gor | who lost, |b a0 eee per cent.| percent.) Ib. Ib. per cent.| Ib. ie 15 to 25; 48 d= OVen loo=oelead | 2-11°| 59) | 5=11-63) 1-643 25 ,, 835| 32 A= Do 2081-25") 2-14 165 |) 2S 6-25 e2-3) a 35 ,, 45 (S) ool aE rca i—6ho “WI-lo | FAs | T= 12 biel 1 PPM MRC ae | ssc ysccaa’. yh hascees et soteak | weasaes |i) arscucho co) sesuers | Meee Totals 83 T= 843) (688193) I=15)| 63) | S= 9:62 | 1-6) 2 62 and per- Ss Re ae centages. 75=90-36 per cent. Table VI., in strong contrast to the above, shows how much and rapidly the system rebounds under an opposite change of climate, and when re- moved from excessive warmth into a healthy temperate climate, with a fresh meat and vegetable diet, light work, frequent leave, &c. Thus after a 54 days’ stay at Sydney in spring, notwithstanding the debilitating effect of 35 salt meat days before and after the experiment, no fewer than 90 per cent. had either gained flesh or lost nothing, the average gain being large (6lbs.). In the 93 per cent. who lost, this was probably due, as it occurred among the juniors, to those excesses so common after long confinement on onal Thus, during the three years over which these triannual trips from Syd- ney to Cape York extended, the weight of the crew was continually oscil- lating, increasing at the former, and again decreasing on returning to the tropics. Frequent, sudden, and great changes of temperature and climate like this, are doubtless fertile causes in undermining the constitution and inducing premature old age. But for the re-invigorating influence of the periodic return to cool weather, many more would have succumbed to broken health. As it is, Table VII. shows that after 15 years 44 per cent. _ of those who originally went out in the ship had lost flesh, while other evi- dence showed that the health and strength of all had declined, there being moreover no proof of the occurrence in any of that doubtful event, accli- matization. The appetite and consumption of food had also diminished from the same cause. 306 Dy, A. Rattray on the Effects of [Feb. 16, Tasie VII.—To show the effect of a 14 year’s stay in a Tropico-temperate region on the weight (including 4 trips between Sydney and Cape York). 184 in the tropics, Ist weighing, August 10, 1864, near Cape York, x 2nd a 269 in temp. zone. 5 November 6, 1865, near Cape York, Food consumed per man daily. Salt meat issued on 229 days AoA Ib. oz. drs. with 154 lime-juice days x eee ee = : ys), 4 Average of first week... 2 8 7| 22 last; ee eas Total ea ee Range} Ave- ee Range| Ave- Age. | number oe a of rage oe of | rage eee percentage | percentage ata | aaa: percentage leas: eee eS unchanged. |who gained.| § 8 who lost. : ats per cent.| per cent.| lb. lb. per cent.} Ib. lb. 15 to 25 29 l= 345 |18=62-07 | 2-15 | G17 | 10=3448 | 2-14) 6 25 ,, 39 27 4=14:81 | 8=29-63 | 1-16 | 5:120/15=55:5d | 1-15 | 56 35 ,, 40 Dial Speeds 3=60 5-10 | 8 A=49 1-3 2 4D 43 DO raagued 01) Sawmeds ecb] o Gaadectes | A. bebe: ewantin Ti anime eee ne Totals 61 5= 819 |29=47-54 | 1-16 | 6:08 | 27=44:26 | 1-15 | 5-52 and per- = S See centages. 34=55'74 per cent. During the next eighteen months the crew had more fresh meat in the northward trips, the beneficial influence of which manifested itself by re- ducing the percentage of those who lost flesh to 283 (Table VIII.), as well as the percentage of loss. The appetite, however, remained much im- paired. Tazxe VIIL.—To show the effect of a 3 years’ stay in a Tropico-temperate region on the weight (including 8 trips between Sydney and Cape York). Ist weighing, August 10, 1864, near Cape York, 532 in the tropics, 11141 days { 2nd .° 4, September 25, 1867, near Cape York, } 609 in temp. zone. Salt meat issued on ...... 575 days STONES ae tb aoa a (with 540 lime-juice days) Pn ae ee 9.8 41 Fresh meat issued on ... 566 ita cir Sd re 827 | mn last ,, WIV AGF VE a Total ee , Pole Range| Ave- pee Range| Ave- Age. | number of | rage oe of | rage = weighed. percentage percentage ati Bath, percentage l l | u nchanged, who gained.) 8¥™ | & who lost. |) per cent.| percent.| Ib. lb. per cent.| Ib. lb. 15 to 25) 25 ere 19-67. 3-40 | 14°68 | 5=20 3-12 | 5-2 20.4,°9 15 1= 6°66 | 8=53:33 | 1-18 | 7:125| 6=40 1-15 | 6:16 30 ,, 40 2 BSSOO ray Vad wg ly Saas) ras ae 1=50 0-1 | 1 A OA b ieenaee, | | terperdee y | jcoaswansss) |p geaNepipll sedace, |. .2sasceeegl Totals 42 | 8= 714 (27=6429 | 1-40 |12°5 | 12=28-57 | 1-15 | 542 and per- re 5 a | centages. 30=71°43 per cent. A similar slowly progressive impairment of the physique also occurs during long sea voyages, in which ships pass repeatedly and suddenly from cold or temperate to tropical latitudes, and the reverse. 1871.] Change of Climate on the Human Economy. 307 Tasie 1X.—To show the effect of a long voyage of 55 days (including Tropical Weather and Salt Meat) on the weight. Average temperature, England 50° F., Equator 88° F., South Atlantic 72° F. Ist weighing, January 9, 1864, England, Be dave 34 in the tropics, Qnd ,, March 4, 1864, South Atlantic, Y°'| 21 in temp. zone. Food consumed per man daily. Be f : Ib. ES 1 Average of first week... 1 12 133 Leva eae shie | ce See Salt meat issued on ...... (with 11 lime-juice days) Fresh meat issued on...... O45 Total Number Number Range| Ave- | Number ne ibe and and oor ae and ¢ ue Gs 1 eeareene percentage | percentage at mae ‘centage | ,° ase eighed. Bee ain. | gain. | P&vCPNtS° | joss. | loss. eae) unchanged. who gained. 6 g who lost. per Gent.) per cent:|.. Ib. lb. per cent.| lb. lb. 15 to 25 80 c=) 20=31-25 | I-11 | 3:84 |51=63°75 | 1-23 | 6°72 25 ,, 30 45 3=666 | 138=28°83 | 1-13 | 377 | 29=64-44 | 1-20 | 7-41 Bo ,, 40 Hea food |ihinaptng Da 3=23:07 | 47 | 5 10=76°91 | 1-19 | 63 EME TR ON | rd Sedat Mh arated | aadisslgn|iaeeedes’( is vdadaaaat, (sso eny a olhpemmeee Totals 138 ras 07 | 41= sles Spy | 1-13 | 39 |90=65:22 | 1-23 | 6°93 and per- = centages. 48=3478 8 per cent, | Thus Table IX. shows that after a 55 days’ passage from the cool climate of England across the equator to the south temperate zone, 65 per cent. of the crew had lost flesh to an average of 7 1b. nearly—the juniors suffering, though not so much as the seniors. An increased sick- list at the close corresponds to this. These results were not due to a decrease in the ingesta, as the daily consumption during the last averaged 6 oz. more than during the first week. The cause was therefore partly climatic and partly dietetic, salt meat being issued most of the time. TABLE X.—To show the effect of a long voyage in the Temperate Zone, but on Salt Meat, on the weight. Average temperature, Cape of Good Hope 65° F’., Sydney 62° F. 1st weighing, April 19, 1864, Cape of Good Hope, | 49 days, all spent in the temp. 2nd June 2, 1864, near Sydney, zone. Salt meat issued on ...... 48 days RODIN g rae Se ith 39 lime-juice days) tae ete ime | y Average of first week 2 De Fresh meat issued-on...... I day task Seekekae 5 Le bh) yu $9 eon hed e 3 Total Number | Number Number Range| Ave- Range| Ave- ee ee ec cee or rape Bees Ct ee aoe unchanged.|who gained. BALD BALES. liriin Haste | Loess percent.) percent.) Ib. lb. per cent.| lb. Ib. 15 to 25) 77 8= 1039" 60=7792} t= 4-78 | 9=11-61 | 1-4 )-24 25, 00, 4 4= 9-75 |22=53'66 | 1-19 | 5°54 | 15=36°60 | 1-9 | 3°66 BD ,, 40 14 3=21-43 | 9=64380 | 2-8 | 5 2=14:30 | 1-2°>| bo Eagan, a mene Waconia eee gene ie (lt. cgesqaees [ seepenl ty eaeames Totals 132 15=11°36 1= 69°69 | 1-19 | 5 26=19:69 | 1-9 | 2:58 and per- Ms aa centages. 106=80'30 per cent. | 308 Dr. A. Rattray on the Effects of [ Feb. is; Very different was the effect of the 44 days’ continuation of the voyage to Sydney along the 40th parallel of south latitude, after a health-infusing stay of fifteen days at Simons Bay (Table X.). Although the usual sea dietary was continued, the exit from the tropics was an evident relief to the system, which, but for the diet, would have retained its vigour throughout. As it was, only 26, =19°69 per cent., lost flesh slightly. All the boys, whohad the strong vital resilience of youth in their favour, gained in weight, and also the younger men, while the seniors lost. An increase in the ingesta of 7 drams daily towards the end of the period is too trivial to have influenced these results. This shows how long the system will ward off the scorbutic diathesis when opposed by no other serious adverse agency, provided lime- juice is given as a prophylactic. The increased sick-list and intensity of the ailments, however, towards the end of the period, show that the immu- nity was passing off. The difference in the percentage of those who lost flesh in this and the former part of the voyage (Table IX.), is evidently the effect of climate, and indirectly confirms Tables I. and I. To the bracing effect of the S. temperate zone we must chiefly ascribe the recovery of the crew. Wasted while crossing the equator, only 29 per cent. were below their original weight in England on arrival at Sydney. This loss, though evident among the juniors, was chiefly among the adults and older men (Table XI.). The superior health and efficiency of a crew in cool climates is an evident indication in planning long voyages. And we have only to recollect the position and direction of the chief winds and ocean-currents usually followed, to see how much these favour the mainte- nance of health as well as rapidity of progress. TasLe XI.—To show the effect of a voyage of 144 days on the weight. Average temperature in England 50° F., Equator 88° F., Sydney 62° F. Ist weighing, January 9, 1864, in aes 144 days 27 in the tropics, 2nd % June 2, 1864, near Sydney, 117 in temp. zone. Salt meat issued on ...... 110 days ODE ELASTINGE! yes scr bee pope 0 mene days) Average of first week .... 1 12 13% Fresh meat issued on ... 34 ,, 8 sass pia - last. 5, se0n ee Total hae eee ce Range| Ave- eee Range| Ave- Age. | number an t of rage E i t rage ‘shed, | Percentage | percentage Paiieaatn. percentage | 10.5 | loss ee unchanged. |who gained. who lost. ; per cent.| per cent.| Ib. lb. per cent.| Ib. lb. 15 to 25 76 5=6°58 |52=—68°42 | 1-18 | 5-73 | 19=25 1-25 | 5-47 25 ,, oo 42 38=714 | 25=59°52 | 1-15 | 5°76 | 14=33°33 | 1-15 | 5°85 35 ,, 45 12 1=8'33 6=50 3-7 | 5 5=41°66 | 1-14 | 7-2 Bip Ve PARP cabelas ce 2]. Seaannes (el ldapaniell: 42 cteehe celles aie ae el er Totals 130 9=6°92 |83=63°85 | 1-18 | 569 | 38=29-23 | 1-25 | 584 and per- SS ~ = centages. 92=70°77 per cent. 1871.] Change of Climate on the Human Economy. 309 The passage to Cape York, however, again increased the general sym- ptoms of an impaired physique (Table XII.), thus proving the existence of a constant ebb and flow in the state of health during long voyages. TaBLe XII.—To show the effect of a voyage of 230 days on the weight. Average temperature, England 50° F., Equator 88° F., Sydney 62° F., Cape York 80° F. Ist weighing, January 9, 1864, England, 95 _ f 90 in the tropies, 2nd_~=sg,_~S ss August 10, 1864, Cape York, i eel US {180 in temp. zone. Food consumed per man daily. Salt meat issued on ...... 156 days ae oe cee pies 4 Average of first week... 1 12 133 ee 2 5 dust) 3, me ee Orewa + = | Total - oo - satay Range| Ave- ae Range| Ave- Age. ae 4 percentage | percentage = wee percentage a et weignec’-|unchanged.|who gained.| 89> | 87+ | who lost. | “O88: | *O5S- per cent.| percent.| Ib. lb. | per cent.} Ib. lb. 15 to 25| 61 T=11-48 |18=29°51 | 1-19 | 7-11 |386=59-01 | 1-32 | 6-1 29 ,, 30 3D 1=2-86 8=22°86 | 1-16 | £87 |26=7428 | 1-22 | 654 39 ,, 49 eee ake nnn: 2=14-29 | 1-2 | 15 5=71-45 | 6-23 | 138 eR MENOa A ore al eee ci htc Naz. sip) eG ee ee Totals | 1035 =(77 |28=27-18 | 1-19 | 5:36 |67=65-05 | 1-82 | 6-83 and per- _ ae eee ee centages. 36 =35 per cent. Thus, though 55 days in all were spent at Madeira, Simons Bay, Sydney, and Brisbane, on a health-giving fresh meat and vegetable diet (see Table VI), and lime-juice freely given, the monotony and confinement of 175 days at sea, with 156 salt-meat days, a double exposure to the tropics, and fre- quent changes of temperature, had increased the number who had lost weight since leaving England to 65 per cent.—a decided index of failing health and near approach to disease, and perhaps the scorbutic climax. Similar fluctuations in weight, subsequently observed in the larger crew of H.M.S. ‘ Bristol’ during a voyage of 88 days from England to Bahia (lat. 11° S.) and back, are equally interesting and instructive (Table XIII). Thus the warm weather and salt-meat diet of the first 57 days caused 85 per cent. to lose weight, which rose to 88 per cent. as the time lengthened to 88 days. The return to the north temperate zone, however, speedily reduced this to 47 per cent. As the diet was the same, the latter event must have been purely climatic—an opinion confirmed by the subsequent effect of 28 days’ harbour-life in England, when the number who lost went down to 10°7 per cent., no fewer than 89 per cent. regaining flesh and more than making up for the previous loss. 310 Dr. A. Rattray on the Effects of [Feb. 16, TapiEe XIil.—To show the effect of climate and diet on the weight of an adult crew, June 18 to September 14, 1869. Average temperature, England 60° F., Equator 77° F., Bahia 76° F'.; England (return) 60° FB. Number Total ae Range} Ave- — Range} Ave- Remarks. sass abo einer | es mg ge percentage ae toe not lose. . per cent.| Ib. Ib. per cent.| Ib. Ib. Effect of first 57 days ...... 425 | 64=15:06 | 1-15 | 2:58 | 361=84-04 | 1-28 | 5-75 each 45 in the tropics OF ware’ | 88 on salt meat. Effect of first 88 days ...... 296 36=12:18 | 4-13 | 3:5 | 260=87-84 | 1-30 | 5-47 Pshiok 66 in the tropics or wate | 61 on salt meat. Effect of last 31 days ...... 310 | 164=52:93 | 4-9 | 2-64 | 146=47-1 | 3-10 | 2-81 21 in the tropics 10 on salt meat. Subsequent effect of 28 days} 391 |349=89-26 | 1-19 | 4°70 | 42=10-74 | 1-9 | 2°66 in harbour (England) on fresh meat and vegetables. of which Table XIV. shows that, while the same prevailed among the ship’s boys (age 17 to 20) and naval cadets (age 14 to 17), youth and lighter work &c., have an evident effect in lessening the percentage of loss under such adverse agencies, and increasing the gain under opposite conditions. Taste XIV.—To contrast the variations in weight, during long voyages, of the men, boys, and naval cadets, June 18 to September 14, 1869. Average temperature, England 60° F., Equator 77° F., England (return) 60° F. Number and England to Bahia (lat. 11° 8.), aoe percentage who Number and : number ee: ai percentage 8 days. er gained or did weighed. aiid who lost. per cent. er cent. Effect of first 57 days ............ Men 425 34 15:06 561=84:94 Late nl 45 in the tropics, Boys 64 28= 43-74 36=56:25 38 on salt meat. Cadets 60 23= 38:33 37=58'33 Kffect of first 88 days ............ Men 296 a6 127716 260=87°84 : 66 in the tropics, Boys 40 16= 35 24—60 of which Bt 03 : iS SAL? phan agin ae on salt meat. Cadets 58 20= 34-47 38=65'51 Effect of last 31 days ............ Men 310 | 164= 52°93 146=47'1 of which { 2! in the tropics, Boys 41 380= 73°17 11=26°82 10 on salt meat. Cadets 59 34= 57°62 25= 42°37 Subsequent effect of 28 daysin} Men 3891 | 349= 89:26 42=10°74 harbour (England) on fresh} Boys 34 30= 90:58 4—11-76 meat and vegetables. Cadets 28 28= 100 871.} Change of Climate on the Human Economy. 311 Thus 85 per cent. of the men lost flesh during the first 57 days, but only 56 per cent. of the boys, and 58 per cent. of the cadets. Again, during the first S88 days the percentages were—men 88, boys 60, cadets 65. Further, while 53 per cent. of the men began to recover weight on reenter- ing cool weather, 73 per cent. of the boys and 58 per cent. of the cadets did the same. Lastly, in England, while 89 per cent. of the men gained, among the boys we find 904 per cent., and among the cadets 100 per cent, The advanced age, greater strength, and rougher eatly life of the boys enabled them to bear the voyage better, and recover sooner under genial agencies than the younger delicately-reared cadets. On the other hand, a generous diet and better regulated life caused the latter to increase more in England. Under favourable conditions, as to climate, diet, &c., the weight of men, and particularly boys, should not fluctuate thus. Nor can such changes be salutary. As arule adults, with fully developed frames, should remain pretty stationary in weight. Boys, however, should increase not only in weight, but in height and breadth of chest. For the former to emaciate, or the latter to grow taller and broader, while the weight remains the same or lessens, is a sure sign of present or impending mis- chief. The average of 13 1b. per week by which these cadets increased at home, may be considered the healthy rate of growth for boys of their age. And we may give Table XV. to show the effect of subsequent longer leave in England on the physique of a larger number of cadets. TapLe XV.—To show the effect of a healthy diet and climate on the physique of naval cadets, age from 14 to 17 (September and October 1870; time 44 days; temperature 64° F.). Number | Number Number Total and and Range| Ave- and Range| Ave- oe of | rage of | rage neers el P ed pain. | gain. pes ste loss. | loss. per cent.| percent.| Ib. lb. per cent.! Ib. Ib. Weight.| 52 1= 1:925)48=92°31 | 1-20 | 5°93 | 8=5°77 1-2 | 1°66 Hae TO ees in. Height..| 54 20 =387-04 | 34=63 Feo POO erty tree RES, eorgee Chest ... Oye DN ASME sea ualeaer ey Saw Cha een eee alg EC eee Thus, of 52 cadets, 93 per cent. either did not lose or gained flesh to the average of 1 lb. per week, while 63 per cent. increased in height, and no doubt in capacity of chest ; but the time was too short to obtain satisfac- tory results as to this. Obviously, therefore, if cadets are long subjected to influences which retard their growth, even if disease does not ensue, their future strength, both of body and brain, is apt to be impaired ; while ship’s boys and young seamen are not likely to become physical athletes, nor adults to retain their vigour as fighting men. These conclusions neces- sarily apply to all similarly situated. 312 Dr. A. Rattray on the Effects of [Feb. 16, If we can isolate the effects of tropical weather so as to contrast them with those of other health-impairing agencies, it will be both interesting and practically useful. ‘Table XVI. shows when we find the greatest gain or greatest loss of weight. Life under the healthiest conditions, in which the highest gain (903 per cent.) and lowest loss (94 per cent.) occurs, is first given as a standard for comparison and index of what should be aimed at in all latitudes and circumstances. _ Taste XVI.—To compare the effect of climate and other agencies on | the weight. Gain or unchanged Loss Reference. | Pernicious influences. | Per | Ave- | Per | Ave- cent. | rage. | cent. | rage. glihesa Ib. Ib. Mable Vai. WNome scccstecen acetone teecnee erences 90-36 | 6°3 9-64 | 2°62 5s eg? | Omes(Galtaniedt) wc. tsonk.wanoteasyoaers S105, > 19-69 | 2°58 aed ek One (tropical climate) .............4- 35°30 | 3 64:71 | 5 », LX. | Two (tropical climate, dry season, | 34°78 | 3°9 | 65:22 | 6:39 and salt meat). » V. | Iwo (tropical climate, wet season, | 23-66 | 2:8 | 76°34 | 7-15 and salt meat). III. | Three (tropical climate, salt meat,| 8°73 | 5°66 | 91:26 | 6:96 and hard work). 39 We here notice a progressive decrease in the number who gain or do not lose in weight, and necessarily a corresponding increase’ in the percentage of those who lose, according to the variety and intensity of the adverse agencies. Thus fewest emaciate when the influences are altogether genial, viz. 9°64 per cent. An injurious diet raises this to 19°69 percent. Under tropical climate it rises to 64°71. Under the latter and salt meat combined, it again rises to 65°22 per cent., and in the rainy season to 76°34 per cent. When, besides this, hard work is undergone, it mounts to 91°26 per cent. The average gain and loss columns show a similar though less regular in- crease and decrease. ‘Tropical climate is thus by far the most injurious influence; and its effects are materially aggravated by other adverse agencies. [And the Tables show that these facts apply to the junior as well as the senior ages, though occasionally more apparent in the latter—Feb. 27. ] We must know the nature of these universal and marked changes in the weight, and the tissues involved, before we can decide whether they are physiological or pathological, and, if the latter, satisfactorily direct our hygienic or therapeutic efforts to prevent or remedy them. We cannot ascertain by anatomical or histological investigation ; but we may fairly suppose that every or nearly every tissue is more or less implicated—those 1871.] Change of Climate on the Human Economy. 313. which carry on the functions of animal life being most affected, especially such as form the great bulk of the body. It would be difficult to say whether the watery part of the blood and body generally is reduced by ex- cessive perspiration. The osseous system and thoracic and abdominal viscera are probably little changed. The fibrous and gelatinous are perhaps more altered ; but it wouid be difficult to separate this from the change in the fatty muscular and nervous tissues, the three doubtless most of all affected. In warm latitudes less fat is required than in cold ones to keep out cold and generate internal heat or muscular force. Hence nature uses it up in its vital processes, and thus first gets rid of what does not itself play a vital part in the human economy, or materially influence health by its removal,. and would only prove an encumbrance. The prevalent languor of body and mind no doubt arise partly from diminished energy im the nervous and muscular tissues; but are they not also, and perhaps principally, due to a decrease in their bulk, similar to that in other tissues? Strength is the manifestation of muscle acted on by nervous influence; and, from several experiments made on the officers and crew of H.M.S. ‘Bristol,’ strength decreases and increases with the foregoing changes in weight—a fact which goes far to prove that though loss of strength may be partly of nervous origin, the muscular tissue is also largely involved in its production, and is probably both physiologically weakened and physically altered in. Pp ¥ pay gically pay ¥ texture*. : : The cause of this reduction in weight in the tropics is threefold :—first, a diminished necessity for surplus fat, which becomes absorbed ; second, that peculiar and not easily explained physiological effect of heat, which causes the tissues to decay faster than in cold latitudes ; third, diminished lung-work and blood-oxygenation, and thereby animperfect renewal of tissue. On the other hand, the languor and weakness are due, first, to loss and relaxation of the muscular substance; second, to a similar loss of nervous tone and matter; third, to suboxidation of the blood}, which impairs the activity not only of the muscles, but of the nerve-centres which originate, and nerve-cords which transmit motor and sensory impressions ; [and, fourthly, in their early stage, to a reduced supply of their vital stimu- lant the blood, diverted from the internally situated nerve centres, nerves, and muscles, to the cutaneous surface.—Feb. 27.] The early and primary results of tropical warmth on the tissues are probably chiefly physical and quantitative ; but when prolonged, especially if conjoined with an erroneous diet, their composition is affected, and they are also chemical and qualitative. - What are the true bearings and diagnostic value of this closely-allied loss of weight and strength? Are they solely physiological? or when do they become pathological? Do they always, or at what stage do they indicate * These data were scarcely ample enough for tabulation. The ship’s motion, imper- fect testing apparatus, and difficulty of finding one equally suited for all men, in whom the best-developed sets of muscles often differ, make this a troublesome inquiry. + Proceedings of the Royal Society for_1870, No. 122, p. 520. VOL. XIX. 2B 314 Dr. A. Rattray on the Effects of [Feb. 16, a loss of vitality or health? If decreased weight originates merely in an absorption of fatty tissue, and no strength is lost, the result is at least not unhealthy. But when other tissues are involved (and it would be difficult to decide when they are, as this doubtless varies even in the same individual), it is then, if not disease, closely allied to it—and certainly an indication of an impaired and debilitated physique, prone to succumb to other morbific agencies, and ultimately to induce premature decay and old age. Physio- logical in their earlier stage, they soon become of doubtful nature, and finally decidedly pathological. And that there is a special and not merely a general relation between these phenomena and the health appears, first, from the results being so marked, uniform, and generally prevalent ; second, from concurrent indications of debility, shown by a progressive increase in the amount and severity of sickness; and, third, by a marked decrease in the loss of weight and strength in the tropics, when some of the agencies which indirectly augment its influence are removed, as will be proved by the following Table, which shows the effect of an improved diet. During a similar voyage from England to the South Atlantic, in two of Her Majesty’s ships, both crews were subjected to a corresponding amount of tropical weather ; but the number of salt-meat days in H.M.S. ‘ Bristol’ was twelve fewer than in H.M.S. ‘Salamander’ *, the result being that in the former the number of those who lost flesh and strength was reduced by 22 per cent. 3 Tas_E XVII.—To contrast the results of two similar voyages on the weight. : | Total pa puta bet Range| Ave- Nee Range! Ave- sales ‘ iontitilns se ennties of nape percentage f | ee unchanged. |who gained.| &9""- | 8°" | who lost. HAE long ey Perea per cent.) per cent.| Ib. Ib. per cent.| lb. Ib. 34 in the tropics |] . : bates : as ; 3D days | 38 Pe eas \ 379 =| 42=11-08 |172=45°38| 1-12 | 2°73 |165=43:53/ 1-13 | 2-45 H.M.S. ‘ Salamander.’ a 34 in the tropics : if . _@r. : ja days diy tui roe \ 116 | 7= 6-03 | 383=28-45| 1-13 | 418 | 76=65-52| 1-23 | 7-2 [This was equally apparent among the cadets (Table XVIII.). Thus, of 58, the number who lost weight became reduced from 653 to 40 per cent. by a removal from the tropics, combined with a limited use of salt meat. The improvement in their growth, as shown by their height and measure- ment of chest, was equally obvious. * From a lately introduced issue of preserved meat every third day in the naval dietary. 1871.] Change of Climate on the Human Economy. 315 Taste XVIII.—To contrast the results of two voyages on the weight of Cadets. Number and per- centage who gain- ed or did not lose.|. Number weighed. Number and per- centage who lost. a es i i | per cent. per cent. A voyage to Bahia of 88 days :— in tropics, 66 days... Ns on salt meat, 51 ,, ... } 58 20 = 34:47 38=65°51 A voyage to the Mediterranean of 100 days :— in tropics, 0 days i 7 Tr 34= 59-64 on salt meat, 5 ,, 23=40°35 The general loss of flesh (in other words, absorption of internal tissue) which results from the salt-meat dietary of long voyages, and which is here seen to be so greatly intensified in and by tropical climate, is really the essence and primary stage of scurvy, and corresponds in principle and nature with the visible, external, and superficial breaking down and loss of substance in the phlegmous abscesses, ulcers, &c., still too prevalent in the service, and in its more serious and advanced forms of the dysentery, and putrid ulcer, once so common and fatal; while the intensity, obstinacy, and sometimes the origin of many other local and general diseases frequent among seamen, e. g. rheumatism, syphilis, struma, various fevers, con- tinued, contagious and periodic, &c., have doubtless an equally close alliance.—Feb. 27. | These experiments were carried out in super-oceanic climates. It would be interesting to know how the weight and strength are affected in conti- nental ones, where the range of temperature and humidity &c. are greater, ‘as, for example, when troops are moved from the cool hilly regions of India to its sultry lowlands. These facts suggest important hygienic and therapeutic indications ; for example :— First. That the tropics, especially during the rainy season, should be avoided by natives of colder latitudes. Second. That the young, the debilitated, and the diseased should espe- cially shun warm regions. Third. That none but full-grown healthy adults should go there. Fourth. That with all, even the latter, a speedy exit should be made therefrom, when great loss of flesh and strength give warning of approach- Ing disease. Fifth. That such injurious agencies as may increase the weakening or disease-inducing influences of tropical climates, of themselves irremediable, should be avoided, e. g. faulty diet, over fatigue, impure air, &c. Sixth. That, to preserve health, a tropical climate should be frequently changed for the more temperate ones of higher altitudes or latitudes. 2B2 316 Dr. A. Rattray on Change of Climate. [Feb. 16, VI. Conclusion. The ultimate object of these varied functional and organic changes induced in the human frame by change of climate, is to accommodate it to altered meteorological and other conditions, and assimilate it to those of native races. It is the ease or difficulty with which different varieties of mankind, ages, sexes, and idiosyncrasies become accustomed to this that indicates their capability for what we term acclimatization. [Would not a more intimate acquaintance than we yet possess with the differences in the minute anatomy and functions of the various tissues and organs of these different races and families, and also their correlation and capability or not of assimilation under change of climate, go far to decide the long- vexed questions as to the unity or plurality of species and of creative centres ? —Feb. 27.] In these important changes, moreover, especially that in the current of the blood from the interior to the surfaceof the body on proceeding to the tropics, there is an evident analogy with certain great operations which take place under similar circumstances in the inorganic world. The air and ocean likewise heat as they proceed towards the equator, and finally overflow to form those beneficent winds and sea-currents which play so important a part in the economy of the globe, and influence its hygiene, therapeutics, and etiology, not less than its commerce. And although in these it acts on what may be termed the centre of their circulation, whereas in the human frame it operates on its periphery, the agent in all three is the same, viz. the sun’s heat, as is the primary effect, viz. a change in the direction of original currents, as well as the final results, viz. purification and modification of temperature. The general physical and general hygienic and curative schemes of nature are thus evidently connected. Without these pheno- mena the heat of tropical lands and seas, and cold of other regions, would be intolerable, and that of the skin and body too high or too low for the main- tenance of their vitality ; while both the air, ocean, and blood would rapidly become impure and unfit to sustain life. Deriving its first and chief impulse from the heart, the blood merely undergoes redistribution—the current in cold and temperate climates being directed towards internal, and in the tropics towards external organs, espe- cially the skin. In either case it flows from cooler towards more highly heated regions. Is not this vital process, therefore, in this respect also, at least partly akin to the allied phenomena in the air and ocean, and physical as well as physiological? The blood generally being probably somewhat warmer in the tropics than elsewhere, does not the heating of the surface and contents of the turgid cutaneous capillaries act as a vis @ fronte in in- ducing it to flow towards and accumulate here, as the warm interior does in cold regions ? 1871.] Dr. W. Huggins on a Registering Spectroscope. 317 IL “Ona Registering Spectroscope.” By Wiit1am Hveerns, LL.D., D.C.L., F.R.S. Received January 14, 1870. The short duration of the totality of the solar eclipse of December last, led me to seek some method by which the positions of lines observed in the spectrum of the corona might be instantly registered without removing the eye from the instrument, so as to avoid the loss of time and fatigue to the eye of reading a micrometer-head, or the distraction of the attention and other inconveniences of an illuminated scale. After consultation with the optician Mr. Grubb, it seemed that this object could be satisfactorily accomplished by fixing in the eyepiece of the spectroscope a pointer which could be moved along the spectrum by a quick-motion screw, together with some arrangement by which the position of this pointer, when brought into coincidence with a line, could be instantly registered. 3 I was furnished by Mr. Grubb with an instrument fulfilling these con- ditions, and also with a similar instrument with some modifications by Mr. Ladd, in time for the observation of the eclipse. Unfortunately at my station at Oran, heavy clouds at the time of totality prevented their use on the corona; but they were found so convenient for the rapid registration of spectra, that it appears probable that similar in- struments may be of service for other spectrum-observations. In these instruments the small telescope of the spectroscope is fixed, and at its focus is a pointer which can be brought rapidly upon any part of the spectrum by a screw-head outside the telescope. The spectrum and pointer are viewed by a positive eyepiece which slides in front of the tele- scope, so that the part of the spectrum under observation can always be brought to the middle of the field of view. The arm carrying the pointer is connected by a lever with a second arm, to the end of which are attached two needles, so that these move over about two inches when the pointer is made to traverse the spectrum from the red to the violet. Under the ex- tremity of the arm fitted with the needles is a frame containing a card, firmly held in it by two pins which pierce the card. This frame containing the card can be moved forward so as to bring in succession five different portions of the card under the points of the needles; on each of these portions of the card a spectrum can be registered. The mode of using the instrument is obvious. By means of the screw- head at the side of the telescope, the pointer can be brought into coin- cidence with a line; a finger of the other hand is then pressed upon one of the needles at the end of the arm which traverses the card, and the position of the line is instantly recorded by a minute prick on the card. A bright line is distinguished from a dark line by pressing the finger on both needles, by which a second prick is made, immediately below the other. In all cases the position of the line is registered by the same needle, the second needle being used to denote that the line recorded is a bright. one. 318 Mr. A. H. Garrod on the relation of the Cardiograph [Feb. 23, It was found that from ten to twelve Fraunhofer lines could be regis- tered in about 15 seconds, and that, when the same lines were recorded five times in succession on the same card, no sensible difference of position could be detected between the pricks registering the same line in ee several spectra. It is obvious that, by registering the spectra of difecue substances on the card, a ready method is obtained of comparing the relative positions of the lines of their spectra. Each spectroscope was furnished with a compound prism, which was made by Mr. Grubb, and gave a dispersion equal to about two prisms of as glass with a refracting angle of 60°. Postscript.—I have just learned that in a spectroscope contrived by Professor Winlock for observing the eclipse of December 22, 1870, the positions of the observing-telescope are registered by marks made upon a plate of silvered copper.—February 3, 1870. | February 23, 1871. WILLIAM SPOTTISWOODE, M.A., Treasurer and Vice-President, ‘in-the Grin The following communications were read :-— I. “On the Mutual Relations of the Apex Cardiograph and the Radial Sphygmograph Trace.” By A. H. Garrop, of St. John’s College, Cambridge. Communicated by Dr.Garrop. Received January 18, 1871. A desire to acquire an accurate knowledge of the relation borne by the commencing contraction of the heart to the origin of the primary rise in the pulse at the wrist, led the author to construct an instrument which has enabled him to determine, with considerable accuracy, the mutual relation of these two points, and to demonstrate one or two unexpected results, not altogether without interest. The cardio-sphygmograph above mentioned consists of a piece of board, 10 inches long by 53 inches broad, and about half an inch thick, along one side of which a sphygmograph can be laid, as shown in fig. 1. On the opposite side a spring (a) like that employed in the sphygmograph is attached to a moveable support (0), so that its tension can be modified. To the free end of the spring a small pad (c) is fixed, which is in com- munication with the cardiograph apparatus by means of a silk thread (d). This latter instrument consists of a light lever (e), a little over 2 inches long, connected to the board first mentioned by a frame (f) which is just free from the sphygmograph when the latter is in position. The lever, which is one of the third system, is connected on either side, close to its 1871.] and Radial Sphygmograph Trace. 319 fixed end, to two silk threads, one of which (d) is attached to the pad and spring above mentioned, and the other to a small spring (g) which moves. it when it is less acted on by the stronger spring. The apparatus is so arranged that the lever works perfectly when it is so placed as to be above the registering part of the sphygmograph, when the latter is in position. The tip of the lever carries a steel pen (4). Fig. 1. To use the instrument, the See is first fixed on the left arm as usual, the recording paper being adjusted to its place. The arm is then moved until the attached instrument rests on the board first mentioned ; and it is maintained in position by certain pegs and holes in the board, which respectively come into contact with the main parts, and receive the projections of the instrument. The arm and attached apparatus are then moved until the pad of the cardiograph spring is brought into contact with the spot, between the fifth and sixth ribs, at which the heart’s pulsation is most marked—the position of the pad in relation to the board having been previously so fixed as to enable this to be done with facility, the whole being maintained in the horizontal position. The contact of the pad with the chest-wall causes the lever to recede ; and it is allowed to do so until its pen arrives above the recording-paper, the whole apparatus being steadied by the right hand. When the levers of the two instruments are both found to be moving freely, the watchwork of the sphygmograph is set in action by means of a string, connected at the other end with the stop-block of the train of wheels ; and when the recording-paper has run its length, a combined trace is found, as in figure 2. The sontinercenient of he os aes is oe defined with precision; 320 Mr, A. H. Garrod on the relation of the Cardiograph (Feb. 23, and as they are both recorded on the same paper, synchronous movements must be at equal distances from the starting-points, and therefore they can be projected on one another. The results obtained by these pas form the subject of this communication. All the observations were made on the same anbjeet cetat. 04, in good health. They were all made in the sitting posture, as the apparatus could then be held more firmly, or rested on the arm of a chair. To facilitate description, the following terms and symbols will be em- ployed with regard to pulse-traces. 1. The rapidity of the pulse is symbolically represented by x. 2. The first cardiac interval is that which occurs between the commence- ment of the systolic rise and the point of closure of the aortic valve, in cardiograph traces. The number of times that this interval is contained in its component beat is represented by y; and the law as to its length, published elsewhere *, will be assumed; it may be stated thus : ay=20% x. 3. The first arterial interval is that which occurs between the com- mencement of the primary rise and the termination of the major fall in arterial sphygmograph traces. The number of times that this interval is contained in its component beat is represented by y'; and the law as to its length at the radial artery, which is alone considered in this communica- tion, published in the Proceedings of the Royal povicty (No. 120, 187 9), will be assumed ; it may be thus stated : ay! =47 X/ x. 4. The first cardio-arterial interval is that which occurs between the commencement of the systolic rise in the cardiograph trace and the origin of the main rise in the sphygmograph trace. The number of times that this interval is contained in its component beat is represented by z. 5. The conjugate cardio-arterial interval is that portion of the first cardiac interval which is synchronous with a portion of the first arterial interval. It is therefore the interval between the commencing sphyg- mograph rise and the point of closure of the aortic valve as represented in the cardiograph trace. 6. The second cardio-arterial interval is that which occurs between the point of closure of the aortic valve and ity indication at the artery under consideration. In commencing to work with the cardio-sphygmograph, measurements were made to find the duration of the first cardio-arterial interval, as it: required but a few experiments to prove that the heart commences to contract before the pulse is indicated at the wrist. - By means of compasses, or by superposing one trace on the other, the commencing cardiograph rise was projected on the sphygmograph trace ; and the interval between this event and the origin of the radial rise was * Journal of Anatomy and Physiology. Cambridge, vol. v. Noy. 1870. 1871.] and Radial Sphygmograph Trace. 321 then measured into its component beat in each pulsation of the trace, from which the average of the observation was obtained. The results are given in Table I. Column II. ; and in Column III. some of these are expressed in parts of a minute, whereby a better idea can be obtained as to their significance. Tasie I. | I, TI. II. IV. 1 ills x. z. xe 39 Va 58 NO, "003316 -0033649 64 5:083 70 4:74 71 Ay, 74 4°50625 "00299 "00298 79 Ar 127, 80 4:4437 Sloe te hs 85 4°355 86 Ae? "002768 "002802 97 4°17 102 3°885 °002524 "002538 132 3°41 °002222 "002229 154 oe 170 2°95 °00197 "001957 From these results it is seen that the first cardio-arterial interval is longer in slow than in quick pulses, and that it does not increase as quickly as the pulse diminishes in rapidity; but that the statement that it varies inversely as the square root of the rapidity is correct, or very nearly so, is rendered evident by comparing Columns III. and IV., in the latter of which the duration of the first cardio-arterial interval is calculated from the formula #z=39W ax. The chief source of error in these observations is the slight uncertainty in the rate of movement of the watchwork of the instrument, on which the calculation of the rapidity of the pulse depended. | _ On comparing this equation, namely vz=39V 2, with the one above referred to as to the relations of the first cardiac interval, namely xy=20N z, it is evident that the length of the first cardio-arterial interval ig ‘5128, or just over half that of the first cardiac interval, whatever the rate of the pulse. This being the case, a more precise method is acquired of verifying the results arrived at; for by finding the number of times that the first cardio-arterial interval is contained in the first cardiac interval, a constant quantity ought to be the result, which is independent of the. rapidity of 322 Mr. A. H. Garrod on the relation of the Cardiograph [Feb. 23, the pulse. Table II. contains these measurements ; and it may be seen that, though there is a small range of variation, the numbers are all very near to the theoretical requirement, which is 1:95; and their average is 1°983. TaBLe II. Number of times | Number of times that the first car-!! that the first car-| Rapidity of,dio-arterial inter-| Rapidity of|dio-arterial inter- pulse. jval is contained) pulse. jval is contained, in the first car- in the first car-' diac interval. || diac interval. 58 1-95 S615 1-95 | 64 2: e188 21 : 69 1:9 IP ge 2-1 | 70 Peto hes 19959 71 1-975 85°5 1°95 | heey 2°058 86 2: | EA 1:975 88°5 2°05 | | 76 1:98 91 215 | 78 1:9 uo 1°85 : 79 1-925 ba Red 1°95 i 79°5 1°9 HO: O15 80 1:95 | 154 1975 oy { } | It is generally known that in the sphygmograph traces of most slow pulses there is a notch in the first arterial interval, immediately preceding the major fall; and one of the most marked results of the use of the cardio-sphygmograph is the determination of the fact that the point of closure of the aortic valve at the heart is always exactly synchronous with the lowest part of this notch, or the point of abrupt change of direction in the major fall of the sphygmograph trace. This leads to the almost necessary conclusion that the subsequent slight rise or change in direction of the trace is the result of the simultaneous movement of the whole column of blood produced by the suddenness of the shock of closure of the aortic valve, the secondary rise in the same trace being the more slowly transmitted pressure wave resulting from the same cause. The slower the pulse the more distinct is this notch; and by comparing different rapidities, a gradual diminution in its conspicuousness is apparent, it rising higher and higher above the point of termination of the major fall as the pulse is quicker and quicker. When the heart’s rate is about 75 in a minute, the notch is halfway down the major descent, and is partially blended with it ; when over 100 a minute, as the aortic valve closes when the ascent is at its maximum, the notch is so blended with the pressure wave as not to indicate itself separately. In slow pulses, the systolic main rise being quite over when the aortic 1871.] and Radial Sphygmograph Trace. 323 valve closes, the shock wave indicates itself by an abrupt but not con- siderable rise, breaking the very gradual major descent. This explanation being correct, another means is obtained of checking the results arrived at by the combined instrument; and Table III. Column II. contains a few measurements of the number of times that the conjugate arterial interval is contained in the first arterial interval, as found by measuring the ratio of the interval between the commencing arterial rise and the bottom of the notch in the major fall to the whole first arterial interval. Column III. gives the theoretical results necessitated by the equations given above. Tasre III. Number of times the con- jugate cardio-arterial in- terval is contained in the first arterial interval, Rapidity of as found pulse. from as calculated measurement] (approxi- of radial mately). trace. 37 1595 1:6 A5 1635 1°625 58 1:69 a9 1°7083 1°72 60 1°74 1°734 68 Mey 1:78 It may be mentioned that the reason why so few of these instances are given, is that there is considerable difficulty in measuring these small intervals into one another with precision ; but by practice a very fair esti- mate can be made of their value, and in all cases they seem to agree with theoretical requirement. The close accordance of the results obtained by this method in very slow pulses, and the calculated results arrived at from facts relating only to quicker ones, tends strongly to establish the correct- ness of the law given with regard to them. In Table IV. the lengths, in parts of a minute, of the different intervals referred to in this communication, are given as calculated from the equations on which they have been shown to depend. With regard to the second cardio-arterial interval, a reference to Column VII. will show that it varies very slightly within the range of the heart’s action, not being 4 longer in a pulse of 36 than in a pulse of 169 in a minute. 324 Mr. G. Gore on the Thermo-electric [Feb. 23, TaBLe IV. I. II. TIL. IV. ee es, 52 VIL. re Length of| Length of | Length of Rca Length of sepeen pe Poor first cardio- conjugate second car- “te of | Dulse-beat, Gnterval, in | interval, in [22tetial in-| cardio-arte- dio-arterial #15 in parts of a, e ris Of terval, in | rialinterval, interval, in See auntie: | 2. : oF eos A parts of a in parts of a parts of a TAMA. POU = eae. minute. | 2 minute. 36 | 027 0083033 | -006428 ‘0042735 | -0040298 08 | -o0239801 49 | 020408 | -00714286 | :005813 003663 | 00847986 | -00233342 oe | 00227425 81 | -0123457 | -005 00491356 | -0028474 | -0027081 | 00220546 100 | ‘Ol 0046234 | -0025641 | :0024359 | 00218745 004299 002331 | -00221445 | -0020847 0040486 | 0021565 | 0020301 | -0020185 0038485 | 0019704 | 0018756 | -0019729 121 | -0082645 | -0045 144 | -00694 -00416 64 | -015625 | -00625 005319 003205 | 169 | 005917 | 003846 | In conclusion, the following are’the results that have been arrived at by the use of the above cardio- sphygmograph : — 1. The first cardio-arterial interval varies inversely as the square root of the pulse-rate. 2. The conjugate cardio-arterial interval varies inversely as the square root of the pulse-rate. 3. The second cardio-arterial interval varies very little with different pulse-rates, but is slightly longer in slower pulses. 4. The depth of the notch in the first arterial interval of the sphygmo- graph trace occurs at the moment of closure of the aortic valve. 5. There is no definite indication in the sphygmograph trace of the moment at which the arterial systole commences. , II. “On the Thermo-electric Action of Metals and Liquids.” By Grorcr Gors, F.R.S. Received January 13, 1871. It is well known that the degree of rapidity with which a metal immersed in an acid, alkaline, or saline liquid is corroded varies considerably with the temperature, and that the speed of corrosion usually increases with the heat; also a few experiments have been published (Gmelin’s ‘ Handbook of Chemistry,’ vol. i. p. 375) showing that changes of electrical state occur in metals under such circumstances; but a further examination of the relations of the temperature and chemical change to the electrical state has not, that I am aware, yet been made. . In an investigation on the development of electric currents by unequally heated metals in liquids (Phil. Mag. 1857, vol. xii. p. 1), I found that hot 1871.] Action of Metals and Liquids. — 825 platinum was electro-negative to cold platinum in liquids of acid reaction, and positive to it in alkaline ones, provided in all cases chemical action was completely or sufficiently excluded. In the present experiments I have endeavoured to ascertain what electrical changes are produced in cases where chemical action more freely occurs, and I have therefore employed not platinum plates, but plates composed of a metal (copper) which is more easily corroded. To effect the object I had in view, I used the apparatus shown in sec- tion in fig. 1, and in perspective, with its wooden support, in fig. 2. A and B, fig. 1, are two open thin glass dishes, 63 inches diameter, and 14 inch deep, with open necks. The dishes are joined together, water- tight, by a bent glass tube, C, about 1 inch in diameter; and the whole arrangement is securely fixed upon a wooden frame or stand, so that it may be at once placed in an exactly horizontal position, or inverted to pour out its contents. D and E are two dishes of sheet copper of moderate thickness, made from contiguous portions of a sheet of metal to ensure electrical homogeneity in the experiments. Wires of similar metals are attached to the dishes for the purpose of connexion with a galvanometer. A galvanometer, containing about 180 turns of moderately fine copper wire, is sufficiently sensitive for the experiments. The outside of the metal dishes must be made perfectly clean and bright immediately before each experiment. In using the apparatus it is first set exactly horizontal, and a known and measured volume of the clear liquid to be examined, at the temperature of the atmosphere and sufficient to fill it to the line F F, is poured in; the metal dishes are then steadily placed in the glass vessels and connected with. the galvanometer, taking care that no air-bubbles remain beneath them. 326 Mr. G. Gore on the Thermo-electric [ Feb. 23, As soon as the galvanometer-needles have settled at zero, one of the dishes is quickly filled with boiling water, and the directions and amounts of the temporary and permanent deflections noted. The following are Tables of results obtained with various liquids, the solutions being diluted in each case to a specified measure by addition of distilled water. Those of the experiments in which 20 ounces of liquid was used, were nearly all of them made with an apparatus in which the connecting-tube C was of somewhat less diameter; and the deflections obtained by that apparatus were less in extent than those obtained with the “‘ new apparatus,” because in the latter the conduction-resistance was somewhat less. The values of the deflections given in the Tables are in all cases those of the temporary ones ; and the liquid used for diluting the solutions was in all cases water. Pure Nitric Acid. Ounces of strong acid Value of No. diluted to 20 ozs. with water. Deflection. peo elie ay Sek (0045) The hot plate was nega- 2. 3 ‘0012 | tive and much acted upon, 3. z ‘0039 | especially with the stronger 4, 5 ‘0497 | mixtures. With the stronger 5. 1 ‘1177 ( mixtures a little gas was 6. 2 ‘0356 | evolved at 60° Fahr., and a if 3 ‘0578 | large amount directly the 8 4 ‘4954 ) heat was applied. Pure Hydrochloric Acid. Ounces of strong acid Value of No. diluted to 20 ozs. Deflection. | ee a ; 0064) The hot plate was posi- 2. * 0330 rae The amount of stain 3. z -1112 | upon the hot plate was very 4. 7 2854 (small, and was in the form 5. 1 ‘5731 | of a dark line at the edge of 6. 2 2°0446 } the liquid. Chlorie Acid. Ounces of strong acid Value of No. diluted to 20 ozs. Deflection. Dy pais wie high eter 0002 The hot plate was nega- 2. 4 A ere 2016 | tive, and was but little acted 3. 4 ‘0040 | upon. With the strongest 4, 3 ‘0287 ( mixture, the liquid in con- 5. ul "1234 | et with the hot plate soon 6. 2 ‘2005 ) became green. Hydrobromic Acid. Value of pe ne Deflection. No. diluted to 10 ozs. 1160 ( especially with the strongest 10. 400 $5 . "1906 | solutions. ie 500 ss 2 "2241 12. 600 3 S ‘2708 13. 800 = 3 3473 | 14. 1000 os x “4884 15. 2000 5 4237 16. Saute solution (undiluted) -3479 } fodide of Sodium. Grains diluted Value of No. to 12 ozs. Defiection. Me ete AOD ibe ‘0100 Hot copper negative. 4 Liquid alkaline. 2 ke LOO Cy ‘0819 x positive. {| No stains. Carbonate of Sodium. Grains diluted Value of No. to 20 ozs. Deflection. 1B 286 aad 0468 Hot copper positive. 2. 572 Aiite 1673 Liquid alkaline. Biborate of Sodium. Six ounces of a saturated solution diluted to 12 ounces. Hot copper was positive ; value of deflection :0452. Sulphate of Sodium. Grains diluted Value of No to 20 ozs. Deflection. jag AB: RO ap 5 ‘0001 Hot copper negative. 7 eeu lk. | pager § eI Liquid 3 200 ACen ‘0016 *) positive. ( neutral. 4 1000 ae: ‘0170 | 1871.] wee NID OUP oo OES OHONIAH MP toes Action of Metals and Liquids. 331 Phosphate of Sodium. Grains diluted Value of to 20 ozs. Deflection. — 858 sae: 0382 Hot copper positive. 716 haan 0648 Liquid alkaline. Nitrate of Potassium. Value of Grains. Deflection. 50 diluted to 20 ozs. ‘0025 ) LOG, is ‘0107 OOS ae bs 0259 Hot plate positive. No A400; ‘ ‘0647 ~stains at all on the plates. S00)... ‘3 1328 | Solution quite neutral. 1600 ‘2997 Saturated solution (undiluted) 2852 } Chloride of Potassium. Value of Grains. Deflection. 25 diluted to 20 ozs. 0010 } 50, ” ‘0064 | 100°-",,; > 0145 Hot plate positive, and 200: .,, s 0442 | became tarnished at the a00'” ,, * ‘0667 | edge of the liquid, especi- 400 ,, 45 0882 ey with the stronger solu- 000.’ .,, ss "1239 (tions. Traces of copper GOO. ¥ 1896 | were found to have dis- 800. , 95 1874 | solved. The solutions were £000. .,, + ‘2443 | neutral to test-paper. 2000 ‘6371 Saturated solution (undiluted) -8489 J Chlorate of Potassium. : 3 Value of eae _ Deflection. ca 122-5 viwhs 0054 |, Elou plate pee and 245-0 eae 0453 eons tarnished. Solution neutral. Bromide of Potassium. Grains diluted Value of to 20 ozs. Deflection. 100 ey 0497 Hot plate negative. ) No stains. 500 nee -1080 “i Liquid 1000 gees 3150 ” BOSHIVE. neutral. Iodide of Potassium. Grains diluted Value of to 12 ozs. Deflection. 100 Oe "0259 ot No stain. 550) ipa 0459 Hot plate negative. { Liquid 1003 lade ‘0159 4 positive. | neutral. ZC? 332 Mr. G. Gore on the Thermo-electric [Feb. 23, lIodate of Potassium. Value of Deflection. No. Grains. a‘ 100 diluted to 12 ozs. 0064 | Hob plete ie 9 Saturated solution (undiluted) -0100 ) Plates muclustemme Diya j Eee ore ee mation of iodide of copper. Acid Carbonate of Potassium. Value of No. Grains. Deflection. ils 50 diluted to 20 ozs. 0049 > 2. 100 5. 5 0170 3. 200 2a. - "0497 Hot plate positive. The A, 400 _ ,, 0818 | liquid on evaporation was 5. 6.0 Ue ee aan "1329 -green with dissolved ee 6. S00"... * 1978 | Liquid alkaline. Hot pla die 1900 — 2, ss ‘2441 | alone much tarnished. 8. 2000 4210 9, Saturated solution (undiluted) -5451 Carbonate of Potassium. Value of No, Grains. Deflection. i 50 diluted to 20 ozs. ‘0122 ) 2. LOU aeay ‘0382 3. 200s. by 1770 4, 400 __,, ie 3719 5. B00" - ‘7521 ~Hot plate positive. 6. LEOOT b 22400 7. 2400 ——*», 3°7708 8. 3200 4367 9. Saturated solution (undiluted) -4031 } Acid Sulphate of Potassium. Saturated solution (undiluted). Value of deflection 1047. Hot plate negative. ; Bichromate of Potassium. Grains diluted Value of No. to 20 ozs. Deflection. ss args aa ’ ‘leiat Hot metal positive. Chrome Alum. Grains diluted Value of No. to 20 ozs. Deflection. 1 249°8 ae 0019 Hot metal negative. Li- 2 4996 ale 0064 | quid of acid reaction. Aqueous Ammonia. Copper in a mixture of 4 ounces of water and 400 grains of aqueous ammonia at 180° Fahr. was electro-positive to copper in the same mixture at 66° Fahr. iso a ie Action of Metals and Liquids. 333 Nitrate of Ammonium. Grains diluted Value of No. to 20 ozs. Deflection. : a ae Done Hot plate negative. Acid 3. 480 bo 0590 { Teaction. Chloride of Ammonium. Value of No. Grains. Deflection. Le 25 diluted to 20 ozs. 0020 } e Ae a 2 bege Hot copper positive. So- rm 200 7 z 0647 | lutions extremely faintly 5 Oe 2 1533 | acid. Both plates tarnished 6. 800 ” 555] ¢ by the stronger solution; 7 1000 a 7 674 4 but the hot one the most : ” ” 25 so, and a little copper was = — ” ie dissolved =) 211,11 4s ‘7479 g ; 10. Saturated solution (undiluted) °1210 Aqueous Hydrocyanic Acid. Scheele’s strength. The hot plate was feebly positive. Value of de- flection :0006. Cyanide of Potassium. Value of Grains diluted Deflection. No. to 12 ozs. Hot copper positive. Much is 100 sete ‘2854 Jeas evolved from the hot 2. 1000 stan 18164 ) plate only in the strongest solution. Ferrocyanide of Potassium. Value of Grains diluted Deflection. No. to 20 ozs. Hot plate positive. Li- Bers Ses "DOO Hoi fe 0136 } quid feebly alkaline. Both rahe 22s¢i OOD Saga ‘0045 ) plates became pink like new copper. Oxalie Acid. Value of No. Grains. Deflection. 1, 25 diluted to 20 ozs. 54,0008 } 9 . 3 ce 2 2? ee | The hot plate was nega- : 4 a tive, and the plates were 4. 200. ,, % OOLGI GN ee aca Gi all 5. 400 A as ‘0064 no arnishe at all. 6. Saturated solution (undiluted) -0070 | Glacial Acetic Acid. The hot plate was negative. Seven solutions, containing from 74 ounce to 4 ounces by measure of the acid in 20 ounces by measure, gave only extremely feeble currents. The plates remained bright. 334 Mr. G. Gore on the Thermo-electric [Feb. 23, Acetate of Sodium. Grains diluted Value of No. to 20 ozs. Deflection. 1. 50 Lae ‘0016 a, 100 Mead 0070 4 ne as ae Hot plate positive. So- 5. 300 cay 139 lution alkaline to _ test- 6. 1600 ae 2902 | P&per: 6 2000 pee oh 2850 8. 2727 ase 2997 J Acetate of Zine. Grains diluted Value of No. to 20 ozs. Deflection. a; 50 th ‘0001 2. 100 Lae ‘0006 3h 200 b hee fe 70016 gh, 400 ae g 0025 5. 500 es 0020 -Hot plate positive. 6. 800 ee he 240020 te 1000 Batts ‘0012 8. 1600 Big 0004 9, 2000 hn ‘0001 J Crystallized Tartaric Acid. The hot plate was negative. Hight different solutions, varying in strength from 50 to 3200 grains in 20 ounces by measure of the solution, were tried ; but very feeble currents were obtained, and the plates were not tarnished. Crystallized Citrie Acid. The hot plate was negative. With a series of seven solutions, varying in strength from 50 to 3200 grains in 20 ounces of liquid, more feeble results, even, than those with tartaric acid were obtained, and the plates were not tarnished. Probably, with this substance and with others where the resulting currents were very feeble, more distinct effects would be ob- tained by employing a galvanometer of much greater electrical resistance. Several experiments similar to those already described were made with the apparatus shown in fig. 3. The apparatus consists of a glass beaker containing the liquid, and two platinum electrodes—A being a disk of pla- tinum rivetted to a platinum wire enclosed by a glass tube, B, and Ca platinum crucible (for receiving the boiling water) with a platinum wire rivetted to it. Experiment 1.—With a solution of 100 grains of citric acid in 2 ounces of distilled water, the hot platinum cup was negative, the value of the tem- porary deflection being ‘0007. Experiment 2,—With 100 grains of tartaric acid in 2 ounces of water, the hot cup was negative, value of deflection ‘0001. 1871. ] Action of Metals and Liquids. 335 Experiment 3.—With 100 grains of racemic acid in 2 ounces of water the hot cup was negative, value of deflection :000035. The negative condition excited in the hot platinum cup in the solutions of citric and tartaric acid agrees with the results obtained with copper in those liquids. st 2) Fig. 4. _ I have already shown (Phil. Mag. 1857, vol. xii. p. 1) that the currents obtained with platinum electrodes are not due to the influence of atmo- spheric air upon the liquid and metal at their line of mutual contact ; for, in the experiments there recorded, atmospheric air was entirely excluded, and the liquids were previously well boiled. To test the influence of size of the cold electrode, I took a platinum dish, A (see fig. 4), 5 inches wide and 14 inch deep, in a glass vessel of the annexed form, B, closed at its lower end by a cork, and containing in its neck two platinum electrodes, one consisting of a wire, C, and the other of a sheet 2 inches long and 2 inches wide in the form of a cylinder, D. With a cold mixture composed of 33 ounces of water and } of an ounce by measure of strong sulphuric acid, and the sheet of platinum as the lower electrode, on pouring boiling water into the dish a deflection of the value of ‘0064 was obtained, the cold electrode being positive; but with the wire as the lower electrode no perceptible deflection occurred. These results were obtained repeatedly. The electric currents are therefore largely dependent upon the size of the cold electrode. General Results. The chief fact brought out conspicuously by these experiments with copper dishes is, that in many cases an increase of chemical action pro- duced by heat, instead of making the hot metal electro-positive, makes it considerably negative. The results show that hot copper was positive to cold copper in the fol- lowing liquids :—hydrochloric, hydrocyanic, boracic, and tribasic or ortho- phosphoric acids; chloride of copper (weak solution); chloride of cobalt ; chloride of manganese ; chromic acid; chloride of chromium ; sulphate of zine (weak solution); sulphate of magnesia; chloride of calcium; nitrate and chloride of strontium ; chloride of barium ; nitrate of sodium (strong solution) ; chloride, iodide, carbonate, and biborate of sodium ; sulphate 336 Mr. G. Gore on the Thermo-electric [Feb. 23, of sodium (strong solution) ; tribasic phosphate of sodium; nitrate, chlo- ride, and chlorate of potassium; bromide of potassium (strong solution) ; iodide of potassium (strong solution); carbonate, acid carbonate, and bi- chromate of potassium ; aqueous ammonia; chloride of ammonium; cya- nide and ferrocyanide of potassium ; acetate of zinc; and acetate of sodium. And negative in the following ones :—nitric, chloric, hydrobromic, hydro- fluosilicic, and sulphuric acids ; ferrous sulphate ; chloride of copper (strong solution) ; sulphate of copper; sulphate of zinc (strong solution) ; nitrate and iodide of sodium (weak solutions); bromide and iodide of potassium (weak solutions) ; 1odate of potassium ; chrome alum; nitrate of ammo- nium; oxalic, acetic, tartaric, and citric acids. The number of liquids in which hot copper was positive was ay -six, and of those in which it was negative was twenty. In several instances where the hot metal was negative with a weak solu- tion, it became positive with a strong one—for instance, with sulphate of zine, nitrate, iodide, and sulphate of sodium, bromide and iodide of potas- sium ; but with chloride of copper the reverse occurred. These results may be connected with the fact that in weak neutral solutions the chemical action is generally the most feeble, and therefore interferes the least with the direct influence of the heat in producing electric currents. The influence of free hydrochloric, hydrocyanic, boracic, orthophosphoric, and chromic acids was to make the hot copper positive; whilst that of nitric, chloric, hydrobromic, hydrofluosilicic, sulphuric, and some of the organic acids was to make it negative. In consequence, probably, of the small amount of interference by che- mical action in solutions of oxalic, acetic, tartaric, and citric acids, the direct influence of the heat made the copper negative—similar to its influ- ence on platinum in all acid liquids which do not attack that metal. The nature of the acid in a salt appears to exert much more influence than that of the base on the direction of the current; for instance, in nearly all chlorides, including those of a considerable variety of bases, hot copper was positive, probably because copper is more readily attacked by acids than by bases. In all decidedly alkaline liquids the hot copper was positive; this is similar to the behaviour of platinum in such solutions, and is probably due to the same cause, viz. the direct influence of the heat, as well as to che- mical action. The results also show that the quantity of the current obtained with any given liquid generally increases with the number of molecules of the sub- stance contained in the solution; in some cases, however, as with sulphuric acid, carbonate of potassium, chloride of ammonium, and acetate of zinc, there was a limit to this increase; and beyond that limit the quantity of the current decreased up to the point of saturation of the liquid. In the great majority of cases the value of the deflection increased much more rapidly than the strength of the solution, particularly with solutions 1871.] Action of Metals and Liquids. 337 of sulphate of magnesia, and also of hydrochloric acid and of chloride of sodium, probably because two causes operated, viz. increased strength of solution and diminished conduction-resistance ; in a very few cases, how- ever, the opposite result took place, as with solutions of chloride and nitrate of strontium. Inversions of the direction of the deflection by difference of strength of the liquid occurred with solutions of chloride of copper, sulphate of zinc, nitrate, iodide, and sulphate of sodium, bromide and iodide of potassium. Irregularities of the amount of deflection were very apt to take place with liquids which gave strong deflections, or which acted much upon the copper plates (for instance, nitric acid), especially if bubbles of air remained under the plates, or the dishes were wetted on their side above the liquid by the solution. In certain acid liquids, viz. nitric, chloric, hydrobromic, hydrofluosilicic, and sulphuric acids, the hot copper was strongly negative (notwithstanding the chemical action upon it was distinct, and ‘in some cases even strong) ; this is similar to the electrical behaviour of platinum in such liquids, and may be attributed either to the more direct influence of the heat alone (such as occurs with platinum plates), or to a different influence of the chemical action produced by the heat. Both these causes probably ope- rate in such cases. It is probable that in all cases where the hot copper was positive in liquids of strongly acid reaction, the positive condition was due to chemical action alone. With some liquids, especially with solutions of hydrocyanic, boracic, acetic, tartaric, and citric acids, the deflections were very feeble, and the chemical action on the plates not perceptible; whilst with others, such as nitric and chloric acids, solutions of the chlorides of strontium, sodium, potassium, and ammonium, and of carbonate, acid carbonate, and cyanide of potassium, the deflections were considerable, and the chemical action distinct, and in some cases strong. In none of the liquids (except hydro- bromic and chromic acids) did the hot plate appear to be Jess stained or corroded than the cold one; probably in all cases it was the most corroded, although in some cases the corrosion was not perceptible. The amount of deflection was not always proportionate to the amount of chemical action; for instance, with solutions of chloride of copper and iodate of potassium there was considerable corrosion, but only feeble cur- rents, probably because the plates became covered with a badly conducting film, whilst with hydrochloric acid, chloride of cobalt, chloride of manga- nese, and nitrate of potassium the reverse occurred. I consider the currents in all these experiments of difference of tempera- ture to be due either, lst, to the direct influence of heat, the effect of which is to make the hot copper negative in acid liquids and positive in alkaline ones (see Phil. Mag. 1857, vol. xiii. p. 1); 2nd, to chemical action, which sometimes overpowers the direct influence of heat and reverses the effect ; 338 Mr. G. Gore on the Thermo-electric [Feb. 23, or, 3rd, to both these influences combined. The more ultimate cause, however, of the phenomena in these cases must be sought for in the mo- lecular movements produced by heat in the metals and liquids. The currents obtained with copper plates were no doubt influenced in their amounts (if not also in their direction) by the oxidizing action of the air upon the liquid and metal at their line of mutual contact ; for we know that metals in contact with liquids oxidize much more quickly if oxygen has access to their wet surfaces. And the currents were also influenced by the action of unequal temperature upon this air-contact line; for we know that wet metals oxidize still more rapidly if heat is applied. Influence of line of contact of liquid and metal with the air. That the length of line of contact of the liquid and copper with the air is capable of producing electric currents was shown by the following experiments :— Two strips of sheet copper of the annexed form, fig. 5, ? inch wide, and Fig. 5. 12 inches long in the longest limb, were cut from contiguous parts of a sheet of copper, and, after being perfectly cleaned, were coiled into the shape represented by the annexed sketch, fig.6. They were then placed in a flat-bottomed porcelain dish and connected with the galvanometer, one of the spirals being supported at about 7 inch higher than the other by means of a triangle of glass rod. The liquid to be examined was then poured into the dish until it just (and completely) covered the lower spi- ral, and the direction and amount of the permanent deflection noted. The positions of the spirals were then reversed and the electrical effects again noted. Experiment 1.—With a liquid composed of 100 grains of cyanide of potassium dissolved in 12 ounces of water, whichever of the spirals was only partly submerged and therefore had the longest air-line, was strongly electro-negative to the wholly submerged one. Experiment 2.—With a mixture of one measure of strong nitric acid and ten measures of water, deflections of somewhat less amount, but in pre- cisely similar directions to those of experiment |, took place. Experiment 3.—With dilute hydrobromic acid the directions of the deflections were also similar, but still less in amount. Experiment 4.—With a half-saturated solution of borax very feeble de- 1871.] Action of Metals and Liquids. 339 flections, agreeing in direction with those of the other experiments, were obtained. These results show the necessity (which I have already mentioned) of excluding air-bubbles from beneath the copper dishes, and of not wetting the sides of the dishes by the liquid above the level of their immersion. To ascertain the influence of difference of temperature of the air-contact line I soldered two strips of perfectly similar sheet copper, each 12 inches long and 4 inch wide, in the form of circular hoops 4 inches in diameter upon the bottoms of two tin cups, and ground the edges of the strips perfectly level, and soldered copper wires to them for connecting with the galvano- meter. Two glass triangles were now put into the apparatus, fig. 1, one in each dish, to support the cups, and a mixture of one measure of nitric acid and 12 measures of distilled water poured in until it just touched the edges all round of the perfectly horizontal copper rims resting on the tri- angles. After the needles of the galvanometer had settled at zero, about ten ounces of boiling water was poured into one of the cups; a temporary deflection of the value -0560, and a permanent one of value ‘0759, were produced, the hot metal being negative. The direction of the current in this experiment agrees with that obtained with the same mixture and the copper dishes ; and the result indicates that a large proportion of the quan- tity of the current obtained with copper dishes in dilute nitric acid was due to the action of the air-contact line. The influence of the air-line is largely chemical. ‘A piece of copper wire wholly submerged in the acid [dilute sulphuric] so as to entirely exclude any portion of it coming into contact with the air, has remained for many months without imparting the slightest tinge to the liquid.” *‘ But on suffering the liquid to evaporate so as to bring the upper end of the metal near to its surface, the instant the slightest portion becomes ex- posed chemical action immediately begins.” ‘Two equal portions of wire were similarly placed in acid, only that one was fully exposed to the atmosphere in an open tube, while the other was placed in a phial, the acid occupying half its height, and was kept closely corked for several weeks—after which the fully exposed metal had lost in weight two-fifths more than the one which had been excluded from contact with fresh portions of air, showing that contact with the atmosphere in bulk is necessary to the fullest action’’*. Experiments with Inquids of unequal strength. To throw some light upon the questions,—Ist, Is the quantity of the current simply a result of the difference of number of molecules of liquid which touch the hot plate compared with those which touch the cold plate? and, 2nd, What amount of difference of strength of a liquid is equal to the amount of difference of temperature employed ?—I brought the two * “Qn the Theory of the Voltaic Pile,” Bridgman, Phil. Mag. Nov. 1869. 340 Mr. G. Gore on the Thermo-electric [Feb. 23, copper dishes into contact with liquids of unequal strength instead of un- equal temperature. The tube C (fig. 1) was filled with the stronger mixture and closed at its end in the dish A by an india-rubber bung, and the dish B filled to the line F with the same mixture; the dish A was then filled with the weaker mix- ture up to the same level and the bung slowly withdrawn. The two cop- per dishes, previously connected with the galvanometer, were next simul- taneously immersed in the mixtures and the effect noted. The following are the results obtained by this method :— Nitric Acid. Experiment 1.—In A, 1 volume of acid diluted to 80 volumes. In B, 1 volume diluted to 40. Copper in A was positive temporarily, valne -0270; and permanently, value :0198. Experiment 2.—In A, 1 volume of acid diluted to 40 volumes. — In B, 1 volume of acid diluted to 20 volumes. The copper plate in A was first positive temporarily, value of deflection 0064; and then that in B per- manently, value -2850. Experiment 3.—In A, 1 volume of acid diluted to 40 volumes. In B, 1 volume diluted to 10 volumes. Copper plate in B was positive tempo- rarily, value ‘4863 ; and permanently, value -0819. Hydrochloric Acid. Experiment 1.—In A, 1 volume of acid diluted to 40 volumes. In B, 1 volume diluted to 20 volumes. The copper in B was positive temporarily, value ‘9608 ; and permanently, value °1087. Experiment 2.—In A, 1 volume of acid diluted to 40 volumes. In B, 1 volume diluted to 26°66 volumes. The copper in B was positive tempo- rarily, value °3479 ; and permanently, value -0702. Chlorie Acid. In A, 1 volume of acid diluted to 80 volumes. In B, 1 volume diluted to 40 volumes. The copper in B was positive temporarily, value -0036 ; and permanently, value -0009. Sulphuric Acid. In A, 1 volume of acid diluted to 80 volumes. In B, 1 volume diluted to 40 volumes. The copper in B was positive temporarily, value 0467 ; and permanently, value °0330. On examining these results, it will be perceived, Ist, that only in one half the number of the experiments did increased strength of liquid pro- duce electrical currents similar in direction to those produced by increased temperature; and therefore the heat does not act simply by causing a greater number of molecules of each individual substance to touch the hot plate; and, 2nd, that only in one of the experiments was the copper in the weaker liquid both temporarily and permanently positive to that in the 1871.] Action of Metals and Liquids. 341 stronger ; whilst in five of the experiments the copper in the stronger liquid was temporarily and permanently positive to that in the weaker. Increase of strength of the liquid therefore made the copper posiéive in five cases out of six. In the fourth experiment with hydrochloric acid with difference of tem- perature, and in the second one with difference of strength, the mixture in each case consisting of 1 volume of acid diluted to 40 volumes with water, an increase of temperature from 16° to about 98°C. produced a deflection of the value *2854, whilst an increase of strength to 1 volume in 26°66 gave a deflection in the same direction of the value 3479. An increase of temperature of about 82°C. was not quite equal in electrical effect to an increase of 50 per cent. in the number of molecules of the acid which touched the plates. In the third experiment with chloric acid with difference of temperature, and in the single one made with difference of strength, the mixture in each instance consisting of 1 volume of the acid diluted to 80 volumes with water, an increase of temperature of about 82° C. produced an electrical effect of 0040; whilst an increase of 100 per cent. in the number of molecules of the acid which touched the plates produced an opposite electrical effect of "0036. | In the third experiment with sulphuric acid with difference of tempera- ture, and in the single one made with difference of strength, each being with a mixture of 1 measure of acid in 80 of water, an increase of temperature of about 82°C. caused an electrical effect of 0418, and an increase of 100 per cent. in the number of molecules of acid which touched the plates caused an opposite electrical effect of -0467. A liquid thermo-electric battery. Acting upon the general results thus obtained in this subject, [ con- structed a liquid thermo-electric battery consisting of twelve glass tubes, Fig. 8. taining a platinum wire hermetically sealed in that end), and bent to the 342 Mine) Gore\on eke Wheanp leer [Feb. 23, form shown in fig. 7, each tube being filled with a conducting liquid, and its outer end closed by a cork, in which was fixed a second platinum wire to dip into the liquid. Fig. 8 represents the apparatus; A A is a wooden stand supporting a tin box, B. The box is water-tight, and has in its lower surface a long semi- circular cavity (shown by dotted lines) to receive the upper ends of the twelve tubes. To the back of the box is fixed a short cylinder of tin, C, closed at its outer end. When the apparatus is in action, the box is filled with hot water, and the water kept boiling by means of a lamp placed be- neath the tube C. The twelve tubes were kept in position by divisions of wood fixed to the back of the stand, as shown in the figure. The tubes 1, 3, 5, 7, 9, and 11 were filled with a previously boiled and cooled mixture of 7 of an ounce of sulphuric acid, and 19 ounces of di- stilled water ; and the others, viz. 2, 4, 6, 8, 10, and 12, with a similarly prepared solution of 110 grains of hydrate of potassium dissolved in 19 ounces of distilled water. The platinum wires were connected, in the order shown in the sketch, by means of small binding-screws not represented in the figure. On connecting the terminals with a galvanometer containing about 180 turns of moderately coarse copper wire, and applying heat to the upper electrodes and ends of tubes by means of the boiling water, no deflection of the needles took place ; but on substituting a Thomson’s reflecting galvano- meter, which offered a resistance of 3040°7 B.A. units (=77872°327 miles of copper wire ;), of an inch thick), a deflection of 40 degrees was readily ob- tained, the hot platinum wire in the dilute acid being negative, and that in the alkali positive, as shown by the direction of the arrows in the sketch. From these results it is evident the quantity of the electric current pro- duced was exceedingly small, and its intensity considerable. By employing electrodes of larger surface, such as spirals of platinum wire and more con- centrated liquids, the quantity of the current would be very largely in- creased. (See Phil. Mag. 1857, vol. xiii. p. 1.) 1871.] Action of Metals and Liquids. 343 one kind of liquid, either acid or alkaline, is employed. The electrodes in this arrangement must be disposed in the order represented by the figure. Influence of Friction. To ascertain if the friction of one of the electrodes against the liquid had similar effects to those produced by the direct application of heat, I employed the apparatus shown in fig. 10. The sketch does not require explanation. Experiment 1.—By immersing two stout copper wires vertically in an acidulated solution of cupric sulphate and rotating one of them at a speed of about 5000 revolutions per minute, the rotating wire became electro- positive. Experiment 2.—With a saturated solution of borax, the rotating wire was positive. : Experiment 3.—With a solution of cyanide of potassium, the rotating wire was negative. Experiment 4.—With stout platinum wires in an acidulated solution of cupric sulphate, the rotating wire became negative. Experiment 5.—With platinum wires in a solution composed of 200 grains of carbonate of potassium in 40 ounces of distilled water, the rota- ting wire was faintly positive, and similarly in a very dilute solution. Experiment 6.—With two platinum disks one above the other in a strong solution of carbonate of potassium, revolving the upper disk at a speed of about 5000 revolutions per minute made it electro-positive. Experiment 7.—With an acidulated solution of cupric sulphate, the revolving disk became feebly negative. On comparing these results with those obtained by unequal temperature, we find that the directions of the currents in the two classes of cases were reverse with copper in solutions of acidulated cupric sulphate and cyanide of potassium, and similar in a solution of borax; and with platinum in solutions of acidulated cupric sulphate or carbonate of potassium the in- 344: Mr. G. Gore on the Thermo-electric [Feb. 23, fluence of friction and of increased temperature upon the direction of the currents were the same. The molecular movements, therefore, produced by friction are not in all cases similar to those produced by heat. Influence of Magne-optic rotating-power of the Liquids. Being desirous of determining whether the thermo-electric properties of liquids were dependent on the molecular structure by virtue of which liquids under the influence of magnetism polarize light circularly, I made the fol- lowing apparatus and experiment : — A and B (fig. 11) are two straight glass tubes, about } inch in diameter and 10 inches long, with two similar (but bent) So tubes, C and D, attached to their free ends by Sanaa india-rubber tubing. The sloping ends of the ay straight tubes are ground flat, and are joined together securely at their edges by melted shel- ff lac, with a thin and projecting sheet of platinum between them to separate the liquids. E and F are two strong electro-helices wound upon stout tubes of soft iron which enclose the glass tubes. The apparatus is secured upon a board in an inclined position with the sloping ends. of the tubes uppermost; and the two helices are held together at their upper ends by an india-rubber band, G. I filled one of the tubes with a clear and strong solution of perchloride of iron (of negative magne-optic rotatory power, see Verdet, Phil. Mag., June 1858), and the other with a similar solution of chloride of nickel (of positive magne-optie rotatory power), and connected the liquids in the bent tubes with a galvanometer 16 feet distant by means of the platinum wires H and I. I now excited the helices in various ways by means of 12 strong Grove’s cells; no cur- rent was induced in the liquid. I next heated the junction of the tubes gradually ; the solution of iron became thermo-electro-positive, and a steady but feeble deflection of the needles took place; and during the continuance of this current I again excited the helices in various ways as before; again no electrical effects were produced. The results of this experiment strongly support the conclusion that the thermo-electric properties of liquids are not dependent upon the magne-optic polarizing power of the liquids, nor upon the properties of their mass. On examining the thermo-electric properties of the solution of ferric chloride with platinum plates in the apparatus described in the ‘ Philoso- phical Magazine,’ 1857, vol. xiii. p. 1, the hot platinum was strongly negative, value of temporary deflection *8475. With the nickel solution, similarly examined, the hot plate was also negative, value of deflection ‘0409. These results agree with that obtained with the two tubes in the last experiment, the more positive condition of the iron solution than that of the nickel one determining the direction of the current in that experiment. 1871.) _ Presenis. | 345 General Conclusion.—The electric currents produced by the direct in- fluence of unequal temperature or friction of platinum or copper electrodes, in conducting liquids which do not act chemically upon those metals, have their origin in temporary changes of cohesion of the layers of metal and liquid which are in immediate and mutual contact, and may be considered a very delicate test of the kind and amount of temporary molecular movements produced by those causes. Presents received February 2, 1871. Transactions. Devonshire Association for the Advancement of Science, Literature, and Art. Report and Transactions. Vol. LV. Part 1. 8vo. Plymouth 1870. The Association. Turin :—R. Accademia delle Nolen. Atti. Appendice al Vol. IV. Vol. V. disp. 1-7. 8vo. Torino.1869-70. Notizia Storica dei lavori fatti dalla Classe di Scienze Fisiche e Matematiche negli anni 1864 e 1865. 8vo. Torino 1869. The Academy. Observations and Reports. Calcutta:—Report of the Meteorological Reporter to the Government ’ of Bengal. Meteorological Abstract for the year 1869, by H. F.: Blanford. fol. Calcutta 1870. The Government of India. Another copy. The Meteorological Office. London :—Army Medical Department. Report for the year 1868. Vol. X. 8vo. London 1870. The Department. San Fernando:—Observatorio de Marina. Anales. Seccion 24, Obser- vaciones Meteorologicas, ano 1870. fol. San Fernando 1870. ) The Observatory. Turin :—Regio Observatorio. Bollettino Meteorologico ed Astronomico. Anno 4. 1869. 4to. Zorino. The Observatory. Journals. Bibliothéque Universelle. Archives des Sciences Physiques et Natu- relles. No. 120, 153-156. 8vo. Genéve 1867-70. 7 | | The Editor. Entomologist’s (The) Annual for 1871. 12mo. London. , H. F. Stainton, F.R.S Symons’s Monthly Meteorological Magazine. No. 54-60. 8yo. Londen 1870-71. The Editor. Zeitschrift fiir die gesammten Naturwissenschaften, redigirt von C. G. ‘Giebel und M. Siewert. Neue Folge. 1870. Band I. 8vo. Berlin. The Editors. VO SIM: 2D 346 Presents. [Feb. 9, Bashforth (Francis) Reports on Experiments made with the Bashforth Chronograph to determine the resistance of the Air to the Motion of Projectiles, 1865-70. 8vo. London 1870. The Author. Colding (M. A.) Extrait d’un Mémoire sur les lois des Courants dans les Conduites ordinaires et dans la Mer. 4to. Copenhague. The Author. Colnet d’Huart (de) Mémoire sur la théorie Mathématique de la Chaleur et de la Lumiére. 4to. Luxembourg 1870. The Author. Martins (Ch.) et G. Chancel Des Phénoménes Physiques qui accom- pagnent la rupture par la Congélation de Eau des projectiles creux ~ de divers calibres. 4to. Montpellier 1870. | The Authors. Mensbrugghe (G. vander) Sur un principe de Statique Moléculaire avancé par M. Ludtge. 8vo. Bruselles 1870. The Author. Phillips (L. B.) Horological Rating Tables for ascertaining the daily rate of Watches and Chronometers. 8vo. London 1871. The Author. Playfair (Lyon), F.R.S. The Inosculation of the Arts and Sciences. 8vo. Birmingham 1870. The Author. Savory (W. 8.), F.R.S. The Relation of the Vegetable and Animal to the Inorganic Kingdom, a Lecture. 8vo. London 1861. On the Absorp- tion of Dead Bone. 8vo. London 1864. An Experimental Inquiry into the effect upon the Mother of poisoning the Foetus. 8vo. London. On the relative Temperature of Arterial and Venous Blood. 8vo. London. On the Shape of Transverse Wounds of the Blood-vessels in relation to their Physiology. 8vo. London. The Author. February 9, 1871. Transactions. Munich :—Konigl. bayer. Akademie der Wissenschaften. Sitzungsbe- richte, 1870. II. Heft 1,2. 8vo. Miinchen 1870. 3 The Academy. Utrecht :—Provincial Utrechtsch Genootschap van Kunsten en Weten- schappen. Natuurkundige Verhandelingen. Nieuwe Reeks. Deel 2. Stuk 1,2. 4to. Utrecht 1870. Verslag van het Verhandelde in de algemeene Vergadering. 8vo. Utrecht 1870. Nederlandsch Me- teorologisch Jaarboek voor 1869. Jaargang 21. Deel 1. 4to. Utrecht 1869. The Society. Venice :—Reale Istituto Veneto di Scienze, Lettere ed Arti. Vol. XIV. Par.3; Vol. XV. Par. 1. 4to. Venezia 1870. Atti. Tomo XIV. Disp. 6-10; Tomo XY. Disp. 1-9. 8vo. Venezia 1868-70. The Institute. Ateneo Veneto. Atti. Serie2. Vol. V. Puntata 4. 8vo. Veneza 1869. The Ateneo. 1871.] Presents. 347 Ballard (K.) On a localized Outbreak of Typhoid Fever in Islington, during the months of July and August 1870, traced to the use of impure Milk. 8vo. London 1871. The Author. Clausius (R.) Ueber einen auf die Wirme anwendbaren mechanischen Satz. 8vo, 1870. Ueber die Zuriickfiihrung des zweiten Hauptsatzes der mechanischen Warmetheorie auf allgemeine mechanische Principien. Svo. 1870. The Author, by Dr. Tyndall, F.R.S. Wilson (Erasmus), F.R.S. Lectures on Dermatology; a Synopsis of Diseases of the Skin. 8vo. London 1871. The Author. Two Photographs of the Skeleton of the Hooded Dodo (Didus ineptus). 4 The Trustees of the British Museum. Engraved Portrait of Joseph Hodgson, F.R.8., from a Painting by John Partridge, 1849. Prof. Partridge, F.R.S. Plaster Bust of Sir Francis Ronalds, F.R.S., by E. Davis. S. Carter, Esq. February 16, 1871. Transactions. Cambridge, Mass.:—American Association for the Advancement of Science. Proceedings, Eighteenth Meeting, held at Salem, Mass., August 1869. 8vo. Cambridge 1870. The Association. Harvard College. Annual Reports of the President and Treasurer, 1868-69. 8vo. Cambridge 1869. Report of the Board of Overseers. 8vo. Cambridge 1869. Catalogus Universitatis Harvardiane, 1869. Catalogue of the Officers and Students, 1869-70. 12mo. Cam- bridge 1869. Addresses at the Inauguration of C. W. Eliot as Pre- sident. 8vo. Cambridge 1869. Catalogue of the Collection of En- gravings bequeathed by Francis C. Gray, by L. Thies. 4to. Cam- bridge 1869. The College. London :—British Pharmaceutical Conference. Year Book of Pharmacy, with the Proceedings at the Seventh Annual Meeting held at Liverpool, Sept. 1870. 8vo. London 1870. The Conference. Geological Society. Quarterly Journal. No. 103-105. 8vo. London 1870-71. The Society. Society of Antiquaries. Proceedings. Second series. Vol. IV. No. 9. 8vo. London 1870. The Society. Observations, &c. Dresden :—Resultate aus den meteorologischen Beobachtungen ange- stellt an den fiinfundzwanzig Konigl. Sichsischen Stationen im Jahre 1868, von C. Bruhns. Jahrgang 5. 4to. Dresden 1870. The Author. London :—Meteorological Office, Quarterly Weather Report. Part 3. Ato. London 1871. The Office. New York :—Annual Report of the Adjutant-General. 8vo. Albany 1870. The State of New York. 348 Presents. [Feb. 23, Blyth (E.) Mr. W. Theobald and Dr. Falconer. 8vo. London 1870. The Author. Boettcher (A.) Ueber Entwickelung und Bau des Gehorlabyrinths nach Untersuchungen an Siugethieren. Theil 1. 4to. Dresden 1869. The Author. Lea (Isaac) A Synopsis of the Family Unionide. Fourth edition. 4to. Philadelphia 1870. The Author. Phillips (J. A.) On the Chemical Composition and Microscopic Constitu- tion of certain Cornish Rocks. 8vo. London 1871. The Author. Preudhomme de Borre (A.) Considérations sur la Classification et la distribution géographique de la famille des Cicindélétes. 8vo. Bruwelles 1870. The Author. February 23, 1871. Transactions. Birmingham :—Institution of Mechanical Engineers. Proceedings, 1868, Leeds Meeting, Part 1; 1870, April 28; Aug. 2, 3 (2 parts), Noy. 10. 8vo. Birmingham 1868-70. The Institution. Edinburgh :—Royal Society. Transactions. Vol. XXVI. Part 1. 4to. Edinburgh 1870. Proceedings, Session 1869-70. 8vo. Hdinburgh 1870. The Society. London :—Entomological Society. Transactions for the year 1870. Part 2-5. 8vo. London 1870. The Society. Kast India Association. Journal. Vol. IV. No. 4. 8vo. London 1870. Debates in both Houses of Parliament relating to India during the Session of 1870. 8vo. London 1870. The Association. University of London. Calendar for the year 1871. 8vo. London 1S 7Ay The University. Newcastle-upon-Tyne. Iron and Steel Institute. Transactions. Vol. I. No. 5-7. Journal. No. 1. 8vo. Newcastle 1869-71. Darwin (C.), F.R.S. The Descent of Man, and Selection in relation to Sex. 2 vols. 8vo. London 1871. The Author. Dunkin (E. H. W.) Some Account of the Megalithic Remains in South Dorset. 8vo. London 1871. The Author. Griffin (L. H.) The Rajas of the Punjab, being the History of the principal States in the Punjab and their political relations with the British Government. 8vo. Lahore 1870. The Punjab Government. Guy (Dr.), F.R.S. On the Claims of Science to Public Recognition and Support, with special reference to the so-called “ Social Sciences.” 8vo. London 1870. The Author. Recueil de Documents sur les Exactions, Vols et Cruautés des Armées Prussiennes en France. 8vo. Bordeaux 1871. Messrs. J. M. Johnson and Co, 1871.] On the Effect of Diet &c. on Elimination of Nitrogen. 349 March 2, 1871. General Sir EDWARD SABINE, K.C.B., President, in the Chair. In accordance with the Statutes, the names of the Candidates for elec- tion into the Society were read as follows :— Andrew Leith Adams, Surgeon- Charles Horne. Major. Rev. A. Hume, LL.D. Robert Dudley Baxter. Edmund Charles Johnson. William Henry Besant, M.A. M. Kelburne King, M.D. Henry Bowman Brady. John Leckenby. William Budd, M.D. Alexander Moncrieff, Capt., M.A. George William Callender, F.R.C.S. | Thomas George Moutgomierie, Major Edwin Kilwick Calver, Capt. R.N. R.E. William Carruthers. Richard Norris, M.D. Frederick Le Gros Clark. Edward Latham Ormerod, M.D. John Cleland, M.D. Oliver Pemberton. Herbert Davies, M.D. John Arthur Phillips. Walter Dickson, M.D. Richard Quain, M.D. Henry Dircks. Edward James Reed, C.B. August Dupré, Ph.D. George West Royston- Pigott, M.D. Robert Etheridge. Carl Schorlemmer. Alexander Fleming, M.D. John Shortt, M.D. Peter Le Neve Foster, M.A. Peter Squire. Wilson Fox, M.D. Edward Thomas. Arthur Gamgee, M.D. Edward Burnet Tylor. Thomas Minchin Goodeve, M.A. Cromwell Fleetwood Varley. Frederick Guthrie, B.A. Arthur Viscount Walden, P.Z.S. John Herschel, Capt. R.E. A. T. Houghton Waters, M.D. Edmund Thomas Higgins, F.R.C.S. | Charles William Wilson, Capt. R.E. Rev. Thomas Hincks, B.A. John Wood, F.R.C.S. Trevenan James Holland, Major,C.B. | Edward Perceval Wright, M.D. I. “ Further Experiments on the effect of Diet and Exercise on the Elimination of Nitrogen.” By E. A. Parxzs, M.D., F.R.S. Received January 28, 1871. In the Proceedings of the Royal Society (No. 89, 1867, and No. 94, 1867) some experiments were published on the elimination of nitrogen, durmg exercise and rest, on a nitrogenous and a non-nitrogenous diet. The result of both series was so far to confirm the experiments which show that the changes in the nitrogen of the urine and feces are small in extent and afford no measure of the work; but there did appear to be a slight effect produced in two ways :— VOL. XIX. 25 350 Dr. Parkes—Further Experiments on the [Mar. 2, 1. There was an increased, though slight, outflow of nitrogen after work. 2. There was apparently a slight lessening of the outflow during work, not dependent on diminution in the amount of urinary water. In the state of rest also, when the diet was equal, there was no lessening, but a slight excess, in the excretion of nitrogen as compared with a period both of forced and ordinary exercise. Professor Karl Voit, of Munich, who has a worldwide reputation for his numerous and important contributions to this subject, and who denies that exercise produces any change in the nitrogen, has taken exception to some of these experiments, on the ground more particularly that the daily ingress of nitrogen could not have been kept sufficiently stable. I believe the ex- periments, showing as they do in two men a remarkable agreement in the amount of nitrogen eliminated, and the fact that the two great articles of diet by which nitrogen enters (meat and bread) were selected and weighed with great care* and from the analyses appeared to be of constant compo- sition, prove that the alterations in the daily inflow of nitrogen must have been very small and less than those of the outflow. Undoubtedly, however, to insure an absolute uniformity in the entrance of nitrogen in men, is a very difficult matter as long as only ordinary diet is given. The employment of prepared or concentrated food, on the other hand, cannot be considered as good as common diet for such experiments ; for the body is unaccustomed to the particular form in which the food is given. It was determined to repeat the experiments in two or three ways. First, not only to use ordinary diet with the usual attention to keep it as uniform as possible from day to day, but to select hours for rest and exercise when the influence of diet is least perceptible, viz. twelve or fourteen hours after food ; then in a second series to use prepared food in which the amount of nitrogen is absolutely constant; and thirdly to use a diet without nitrogen. Unfortunately the experiments on preserved food failed on account of the health breaking down in a few days and before any exercise could be taken. On the ordinary diet also an unexpected difficulty arose, but still the results are worthy of record. The experiments on the non-nitrogenous diet are confirmatory of the former results, as far as the increased elimi- nation after exercise is concerned. As the details of the experiments would occupy too much space, I have given only mean numbers when these were sufficient to fairly show the results, and have omitted all details of the chloride of sodium, free acidity of the urine, and other matters. The subject of the experiments was T. C., a perfectly healthy soldier * The meat was beefsteak, and was selected free from visible fat, and was always cooked in the same way, 7. ¢. fried: The bread was the hospital bread, made daily with the same flour, water, and salt, baked at the same heat and for the same time, and having the same amount of crust and crumb. 1871.] Effect of Diet &c. on Elimination of Nitrogen. 351 who had never had a day’s illness in his life. He was 25 years of age, weighed usually 145 lbs., and is of very temperate habits. He had been an iron-worker before enlistment, and is an extremely powerful man; the girth of the chest was 372 inches. First SERIES or EXPERIMENTS. Ordinary regulated diet. During 20 days the man received daily beefsteak weighing 14 ounces when raw, | ounce of fat for cooking, 16 ounces of bread, 1 ounce of butter, 6 ounces of milk, 16 ounces of potatoes, 1$ ounce of sugar, 36 fluid ounces of infusions of tea and coffee, and 16 ounces of water. The amount of nitro- gen was determined at 300 grains; it might be a little more or less, but still from day to day its amount was the same as far as it could possibly be kept so. This diet was selected in this, as in the former experiments, because it is the usual ration of the Army Hospital Corps to which this man belonged, and therefore there was no fear of a change in the food itself producing any effect. He took his meals always at the same time; viz. breakfast at 10 a.m., dinner at 3 p.m. (when he took the whole of his meat), and tea at 7 to 6. After tea he took 6 ounces of water at 10 p.m., but no solid food. The urine was collected from 10 a.m. to 6 a.m. on the following morn- ing; then from 6 a.m. to 8 a.m. and from 8 a.m. to 10 a.m. As all food was taken between 10 a.m. and 6 P.M., it was expected that the urine from 6 a.m. to 10 a.m. (viz. from the 13th to the 16th hours after food) would be of tolerably constant composition ; at any rate there would be less chance of error from the effect of food. In this way, and by keeping as far as possible an equal daily diet, it was hoped to lessen or remove the chances of fallacy from varying ingress of nitrogen. An unexpected circumstance partly disconcerted this hope. It was anticipated that the amount of urine passing in the two hours from 8 to 10 a.m. would be less than in the two hours from 6 to 8, as being further removed from the time when fluid was taken. But the result was otherwise ; there was always more urine passed from 8 to 10 a.m. than in the previous two hours. When this was first noted, it was supposed that an error in collecting the urine had been made; but day after day the result was the same. It seemed to be owing to the influence of sleep and wakefulness. From 6 to 8 the man slept, but from 8 to 10 he was not only awake, but his mind was active, and he talked to two men who worked in the room where he slept; and though his body was kept as quiet as during the previous two hours, the mental condition seemed to cause an Increased passage of urine; at least there seemed nothing else to account for the fact that on every day during ten days while he was still in bed, there was more urine passed from 8 to 10 than from 6 to 8 4.M., although no water had been taken except at 10 the night before. ‘The result was 252 352 Dr. Parkes—Further Experiments on the —_ [Mar. 2, that the urea did not fall as was expected, though its percentage was les- sened. Liebig’s mercuric nitrate solution (the chloride of sodium being got rid of and the usual correction for dilution being made) and Voit’s plan for the determination of nitrogen by soda-lime were both used, so as to afford a control of the observations. The daily weight of the body, the temperature of the axilla and reetum, the pulse, the weight of the stools, &c. were also determined. Almost all the experiments were repeated, and several were performed three and four times *. During the first ten days he remained in bed from 10 p.m. to 10 a.m., taking during the day his ordinary exercise. During the second 10 days he went to bed at 10 p.m. as before, got up at 6 a.m., worked for two hours, and then went to bed again at 8 a.m. until 10 a.m. The work consisted in dragging a cart weighing 710 lb. 4 miles in two hours. Supposing the coefficient of traction to be the same as in walking, the amount of work cal- eulated by Haughton’s formula would be equal to about 100 tons lifted one foot. His weight at the commencement of the experiment was 146 lb. 2 oz.; it fell regularly during 10 days to 144 lb. 10 oz., viz. 1 lb. 8 oz. During the second 10 days it fell to 142 lb. 12 02., a loss of 1 lb. 14 oz. The following are the mean results in the first and second sections of 10 days. Mean amount of urine, in cub. centims. 6 A.M. 3 A.M. Io A.M. to to to Total. 8 A.M. TO A.M. 6 A.M. 1st section of 10 days ......... 71°65 100°4 1077°45 1249°5 2nd section of 10 days......... 75°6 35°8 1068°8 1229°4 There was a slight decrease in the urinary water in the two hours of rest following the two hours’ exercise. Mean amount in grammes of mercuric nitrate precipitate taken as urea. 6 to 8. 8 to Io. 10 to 6. Total. 1st section of io tee 3°056 usual exerciset ...... Ae 35°189 gece 2nd section of ro days, 2 hours additional 3°142 2°974 36°017 42°133 exercise from 6 to 8 * Count Wollowicz commenced these experiments with me, but was obliged to dis- continue them on account of the illness which eventually proved fatal. Serjeant Tur- ner, of the Army Hospital Corps, very carefully took most of the observations on the - temperature and the pulse. + One day’s urea from 6 to 10 a.m. is omitted as the urine was lost. 1871.] Effect of Diet &c. on Elimination of Nitrogen. 353 > The results show no diminution in the urea during the two hours of exercise; the slight increase may perhaps be disregarded. In the two hours of rest, there is equally inconsiderable increase after exercise; the excess in the 4 hours of the second section of 10 days was 1°58 gramme. In the next 20 hours there was an increase of ‘828 gramme, equal to 3864 gramme, or 6 grains of nitrogen. The differences are so small as probably to fall within the limit of error, and it is impossible to affirm that exercise to the amount of 100-foot tons in two hours made any alteration in the urea. Mean amount of nitrogen as determined by soda-lime. 6 to 8. 8 to Io. 10 to 6. Total. Ist section of 10 days*: rest from 6 to 10 ne a 7 aie 16°902 19°883 exercise from 6 to 8 A.M., 1°399 16°924 19°761 2nd section of so days: 1°438 rest from 8 to 10 A.M. ... The nitrogen by soda-lime showed very slight variations. There was a slight decrease in the 2 hours’ exercise and in the 2 hours’ rest after exer- cise over the corresponding period ; but it is so trifling that I hesitate to draw any conclusions. The figures show that the slight increase in the urea was, as supposed, an unavoidable error. Looking to the figures of the nitrogen by soda-lime as more correct, it seems that 2 hours’ additional exercise produced no marked change in the outflow when the inflow of nitrogen was constant. This result, as far as it goes, certainly bears out Voit’s assertion of the constancy of the nitrogen, but it does not destroy the conclusions formerly drawn that the nitrogen lessens during exercise and increases afterwards, because the amount of exercise was in the present case very much less ; and as the alteration in the nitrogen even in the former experiments, with much more severe exercise, fell within narrow limits, it might easily have been anticipated that work of only one-sixth the amount would be inappreciable. The method of experimenting also does not appear to me to be so good as that formerly used. Amount of nitrogen, in grammes, in the stools. Percentage composition. Amount in 24 hours. Solids. | Water. |Nitrogen.| Solids. | Water. |Nitrogen. 8th day of 1st period..| 217592 | 78°048 | 1°166 | 42°929 | 152°691 | 2°279 7th day of 2nd period.| 25:00 75°00 LA 2OvrtG Forgan in aaa * The nitrogen in the 2 first days is not included in the mean of the hours 6 to 10, as the urine was lost on one occasion, and on the other the experiment was uncertain. The mean of these hours (6 to 10) is therefore for 8 days. 354 = Dr. Parkes—Further Experiments on the [ Mar. 2, On the 8th day there was a large stool, showing previous accumulation. Taking the weight of all the stools during the two sections of 10 days, and using the percentage composition of nitrogen of the one day in each series, the mean daily excretion of nitrogen was 1°807 gramme in the Ist section, and 1:766 gramme in the 2nd section of 10 days. The pulse and the temperature of the axilla were taken every two hours from 6 a.m. to 10 p.m. ‘The temperature is in Fahr. degrees :— Mean pulse and temperature. First section of 10 days. Hours. | ours WEE 6. Saeaie MO. nl nae 2: 4. 6. 3. Of day EP See cre state Sie sates 64°6 |66°3 |67°8 |79°3 |65°5 |75 74°6 |74°2 169°5 | 70°65 Temp. of axilla...... 97°94 |98°04 98°32 |98°62 |98°32 (98°48 |98°49 [98°52 |98'41 | 98°32 Memyp. of mechuma —£. poe. Gone a eases OQi2 Mlteecres 99°27) setae 99°40 | ake 99°26 Second section of 10 days. (Additional exercise from 6 to 8 o’clock.) Hours. ours ne 6, ea ee OE Pe uiepe he ae 4. 6. | 8, IO. ote Puller. oie cee atied. 62°4 |82°2 |68'4 |76 [68 |74°4 |69 |69°9 |64°6 | 70°42 emp. ,ot-axalla 2.25.3. 98°24 198°24 |98°33 |98°23 |98°41 [98°45 |98°42 [93°44 |98°38 | 98°34 Sampson MECiIMUa || Neesee (O94: al sereee O0:2) scene QO32 24 ances 99°22) heeemer 99°26 The effect on the pulse of the exercise from 6 to 8 in the 2nd period was interesting. The exercise brought up the pulse 16 beats at 8 o’clock over the corresponding period ; but the pulse afterwards fell below the beats of the Ist period, and the result was a perfect balance of the day’s work, so that the mean pulse of the day was the same in both periods. This shows how completely the heart, if called on for exertion, compensates itself by subsequent rest. ‘The exercise made little difference in the temperature of axilla or rectum ; there was a slight rise at 8 a.m. corresponding with the pulse after exercise in both axilla and rectum, but the mean of the day was the same. SECOND SERIES. Prepared concentrated food. It was proposed to give prepared food of uniform composition, so that the daily ingress of nitrogen would be absolutely constant. I was unable to obtain the ‘‘ pea-sausage’”’ which the German troops are now using in the Field, and used instead a concentrated food which had been sent by an inventor to Sir Galbraith Logan, and by him sent to Netley for report. 1871.] Effect of Diet &c. on Elimination of Nitrogen. 355 It was composed of bread, meat, potatoes, sugar, spices and salt dried to- gether, &c., and was stated to contain everything necessary for nutrition, so that the troops on service would need no other food. It contained 13°65 per cent. of water and 2°73035 per cent. of nitrogen. After preliminary trials to know how much would satisfy hunger, 14 ounces were given daily, containing 10°838 grammes of nitrogen. The food, however, produced such derangement in nutrition (indigestion, heartburn, and headache) that after a few days the experiments were discontinued. In spite of the con- stant ingress, the elimination of nitrogen varied greatly from day to day, the extreme range being from 7'641 to 15°024 grammes; and the man felt so ill that he begged to discontinue the experiment. It was interesting to note that, in spite of the daily variations in the nitrogen, there passed out in the 5 days nearly the same quantity as entered, viz. 54°920 grammes of exit, as against 54°19 grammes of entrance. He lost weight during the trial. The experiment must be therefore repeated on some future occasion with other prepared food. Tuirp SERIES. Non-nitrogenous food. In the experiments formerly related in the ‘ Proceedings’ two men were kept for 2 days at a time without nitrogen. As it seemed to do no harm, the present experiments were now prolonged over 5 days on two occasions. The first was after the man had been well fed with nitrogen, the second after the body had become poor in nitrogen from the restricted supply given in the concentrated food. The non-nitrogenous food consisted of arrowroot, butter (deprived of casein), and lump sugar. Infusion of tea without milk was allowed, but this contained in the day only grain of nitrogen. Hunger was perfectly satisfied by this food ; the man felt quite well and could have continued it. The heartburn produced by the concen- trated food was at once relieved by this starch and fat diet. First Experiments on Non-nitrogenous Food. Previous daily entry of nitrogen=19.5 grammes. On the first day of non-nitrogenous food he took his ordinary exercise ; on the 2nd took additional exercise, which consisted in digging up potatoes over 576 square feet, lifting the weight (16 stone) into a barrow, and wheeling them home for 3 a mile. On the 3rd day he rested, on the 4th repeated the exercise, on the 5th rested. He did the 4th day’s work even better than the 2nd, and could have worked on the 5th day. The amount of work done cannot easily be calculated ; it was a good but not an excessive day’s work. The weight on the first day was 142 lb. 7 oz., and on the last 141 Ib. 10 oz. He took daily 60 fluid ounces of water (=1704 cub. centims. ), and as much arrowroot, oil of butter, and sugar as he liked. 356 Dr. Parkes—Further Experiments on the [Mar. 2, Urinary water, in cub. centims. 8 A.M. 3 P.M to to Total 3 P.M 3 AM ist day, usual work ......... 676°5 4.30 1106°5 2nd) day, CXErClse ....-cess-- 660 270 930 ard day, rest .......00s “onc3a9 780 210 990 Bila Gays CXCLCISS | ean anne AI5 37 502 5th day, rest ......:....-2e00es 705 140 850 Urea, in grammes. 8 A.M. 3 P.M to to Total 8 P.M 3 AM ist day, usual work ......... 16°768 8°514. 2.5°282 2nd day, CXELCISC seviercee.) jl mseepeemac 4°328 ee 6 25/ 4th day, marching ......... 2451 1°361 3°312 3°418 Binnday, TESt conse snes aenagaes 4°997 3°268 $°265 7465 The effect of the previous small entry of nitrogenous food is clearly seen ; on the Ist day the nitrogen fell almost to the amount of the 2nd day in the previous experiments. On the 3rd day, on the contrary, it was greater than on the corresponding day of the former series. The amount of nitrogen was actually greater on the 5th day than on the Ist. Except the excessive exercise of the 4th day, no other obvious cause existed for this elimination on the 5th day. No mistake seems possible ; for the urinary water on the 5th day was less in quantity than on the Ist, 2nd, and 3rd days, while the nitrogen was 2 grammes more than even on the 1st day after nitrogenous food was left off. An error in analysis is not possible, since not only were the analyses repeated, but the process by urea gave results corresponding to that by soda-lime. No constitutional condi- tion which could cause excess in elimination was indicated either by the pulse or body temperature, and the man felt perfectly well. I need hardly say that no nitrogenous food was taken; for it is quite certain that it was not. The increase in the 5th day in the Ist series, though less marked, is still unequivocal, and there seems therefore no rashness in stating that the con- clusion of the experiments formerly laid before the Society is affirmed, viz. that severe exercise causes an increase in the elimination of nitrogen in the period of rest after the exercise. It is noticeable that in this man the increased elimination was not in the hours immediately succeeding, but on the following day, and lasted for some time. Whether during the period of exercise the nitrogen was lessened is not so clear, as the fall from 4°323 grammes on the 3rd day to 3°812 on the Ath or exercise day might be merely the continuing effect of the depriva- tion of nitrogen. The experiments formerly recorded seem to me better adapted to determine this point, which, however, certainly requires more evidence in confirmation before it can be accepted. That changes go on in the muscles during exercise which lead to an increase in the outflow of nitrogen afterwards must, I think, be admitted ; and on this point it seems that the statement of Liebig must be supported against Voit. f It may be interesting to give the mean pulse and temperature during these days of non-nitrogenous feeding for comparison with the normal. oe i 1871.) Effect of Diet &e. on Elimination of Nitrogen. 359 During the day of exercise, however, the observations at 10 a.m. and 2 p.m. on the pulse and all the temperature observations on the marching day were lost, except at 8 a.m. and 8 p.m. On a diet without nitrogen. Mean pulse. Hours. Mean 8 A.M. |10 A.M.| 12 NOON.| 2 P.M.| 4 P.M.| 6 P.M.| 8 P.M. oy ist 5 days ...| 64°4 |/69°6 | 692 | 73°6 | 70O°2 | 75°38 | 72°6 | 70°77 and 5 days...| 68 HOG Wee 752 7 74. 75°60 1972°6),| 72205 Mean temperature of axilla. Hours. las SE Be he hs et Se Mean by day. 6 A.M.| 8 A.M. |10 A.M.| 12 NOON.| 2 P.M.| 4 P.M.| 6 P.M.| 8 P.M. y cay 1st 5 days ...| 98°08 | 98°16 | 98°36 | 98°36 | 98°32 | 98°32 | 98°36 | 98°36 | 98-29. and 5 Gays...] ss... g8'08 | 9815 | 98°25 | 982 | 9815 | 985 | 98°15 | 98°16 Mean temperature of rectum. Hours. gel Mean 8 A.M. |IO A.M.| 12 NOON.| 2 P.M.| 4 P.M.| 6 P.M.| 8 P.M. OF days. ash.6) days ...|.99:0. | '..290. GOP on Neots [QO ieee 3 >» os Om aia 6th - 99 + «> Ouse “th * iy ..-. 0°1500 8th 5 Se . «xO 9th > 3 + oe OZT2e 10th = vo ne ORES Mean... oc... 20 Sa list day, Hon-nitrozenous food - od). ws 2 ad ee 0°0750 2nd oe Ss mas, wah, Sqeirein 3h Ghee see meee: Aaa tape eee 0:0810 ord 9 Fy a Nt aia rrilavsuct omeye te Conca dcue cannes 0°1250 4th ~ bo Edn iainsPaes 2 cea hens SN Ro ihe 0:0761 5th 3 ) <8) ere 'a'6 Slatyra ce a's 5» Saher Mean. 0.020020. 0.5 2 Oem With an equal pressure the lever was thrown almost double the height when the man was on nitrogenous food. This feebleness of expansion shown by the sphygmograph was quite in accordance with the impression given to the finger. The softness of the pulse proved it was not owing to in- creased resistance of the arterial wall. ‘ With regard to the temperature, the means are so close to those of the days on ordinary diet, that having regard to the fact that the period was shorter and therefore more liable to error, and that some observations were omitted on the marching-day, it may be concluded that a non-nitrogenous diet continued for 5 days neither raised nor lowered the temperature of the axilla and rectum. It therefore appears that when the nitrogenous food of a healthy man was reduced to one half for 5 days, and he was then kept for 5 days more without nitrogen, he was able on the 4th day after such deprivation to do a very hard day’s work. The non-nitrogenous diet, consisting of butter oil, starch, and sugar, kept him perfectly well; all functions seemed natural, the tem- perature of the body was unaltered, the pulse became very soft, and the sphygmographic tracings showed very feeble markings ; but it was not ma- terially altered in frequency. The circulation appeared to be properly carried on, as far as could be judged of by the man’s own feelings. The health, as judged of by the man’s feelings and the absence of objective signs, was perfect. On account, however, of the feebleness of the heart’s 1871.] Captain Belavenetz-—Magnetic Observations, &c. 361 action it was not thought right to continue the experiments, which had, I believe, sufficiently proved that force necessary for great muscular work can be obtained by the muscles from fat and starch, though changes in the nitrogenous constituents of the muscles also go on which have as one effect an increased though not excessive elimination of nitrogen after the cessation of the work. II. “ Magnetic Observations made during a Voyage to the North of Europe and the Coasts of the Arctic Sea in the Summer of 1870.” By Capt. Ivan Betavenerz, I.R.N., Director of the Imperial Magnetic Observatory, Cronstadt. In a Letter to ArcHIBALD SmitH, M.A., LL.D., F.R.S. Communicated by Mr. Smiru. Received February 4, 1871. Dear Frienp,—Last summer I made a very interesting magnetic voyage, being invited by Vice-Admiral Possiet to take part in the Arctic Expedition with the Grand Duke Alexis, Lieutenant of the Navy. The first part of the voyage, from St. Petersburgh to Arkangeslsk (1179 miles), by rivers and lakes, I made in a little screw cutter, 273 feet long, 7z feet wide, and 23 feet deep, belonging to the corvette ‘ Variage;” the second part of the voyage (1716 miles) in the schooner ‘ Sextant.’ I visited the White Sea and the coasts of the Arctic Ocean ; the end of the voyage was in the clipper ‘ Jemchug’ (2461 miles), from Norway to Cronstadt. On the way I made magnetic observations, the result of which I inclose in this letter. I will ask you to make them known to General Sabine and to the Royal Society. The observations were made by a small compass which has the edge needle, and which is able to turn from one side to the other. Each ob- servation, the data of which are given, was made in different directions of the instrument, turning the instrument on 120° in azimuth, by which the eccentric errors were taken off. In each direction the needle was turned on both sides for correcting the error of the magnetic direction in the needle. Four observations were made for each position of the needle. By this mode of observation the error does not exceed more than +1). In the declination table are given the day and the hour of each observa- tion in order to judge of the daily disturbances of magnetism. It would be very interesting to compare these observations with those made at the same time by photography at Kew, and thereby to deduce the magnetic disturb- ance due to the change of magnetic latitude. The inclination was observed by a Kew Inclinometer belonging to the Compass Observatory, made in London in 1865, and examined by Mr. Balfour Stewart. No doubt it is the most useful instrument for this kind of observation. The horizontal force was observed by ‘‘ Captain Belavenetz’s Instrument 362 - Captain Belavenetz—Magnetic Observations _[ Mar. 2, DECLINATION. PLACE OF OBSERVATION. Month Hour of Obser ved Mean Month and Day. Observation. Declina- | Declina- | and Day. tion. tion. h m h m [e) 4 (eo) 1 SHLISSELBURG (town). 31 May Lat. 59° 56! 38” N. 12 June Long. 31° |’ 59" E. from perce csnsn | seceesccscccsesesccce | seresecsseae | sesessversee Greenwich. : LoprsnseE Pou (town). 3 3 Lat. 60° 44' 11'-8 N. 15 June | 5 Oto 5 30 p.m. 1 22°70 Be 2 15 June Long. 33° 33’ 8 E. Virrcra (town). a June | 8 80to 9 Oam. | 2 14:5 EB. Lat. 61° 0' 23'-4 N. 7 Long. 36° 27' 1'"-4 E. {9 June 2 0, 8 30 "5, | 2 134 3 8 = 5p June | 90, 9 304.1 2408 ip ae 3 2 SoaBy 5p June | 930,10 0 ,, | 2118 _ June 7 ! 19 June 6130 sy 70 pnw, 2 18 F dune i 10 1 BOE Sa el ooeee ene ae Vouoepa (town). a7 June 10 Oto 10 30 a.m.| 3 17-6 B. Tat. 59° 13' 30'-9 N. Long. 39° 52’ 59'-7 BE. » » (1030, 11 0 , | 3 220 Sc ial LO} all oO Gri eleogecee 14 Oo aie. 11 30 ” 12 O noon 3 23°4 56 June mo | 4 0, 4 30 pan. ind oom 3 248H.],, ,, ; 16 3 26: pe fe ? 4 30 9 5 0 3 69 98 3) 33 7 0, 7 80am.| 3 256 Pe 80, / 28 30. 4) ead a9) aas3 9 0 ” LOVED ” 3 24°5 E. Veixy Oostue (town). 19 June 5 Oto 5 45pm.| 6 5585. Lat, 60° 45' 45'-6 N. aoe 19 June Long. 46° 17’ 59'"2. KE, 3 duly 1 AD);, So Oam. (7038 1 July 19 June 7 88E Riprive mii wre lea Pa 21 June K Se 8 0, 845am.| 717-78. PIANDA (village). 24. June 24. June ! ' = ee eres 5 : E Lat. 62° 56’ 11" N. 6 auly 415to 5 Oam.| 4 57-25. | 4 57-28, 6 July Long. 42° 35' 8'"3 EH. 1871.] INCLINATION. hm 3 30 to 7 Oto S © ., 7 20 ,, 7 30 to 5 20 ., 7 45 ,, 6 20 ,, Hour of Observation. hm 4 30 p.m. 11 Otoll 15 am. Pea. 1) 50 ,, oA), 11:35. ,, 11 50 ,, 12 10 noon 7 20 p.m. S20" ,, 8 0 ” 10 45 ,, 11 80 a.m. 7 45 am. & 400: 8 30 ” 5 30to 6 15am 7 15 ” Observed Inclina- tion. 9° i 70 36°7 72 59-4 made during an Arctic Voyage. Mean Inclina- tion. 71 33°5 72 58-9 Month. | Day. a ee Hour of ation. Hori- | Verti- zontal| cal Force. | Force. 1-6328) 4-6478 4-7985 4:9259| 9-97 1:5826) 47460 1:6839 1:6109} 4-8924 hm May 31 zs Wane Pp 5 30 p.m. 3 June ib 8 O pm June 4 | 12 30 p-m. 19 June 15 9 0 am. June 20 10 O am. July 2 1100 am. June 24 5-0029} 10°85 5:0305] 10°91 5-1508} 11:17 vat ta ee ee 364 Captain Belavenetz—Magnetic Observations _[ Mar. 2, DECLINATION. No. PLACE OF OBSERVATION . Month Hour of Observed Mean Mionils and Day. Observation. Declina- | Declina- [ng Day. tion. tion. Oe ee eee ve hm hm 2 a BS cp 7. | ARHANGELSK (town). 26 June Lat, 64° 32! 10''8 N. i aiily 1l Otoll 40a.m.| 5 53:5 BR. 26 June Long. 40° 31' 63 E. oi Ni 7 15 i g 10 s 5 49:8 5 44.7 E. je July | 28 te 39 io 9 30 ,, 10 15pm. | 5 309 E. Po ieee ee eon a Se 8. ay (Monastery on an Fe July | 7018 8 One| ol ened Hiat:-o9°. 1 22" N: teat 12 15 2 265 Long. 35° 44’ 44" B. pray sonia Wea) 2 aes 9 89 2 45 9 3 45 p-m. 2 20-4 ie eae 7) O05, - 4% 80, 1 eel iy 650 ,, 7 30am. |-2 396 99 59 Sic 3 20 ,, 4 0 pm| 2otoy 5 17 ” ” 99 7 40 ” 8 15 93 2 24:4 9 28-0 B. 7 6 %9 99 ig” 9 30.,, 10 15am: |72' 385 Ke 39 99 39 L 20 33 8 0 p.m. 9 90-9 19 = m5 4702 8 Oam, 2 380 ap ik 11 40 ,, 12 10 noon} 2 24-6 beer 3d 20 ,, 4:70 p.m: | 2134 999 6 0 9 6 45— ” 2 27:2 E. 9. | Car. Kanine Nos. 10 Ae a 1 Lat. 68° 39’ 12" N. 22 July | 4 20to 5 15pm.|8 58 E. Pie a3 July ee sa > (10:30, 11 ib am. 8 | 2omee Bie 10. Svraroy Nos (Cap.). Lat. 68° 9' 50" N. 14 Te Fuly 11090042 So nope lee een 96 July Long. 39° 47' 50" E. OG Y noon -|4 83H. en EE EE 11, |Brestimennos (island). 13 ae 11 0 to,t2 50 : Lat. 68° 4' 4” N. DD July 0 noon) 5 25-7 E. Long. 39° 34' 46" E. ae 5 0, 5 45pm. 5 359 14 13 % 8 0 9 8 45 ” 5 40:8 = July 15 5 41-1 E. a» 8 30, 8 50am.| 5 59-4 » » 112380 ,, 2) 15 pan) > 458 oe bP) 3 410 9) 4 10 ” 5 47-6 Be made during an Arctic Voyage. INCLINATION. Z : Force Hour of Hori- | Verti- Total | in Month. | Day. Observation. zontal | _cal Force. |British Hour of Observed) Mean Force. | Force. Unit Observation. Inclina- | Inclina- nits. tion. tion. hm hm pee, i ey 73.507 | 2eme | 28 | 8 O am, |1-4283 4-9307 |5-1384 | 11-13 P20) 200 ,, |73 463 July 10 8 30to 9 15am.|73 41-4 24155, 10 0 , |73 448 5 50,, 6 45pm. | 73 486 July £ 10°30) acm. Fr. AIR -QQr F F 645, 730 , |73 41-4 73 45-1 7 mae 14268 |4:8957 (50993 | 11-06 9 19 ears w15.,, 10 Oam. | 73 473 nm 0, 1030 ,, |73 47:0 ~20to 8 l5am.|7%76 7-2 al 12 20to 1 Op.m.|75 485 15 47-6 m0, 140 ,, |75 466 13 9 30 to 10 15 a.m. |75 50-2 og | 12 15 pam. 75 535} July | 15 1-2653 |5-0343 |5°1908 | 11-26 1015,, 1050 ,, |75 568 me ed pan. VOL. XIX. | 2F 366 Captain Belaveneta— Magnetic Observations [ Mar. 2, | DECLINATION. No. PLACE OF OBSERVATION. ie aac iii 1 - =~ Month ’ Hour of Observed Mean Month and Day. Observation. Declina- | Declina- ang Day. tion. tion. hm hm ona es 4 12. | TerrperskasA Goosa (gulf). {17 aa oll 1 581E Lat. 69° 10’ 50" N, eas acts =u July Long. oD” 9' 45" FE. a eae 12 30 = it 155 p-m. 1 52:3 29 1 - (SB 15 4? 8 45 4, 02> 3:9 eee x oat | 080-5, 26 Ie prea aes yo) 80 = BAS 8 ieee na ies Kona (town). 19 : az Jul 1 303 E Lat. 68° 52! 48" N. BEY a 20 te, Oem Long. 33° 0' 17" E. ah wale ROP Ll 50 elec ay Jul yl 310), 8 20 pearls! a bat aD WO, 045 gral age ae 20 July Chae) Tee 8 30, 910 am./ 1 34-7 20 July D 11 30 ,, 12 10 p.m.| 1 246 1 Aug ss as peg) SO gone Were al image gaan 9 9 9) 40 99 6 10 bP) 1 5 1 E ha Varp'okE (town in Norway). 24 July | , Lat. 70° 22! 16" N. aaa: 3 45to 4 15pm.| 0 234W Dene eee OL ee 2b My || 9 79 4h nam. oes 6 Aug de ; ap) (ll 30 | 12. Omeon) 0) 20% 25 July 6 A » » ~=©(12 50,, 120pm.}0275 | 0 253w.|°? 778 9” 3 10 » & 40 ” 0 22:2 et » ») DADs, BD Ape; lOrao® » pi | f 10, 140.) 0 40:0 15. | Hammerrzsr (town). 30 July ett Deis, ee 30 July Lat. 70° 40' 11” N. IT dug. 7 9%.) 30pm. | 6 120 Long. 23° 42' 0" E. Boy 330, 410, |6110W : ae 16. | TRroms'ox (town). 1 Ree mk rae A Lat. 69° 56! 3" N. Tg Aug. | 9 15to 9 45 am. |10 54-6 W. Long. 18° 8' 0" E. » | [1d 30 5,012) Omoonitl 10-9 59 an 199 1.0 ” 1 30 p.m. il 8:4 11 -Dyaave ” 90 a, wc: SIU ahs, 1l 36 1 13 Aug. 9 9 2 jzAug. | 915,10 Oam.|l1 00W. 1871.] made during an Arctic Voyage. 367 INCLINATION. Hone of Hori- | Verti- Total ere Elo oe Observed| | Mean: Month. | Day. Observation. ae ee Force. British Observation. Inclina- | Inclina- Units. tion. tion. a 2 aa 10 Oto 10 45 am. | 76 23°4 md, 11 30 ,, | 76 25-2 7 1 76 202 | Tuly | 55 | 12 15 p.m. [1-217 5-091 /5-1550| 11-18 415, 5 Opm.|76 177 D0, 530 , |76 19-4 9 30 to 10 10 am. | 75 40:0 1010,, 11 0 ,, |75 400 6 0,, 6 45pm.|75 403 July = 1 30 pm. 75 40-1 | 1-2611 |4-9361 |5-0946 | 11-05 645, 715 ,, |75 383 ‘| July | 20 Aug. 7 «| «12:80 pm. 915 ,, 10 10 am. | 75 39:5 10 10,, 1040 ,, |75 42-4 9 50 to 10 45 am. | 76 43-1 ms (8 Face “2 | 12 15 p.m. {11885 [5 0247 [5-1628 | 11-20 10 Otoll Oam.!76 46:2 | 76 45:1 = SP | 12 15 pam. |1-1720 /4-9780 [5-141 | 11-09 Il 0O,, 12 O noon! 76 44:0 : 10 Otoll Oam.|76 24-4 ; 76 227) Aug. | zs | 12 15 p.m. |1-2098 /4-9925 |5-1369 | 11-14 Seo, 11 30 ,, 176 211 = 368 Rev. S. J. Perry on Magnetic [Mar. 9, of Vibration,”’ by which I made all my observations on the submarine boat and on armour-plated ships. In this instrument the needle is 3-2 inches long and 0°17 inch in breadth. The magnet is suspended on a silk thread and vibrates in a wooden box, on the side of which there are the divisions in degrees to mark the angles formed by the turning-needle ; for each observation I counted 700 vibra- tions. I found that for such a voyage this instrument answers the purpose. The exact drawing of this instrument you will find in my book on the «* Submarine Boat,” 1867, Plate VI. Drawings 6 and 8 give half the size of the instrument, and drawing 7 the full size of the needle. I know that General Sabine and the Royal Society are much interested now in the Northern Magnetic Observations, so I hastened to send the results to you, as I know that they cannot be printed soon in Russian. I remain, your attached friend, JoHN BELAVENETZ. Cronstadt, = November, 1870. March 9, 1871. General Sir EDWARD SABINH, K.C.B., President, in the Chair. The following communications were read :-— I, “Results of Seven Years’ Observations of the Dip and Hori- zontal Force at Stonyhurst College Observatory, from April 1863 to March 1870.” By the Rev. S. J. Perry. Communi- cated by the President. Received January 23, 1871. (Abstract.) The object of the present paper is to bring further evidence to bear upon an important question of terrestrial magnetism. The existence of a sensible semiannual inequality in the earth’s mag- netic elements, dependent on the position of the sun in the ecliptic, was deduced by General Sir Edward Sabine from a discussion in 1863 of a continuous series of the monthly magnetic observations taken at Kew. A previous reduction of observations made at Hobarton and at Toronto had first suggested the idea, and a new confirmation of the results has lately been obtained by Dr. Balfour Stewart from subjecting a second series of Kew observations to the same tests as before. The observations, which form the basis of the present discussion, extend over the period from March 1863 to February 1870, during which time the same instruments have been in constant use. These are a Jones unifilar and a dip-cirele by Barrow, both tested at Kew, and a Frodsham chronometer. Sir Edward Sabine, who made the Stonyhurst Observatory one of his magnetic stations 1871.] Observations at Stonyhurst College Observatory. 369 in the English survey in 1858, greatly encouraged the undertaking of monthly magnetic observations, and the Rev. A. Weld procured in conse- quence the instruments still in use. Only occasional observations were made with these instruments for some years, and it was only in 1863 that a continuous series of monthly determinations of the magnetic elements was started by the Rev. W. Sidgreaves. He observed regularly until Sep- tember 1868, when I returned to my former post at the Observatory, and I have continued the same work ever since. A stone pillar was at first erected for the magnetic instruments in the open garden, and this remained in use from 1858 until the beginning of 1868, when a most convenient hut of glass and wood was built for the in- struments in a retired corner of the College garden. This alteration was rendered necessary from the placing of iron rails in the vicinity of the old pillar; and although it introduces into the results a correction for change of station, it has the great advantage of securing immunity from dis- turbance for the future. Considering the object in view in drawing up this reduced form of the dip and horizontal-force observations, I have judged it advisable to adhere strictly to the tabular forms in which the matter has been presented in previous discussions of a similar nature. Each element is the subject matter of these tables. In the first are the monthly values of the element, the deduced mean value, and its secular variation. Next in order comes the calculation of the semiannual inequality. The residual errors, and consequent probable weights of the observations and results, compose the third and last Table. The yearly mean values of the horizontal force are found to vary pro- gressively from 3°5926 to 3°6178 in British units, the mean for Oct. Ist, 1866, being 3°6034, with a secular acceleration of 0:0042. Calculating from the monthly Tables the mean value of the horizontal force for the six months from April to September, and for the semiannual period from October to March, we find the former to be 0°0005 in excess over the latter, showing that this component of the intensity is greater during the summer than during the winter months. Treating the dip observations in a precisely similar way, we obtain 69° 45’ 21” as the mean value of this element for October Ist, 1866, subject to a secular diminution of 1’ 49'"2; the extreme yearly means being 69° 48’ 47” and 69° 37'52". The result- ing excess of 10” for the winter months in the computed semiannual means is so small, that the observations tend mainly to show that the effect of the sun’s position is not clearly manifested by any decided varia- tion in the dip. Deducing the intensity from the above elements, we obtain for the summer months the value 10°4136, whilst that for the winter months is 10°4128. The intensity of the earth’s magnetic force would thus appear to increase with the sun’s distance, but the difference is not large enough to have more than a negative weight in the question under discussion. This weight, moreover, is lessened by the slight uncer- 370 Production of Olefines from Paraffin. [ Mar. 9, tainty arising from the probable disturbing causes at the first magnetic station. It is hoped that a second series of observations at the new station will throw greater light on the fact of the sun’s influence on terrestrial mag- netism, by either confirming the results obtained above, or by adding fresh weight to the conclusions arrived at by the President of the Royal Society. II. “Preliminary Notice on the Production of the Olefines from Paraffin by Distillation under Pressure.” By T. EH. Toorpz, Ph.D., Professor of Chemistry in Anderson’s University, Glasgow, and Joun Youne. Communicated by Professor Roscoz, F.R.S. Received February 2, 1871. When paraffin is exposed to a high temperature in a closed vessel, it is almost completely resolved, with the evolution of but little gas, into hydrocarbons which remain liquid at the ordinary temperature. This reaction will undoubtedly afford the most important insight into the constitution of this body. Accordingly we have-repeated this conversion on a large scale, and from about 33 kilograms of paraffin melting at 44°°5C. (prepared from shale) we have obtained nearly four litres of liquid hydrocarbons. This mixture of hydrocarbons commences to boil at about 18° C., but the quantity coming over below 100° C. is comparatively small; by far the greater portion boils between 200° and 300°. A preliminary separation shows that the four litres are made up of hydrocarbons boiling litres Between: 200° and 300°)... 32 Sa ee ee ee D7, 500° amd42000s gas DAIS 1 ORE 1:0 Below 1O0Cf 2 7A RLRE OSM. Oa eS 0°3 4:0 Up to the present we have principally occupied ourselves with the investi- gation of the fraction boiling below 100°, and have obtained conclusive evidence that it is mainly composed of olefines, the proportion of members of the C, H,,+2 series being but small. By repeated fractionations over sodium we obtained perfectly colourless liquids boiling about 35° and 65°, which were attacked by bromine in the cold with the greatest energy. On adding the bromine slowly and in minute drops, and carefully cooling the hydrocarbon by a mixture of snow and salt, scarcely a trace of hydro- bromic acid was produced. The portion boiling at 36° may be either amylhydride or amylene, or a mixture of both; the avidity with which the bromine combines with it shows that the latter body must be present in considerable quantity. As soon as the drops of bromine permanently 1871.] On the History of the Opium Alkaloids. 371 coloured the liquid, it was submitted to distillation. Only a small portion came over below 40°; the thermometer rose rapidly to 180°, and nearly the whole of the bromine-compound distilled at 184° to 188°. This sub- stance is amylene bromide, C, H,, Br, ; Wurtz gives the boiling-point of this body at about 150°. The portion therefore boiling at 35° is mainly amylene. Exactly similar results were obtained from the portion boiling at 65° to 70°. This, from its boiling-point, may be either C, H,, or C, H,,, or a mixture of both. Bromine disappears instantly on adding it to the care- fully cooled liquid, and on distillation by far the greater portion is found to have combined with the halogen. The bromide thus obtained distils with slight decomposition about 195°. Pelouze and Cahours found that hexylene bromide, C, H,, Br,, boiled at 192° to 198°. We are at present engaged in the further investigation of this subject, and hope shortly to lay our results before the Royal Society. III. “Contributions to the History of the Opium Alkaloids. Part I.—On the Action of Hydrobromic Acid on Codeia.” By C. R. A. Wricut, D.Sc. Communicated by Professor Roscor F.R.S. Received February 6, 1871. It has been shown by the late Dr. A. Matthiessen, in conjunction with the writer *, that when codeia is heated with a large excess of strong hy- drochloric acid the following reactions successively take place :— Codeia. Chlorocodide. C,, H,, NO,+ HCI=H,0+C,, H,, Cl NO,. Chlorocodide. Apomorphia. C,, H,, C1NO,=CH, Cl+C,, H,, NO,. It appeared of interest to examine the action of hydrobromic acid under similar circumstances, and for this purpose Messrs. Macfarlane, of Edin- burgh, with their wonted liberality, put a considerable quantity of pure codeia at the writer’s disposal. The aqueous hydrobromic acid employed was obtained by the action of H1,S on Br in presence of water, and subsequent rectification over pulver- ized K Br; it was free from SO, H, and other sulphur compounds, had a sp. gr. of about 1:5, and contained about 48 per cent. of H Br. When codeia is heated with from three to six fimes its weight of this acid, either on a water-bath or to gentle ebullition over a flame, the liquid, which at first produces no precipitate with solution of carbonate of soda, ‘gradually darkens in colour, and acquires the property of yielding a dense white precipitate with this reagent. No appreciable quantity of methyl * Proc. Roy. Soc. vols. xvii. p. 460, xviii. p. 83. 372 Dr. C. R. A. Wright on the [Mar. 9, bromide is evolved during the first stages of this change, but subsequently this body is produced in some little quantity. The precipitate thrown down by carbonate of soda before this further change ensues, appears to consist of a variable mixture of at least three substances, two of which are readily soluble in ether, while the third is but sparingly soluble in that menstruum ; all are bases, the one insoluble in ether, and one of those soluble containing bromine: the one apparently first formed is produced by a reaction precisely analogous to that whereby chloro- codide is generated, viz.— | Codeia. Bromocodide, C,, H,, NO, +H Br=H, O+C,, H,, Br NO,, and is therefore termed bromocodide ; this base appears to be acted on further with great ease, giving rise ultimately to the other two, the first of which has the constitution of codeia less one equivalent of oxygen, or C H,, NO., and is therefore provisionally named Deoxycodeia; whilst the second has the composition of four molecules of codeia coalesced together, one of the 84H atoms in the product being replaced by Br; itis therefore provisionally termed Bromotetracodeia, the simplest mode of representing the simultaneous formation of these two bases being as follows :— Bromocodide. Codeia. Deoxycodeia. Bromotetracodeia. C,, H,, Br NO,+4C,, H,, NO,=C,, H,, NO,+C,, H,, Br N, O.,. Owing to the ease with which bromocodide is altered, it is a matter of some difficulty to obtain it in even an approximately pure condition, as the complete separation of deoxycodeia appears impracticable when this base has once been produced. The product of the action of three parts 48 per cent. acid on one part codeia on the water-bath for from one to two hours is precipitated by excess of sodium carbonate and the precipitate collected on filters; unaltered codeia is for the most part separated thus, being contained in the filtrate. Extraction ofthe mass with ether and agitation of the ethereal solution with HBr furnishes crude bromocodide hydrobromate, which may be purified by a repetition of the process, frac- tional precipitation being resorted to to get rid of traces of colouring- matters: the purified hydrobromate thus obtained was a viscid colourless liquid which utterly refused to crystallize, and dried up to a gum-like mass over SO, H,. Dried at 100°, the powdered gum gave these numbers *:— 0°3500 grm. gave 0°6340 CO, and 0°1580 H, O. 0°230 grm, boiled with NO, H and Ag NO, gave 0°1900 Ag Br. * All combustions given in this paper were made with lead chromate and finished in ° a stream of dry oxygen. 1871.] History of the Opium Alkaloids. 373 Calculated. Found. er ea 2 Fes aaa €,, 216 48°76 49-40 ci a ae a 4:74 501 pee ee” S612 85-08 kes 14 3:16 mms St Es Ng9 7°22 @-e Be NO.HBr ...:.. 443 100-00 The slight excess of carbon and deficiency in bromine thus found are doubtless due to the presence of a little deoxycodeia, the hydrobromate of which requires 59°34 per cent. carbon and 21:98 per cent. Br. Another specimen of bromocodide hydrobromate, prepared as above from the pro- duct of three hours’ digestion at 100° of one part codeia and three parts 48 per cent. HBr, yielded numbers indicating 51°6 per cent. carbon, 5:3 and 33:4 per cent. Br; whilst a repetition of the purification process scarcely altered the numbers. Owing to the great difficulty in preparing the pure salt in quantity, no attempt to isolate and analyze the base itself was made, the more so that the precipitate thrown down by carbo- nate of soda from the pure hydrobromate appeared to tally in every respect with the chlorocodide formerly examined ; their qualitative reactions, too, are identical. The crude bromocodide hydrobromate obtained after five or six hours’ digestion of codeia with from three to five times its weight of 48 per cent. HBr deposited, on standing for some days, crystals not readily soluble in cold water ; recrystallized several times from boiling water, minute snow-white crystals were ultimately obtained; these slightly darkened on drying over SO, H,, and more so at 100° and gave the following numbers on ana- lysis :— 0'3565 grm. gave 0°7760 CO, and 0°1960 H, O. 0°3245 grm. gave 0°7045 CO, and 0°1790 H, O. 02200 grm. burnt with’ soda-lime gave 0°0570 Pt. 01380 grm. boiled with NO, Hand Ag NO, gave 0°0700 AgBr. These numbers agree with those calculated for deoxycodeia hydrobro- mate, as the following comparison shows :— Calculated. Found. ae ue 56 4°20 | US Means 4 EY DPN Ho} . Me eta hte Ge ovatarmnt tiie 39°D 2°66 ties 2 2°64 ee ee ——_—_ ——— C,, H,, CIN, 0,,+0,, 1334-5 100-00 In all its physical and chemical properties chlorotetracodeia closely re- sembles bromotetracodeia: their qualitative reactions are identical; they have an intense bitter taste and apparently but slight physiological action, at any rate in small doses. My thanks are due to Mr. J. L. Bell, in whose laboratory the above ex- periments were carried out. 1871.] Dr. A. Giinther’s Description of Ceratodus. 377 March 16, 1871. General Sr EDWARD SABINE, K.C.B., President, in the Chair. The following communicatious were read :-— I. “ Description of Ceratodus, a genus of Ganoid Fishes, recently discovered in rivers of Queensland, Australia.” By ALsert Gintuer, M.A., Ph.D., M.D., F.R.S. Received February 7, 1871. 7 (Abstract.) After some introductory remarks the author proceeds to give a descrip- tion of the external characters which appear to indicate the existence of two species, viz. Ceratodus forsteri, with fewer and larger, and Ceratodus miolepis with smaller and more numerous scales. The microscopical structure of the scales and teeth is treated of in two separate chapters, the latter being compared with the fossils from the Triassic and Jurassic forma- tions, and found to be identical. The resemblance to the dentition of Protopterus, Psammodus, Dipterus and other fossil genera is pointed out. The skeleton resembles in its general characters, as well as in numerous points of detail, so much that of Lepidosiren, that from this part alone the conclusion must be drawn that these genera belong to the same natural group of fishes. It is notochordal, all its parts having a cartilaginous basis, more or less incompletely covered by thin osseous lamellee. The ossifications of the skull are but few in number, and may be desig- nated thus :—ethmoid; a pair of frontals separated by a single “ sclero- parietal’; basal, with a tooth-bearing pterygo-palatine on each side, the latter bones being suturally united in front; vomer cartilaginous, tooth- bearing. Mazillary and intermawillary elements are not developed, re- placed by facial cartilages which are confluent with the suborbital ring, all these parts being cavernous. Tympanic pedicle cartilaginous, with ossified lamella (os guadratum) and double condyle. Mandible with an articulary and dentary lamella. Preoperculum a rudimentary moveable cartilage. A well-developed operculum and styliform suboperculum. Hyoid arch more complex than in Lepidosiren, consisting of a pair of ceratohyals, a basi- and glosso-hyal. Branchial apparatus composed of five arches, of which the last is rudimentary ; not differing from the Teleosteous type, but car- tilaginous. In a vertical section of the head the parts of the brain-cavity and of the acoustic cavity (which is entirely enclosed in the skull) are explained. A pituitary gland is present. The notochord forms the base for about 68 sets of apophyses, 27 of which bear ribs. The various modifications in the different parts of the column are described in detail; and more especially attention is directed to the first rib, which is very similar to that of Lepidosiren, where, from its more intimate connexion with the skull, it was interpreted in various 378 Dr. A. Giinther’s Description of Ceratodus. [ Mar. 16, ways, for instance by Mr. Parker as the “ large first pharyngo-branchial.” Arrangement and detachment of dermoneurals as in Lepidosiren. The scapular arch and pelvis are more developed than, but typically entirely identical with, those of Lepidosiren. The paddles are supported by a cartilaginous axial skeleton, that is, by a longitudinal series of joints, with lateral divergent articulated branches, each joint having two of these branches. The relations of this singular structure to the corresponding parts in Lepidosiren and Selachians are explained ; and there is no doubt that the Ganoids of the Devonian epoch, with acutely lobate fins, had their paddles supported by a similar internal skeleton. Eye without falciform process or choroid gland. Heart.—TYhe arrangements of the interior of the ventricle and single atrium, and the external appearance of the bulbus arteriosus, are very similar to the same parts in Lepidosiren ; but the valvular arrangement of the bulbus is more “ Ganoid,” though considerably modified. We find at a short distance from the origin of the bulbus, first, a single, cartilaginous, papillary valve worked by a special muscle, then a transverse series of four small short valves (sometimes reduced to papille), then a transverse series of four oblong raised strips (rudimentary valves), finally a transverse series of four well-developed ‘‘ Ganoid’’ valves. Four arcus aorte enter the four gills, without sending off branches, and four vene branchiales are collected into the aorta descendens. A description of the principal portions of the circulatory system follows. The gills are completely developed, four in number, lamellated. The pseudobranchia does not receive its blood from the heart ; thus an “ oper- cular gill”’ is absent as well as spiracles. The Jung is single, but its cavity divided into two symmetrical halves, each with about thirty cellular compartments; pneumatic duct and glottis as in Lepidosiren; its dorsal artery is a branch of the 4. celaca; and its vein enters the atrium separately from the sinus venosus. The most important points of the structure of the remaining soft organs are the following:—the intestinal tract is perfectly straight and very wide, with a complete spiral valve, along the axis of which large glands are imbedded ; the stomach is indicated only by a shallow double pyloric fold; there are no pyloric appendages, but a glandular mass appears to represent the spleen. Not only the liver, but also the paired, lobed kidneys are provided with a portal system. The two ureters enter by a single opening a small urinal cloaca situated at, and partly confluent with, the back of the rectum. Testicles without developed vas deferens, which appears to be represented by a blind duct, traversing the interior of the testicle, and receiving the semen from the canaliculi seminiferi. Ovaries transversely laminate, the laminze being the bearers of the stroma in which very small ova are developed ; the ova fall into the abdominal cavity, and are expelled by a pair of wide peritoneal slits behind the vent. But there 1871.] Dr. A. Giinther’s Description of Ceratodus. 379 are also a pair of narrow oviducts, with or without a narrow peritoneal opening, each confluent with the ureter of its side. In the concluding chapters it is shown :— 1. That Ceratodus and Lepidosiren (Protopterus) are more nearly allied to each other than to any third living fish, that they are well-marked modifications of the same (Dipnoous) type, the latter genus diverging more towards the Amphibians than the former. 2. That the difference in the arrangement of the valves of the bulbus arteriosus cannot longer be considered of sufficient importance to distin- guish the Dipnoi as a subclass from the Ganoidei; but that the Dipnor may be retained as a suborder of Ganovdei. 3. That the suborder Dipnoi may be characterized as Ganoids with the nostrils within the mouth, with paddles supported by an axial skeleton, with lungs and gills and notochordal skeleton, and without branchio- stegals. ‘4. That a comparison of Teleostei, Chondropterygii, and Ganoidei shows that the two latter divisions, hitherto regarded as subclasses, are much more nearly allied to each other than to the Teleostei, which were deve- loped in much more recent epochs; and therefore that they should be united into one subclass—Paleichthyes—characterized thus: heart with a contractile bulbus arteriosus ; intestine with a spiral valve; optic nerves non-decussating. 5. That there is very strong evidence that the suborder Dipnoi was re- presented in the Devonian and Carboniferous epochs by the genus Dipterus (2=Ctenodus) ; but that, although Dipterus has internal nostrils and even a pair of vomerine teeth (beside the molars) like the living Dipnoz, it must be placed as the type of a separate family of this suborder, on account of its heterocercy. 6. That the evidence with regard of Phaneropleuron (Huxley) is less conclusive ; and that Tristichopterus (Egerton), with the complete segmen- tation of its vertebral column, must be excluded from this suborder. 7. That the suborder Crossopterygii (Huxley) contains two distinct types of “lobate fin,’ viz. the ‘‘obtusely lobate,’’ with a transverse series of carpal cartilages, and the ‘‘ acutely lobate’’ with an axial skeleton. Only the latter type agrees with the structure of the Dipnoous limb. But Polypterus, Coelacanthus, &c., which are provided with fins of the former type, are genera sufficiently distinguished also by other characters, to be placed into a separate suborder. 380 On some of the Subaxial Arches in Man. [ Mar. 16, II. “On the formation of some of the Subaxial Arches in Man.’ By Grorcre W. Catienver, Assistant Surgeon to, and Lec- turer on Anatomy at St. Bartholomew’s Hospital. Communi- cated by J. Pacer, F.R.S. Received February 17, 1871. (Abstract.) In the term subaxial arches is included all those which grow out in front of the notochord. The first forms the nasal passages, the second forms chiefly the superior maxilla, the third is the mandibular, the fourth the lingual, the fifth the hyoid, the sixth the laryngeal, whilst the seventh, which is distinguished as the exoccipital arch, forms the shoulder-girdle and the thoracic extremity of either side. The consideration of the connexion of the first four with the cranial cartilages is for the present deferred; and this communication relates to those arches which grow into the cervical region, and to that period of their growth which lies between the fifth and twelfth weeks of fcetal life. The fourth subaxial arch, the lingual, grows out below the mandibular, and bears upon its anterior extremity the tissue which developes into the tongue. Its connexion with this anterior portion ceases to be recognized at an early period, and about the eleventh week it consists of five portions, (1) cartilage from the base of the skull, (2) a short piece of membrane, (3) a second very small rod of cartilage, these forming about one-half of its length, (4) a long strip of membrane, and (5) a nodule of cartilage within the lesser or anterior horn of the hyoid bone. The fifth subaxial arch, the hyoid, grows in common with the sixth as a layer of membrane from the basioccipital region. The posterior portion of it forms the middle constrictor muscle; the remainder is cartilaginous, and grows into the greater or posterior horn and the body of the hyoid bone. The sixth subaxial arch, the laryngeal, begins in membrane which forms the inferior constrictor. Rising up and thickening in the front of the neck, it encloses the pharynx; and its inner layer developes a septum, which separates this tube from the larynx. In front, and between this inner layer and that in which the constrictor is formed, a mass of thick granular tissue becomes cartilage, and here the chief cartilages of the larynx are formed. The details of their formation are referred to. The thyroid body is developed in this arch, and it serves as a girdle to surround and keep in place the continuation of the air-tube towards the thorax. Its relation to the branchial arches is also referred to. After mentioning the reason for calling the seventh arch the exoccipital, its growth from the basioccipital and exoccipital cartilage regions is de- scribed, with its ending in two processes which grow out as the clavicle and the scapula. The relations of the clavicle to the sternum and first rib are related, as also its change in direction from a nearly vertical to a hori- 1871.] On the Successive Polarization of Light. 881 zontal position. The curling round of the scapula-rod is described, and the outgrowth from the rod of plates of bone bounded by the acromial, glenoid, and coracoid borders. The relations of the sterno-mastoid, trape- zius, and levator anguli scapule muscles are referred to. The growth of the glenoid cavity outwards from the acromion and coracoid is noticed at about the eleventh week, at which period the cape. has acquired its chief per- manent characters. March 23, 1871. General Sir EDWARD SABINE, K.C.B., President, in the Chair. The following communications were read :— I. “Experiments on the Successive Polarization of Light, with the description of a new Polarizing Apparatus.” By Sir Cuartes Wuearstone, F.R.S. Received Feb. 2, 1871. I. The term successive polarization was applied by Biot to denote the effects produced when a ray of polarized light is transmitted through a plate of rock--crystal cut perpendicularly to the axis, or through limited depths of certain liquids. In these cases the plane of polarization is found to be changed on emergence, and differently for each homogeneous ray ; so that, when white light is employed, on turning the peers round con- tinuously in one direction different colours successively appear, rising or falling in the scale according to the nature of the substance. If, while the analyzer is turned from left to right, the tints ascend (z..e. follow the order R, O, Y, G, B, P, V), the substance is said to ex- hibit right-handed successive polarization, but if the tints descend, the successive polarization is said to be left-handed. These phenomena were satisfactorily explained by Fresnel in the following way. The incident polarized ray, instead of resolving itself into two plane- polarized rays at right angles to each other, as in the ordinary cases of di- polarization, resolves itself in these instances into two circularly polarized rays, one right-handed the other left-handed, which are transmitted with different velocities ; each homogeneous ray, thus resolved into two opposite circularly polarized pencils, on emergence composes a ray polarized in a single plane, the deviation of which from the primitive plane of polariza- tion depends on the difference of phase of the two circularly polarized rays on emergence. The rotation of the planes of polarization is from left to right, or from right to left, according to whether the right-handed or efehanded circular rays are transmitted vith the greater velocity. EL: The term dipolarization, proposed by Dr. Whewell to express the VOL. XIX. 26 382 Sir C. Wheatstone on the [ Mar. 23, bifurcation which a ray of polarized light suffers when it is transmitted through a crystallized plate, is a very appropriate one; but as there are different kinds of such separation, we may designate plane dipolarization the resolution into two plane-polarized rays at right angles to each other, and circular dipolarization the resolution into two circularly polarized rays, one right-handed, the other left-handed. In like manner the term elliptic dipolarization may be employed to represent the phenomena shown by transmitting a polarized ray through a plate of rock-erystal obliquely to the axis. ) The object of the present communication is to make known another means of producing successive polarization, both right-handed and left- handed, which, equally with the well-known modes, may be proved to arise from the interference of two opposite systems of circularly polarized rays. ETB, The polarizing-apparatus which I have employed for the experiments I am about to detail is represented by Pl. IV. A plate of black glass, G, is fixed at an angle of 3° to the horizon. The film to be examined is to be placed on a diaphragm, D, so that the light reflected at the polarizing-angle from the glass plate shall pass through it at right angles, and, after reflection at an angle of 18° from the surface of a polished silver plate S, shall proceed vertically upwards. WN is a Nicol’s prism, or any other analyzer, placed in the path of the second reflection. The diaphragm is furnished with a ring, moveable in its own plane, by which the crystallized plate to be examined may be placed in any azimuth. C is a small moveable stand, by means of which the film to be examined may be placed in any azimuth and at any inclination; for the usual expe- riments this is removed. If a lamina of quartz cut parallel to the axis, and sufficiently thin to show the colours of polarized light, be placed upon the diaphragm so that its principal section (7. e. the section containing the axis) shall be 45° to the /eft of the plane of reflection, on turning the analyzer from left to right, instead of the alternation of two complementary colours at each quadrant, which appear in the ordinary polarizing apparatus, the phe- nomena of successive polarization, exactly similar to those exhibited in the ordinary apparatus by a plate of quartz cut perpendicular to the axis, will be exhibited ; the colours follow in the order R, O, Y, G, B, P, V, or, in other words, ascend as in the case of a right-handed plate of quartz cut perpendicularly to the axis. If the lamina be now either in- verted, or turned in its own plane 90°, so that the principal section shall be 45° to the right of the plane of reflection, the succession of the colours will be reversed, while the analyzer moves in the same direction as before, presenting the same phenomena as a left-handed plate of quartz cut per- pendicularly to the axis. Quartz is a positive doubly refracting erystal ; and in it consequently the ordinary index of refraction is smaller than the W.H- Wesley lith W. West & C° imp. 1871.) | Successive Polarization of Light. 383 extraordinary index. But if we take a lamina of a negative crystal, in which the extraordinary index is the least, as a film of Iceland spar split parallel to one of its natural cleavages, the phenomena are the reverse of those exhibited by quartz: when the principal section is on the left of the plane of reflection the colours descend, and when it is on the right of the same plane the colours ascend, the analyzer being turned from left to right. | It has been determined that the ordinary ray, both in positive and negative crystals, is polarized in the principal section, while the extra- ordinary ray is polarized in the section perpendicular thereto. It is also established that the index of refraction is inversely as the velocity of transmission. It follows from the above experimental results, therefore, that when the resolved ray whose plane of polarization is to the left of the plane of reflection is the quickest the successive polarization is right- handed, and when it is the slowest the successive polarization is left- handed—in the order R, O, Y, G, B, P, V, and in the second case in the reversed order. The rule thus determined is equally applicable to laminz of biaxal crystals. As selenite (sulphate of lime) is an easily procurable crystal, and readily cleavable into thin laminze capable of showing the colours of polarized light, it is most frequently employed in experiments on chromatic polar- ization. The laminz into which this substance most readily splits, contain in their planes the two optic axes; polarized light transmitted through such laminz is resolved in two rectangular directions, which respectively bisect the angles formed by the two optic axes: the line which bisects the smallest angle is called the intermediate section ; and the line perpendicular thereto which bisects the supplementary angle is called the supplementary section. These definitions being premised, if a film of sele- nite is placed on the diaphragm with its intermediate section to the left of the plane of reflection, the successive polarization is direct or right-handed ; if, on the contrary, it is placed to the right of that plane, the successive polarization is left-handed. The ray polarized in the intermediate section is therefore the most retarded; and as that section is considered to be equivalent to a single optic axis, the crystal is positive. In one kind of mica the optic axes are in a plane perpendicular to the laminz. They are inclined 223° on each side the perpendicular within the crystal, but, owing to the refraction, are seen respectively at an angle of 35°°3 therefrom. The principal section is that which contains the two optic axes. If the film is placed on the diaphragm with its principal section inclined 45° to the left of the plane of reflection, the successive polarization is right-handed. The ray, therefore, polarized in the section which contains the optic axes is the one transmitted with the greatest velocity. Films of uniaxal crystals, whether positive or negative, and of biaxal 2G2 384: . Sir C. Wheatstone on the -[ Mar. 23, crystals, all agree therefore in this respect :—that if the plane of polarization of the quickest ray is to the left of the plane of reflection, the successive polarization is right-handed when the analyzer moves from left to right; and if it is to the right of the plane of reflection, other cireumstances remaining the same, the successive polarization is left-handed. It must be taken into consideration that the principal section of the film is inverted in the reflected image ;_ so that if the plane of polarization of the quickest ray in the film is to the left of the plane of reflection, it is to the right of that plane in the reflected image. IV. It may not be uninteresting to state a few obvious consequences of this successive polarization in doubly refracting lamine, right-handed and left-handed according to the position of the plane of polarization of the quickest ray. They are very striking as experimental results, and will serve to impress the facts more vividly on the memory. 1. A film of uniform thickness being placed on the diaphragm with its principal section 45° on either side the plane of reflection, when the analyzer is at 0° or 90° the colour of the film remains unchanged, whether the film be turned in its own plane 90°, or be turned over so that the back shall become the front surface; but if the analyzer be fixed at 45°, 135°, 225°, or 315°, complementary colours will appear when the film is in- verted from back to front, or rotated in its own plane either way 90°. 2. Ifa uniform film be cut across and the divided portions be again placed together, after inverting one of them, a compound film (fig. 4) is formed, which, when placed on the diaphragm, exhibits simultaneously both right-handed and left-handed successive polarization. When the analyzer is at 0° or 90° the colour of the entire film is uniform; as it 1s turned round the tints of one portion ascend, while those of the other descend ; and when the analyzer is at 45° or n90°+ 45°, they exhibit complementary colours. 3. A film increasing in thickness from one edge to the other is well suited to exhibit at one glance the phenomena due to films of various thicknesses. It is well known that such a film placed between a polarizer and an analyzer will show, when the two planes are parallel or perpen= dicular to each other, and the principal section of the film is mtermediate to these two planes, a series of parallel coloured bands, the order of the colours in each band from the thick towards the thm edge being that of their refrangibilities, or R, O, Y, G, B, P, V. The bands seen when the planes are perpendicular are intermediate in position to those.seen when the planes are parallel; on turning round the analyzer these two systems of bands alternately appear at each quadrant, while 1 in oe intermediate positions they entirely disappear. Now let us attend to the appearances of these bands: hen the wedge- form film is placed on the diaphragm of the instrument, fig. 1. . As the ya a lade Successive Polarization of Light. 385. analyzer is moved round, the bands advance toward or recede from the thin edge of the wedge without any changes occurring in the colours or in- tensity of the light, the same tint occupying the same place at every half revolution of the analyzer. If the bands advance toward the thin edge of: the wedge, the successive polarization of each point is left-handed ; and if they recede from it the succession of colours is right-handed ; every cir- cumstance, therefore, that with respect to a uniform film changes right- handed into left-handed successive polarization, in a wedge of the same substance transforms receding into advancing bands, and vice versd. These phenomena are also beautifully shown by concave or convex films of selenite or rock-crystal, which exhibit concentric rings contracting or expanding in accordance with the conditions previously explained. 4. Few experiments in physical optics are so beautiful and striking as the elegant pictures formed by cementing laminz of selenite of different. thicknesses (varying from 5,);5 to +; of an inch) between two plates of glass. Invisible under ordinary circumstances, they exhibit, when exa- mined in the usual polarizing-apparatus, the most brilliant colours, which are complementary to each other in the two rectangular positions of the analyzer. Regarded in the instrument, fig. 1, the appearances are still more beautiful; for, instead of a single transition, each colour in the. picture is successively replaced by every other colour. In preparing such pictures it is necessary to pay attention to the direction of the principal section of each lamina when different pieces of the same thickness are to be combined together to form a surface having the same uniform tint ; otherwise in the intermediate transitions the colours will be irregularly disposed. : 5. A plate of rock-crystal eut perpendicular to the axis loses its suc- cessive polarization, and behaves exactly as an ordinary crystallized film through which rectilinear polarized light is transmitted. 6. A thick plate of unannealed glass undergoes a series of ‘regular transformations, the principal phases of which are shown, fig. 5. VY. - The phenomena of successive or rotatory polarization I have experi- mentally demonstrated admit of a very simple explanation. The polarized light incident on the crystallized plate is resolved into two portions of equal intensity, polarized at right angles to each other, one in the principal section, the other perpendicular thereto. These resolved portions, when they fall on the silver plate, have their planes of polariza- tion each at an azimuth of 45°, one to the right, the other to the left of the plane of reflection. These are again resolved in the plane of reflection and the plane perpendicular thereto, and are, in consequence of the unequal retardation, which in silver at an angle of 72° amounts to a quarter of an undulation, converted into cirenlanly polarized beams, one right-handed,’ the other left-handed. 386 _ Sir C. Wheatstone on the {Mar. 23, The various homogeneous rays being accelerated differently in their transmission through the two sections of the crystallized plate, this dif- ference is preserved after reflection from the silver plate, and the oppositely circularly polarized beams are reflected with the same difference of phase as the two plane-polarized rays are when emerging from the crystallized lamina. The composition of two circular waves, one right-handed, the other left-handed, gives for resultant a plane wave the azimuth of which varies with the difference of phase of the two components. When the plane of polarization does not he equally between the two rectangular sections of the lamine, these still remaining 45° from the plane of reflection of the silver plate, the beam is resolved into two unequal portions, the amplitudes of which are as sin a to cos a. Each therefore gives rise to a circular undulation of different amplitude. The resultant of two opposite circular undulations of different amplitudes is an ellipse of constant form, the axes of which vary in position according to the difference of phase. The same phenomena of successive polarization are therefore exhibited, in whatever azimuth the lamina is turned in its own plane; but the tints become fainter and fainter until ultimately, when the principal or perpendicular section is parallel to the plane of reflection of the polarizing plate, all colour disappears. VI. By means of the phenomena of successive polarization it is easy to determine which is the thicker of two films of the same crystalline substance. Place one of the films on the diaphragm (a) of the instrument (fig. 1a) in the position to show, say, right-handed polarization, then cross it with the other film; if the former be the thicker, the successive polarization will be still right-handed ; if both be equal there will be no polarization ; and if the crossed film be the thicker, the successive polarization will be left- handed. In this manner a series of films may be readily arranged in their proper order in the scale of tints. VII. In the experiments I have previously described the planes of re- flection of the polarizing mirror and of the silver plate were coincident ; some of the results obtained when the azimuth of the plane of reflection of the silver plate is changed are interesting. I will confine my attention here to what takes place when the plane of reflection of the silver plate is 45° from that of the polarizing reflector. When the principal sections of the film are parallel and perpendicular to the plane of reflection of the polarizing mirror, as the whole of the polarized light passes through one of the sections, no interference can take place, and no colour will be seen, whatever be the position of the analyzer. When the principal sections of the film are parallel and perpendicular i i in 1871.} Successive Polarization of Light. 387 to the plane of reflection of the silver plate, they are 45° from the plane of reflection of the polarizing mirror. The polarized ray is then resolved into two components polarized at right angles to each other; one component is polarized in the plane of reflec- tion of the silver plate, the other perpendicular thereto; and one is re- tarded upon the other by a quarter of an undulation. When the analyzer is at 0° or 90° no colours are seen, because there is no interference; but when it is placed at 45° or 135°, interference takes place, and the same colour is seen as if light circularly polarized had been passed through the film. The bisected and inverted film (fig. 4) shows stmultaneously the two complementary colours. But when the film is placed with one of its principal sections 223° from the plane of refléction of the polarizing mirror, on turning round the ana- lyzer the appearances of successive polarization are reproduced exactly as when the planes of reflection of the silver plate and of the polarizing mirror coincide. In this case the components of the light oppositely polarized in the two sections are unequal, being as cos 223° to sin 223°; these com- ponents respectively fall 223° from the plane of reflection of the silver plate and from the perpendicular plane, and are each resolved in the same proportion in these two planes. The weak component of the first, and the strong component of the second, are resolved into the normal plane, while the strong component of the first and the weak component of the second are resolved into the perpendicular plane. VIII. As bearing intimately on the subject of this paper, I will here quote a passage from a memoir presented by Fresnel to the French Academy of Sciences in 1817, and published, in abstract, in the ‘ Annales de Chimie,’ t. xxvil. 1825 :— “Tf a thin crystallized plate be placed between two parallelopipeds of glass crossed at right angles, in each of which the light previously po- larized undergoes two total reflections at the incidence of 543°, first before its entrance into the plate (which we suppose perpendicular to the rays), and subsequently after its emergence, and if, besides, the plate be turned so that its axis makes an angle of 45° with the two planes of double reflection, this system will present the optical properties of plates of rock- crystal perpendicular to the axis, and of liquids which colour polarized light. When the principal section of the rhomboid with which the emer- gent lght is analyzed is turned round, the two images will gradually change colour, instead of experiencing only simple variations in the vivid- ness of their tints, as occurs in the ordinary case of thin crystallized plates ; besides, the nature of these colours depends only on the respective inclination of the primitive plane of polarization and the principal section of the rhomboid—that is to say, of the two extreme planes of polarization ; thus, when this angle remains constant, the system of the crystallized 388, On the Successive Polarization of Light. [Mar. 23, plate. and the two parallelopipeds may be turned round the transmitted pencil without changing the colour of the images. It is this analogy be- tween the optical properties of this little apparatus and those of plates of rock-crystal perpendicular to the axis which enabled M. Fresnel to foresee the peculiar characters - double refraction that rock- er exerts on rays parallel to the axis.’ It does not appear that Fresnel, in any of his published 1 memoirs, has given any further modifications of this experiment, the importance of which has been almost entirely overlooked in elementary treatises on light. He does not seem to have remarked that similar phenomena of successive polarization are exhibited when the light incident on the crystallized plate is plane-polarized, nor that the order of the succession of the colours depends on the position of the principal section with respect to the plane of polarization. These circumstances are indeed necessarily included in the beautiful theory established by this eminent philosopher; but I am not aware that they have hitherto been specifically deduced or experi- mentally shown. IX. The apparatus (fig. 1) affords also the means of obtaining large surfaces of uncoloured or coloured light in eVery state of nolan —rectilinear, elliptical, or circular. It is for this purpose much more convenient than a Fresnel’s rhomb, with which but a very small field.of view can be obtained. It must, how- ever, be borne in mind that the circular and elliptical undulations are inverted in the two methods: in the former case they undergo only a single, in the latter case a double reflection. For the experiments which follow, the crystallized plate must be placed on the diaphragm E between the silver plate and the analyzer, instead of, as in the preceding experiments, between the polarizer and the silver plate. By means of a moving ring within the graduated circle D the silver plate is caused to turn round the reflected ray, so that, while the plane of pola- rization of the ray remains always in the plane of reflection of the glass plate, it may assume every azimuthal position with respect to the plane of reflection of the silver plate. The film to be examined and the analyzer move consentaneously with the silver plate, while the polarizing mirror remains fixed. In the normal position of the instrument the ray polarized by the mirror is reflected unaltered by the silver plate; but when the ring is “turned to 45°, 135°, 225°, or 315°, the plane of polarization of the ray falls 45° on one side of the plane of reflection of the silver plate, and the ray is resolved into two others, polarized respectively in the plane of reflec- tion and the perpendicular plane, one of which is retarded on the other by a quarter of an undulation, and consequently gives rise to a circular ray, which is right-handed or left-handed according to whether the ring is turned 1871.] Ona Decennial Variation of Temperature at the Cape. 389. 45° and 225° or 135° and 315°. When the ring is turned so as to place: the plane of polarization in any intermediate position between those pro- ducing rectilinear and circular light, elliptical light is obtained, on account of the unequal resolution of the ray into its two rectangular components. Turning the ring of the graduated diaphragm from left to right when the crystallized film is between the silver plate and the analyzer, occasions the same succession of colours for the same angular rotation as rotating the analyzer from right to left when the instrument is in its normal posi- tion and the film is between the polarizer and the silver plate. X. - Toarrange the apparatus for the ordinary experiments of plane-polarized: light without the intervention of the silver plate, all that is necessary is to: remove the silver plate from the frame F, and to substitute for it a plate of black glass, which must be fixed at the proper polarizing-angle. To convert it into a Norrenberg’s polarizer, a silvered mirror must be laid: horizontal at H, and the instrument straightened, as shown at fig. 3, so; that a line perpendicular to the mirror shall correspond with the line of sight. The silver plate must be removed from the frame I’, and a plate of transparent glass substituted for it, which must be so inclined that the light falling upon it shall be reflected at the polarizing-angle perpendicu-: larly toward the horizontal mirror. The eye will receive the polarized: ray reflected from the mirror; and the polarized ray will have passed,’ before it reaches the eye, twice through a crystallized plate placed between the mirror and the polarizer. The result is the same asif, in the ordinary apparatus, the polarized ray had passed through a plate of double the thickness. Fig. 2 shows the addition to the apparatus when the coloured rings of crystals are to be examined by light circularly or elliptically polarized : ais the optical tube containing the lenses (which require no particular explanation), and 6 the condenser, over which the plate is to be placed. . II. “On an approximately Decennial Variation of the Temperature at the Observatory at the Cape of Good Hope between the years 1841 and 1870, viewed in connexion with the Variation of the Solar Spots.” By HE. J. Stone, F.R.S., Astronomer Royal at the Cape of Good Hope. In a Letter to the President. Re- ceived February 21, 1871. : Royal Observatory, Cape of Good Hope, Jan. 17,1871. _ Dear Si1r,—I enclose a curve of the variation of the annual mean tem- perature at the Cape deduced from observations extending from 1841 to 1870 inclusive. I have carefully examined the zero-points of all the ther: 390 Mr. E. J. Stone on a Decennial [Mar. 238, mometers which have been employed in this series of observations. I have then deduced the rate of change of these thermometers, from a com- parison of the index-errors thus found and those given originally or ob- tained in 1852 by Sir Thomas Maclear, when he compared the principal thermometers at the Observatory with the readings of a standard “ Reg- nault’’ which had been sent out to the Observatory for that purpose by you. These indications of change have been carefully checked by all the comparisons made, at different times and for different purposes, of these thermometers inter se and with others which still remain at the Observa- tory. From the agreement of the different results thus checked, I have no doubt upon my own mind of the systematic character and sensible amount of the increase of readings of thermometers with age thus indi- cated. In some cases the change appears to amount to as much as 0°:05 F. per annum. From these results I have deduced the index-errors of the different thermometers for the different periods, and applied these corrections throughout. I have also corrected the mean results of the five observations made daily since 1847 in order to deduce the true daily mean. The results thus reduced on a general system, and extending over thirty years, appeared likely to afford information respecting any connexion which might exist between the mean temperature and the frequency of solar ‘spots. I have therefore constructed the curves of variation of mean annual temperature, and the inverse curve of solar-spot frequency for comparison. The latter curve has been founded upon Wolf’s observations. The observations of temperature from 1841 to 1851 inclusive were made in the original Meteorological Observatory, which was burnt down in 1852, March 11. The observations from 1852, April 24, to 1858, August 31, were made in a wooden shed erected for the purpose on the site of the old Observatory. The observations from 1858, August 3lst, to the present time have been made in the crib before the south-west window of the Transit-Circle Room. — | These changes are so far unfortunate that there is clearly a change of mean temperature arising from the different circumstances of exposure. I have therefore referred each set of observations to the mean temperature deduced from all the observations made under the same circumstances of exposure. The deviations of the mean temperature for each year from the mean of the whole period of similar exposure are then laid down as ordi- nates on the scale of one division of the ruled paper to 0°05 F. To smooth down the irregularities, I have joined the points thus laid down, and bisected the lines thus joming these points whenever the corresponding mean temperatures were deduced from a full year’s observations. In other cases the temperatures corresponding to the deficient months have been supplied from the adjoining years, and the resulting mean temperature allowed less weight. The inverse curve of the frequency of solar spots has been formed by simply subtracting 100 from Wolf’s numbers, and 1871.| Variation of Temperature at the Cape. 391 laying down points to the scale of a number 4 to 0°05 F., or one division of the ruled paper. The broken curve represents the variations in the mean annual temperature at the Cape; the continuous line is the inverse curve of solar spots’ frequency. . The agreement between the curves appears to me so close that I cannot but believe that the same cause which leads to an excess of mean annual temperature leads equally to a dissipation of solar spots. There is on the whole a curious appearance of lagging of the inverse curve of solar spots over that of temperature. At the maximum about 1856, however, this does not appear to be the case; but when the uncertainties of the data, 392 MM. Wolf and Fritz on Sun-spots. = [Mar. 23, both of the solar spots near the minimum, and of the mean temperature also, are taken into account, such discrepancies might. perhaps fairly be expected, even if there be a physical connexion between the two pheno- mena as results of some common cause. If there be a sensible inequality in the mean temperature with a period of about ten years, then the mean temperature resulting from the observations in the temporary Observatory, which were made near a maximum, will be too high. The corresponding ordinates, therefore, will be depressed too much relatively to those corre- sponding to observations made in the other two observatories. In the curve 2, I have imperfectly corrected the mean of the results for the tem- porary observatory on the supposition of such an inequality existing. The only result of such a correction is to modify the curve at the points of junction of the observations made in different positions. The general form is unaltered. It should be mentioned that the point about which the curves appear to differ most is near or at the change of exposure from the original observatory to the tempcrary shed, about 1852. I may mention that I had not the slightest expectation, on first laying down the curves, of any sensible agreement resulting, but that I now con- sider the agreement too close to be a matter of chance. I should, however, rather lean to the opinion that the connexion between the variation of -mean temperature and the appearance of solar spots is indirect rather than direct, that each results from some general change of solar-energy. I have forwarded these curves to you, knowing the great interest you have ever taken in such inquiries, and on account of your being the chief promoter of the establishment of a Meteorological Observatory here. The problems of meteorology appear to be presented here in a simpler form than in England ; and probably systematic photographic self-registering observations extended over a few years might lead to important results. I have the honour to be, Sir, Yours obediently, E. J. Stone. Sir Edward Sabine, K.C.B., P.R.S., §e. ILI. Résumé of two payers on Sun-spots:—~ On the Form of the ~ Sun-spot Curve,” by Prof. Woxr; and “On the Connexion * . -of Sun-spots with Planetary Gentoratan™ by M. Fritz. By B. Lozewy. Communicated by Warren De La Roz, F.RS., and B, Stewart, F.R.S. ; Of these two series of investigations, one is by Professor Wolf, the other by M. Fritz, communicated to Wolf. In the first, Prof. Wolf has proposed to himself to find the mean cha- tacter of the curve of sun-spots, z.e. its real form from one minimum to another. He investigates the form only for 24 years before, and 23 years 1871.] Mr. F. Galton’s Experiments in Pangenesis. 393 after each minimum, and concludes by a simple proportion of the re mainder. He finds that the curve ascends more rapidly than it descends— the ascent taking in the mean 3°7 years, the descent lasting 7-4 years. We have established these data far more reliably in our last paper; and our curve gives 3-52 years for the ascent, 7°54 years for the descent (average of the three periods). Professor Wolf also thinks that although a single period may differ essentially in its character and form from the mean, ‘still; on the whole, if the descent is retarded, the ascent in the same period is also retarded ; if the former is accelerated, the latter is also accelerated. This is not quite borne out by our curve. He also overlooks the se- condary maximum, which may lead to great conclusions if more investi+ gated together with other matters. M. Fritz comes to the following conclusions. :— 1. The connexion between sun-spots and auroral and magnetic distort! ances indicates an external cause, to be sought in planetary configurations. . The relative influence of the planets must be exerted in the following 6 :—Jupiter (greatest), Venus, Mercury, Earth, Saturn. 3. This influence cannot entirely depend on the time of rotation ; but changes in the magnetic axes of these planets may have the most deter- mining effect. , 4. Investigating the comparative influences of them singly and together (as far as possible), at the times of conjunction and quadrature, he finds the greatest coincidence of maxima of sun-spots with the time when Jupiter and Saturn are in quadrature ; and the greatest coincidence of minima when these planets are in conjunction. 5. There is also (a minor) coincidence of maxima when Jupiter and Venus are in quadrature. ; There is also an extension of the paper for finding the connexions with auroras, and a statement that every 27°7 days there seems to be a monthly maximum, which may probably be explained (according to Fritz) by the tendency of a particular solar meridian to spot-formations, depending upon the presence of an intra- Mercurial planet. March 30, 1871. : General Sir EDWARD SABINH, K.C.B., President, in the Jie The following communications were read :— I. “ Experiments in Pangenesis, by Breeding from Rabbits of a pure variety, into whose circulation blood taken from other varieties had previously been largely transfused.” By Francis GaLrony F.R.S. Received March 23, 1871. : Darwin’s provisional theory of Pangenesis claims our belief on the ground that it is the only theory which explains, by a single law, the numerous $94 Mr. F. Galton’s Experiments in Pangenesis. [Mar. 30, phenomena allied to simple reproduction, such as reversion, growth, and repair of injuries. On the other hand, its postulates are hypothetical and large, so that few naturalists seem willing to grant them. To myself, as a student of Heredity, it seemed of pressing importance that these postu- lates should be tested. If their truth could be established, the influence of Pangenesis on the study of heredity would be immense; if otherwise the negative conclusion would still be a positive gain. It is necessary that I should briefly recapitulate the cardinal points of Mr. Darwin’s theory. They are (1) that each of the myriad cells in every living body is, to a great extent, an independent organism; (2) that before it is developed, and in all stages of its development, it throws ‘“‘ gemmules” into the circulation, which live there and breed, each truly to its kind, by the process of self-division, and that, consequently, they swarm in the blood, in large numbers of each variety, and circulate freely with it ; (3) that the sexual elements consist of organized groups of these gem- mules; (4) that the development of certain of the gemmules in the offspring depends on their consecutive union, through their natural affinities, each at- taching itself to its predecessor in a regular order of growth ; (5) that gem- mules of innumerable varieties may be transmitted for an enormous number of generations without being developed into cells, but always ready to be- come so, as shown by the almost insuperable tendency to feral reversion, in domesticated animals. It follows from this, and from the general tenor of Mr. Darwin’s rea- soning and illustrations, that two animals, to outward appearance of the same pure variety, one of which has mongrel ancestry and the other has not, differ solely in the constitution of their blood, so far as concerns those points on which outward appearance depends. The one has none but gemmules of the pure variety circulating in his veins, and will breed true to his kind ; the other, although only the pure variety of skin-gemmules happens to have been developed in his own skin, has abundance of mongrel gemmules in his blood, and will be apt to breed mongrels. It also follows from this that the main stream of heredity must flow in a far smaller volume from the developed parental cells, of which there is only one of each variety, than from the free gemmules circulating with the blood, of which there is a large number of each variety. If a parental developed cell bred faster than a free gemmule, an influx of new immigrants would gradually supplant the indi- genous gemmules; under which supposition, a rabbit which, at the age of six months, produced young which reverted to ancestral peculiarities, would, when five years old, breed truly to his individual peculiarities ; but of this there is no evidence whatever. | Under Mr. Darwin’s theory, the gemmules in each individual must therefore be looked upon as entozoa of his blood, and, so far as the pro- blems of heredity are concerned, the body need be looked upon as little more than a case which encloses them, built up through the development of some of their number. Its influence upon them can be only such as 1871.] Mr. F. Galton’s Experiments in Pangenesis. 395 would account for the very minute effects of use or disuse of parts, and of acquired mental habits being transmitted hereditarily. It occurred to me, when considering these theories, that the truth of Pangenesis admitted of a direct and certain test. I knew that the opera- tion of transfusion of blood had been frequently practised with success on men as well as animals, and that it was not a cruel operation—that not only had it been used in midwifery practice, but that large quantities of saline water had been injected into the veins of patients suffering under cholera. I therefore determined to inject alien blood into the circulation of pure varieties of animals (of course, under the influence of anesthetics), and to breed from them, and to note whether their offspring did or did not show signs of mongrelism. If Pangenesis were true, according to the inter- pretation which I have put upon it, the results would be startling in their novelty, and of no small practical use; for it would become possible to modify varieties of animals, by introducing slight dashes of new blood, in ways important to breeders. Thus, supposing a small infusion of bull-dog blood was wanted in a breed of greyhounds, this, or any more complicated admixture, might be effected (possibly by operating through the umbilical cord of a newly born animal) in a single generation. I have now made experiments of transfusion and cross circulation on a large scale in rabbits, and have arrived at definite results, negativing, in my opinion, beyond all doubt, the truth of the doctrine of Pangenesis. The course of my experiments was as follows :—Towards the end of 1869, I wrote to Dr. Sclater, the Secretary of the Zoological Society, ex- plaining what I proposed to do, and asking if I might be allowed to keep my rabbits in some unused part of the Gardens, because I had no ac- commodation for them in my own house, and I was also anxious to obtain the skilled advice of Mr. Bartlett, the Superintendent of the Gardens, as to their breed and the value of my results. I further asked to be permitted to avail myself of the services of their then Prosector, Dr. Murie, to make the operations, whose skill and long experience in minute dissection is well known. I have warmly to thank Dr. Sclater for the large assistance he has rendered to me, in granting all I asked, to the full, and more than to the full ; and I have especially to express my obligations to the laborious and kind aid given to me by Dr. Murie, at real inconvenience to himself, for he had little leisure to spare. The whole of the operations of transfusion into the jugular vein were performed by him, with the help of Mr. Oscar Fraser, then Assist- ant Prosector, and now appointed Osteologist to the Museum at Calcutta, I doing no more than preparing the blood derived from the supply-animal, performing the actual injection, and taking notes. The final series of opera- tions, consisting of cross-circulation between the carotid arteries of two varieties of rabbits, took place after Dr. Murie had ceased to be Prosector. They were performed by Mr. Oscar Fraser in a most skilful manner, though he and I were still further indebted, on more than one occasion, to Dr. Murie’s advice and assistance. My part in this series was limited to in- 396 Mr. F. Galton’s Experiments in Pangenesis. [Mar. 80, ‘serting and tying the canulz, to making the cross-connexions, to recording the quality of the pulse through the exposed arteries, and making the other Necessary notes. The breed of rabbits which I endeavoured to mongrelize was the “‘ Silver- grey.” I did so by infusing blood into their circulation, which I had pre- viously drawn from other sorts of rabbits, such as I could, from time to time, most readily procure. I need hardly describe Silver-grey rabbits with minuteness. They are peculiar in appearance, owing to the intimate mixture of black and grey hairs with which they are covered. They are never blotched, except in the one peculiar way I shall shortly describe ; and they have never lop ears. ‘They are born quite black, and their hair begins to turn grey when a few weeks old. The variations to which the breed is liable, and which might at first be thought due to mongrelism, are white tips to the nose and feet, and also a thin white streak down the forehead. But these variations lead to no uncertainty, especially as the white streak lessens or disappears, and the white tips become less marked, as the animal grows up. Another variation is much more peculiar: it is the tendency of some breeds to throw ‘‘ Himalayas,” or white rabbits with black tips. From first to last I have not been troubled with white Himalayas; but in one of the two breeds which I have used, and which I keep carefully sepa- rated from each other, there is a tendency to throw “ sandy”? Himalayas. One of these was born a few days after I received the animals, before any operation had been made upon them,.and put me on my guard. A similar one has been born since an operation. Bearing these few well-marked ex- ceptions in mind, the Silver-grey rabbit is excellently adapted for breeding- experiments. If it is crossed with other rabbits, the offspring betray mon- grelism in the highest degree, because any blotch of white or of colour, which is not ‘‘ Himalayan,” is almost certainly due to mongrelism; and so also is any decided change in the shape of the ears. I shall speak in this memoir of litters connected with twenty silver- grey rabbits, of which twelve are does and eight are bucks; and eighteen of them have been submitted to one or two of three sorts of operations. These consisted of :— (1) Moderate transfusion of partially defibrinized blood. The silver- grey was bled as much as he could easily bear ; that was to about an ounce, a quantity which bears the same proportion to theweight of his body (say 76 oz.) that 2 lbs. bears to the weight of the body of a man (say 154 lbs.) ; and the same amount of partially defibrinized blood, taken from a killed animal of another variety, was thrown in in its place. The blood was ob- tained from a yellow, common grey, or black and white rabbit, killed by dividing the throat, and received in a warmed basin, where it was stirred with a split stick to remove part of the fibrine. Then it was filtered through linen into a measuring-glass, and thence drawn up with a syringe, graduated into drachms; and the quantity injected was noted. -. (2) The second set of operations consisted in a large transfusion of wholly 1871.] Mr. F. Galton’s Ewperiments in Pangenesis. 397 defibrinized blood, which I procured by whipping it up thoroughly with a whisk of rice-straw ; and, in order to procure sufficient blood, I had on one occasion to kill three rabbits. I alternately bled the silver-grey and in- jected, until in some cases a total of more than 3 ounces had been taken out and the same quantity, wholly defibrinized, had been thrownin. This proportion corresponds to more than 6 lbs. of blood in the case of a man. (3) The third operation consisted in establishing a system of cross-cir- culation between the carotid artery of a silver-grey and that of a common rabbit. It was effected on the same principle as that described by Addison and Morgan (Essay on Operation of Poisonous Agents upon the Living Body. Longman & Co., 1829), but with more delicate apparatus and for a much longer period. The rabbits were placed breast to breast, in each other’s arms, so that their throats could be brought close together. A carotid of each was then exposed; the circulation in each vessel was temporarily stopped, above and below, by spring holders; the vessels were divided, and short canule, whose bores were larger than the bore of the artery in its normal state, were pressed into the mechanically distended mouths of the arteries; the canule were connected cross-wise ; the four spring holders were released, and the carotid of either animal poured its blood direct into the other. The operation was complicated, owing to the - number of instruments employed; but I suspended them from strings run- ning over notched bars, with buttons as counterpoises, and so avoided en- tanglement. These operations were exceedingly successful; the pulse bounded through the canule with full force ; and though, in most cases, it began to fall off after ten minutes or so, and I was obliged to replace the holders, disconnect the canulee, extract the clot from inside them with a miniature corkscrew, reconnect the canulee, and reestablish the cross-flow two, three, or more times in the course of a single operation, yet on two occasions the flow was uninterrupted from beginning to end. The buck rabbit, which I indicate by the letter O, was 373 minutes in the most free cross-circulation imaginable with his ‘‘ blood-mate,” a large yellow rabbit. There is no mistaking the quality of the circulation m a bared artery ; for, when the flow is perfectly free, the pulse throbs and bounds between the finger and thumb with a rush, of which the pulse at the human wrist, felt in the ordinary way, gives an imperfect conception. These, then, are the three sorts of operations which I have performed on the rabbits; it is convenient that I should distinguish them by letters. I will therefore call the operation of simply bleeding once, and then injecting, by the letter u; that of repeated bleedings and repeated injec- tions by the letter w; and that of cross-circulation by the letter z. In none of these operations did I use any chemical means to determine the degree to which the blood was changed; for I did not venture to com- promise my chances of success by so severe a measure; but I adopted the following method of calculation instead :— VOL, XIX. 2u 398 Mr. F. Galton’s Experiments in Pangenesis. [Mar. 80, I calculate the change of blood effected by transfusion, or by cross-cir- culation, upon moderate suppositions as to the three following matters :— (1) The quantity of blood in a rabbit of known weight. (2) The time which elapses before each unit of incoming blood is well mixed up with that already in the animal’s body. (3) The time occupied by the flow, through either carotid, of a volume of blood equal to the whole contents of the circulation. As regards 1, the quantity of blood im an animal’s body does not ad- mit, by any known method, of being accurately determined. Iam content to take the modern rough estimate, that it amounts to one-tenth of its total weight. If any should consider this too little, and prefer the largest estimate, viz. that in Valentin’s ‘ Repertorium,’ vol. 11. (1838), p. 281, where it is given for a rabbit as one part in every 6-2 of the entire weight, he will find the part of my argument which is based on transfusion to be weakened, but not overthrown, while that which relies on cross-circulation is not sensibly affected. As regards 2, the actual conditions are exceedingly complex; but we may evade their difficulty by adopting a limiting value. It is clear that when only a brief interval elapses before each unit of newly infused blood is mixed with that already in circulation, the quality of the blood which, at the moment. of infusion into one of the cut ends of the artery or vein, is flowing out of the other, will be more alienized than if the interval were longer. It follows that the blood of the two animals will intermix more slowly when the interval is brief than when it is long. Now I propose to adopt an extreme supposition, and to consider them to mix instantaneously. The results I shall thereby obtain will necessarily be less favourable to change than the reality, and will protect me from the charge of exaggera- ting the completeness of intermixture. As regards 3, I estimate the flow of blood through either carotid to be such that the volume which passes through it in ten minutes equals the whole volume of blood in the body. Thisisa liberal estimate ; but I could afford to make it twice or even thrice as liberal, without prejudice to my conclusions. Upon the foregoing data the following Table has been constructed. The formule are:—Let the blood in the Silver-grey be called a, and let its volume be V, and let the quantity u of alien blood be thrown in at each injection, then the quantity of blood a ea in the Silver-grey’s circu- lation, after n injections, u\n If the successive injections be numerous and small, so as to be equivalent to a continuous flow, then, after w of alien blood has passed in, the for- Ww mula becomes V.e V. 1871.] Mr. F. Galton’s Experiments in Pangenesis. 399 A comparison of the numerical results from these two formule shows that no sensible difference is made if (within practicable limits) few and large, or many and small, injections are made, the total quantity injected being the same. Tn cross-circulation the general formula is this :—If V! be the volume of blood in the other rabbit, after w of alien blood has passed through either canula, the quantity of blood a remaining in the Silver-grey exceeds * HY oe 2w TW fvsvie (vty) |. This becomes 31 L+e V } when V=V'; also, when V’ is infinite, it gives the formula already mentioned for injec- tion by a continuous flow of purely alien blood. Tasue I. (Contents of circulation of Silver-grey Rabbit= 100.) Maximum percentage of original blood remaining Pood nee 3 aiter : Z ; nutes, during which the continuous Quantity of Cross-circulation. Continu- blood { Successive injections | ous flow ‘ g infused. fof purely ation blood, |of purely} Rabbits ee pee each= Sad ae roe than the has lasted. Ca Soe: * |Silver-grey. 25 80 23. 50 68 5 75 60 Tk 100 55 10 125 52 123 150 51 15 175 50 174 300 48 30 400 48 40 infinite infinite 10) 48 infinite. I now give a list (Table II.) of the rabbits to which, or to whose blood. mates, I shall have to refer. Every necessary particular will be found in the Table :—the weight of the rabbits; the estimated weight of blood in their veins; the operations performed on them, whether uw, w, or x; the particulars of those several operations ; the estimated percentage of alien blood that was substituted for their natural blood ; and lastly, the colour, size, and breed of their blood-mates. * T am indebted to Mr. George Darwin for this formula. Or ree 400 Mr. F. Galton’s Experiments in Pangenesis. [Mar, 30, TABLE II. Hsti- |Nature! Drachms in- mated | of | fused, and pe- Bolee ws) SG aiaan &e. of : Weight Silvery eroy f ; ; of alienized Does. rabbit, |Weight off opera- riod of cross- | 4) 05 a blood-mate. blood. | tion*.! circulation. | Ibs. oz. |drachms. A RG 79 a 9 11 a grey and white. : U 10 12 Yellow, large. 10 min. - B 513 8 x fect, 15 or 20 50, or Common prey. more y very good. ; C 238 78 u 9:5 12 Albino, large. D bo 75 u 5 Himalaya. u Common grey. S = ve x { u = good, \ 50, about|Common grey. F 4 13 61 x 10 mes and white, arge. ‘i 25:5, in 6 in- \ 35 Grey and black, G 411 60 jections. speckled. x Jl neces } 75 Common gre : total. Brey: 15 min. per- H ai ; fect, 15 very 50 Common grey. good. 16 min. per- It x fect, not much| | nearly 50 were more. Yellow, brown JT xz {35 min. perfect. mouth (? Hima- laya). too unsuccess-| a Angora, fawn s v ful to be worth | ? any. { nd Sete | counting. J | dt INones| Ger cere None. | |." 7 eee | Bucks. 9 14 | f{ Yellow, brown | K ee 62 mouth. w Lees nee 32 Yellow and white. | De total. | L 4 13 61 U 11 Common grey. u 14 Black and white. M 4 0 51 24:5, Laitieel| 45 3 black and white a tions, total. in succession. Angora, grey and N AG 58 ry 7 a { white, red eyes. 16:5, in4injec- O (son of i tions, total. | a lors C (w) by x |374 min. perfect. 50 Yellow. an)) 25 to 30 min. ~ t | per foot. \ 0) Common grey. ee 15 min. per- Qt Li bai 2 eds fects 15 very 50 Yellow and white. OB im min. n. pretty Common grey { good. } a { and white. * Note (to 4th column).—w means simple transfusion, by one copious bleeding, and then injecting ; w means compound transfusion by successive bleedings and sucesssive injections; #2 means cross-circulation. + These rabbits belong to a breed liable to throw “Sandy” Himalayas. 1871.] Mr. F. Galton’s Haperiments in Pangenesis 40} TABLE III. Litters subsequent to first transfusion. Both parents Silver-greys. Ave- -Yage proportion of alienized blood in either parent=}; therefore in young 4 also. Out of By Number and character of litters. A K 4 true Silver-greys. A M 5 ditto, but 1 had a white foot to above knee. B K 5 true Silver-greys. C K 6 ditto. D K 4 ditto. E L 6 ditto. 30 all true Silver-greys, except possibly one | instance. | Litters subsequent to second transfusion of buck. Both parents Silver- greys. Average proportion of alienized blood in young about 3. Out of | By Number and character of litters. ae M | 6 true Silver-sreys. Litters subsequent to cross-circulation of buck only, the does being 0 or w. Both parents Silver-greys. Average proportion of blood in young between 7 and i. Out of | By Number and character of litters. | S O 5 true Silver-greys. C O 5 ditto. E O 3 ditto. | 13 alli Silver-greys. Litters subsequent to cross-circulation of both parents (Silver-greys). Average proportion of alienized blood in young fully 3. | Out of | By | Number and character of litters. | B O 3 true Silver-greys. | H O 7 ditto. | H O 7 ditto. I* p* 6 ditto. J* Q* 6 ditto, all but one, a sandy Himalaya. J* p* 8 true Silver-greys. 37 36 Silver-greys, 1 Himalaya. * These rabbits belong to a breed liable to throw ‘“‘ Sandy ” Himalayas. 402 Mr. F. Galton’s Experiments in Pangenesis. [Mar. 30, Litters subsequent to cross-circulation of beth parents (common rabbits). Average proportion of alienized blood in young a little less than 3. Out of By blood-mate| blood-mate Number and character of litters. to to AD) R 8 none Silver-grey, all like father or mother. E Q* 5 ditto. : G O 9 ditto. I* Q* 8 ditto. J* Q* 8 ditto. 38 none Silver-greys. In another list (Table III.) I give particulars of all the litters I have obtained from these rabbits, classified according to the operations which the parents had previously undergone. I will now summarize the results. In the first instance I obtained five does (A, B, C, D, and E) and three bucks (K, L, and M) which had un- dergone the operation which I call u, and which had in consequence about 4 of their blood alienized. I bred from these +, partly to see if I had produced any effect by the little I had done, and chiefly to obtain a stock of young rabbits which would be born with 3% of alien gemmules in their veins, and which, when operated upon themselves, would produce descendants having nearly 7 alienized blood (the exact proportion is 1—(1—4%)*?=4#). I obtained thirty young ones in six litters; and they were all true silver-greys, except, possibly, in one instance (out of the doe A (uw) by the buck M (z)), where one, of a litter of five, had a white fore leg, the white extending to above the knee-joimt. This white leg gave me great hopes that Pangenesis would turn out to be true, though it might easily be accounted for by other causes; for my stock were sickly (both those on which I had not operated and those on which I had suffering severely from a skin disease), and it was natural under those circumstances of ill health that more white than usual should appear in the young. Having, then, had experience in transfusion, and feeling myself capable of managing a more complicated operation without confusion, I began the series which I call w. I left my old lot of does untouched, but obtained one new doe (G(w)), which had undergone the last operation, and three bucks (K (u, w), M (u,w), N (uw, w)) which had undergone both operations, uandw. On endeavouring to breed from them, the result was unexpected, they appeared to have become sterile. The bucks were as eager as pos- sible for the does ; but the latter proving indifferent, I was unable to testify to their union having taken place; so I left them in pairs, in the same hutch, for periods of three days at a time. Attempts were made in this * These rabbits belong to a breed liable to throw “ Sandy” Himalayas. + I always allowed the bucks to run for awhile with waste does before commencing the breeding-experiments, that all old reproductive material might be got rid of. 1871.] Mr. F. Galton’s Experiments in Pangenesis. 403 way, to breed from them in seven instances; and five of them were utter failures. One case was quite successful ; and that, fortunately, was of the same pair (A (w) and M (wu, w)) which, under the uw operation, had bred the white-footed young one. ‘This time, the offspring (six in number) were pure silver-greys. The last case was unfortunate. The doe (E(u)) had been once sterile to its partner (N (u, w)), and she had been put again in the same hutch with him for a short period, but was thought not to have taken him. She was shortly afterwards submitted to the operation zx. From this she had nearly recovered when she brought forth an aborted litter and died. I was absent from town at the time; but Mr. Fraser, who examined them, wrote to say he fully believed that some were pied; if so, it must have been under the influence of the cross-circulation. But I have little faith in the appearance of the skin of naked, immature rabbits ; for I have noticed that difference of transparency, and the colour of underlying tissues, give fallacious indications. My results thus far came to this, viz. that by injecting defibrinized blood I had produced no other effect than temporary sterility. If the sterility were due to this cause alone, my results admitted of being interpreted in a sense favourable to Pangenesis, because I had deprived the rabbits of a large part of that very component of the blood on which the restoration of tissues depends, and therefore of that part in which, according to Pan- genesis, the reproductive elements might be expected to reside. I had injected alien corpuscles but not alien gemmules. The possible success of the white foot, in my first litters, was not contradicted by the absence of any thing of the sort in my second set, because the additional blood I had thrown in was completely defibrinized. It was essential to the solution of the problem, that blood in its natural state should be injected; and I thought the most convenient way of doing so was by establishing cross- circulation between the carotids. If the results were affirmative to the truth of Pangenesis, then my first experiments would not be thrown away ; for (supposing them to be confirmed by larger experience) they would prove that the reproductive elements lay in the fibrine. But if cross- circulation gave a negative reply, it would be clear that the white foot was an accident of no importance to the theory of Pangenesis, and that the sterility need not be ascribed to the loss of hereditary gemmules, but to abnormal health, due to defibrinization and perhaps to other causes also. My operations of cross-circulation (which I call 2) put me in possession of three excellent silver-grey bucks, four excellent silver-grey does, and one doe whose operation was not successful enough for me to care to count it. One of my « does (B) had already undergone the operation uw, and I had another of my old lot (C (u)), which I left untouched. There were also three common rabbits, bucks, which were blood-mates to silver-greys, and four common rabbits, does, also blood-mates of silver-greys. From this large stock I have bred eighty-eight rabbits in thirteen litters, and in no single case has there been any evidence of alteration of breed. There 404: Mr. F. Galton’s Experiments in Pangenesis. [Mar. 30, has been one instance of a sandy Himalaya; but the owner of this breed assures me they are liable to throw them, and, as a matter of fact, as I have already stated, one of the does he sent me, did litter and throw one a few days after she reached me. The conclusion from this large series of experiments is not to be avoided, that the doctrine of Pangenesis, pure and simple, as I have interpreted it, is incorrect. Let us consider what were the alternatives before us. It seems @ prior: that, if the reproductive elements do not depend on the body and blood together, they must reside either in the solid structure of the gland, whence they are set free by an ordinary process of growth, the blood merely affording nutriment to that growth, or else that they reside in the blood itself. My experiments show that they are not independent resi- dents in the blood, in the way that Pangenesis asserts; but they prove nothing against the possibility of their being temporary inhabitants of it, given off by existing cells, either in a fully developed state or else in one so rudimentary that we could only ascertain their existence by inference. In this latter case, the transfused gemmules would have perished, just lke the blood-corpuscles, long before the period had elapsed when the animals had recovered from the operations. I trust that those who may verify my results will turn their attention to the latter possibility, and will try to get the male rabbits to couple im- mediately, and on successive days, after they have been operated on. This might be accomplished if there were does at hand ready to take them ; because it often happens that when the rabbits are released from the operating-table, they are little, if at all, dashed in their spirits; they play, sniff about, are ready to fight, and, I have no doubt, to couple. Whether after their wounds had begun to inflame, they would still take to the does, I cannot say ; but they sometimes remain so brisk, that it is probable that in those cases they would do so. If this experiment succeeded, it would partly confirm the very doubtful case of the pied young of the doe which died after an operation of cross-circulation (which, however, further im- plies that though the ovum was detached, it was still possible for the mother gemmules to influence it), and it would prove that the reproduc- tive elements were drawn from the blood, but that they had only a tran- sient existence in it, and were continually renewed by fresh arrivals derived from the framework of the body. It would be exceedingly instruc- tive, supposing the experiment to give affirmative results, to notice the gradually waning powers of producing mongrel offspring. APPENDIX I. It is important that I should give details of the operations of cross- circulation. I may mention that, having to deal with many rabbits, I distinguished them permanently by tattoomg bold Roman numerals in the inside of their ears. 1871.] Mr. F. Galton’s Experiments in Pangenesis. 405 I. Experiments of cross-circulation on one buck and two does, pure silver- greys, of a breed obtained from Mr. E. Royds, of Greenhill, Rochdale, the same breed as that on which all my u and w experiments had been made. ~ Oct. 19, 1870.—Silver-grey buck, O, out of doe A (u) by M (wu), and therefore own brother to the white-footed young oe small rabbit, just six months old. His blood-mate was a Yellow buck, lop-eared, white throat, probably one- fifth heavier than the silver-grey. I avoided unnecessary weighing, because it frightens the animals, and tends to interfere with the final success. At 12" 30™ I made cross-circulation ; flow was perfect; 12> 35™, continued perfect ; 12° 40™, perfect, but yellow to silver-grey perhaps the stronger ; 12" 44™, ditto; 12" 50™, perfect both ways; 12" 55™, ditto; 1°, ditto; 1" 5™, ditto; 12 74™, ditto. I then stopped and tied up. I tested the flow with a small and delicate but very simple pulse-meter on all these occasions, not liking to interfere overmuch with my fingers. I, however, used them at the commencement, at 12" 50™, and at 12 5™. Oct. 20, 1870.—Silver-grey doe, B (u), a fine large animal; her blood- mate was a- Common large grey lop-eared doe, about one-tenth heavier than the silver-grey. 1", cross-circulation established, apparently perfect ; I mean the throb- bing of the canula and artery were obvious ; 1" 6™, felt and found the flow quite good; 1" 12™, common to silver-grey quite good, vice versd poor ; 1" 15™, ditto; I disconnected and cleaned and removed clots and recon- nected. This I repeated several times; there was still much trouble in maintaining a proper flow from silver to common grey, but common to silver was always good. The operation continued till 1" 40™; then I dis- connected ; and as the silver-grey had received too much, I let her bleed to 4 drachms. Oct. 27, 1870.—Silver-grey doe, H, moderate size; her blood-mate was a Common large grey doe, certainly more than a tenth heavier than the silver-grey. ‘There was some trouble with her, as the carotid was abnormal, and three offshoots from it had to be tied before the canula could be inserted. 12” 48™, cross-circulation established, perfect pulse, but silver to common the fullest ; 12" 53”, perfect; 1°, silver to common perfect, vice versd rather poor; 1" 2™, ditto; 1°7™, common to silver stopped; I disconnected and cleaned and reconnected, and by 1° 12™ had reestablished perfect cross- circulation; at 1" 30™ I had stopped silver to common and made common to silver better; got five minutes good flow, then repeated cleanings and got three minutes more. My estimate at the close of the operation was that the silver-grey gave blood freely for thirty- five minutes, and received it freely for about the same time. II. Experiments of cross-circulation on two bucks and two does of a silver- grey breed, reputed pure, and looking well-bred animals, but liable to 406 Mr. F. Galton’s Experiments in Pangenesis. [Mar. 80, show russet marks. They were procured of Mr. Vipan, of March, Cam- bridgeshire, and are of the same breed as those on which Mr. Bartlett made his well-known experiments about the production of Himalayas (Proc. Zool. Soc. 1861). They are liable to throw “Sandy Himalayas,” as I found myself, as Mr. Bartlett also found, and as Mr. Vipan informs me is the case. I distinguish this breed by asterisks (*). Oct.6, 1870.—NSilver-grey buck, P*, moderate size; his blood-mate was a Common grey buck, with some russet on his back and white on his belly ; he was the larger of the two animals. 12" 50”, cross-circulation established, perfect ; 12° 55™, ditto, but silver to common, I think, a trifle the stronger; 12" 59”, ditto; 12 5™, common to silver very faint. I stopped them and cleaned out twice and succes- sively ; 1215”, good, but common to silver was the least good; 1" 25™, dis- connected. My estimate was that there had been an equivalent to fully twenty-five minutes, and perhaps thirty minutes, of capital flow both ways. Oct. 7, 1870.—Silver-grey buck, Q*, moderate size; his blood-mate was a Yellow buck, white belly, large. 11" 40", cross-circulation established; 11" 45”, quite good; 11” 50", good but not perfect; 11° 55™ good; 12” both stopped. Then I made several disconnexions and cleanings, and obtained short periods of success ; at 12" 35™ I finally stopped. My estimate was thirty minutes’ good run- ning: the silver-grey received more than his share; there was a slip in the operation, and five drachms of blood were lost between the rabbits; so I did not care to let the silver-grey bleed more. Oct. 6, 1870.—Silver-grey doe, 1*, moderate size; her blood-mate was a Common grey doe, large. 3> 40", cross-circulation was established ; 3" 44”, excellent; 3° 50™, ex- cellent; 3° 55”, excellent ; shortly after, something was twisted or other- wise went wrong, and both stopped. I had a good deal of trouble and but little further success. 'Ten drachms of blood was lost between the rabbits (partly by leakage of the canulez). Oct. 7, 1871.—Silver-grey doe, J*, moderate size; her blood-mate was a Yellow doe, dark about mouth, and also of moderate size. I afterwards became convinced she was simply a sandy Himalaya. At 2° 5™ established cross-circulation ; 2" 13”, quite good; 2” 20", ex- cellent ; 25 25™, excellent ; 2" 30™, ditto; 2°35”, ditto; 2" 40", ditto, then disconnected. An accident occurred at the end, by which the silver-grey lost four drachms of blood. APPENDIX II. Description of the method of performing the operations. It is essential to a fair chance of success that the operator should have a large and thriving stock of full-grown rabbits. They cannot be pro- cured at will in the market ; and young ones are so timid and tender that 1871.] Mr. F. Galton’s Haperiments in Pangenesis. 407 they are not fit to be operated on. The next essential point is an operating- table, with ample and proper apparatus for holding the rabbits easily but rigidly. It is most improper to subject a helpless animal to an operation without taking every precaution for its success, so as to minimize the ne- cessity for operating. ‘The chief hindrances to success are, entanglement of instruments, or the breaking loose of blood-vessels, both owing to an un- expected start ; also an animal will struggle violently, and become terrified if he is loosely held, hoping to get away, whilst if he is firmly secured he lies as though magnetized, without signs of fear or discomfort, and with his pulse and breathing perfectly normal. I regret extremely that, although I took pains to inquire, I did not at first hear of Czermak’s recently devised apparatus for holding the head. I began by the old plan of putting the animals in a bag and holding them, which was very unsatisfactory. Then I devised a plan of my own, which was good, but inferior to Czermak’s, and I therefore abstain from describing it. The latter, with recent modi- fications, can now be obtained at Mr. Hawkesley’s, 4 Blenheim Street, Bond Street, London, to whom, I should say, I have been greatly indebted for the care and thought he gave to successive and very numerous modi- fications of my instruments (far more numerous than I care to describe). A drawing of Czermak’s apparatus will be found in the ‘Berichte der K. Sachs. Geselischaft der Wissenschaften zu Leipzig,’ 1867, p. 212. For injections, I used a five-drachm ebonite syringe, whose stem was boldly graduated to drachms. The canula (to be inserted into the vein) was screwed into a light stopcock. ‘This was filled with water, which, so long as the cock ) was closed, did not run out for want of a Sa oo y vent-hole. When it was thrust in the vein ec eS and the vein was tied round it,I held the [—_—\_— ie : syringe full of blood near the open end of the Garrett stopcock, drove out all air by allowing a few drops of blood to fall into its mouth, then pushed its nozzle firmly in, opened the cock and began to inject, steadily and slowly, at the rate of about one drachm in twenty seconds. When the syringe was emptied, I turned the stopcock, withdrew it, rapidly filled it, emptied it and again filled it with warm water, and returning te the canula with the same precautions as before, I threw in about 7 drachm, to wash the blood out of the canula and adjacent vein. I do not think I lost more than three (or perhaps four) rabbits by injecting air, although the removals and replacements of the syringe were very numerous, often ten times in a single operation of the w kind. My apparatus consisted of a zinc warm-water bath, represented on the left of the diagram (p. 408) ; the vessels drawn to the right of it fitted into holes’ in its lid, as indicated by the letters. A is the basin to catch the supply blood ; 408 Mr. F. Galton’s Experiments in Pangenesis. [Mar. 80, it was whipped up by the whisk F; then poured into C, which consists of a short funnel with muslin below, resting in the top of a glass measure ; when the blood had strained through, the funnel and muslin were set on the top of D, to get them out of the way and, at the same time, to keep them warm for future use; B is the thermometer; E is a spill-case full of water to contain the syringe. In addition to these, I required a large slop- pail, a jug of hot, and another of cold water. ony \\ > ity a tet eas (Ox he | The sketch shows my latest outfit of basins and warm water for inject- ing. It was not perfected until I had nearly finished the experiments. Scrupulous cleanliness is requisite, and great orderliness; for the hazard lies, not in the performance of one difficult operation, but in making a mistake in some one of a great many easy operations. The course of an operation was as follows:—(1) secure the animal, (2) remove fur from neck, (3) anzesthetics, (4) expose jugular, (5) cut a slit in it and let the animal bleed as much as he can easily bear, about six drachms, (6) stop the flow with gentle pressure by spring forceps; the animal was then left fora minute while (7) Dr. Murie and Mr. Fraser divided the throat of the supply-rabbit, I catching the blood in a warmed basin and whipping it up, to defibrinize it, as it fell. I continued doing this while Dr. Murie was (8) inserting the canula; and when he was nearly ready he called to me, and I (9) filtered the blood, noting its amount, as a guide tu what I had to dispose of, (10) drew up a syringe full, (11) injected a con- venient number of drachms or half drachms, indicated by the graduations on the syringe-handle, (12) returned the overplus to the glass of supply- blood, (13) cleansed syringe and injected water, (14) let the rabbit bleed three or four drachms,—and then recommenced the series. I have not re- inserted in this description before (11) and (13) what I previously described about turning the stopcock &c.; nor have I spoken of the continual jotting down of notes in my case-book. 1871.] Mr. F. Galton’s Experiments in Pangenesis. 409 At the end of all, the vein was tied. It was, no doubt, the surest plan to avoid future hemorrhage, especially as the blood was defibrinized ; but the rabbits were apt to suffer from phlebitis, and I lost some thereby. Owing to the extreme rapidity and stiffness of the coagulation of rabbit’s blood, it is quite easy to estimate the quantity that may have been spilt on the operating-table. It has simply to be sponged into a measuring-glass, Cross-circulation would be a very easy operation in animals whose carotids were even a trifle larger than those of silver-grey rabbits; but it is difficult with these, because the smallest canula which can be used with propriety can only just be forced into the largest of them. It is no use operating with small canulee ; m every case, a layer of fibrine is sure to line the tube; if the bore is small this layer chokes it, while a layer of equal thickness in a larger tube leaves a free central passage. I found canule ;'; inch in diameter of bore were worthless; those I used were zz inch. If I were to operate again, I should not use silver-grey rabbits, on aecount of their smallness, but ‘‘ Belgian hare”’ rabbits. When the canulz are brought home together, the wire hooks, shown in the sketch, secure them; but I also slipped an India-rubber band over the tips of their handles. The cut ends of the artery were held open and stretched out by a pair of delicate curved forceps (a suggestion due to Dr. Murie), and the canula was pressed in (the shape of its mouth was the result of many trials and modifications), and a ligature was put on. In the diagram, A represents one pair of canulze, both opened and closed. B shows their position at the time of crossed circulation. It will be observed that each artery requires four pieces of apparatus, viz. two spring forceps to stop the blood, and two canule. Thus, when the throats were brought close toge- ther, to connect the arteries cross-wise, there were no less than eight 410 Dr. J. Stenhouse on Nitro-substitution [ Mar. 30, separate pieces at work in a deep hollow, close together, and attached to delicate arteries, none of which could be permitted to twist or interfere with each other. I append a reduced sketch of one of the two frameworks over which, as pre- viously described, I suspended these instruments, with attached counterpoises, and so avoided all con- fusion. Both pair of canule and two pair of forceps are here represented; they might be so arranged; but it is better to divide the instruments, equally, between the two frames. For removing clogs from the canule, I tried a great many plans, none with as much success as I could wish. I have, however, been able to extract clots from the artery itself, a good quarter of an inch beyond the canulee, with a wire whose end had been cut with a file into a delicate solid corkscrew. I washed out the canule, before reconnecting, with a thin stream of water sent through the quill of a small bird, which I had fastened, by help of a short India-rubber tube, to my syringe. The wounds require careful dressing, just like those of a man. The rabbits bear the operations wonderfully well, and appear to suffer little or no pain when the influence of the anzesthetics happens to have left them temporarily sensible. They are often quite frisky when released, and sometimes look as though nothing whatever unusual had happened to them, all through the time of their recovery. II. “Contributions to the History of Orcn.—No. I. Nitro-substi- tution Compounds of the Orems”*. By Joun Stenunoust, LL.D., F.R.S., &c. Received March 1, 1871. The action of nitric acid upon orcin has been studied by several chemists, but with comparatively negative results. Schunck + in this manner ob- tained a red resinous substance, which by further treatment with the acid was oxidized to oxalic acid; andin 1864 De Luynes { found that orcin dis- solved in cooled fuming nitric acid without evolution of nitrous fumes, and that the addition of water precipitated a red colouring-matter ; the long-continued action of the vapour of fuming nitric acid on powdered orcin likewise produced a red dye apparently identical with the above. These, however, were resinous uncrystallizable substances. Although under ordinary circumstances only resinous products are ob- tained by treating orcin with nitric acid, yet, when colourless orcin in fine * A Preliminary Notice with this title was published in the ‘Chemical News,’ August 26, 1870. + Ann, Chem. Pharm. vol. liv. p. 270. { Ibid. vol. cxxx. p. 34. 1871.] Compounds of the Orcins. 411 powder is gradually added to strong nitric acid cooled by a freezing-mix- ture, it dissolves with a pale brown coloration, but without the slightest evolution of nitrous fumes. If this solution be now slowly dropped into concentrated sulphuric acid cooled to —10°C., the mixture becomes yellow and pasty, from the formation of nitro-orcin, which is but slightly soluble in sulphuric acid. When this is poured into a considerable quantity of cold water, the nitro-body separates as a bright yellow crystalline powder, quite free from any admixture of resin. After numerous experiments the following was found to be the most advantageous process for the preparation of nitro-orcin. 6 grms. of colourless orcin were dissolved in 6 cub. centims. of boiling water, and when the solution had cooled to about 50° C., it was added in small portions at a time, and with constant stirring, to 40 cub. centims. of nitric acid, sp. gr. 1°45, which was maintained at a temperature of about — 10°C. by immer- sion in a good freezing-mixture. The solution, which was of a very pale brown colour, was now added, in a similar manner, to 120 cub. centims. of concentrated sulphuric acid, also maintained at —10° C. The pasty mass, after being allowed to stand for fifteen or twenty minutes in the freezing- mixture, was poured into a beaker containing 300 cub. centims. water and 400 grms. ice; the crude nitro-compound was then precipitated as a yellow or orange-coloured granular powder. The orcin employed in the prepara- tion of this nitro-compound was colourless, having been purified by dis- tillation 2m vacuo. The yield of crude nitro-orcin amounted to 150 per cent. of the weight of the orcin. The crude nitro-orcin was collected, washed with a little cold water, and purified by one or two crystallizations from boiling water (40 parts). It was thus obtained in large yellow needles, which are readily soluble in hot water and but slightly in the cold; the addition of a strong acid preci- pitates almost the whole of the nitro-orcin from its cold aqueous solution. It is soluble in alcohol, very soluble in hot benzol, and crystallizes out in great part on cooling ; it is less soluble in ether, and but moderately so in bisulphide of carbon. It dyes the skin yellow, like picric acid, but is tasteless. It volatilizes slightly at 100° C., melts at 162° C., and decom- poses with slight explosion immediately afterwards. When heated with concentrated sulphuric acid it dissolves, forming a deep yellow solution, which deposits crystals on cooling, and is immediately precipitated by water. It dissolves in hot strong nitric acid with evolution of nitrous” fumes and formation of oxalic acid. Like picric acid, when treated with calcium hypochlorite it yields chloropicrin at the ordinary temperature. Its aqueous solutions are coloured dark brown by ferric chloride, and com- pletely precipitated by lead subacetate. The analysis of the substance dried at 100° C. was made, with the fol- lowing results :— I. -335 grm. substance gave 400 grm. carbonic anhydride and :062 germ. water. 412 Dr. J. Stenhouse on Nitro-substitution [| Mar. 30, II. -306 grm. substance gave ‘366 grm. carbonic anhydride and -060 grm. water. III. -525 grm. substance gave ‘629 grm. carbonic anhydride and -096 grm. water. Theory. ae Li ink Mean. C,= 84= 32°43 32°58 32°63 32°68 32°63 no" o=" 198 2°06 2°18 2°03 2°09 Ne 42— 16:22 oe - i “i! O,=128= 49-42 259 100°00 These results correspond to the formula C, H, (NO,), O,, that of trinitro-orcin. It is a powerful acid, much resembling picric acid, but distinguished from the latter by the greater solubility of its salts. I pro- pose, therefore, to call this new substance ¢rinztro-orcinic acid. Potassium trinitro-orcinate.—This was readily prepared from trinitro- orcinic acid by dissolving it in a warm and rather concentrated solution of potassium carbonate. On cooling it solidified to a crystalline mass of fine needles of a deep orange colour, which after the removal of the mother- liquors by the vacuum filter, or by pressure, was purified by crystallization from hot water, in which it was very soluble. The salt dried at 100° was submitted to analysis. I. 300 grm. substance gave 155 grm. potassium sulphate. Theory. a. ae s— 3 re be Ko 78 22338 23°19 go 42 ves O,=128 Sys The result obtained agrees with formula C, H, (NOD, \ 0,. Sodium trinitro-orcinate.—This was obtained by adding trinitro-orcinie acid to a strong solution of sodium hydrate or carbonate until nearly neutralized, and purifying by recrystallization. It forms orange-coloured microscopic needles, strongly resembling the potassium salt. Ammonium trinitro-orcinate was prepared by adding trinitro-orcinic acid to moderately strong ammonia, in quantity insufficient to neutralize it, boil- ing for a short time, and then setting aside to crystallize. It forms deep- yellow silky needles, which are very soluble in water, but much less so in alcohol. 1871.] Compounds of the Orcins. 413 Barium trinitro-orcinate.—Trinitro-orcinic acid was dissolved in 400 or 500 parts of boiling water and an excess of barium carbonate added, the pale yellow solution filtered from the excess of carbonate and set aside. On cooling, the solution formed a semisolid crystalline pap, consisting of fine bright yellow needles of the barium salt. The air-dried salt lost 10°7 per cent. at 100°, and became of an orange-red colour, but regained its original colour on exposure to moist air. A barium determination was made of the salt dried at 100°. I. -235 grm. substance gave ‘139 grm. barium sulphate. II. *328 grm. substance gave *194 grm. barium sulphate. Theory. IL. Pe Mean. C, = 84 H, = 3 Ba’ =137 = 34°77 34°78 34°79 34°78 ING — 42 O,. =128 394 The orange-coloured anhydrous salt has the composition Sos Ne ); ah | O,, and the yellow needles cau: (NO.); } O,+3H,0. Calcium trinitro-orcinate, prepared by neutralizing the acid with calcic carbonate, is very soluble in hot water, and crystallizes out on cooling in in- terlaced yellow needles, which are rather soluble in cold water. It is but slightly soluble in hot alcohol; and the solution forms a gelatinous mass on cooling. Magnesium trinitro-orcinate is very soluble in cold water, but less so in spirit. It crystallizes in minute orange needles. Lead trinitro-orcinate.—This salt was prepared by dissolving the pure trinitro-orcinic acid in 1000 parts of water strongly acidulated with acetic acid, and adding a solution of lead acetate likewise strongly acidulated, when the lead trinitro-orcinate came out as a bright yellow crystalline pre- cipitate, consisting of tufts of microscopic needles, which are very tough and difficult to reduce to powder. It is almost insoluble in cold water, slightly soluble in hot. It is solubie in hot acetic acid, from which it crystallizes unaltered. It is insoluble in alcohol. If alcoholic solutions of trinitro-orcinic acid and lead acetate be mixed, the lead-salt is obtained as a yellow amorphous precipitate. Dried at 100° it gave the following estlta: _ I. -319 grm. substance gave -207 grm. plumbic sulphate. II. *536 srm. substance gave ‘348 grm. plumbic sulphate. III, -339 grm. substance gave ‘221 grm. plumbic sulphate. VOL. XIX. 21 A414 Dr. J. Stenhouse on Nitro-substitution [ Mar. 30, Theory. I. II. HI. Mean. Cc, = 84 H, = 3 Pi e e KY g, Pb = 207 = 44-62 44°34 44°36 44°54 44.4] Nav.) 42 ee O, = 128 464 Its composition is therefore represented by the formula C, H, (NO,), O De eee Copper trinitro-orcinate, formed by dissolving cupric carbonate in a strong aqueous solution of trinitro-orcinic acid, was with difficulty obtained in the crystalline state in the form of small reddish-brown needles, which are very soluble in water and alcohol, but are precipitated from their solution in the latter menstruum by ether. Zine trinitro-orcinate, formed from zinc oxide in a similar manner to the copper salt, is likewise very soluble in water and alcohol, and crystallizes in tufts of yellow needles. Silver trinitro-orcinate.—Trinitro-orcinic acid was dissolved in fifty times its weight of boiling water, an excess of silver oxide added, and, after boiling © a few minutes, filtered from the undissolved silver oxide. On cooling, the whole solidified to an orange-red gelatinous mass of the silver compound, which exhibited no signs of crystallization. It is moderately soluble in hot water ; and its solution gelatinizes on cooling. When boiled for any length of time its solution slowly decomposes. Dried at 100° it gave the following results :— I, °458 grm. substance gave *277 grm. argentic chloride. II. -398 grm. substance gave '241 grm. argentic chloride. Theory. I. II. Mean. Gi = 34 HL yeiatina yap 4 ig A Ae Gee 706 45°41 43°57 45°49 Nea AD OF 525 473 This corresponds to the formula C, i, elie O Ag, 2° Lthylie trinitro-orcinate.—Dry and finely powdered silver trinitro-orci- nate was digested with ten times its weight of ethylic iodide until the silver salt was completely decomposed, as shown by the pale yellow colour of the silver iodide formed, the excess of ethylic iodide distilled off, and the ethy} 1871.] Compounds of the Orcins. 415 trinitro-orcinate extracted from the residue by boiling alcohol, from which it crystallized in bright yellow prismatic needles. One or two recrystalliza- tions rendered it quite pure. It melts at 61°°5 C., and is very soluble in hot alcohol, from which, if the solution be concentrated, it is deposited as an oil that solidifies on cooling. The substance dried iz vacuo was submitted to analysis. I. -189 grm. substance gave *290 grm. carbonic anhydride and ‘078 grm. water. Theory. 7: Ce — 122 SI 41°85 Bo FS ATS 4°58 ee — ae —— oo 0. ——- oe 40-00 315 100-00 It may therefore be represented by the formula C, H, (NO,), (C, H,), Methyl trinitro-orcinate was prepared in a manner precisely similar to that above described, substituting methylic for ethylic iodide. Like the ethyl compound, it forms bright yellow crystals, which, however, have a somewhat higher melting-point, viz. 69°°5 C. ; O,. Trinitro-resoreinic Acid. As it seemed important to ascertain if the homologues of orcin yielded compounds similar to trinitro-orcin, I submitted resorcin to the action of nitric and sulphuric acids in a manner precisely similar to that above de- scribed for the preparation of trinitro-orcin. The resorcin employed was prepared from Galbanum by the excellent method given by its discoverers, Hlasiwitz and Barth*, substituting, however, sodium hydrate for potassium hydrate. After purification it was treated with nitric and sulphuric acids, employing the proportions and methods detailed in the preparation of trinitro-orcin. As might have been expected, the yield of crude substance was larger, being 180 per cent. of the resorcin employed. It was collected, washed with cold water, and puri- fied by one or two recrystallizations from boiling water (30 parts). It is of a paler colour than the corresponding orcin compound, and crystallizes in leafy plates. It melts at a higher temperature, viz. 175°°5 C., and is more soluble than trinitro-orcin; 156 parts of water dissolve one of trinitro- resorcin at 14° C., but the presence of even a small proportion of one of the stronger acids renders it almost insoluble. Dried at 100° it gave the following results :— * Ann. Chem. Pharm. vol. exxx. p. 354. 416 Dr. J. Stenhouse on Nitro-substitution [Mar. 30, I. :384 grm. substance gave *412 grm. carbonic anhydride and *043 grm. water. II. -418 grm. substance gave ‘451 grm. carbonic anhydride and ‘051 grm. water. ; Theory. I. II. Mean. C, = 72 = 29-39 29°27 29°43 29°35 H,= 3 = 1:23 1-30 1°36 1:33 N,= 42 = 17°14 O, = 128 = 52:24 245 ~=100°00 This corresponds to the formula C, H, (NO,), O,, that of trinitro- resorcin. Barium trinitro-resorcinate was prepared by dissolving trinitro-resorcin in 100 parts boiling water and adding an excess of baric carbonate. The filtered solution, on cooling, deposited the barium compound in minute rhomboidal plates of a pale yellow colour. It is much more soluble than the corresponding trinitro-orcin compound. The crystals contain three equivalents of water of crystallization, which they do not lose at 100° C. ; but when gently heated on platinum foil they assume an orange-red colour from the loss of water of crystallization, and at a higher temperature ex- plode with extreme violence, perforating the foil. Both trinitro-orcinic and resorcinic acids and their salts explode with far greater violence than picric acid and its compounds. A barium determination of the nitro-resorcinate, dried at 100°, yielded the following results :— I. :409 grm. substance gave ‘220 grm. baric sulphate. II. 444 grm. substance gave ‘239 grm. baric sulphate. Theory. i II. Mean. Tp aaah Eee hy a be is i Ba" — 137:2'= 31°59 31°63 31°66 31°64 N, = 42 i O, = 176 434°2 The formula is therefore C, H(NO,), | oHAKNO), } 0,+3H,0. Lead trinitro-resorcinate.—The addition of a solution of acetate of lead - to an aqueous solution of trinitro-resorcinic acid gave a yellow gelatinous precipitate of lead trinitro-resorcinate. It was found best, however, to pre- 1871.] Compounds of the Orcins. 417 pare it by boiling a solution of one part of trinitro-resorcinic acid in 200 of water, with a slight excess of lead carbonate, when the lead compound was deposited on cooling in the form of deep yellow needles. It is but slightly soluble in water, very soluble in acetic acid, and precipitated therefrom by the addition of alcohol. Subacetate of lead completely precipitates solu- tions of trinitro-resorcinic acid. | Silver trinitro-resorcinate.—This was prepared in a manner similar to the trinitro-orcinate. A solution of one part of the pure acid in 75 of water was boiled for a short time with a slight excess of oxide of silver and filtered. On cooling, the silver-salt was deposited in long fine needles of a yellowish- brown colour. They crystallize readily from boiling water, in which they are much more soluble than the corresponding trinitro-orcinate. Dried at 100° it gave the following results :— I. -456 grm. substance gave *284 grm. chloride of silver. II: -416 grm. substance gave ‘260 grm. chloride of silver. Theory. T. II. Mean. oo I Il . NI — 216 = 47:07 46°87 47°04 46°96 Onz> SQ hill bo 2 pr The analyses correspond to the formula C, H (NO,), } O.. O2 Trinitro-beta-orcinic Acid. Beta-orcin, C, H,, O,, when treated with nitric and sulphuric acids as above described, gives a yellow substance, which appears to be the cor- responding nitro-compound of beta-orcin ; but from the small amount of material at my disposal, I am at present unable to accurately determine its properties. From some experiments I have made, the action of reducing agents, nitrous acid, &c. upon these nitro-compounds promises very interesting results. I am at present investigating this subject. My thanks are due to Mr. Charles E. Groves for the efficient assistance he has rendered in conducting the above investigation. The Society adjourned over the Easter Recess to Thursday, April 20th. 418 Presents. [ Mar. 2, Presents received, March 2, 1871. Transactions. London :—Royal Asiatic Society. Journal. New series. Vol. V. Part 1. 8vo. London 1870. The Society. National Association for the Promotion of Social Science. Transac- tions. Newcastle Meeting, 1870. Edited by Edwin Pears. 8vo. London 1871. The Association. Vienna :—Kaiserlich-Konigliche geologische Reichsantalt. Jahrbuch. Jahrgang 1870. No. 3. 8vo. Wien 1870. Verhandlungen. No. 10-12. 8vo. Wien 1870. The Institution. Reports, &ce. Albany :—State of New York. Fifty-second Annual Report of the Trustees of the New York State Library. 8vo. Albany 1870. Eighty-first and Eighty-second Annual Report of the Regents of the University. 8vo. Albany 1868-69. Twenty-second Annual Report on the Condition of the State Cabinet of Natural History. Svo. Albany 1869. Speeches and Reports in the Assembly of New York at Annual Session of 1838, by D. D. Barnard. 8vo. Albany 1838. Report of John Jay on the National Cemetery at Antietam. 8vo. Albany 1868. Annual Report of the General Agent for the Relief of Sick and Wounded Soldiers of the State of New York. 8vo. Albany 1865. Compound and Comminuted Gun-shot Frac- tures of the Thigh, by J. Swinburne. 8vo. Albany 1864. The State of New York. London :—Royal College of Physicians. List of the Fellows, Members, Extra Licentiates, and Licentiates. 8vo. London 187]. The College. New York :—Cooper Union for the Advancement of Science aud Art. Fifth, Seventh, and Tenth Annual Report of the Trustees. 8vo. New York 1864-69. The Trustees. Association for Improving the Condition of the Poor. Twenty-fifth Annual Report. 8vo. New York 1868. The Association. Washington :—Surgeon-General’s Office. Report on certain points con- nected with the Histology of Minute Blood-vessels, by J. J. Wood- ward. 4to. Washington 1870. Report on the Oxy-Calcium Light as applied to Photo-Micrography. 4to. Washington 1870. Twenty- four Photographs of Microscopic Objects. The Surgeon-General. Wellington :—Registrar-General’s Office. Statistics of New Zealand for 1869. fol. Wellington 1870. The Government of New Zealand. 1871.] Presents. 419 Goodeve (T. M.) The Elements of Mechanism. 12mo. London 1871. The Author. Grove (W.'R.), F.R.S. Die Verwandtschaft der Naturkrafte. Deutsche autorisirte Ausgabe, herausgegeben durch EH. von Schaper. 8vo. Braunschweig 1871. The Author. Roscoe (H. E.), F.R.S. Spectrum Analysis. Six Lectures delivered in 1868 before the Society of Apothecaries of London. 8vo. London 1870. Die Spectralanalyse. Autorisirte deutsche Ausgabe, bearbeitet von C. Schorlemmer. 8vo. Braunschweig 1870. The Author. March 9, 1871. Transactions. Berlin :—Akademie der Wissenschaften. Monatsbericht, August—De- cember 1870. 8vo. Berlin. The Academy. Edinburgh :—Royal Scottish Society of Arts. Transactions. Vol. VIII. Part 2. 8vo. Edinburgh 1870. The Society. Glasgow :—Philosophical Society. Proceedings, 1868-70. Vol. VII. No. 1, 2. 8vo. Glasgow 1869-70. The Society. London :—Royal United Service Institution. Journal. Vol. XIV. No. 58-61. 8yo. London 1870. The Institution. Observations. Leyden :—Annalen der Sternwarte, herausgegeben von F. Kaiser. Band Il. 4to. Haag 1870. Prof. Kaiser. Adams (J. W.) American Interoceanic Ship Canals. 8vo. New York 1870. The Author. Anderson (B.) Narrative of a Journey to Musardu. 8vo. New York 1870. The Author. Benson (Wm.) Manual of the Science of Colour. 12mo. London 1871. The Author. Du Bois Reymond (Emil) Speech on the German War, Aug. 30, 1870. 8vo. London 1870. The Author. Hitchcock (C. H.) First Annual Pee upon the Geology and Minera- logy of the State of New Hampshire. 8vo. Manchester (U. 8.) 1869. The Author. Lea (Isaac) Index to Vol. XII., and Supplementary Index to Vol. I. to’ XI. of Observations on the Genus Unio. 4to. Philadelphia 1869. The Author. Lewis (Tayler) State Rights: a Photograph from the Ruins of Ancient Greece. 8vo. Albany 1865. The Author. 4.20 Presents. [ Mar. 16, Packard (A. 8.) Record of American Entomology for the year 1868. 8yvo. Salem 1869. (2 copies.) The Author. Shettle (R. C.) The Nature of the Vital Force shown from the growth of the Body. 8vo. London 1871. The Author. Todd (C.) Meteorological Observations in South Australia, 1869. fol. Adelaide. The Author. Trembley (J.B.) Annual Meteorological Synopsis for 1866. 8vo. Toledo Ohio. The Author. Engraved Portrait of Alexander MacLeay, F.R.S., from a painting of Sir Thomas Lawrence by C. Fox. J. J. Bennett, F.R.S. March 16, 1871. Transactions. Caracas :—Sociedad de Ciencias Fisicas y Naturales. Vargasia, Boletin, No: 7. Svo. Cardeas 18/0. ~ The Society. London :—Mathematical Society. Proceedings. No. 25-31. 8vo. London 1870. The Society. Quekett Microscopical Club. Journal. No. 11-13. Fifth Report. 8vo. London 1870-71. The Club. Royal United Service Institution. Journal. Vol. XIII. Appendix. 8vo. London 1870. The Institution. Society of Antiquaries. Archeeologia. Vol. XLIII. Part 1. 4to. Lon- don 1871. The Society. Mauritius :—Meteorological Society. Transactions. Vol. I1., IV. 8vo. Mauritius 1855-59. Proceedings, 1861. 8vo. Mauritius. The Society. Montreal :—M°Gill College and University. Annual Calendar. Session of 1870-71. 8vo. Montreal 1870. The College. Newcastle-upon-Tyne. Chemical Society. Proceedings (pp. 88-172). 8vo. Newcastle 1869-70. The Society. Kops (Jan) en F. W. van Eeden. Flora Batava, 211-215 Aflevering. 4to. Leden. The Minister of the Interior of the Kingdom of the Netherlands. Lankester (Dr.), F.R.S. Seventh Annual Report of the Coroner for the Central District of Middlesex. 8vo. London 1871. The Author. Laughton (J. K.) Physical Geography in its relation to the prevailing Winds and Currents. 8vo. London 1870. 1871. | Presents. 421 Todd (Charles) Report on the determination of the Boundary Line of the Colonies of South Australia and New South Wales. fol. Adelaide 1869. The Author. Wright (E.P.) Spicilegia Biologica: or Papers on Zoological and Bo- tanical Subjects. Part 1. 8vo. London 1870. The Author. March 23, 1871. Transactions. Alnwick :—Berwickshire Naturalists’ Club. Proceedings. Vol. VI. No. 2. 8vo. Alnwick 1870. The Club. Calcutta :—Asiatic Society of Bengal. Journal, 1870. Part 1. No.3; Part 2. No. 3, 4. 8vo. Calcutta. 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On Force and Matterin relation to Organization. 8vo. Hdind. 1869. Researches on the Blood. 4to. London 1868. The Author. Gamgee (A.) and D. Maclagan. On the Alkaloids contained in the Wood of the Bebeeru or Greenheart Tree. 4to. Hdinb. 1869. The Authors. Gamgee (A.) and J. Dewar. On Cystine (C,H, NO,S). 8vo. Hdinbd. 1870. The Authors. March 30, 1870. Transactions. Berlin :—Physikalische Gesellschaft. Die Fortschritte der Physik im Jahre 1867. Jahrgang 23, &vo. Berlin 1870. The Society. Kiel :—Universitat.. Schriften 1858. Band V.; 1869. Band XVI. 4to. Kiel 1859-70. The University. Leipzig :—Astronomische Gesellschaft. Publication X. Tafeln der Am- phitrite, von E. Becker. 4to. Leepzig 1870. The Society. Paris :—Faculté des Sciences. Theses. No. 317-327. Svo and 4to. Paris 1870. The Faculté des Sciences. Observations and Reports. Berlin:—Berliner Astronomisches Jahrbuch fur 1873, herausgegeben von W. Foerster. 8vo. Berlin 1871. The Observatory. Punjab :—Report on the Meteorology of the Punjab for the year 1869, by A. Neil. fol. Lahore 1870. The Author. Hill (C. J.) Sur une forme générale de développement et sur les In- tégrales définies. 4to. Lund. The Author. Ratjen (H.) Geschichte der Universitat zu Kiel. 8vo. Kiel 1870. Ge- schichte der Kieler Universitatsbibliothek. 4to. Avel 1862-3. The Author. Ratjen (E.) De Hydrotherapia Typhi Abdominalis. 4to. Kile 1864. The Author. Wackerbath (A. F. D.) On the Great Pyramid of Gizeh. 4to. Southampton 1871. The Author. 1871.] Mr. J. R. Hind on Transits of Venus. 423 April 20, 1871. Dr. WILLIAM HUGGINS, Vice-President, in the Chair. The following communications were read :— I. “Note on the circumstances of the Transits of Venus over the Sun’s Disk in the years 2004 and 2012.” By J. R. H1np, F.R.S. Received March 1, 1871. While preparations are being made by astronomers of various nations for the observation of the approaching transit of Venus over the sun’s disk in December 1874, it may be of interest to know under what conditions the pair of transits in the twenty-first century will take place. This conside- ration has induced me to make a careful calculation of the circumstances of the transits in 2004 and 2012, from M. Leverrier’s Tables of the Sun and Planet, which at present are extremely accurate, and which, there can be little doubt, will closely represent the phenomena to be witnessed in those years. The calculations have been made entirely by myself, but with every precaution to avoid error, and I have confidence in the results. The following are the resulting elements of the transit in 2004 :— Greenwich mean time of conjunction in right ascension 2004, June A 20 a1” 28°°8. Right ascension of Sun and Venus .... 7 6 50 28°6 Declination of Sun .... +22 53 20°4 a Venus .. +22 42 52°3 Horary motionin R.A. .... Sun.... 2 35:07 A yeaa. Venlugn'! . —1 37°40 Horary motion in declination. Sun.... +0 13-00 6 fe Venus .. —0 43°83 Semidiameter of Sun.... 15 45°74 oe Venus .. 28°75 Horizontal parallax ........ Sui orga 8°78 Siege SRT Res ak? Venus .. 80°85 Log. distance of Venus from the Earth. . 946069 Equation of time .. 1” 1586 (additive to mean time). Hence, for the centre of the earth,— d hm s First external contact ... June 7 17 3 43 at 115-0 from N. towards E. , internal _,, » 17 22 85 at 118-0 io For the Second internal ,, pS 23 5 40 at 2146 5 ee Sin, Cxterhal \.: i 23 24 32 at 217°5 9 ne And / being the geocentric latitude, p the radius of the earth at any place, VOL. XIX. | 21 424, Mr. J, R. Hind on Transiis of Venus. [Apr. 20, and A the longitude from Greenwich +E., — W.., the reductions for paral- lax will be obtained from | ad. 7am is at, Ist ext. cont....June7 17 3 43+(2:2198]o.sin 7—[2-5932]. p . cos?.cos(A+176 32). Ist int. cont. = 17 22 85+ [2°2571 ]o . sin 7— [2°5765] . 9 . cos7 . cos(A +182 38). 2nd int. cont. “A 23 5 40—[2°5090]o .sin/+[2°4353] . p.cos7.cos(A+ 47 17). 2nd ext. cont. » 28 24 32—[2°4928]o.sinJ+[2-46381]..cosZ.cos(A+ 54 35). For the Royal Observatory, Greenwich, I find :-— : d-h m-s First external contact, June 7 17 9 56 »» Internal 5 ~ 17 28 of Mean times at Secondinternal _,, Be DEN hot Greenwich. ss | €xternal.. .,, ee Tat 22 wlio Therefore the entire transit will be visible at Greenwich. Similarly the elements of the transit of 2012 are found to be :— Greenwich mean time of conjunction in right ascension 2012, June 54 13% 4™ 44°°3, Right ascension of Sun and Venus .... 74 31 11-9 Declination of Sun .... +22 40 24:1 me Venus.... +22 50 3°0 Horary motion tn B.A... Sin. 2.2. 2 34°67 . ite Venus.... —1 37°70 Horary motionin declination. Sun .... +0 15°23 ae bes Venus.... —0 45:37 Semidiameter of Sun .... 15 46°01 = Veaise -. 28°77 Horizontal parallax........ SUG tas eae 8°76 ae hag es ee OS Venus,... 30°86 Log. distance of Venus from the Earth.. 9°46042 Equation of time .. 1” 19*& (additive to mean time). Hence, for the centre of the earth,— doh” aa os First external contact ... June 5 10 22 11-at 40°3 from N. towards E. », internal _,, F 10 39 56 at 37°8 ] For the Second internal ,, o 16 42 6 at 293°1 q a 5.) external’, 4 17 0 Oat 290°5 + And, with the same notation as before, I find for the reductions for parallax,— an mn 8 Ist ext. cont. ... June 5 10 22 11+[2°4536] p . sin /—[2°4582] ,o.cos/.cos (A+41 28). Ist int. cont. 4 10 39 56+ [2°4838] po . sin /— [2:4558] .p.cosZ. cos (A+43 52). 2nd int. cont. 16 42 6—[2°1301]p.sin/+ [2°5968] .p.cosZ7.cos(A—10 57). 2nd ext. cont. a 17 0 O—[2°1158] p.sin/+ [25825] .p.cosd.cos(A— 6 28). 1871. | Dr. Divers on Salts of Nitrous Oxide. 425 At Greenwich the egress only will be visible. he i) aS Last internal contact, June 5, at 16 44 et Mean times at » external Ae Me LE Nie 5 Greenwich. The sun will rise at 15" 46”. II. “On the Existence and Formation of Salts of Nitrous Oxide.” By Epwarp Divers, M.D. Communicated by Professor W. Opiine, M.B., F.R.S. Received March 2, 1871. 1. Metallic sodium thrown on a solution of an alkali nitrate was found by Schénbein* to reduce it to nitrite. He contented himself, however, with merely detecting the nitrite by the iodide and starch test. By using the sodium in the form of amalgam the complete reduction of the nitrate to nitrite can be readily effected, and silver nitrite freely precipitated from the solu- tion by first neutralizing it with an acid and then adding silver nitrate. 2. But so soon as nitrite is thus formed by the sodium, it itself begins to suffer reduction, as well as the remaining nitrate, by the action of more sodium. This reduction of the nitrite is rendered evident by the efferves- cence which attends it, the gas given off consisting of pure nitrous oxide, If excess of sodium amalgam be gradually added to the nitrate solution, and its action moderated by keeping the vessel containing the mixture in a stream of cold water, the effervescence only becomes very lively when the sodium added has nearly reached the proportion of two atoms to one of the nitrate used. When four atoms of sodium have been oxidized by the solution, the further addition of it is without effect ; no more effervescence takes place, and the sodium remains unchanged in the mercury. 3. The very alkaline liquid which is left by the reaction contains a new salt, though in relatively small quantity—the salt of nitrous oxide. The action of sodium on sodium nitrate may therefore be thus formulated :— Ist stage: Na} O+Na=Ne |} O+Na,0. NO _N Qnd stage: NC OLNa=N, } O4Na,0. As regards the escape of nitrous oxide during the reduction, this is ex- plained by the reaction on each other of two molecules of the new salt, under the influence of the heat produced by the oxidation of the sodium, thus :— N N N Na Nat O+Na} O=N} O-+N: Cay * Hrdmann’s Journ. fiir prakt. Chemie, vol. lxxxiv. (1861) p. 202. ft When ammonium nitrate is employed instead of sodium or potassium nitrate, the action of the sodium is the same; and it is here interesting to point out that ammo- nium nitrate is an exception to the conclusion at which Gay-Lussac and Thénard arrived (Journ. de Physique, vol. lxix. 1809, p. 463), after they had tried the carbonate, chlo- 2u2 426 Dr. Divers on Salts of Nitrous Oxide. [Apr. 20, 4, After neutralizing the alkaline liquid by acetic acid, it gives a yellow, pulverulent precipitate with silver nitrate. This precipitate, when thoroughly washed from its saline mother liquor, is almost as insoluble in water as silver chloride ; for hydrochloric acid gives no immediate opalescence with water filtered through it. It is quite stable below 100° C., or a little lower than this, and it may be washed with hot water without change. It is also un- affected by light, or by exposure to a pure atmosphere, even when in contact with paper. It is but very sparingly soluble in acetic acid ; so that this acid may be added in excess to the original alkaline liquid without removing its property of being precipitated by silver salts. It is soluble in ammonia and ammonium carbonate, from solution in either of which it can be again thrown down by acetic acid, or by cautious neutralization of the ammonia ~ by dilute nitric or sulphuric acid, or by the volatilization of the ammonia. It is soluble in either dilute nitric or sulphuric acid, and without immediate decomposition ; and it can be reprecipitated from its solution in either of these acids by the cautious addition of ammonia or ammonium carbonate, or by the free addition of sodium carbonate or sedium hydrate, in either of which it is insoluble. It is immediately oxidized by concentrated nitric acid, copious red fumes being produced. Moderately diluted nitric, sul- phuric, or hydrochloric acid decomposes it, with the evolution of nitrogen, and the production of apparently both nitrous and nitric acids in the solu- tion. It is also decomposed by soluble chlorides and by hydrosulphurie acid. When precipitated from the original liquid, it sometimes becomes dark-coloured ; but this change is due to the formation of a black matter derived from the sodium or naphtha and the silver acetate. After washing it, dissolving it in very dilute nitric acid, and filtering the solution, it may be reobtained by the cautious addition of ammonia, or by the addition of ammonia to alkaline reaction and then a little acetic acid, in a condition in which it is no longer liable to discoloration. It is decomposed by a mode- rate heat into nitric oxide, metallic silver, and a little silver nitrate—in this respect resembling silver nitrite. My experiments on silver nitrite, about being published, show that nitric oxide may serve as a carrier of atmospheric oxygen to silver nitrite ; and it is therefore most probable that in this case also some of the nitric oxide liberated serves to carry a little oxygen to the still undecomposed new silver-salt. During its decomposition by heat it does not fuse or exhibit any other change except that from a bright yellow to a silver-white colour. After a red heat nothing remains but pure silver. 5. The following determinations of the amount of silver in the salt have been made :— I. -3317 grm., dried at a gentle heat, was suspended in water and digested ride, phosphate, and sulphate, that any ammonium salt would give ammonium amal- gam with sodium amalgam. Ammonium nitrate yields no ammonium amalgam with sodium amalgam; more than this, the presence of a nitrate prevents the formation of this body by other salts of ammonium. 1871. | Dr. Divers on Salts of Nitrous Oxide. 4.27 with hydrochloric acid. The silver chloride weighed °3386 grm.=°2549 grm. silver. II. :5703 grm. of some of the salt which had been dissolved in ammo- nia, filtered, and precipitated by acetic acid, was dissolved in dilute nitric acid and treated with hydrochloric acid. It yielded °5858 grm. silver chloride=°4410 grm. silver. III. -9462 grm. of some of the salt which had been dissolved in nitric acid, filtered, and reprecipitated by ammonia, was dissolved in very dilute nitric acid and precipitated by hydrochloric acid. It gave :9722 grm. chloride=°7318 grm. silver. IV. °6111 grm. of the same preparation as the last was heated at first moderately and then to redness. It left 4737 grm. silver. V. °3685 grm. kept for sixty hours at a temperature varying from 100° to 175°, left a residue weighing *2921 grm., of which *2775 grm. was metallic silver and the rest silver nitrate=:0093 grm. silver. VI. °5937 grm. heated moderately till red fumes ceased to appear yielded "4274 orm. silver and ‘0557 grm. silver nitrate='0354 grm. silver. The percentage numbers for the silver found and that required by the formula NOAg are: Cale. £ II. OE IV. Vi VI. MoO 2108 7G 3301 FP S4 TEAS [EES A F908 so that there can be no doubt as to the composition of the salt, although the silver comes out about one per cent. too low. But in several of the samples traces of brownish or black matters were detected on solution ; and in the last preparation analyzed, the presence of a little moisture was de- tected, an attempt to expel which in some of the unused salt by a stronger heat caused partial decomposition. 6. If the product of ,the ultimate action of seu, on the nitrate be treated with acetic acid, as directed, until it is neutral to test-paper, it gives no precipitate with any metallic solution except that of silver, so far at least as trial has yet been made. But the precipitation of the silver-salt leaves the solution of an acid reaction to litmus; and even if the solution before precipitation be rendered a little alkaline to litmus, it will, after precipitation, generally react slightly acid. The reason of this is clearly that the sodium salt has a markedly alkaline reaction ; and this is further shown to be the case by adding some of the washed silver-salt to a solu- tion of potassium or sodium chloride, which it at once renders alkaline in reaction to litmus. To obtain a solution of the salt free from acid or caustic alkali, the original alkaline liquid is to be treated with acetic acid in successive quantities until it just ceases to yield a brown precipitate with silver nitrate. Such a solution will yield the yellow silver-salt with silver nitrate as before, and also precipitates with the salts of most of the com- mon metals. Instead of acetic acid dilute nitric acid may be used in this method for thus neutralizing the caustic soda, with the same result as to 428 Dr. Divers on Salts of Nitrous Oxide. [Apr. 20, the alkalinity of the solution to test-paper, and its capability of being pre- cipitated by many metallic salts. | 7. The following reactions having as yet been only observed with a solution thus obtained, it is possible that some 1 them may not be due simply to the new acid :— Barium chloride gives no precipitate. Lead acetate gives a cream-white flocculent precipitate, which generally, on standing, changes to a very dense, full yellow precipitate. This pre- cipitate is unchanged by boiling in water or in its mother liquor, is soluble in acetic and other acids, slowly, if at all, affected by ammonia or sodium carbonate, and instantly decomposed by caustic soda. Mercurie chloride gives a cream-white flocculent precipitate. Mercurous nitrate gives a blackish-grey precipitate, not improbably a mixture of mercury and the mercuric salt. Cupric sulphate, a yellowish olive-green flocculent precipitate, soluble in acids and ammonia, insoluble in caustic soda, and unaffected by boiling in water or its mother liquor. The colour of this precipitate closely re- sembles the colour of a copper-salt mixed with a nitrite. Zine chloride gives a white precipitate. Manganese chloride gives a whitish precipitate. Nickel chloride gives a greenish, almost white precipitate. Cobalt nitrate gives no precipitate (?). Alum gives a white precipitate. Ferric chloride gives a slight reddish-brown precipitate. Ferrous sulphate gives a whitish precipitate, instantly darkening to dirty blackish green and eventually reddish brown. On addition of ferric chloride effervescence slowly commences; and with ferrous sulphate the same thing happens, but still more slowly. It is very probable that the iron and aluminium precipitates are simply hydrates; and if so, the action of this salt mm these cases closely resembles that of a carbonate. Silver nitrate behaves as already described. Sodium chloride gives an alkaline solution with the silver-salt, which is changed to chloride. Ammonium chloride gives the same result as sodium chloride, but the solution at once evolves ammonia. The existence, therefore, of the am- monium salt of the new acid is problematical. Potassium permanganate gives the beautiful changes of colour from its own violet, through purple, blue, and chrome-green, to manganate green, and then a brown precipitate. The exhibition of this series of colours is more certain in the presence of a little caustic alkali. In this reaction the new salt resembles a nitrite, but it is much more sensitive than this. Potassium iodide gives no reaction; it does with nitrite. Todine solution is decolorized immediately ; so that if a nitrite, not in excess, is added to a solution of the new salt, the addition of starch and potassium iodide produces no coloration. 1871.] Dr. Divers on Salts of Nitrous Oxide. 429 The solution acidified with acetic or hydrochloric acid still gives no re- action with potassium iodide, decolorizes iodine solutions, and prevents the action of a nitrite on an iodide. The acidified solution gives no coloration with ferrous sulphate. In con- tact with strong sulphuric acid, the mixture gives the coloration like a nitrate. As is well known, a nitrite, even without addition of acid, gives an immediate colour with ferrous sulphate. The acidified solution immediately decolorizes potassium permanganate. The acidified solution does not reduce potassium dichromate. The solution which has been neutralized with nitric acid instead of acetic acid will not do for the iron and iodine tests, as this behaves, so far as it has been tried, as though it contained a nitrite. The acidified acetic-acid solution, when heated, evolves nitrous oxide. Here again, therefore, the new salt is analogous to a carbonate,— 2NOH=N,0+0H,,. 8. When silver nitrite is heated until a greenish-yellow, semifused mass remains, and this is washed out with water, the residue consists of metallic silver and a little bright yellow matter, unaffected by light, soluble in am- monia, and decomposed by boiling in water, as will be found described in my paper on the action of heat on silver nitrite already referred to. From the properties of this yellow substance, and from the manner in which it is formed, it is probable that it is the silver-salt of the new acid; but in consequence of the small quantity of it obtainable, and of the admixture of this with metallic silver, a fuller examination of it has not been attempted. If it be this salt, its formation is analogous to that of silver nitrite by heating silver nitrate. 9. There is also reason for believing that Hess * came across this salt by first treating a solution of barium nitrate which had been deoxidized by heat with a solution of silver sulphate and evaporating the mixture, and then decomposing the crystals thus obtained by the action of water. 10. In his ‘Researches on Nitrous Oxide’+, Sir Humphry Davy de- scribed some experiments by which he obtained what appeared to him to be a combination of nitrous oxide with potash. THe prepared it by ex- posing a mixture of solid potassium hydrate and potassium sulphite to the prolonged action of nitric oxide, dissolving the resulting product in water, crystallizing out the potassium sulphate formed, and then evaporating to dryness. The mass thus obtained evolved when heated pure nitrous oxide, amounting to about a fourth of its weight. Since then, however, Pelouze { has obtained, by a modification of Davy’s method, the alkali nitrosulphates; and it seems to be now universally * Pogg. Ann. vol. xii, (1828) p. 257. tT Researches, Chemical and Philosophical, chiefly concerning Nitrous Oxide (1800). Res. ii. Div. i. sect. 6, pp. 254-277. { “Sur quelques combinaisons d’un nouvel Acide formé d’ Azote, de Soufre et d’Oxy- géne,” Ann, de Chim. et de Phys. vol. lx. (1835) p. 151. 430 Dr. Divers on Salts of Nitrous Oxide. — [Apr. 20, believed that Davy must have in reality obtained a nitrosulphate and not a simple salt of nitrous oxide. I have not yet had time to repeat Davy’s experiments myself, but I wish to point out one well-marked and essential difference between the body obtained by Davy and Pelouze’s nitrosulphate, which is that, whereas the former body evolved pure nitrous oxide when heated, the latter gives off nitric oxide; and also that, according to Davy’s experiments, Pelouze’s modification of the former’s process would be fatal to its success in forming the salts of nitrous oxide. 11. There is some difficulty in selecting an appropriate name for the new acid. That of hyponitrous acid naturally suggests itself, as being framed according to the usual method of naming a rising series of oxygen acids, and as associating the new acid with the similarly constituted acid of chlorine; but I feel that in naming the nitrous-oxide acid regard ought to be had to the possible existence of salts of nitric oxide, in which several chemists have believed, indeed, and on better evidence, I think, after a perusal of some of their papers, than is generally supposed. Now, if the nitric-oxide acid should be discovered, and if the term ‘“‘hyponitric”’ is to be retained for the acid intermediate to the nitrous and nitric acids, the term “‘hyponitrous”’ would belong by analogy to the nitric-oxide acid rather than to the new acid. This difficulty, however, will vanish if the term hyponitric be allowed - to fall out of use and that of nitroso-nitric, already adopted by several . chemists, be generally substituted for it as the name of the nitrogen-per- oxide acid; for then, the term ‘“‘hyponitrous”’ being given to the new acid, there remains the compound term ‘‘hyponitroso-nitrous’’ for the nitric-oxide acid, should this acid ever be obtained. There will thus be the following series of names :— Hy PORItTOUS ACIC. 2.2. Sees HNO Hyponitroso-nitrous acid ........ Ho Ne INTEROUS ACI «oo... cot stwe Bees ee ae HNO, INitroso-mitric;acidy...° 2.08 ater at H, N, O, INGriGiACid Sens ts cr eee ee HNO, - If, however, the terms “‘ hyponitrous”’ and “hyponitric”’ are to be re- tained for the second and fourth members of the above series, the term ‘‘hydro-nitrosylic’? may serve for the new acid, according to its consti-- tution :— Hydrogen. Nitrosyl. H NO I am at present engaged in the further study of this interesting acid and its salts, and hope, before very long, to have the honour to make known the obtained results to the Society. ApDENDvM, April 26, 1871. When the above paper was presented to the Royal Society I was not 1871.] On a New Group of Colloid Bodies. 431 aware that the action of sodium amalgam upon alkali nitrites had been recently investigated by M. Fremy* and M. Maumenéf, neither of whom, however, have anticipated me in the discovery of the new class of salts here described. The latter chemist finds that in one set of circumstances this action gives rise to a body allied in composition and properties to oxyam- monia, and in another only to ammonia. M. Fremy finds that it produces oxyammonia, nitrogen which escapes, and nitrous oxide which remains in solution. So far as I have since been able to experiment, I have found that, by pro- ceeding in different ways, a very small and variable amount of oxyammonia, or a substance resembling it, is often obtained along with the sodium hyponitrite, which is always formed in material quantity ; and, further, that, under the circumstances which favour the formation of oxyammonia, there are also obtained, together with nitrous oxide, the products of the decom- position of oxyammonia by alkalies—nitrogen and ammonia (Lossen). The presence of oxyammonia in the product of the action of sodium on sodium nitrate affords a more satisfactory explanation than that I have given of the darkening of the silver-salt after precipitation which I have sometimes observed to occur. M. Fremy states that alkali nitrites do not decompose potassium per- manganate; and I now find that my assumption to the contrary is an error, based on an observation of considerable interest, which is that some good commercial nitrite im my possession slowly reduces the permanganate. I have since ascertained that other samples of sodium nitrite have no action on the permanganate, and that the one which does react with it behaves also with copper- and lead-salts in such a way as to render very probable the presence in it of a minute quantity of my new salt. This formation of hyponitrite, by heating sodium nitrate, if it does really take place, is in accordance with Hess’s observations of the action of heat on barium nitrate, and with mine on silver nitrite.—K. D. III. “Research on a New Group of Colloid Bodies containing Mercury, and certain Members of the series of Fatty Ketones.” By J. Emerson Reynoxips, Member of the Royal College of Physicians, Edinburgh, Keeper of the Mineral Department, and Analyst to the Royal Dublin Society. Communicated by Rosert H. Scorr, F.R.S. Received January 19, 1871. Introduction.—About ten years ago, when engaged in the examination of some of the constituents of the rectified wood-naphtha of commerce, I observed that moist and freshly precipitated mercuric oxide was dissolved by the naphtha in the presence of potassium hydrate, and that the resulting alkaline solution possessed highly characteristic properties. It was ascer- * Comptes Rendus (1870), vol. Ixx. pp. 66 & 1208. + Ibid. p. 149. 432 Dr. J. E. Reynolds on a New Group of [Apr. 20, tained that the solution of mercuric oxide under the conditions mentioned depended wholly on the presence of aceéone in the crude wood-spirit ; since pure acetone, when treated in the same way with diluted alkali and mercuric oxide, afforded the same result, while the remaining constituents of wood-naphtha failed to produce the reaction. Though obliged at the time to rest content with recording * the obser- vations above referred to, I have since been able to resume the inquiry. As the result, I now venture to lay before the Society the following account of some members of a series of ketone compounds containing mercury, and presenting all the characters of strongly marked codloid bodies, though chemically intermediate between the two groups of colloids previously made known by the researches of the late Professor Graham. Acetone, bemg the most important member of the fatty ketone group, is the body whose compound with mercury I have studied with chief atten- tion, and I may therefore describe in detail the results obtained with it. 1. Colloid body obtained by uniting Acetone with Mercurie Oxide.— When solution of mercuric chloride is slowly added to a mixture of acetone with dilute aqueous solution of potassium hydrate, the mercuric oxide first precipitated is dissolved, with the production of a clear colourless liquid. The addition of the mercurial solution can be continued until a white pre- cipitate makes its appearance, the alkali being still in excess}. If the solution be filtered at this point, an apparently opalescent, yellowish- coloured liquid is obtained{. If one portion of this alkaline solution be boiled for a few minutes, a thick gelatinous mass suddenly separates, and further ebullition is rendered difficult, if not impossible. Another portion of the liquid, when treated with an acid im slight excess, gelatinizes; and if the original solution be moderately strong, the vessel in which the experi- ment is made may be inverted without risk of spilling its contents. Finally, if some of the mercuric solution be exposed over sulphuric acid an vacuo, it leaves on partial evaporation a gelatinous mass, on the surface of which latter crystals of potassium chloride soon make their appearance. When the desiccation is complete, a yellowish resinoid body is obtained, together with a large quantity of very beautiful acicular crystals of the chloride and a certain amount of potassic carbonate. The solution of mercuric oxide in potassium hydrate in presence of acetone takes place as easily in alcoholic as in aqueous liquids. Preliminary experiments similar to the foregoing were sufficient to in- * Journal of the Royal Dublin Society, vol. iv. p. 114. + The same result can be obtained when mercuric oxide is precipitated from any of its salts, rapidly washed, and then digested with excess of acetone and potassium hydrate. The best mode of operating, however, is that stated in the text. { The different solutions exhibit a slight opalescence, not completely removable by ordinary filtration. This opalescence appears to be due to the very gradual separation, at ordinary temperatures, of traces of the same anhydrous substance which is very _rapidly thrown down at a boiling heat. In composition the latter body is identical with the anhydride obtained by other methods and described further on. 1871.] Mercurial Colloids and certain Fatty Ketones. 433 dicate that the chief compound produced in the reaction above referred to might be regarded as a colloid body. I therefore took advantage of the late Professor Graham’s beautiful dialytic method * for effecting its puri- fication from crystalloids, and have met with complete success. a. Preparation of Colloid Liquid.—As the preparation of a strong solution of the pure acetone mercuric compound suitable for dialysis is attended with some difficulty, I may now describe in detail the mode of operating proved by experience to afford the most satisfactory results. Forty grammes of pure mercuric chloride are to be dissolved in about 500 cub. centims. of hot water and the solution then allowed to cool, even though crystals of the salt separate. Twenty-nine grammes of potassium hydrate are next dissolved in about 300 cub. centims. of water: 15-20 cub. centims. of acetone should now be placed in a capacious glass balloon, and diluted with 250 cub. centims. of water. The reaction is then to be managed as follows :—About 150 cub. centims. of the alkaline solution should be added to the aqueous acetone, and then 250 cub. centims. of the mercuric chloride gradually poured in. Re-solution of the mercuric oxide first thrown down proceeds slowly at the outset, if the mixture be not warmed. After a time the oxide quickly redissolves, if the contents of the balloon are briskly agitated. When the first half of the mercuric solution has been added, the remaining 150 cub. centims. of potassium hydrate are to be cautiously poured in and the residual mercuric chloride then mixed, with the precautions already stated. The solution prepared in the manner described is usually turbid, but can be easily filtered clear from the small amount of mechanically sus- pended matter. The filtrate should next be placed on a large hoop dialyzer, covered as usual with carefully prepared parchment-paper, and the vessel floated on a considerable volume of distilled water. After two days’ action the diffusate will be found to contain a large quantity of potas- sium chloride, some potassium hydrate, and but a very small amount of mercury. The process of diffusion is to be continued, the diffusate being replaced by pure water twice each day, until the liquid on which the dialyzer floats no longer affords a cloud when treated with a solution of silver nitrate. The process may then be considered terminated, and the pure colloidal liquid obtained. The contents of the dialyzer can be now removed, and should be free from ali odour of acetone. A few drops, when evaporated to dryness on platinum-foil and the residue ignited, should volatilize completely. The mode of operating just described affords the strongest colloidal liquid that can be conveniently prepared directly in a pure state; but where degree of concentration is of no importance, I find that it is better to dilute the alkaline mercurial solution with its own volume of pure water just before dialyzing. The properties of the colloidal liquid will be described most conveniently * « Viquid Diffusion applied to Analysis,” Philosophical Transactions, 1861. 43.4: Dr. J. E. Reynolds on a New Group of [Apr. 20, after the results of the analyses of the anhydrous mercuric compound se- parable from it in the pure condition shall have been stated. b.-Analyses of the Anhydrous Compound.—I took a considerable volume of the very carefully prepared colloid liquid and divided it in two parts. One portion was very cautiously evaporated to dryness, and the resinoid residue very finely powdered and carefully dried. The second portion was precipitated by the addition of dilute acetic acid, and the gelatinous pre- cipitate washed rapidly and completely with the aid of Bunsen’s filter- pump, and the residue dried. The desiccation in each case was effected at first in vacuo over sulphuric acid, and finally on the water-bath. The compound easily bears a temperature of 100° C. - On analyzing both products, I found that they were practically identical in composition. The residue of the evaporation of the colloid liquid con- tained, as might be anticipated, a slightly greater proportion of mercury than the precipitate by dilute acid. The circumstances under which the precipitate was produced, however, were such as to give most confidence in the purity of the product; I have therefore employed this latter or similar preparations in many of the determinations, the results of which will be presently stated. The compound was found to contain carbon, hydrogen, mercury, and oxygen, and to be free from chlorine. As the presence of the volatile metal introduced some difficulty in the determinations, it is necessary to describe the plan of analysis adopted. The mercury was in some cases obtained in the metallic state by dis- tillation with quicklime; but I much prefer to digest a weighed quantity of the compound in a sealed tube with dilute hydrochloric acid, and, after complete solution has taken place, to break the tube, precipitate the metal from the contents by sulphuretted hydrogen, and weigh the mercury in the usual way as sulphide. The results are very satisfactory. The presence of a large proportion of mercury in the compound rendered the accurate determination of carbon and hydrogen somewhat difficult. At the outset of this investigation I arranged a very troublesome process of analysis, similar to that employed by Messrs. Frankland and Duppa in their analysis of mercuric ethide and its analogues. In all later combustions I have adopted the very simple and satisfactory plan of placing in the anterior part of the combustion-tube a layer of fifteen cen- timetres of any metal capable of easily amalgamating with mercury. Gold- and silver-foil answer the purpose well : no doubt tin-foil might be used in the same way. It is scarcely necessary to add that the tempera- ture of the anterior part of the combustion-tube containing the gold or silver was in each instance very carefully regulated. The following results were obtained :— I. :997 grm. of substance gave *9037 grm. of Hg 8. II. °8618 grm. of substance gave ‘3077 grm. of CO, and ‘1158 grm. of H;-O: 1871.] Mercurial Colloids and certain Fatty Ketones. 435 III. :4940 grm. of another preparation gave ‘4485 grm. of Hg S. IV. -6640 grm. afforded :2344 grm. of CO, and 0870 grm. of H, O. V. 1:2148 grm. of residue of evaporation of colloid liquid gave 9°562 grm. of Hg. VI. °8156 grm. of another preparation gave °6425 grm. of Hg. Experiment. Calculated. Aa aA a —osN Ik 1 is LEE: IV. V. VI. WaCHON; 5.5.05 72 9:43 Se OGY | ee 9°62 Hydrogen ...... hao lei 7, ee Tea Ore a PApe Se es a Mercury..:...... GU0S (S:a05 STS1O Fos IS 26 ca FO fous e OXVPEN ~....00. 80 10:47 oe sis oe be oe Sos 764 100-00 The composition of the body is therefore well represented by the formula ((CH,), CO), Hg, O,. c. Properties of the Colloid Body, Hydrated and Anhydrous.—Ana- logy would lead us to conclude that the colloidal liquid obtained by dialysis is a hydrate of the body represented by the above formula; but since evaporation tm vacuo is sufficient to remove the water completely, the hydrate can possess but little stability. Properly speaking, this hydrate is no doubt a true liquid, and as such is miscible with other liquids. The reaction of this hydrate is neutral to test-papers. When the aceto-mercuric hydrate contains five per cent. of the anhy- drous compound, it will, if quite pure, remain liquid for twelve or fourteen days, toward the end of this time becoming gradually less fluid, until the whole ‘sets’? to a firm jelly. The same result may be brought about in a few seconds by the addition to the perfectly neutral liquid of very minute quantities of any of the following substances :—Hydrochloric, acetic, nitric, sulphuric (incompletely), chromic, oxalic, tartaric, or citric acids; by potassium, sodium, ammonium, barium, and calcium hydrates ; by calcium chloride, mercuric chloride, sodium acetate, and other neutral salts. Contact with certain insoluble powders, such as calcium carbo- nate, and even alumina, induces pectization*. Elevation of temperature quickly determines the gelatination of the liquid. If containing five per cent. of the ketone compound, a very firm jelly is produced on heating to 50° C. In one experiment, a quantity of the liquid was taken and some bright, carefully cleaned copper-gauze introduced. The liquid did not pectize, nor did any trace of mercury deposit on the copper, after standing fora day. The temperature of the whole was then raised to 50° C.; a transparent jelly was at once produced, of such strength that the vessel in which it was contained could * In accordance with the nomenclature of Prof. Graham, we must call the liquid colloid hydrate the “hydrosol” of the new compound, the gelatinous hydrate the “hydrogel,” and the change from the former to the latter “‘ pectization.” 436 Dr. J. E. Reynolds on a New Group of [ Apr. 20, be inverted without any risk of loss. This jelly, closing the bright copper-gauze, has remained in my possession for eight months without giving the slightest indications of a disposition to change. Small zoological specimens, when inclosed in the same way in a jelly of the mercuric ketone compound, were found to keep well when carefully cleansed before they were sealed up in the gelatinous envelope. By evaporation, a liquid containing eight per cent. of the ketone com- pound was obtained, but it pectized in a few jhours. A two per cent. hydrate retained its liquidity for several months. Once a jelly formed in any of these liquids, I have not succeeded completely in reconverting it to the liquid state by very cautious treatment with potassium hydrate, even when aided by diffusion. The alcosol of the mercuric ketone compound was obtained by the method adopted by Prof. Graham in preparing the corresponding silicic alcoholate, —that is to say, by adding to a one per cent. hydrate an equal volume of alcohol, and exposing the mixture over quickliime until most of the water was removed: the alcosol remained. This liquid could be boiled without pectizing; but if the ebullition continued for some time, a jelly was suddenly obtained. This insoluble jelly corresponded to that produced on heating the hydrate, or adding to it any of the bodies capa- ble of pectizing it; in the former case alcohol, and in the latter water, being associated or united with the mercuric ketone compound. It has now been shown that the new body is capable of affording a hydrosol and hydrogel, an alcosol and alcogel; it must therefore be regarded as a very strongly marked member of Prof. Graham’s group of these colloids, though chemically differmg widely from previously de- scribed compounds of this class. When the colloid hydrate was treated with sulphuretted hydrogen, mercuric sulphide was produced. The liquid filtered from the sulphide yielded acetone on distillation. Digestion with dilute hydrochioric acid likewise effected the decomposition of the colloid body, mercuric chloride being produced and acetone liberated. Nitric and sulphuric acids, when dilute, did not decompose the compound with the same facility as hydro- chloric acid. ‘Treatment of the hydrosol with copper, zinc, or iron aé or- dinary temperatures, failed to effect the substitution of either metal for the mercury in the compound. Prolonged contact with each of the two last- mentioned metals caused pectization, the metal subsequently becoming encrusted with a white substance. Heat produced the same result more rapidly. When the anhydrous compound was cautiously heated, a quantity of acetone distilled over, and, as the temperature rose, empyreumatiec pro- ducts and mercury were evolved. When the heat was suddenly applied, much metallic mercury distilled over, and a minute quantity of a liquid, having the odour of mercuric methide, was produced, together with car- bonic anhydride and other gaseous bodies not particularly examined. If 1871.) Mercurial Colloids and certain Fatty Ketones. 4.37 mercuric methide be formed during the rapid decomposition of the mer- curie compound, the first step m the reaction by which it is produced may be explained by the following equation :— [200(CH,),, 3Hg0]=2 GH | Hg )+Hg+200,+0. The mercuric methide produced in the first instance, probably at another stage suffers nearly complete decomposition in presence of the oxygen liberated at the outset of the reaction. d. Chemical nature of the Diaceto-mercuric Hydrate.—In the pre- ceding section the properties of the colloid liquid and other bodies ob- tained by dialysis from the potass solution have been described; but the potassium hydrate used in the first instance may be replaced by solution of sodium, barium, or even calcium hydrate, and yet the same ultimate result arrived at. When sodium hydrate is employed, no material dif- ference is observed at any stage of the operations, but when barium hydrate is substituted, re-solution of mercuric oxide m presence of acetone is quickly effected with the aid of heat ; but this alkaline solution slowly decomposes, yieldimg a white precipitate of the mercuric ketone com- pound, mixed with a little barium carbonate. This decomposition takes place in closed vessels, and most rapidly when the solution has been boiled in course of preparation, and when no excess of barium hydrate has been employed beyond the amount absolutely required to secure the retention of the mercuric compound im solution. Keeping in view the peculiar mode of generation of the mercuric ketone compound, its solubility in alkaline liquids at the time of its forma- tion, and insolubility without decomposition in acid solutions, its power of uniting with water to form both liquid and gelatinous hydrates, and the extremely close analogy of these in properties and relations to the ‘ co- silicic acids”? of Prof. Graham, we are compelled to attribute to the new hydrates very feeble acid functions. _ The alkaline solutions above referred to may therefore be regarded as containing metallic salts of a peculiar acid, derived from the compound ((CH,),CO),Hg.0,, already described. That these salts are, however, even more easily decomposed than alkaline silicates is shown :— Ist. By the easy decomposition of the potassium salt by the process of liquid diffusion. The osmotic force alone is sufficient for this purpose, the high diffusive energy of potassium hydrate enabling it to rapidly pass through the dialytic septum, leaving behind the colloid acid in the liquid state. The analogous decomposition occurs somewhat less readily in the case of potassium silicate. 2nd. By the facility with which the new acid may be displaced from the aqueous solutions of its potassium, sodium, or barium salts by so feeble an agent as carbonic acid. Solutions of alkaline silicates are well known to decompose in the same manner, but less rapidly. 438 _ Dr. J. HE. Reynolds on a New Group of [Apr. 20, 8rd. By the fact that heat alone is able to effect the decomposition of the potassium salt, a solution of the latter giving a yellowish-white precipi- tate of the anhydrous mercuric ketone compound on violent ebullition, the alkali remaining dissolved*. Re-solution does not take place on cool- ing, or on digestion with an excess of the metallic hydrate at the ordinary temperature. It is, however, worthy of note here that the gelatinous precipitate produced by acetic acid in a solution of the potassium salt is soluble in excess of potassium hydrate immediately after.its formation ; but it soon loses this property and alters somewhat in appearance, becoming more dense. With a view to obtain, if possible, some evidence of the basicity of the acid, a quantity of mercuric chloride was dissolved in water, the theore- tical proportion of pure acetone added, and excess of potassium hydrate. Complete re-solution of the mercuric oxide was obtained’as usual. To the alkaline liquid dilute hydrochloric acid was added, until a moderate quantity of the white mercuric-acetone compound had been precipitated. The whole was then filtered as clear as possible. The filtrate now contained, in addition to potassium chloride resulting from the reaction, a certain amount of the mercuric-acetone compound, held in solution by a minimum of alkali. In order to determine the ratio between the anhydride or acid and potassium present in combination, 100 cub. centims. of this solution were now taken, treated with excess of hydrochloric acid, and the mercury precipitated as sulphide by means of sulphuretted hydrogen. The pure mercuric sulphide obtained in this manner weighed 1°056 gramme: this amount represents 1:1591 gramme of the anhydrous mercuric-acetone compound, as calculated from the formula already found for that body. Another 100 cub. centims. of the same solution were taken, and dilute sulphuric acid of known strength very.cautiously added, until a drop of the liquid faintly reddened blue litmus-paper: 5°4 cub. centims. of acid were required; this amount of acid represented ‘2106 gramme of potas- sium. 100 cub. centims. of the solution, completely free from eacess of alkali, therefore contained of erm (CO(CH,),),Hg,0,..... ves sisoe ee 11591 Aloe one ba pee 2106 These numbers, when divided in the usual way by the respective atomic weights, gave the proportion of 1: 3°6. The foregoing experiment is but one of many performed with a similar result, the main ratio found for different solutions being 1:3°7. When the conditions under which the determinations were made are considered, the ratio 1:4 may be admitted as the true result. * Tn this, as in many other respects, a strong solution closely resembles in deport- ment a liquid containing white of egg. 1871.] Mercurial Colloids and certain Fatty Ketones. 439 A solution of the barium salt was now prepared with great care, the presence of excess of barium hydrate being guarded against by very cau- tious manipulation in the first instance, and subsequent treatment with acetone and mercuric chloride, until the liquid ceased to dissolve more mercuric oxide. The acid treatment resorted to in the case of the potassium salt was found to be unsuitable in the present instance: 100 cub. centims. of the clear filtered liquid were taken, immediately after preparation of the solution, and treated with excess of hydrochloric acid until complete de- composition was effected ; the mercury was then precipitated as sulphide : *5062 gramme was obfained; this amount represents °5555 gramme of the anhydrous mercuric-acetone compound. 100 cub. centims. were treated with a standard acid: 3°3 cub. centims. were required before an acid reaction was developed; this corresponds to ‘2244 gramme of barium. 3 We therefore find in 100 cub. centims. of the solution of BROCE VEO ict ctasliy wacdete MS ‘5555 Bal! Toe When these numbers are treated as before, we find that the ratio of anhydrous ketone compound to barium is 1:1°84. As in the case of the potassium salt, the chances of error are altogether in the direction of under-estimating the barium and over-estimating the remaining consti- tuent of the salt; the ratio 1:2 may therefore fairly be taken as the practical result of these determinations. Potassium being monovalent and barium divalent, it would appear that the solutions above mentioned contained respectively the normal potas- sium and barium salts of an extremely feeble but yet distinctly marked tetrabasic acid. When any one of these liquids was evaporated to dryness 7 vacuo over sulphuric acid, a resinoid mass was in each case obtained, from which metallic chloride was removable by water; but since partial decomposition appeared to. take place during the process of evaporation in each case, the now insoluble resinoid body, containing potassium, so- dium, or barium, could not be regarded asa pure salt ; nor have I suc- ceeded in obtaining any other solid compound of this acid in a condition suitable for oaage When to a liquid containing the potassium salt of the acid a solution of potassium hydrate, eee with zinc hydrate, was added, a semi- transparent gelatinous precipitate was obtained. On washing with water this substance quickly became basic. Other attempts with various metals did not afford better results, precipitates of variable composition being obtained in each case. It would appear, then, that only the most powerful soluble metallic hydrates are capable of forcing the new acid to remain in combination, and that even these alkaline salts are so feebly held together, that decomposition attends the attempt to obtain them in the solid state. VOL XIX. 2M 440 Dr. J. E. Reynolds on a New Group of [Apr. 20, If we admit the existence of these salts in the solutions examined, they might be named di-aceto-mercurates, or probably di-keto- mercinates, the. latter name being used as a general term. e. Detection of Acetone in the “« Methylated Spirit’? of Consol — Since acetone is, according to my experience, invariably present in the wood- spirit of commerce, the reaction with mercuric oxide in presence of potas- sium hydrate, already described, becomes virtually a test for the presence ‘of pyroxilic spirit in any mixture. The ordinary “ methylated spirit” of commerce is such a mixture, and the acetone present in it can be detected with great facility in the following way :—Take 200 cub. centims. of the. spirit and rapidly distil off 50 cub. centims.; dilute the distillate with an equal volume of water, and slightly warm with addition of a few cub. centims. of solution of potassium hydrate. On cautious addition of mercuric chloride, the oxide first thrown down is speedily redissolved : excess of the mercuric salt must be carefully avoided. The alkaline liquid should be filtered clear, much of the alcohol allowed to evaporate slowly, and the residue then di- vided in two portions. ‘ One'part is to be’violently boiled for a few minutes ; a yellowish-white gelatinous precipitate will suddenly make its appearance, if the acetone compound be present. In the second portion, dilute acetic acid, when added in slight excess, should produce a bulky, white, gela- tinous precipitate containing, when washed and completely dried, between 78 and 79 per cent. of mercury. Finally, by means of the above test the admixture of ‘‘ methylated spirit”? with alcoholic solutions may be detected with facility. In all such cases, however, a specimen of a pure alcoholic solution should be tested at the same time as the suspected sample, distillation of considerable quantities of the liquids being resorted to in every instance. 2. Bodies containing Mercury and higher members of the Fatty Ketone sertes.—Experience has proved that several ketones of the fatty series are capable of uniting with mercuric oxide in the presence of alkali to form compounds analogous to that obtained with acetone. The higher ketones. being insoluble in water though soluble in alcohol, it was found to be ex- tremely difficult to prepare the colloidal hydrates or hydrosols of the mer- curie compound. In the case of butyrone, however, I have succeeded oes in ob- taining a hydrosol. The general reactions of the several solutions leave no doubt that the compound contained in each belongs to the group of colloid bodies and not to that of crystalloids. The following results have been obtained :— (a) With Propione.—The rectified product of the careful destructive distillation of barium propionate was dissolved in alcohol and mercuric chloride added ; excess of strong aqueous solution of potassium hydrate was then poured in; on gently warming the mixture the mercuric oxide dissolved in great part. The liquid, filtered as clear as possible, was found 1871.] | Mercurial Colloids and certain Fatty Ketones. AAT to be rich in mercury, and when treated with excess of dilute acetic acid, gave a white gelatinous precipitate precisely analogous to that obtained under similar circumstances from the potassium di-aceto-mercurate. The precipitate was found on analysis to contain 72:26 per cent. of mer- eury; the formula requires 73°17 per cent. On treatment with hydro- chloric acid, the precipitate afforded mercuric chloride and an oily liquid, insoluble in water, possessing the odour of and characters attributed to propione. (b) With Butyrone.—The rectified product of the destructive distilla- tion of calcium butyrate, when dissolved in alcohol and treated with mer- euric chloride and potassium hydrate, gave, on warming, a liquid similar to that obtained with propione. Like the latter, it afforded a white pre- cipitate on treatment with excess of dilute acetic acid. The precipitate, when carefully washed and dried, contained 69°1 and 69°27 per cent. of mercury, the formula ((C,H,),CO)Hg,0, requiring 68°49 per cent. The freshly prepared precipitate, when digested with excess of hydrochloric acid, afforded mercuric chloride and a small quantity of a liquid insoluble in water and recognizable as butyrone. The alkaline alcoholic solution of the butyrone mercuric compound was diluted with its own volume of water, then filtered and carefully warmed in order to slowly evaporate the alcohol as much as possible. Whena considerable portion of the latter had been removed in this way, the clear residual liquid was placed on a dialyzer, and the attempt made to diffuse away the crystalloids from the liquid. After treatment for five days, most of the chloride had diffused away, and a liquid was obtained which pec- tized on heating to near the boiling-point and on the addition of a small quantity of a mineral acid. The precipitate first formed by hydrochloric acid was easily redissolved on heating with excess of the reagent, and the odour of the ketone developed. The attempt to convert the alcosol of the mercuric compound into the ee had EL oe been attended with, SUCCESS. (c) With Valerone, abiaanted by paceine the product of i distillation of calcium valerate previously mixed with one-sixth of its weight of quick- lime. When this was dissolved in alcohol and the solution was rendered alkaline by potassium hydrate and mercuric chloride dropped in, the mer- curic oxide first precipitated was speedily redissolved ; but from the solution no precipitate was thrown down on addition of an acid previously mixed, with alcohol. I have not obtained any compound from this alkaline liquid possessing distinctive properties. It is not improbable that the valerone mercuric compound, if formed, is more easily decomposed by acids than the corresponding bodies obtained with other ketones; hence the difficulty of isolating it. 3. Deportment of certain Aldehydes in presence of Mercurie Oxide and Alkaline Metalic Hydrate.—The close similarity in che mical relations be- 2M 2 AAL2 On a New Group of Mercurial Colloids &c. (Apr. 20, tween the members of the groups of ketones and of aldehydes suggested the attempt to combine the latter bodies with mercuric oxide. Though the experiments in this direction cannot properly be detailed in this communi- cation, I may be permitted to state that when the aldehyde of the ethyl series was warmed with freshly precipitated mercuric oxide in presence of potassium hydrate, solution of the oxide did not take place, but the latter gradually united with the aldehyde to form a white non-crystalline com- pound. I have not obtained any colloid liquid in the course of my experi- ments with this body. Certain other aldehydes of the same series were found to unite with mercuric oxide, yielding soluble compounds easily decomposed by weak acids. The investigation of the bodies produced in these reactions has been attended with peculiar difficulty, owing, on the one hand, to the facility with which several aldehydes are converted into resinoid products of va- riable composition by contact with caustic alkali; and, on the other, to the circumstance that an aldehyde can react either as the oxide of a di- valent group (C,Hoe,'O), or as the hydride of a monovalent acid radical (C,Hen-10, H, or, for terms of the series above methylic aldehyde, we may write the formula CO(C,,H2,_1) H). It may be added, that the well- known tendency of the aldehyde to yieid polymeric compounds has in no degree lessened the uncertainty attending the examination of the products of the action of mercuric oxide and alkali upon the members of the group. Leaving the statements contained in the last section out of consideration for obvious reasons, I may now be allowed to summarize the results of the investigation detailed in the foregoing pages. It has been shown :— Ist. That certain fatty ketones can be made to unite directly with mer- curic oxide. 2nd. That the resulting compounds afford a new group of colloid hy- drates, analogous in properties to the silicic, alouminic, and other hydrates already made known by the researches of Professor Graham. 3rd. That the new hydrates may best be regarded as extremely feeble conjugate acids, the chief member of the group (that derivable from acetone) being probably tetrabasic and capable of affording very unstable salts. Ath. That the generating reaction for the idlaston mercurates may, when carefully controlled, be employed as a test for the presence of a ketone (especially for acetone) in certain organic mixtures. 1871.] Dr. C. W. Siemens on Electrical Resistance, 443 April 27, 1871, Gencral Sir EDWARD SABINHE, K.C.B., President, in the Chair. Tue Baxertan Lecture was delivered by Cuartes WILLIAM Siemens, F.R.S., D.C.L., “ On the Increase of Electrical Re- sistance in Conductors with rise of Temperature, and its appli- cation to the Measure of Ordinary and Furnace Temperatures ; also on a simple Method of measuring Electrical Resistances,” The following is an Abstract. The first part of this Paper treats of the question of the ratio of increase of resistance in metallic conductors with increase of temperature. The investigations of Arndtson, Dr. Werner Siemens, and Dr. Matthies- sen are limited to the range of temperatures between the freezing- and boiling-points of water, and do not comprise platinum, which is the most valuable metal for constructing pyrometric instruments. Several series of observations are given on different metals, including platinum, copper, and iron, ranging from the freezing-point to 350° Cent. ; another set of experiments being also given, extending the observations to 1000° Cent. These results are planned on a diagram, showing a ratio of increase which does not agree either with the former assumption of a uni- form progression, or with Dr. Matthiessen’s formula, except between the narrow limits of his actual observations, but which conforms itself to a parabolic ratio, modified by two other coefficients, representing linear ex- pansion and an ultimate minimum resistance. In assuming a dynamical law, according to which the electrical resistance of a conductor increases according to the velocity with which the atoms are moved by heat, a parabolic ratio of increase %f resistance with increase of temperature follows ; and in adding to this the coefficients just mentioned, the resistance 7 for any temperature is expressed by the general formula ~ r=aT?#+6T+y, which is found to agree very closely both with the experimental data at low temperatures supplied by Dr. Matthiessen, and with the author’s ex- perimental results, ranging up to 1000° Cent. He admits, however, that further researches will be necessary to prove the limits of the applicability of the law of increase expressed by this formula to conductors generally, especially when nearing their fusing-point. In the second part of this Paper it is shown that, in taking advantage of the circumstance that the electrical resistance of a metallic conductor in- creases with an increase of temperature, an instrument may be devised for measuring with great accuracy the temperature at distant or inaccessible places, including the interior of furnaces, where metallurgical or other smelting-operations are carried on. 444, Dr. C. W. Siemens on Electrical Resistance. [Apr. 27, In measuring temperatures not exceeding 100° Cent., the instrument is so arranged that two similar coils are connected by a light cable containing three insulated wires. One of these coils, ‘‘ the thermometer-coil,” being carefully protected against moisture, may be lowered into the sea, or buried in the ground, or fixed at any elevated or inaccessible place whose tempe- rature has to be recorded from time to time; while the other, or ‘‘ com- parison-coil,’’ is plunged into a test-bath, whose temperature is raised or lowered by the addition of hot or cold water, or of refrigerated solutions, until an electrical balance is established between the resistances of the two coils, as indicated by a galvanoscope, or by a differential voltameter, de- scribed in the third part of the paper, which balance implies an identity of temperature at the two coils. The temperature of the test-solution is thereupon measured by means of a delicate mercury thermometer, which at the same time tells the temperature at the distant place. _ By another arrangement the comparison-coil is dispensed with, and the resistance of the thermometer-coil, which is a known quantity at zero tem- parature, is measured by a differential voltameter, which forms the subject of the third part of the paper; and the temperature corresponding to the indications of the instrument is found in a table, prepared for this pur- pose, in order to save all calculation. In measuring furnace temperatures the platinum-wire constituting the pyrometer is wound upon a small cylinder of porcelain contained in a closed tube of iron or platinum, which is exposed to the heat to be mea- sured. If the heat does not exceed a full red heat, or, say, 1000° Cent., the protected wire may be left permanently in the stove or furnace whose temperature has to be recorded from time to time ; but in measuring tem- peratures exceeding 1000° Cent., the tube is only exposed during a mea- sured interval of, say, three minutes, to the heat, which time suffices for the thin protecting casing and the wire immediately exposed to its heated sides to acquire within a determinable limit the temperature to be measured, but is not sufficient to soften the porcelain cylinder upon which the wire is wound. In this way temperatures exceeding the welding-point of iron, and approaching the melting-point of platinum, can be measured by the game instrument by which slight variations at ordinary. temperatures are told. A thermometric scale is thus obtained embracing without a break the entire range. The leading wires between the thermometric coil and the measuring in- strument (which may be, under certain circumstances, several miles in length) would exercise a considerable disturbing influence if this were. not elimi- nated by means of the third leading wire before mentioned, which is common to both branches of the measuring instrument. Another source of error in the electrical pyrometer would arise through the porcelain cylinder upon which the wire is wound becoming conductive at very elevated temperatures ; but it is shown that the error arising through this source is not of serious import. 1871.] M. Berthelot on Chemical Combination. 445 The third part of the paper is descriptive of an instrument for measuring electrical resistance without the aid of a magnetic needle or of resistance scales. It consists of two voltameter tubes fixed upon graduated scales, which are so connected that the current of a battery is divided between them, with one branch including a known and permanent resistance, and the other the unknown resistance to be measured. ‘The resistance and pola- rization being equal, and the battery being common to both circuits, these unstable elements are eliminated by balancing them from the circulation ; and an expression is found for the unknown resistance X in terms of the known resistances C and y of the voltameter, including the connecting- wires, and of the volumes V and V’ of gases evolved in an arbitrary space of time within the tubes, viz. :— X=—,(C+y)- Visa ova wiakiepeeaeeh) Changes of atmospheric pressure affect both sides equally, and do not therefore influence the results ; but a reading at the atmospheric pressure is obtained at both sides by lowering the little supply-reservoir with dilute acid to the level indicated in the corresponding tube. The upper ends of the voltameter tubes are closed by small weighted levers provided with cushions of India-rubber ; but after each observation these levers are raised, and the supply-reservoirs moved so as to cause the escape of the gases until the liquid within the tubes is again brought up to the zero-line of the scale, when the instrument is ready for another observation. A series of mea- surements are given of resistances varying from | to 10,000 units, showing that the results agree within one-half per cent. with the independent measurements obtained of the same resistances by the Wheatstone method. The advantages claimed for the proposed instrument are, that it is not influenced by magnetic disturbances or the ship’s motion if used at sea, that it can be used by persons not familiar with electrical testing, and that it is of very simple construction. The following communications were read :— I. “On the Change of Pressure and Voluine produced by Giunta] Combination.” By M..Brrtnetor. Communicated by Dr. Wiiramson. Received April 25, 1871. 1. A singular question has arisen in the study of the gaseous com- binations, viz. can the pressure be diminished in consequence of a reac- tion, at the moment it is accomplished, at constant volume, without loss of heat, so that the phenomenon of explosion comes from the excess of atmospheric pressure upon the inner pressure of the system, instead of coming from the inverse excess of the inner pressure? The discussion of this question, however special it appears at first sight, leads to general notions concerning chemical combination. 446 M. Berthelot on the Change of Pressure and Volume [Apr. 27, 2. The pressure depends upon the temperature evolved, and upon the state of condensation of the products. Let us determine this quantity. _ Let ¢ be the temperature produced by the real reaction, this being effected at a constant volume, admitting that the whole of the disengaged heat was employed in warming the products. Let V be the sum of the volumes of the gaseous bodies in the initial system at 0° and 0™ 760. At the Lenaperauune ¢, the final ayetens contains in general certain gaseous bodies. Let V’ be the volume of these Lae supposed to be brought, without changing their state, to 0° and 0™*7 ! The relation = K CxPresses the condensation produced by the reaction. When certain bodies, contained in the initial system at 0°, or in the final system at ¢°, are in the solid or the liquid state, you can generally neglect their volume in comparison with that of the gas, when the pressures are not too considerable. Let us calculate the pressure during the reaction which takes place at a constant volume and at the temperature ¢, the initial temperature and pressure being 0° and H. In admitting Marriotte’s and Gay-Lussac’s laws, the pressure will become Hx 2(1+ad); it will be greater than the initial pressure if 1 + a¢>K, less if 1+aé * 7-200 9M 501 * 502. a3 ee we have very strong evidence that the value of jog 2 is inaccurate, and that () is the correction to be applied to it. By subtracting (C) from (A), we obtain (C)—(A)=... (9ciphers)...1 11064 84985 30114 97702 62179 26049 23519 SBO7B gg ln ee & The difference of the corresponding series (omitting as before the terms involving the Bernoulli’s numbers) NO ae 1d Ponies S00 mee ee - Having only this one* difference-result involving log 5, it is impossible to decide from (A), (B), (C), and (D) whether the harmonic series or log 5 or both are in error ; but the following reasoning places it beyond all doubt that (F) is a correction to log 5, and that the sum of the harmonic series is correct. 1 1 501 + 202 1 ; : + 500 of the harmonic series, as well as log 5, would be common to both.—June 16, * By subtracting (B) from (D) we might get another, but the portion 1871.] Calculation of Euler’s Constant. 521 Mr. Shanks computed log 2 and log 5 from formule. of the form Log 2=2 (7 P+5 Q+3 R), Log 5=2 (16 P+12 Q+7 R), P, Q, and R being infinite series (Proc. Roy. Soc. vol. vi. p. 397; ‘ Rectifica- tion of the Circle,’ p. 88). If, therefore, any error was made in the calculation of P say, it would produce errors in log 2 and log 5 proportional to 7 and 16. On trial it was found that sixteen times (E) was equal to seven times (F*’), the difference being only such as an error of a unit in the 100th decimal of (E) or (I") would produce. This afforded a moral proof that Mr. Shanks had made an error equal to one-fourteenth of (E) in the calculation of P, or BP Soe ee 31'°3.3P'5.3P T°": which has rendered his values of log 2 and log 5 incorrect, and that (with the exception of the error previously noticed) the harmonic series was summed correctly. Since log 3 was calculated from the formula Log 3=2 (11 P+8 Q+5 R), its value is also incorrect, as also is that of log 10 (log 2+ log 5) and the modulus (the reciprocal of log 10). The values of all these quantities are given to 205 decimal places in vol. vi. Proceedings of the Royal Society, p. 397; but all the figures after the 59th decimal place are incorrect in each case. The correct values to 100 places are :— Log 2=:69314 71805 59945 30941 72321 21458 17656 80755 00134 36025 52541 20680 00949 33956 21969 69471 56058 63326 89641 86875... Log 3=1:09861 22886 68109 69159 52452 36922 5257 AG474 90557 82274. 94517 54694 39363 74942 93218 60896 68736 15754 81373 20888 . . Log 5=1:60948 79124 34100 37460 07593 35226 18763 95256 01354 26851 7219 12647 89147 ALTED 87707 65776 46301 38878 09517 VOLO Sra. « Log 10=2:30258 50929 94045 68401 79914 54684 36420 76011 01488 62877 29760 33927 90096 79726 09677 30248 023 Or ide) 97205 0&959 82982 . It is to be observed that the above value of log 3 is not quite as well determined as the others; the calculations in regard to Euler’s constant 522 Mr. J. W. L. Glaisher on the [June 15, form a real verification of log 2, log 5, and log 10; they also verify P, Q, and R; but an error in log 3 in the transcription of P, Q, and R, or their multiplication by 11, 8, and 5, or in the final addition and multipli- cation by 2, would not be detected. In the above logarithms the last figure may be in error to the extent of one or two units. The value of Euler’s constant to 100 decimal places is— y= 57721 56649 01532 86060 65120 90082 40245 10421 59335 93992 30988 05767 23488 A8677 26777 66467 09369 47063 29174 67497... The last figure here also may be in error to the extent of one or two units. It will be observed that Mr. Shanks’s value* of y for 2=500 differs from (C) in the 65th decimal place, and that his value for z=1000 differs from (D) in the 78rd place. This is caused by an inaccurate value of B,, . 8553103 haying been made use of. The correct value of B,, is —— ; but Euler, : 60 53103 who first calculated it, made it —S—( Acta Petropolitana’ for 1781, p- 46), and this incorrect value is given in the ‘Penny Cyclopeedia’ (Article «« Numbers of Bernoulli’’) and probably in other places. The values of the first thirty-one Bernoulli’s numbers are given in a paper by Ohm (Crelle’s Journal, t. xx. p. 11), and B,, is given correctly there. The agreement of the values of Euler’s constant contained in this paper (when the logarithms of 2 and 5 are corrected) afford a complete verification of the Bernoulli's numbers as far as B,,, and partial verifica- tions of the rest. The difficulty and inconvenience of making calculations to so many de- cimal places is sufficient to warrant the publication of the values of the positive and negative parts of the portion of the series involving the Ber- noulli’s numbers, in case any one shonld desire to repeat any part of the calculation. We have 5, Bee 1 1 1 = SS =| er ee _ 2— ——-! —— an 6e0g ht ce te 8 © or ape oo eee ; and if m denote the sum of the terms of the same sign as the harmonic series, and 2 the sum of the terms of the same sign as the logarithms, viz. if mn 9 7 get 10217 Pe Bb, — é Bro. \ Ag! Speed a mae * Proc. Roy. Soc. vol. xv. p. 482. reach} Calculation of Euler’s Constant. 523 then, when 7=100 :— m='00000 — 83333 33907. 80158 alle 44885 67821 ala2l 67823 08773 00082 30639 33/61 49846 36254 14224 82920 15089 52013 00966 O89 2 as n=00500 00000 83333 33375 00000 21092 80052 53967 776386 659871 91105 s(« 84750 ~=—s« 27388. —s‘iéi«k912—Sé«‘<‘éw A 39311 34887 * 61884 ..97280 . 71640 Ieee. When r=200::— m=‘00000 20833 38333 39583 78016 61283 59538 59711 91078 12258 99800 92187 99399 17052 51095 93490 89894 78957 35141 06774 O14. n= ‘00250 00000 05208 33339 49609 37505 14960 84887 28877 09510 05685 64006 82170 i770 13023 01074 39246 38458 79084 75675 042... When «=800:— m= ‘00000 03333 30033 33358 73015 87309 34487 73462 49678 ZLTAg 87864 83345 3789 61875 16264 50799 20761 29352 44796 75809 ESO 64 n= ‘00100 00000 C0153 30399 do044 06000 60008 65960 92825 14227 06303 41365 50645 63522 06215 12108 84946 96404 61971 02278 When 2 == 1000 :— m='00900 00833 33333 33333 73015 87301 59487 73448 77428 21067 8213 382165 00876 92580 99464. 82 37182 41954. 63931 48991 n= 00050 00000 00008 30999 59939 31000 00000 00210 92796 09325 95526 00040 82093 23718 92820 00915 30532 37715 49061 83360 The calculation was performed to 105 places, and the last two figures have been rejected. 524 Sir W. Thomson’s Amended Rule for working [June 15, POSTSCRIPT. Received June 14, 1871. After the completion of the above paper, the author found that Mr. Shanks had, in second, third, and fourth supplementary papers on the Constant*, extended his calculations so as to determine y from e=2000, 5000, and 10,000. The values so obtained all differ in the sixtieth decimal; in fact the higher « is taken, the further from the truth are the results, as the errors in the logarithms are multiplied by larger factors. The calculation for c= 2000 affords a verification of the error of log 2 ; for on subtracting the value of y (v=1000) from y (v=2000), we obtain (after correcting B,,) a result agreeing with E to 80 decimal places (which is as far as Mr. Shanks has calculated the latter value of y), with the exception of a difference of a unit in the 73rd figure—an error pro- bably in the summation of the harmonic series from 1000 to 2000. The values for z=5000 and x=10,000 are (besides the errors pre- viously noticed) inaccurate from the 62nd figure. VIII. “ Records of the Magnetic Observations at the Kew Observatory. No. [V.—Analysis of the principal Disturbances shown by the Horizontal and Vertical Force Magnetometers of the Kew Ob- servatory from 1859 to 1864.” By General Sir Epwarp Sa- BINE, K.C.B., President. Received June 15, 1871. (Abstract.) This paper exhibits an analysis of the principal disturbances recorded by the horizontal and vertical force self-recording magnetometers of the Kew Observatory in the years 1859 to 1864, showing the progressive diminution in the number and value of the disturbances from a maximum in 1859 to a minimum in 1863, being the first moiety of the “ decennial period ;” and showing also the distribution of the disturbances, increasing or diminishing the respective forces, in the several years, months, and hours. IX. “ Amended Rule for working out Sumner’s Method of finding a Ship’s Place.” By Prof..Sir Witt1am Tuomson, F.R.S. Received June 15, 1871. In my previous communication on this subject (antec, p. 259) I described a plan according to which, in the first place, two auxiliary lines were to be drawn on the chart, from two sets of numbers taken out of a proposed Table, and then Sumner’s line (the line on which the observation shows the ship to be) was to be interpolated, dividing the space between them in the proportion of the differences of the sun’s decli- * Proc. Roy. Soc. vol. xvi. pp. 154, 299, vol. xviii. p. 49. 1871.] out Sumner’s Method of finding a Ship’s Place. 525 nation from two of the tabular numbers. I find a better plan in practice to be as follows :— (1) Take two solutions out of the Table as directed in my previous paper. (2) Taking the two hour-angles and the two altitudes from these two solutions, interpolate to the nearest minute the hour-angle and the altitude corresponding to the correct declination, according to the simple proportion of its differences from the declinations of the two solutions ; and estimate, by inspection, the proper azimuth to the nearest half degree, from the azimuths shown in the two solutions. (3) -Using the interpolated hour-angle, azimuth, and altitude found by clause (2), find on the chart, in the assumed parallel of latitude, the point whose longitude is the differenee between the interpolated hour-angle and the Greenwich hour-angle at the time of the observation; through this point draw, by aid of a protractor, a line inclined to the north and south at an angle equal to the azimuth, and on the proper side according to whether the observation was made before or after noon; on this azimuthal line* measure off towards the sun a length (miles for minutes) equal to the correct altitude of observation above the interpolated altitude of clause (2) ; and through the point thus reached draw a perpendicular to the azimu- thal line. This perpendicular is Sumner’s line. The Table (of which a specimen page was shown in my former commu- nication) has now been completed by Mr. Roberts, and has been in my hands long enough to allow me to test its use in actual practice. I find the assistance of compasses for measuring off the assumed colatitude preferable to the slip of card with numbers which I first suggested ; and I find the process to be altogether very easy and unfatiguing (in respect to fatigue a great contrast to the ordinary method). I find that all the cases (as azimuth and hour-angle both acute, azimuth acute and hour-angie obtuse, or azimuth and hour-angle both obtuse, or, again, declination greater than latitude, but of same name, and declination of opposite name to lati- tude) work out without ambiguity or perplexity. Still the mere fact of there being different cases may possibly deter practical navigators from leay- ing the ordinary method, which, though considerably longer and much more laborious, has the excellent quality of presenting no variety of cases. I intend, however, to push forward the preparation of a short paper of prac- tical directions, illustrated by examples of all ordinary and critical cases, and to publish it with the Table; so that practical men may have an Opportunity of judging from actual experience whether the plan of working Sumner’s method which I have proposed will be useful to them or not. I thought it unnecessary in my former communication to remark that every determination of longitude at sea (except from soundings or sights * Tt is unnecessary to mark this azimuthal on the chart. By holding one side of a “ set square” (or other proper drawing instrument for making right angles) along the azimuthal line, the Sumner line perpendicular to it is readily drawn, and this ‘‘Sumner line,” or line of equal altitude, is the only mark which need be actually made on the paper. 526 Mr. Russell on Linear Differential Equations. [June 15, f land interpreted in connexion with observations for latitude) involves the unknown error of the chronometer, and makes the ship 1’ West or East of the-true place for every four seconds of time that the chronometer’s indication is in advance of or behind correct Greenwich time. Although I believe that every man who uses a chronometer at sea knows this per- fectly well, I shall not omit to state it in the practical directions which I propose to publish, as the Astronomer Royal, Professor Stokes (‘ Proceed- ings,’ April 27, 1871), and Mr. Gordon (writing in the ‘ Mercantile and Shipping Gazette’) are of opinion that an explicit warning of the kind might be desirable in connexion with any publication tending to bring Sumner’s method into more general use than it has been hitherto. X. “On Linear Differential Equations.”—No. V. By W. H. L, Russert, F.R.S. Received June 15, 1871. Let us now endeavour to ascertain under what circumstance a linear differential equation admits a solution of the form P log, Q, where P and Q are rational functions of (2). d”y qd? y If (ata, e+ ae ) ae t (Bot Be + is 7 7 wrareats ce peel) -we have, substituting y= P log, Q, d”P dp ‘ | (aa-baye-+ See ) ae t (Bot Bye + rae +) ged a ai \ log. Q+R=0, where R is a rational function of (2). Hence d"P y di? 1p (a,taaet ....) Fan + (Pot hat - . --)a,e1 ih sae or P must be a rational function satisfying the given equation. Having ascertained its value, we have a differential equation of the form d” log. Q d’— log. Q Li tL pe Ey lee ee Divide this equation by L,, and differentiate, and we have an equation of the form ad’ log Qi d” d" log. Q On dlog.Q / ae: M, 2 { pom i . 0 dgt ax nr 2 M, dx 0 > from which we find Q in all possible cases, since ~— is a rational xv function of (#). It is impossible that a linear differential equation can in general have a solution of the form y=/f(log.) ; for in that case we should have pee Bir 8) gg wl PCE) + (y+ Be+ Bi es —— pos s'==0, Let z=log.w, and the equation becomes of the form (a,4-e,e7+a,e% +... JO 4 6,4 b,0°4 bert... — 1871.] Mr. Russell on Linear Differential Equations. 527 and putting for z successively z+ 277, e+477,... ., the equation becomes (a, +a,e*+a,e"7+....) tyle+ Oni) og +b, +b,e7+. dz alt d’ "f(z +4) fe oe WR i oe : (q,+ae%+a,e"+... )AEEAO + be + b+ plait Cae it -4art) =) deta &e. == We. where these equations can be indefinitely continued. Let us now see what are the conditions that a linear differential equation can admit of a solution y=P+/ Q, where P and Q are rational functions of (x). Itis evident that P and Q must satisfy the differential equation separately, so that we may confine ourselves to the case of y=4/Q. We observe that the factors of Q must also be factors of the coefiicient of the highest differential; 7. e. if ajtae+ae+ ....=(e—a)"(a—b)....4/Q=(a@—a)e(w—b)”. Let v=a+ 1871.] Theory of the Ocean. 551 Postscript, June 23rd, 1871. As the undercurrent theory, in its larger view, as first put forth by Capt. Maury, will remain a source of error still for the misguidance of the phy- sical geographer and philosopher, whilst the fallacy or mistaken facts also remain uncontradicted, upon which it was mainly and originally founded by the eminent author of the ‘Physical Geography of the Sea,’ it is therefore now necessary for me to show, after what I have previously written on the question, that the assertion of an undercurrent of from 1 to 13 knot per hour in the Atlantic as counter to a surface-current of much smaller amount on the outside of the Gulf-stream, is based upon a mis- taken estimate of the results of the experiments that were supposed to indicate such an undercurrent. Capt. Maury says, in p. 141, ‘ Physical Geography of the Sea,’ when discussing his undercurrent views in the chapter headed ‘ Undercur- rents :?— «Lieut. J. C. Walsh, of the United States schooner ‘ Taney,’ and Lieut. 8. P. Lee, in the United States brig ‘ Dolphin,’ both, while they were car- rying on a system of observations in connexion with the wind and current charts, had their attention directed to the subject of submarine currents. They made some interesting experiments on the subject. A block of wood was loaded to sinking, and by means of a fishing-line or a bit of twine let down to the depth of 100 or 500 fathoms; a small float, just sufficient to keep the block from sinking further, was then tied to the line, and the whole let go from the boat. ‘‘To use their own expression, it was wonderful, indeed, to see this dar- vega move off against wind and sea and surface-current at the rate of over one knot an hour as was generally the case, and on one occasion as much ag 13 knot. The men in the boat could not repress exclamations of surprise ; for it really appeared as if some monster of the deep had hold of the weight below, and was walking off with the line. Both officers and men were amazed at the sight.”’. In paragraph 273 he says, ‘‘ It may, therefore, without doing violence to the rules of philosophical investigation, be conjectured that the equilibrium of all the seas is preserved, to a greater or less extent, by this system of currents and counter currents at and below the surface. If we except the tides and the partial currents of the sea, such as those that may be created by the wind, we may lay it down asa rule that all the currents of the ocean owe their origin to difference of specific gravity between sea-water at one place and sea-water at another; for whenever there is such a difference, whether it be owing to difference of temperature alone or difference of saltness, &c., it is a difference that disturbs equilibrium, and currents are the consequence. The heavier water gives towards the lighter, and the lighter whence the heavier comes ; for two fluids differing in specific gravity, and standing at the same level, cannot balance each other.” 552 Captain Spratt on the Undercurrent [June 15, From the above reasonings, it is clear that the eminent author, from the supposition that a great undercurrent movement in the Atlantic had been discovered as the result of the observations and experiments of Lieutenants Walsh and Lee, was induced to propound his fascinating but fallacious theory regarding the origin of “‘all the currents of the ocean”’ being more due to temperature and density than to tides and winds. Now it is true in regard to tides, that is, the currents resulting from tide- waves are mainly littoral and local. It is not so, however, as the result of winds, which from my experience are the main sources of ocean-currents, without ignoring that from the rotation of the earth, which are therefore chiefly superficial, but capable of reaching a considerable depth where the — water is deep enough, even to 50 and more fathoms, with no greater sur- face-movement than from three-tenths to five-tenths, or half a knot per hour, as I have on several occasions experienced from a perfect stillness of the sea from the surface down to the greatest depths in perfect calm weather, but which was set in motion in the same direction as the wind to that depth a few hours only after a 4- or 5-knot breeze had set in. To show that Capt. Maury had mainly founded his theory upon the ob- servations of Lieutenants Walsh and Lee, I must quote from the Report of the former as being the one most important and complete, as was sup- ’ posed, in proof of the rapid undercurrent believed in by Capt. Maury, and supposed to have been confirmed by other phenomena connected with the fallacious idea of the ploughing of icebergs through fields of ice in Baffin’s Bay, by the force of a mighty undereurrent*, instead of the fact of the field of ice flowing past them, by reason of the greater strength of the surface-current over the current in the depths to which the base of the bergs reached, as no doubt must be the fact in that bay or strait from the southerly drift of both into the Atlantic. ‘Report of Lieut. Walsh, U.S.N., to Lieut. M. F. Maury, of the Ob- servatory at Washington. | ‘The next subject to which I would refer is our investigation of the undercurrents of the ocean. I regret we had so few opportunities for the interesting experiments, but enough has been done to seem to warrant the conclusion that these undercurrents are generally stronger setting in various different directions than those of the surface. I am well aware there is no mode of testing their exact velocity, but that practised by myself, which I will describe, was certainly all-sufficient to show their real velocity. There may be none so rapid as that mighty ocean-river the Gulf-stream. Unfortunately the weather prevented our making these investigations in that interesting region; but in the various parts of the Atlantic in which we succeeded in these experiments, on only two occasions did we find the undercurrent of less velocity than that run- ning in a different direction above it. * See Physical Geography of the Sea, pp. 162 & 163. 1871.] Theory of the Ocean. 553 «“The following is the mode practised: the surface-current was first tried by the usual mode (a heavy iron kettle being lowered from a boat to the depth of 80 fathoms), then for the trial of the undercurrent a large chip-log, of the usual quadrantal form, the arc of it measuring full 4 feet, and heavily loaded with lead to make it sink and keep upright, was lowered by a light but strong cod-line to the depth of 126 fathoms (the length of the line); a barrega was attached as a float, a log-line fastened to this barrega, and the rate of motion to this float, as measured by this log-line and the glass, and the direction as shown by a compass, were assumed as the velocity and set of the undercurrent. No allowance was made for the drag of the barrega, which was always in a different direction from the surface-current. It was wonderful, indeed, to see this barrega move off against wind and sea and surface-current at the rate of over one knot an hour, as was generally the case, and on one occasion as much as 13 knot. The men in the boat could not repress exclamations of surprise, for it really appeared as if some monster of the deep had hold of the weight below, and was walking off with it.” It is therefore quite evident that Capt. Maury adopted Lieut. Walsh’s identical words and views as the sound solution of the experiments, viz. that a great oceanic undercurrent circulation existed as a counterpoise to the disturbed densities arising from temperature and salinity. Lieut. Walsh next cites from the log several instances of the experi- ments, viz. at six positions in the Atlantic, between 24° 43’ North and 0° 2’ West, and 33° 58’ North and 72° West, in which the weighted chip- log was lowered to 126 fathoms in each position, to test the undercurrent at that depth, as erroneously supposed. But in fact it was merely giving a more correct indication of the surface-current than that resulting from the iron kettle in 80 fathoms, witha large boat as its float, under the erroneous impression that the iron kettle would be in still water at that depth, and that 1t would retain the boat stationary as if anchored to the bottom; this, too, against wind and sea. Itis, however, evident that the kettle-and- boat experiment could only show a vitiated result, a Capansies surface- current to that actually existing. 5 The kettle-and-boat experiment were only used once, however, at the last position, in connexion with the large chip-log lowered down to 126 fathoms, which Lieut. Walsh Beetle, by saying, “which it would have been better to have always done.” _ Now it must be quite evident from what I have before shown, from my experiments for testing surface and undercurrents, or from the diagram referred to, p. 537, how the rate of descending surface-currents, and of any undercurrent, can be correctly ascertained, if existing as an appreciable fact, although Lieut. Walsh did not then know “of any means of doing so correctly ;’’ that, therefore, the float to the large 4-feet diameter chip- log, lowered down to 126 fathoms, would naturally appear to run to windward of the heavy boat attached to the iron kettle of less dimension g 554 Captain Spratt on the Undercurrent [June 15, than the former, and therefore of less resistance to the drag of the boat by the wind, sea, and surface-current, even if both kettle and chip-log had reached the region of perfectly still water. But if, as may have been probable, the kettle was still in a portion of the surface-current, and the chip-log in about 50 fathoms lower down was in the still regions, or even a more diminished rate of the surface-current, the float of the latter would more rapidly separate from the boat in the opposite direction to the surface-current, and thus appear to be marvellously dragged by an undercurrent against wind and sea and surface- current—that is, against or opposite to the boat’s natural drift. Now, as Lieut. Walsh notices that the weather was too rough for attempting deep soundings, except on the 14th of May, we must infer that there was sufficient wind and sea to cause considerable drift to the boat; but he does not notice the direction of the wind. : Therefore, as there was no fixed object as a point of comparison suffi- ciently exact in the last experiment, when the kettle was used, much less in the others, when only the chip-log was used, and with a compass bearing from a drifting boat for ascertaining the presumed direction of the under- current, even the true direction of the surface-current cannot be depended upon by reversing the direction he has given for the undercurrent (this is, by assuming that the surface-current ran E.N.E. 13 knot when he gives the undereurrent as setting W.S.W. 1} knot), since there were so many sources of error vitiating the results. A fixed object for reference can always be obtained in any depth by a 20-lb. lead and sufficient twine, and a light float attached when it has reached the bottom, as I have long since shown and recommended as a necessity in all such delicate experiments in mid-ocean or elsewhere. The following are the results at the six posi- tions given by Lieut. Walsh :— ; : Oat Temperature,| Fathoms, Date. Lat. | Long. |Depth.| Rate. | Direction. SrA, 0. Aare are etmel @ tcnok, - May llth ...| 24 43 | 65 2 126 1 W.S.W. 77:3 73°95 May 12th ...| 24 55 | 64 43 | 126 13 S.E. 7d 69 May 13th ...| 26 42 | 64 41] 126 4 W.S.W 175 745 May 14th ...| 26 46 | 63 53 | 126 + | N. by E 77 May 18th ...} 30 06 | 67 56 | 126 = N.E. 70 65 May 29th ...| 338 58 | 72 00 |. 126 1 W.N.W 71 67 It is therefore only the rate as given above for the undercurrents that can be relied upon as the rates of a surface-current that really existed in those positions, and which from the high mean temperature for the whole six, of 74°'6, and of 77°'3 at three of the positions, as the surface-temperature for the month of May, and of 73°5 and 74:5 in a depth of 100 fathoms at two of them, would seem to show it to have been a continuation of a portion of the trade-wind or equatorial current, its easterly portion running outside of the West-India Islands, but somewhat checked, and even perhaps at times 1871.] Theory of the Ocean. ‘555 diverted by the local winds; forthe power of winds to divert even the ‘‘mighty Gulfstream” of 34 knots is shown in the ‘ Notes on the Gulf-stream,’ by A. D. Bache, Superintendent of the United States Coast Survey, who shows it to be driven sometimes out of its usual course fully thirty miles by N.W. and westerly gales. In concluding these remarks upon the errors regarding the under- current theory, I feel that it is due to our distinguished transatlantic hydrographers and geographers, that as theirs were the pioneer efforts in such investigations on a large scale, it was natural that they should have been defective, from the little attention given to such researches previously. But it is necessary that these errors should now be well understood, and ‘shown to have arisen from a fallacious estimate of the experiments, that the philosophical naturalist and physicist be no longer misguided by them, and thus attribute so grand and large an influence to undercurrent, as erroneously shown by the experiments of Lient. Walsh and Lee, and as the assumed necessary result of the small difference of density between one part of the ocean and another ; for surface-current circulation and return -can and, indeed, must tend largely to restore it, aided by the rain and river supply of fresh water met with in its circulation and return. This is even shown to be so under the equator, from the large African rivers and also from the Amazon and others joining the equatorial current, from the elaborate investigations (the twenty years’ researches) of the late Dr. -Forchhammer, as surnmarized in his most interesting and valuable dis- cussion of these analyses in hig paper in the Philosophical Transac- ‘tions for 1865, wherein the analyses and temperatures of the sea- water are given from all parts of the globe, and a most remarkable and able deduction of the surface-currents from them. But the learned Doctor, misguided, no doubt, by the supposed existence of the great undercurrent movement in the Atlantic as propounded by Capt. Maury, and also by the ‘misunderstanding of the facts and the incompleteness of the observations for correctly ascertaining the conditions existing between the Baltic and German Ocean, and so, as a philosophical physicist, thus misled, was in- duced to ascribe a greater influence to undercurrent circulation than to superficial, as a means of restoring the equilibrium from reduced or increased densities. I have before admitted that where two currents meet, such as the Polar and Gulf-stream, both strong in force and of great difference in density or temperature, and in directions nearly at right angles such as these two, an undercurrent or intermediate current of appreciable amount may exist. That denser water will intermix with lighter water in its deeper portion, when they meet and when depths are equal and difference of the densities great, as between pure fresh and sea-water, 1 am aware from my experi- ence at the mouths of large rivers. This is a fact experienced every year at the Damietta and Rosetta mouths of the Nile for five or six weeks, during the lowest condition of the Nile, when there is only a surface-outflow there; and it extends five or six miles e 556 Dr. R. Norris on the passage of [June 15, within their embouchures, as I first ascertained when carrying out my current tests in that river; brackish water was consequently found in the lower depths, percolation of sea-water through the sandy substrata no doubt then partly accounting for its brackish condition. But eddy surface-currents along the sides of the river, under the influence of the prevailing N.W. winds blowing directly into the mouths, no doubt also assist the intermixture as far as it goes—just as the return-current down the European coast is diluted and intermixed in its general and superficial density from the rains and rivers of the north, and thus tends to restore the lost freshness of the equatorial or trade-wind and Gulf-stream cur- rents, as the tropical rivers and rains tend to restore the loss in the low latitudes: thus condensation from evaporation and redilution by surface- currents are throughout mainly maintaining the equilibrium. Dr. Forch- hammer shows. that this lighter density or dilution of the encircling super- ficial waters from the equator commences from the American rivers from the parallel a little north of the Bermudas, and that it exists all along the European coast and again on the African coast from the African rivers ; and he has shown that the effect of the La Plata is found 900 miles from its mouth. The fact I have given of the condition at the Nile’s mouths at certain seasons is an extreme case, quite in accordance with the great undercurrent theorists’ views, and I mention it as a fact of interest to them. But nevertheless I believe, from my own experience, and from the facts to be gathered from Dr. Forchhammer’s elaborate researches into the tempe- ratures and saline densities, that as it is not an appreciable and measurable movement as an undercurrent at the Nile or Dardanelles, and only chemi- cally testable by the tongue or hydrometer, so are there no great mechanical and appreciable movements as undercurrents in the ocean as a necessary result of the very slight difference in the densities of one part of the ocean and another. Nevertheless a complete investigation into the phenomena of ocean-currents is a most desirable operation, and can be so easily accom- plished on the plan I have found so practicable and easy, and recommended several years ago for adoption by all scientific captains when crossing the great oceans, especially when calins detain them and favour the experiment, without fear of the results being confused or mistaken ; for then only should it be carried out where there are great depths and where strong surface- currents exist. XII. “ On the Physical Principles concerned in the passage of Blood- corpuscles through the Walls of the Vessels.’ By Ricnarp Norris, M.D., Professor of Physiology, Queen’s College, Bir- mingham. Communicated by Dr. Suarrry, Sec. RS. Re- ceived June 12, 1871. In the year 1846 my much-lamented teacher, Dr. Augustus Waller, published in the Philosophical Magazine two able papers relating to the 1871.] Blood-corpuscles through the Walls of the Vessels. 557 perforation of the capillaries by the morphological elements of the blood, viz. the red and white corpuscles. These observations attracted little attention till the year 1867, when the facts made known by Dr. Waller were rediscovered by Professor Cohnheim, of Berlin. Since the publication of Cohnheim’s researches very considerable interest has been taken in the subject, and the experiments have been repeated and the facts corroborated by eminent physiologists and pathologists in all parts of the world. On a careful consideration of the hypotheses which have been propounded by Waller, Cohnheim, Stricker, Bastian, and Caton, to account for the curious phenomena in question, it will be found that all these hypotheses fall short in one important particular, inasmuch as they afford no explanation whatever of by far the most singular part of the process, viz. the fact that the apertures through which the corpuscles pass again close up and become invisible. The question, indeed, is not so much how the cor- puscles get out, as how they get out without leaving any permanent trace of the apertures through which they have so recently passed, and which were so palpable during the period of transit. Before proceeding to elaborate my own views, it may be well to restate succinctly the various pomts upon which observers are agreed. Ist. Both white and red corpuscles pass out of the vessels through apertures which can neither be seen before their ingress into or egress from the vessel wall, but only during the period of transit. 2nd. An essential and primary step in the process is, that the corpus- cles shall adhere or, more properly, cohere to the wall of the vessel. 3rd. These cohering corpuscles shall subsequently be subjected to pres- sure from within. With these conditions fully before our minds, we will proceed to inquire if in physics we can find the analogue of these seemingly mysterious phe- nomena. In the first place, this phenomenon of the passage of bodies through films or membranes is by no means confined to the capillary walls, the same thing has been observed in nucleated blood-corpuscles, such, for ex- ample, as those of the frog. In these cases no rupture or aperture of exit has been discovered. It is obvious that the escape of the nucleus from its capsule without rupture, and the passage of the entire blood-corpuscle through the capil- lary wall without rupture, are phenomena of the same class; and the ex- planation which will suffice to clear up the one, will also apply with equal force to the other. - As a matter of fact, it will be admitted that we can form no @ priori conception of one form-retaining body passing through another without either rupturing it or distending certain holes or pores which it may al- ready possess. ‘This, however, is just one of those cases in which con- 558 Dr. R. Norris on the passage of [June 15, ceivability is no test whatever of possibility. To comprehend these phe- nomena it is necessary to bear in mind the ultimate constitution of the animal membranes, which form alike the capsules of the corpuscles and the parietes of the capillaries*. All the membranes which enter into the animal body may, from a physical point of view, be divided into two orders, —the very fine structureless homogeneous films which must be regarded as simple cohesion-membranes, in contradistinction to the second order of coarser membranes, to which certain mechanical arrangements are super- added, which have the effect of increasing the strength, such, for example, as structure, the result of interlacing fibres; in films of collodion, gelatine, albumen, india-rubber, and soap we have examples of the first class of mem- brane. It is with this class that we are now concerned, and these are sus- ceptible of two states, the fixed or rigid condition, and the contractile or elastic state, dependent upon the presence of the principle of “ flow,” which principle may be operative in every shade and degree, from perfect liquidity to absolute rigidity. | It will be sufficient to state here that the more colloid and plastic those membranes are, or, in other words, the more they approximate in their con- stitution to liquids, so do they proportionately cease to obey exclusively the laws of rigid bodies, and begin to exhibit intermediate properties or quali— ties, some of which belong to solids and others to liquids. We may take the soap-film as the best illustration we can find on a large scale of the class of homogeneous cohesion-films, possessing in the greatest perfection this principle of “flow,” and as exhibiting to the fullest extent phenomena which I have generalized under the term progressive cohesive attractions. By the study of the soap-film we may acquire a knowledge of many * The parietes of the capillaries are held by modern histologists to consist of pro- toplasm, a substance which is universally considered to be of a viscid semiliquid nature, and in which it is easy to demonstrate the presence of the property of flowing within ~ certain limits. {+ The term progressive cohesion is here used in contrast with that operation of cohe- sion which simply maintains contact between the particles of two like or unlike sub- stances or bodies, and which, when it occwrs between the particles of unlike bodies, is called adhesion. ‘The attraction of cohesion evidently operates for some distance beyond the atom or particle, so that actual contact is not essential to its display. "When two small globes of mercury, or of any other liquid, are made to touch at one point, they merge, as is well known, with great rapidity into each other, and the materials which compose them become arranged around a common centre, that is to say, one larger sphere results. The mode of union of these two spheres is clearly a progressive one, the particles nearest to those in actual contact being the next to come into contact, and so on, until the globes become intimately united. In the presence of gravitation there can be no mass-attraction between the two globules. Again, when a solid is partially immersed in a liquid having a cohesive affinity for it, e.g. a sheet of glass, the liquid, as is well known, rises considerably above the water- level. This shows that with unlike bodies the action extends beyond contact, and is progressive in its operation from one line or row of particles to the next above. This term therefore includes all effects of cohesion which arise from and display its opera- 1871.] Blood-corpuscles through ihe Walls of the Vessels. 559 of the laws which are operative in connexion with delicate colloidal films in general. The steps, for example, in the production of an ordinary soap-sphere are very remarkable, as exemplifying the power which these films possess, under the influence of progressive cohesion, to perfect any absence of con- tinuity which may exist in their structure. The first essential in the process of forming a soap-sphere is the pro- duction upon the mouth of the pipe-bowl of a film stretching evenly across from every point of the circumference. The production of this film is a far more complex operation than is generally supposed. If for the pipe-bowl we substitute a ring having a diameter of from 12 to 18 inches, we are enabled to watch, as the process proceeds, the manner in which the film is formed. Having submerged the ring in a solution of soap, we observe, as we gradually raise it out, that its circumference brings up from the liquid a band-like film of a cylindrical or tubular form which is attached to the ring above and the liquid below; raising up the ring still higher, we find that this annular film contracts in diameter at every part except at its at- tachment to the circumference of the ring, which is of course fixed. This quality of the film to contract between opposing points of extension causes it to take on the shape of an inverted cone with curved sides, the convexities of which are directed inwards. The tendency to assume the inverted-cone shape is further assisted by the fact that the film, in con- tracting, travels inwards upon the surface of the solution towards a central point, so that from the ring downwards to the surface of the solution the diameter of the tubular film is continually decreasing. The shortest diameter is not, however, immediately upon the surface of the liquid, but at a little distance from it; and consequently, as the contraction proceeds, it will be at this spot that the union of the sides of the film and the separa- tion will take place. This arises from the fact that this is the weakest point of tension between the ring and the liquid, and therefore the one in which circumferential contraction can take place with the greatest ease and effect. ‘Thus we see that the tubular film which we have raised really be- comes constricted into two portions,—an upper portion, which immediately contracts into a plane surface upon the ring, and a smaller and lower portion, which, in consequence of including air, becomes a hemisphere and remains attached to the surface of the solution. If, having formed such a film upon a ring or pipe-bowl, we proceed to blow down upon it, we distend it into a sphere; but it is obvious that until the sphere is detached tion beyond the line or boundary of actual contact. All capillary phenomena may be regarded as due to this progressive action of cohesion operating at one and the same time in diverse directions. 560 Dr. R. Norris on the passage of [June 15, there exists a free opening into it at its upper part, which becomes suddenly sealed up by cohesion of the sides of the film at the moment preceding detachment ; and this detachment is seen to be a repetition of what takes place in the formation of the primary film. The next point to which I would draw attention is the power possessed by these films to repair breaches of continuity that may be made in them subsequently to their formation. If any rigid body be wetted, it is quite possible to thrust it through one of these films, move it about, and again withdraw it without interfering with the integrity of the structure, as may be proved by passing a aeeeet bulbous rod of glass through the film. It is not, however, essential that the body should be either smooth or regular, for the same thing may be done with the naked fist and arm. I have fovea elsewhere that the blood-corpuseles undergo a mode of aggregation in obedience to progressive mutual attraction in pre- cisely the same fashion as soap-spheres,—that is to say, if they touch at any one point they gradually, by the operation of double cohesion (capillary at- traction), convert each other into polyhedral-shaped bodies*. If we wet any smooth rigid surface and allow one point in the circumference of a bubble to impinge against it, we find that it becomes so drawn down to the plate in every direction, from this point as a centre, as to take on a hemi- spherical form. But if for the rigid surface we substitute a delicate flowing film, such as the soap-film, and allow the bubble to come in contact with it at one point, taking care that there is a free supply of liquid upon its exterior at this point, we observe that the result is different. In this case the soap-sphere takes on the form of two watch-glasses in apposition at their edges, one of the curves being present on each side of the film. The soap-sphere has, in fact, penetrated the film, and arranged itself so that half is on one side and half on the other. Now this is precisely analogous to what takes place with the capillary when the corpuscle has entered into cohesion with its wall; “a ee rance is seen on the outer surface.” If we can subject this soap-sphere to pressure on one side only, we shall cause it to protrude through the film still further; this we can do by forming one sphere within another. This inner sphere protrudes more than in the case of the simple film. That there is pressure within a bubbie may be known by the fact that, if left with an aperture in it, it will gradu- ally force out the contained air and become again a simple film by its strong cohesive tendency. Further, it will be seen that we can with the greatest ease separate these cohering spheres, bringing them bodily through the film without injury to one or the other ; and this may be taken as a parallel case to the passage of the nucleus through the capsule of the corpuscle, and of the Ba itself through the capillary wall. I have previously shown that the corpuscles are raneate to the same * Proceedings of Royal Society, vol. xvii. p. 429. 1871.} Blood-corpuscles through the Walls of the Vessels. 561 laws as the soap-spheres, and we have only to infer that they bear the same relation to the capillary walls as these spheres and films bear to each other. The margin of speculation is therefore small. In the case of the corpuscles this relation is of course only seen under abnormal conditions, simply because it is a physical law which in the normal working of the animal economy required to be antagonized. It must also be observed that it is only under certain conditions that the soap-spheres attract each other, or are attracted by rigid surfaces or plastic films. This occurs only when free liquid is cohering to their surfaces. If before bringing them into contact we allow the soap-film and sphere to become moderately dry, they will not attract each other, but the former will support the latter as a perfect sphere instead of drawing it down by progressive cohesion and arranging it halfway through itself. Just so with the corpuscles; they do not unite either with each other or with the capillary wall, unless their normal osmotic relations are disturbed, the exosmotic current setting in excessively when their external surfaces become coated with content-matter, and they become instantly attractive of each other, of the capillary wall or glass slide, as the case may be. In the paper before referred to, “‘ On the Laws concerned in the Aggre- gation of the Blood-corpuscles,”’ I have given numerous examples of the operation of progressive cohesive attraction; but in this place I wish to call attention to the demonstration there given of its relation to plane sur- faces. Taking this experiment as a starting-point, we will extend the consi- deration to surfaces of a different character. In the first place, we find that this law continues to operate with great facility in connexion with surfaces curved in one direction only, whether the surface used be convex or concave; in both eases the film of paper or collodion applies itself evenly to the surface in the gradual progressive manner before explained. If, however, for surfaces curved in one direction only, we substitute such as are curved in all directions (for example, the outer or convex, or the inner or concave surfaces of a hollow sphere), we find ourselves confronted with a new set of difficulties, out of which we may evolve the statement that, for any film to apply itself evenly and regularly to either the convex or concave surface of a sphere under the influence of progressive attraction, it is necessary that the film should be, in several particulars of its consti- tution, very different from the class of films by means of which we have been able to illustrate the three preceding experiments. If, by way of illustration, we apply a film of wetted collodion or fine cambric paper to the sphere, so that one point of the convexity of the latter may come in contact with the centre of the film, the attraction will only succeed in pulling it down to the surface of the sphere at certain points ; the intermediate puckered parts are not in contact, and can by no possibility become applied. From this we see that for the film to be laid down evenly, it would be necessary that it should contract in certain parts, VOL. XIX. 2x 562 _ -Dr. R. Norris on the passage of °) [June ds, that, in fact, the puckered or surplus material should be taken up. We may say, then, that any film which can adapt itself to the surface of a spherical body must possess the twofold quality of facile contraction and expansion, these qualities being controlled in their operation by progres- sive cohesive attraction. Such a film must be a simple colloidal cohesion- membrane in possession of the property of “ flow.” Further, if we apply to a sphere a film known to possess facile proper- ties of expansion and contraction under the influence of slight forces, such as progressive cohesive attraction, the first thing seen to occur is cohesion of the film to the sphere at the point of contact ; and from this point as a centre of operation the film proceeds to apply itself gradually in all direc- tions, so that the sphere becomes coated or covered evenly by it: this process goes on till such time as the attraction becomes balanced or fully antagonized by the elasticity of the film, that is to say, the attraction is only powerful enough to stretch the film to a certain extent; so that if the rigid object be fixed, as is the case with the glass bulb when held immoyably, we get a flattened form of the film. A sufficient degree of attachment of the film to the bulb has taken place to stretch the former backwards out of its normal plane. If, now, we push the bulb further forwards, the film still continues to apply itself to its surface, and having reached the equato- rial line of the sphere, descends on the opposite hemisphere till the bulb is completely coated. But it will be said the bulb does not then really produce an infraction of the film, but merely attracts it down to its surface, and in so doing stretches it, so that it is in reality a new conformation of the film and not a breach of its continuity. That this is true to a certain extent there is no doubt, but it is not all the truth; for we may wipe the bulb dry after it has passed through the film without interfering with the continuity of the latter. All that appears to be necessary for these effects to display themselves is, that there should be mutual cohesion between the film and the body passing through it; for if we press against one of these delicate films with a substance which has no cohesion for it, e. g. a current of air or a dry soap-sphere, it simply distends the film, neither bursting it nor giving rise to an aperture init; while in the case of a body to which the film can cohere, it would appear to be easier for the latter to allow the passage of the cohering body than to suffer distension by it, and this be- cause it has under these conditions as great an attraction for the particles of the body as for its own particles. When the cohering body has become perfectly applied to the film, the latter, by the cohesiveness of its own particles, contracts to the greatest degree possible consistent with still main- taining its attachment to the cohering body; and this in spherical-shaped bodies leads to a condition of things in which half the body is within and half without the film or wall*; therefore the rest of the process must be * An excellent illustration of this principle is afforded when a light india-rubber ball or balloon. is suspended from a fixed point, its surface having previously been wetted with a solution of soap. When a soap-film formed upon the ring, as in the previous 1871.|] Blood-corpuscles through the Walls of the Vessels. 563 accomplished by pressure from within. It is easy to see that the manner or degree to which the corpuscle or body coheres to the film will deter= mine very materially the method of its transmission. All, then, that is essential fora rigid or plastic body to pass through a colloid film is :—I1st, an intimate power of cohtsion, either mediately or im- mediately, between the film and the body; 2nd, a certain amount of pres- sure from within; 3rd, power in the substance of the film to cohere to the surface of the body (or to some intermediate matter which already coheres to the surface) during its passage; 4th, cohesive plasticity of the particles of the material of which the film itself is composed, so that the breach in it may again become reunited as it descends upon the opposite suirface of the body which is being extruded. It is quite remarkable to how great an extent these conditions appear to be complied with in the passage of the white corpuscle through the capil- lary wall, as affirmed by independent observers. In the factitious examples by which I have sought to illustrate these effects, the film moves over the body, or the body through the film, by virtue of the intermediate agency of the solution which has cohesive at- traction for both; and the film does not rupture, because, while the body is travelling through, it can continue to cohere till such time as it is brought again into contact with its own particles at the opposite pole of the extruded body. Theoretically, as it leaves the sphere or protruding body, the aperture should gradually narrow to absolute union at a focal point, or, according to the laying-down view, having resealed itself from the bulb; practically, however, I find that the film rarely leaves the bulb or sphere without form- ing on it a small hemispherical bubble, which is large in the ratio of the rapidity with which the detachment is effected. If detached with very great care, the bubble is exceedingly small; but I could not succeed with a spherical bulb in getting rid of it altogether ; with a more conical bulb, however, this was readily effected. In the case of the sphere, the film is in reality drawn out into a little neck, as in the other examples in which continuity is effected; and this neck is pulled into two, and both parts cohering at the point of severance, we get on the one side the perfected film, and on the other a small enclosure of air which takes on the hemispherical form. This is owing to the annular contraction of the tubular part. If the body were small or less spherical, or the film a trifie more rigid, this would not occur. I find, in fact, by experiment that smaller bodies, more conical in their termina- tion, do not. do this, but draw out a kind of streak of solution as they leave the film—a fact I have often observed with the white corpuscles. In experiments, is brought into contact with one point of its convexity, the ball is at once drawn into the film as far as its equator, and is compelled to retain this position in opposition to the force of gravity. This is the exact converse of the case of the fixed bulb, in which the attraction is satisfied at the expense of the expansibility of the film, 2x2 564 : Presents. [ May 25, this case the film is brought to a focus upon the body, and not at a slight distance from it; so that either or both these modes might obtain with the corpuscle. In some cases the streak of solution is absent. The method of sealing, which leaves behind a portion of the film, is probably a necessity of every case of repair of continuity, with the exception of that of trans- mission of a foreign body through a film. In the case of the blood-corpuscle it would not appear that the capillary wall became applied over the surface of the corpuscle to any great extent, but that, having effected cohesion, it becomes easier for the capillary wall to give way and glide over the corpuscle than to be distended by it; and this is effected much slower than in the case of the factitious examples which I have placed before you. For capillarity to come into play, the presence on the exterior of the corpuscle of another and cohesively dissi- milar liquid to the liquor sanguinis is required ; and this we obtain by the outward passage, under the influence of osmosis, of the content-matter (heemoglobin) of the corpuscle; a magnified view of the relations present may be thus represented :— Capillary wall. = rs ee /_————— ====——~,, §Tensional surface of content-matter, Plasma. a ' Corpuscle wall. We may conclude in the appropriate words of Herbert Spencer :— “© We have in these colloids, of which organisms are mainly composed, just the required compromise between fluidity and solidity ; they cannot be re- duced to the unduly mobile conditions of liquid and gas, and yet they do not assume the unduly fixed condition usually characterizing solids; the absence of power to unite together in polar arrangement leaves their atoms with acertain freedom of relative movement, which makes them sensitive to small forces, and produces plasticity in the aggregates composed of them.’ — Principles of Biology, p. 23. The Society adjourned over the Long Vacation to Thursday, November 16th. Presents received May 25, 1871. Transactions. Bremen :—Naturwissenschaftliche Vereine. Abhandlungen. Band II. Heft 3. 8vo. Bremen 1871. The Society. Frankfurt a. M.:—Senckenbergischen Naturforschenden Gesellschaft. Abhandlungen. BandVII. Heft3,4. 4to. Hrankfurt1870. Bericht 1869-70. 8vo. Frankfurt 1870. 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[June 15, ‘Transactions (contenued), Christian Evidence Society. Lectures by the Bishop of Ely, C. Row, Stanley Leathes, F. C. Cook, and Dr. Rigg. 12mo. London 1871. The Earl of Harrowby, F.RS. East-India Association. Journal. Vol. V. No. 1. 8vo. London 1871. The Association. Linnean Society. Journal. Zoology. Vol. XI. No. 50,51. Botany. Vol. XI. No. 56. Proceedings, Session 1870-71. pp. i-xxviii. Syo. London 1871. The Society. London Institution. Journal. No. 1-6. 8vo. London 1871. The Institution. — London Mathematical Society. Proceedings. No. 32, 33,34. 8vo. London 1870-71. The Society. Meteorological Society. Proceedings. Vol. VY. No. 50-54. 8vo. Lon- don 1870-71. The Society. Odontological Society. Transactions. New Series. Vol. III. No. 5. 8vo. London 1871. The Society. Photographic Society. Photographic Journal. No, 217-225. 8vo. London 1870-71. The Society. Quekett Microscopical Club. Journal. No. 14, 8vo. London 1871. The Club. Royal Astronomical Society. Monthly Notices. 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London 1871. The Editor. ‘Zeitschrift fiir Chemie. June to Dec. 1870; Jan. to May 1871. 8vo. Lewzg. The Editors. Abbadie (A. d’) Sur la division décimale de Angle et du temps. 4to. . Paris 1870. The Author. Bastian (Dr.), F.R.S.. The Modes of Origin of Lowest Organisms. 12mo. London 1871. - The Author. Benson (L. 8.) A Dissertation on the Principles and Science of Geo- metry. 8vo. New York 1871. The Author. Brandt (J. F.) Ergiinzungen und Berichtigungen zur Naturgeschichte der Familie der Alciden. Ueber das Haarkleid des ausgestorbenen nordischen (bischelhaarigen) Nashorns (fhinoceros tichorhinus). Neue Untersuchungen iiber die in den Altaischen Hohlen aufgefun- denen Saugethierreste. 8vo. St. Pétersbourg 1869-70. The Author, Clausius (R.) Ueber die Anwendung einer von mir Aufgestellten mecha- nischen Gleichung auf die Bewegung eines materiellen Punctes um’ ein festes Anziehungscentrum und zweler materieller Puncte um einander. 12mo. Gottingen 1871. The Author. 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The Author. 572 7 Presents. Morgagni (J. B.) De Sedibus et Causis Morborum. 2 vols. in 1. fol. Venetits 1761. J. J. Bright, Esq. Prestel (M. A. F.) Der Boden der Ostfriesischen Halbinsel. 8vo. Emden 1870. The Author. Rivett-Carnac (H.) Cotton Exports from the Central Provinces and the Berars. fol. Bombay 1871. The Author. Sanderson (Dr. J. B.), F.R.S. Onthe Process of Inflammation. 8vo. Lon- don 1871. The Author. Settimanni (C.) Nouvelle Théorie des principaux éléments de la Lune et du Soleil. 4to. Mlorence 1871. The Author. Spratt (Capt. T. A. B.), F.R.S. Travels and Researches in Crete. 2 vols. 8vo. London 1865. The Author. Symons’s British Rainfall, 1870. 8vo. London 1871. G.J. Symons, Esq. Zantedeschi (F.) ‘Intorno all’ Elettro-chimica applicata all’ Industria e alle belle Arti. 8vo. Padova 1870. Delle burrasche dell’ Atmosfera solare e della possibile loro connessione colle burrasche dell’ Atmo- sfera terrestre. 8vo. Venezia 1870. The Author. ~ Portraits, Drawings, Original Letters, Anecdotes, and other Memorials of Joseph Priestley, LL.D., F.R.S., collected and arranged by the late James Yates, F.R.S., bound in blue morocco, with medals and Wedg- wood medallion portrait let into the cover. Mrs. Yates. Canton Papers belonging to the Royal Society, arranged with Prolego- mena, consisting of Notes, Portraits, and other illustrative matter, by James Yates, F.R.S., in two volumes. INDEX to VOL. XIX. AcxtonE, detection of, in methylated spirit, 440. Actinometrical observations made at Mus- _ goorie, 8; at Dehra and Mussoorie in 1869, 225. Airy (G. B.), remarks on the determination of a ship’s place at sea, 448. Aldehydes, deportment of certain, in pre- sence of mercuric oxide and alkaline metallic hydrate, 441. Allbutt (T.C.) on the effect of exercise upon the bodily temperature, 289. Altitude, on the determination of a ship’s place from observations of, 259. Analysis of the principal disturbances shown by the horizontal and vertical force magnetometers from 1859 to 1864, > D4. Angstrom (A. J.), elected foreign member, 97 ; his researches, 120. Animal electricity, researches in, 22. Anniversary Meeting, Nov. 30, 1870, 113. Annual meeting for election of Fellows, June 8, 1871, 494. Ansted (D. T.) on the temperature of the interior of the earth, as indicated by observations made during the construc- tion of the Great Tunnel through the Alps, 481. Approach caused by vibration, on, 35, 271. Arches, on the formation of some of the subaxial, in man, 380. Aromatic cyanates, on the, 108. Atlantic Ocean, continuous depth of 2000 fathoms in the, between the arctic and antarctic circles, 544. —,, observations on the currents of the, 552. Atmospheric pressure, on a new instru- ment for recording minute variations of, 491. Auditors, election of, 94. Aurora, observation of the spectrum of, io: Australia, on the fossil mammals of: Part IY. Dentition and mandible of Thylacoleo carnifer,95; Part V. Genus Nototherium, 494. Baffin’s Bay, currents in, 552. Bakerian Lecture, on the increase of elec- trical resistance in conductors with rise of temperature, and its application to the measure of ordinary and furnace temperature; also on a simple method of measuring electrical resistances, 443. Baltic Sea, observations on the currents, peer density, and salinity of, 36. Battery, a liquid thermometric, 341. Beams, on the theory of continuous, 56 ; remarks on, 68. Belavenetz (I.), magnetic observations made during a voyage to the North of Europe and the coasts of the Arctic Sea in the summer of 1870, 361. Bending moments of continuous beams, investigation of, 61. Berthelot (M.) on the change of pressure and volume produced by chemical com- bination, 445. Besant (W. H.) admitted, 494. Black Sea, observations on the currents, temperature, density, and salinity of, 536. Blood, experimental inquiry into the con- stitution of, 465. -corpuscles, on the physical principles concerned in the passage of, through the walls of the vessels, 556. Bordeaux wine, action of, on the human body, 73. British Museum, suggestions to lend du- plicate natural-history specimens, 123. Broughton (J.), chemical and physiologi- cal experiments on living Cinchonz, 20. Calamites of the coal-measures, on the organization of, 268. Callender (G. W.) admitted, 494. , on the formation of some of the sub- axial arches in man, 380, 574: Candidates for election, list of, March 2, 1871, 349. selected, list of, May 4, 1871, 450. Carpenter (W. B.) and Jeffreys (J. Gwyn), report on deep-sea reseaches carried on during the months of July, August and September 1870, in H.M. surveying- ship ‘ Porcupine,’ 146. Carruthers (W.) admitted, 494. ee (J.) on cyclides and sphero- quartics, eres of scientifie papers, notice of publication of vol. iv., 114. Cats, physiological action of codeia deri- vatives on, 510. Cayley (A.) on the problem of the in- and circumscribed triangle, 292. Ceratodus, a genus of gue ane de- scription of, 377. = Cetyl-alcohol, formation GR by a feel: reaction, 22, Chemical dynamics, on a law in, 498. Chemical intensity of total daylight, on the measurement of, at Catania during the total eclipse of Dec. 22, 1870, 511. Chromo-wulfenites, chemical properties of the, 455. Cinchone, chemical and physiological experiments on living, 20. Claret, action of, on the human body, ex- periments on, 73. Clark (F. Le Gros), some remarks on the mechanism of respiration, 486. Climate, physiological changes induced in the human economy by change of, 295. Coal-fields, extension of, beneath the newer formations, 222. Coal-measures, present dimensions of, due to succession of physical changes, 222. Codeia, action of chloride of zinc on, 71, , action of hydrobromic acid on, 371 ; ~ Part TI., 504. ——, on the physiological action of, 510. Colloid bodies, research on a new group ’ of, containing mercury, 431. Combined streams, on the mathematical theory of, 90. Comet L,, 187 1, on the spectrum of, 490. Continuous beams, on the theory of, 56. © Copley medal awarded to J. P. Joule, 123. Council, list of, 97, 128. Crace-Calvert (F.) on protoplasmic life, 468. , action of heat on protoplasmic life, 472. Crust of the earth, on the constitution of the solid, 223. Cyanates, on the aromatic, 108. Cyclides, on, 495. INDEX. Daniell’s battery, on a constant form of, 253. Dardanelles, observations on the canreits, temperature, and density of the, 532. Davidson (T.), Royal medal awarded to, 126. Daylight, on the measurement of the che- at intensity of, during an eclipse, 1 Dechenite, chemical properties of, 456. Deep-sea researches (1870), report on, 146. Dehra, actinometrical observations made at, 995, Density of sea-water, influence of rivers =< Oh). Des Cloizeaux (A. O.), Rumford medal pais: to, 126; notice of his researches, 127 Descloizite, chemical properties of; 456. Diaceto-mercuric hydrate, chemical teiptire of the, 437. Dielectrics, measurements of specific in< ductive capacity of, 285. ~ Diet, effect of, on the elimination of ni- trogen, 349. Dip, results of seven years’ observations of the, 368. Divers (E.) on the existence and forma- tion of salts of nitrous oxide, 425. : Donation Fund, account of sums granted from, 1870, 145. Dunean (P. M.) on the structure and affinities of Guynia annulata, Dune., with remarks upon the persistence of Paleozoic types of Madreporaria, 450, Dynamics, chemical, on a law in, 498. Earth, on the temperature of the interior of the, 481. Eclipse, Dec. 1870, observations of, at Oxford, 290. ——, total, on the measurement of the che- mical intensity of daylight during, 511. of the sun, Dec. 1870, notice of Go- vernment aid, 123. Election of Fellows, 494. Electrical resistance, on the increase of, in conductors with rise of temperature, 443; ona sunple method of measuring, 443. Electricity, a new method of obtaining, from mechanical force, 243. 2 , experiments on the discharge of, through rarefied media and the atmo- sphere, 236. Electrostatic ‘iditetion and the decom- position of water, on certain relations between, 243. Electrotonus, on, 26. Kosite, chemical characters of, 453. Equations, linear differential, on (No. III.), 14. Etheridge (R.) admitted, 494. “INDEX. ‘Kuler’s constant, on the calculation of, 514. Exercise, effect of, on the bodily tempera- ture, 289. , effect of, on the elimination of ni- trogen, 349, Fellows deceased, list of, 113; elected, 114; number of, 128. Financial statement, 129. Flow of a liquid, on the uniform, 286. ‘Fluoride of silver, on, 235. Forbes (J. D.), obituary notice of, i. Foster (M.) on the physiological action of codeia derivatives, 510. Frog, on the structure and development of the skull of the common, 246. Galton (F.), experiments in pangenesis, by breeding from rabbits of a pure variety, into whose circulation blood taken from other. varieties had previ- ously been largely transfused, 393. Garrod (A. H.) on the mutual relations of the apex cardiograph and the radial --sphygmograph trace, 318. German Ocean, observations on the cur- rents, temperature, density, and salinity of the, 540. Germinal vesicle, discovery of, x. Gibraltar, on the undercurrent in the strait of, 546. current, on the, 203. Gibson (J. C.) and Barclay (T.), measure- ments of specific inductive capacity of dielectrics, in the physical laboratory of the University of Glasgow, 285. Glacier-ice, on the structure and motion of, vi. Gladstone (J. H.) and Tribe (A.) on a law in chemical dynamics, 498. Glaisher (J. W. L.) on the calculation of Euler’s constant, 514. Gore (G.) on fluoride of silver: Part IT., 235. on the thermo-electric action of metals and liquids, 324. Government Grant, account of appropria- tion of, 1855-70, 135. Graves (J. T.), obituary notice of, xxvii. Giinther (A.), description of Ceratodus, a - genus of ganoid fishes, recently disco- vered in rivers of Queensland, Australia, 377. Guthrie (F.) admitted, 494. on approach caused by vibration, 35. Guynia annulata, on the structure and affinities of, 450. Heat, action of, on protoplasmic life, 472. , effect of, on electric and thermal conductivity, vii. 57D Heat, on the radiation of, from the moon, 9 Hennessey (J. H.), actinometrical obser- vations made at Dehra and Mussoorie in India, October and November 1869, in a letter to the President, 225. — on the atmospheric lines of the solar spectrum, in a letter to the Presi- dent, 1. Heppel (J. M.) on the theory of conti- nuous beams, 56. Heppel’s theory of continuous beams, re- marks on, 68 Hind (J. R.), note on the circumstances of the transits of Venus over the sun’s disk in the years 2004 and 2012, 428. Hofmann (A. W.) on the aromatic cya- nates, 108. Horizontal force, results of seven years’ observations of, 368. Huggins (W.), note on the spectrum of Uranus and the spectrum of Comet L.,, 1871, 488. on a registering spectroscope, 317. Hull (E.) on the extension of the coal- fields beneath the newer formations of England ; and the succession of phy- sical changes whereby the coal-measures have been reduced to their present dimensions, 222. Hydrobromic acid, action of, on codeia, 3871; Part II., 504. Hydrocarbons, researches on: No. VL, 20; No. VIL., 487. Ice-fields, variations of, on coast of Green- land, 118. Internal resistance of a multiple battery, measurement of, by adjusting the gal- vanometer to zero, 252. Tyory’s discussion of Jacobi’s theorem, on, Jacobi’s theorem respecting the relative equilibrium of a revolving ellipsoid of fluid, on, 42. Joule (J. P.), Copley medal awarded to, 123. Ketones, research on certain members of the series of fatty, 431. Kew Observatory, records of the magnetic observations at the: No. LY., 524, Lead, on the molybdates and vanadates of, 451 Leadhills, on a new mineral from, 451. Lepidodendra, 500. Le Sueur (A.), observations with the great Melbourne telescope, in a letter to Prof, Stokes, 18. 576 Life, on protoplasmic, 468 ; action of heat on, 472 Light, suppression of chemical action of, during an eclipse, 518. Linear differential equations, on: No. III., 14; No. IV., 281; No. V., 526. Liquid, on the uniform flow of a, 286. ee on the thermo-electric action of, Loewy (B.), résumé of two papers on sun- spots :—“ On the form of the sun-spot curve,” by Prof. Wolf; and “On the connexion of sun-spots with planetary configuration,” by M. Fritz, 392. Lowe (Right Hon. R.) elected, 481 ; ‘ad- mitted, 494. Luminous cloud in a Geissler’s tube, on the nature of, 239. iy Madreporaria, remarks on the persistence of palzozoic types of, 450. Magnetic observations made during a voyage to the coasts of the Arctic Sea, 1870, 361. Magnetometers, disturbances shown by the horizontal and vertical force, at Kew, 524, Mance (H.), method of measuring the re- sistance of a conductor or of a battery, or of a telegraph-line influenced by unknown earth-currents, from a single deflection of a galyanometer of unknown resistance, 248. , measurement of the internal resist- ance of a multiple battery by adjusting the galvanometer to zero, 252. Marcet (W.), an experimental inquiry into the constitution of blood, and the nutri- tion of muscular tissue, 465. Maskelyne (N. 8.) on the mineral consti- tuents of meteorites, 266. Matthiessen (A.) and Burnside (W.), re- searches into the chemical constitution of the opium bases: Part IV. On the action of chloride of zinc on codeia, 71, 94. Mechanism of respiration, remarks on, 486. Mediterranean, temperature of the, 531. water, temperature and composition of, 193. Metals, on the thermo-electric action of, 324. Meteorites, on the mineral constituents of, 266. Miller (W. A.), notice of decease of, 114 ; obituary notice of, xix. Miller (W. H.), Royal medal awarded to, 124; notice of his researches, 125, Molybdates of lead, on the, 451. Moncrieff (A.) admitted, 494. Moon, on the radiation of heat from the, 9. | INDEX. Moseley (H.) on the uniform flow of a liquid, 286, Muscle, behaviour of, under action of in- verse and direct currents, 24. Muscular tissue, experimental inquiry into the nutrition of, 465. Mussoorie, actinometrical observations made at, 225; spectrum observations made at, 2. Newton (A.) admitted, 246. Nitrogen, further experiments on the effect of diet and exercise on the elimination of, 349. Nitrous oxide, on the existence and for- mation of salts of, 425. Noble (A.) admitted, 94. Norris (R.) on the physical principles concerned in the passage of blood-cor- puscles through the walls of the vessels, 556. North-German polar expedition, notice of, 116. Nototherium, 494. Obituary notices of deceased Fellows :— James David Forbes, 1. Johann Evangelista Purkinje, ix, Sir James Clarke, xiii. : William Allen Miller, xix. John Thomas Graves, xxvil. Ocean, on the undercurrent theory of, as propounded by recent explorers, 528. Oceanic circulation, general, 213. Olefines, on the production of the, from paraffin, 370. Opium alkaloids, contributions to the history of: Part I., 371; Part IT., 504. bases, researches into the constitution of the: Part IV., 71, 94. Orcin, contributions to the history of: No. I., 410. Orcins, nitro-substitution compounds of the, 410. Orion, observations on the nebula in, 19. Osborn (8.) admitted, 94. Owen (R.) on the fossil mammals of Australia: Part IY. Dentition and mandible of Thylacoleo carnifex, with remarks on the argument for its herbi- vority, 95; Part V. Genus Nototherium, 494. Pangenesis, experiments in, 393. Paraffin, preliminary notice on the pro- duction of the olefines from, 370. Parker (W. K.) on the structure and de- velopment of the skull of the common frog (ana temporaria), 246. Parkes (E. A.), further experiments on the effect of diet and exercise on the elimi- nation of nitrogen, 349, INDEX, Parkes (H. A.) and Wollowicz (Count C.), experiments on the action of red Bor- deaux wine (claret) on the human body, 73, 99. Peirce (B.) admitted, 235. Pendulum observations in connexion with the Great Trigonometrical Survey of India, 97, 115. Perry (8. J.), results of seven years’ obser- vations of the dip and horizontal force at Stonyhurst College Observatory, from April 1863 to March 1870, 368. Phillips (J.), observations of the eclipse at Oxford, December 22, 1870, 290. Plants, fossil, of the coal-measures (Part II.), on the organization of, 500. Plateau (J. A. F.), elected foreign mem- ber, 97; his researches, 119. Polarization of light, experiments on the successive, 381. of metallic surfaces in aqueous solu- tions, 243. Polarizing-apparatus, description of anew, 381. ‘Porcupine’ surveying-ship, notice of, 123 ; deep-sea researches in, 146 ; equip- ment of, 150; first cruise, 152; second cruise, 162; general results, 185. Pratt (Ven. H.) on the constitution of the solid crust of the earth, 223. Presents, list of, 29, 131, 273, 345, 418, A477, 564. Pressure, on the change of, produced by chemical combination, 445. Protoplasmice life, on, 468; action of heat on, 472. Pulse, action of food and wine on the, 76. Purkinje (J. H.), obituary notice of, ix. Quain (R.) admitted, 494. Rabbits, experiments of transfusion with, 393 , physiological action of codeia deri- vatives on, 510. Radcliffe (C. B.), researches in animal electricity, 22. Rankine (W. J. M.), remarks on Mr. Heppel’s theory of continuous beams, 68. —-, on the mathematical theory of com- bined streams, 90, 95. Rattray (A.) on some of the more impor- tant physiological changes induced in the human economy by change of cli- mate, as from temperate to tropical, and the reverse, 295. Reed (H. J.) on the unequal distribution of weight and support in ships, and its effects in still water, in waves, and in exceptional positions on shore, 292. VOL, XIX. 577 Resistance of a conductor, battery, or telegraph-line, on a method of measu- ring the, from a single deflection of a galvanometer, 248. Resonance, on the theory of, 106. Respiration, some remarks on the mecha- nism of, 486. Reynolds (J. H.), research on a new group of colloid bodies containing mercury, and certain members of the series of fatty ketones, 431. Roscoe (H. HE.) and Thorpe (T. E.) on the measurement of the chemical intensity of total daylight made at Catania du- ring the total eclipse of Dec. 22, 1870, 511. Rosse (Harl of) on the radiation of heat from the moon: No. IT., 9. Royal Medal awarded to W. H. Miller, 124; to T. Davidson, 126. Rumford Medal awarded to A. des Cloi- zeaux, 126. Russell (W. H. L.) on linear differential equations: No. III., 14; No. IV., 281; No. V., 526. Sabine (Sir E.), intimation of resigning the Presidency, 127. / , records of the magnetic observations at the Kew Observatory: No. IV. Ana- lysis of the principal disturbances shown by the horizontal and vertical force magnetometers of the Kew Observatory from 1859 to 1864, 524. Salt-meat diet, effect of, on the weight of the human body, 302. Salts of nitrous oxide, on the existence and formation of, 425. Sea, on the surface-temperature of the, 185; temperature at different depths, 188. of Marmora, observations on the currents, temperature, and density of the, 534. Sea-water, density of, 191. Schorlemmer (C.), formation of cetyl- alcohol by a singular reaction, 22. , researches on the hydrocarbons of the series C”H. No. VI., 20; No. 2n+2" VIL., 487. Schrauf (A.) on the molybdates and vana- dates of lead, and on a new mineral from Leadhills, 451. Ships, on the unequal distribution of weight and support in, 292. Ship’s place, determination of, from ob- servations of altitude, 259; remarks on, 448, , amended rule for working out Sumner’s method of finding a, 524. Siemens (C. W.), Bakerian Lecture, on the increase of electrical resistance in DY 578 conductors with rise of temperature, and its application to the measure of ordi- nary and furnace temperatures ; also on a simple method of measuring electrical resistances, 443. Sigillarie, 500. Silver, on fluoride of (Part IT.), 235. Skull of the frog, structure and develop- ment of the, 246, Solar rays, effect of, on cinchona-bark, 20. spectrum, on the atmospheric lines of the, 1. Spectroscope,,on a registering, 317. Spectrum, Angstrdm’s observations of, 121. of the aurora, 19. — of Uranus, note on, 488; of Comet I., 1871, 490. Sphero-quartics, on, 495. Sphygmograph trace, on the mutual rela- tions of the apex cardiograph and the radial, 318. Spratt (T. A. B.) on the undercurrent theory of the ocean, as propounded by recent explorers, 528. Stenhouse (J.), contributions to the his- tory of orcin: No. I. Nitro-substitution compounds of the orcins, 410. Stone (EH. J.) on an approximately decen- nial variation of the temperature at the observatory at the Cape of Good Hope between the years 1841 and 1870, viewed in connexion with the variation of the solar spots, 389. Stonyhurst, results of seven years’ observa- tions of the dip and horizontal force at, 368. Strutt (J. W.) on the theory of resonance, 106. Sun-spot curve, on the form of the, 392. Sun-spots, on the connexion of, with plane- tary configuration, 592. , résumé of two papers on, 892. ——, variation of, viewed in connexion with a decennial variation of tempera- ture, 389. Sutherland (Duke of) elected, 97; admitted, 222. Telescope, observations with the great Melbourne, 18. Temperate climate, effect of, on the weight, 305. Temperature, bodily, on the effect of ex- ercise on the, 289. , decennial variation of, at the Cape of Good Hope, viewed in connexion with the variation of the solar spots, 389. , on the measurement of, by electrical resistance, 443. INDEX. Temperature, as indicated by observations made in the great tunnel through the Alps, 481. Thermo-electric action of metals and li- quids, on the, 324. Thomas (E.) admitted, 494. Thomson (Sir W.), amended rule for working out Sumner’s method of finding a ship’s place, 524. , modification of Wheatstone’s bridge to find the resistance of a galvanometer- coil from a single deflection of its own needle, 253. on a constant form of Daniell’s bat- tery, 253. on the determination of a ship’s place from observations of altitude, 259. — on approach caused by vibration, a letter to F. Guthrie, 271. Thorpe (f. E) and Young (J.), prelimi- nary notice on the production of the olefines from paraffin by distillation under pressure, 370. Thylacoleo carnifex, dentition and mandi- ble of, 95. Todhunter (I.) on Jacobi’s theorem re- specting the relative equilibrium of a revolving ellipsoid of fluid, and on Ivory’s discussion of the theorem, 42. Transits of Venus in the years 2004 and 2012, 423. Triangle, on the problem of the in- and circumscribed, 292. Trinitro-orcinic acid, 412. Tropical climate, influence of, on the kidneys and skin, 295; on the weight and strength, 300. Tunnel through the Alps, experiments on temperature made in the, 481. Uranus, on the spectrum of, 488. Vanadates of lead, on the, 451. Vanadinite, chemical properties of, 456. Tarley (C. F.), polarization of metallic surfaces in aqueous solutions, a new method of obtaining electricity from mechanical force, and certain relations between electrostatic induction and the decomposition of water, 243. , some experiments on the discharge of electricity through rarefied media and the atmosphere, 236. Venus, on the circumstances of the tran- sits of, over the sun’s disk in the years — 2004 and 2012, 423. Verdon (G. F.) admitted, 94. Vibration, on approach caused by, 35, 271. Vice-presidents appointed, 145, Volume, on the change of, produced by chemical combination, 445, INDEX. Walden (Viscount) admitted, 494. Walker (Col. J. T.) admitted, 245. , communication from the Secretary of State for India relative to pendulum- observations now in progress in India in connexion with the Great Trigonome- trical Survey under the super intendence of, 97. ——, report on pendulum-observations in | India, 98, 115. Wheatstone (Sir C.), experiments on the successive polarization of light, with the description of a new polarizing-appara- tus, 381. Wheatstone’s bridge, modification of, to find the resistance of a galvanometer- coil a a single deflection of its own needle, 253. Whitehouse (W.) on a new instrument END OF TRE A Lo) kip Gear BA ea Ds 9 Sh 6 = NE AU AV OIG (O15: 579 for recording minute variations of at- mospheric pressure, 491. Williamson (W. C.) on the organization of the Calamites of the coal-measures, 268. on the organization of the fossil plants of the coal-measures: Part IT. Lepidodendra and Sigillarie, 500. Wine, effect of, on bodily temperature, 79. Wood (J.) admitted, 494. Wrieht (C. R. A.), contributions to the history of the opium alkaloids: Part TI. On the action of hydrobromie acid on codeia, 371; Part II., 504. Zine, chloride of, on the action of, on co- deia, 71, 94. Zodiacal light, observations on tke, made et Mussoorie, 8. TEENTH VOLUME, AND FRANCTS, RED LION CCURT, FLEET STRELT, OBITUARY NOTICES OF FELLOWS DECEASED*. James Davip Forsest was the youngest son of Sir William Forbes of Pitsligo, who was descended from the ancient family of the Forbes of Monymusk, on the banks of the Don, and was head of the well-known bank- ing-house long established in the Parliament Square of Edinburgh. The mother of James Forbes was the only child and heiress of John Belches, afterwards Sir John Stewart, a cadet of the old house of Invermay. The early death of Lady Forbes, while her youngest son was a child scarce two years old, cast a sobering shade over his early years, and indeed coloured his whole life and character. His father idolized the child, as the last legacy of her whom he had lost. He retired from Edinburgh, and lived a secluded life, surrounded by his young family, in his country place of Colinton. There were spent James Forbes’s childhood and boyhood. The teaching he got was of the most private, even desultory kind. Fear for the boy’s health made his father nervously anxious lest he should overwork himself. So his education was left entirely to his sisters’ governess, and to occasional lessons from the neighbouring village schoolmaster, a worthy man, to whom his distinguished pupil remained ever afterwards sincerely attached. But though lessons were easy, his mind was active, and by his twelfth year the natural bias towards physical knowledge was manifesting itself. Already his head was busy with mechanical contrivances,—a new velocipedometer, an anemometer, a metal quadrant made by his own hands for astronomical purposes. At the same time he was devouring every scientific book he could lay hands on, from the ‘Nautical Almanac’ to Woodhouse’s ‘ Astronomy.’ But all this devotion to science was kept strictly secret; he laboured at it in private, and said nothing, for his father would not have smiled on such pursuits. He would have objected to them both as too serious a tax on the young brain, and also as likely to turn him from the dry studies of the bar, for which he was destined. His own wish was to take orders in the English Church, to which he was strongly attached ; but from this aim he was, not without reluctance, withdrawn by his father’s expressed wish that he should study for the Scottish bar. This accordingly, from his fifteenth to his twenty-first year, was his ostensible purpose, but his heart was all the while turning secretly aside to the for- * Note to a passage in the Biography of M. Foucault, Proceedings of the Royal Society, vol. xvii. It appears from a notice in the Report of the British Association for the Promotion of Science for 1843, that Dr. Joule had made an experiment demonstrating the conver- sion of work into heat, very similar to the experiment by M. Foucault described at the end of page lxxxiii. t This notice of Professor Forbes, except what more especially refers to his scientific work, has been taken, with abridgement, but without other alteration in matter or lan- guage, from an inaugural address delivered by his distinguished successor, Principal Shairp, at the opening of the Academical Session of the United College, St. Andrew’s, in 1869. ; VOL, XIX. a il bidden paths of science. When he was only sixteen he began to keep a record, entitled ‘‘ Ideas of Inventions ;’’ because, as he expressed it, so many more ideas, chiefly mechanical, occurred to him than he could pos- sibly execute; and, in order to remember these, he ‘‘ resolved to write them down, taking most special care to distinguish between what were ori- ginal and the parts which were borrowed.’ About the same time he began a journal of personal observations in astronomy, which he continued, with scarce an interruption, for seven years. He then also began to keep a meteorological journal, in which he recorded all his observations on the temperature and state of the atmosphere, with speculations as to their causes. The two last, especially, were continued for years. ‘These were’ his real and earliest educators in science. By these he trained himself to be the patient and accurate observer which he ultimately became. Thus entirely home-trained, and, indeed, self-educated, young Forbes entered Edinburgh University in Session 1825-26, and joined the Classes of Latin and Chemistry. About the close of his first year at College he entered. on another phase of his self-education, which was destined to have important results. He commenced an anonymous correspondence on scientific matters with the late Sir David Brewster. The lad of seventeen wrote to the then renowned man of science, offering him for insertion in his well-known ‘ Phi- losophical Journal’ a paper containing an attempt to account for the appa- rently infinite number of the stars. The paper was not only inserted, but the following words were annexed to it: “ We should be glad to hear again from the author of this article, and, if possible, learn his address.” The first part of this request was readily complied with. For several years hardly a Number of the journal appeared without some paper either of original observation, experiment, or cautious speculation from the young votary of science. ‘The latter part of the request he was more slow to meet ; all the communications still bore the original signature, or “‘A’’—a disguise which the author’s modesty induced him to assume, and which Sir David tried to pierce for some years in vain. Those who are best versed in these subjects will, I believe, most appreciate the natural insight, careful toil, and patient observation embodied in those papers, written at seventeen, with none to help or consult with, indeed, in the utmost secrecy. Towards the end of 1826 the young student’s College course was interrupted (but his philoso- phical correspondence was not) by a year spent in Italy with his father and family. With his passion for science in no degree abated, he entered into all that Italy contains to feed the imaginative and historic mind, almost as fully as if he had been exclusively a scholar or man of letters—so early appeared that fine blending of literary taste with scientific exactness which in after years lent to his lectures and his writings so great a charm. The ‘ Philosophical Journal’ contained some fruits of his Italian experiences, in what Sir David styles ‘‘ A’s very excellent set of observations,’ made at Rome, on the climate of Naples, and on the phenomena of Mount Vesu- vius. These three papers appearing in successive Numbers of the Journal, il called forth much attention from scientific men. On his return home to Colinton, in the autumn of 1827, his diary records that he is pleased ‘‘ to see Brewster’s journal, and read the articles of mine he inserted in October last on the apparent number of the stars, the heats and colds of last year, and elements of the lunar eclipse, together with all the other papers which I have sent, inserted, or favourably noticed.” In the correspondence with Brewster, the disguise of A was preserved to the close of 1828. Many and curious were the attempts Sir David made to pierce behind the mask and see the real face of his unknown contributor. In one of his letters he says :—‘‘ We who have begun our downward course look anxiously for some rising stars; but, excepting yourself and Mr. F., I know of no young men who are likely to extend the boundaries of science.”” Who was Mr. F.? Was he the same as the unknown A? When at length the mask was withdrawn, the welcome which the elder philosopher gives _ to his younger fellow-labourer is highly characteristic. He expresses his joy ‘‘ that Scotland possesses one young man capable of pursuing science with the ardour and talent of A, and that he belonged to a family for which he had so much esteem and affection.’” He then goes on to advise him to allow no professional duties to turn him from science; he would find in it a solace and delight amid the bustle and vexations of life. Though thus early launched into original inquiries, James Forbes was still only a Student of Arts in Edinburgh University. The excitement of young and successful authorship seems never for a moment to have turned his head, or to have made him bate one jot the patient industry by which only college classes can be turned to account. In the Moral Philosophy Class, which he attended after returning from the Continent, we find him preparing with great labour an essay of sixty large quarto pages for Pro- fessor Wilson. The essay was on the influence and advantages of the study of astronomy on the mind, and it was accompanied by scientifie illustrations and notes. This and other essays of the young physicist so far commended themselves to the Professor of Ethics, that at the close of the Session he made him Medalist in the Class, and ever afterwards re- ceived him to intimate friendship. The month before James Forbes entered the Class of Natural Philosophy an event happened which deeply impressed him. His father was removed by death, and this was soon to be followed by the breaking of the old home at Colinton House. This bereavement formed a turning-point in his life, and deepened his already religious character. Solemnized, yet braced, he entered on the Natural Philosophy Class, then taught by the celebrated Sir John Leslie, in his later years. In the subjects of that Class lay his own specialty, but he had never received one word of mathematical instruction from any one, all his mathematics were entirely self-acquired. Yet, not- withstanding this disadvantage, in the competitions with students who had passed through a regular Mathematical Course he held the first place, and closed the Session by easily bearing off the highest honours. While he was a 2 iV a Student in the Natural Philosophy Class he had the honour of being pro- posed by Sir David Brewster as a Member of the Royal Society of Edin- burgh before he had reached his twentieth birthday. Though his College course may be said to have been now completed, he took yet another Session, attending Sir John Leslie’s Class, and the Che- mistry Class of Dr. Hope each for the second time, and combining with these two the study of the Law. At the close of his College life, in April 1830, he looks back on it, in his diary, ‘‘ with peculiar satisfaction, as com- prising the happiest period of his life.” That summer (1830) he passed his Law trials, and put on his advocate’s gown, but never wore it. To his great joy, having obtained the full concurrence of his family and friends, he cast law for ever behind him, and, content with a small competence, gave himself unreservedly to science. This resolution was not taken hurriedly. But his mind once made up never faltered. At the beginning of next winter he says :—‘‘I now enter on the delightful and engrossing studies, which have now, blessed be God, become my principal and legiti- mate object, untrammelled by jarring occupations and conscientious scruples. He then gave himself to closer study of the higher mathematics, and at the same time began those experiments on heat which were afterwards to result in one of his best scientific achievements. A hint of his future destiny was at this time given him. He had jhappened to go to hear Sir John Leslie’s opening lecture in that Professor’s last Session but one, 1830-31. At the close of the lecture Sir John, who had never before admitted his promising Student to any special intimacy, sent for him, and, after asking him about his own studies, told him that when he (Sir John) proposed going to the East last summer, he had thought of getting him (James Forbes) to officiate for him, but was afraid the public might think him too young. He then broke off abruptly. In exactly two years from this time young Mr. Forbes, who had gone to the Continent on a long scien- tific tour, was recalled by the news of Sir John Leslie’s death, and that his friends in Scotland had given in his name as a Candidate for the vacant Chair. Then ensued a contest, not the least memorable of those many contests of the same kind by which Edinburgh has made itself conspi- cuous. Two things made this one especially warm, and even painful. By one of those strange turns in men’s destiny, Mr. Forbes’s chief opponent was his friend and patron, Sir David Brewster, now almost a veteran in the army of science. Political feeling, too, wasadded. It was the era of the Reform Bill, and party spirit, then running high in Scotland, as else- where, entered as an element of the contest even more than it usually does. Mr. Forbes, though only twenty-three, was elected by a very deci- sive majority ; and, however it may have appeared at the time, the result, we know, justified the wisdom of the choice. It is pleasing to be assured that, whatever passing feeling the contest may have awakened, the old intimacy was soon renewed, and the friendship so honourable to both these distinguished men continued unimpaired till the close of their lives. Vv He thus entered on a Professorate of seven-and-twenty years, carried on with an energy and success rarely equalled, never surpassed. He began to teach the Natural Philosophy Class in Session 1833-34, when he was only four-aud-twenty, yet from the very first he rivetted the attention of one of the largest and most distinguished classes of students that Edinburgh University ever contained. One great feature of his teaching, as I have always understood, was that while it stimulated the powers and won the admiration of his most scientific listeners, he yet made himself attractive to all students who were intelligent, though less highly gifted. In these lectures the whole range of Natural Philosophy was gone through, and the laborions and well-sustained study required for the due performance of his professorial work had doubtless prepared him for the task, which he successfully accomplished, of writing the well-known “ Dis- sertation on the Progress of Mathematical and Physical Science, principally from 1775 to 1850,” which was published in the last edition of the ‘ Ency- clopeedia Britannica.’ Meanwhile, however, Professor Forbes was indefa- tigable in original investigation, for which he had so early shown an apti- tude; and the separate titles of his contributions to Transactions of Societies and Scientific Journals, as given in the Royal Society’s ‘ Catalogue of Scientific Papers,’ amounted in 1863 to one hundred and eighteen. These embrace various subjects belonging to Physics, Meteorology, Geo- logy, and Physical Geography. The most important of his earlier experi- mental investigations was that in which he succeeded in demonstrating the polarization of heat. Melloni had been pursuing an inquiry in the same direction, but had failed to obtain the result he was in quest of. Professor Forbes was more fortunate. The steps of his investigation are thus stated by himself in the dissertation above referred to. He says :—‘‘ I have just referred to my own early experiments on the subject (which were likewise inconclusive), in order to explain that it was natural, on hearing of the application of the thermo-multiplier to measure radiant heat, that I should wish to repeat them with the new instrument. This I did in 1834. I first succeeded in proving the polarization of heat by tourmaline (which Melloni had announced did not take place), next by transmission through a bundle of very thin mica plates, inclined to the transmitted ray, and afterwards by reflexion from the multiplied surfaces of a pile of thin mica plates placed at the polarizing angle. I next succeeded in showing that polarized heat is subject to the same modifications which doubly-refracting crystallized bodies impress upon light, by suffering a beam of heat (even when quite obscure), after being polarized by transmission, to pass through a depolarizing plate of mica, the heat traversing a second mica bundle before it was received on the pile. As the plate of mica used for depolarization was made to rotate (in its own plane), the amount of heat shown by the galvanometer was found to fluctuate just as the amount of light received by the eye under similar circumstances would have done. This experiment, which, with the others just mentioned, was soon re- peated and confirmed by other observers, still remains the only one proving VI the double refraction of heat unaccompanied by light; and, though some- what indirect, it will hardly be regarded by competent judges as otherwise than conclusive. Iceland spar and other doubly-refracting substances absorb invisible heat too rapidly to be used for affecting directly the sepa- ration of the rays, which requires a very considerable thickness of the erystal. I also succeeded in repeating Fresnel’s experiment of producing circular polarization by two internal reflections. The substance used was, of course, rock-salt.”’ For these researches the Royal Society awarded to their author the Rumford Medal, in 1838. Taken in conjunction with the experiments of Melloni on the absorption, &c. of radiant heat, they afforded the conclusive proof of the cdentity of thermal and luminous radiations,—a fact of the very greatest consequence to the further progress of one of the most fascmating branches of physical science. In 1842 Professor Forbes communicated to the Royal Society a paper **On the Transparency of the Atmosphere, and the Law of Extinction of the Solar Rays in passing through it,’ which was adopted as the Bakerian Lecture for that year, and for which in 1843 he received a Royal Medal. Another prominent work of Forbes is that long series of observations on the Nature and Motion of Glaciers, which he pursued with intense applica- tion, and, as there is too good reason to believe, to the serious injury of his health. He had spent several vacations on the Continent, and had wan- dered over the mountains of Switzerland and Savoy, studying the Geology and Physical Geography of those regions; but he specially devoted the summers of 1842-44 and 1846 to the exploration of the glaciers of the Alps. Into this pursuit he threw an enthusiasm and concentration of energy which few men are capable of. In 1843 appeared his well-known work, ‘ Travels in the Alps,’ in which he blends interesting descriptions of scenery with scientific observations and reasonings ; and the fruits of his earlier labours on the glaciers are there given. Shortly before this he commenced the interesting series of sixteen “‘ Letters on Glaciers” published in the ‘ Edinburgh New Philosophical Journal’ from 1842 to 1851, which contain the results of his continued study; and he also set forth and discussed his views on the constitution and motion of glaciers, iu an elabo- rate Memoir published in the Philosophical Transactions for 1846, en- titled ‘‘ Illustrations of the Viscous Theory of Glacier Motion.” Not contented to limit his observations to Switzerland and Savoy, he in 1851 made an excursion to Norway to study the glacier phenomena of that country, and gave an account of his work in ‘ The Glaciers of Norway * visited in 1851,’ which was published in 1853. Professor Forbes looked on the progressive motion of a glacier as com- parable to that of a plastic mass, moulding and adapting itself to the varia- tions in the width and depth of its channel and the inclination of its bed, and moving faster in the middle than at the sides, as would happen with such a yielding substance. A view substantially similar had been previously pro- mulgated by Bordier in 1773, the contemporary of De Saussure, and more ‘YVil recently by M. Rendu, then Canon, afterwards Bishop of Annecy; but to Forbes belongs certainly the merit of proving its general truth by careful and prolonged experimental measurements of the rate of progression of glaciers at different parts. But whilst it is plain that the ice of a moving glacier behaves in the gross like a plastic substance, there has been a ques- tion by what intestine changes or motions of its particles its change of figure is brought about or accompanied ; and later inquirers maintain that the ice yields by breaking up into minute fragments, which speedily reunite by partial melting and regelation, thus permitting of change of form in the mass. The ribboned or veined'structure of glacier ice, which had been but little attended to by previous writers, was carefully studied by Forbes. Having seen that the velocity of movement increases from the sides to the middle of the glacier, he ascribed the production of the ribboned structure o “ differential motion”’ between adjacent laminar sections of its substance, a process which has since been termed ‘shearing.’ Others have com- pared the phenomenon to the lamination of slaty rocks now very generally regarded as caused by pressure in a direction perpendicular to the planes of lamination. But while there may be difference of opinion as to the physical explana- tion of the observed phenomena, there can be no question of Forbes’s signal merit in connexion with the scientific history of glaciers ; and it is pleasing to know that it was generously acknowledged in his lifetime by a distinguished rival in the same field, who thus speaks of him*:—* The more his labours are compared with those of other observers, the more prominently does his comparative intellectual magnitude come forward. The speaker would not content himself with saying that the book of Prof. Forbes was the best book which had been written on the subject. The qualities of mind, and the physical culture invested in that excellent work, were such as to make it, in the estimation of the physical BEES 0 at least, outweigh all other books upon the subject taken together.” While Switrerland was the main region of Forbes’s explorations; he did not neglect his own land. In the summer of 1845 he traversed the rugged hills of Skye, and proved that the bare scarps of the Cuchullius had been ground down by the same kind of glaciers as those which are now wearing down the gorges of the Alps. The last important scientific labour he was permitted to undertake was on the subject of thermal conductivity. He was the first to point out— and this at a very early period of his career—the fact that the conducting- powers of the metals for electricity are approximately proportional to their conducting-powers for heat. Now, heat diminishes materially the electric conducting-power—does it also affect the thermal conductivity? Forbes showed that (at least in the case of iron, the only metal his failing health left him strength to examine) the conductivity for heat diminishes as the a al increases. Another result of the same investigation, and one * Report of a Lecture delivered by Professor Tyndall at the Royal Institution, June 4, 1858, Viil of great interest and importance in modern science, is his determination (the earliest of any real value) of the absolute conductivity of a substance, i.e. how much heat passes per second per unit of surface through an iron plate of given thickness, whose faces are maintained at constant given temperatures. As a proof of the value attached by scientific men to these ingenious experiments, it is only necessary to mention that the British Association has given a grant for their repetition with the best attainable instrumental means, and for their extension to other substances than that to which Forbes was obliged to confine himself. But on his more active work an arrest was soon to be laid. In De- cember 1851 he was prostrated by a severe hemorrhage in the lungs, occasioned, it was thought, in part by exposure on the Alps, in part by too close application while prosecuting further experiments on heat. For two Sessions and a half he was entirely laid aside from work. In the winter of 1854 he resumed his duties, but daily lecturing was a heavy burden on his now enfeebled strength. As for exploration or continuous experimenting, all that was ended. “Though he could not leave Edinburgh without some natural pangs, yet,” continues Principal Shairp, “it was no doubt a relief to him when _he was called to assume the Principalship of this College [St. Salvador and St. Leonard’s United College, St. Andrew’s | in the beginning of Session 1859-60. The office fitted in better to his state of health, because it relieved him from the necessity of giving daily lectures, and set him more free to do his work at the hours and in the way that suited him. He was, however, far from regarding it as a sinecure, as some speak. Our late Principal was not the man to regard any post of trust as a sinecure. He came among us, no doubt, with diminished strength. But illness had not abated his mental energy. Few men felt more the appeal which the past history and present aspect of this city makes to the imagination. But though much captivated with this, he found on his arrival enough of hard matter-of-fact work ready to his hand, and into it he threw himself vigorously.” ‘‘Those who were comparatively strangers to our late Principal ob- served in him a certain antique formality and reserve which they sometimes mistook for coldness. They little knew how gentle and affectionate a heart lay under that exterior— what longing for sympathy, what apprecia- tion of confidence and frankness in others. His thoroughness in all work, his painstaking in the most ordinary college business, his patience in getting to the bottom of every minutest detail—as great, indeed, as if it had been a link in some grave discovery—these are things which only his colleagues can know.” ‘His last public act, I believe, was to preside at the laying of the foundation-stone of the new College Hall Building in 1867. A few days after, he left St. Andrew’s not to return. The sequel in its outward de- tails (that winter abroad, the return to Clifton, and the close) would be too painful to dwell on, But while his body was reduced to the last stage of iX weakness, his mind remained self-controlled, unclouded, and peaceful to the end. He departed on the last day of the departing year (1868), up- held by humble faith in Him to whom long since he had committed him- self.” Professor Forbes was a Vice-President of the Royal Society of Edin- burgh, and a Corresponding Member of the French Institute. His elec- tion into the Royal Society is dated June 7, 1832. JoHANN EvANGELISTA PuRKINSE was born in the town of Libochowitz, near Leitmeritz, in Bohemia, on the 17th of December, 1787. He obtained the first rudiments of education in the school of Libochowitz. He then went to Nicholsburg in Moravia, where he passed through the normal school and Gymnasium with credit, and entered the Order of the Piarists with the in- tention of becoming a teacher. After anoviciate of one year at Kaltwasser in Moravia, he was sent to Strdznic in Hungary as teacher in the Gymna- sium of that place. In 1805 he began to study French and Italian, and also the language and literature of Bohemia. In the following year, while officiating as teacher in the normal school at Leutomischlin in Bohemia, he turned his attention to the writings of the German philosophers, and espe- cially to those of Fichte. These pursuits opened out to him the prospect of a higher intellectual culture, which he felt to be within his reach. He accordingly quitted the school and became a student in the University of Prague, and supported himself by taking pupils. After some hesitation, he adopted the career of medicine. For two years he pursued his studies in the Anatomical Institute under Dr. Ilg, and for two more in the surgical division of the hospital under Dr. Fritz, by whom he was greatly esteemed. During this time he derived the means of living from the family of Baron Hildeprandt, to whose son he had been tutor. In 1818 he graduated as M.D., the title of his inaugural dissertation being, ‘‘ Contributions to our Knowledge of Subjective Vision.” In this dissertation he explained how some properties, and even some structural relations of the eye, can be in- vestigated by means partly psychological, partly physiological, which otherwise require for their discovery the most minute microscopical exami- nation. This essay decided his line of research ; it opened a new world to his fellow-labourers, and won for himself the approbation of Gothe, who was engaged in similar pursuits. Shortly afterwards he became assistant to the Professors of Anatomy and Physiology, Ilg and Rottenberger. In 1820 Purkinje published in the ‘ Medicinische Jahrbiicher des Gsterreich- ischen Staates,’ a paper on Vertigo, from observations made upon himself, In 1822 he was appointed to the Professorship of Physiology in the Univer- sity of Breslaw, on the recommendation of Dr. Rust, of Berlin. At Easter in 1823 he entered upon his duties at Breslaw. In consequence of preju- dice against Austrians on the part of the Medical Faculty, and a desire for the appointment of another person, he was not well received at first, but in the course of two years he overcame all dislike by the extent of his acquire- ments, and his urbane and unassuming demeanour. The inaugural disser- x tation required of the newly-appointed Professor had for its title, “* De examine physiologico organi visus et systematis cutanei.” In this dis- sertation he described the now well-known method of investigating the structure of the retina by the appearance seen after waving a flame beside the eye. He followed out this subject in a work entitled ‘‘ Observations and Experiments on the Physiology of the Senses, or new Contributions to the Knowledge of Subjective Vision,” published in 1825. In the course of the same year the Faculty of Medicine of Breslaw resolved to send their congratulations to Blumenbach on the fifteenth anniversary of his doctorate, accompanied by an original memoir on a suitable subject. Purkinje’s offer to write the memoir was gladly accepted. He took for his subject the elementary origin of the bird’s egg within the ovary, and its subsequent progress up to the time of its deposition. This investigation, which occupied him for three months, resulted in one of the most important physiological discoveries of his time, that of the germinal vesicle, now generally known as the “‘ vesicle of Purkinje.”” The congratulatory memoir in which it was first described and figured was afterwards published independently under the title of “‘ Symbole ad ovi avium historiam ante incubationem,” 1830. In 1828-30 he entered upon a microscopical examination of the organization of plants. The elastic fibres of various vessels of plants, and the receptacles . of pollen and seed capsules, which scatter the pollen and the seed, especially attracted his attention. The account of these researches was published in 1830: ‘ De cellulis antherum fibrosis nec non de granorum pollinarium formis, commentatio phytotomica.” On the recommendation of Mirbel, the Monthyon Prize was awarded to him by the French Institute for this essay. In the spring of 1833 he un- dertcok the observation of the developement of the tadpole through its various stages. He carefully examined the cilia which at first cover the whole body, then the head, and lastly only the branches of the gills. In the course of the same year Professor Valentin began his researches on the organization of the ovum of mammals, and while examining the funnel of the oviduct of a rabbit, observed a movement of a granule on the mucous membrane of the oviduct while floating in water, and attributed it to spermatozoa. But Purkinje traced the motion to cilia on the edge of the membrane. This discovery of ciliary motion in a warm-blooded animal led to a joint research, and to the publication of the work ‘ De phe- nomeno generali et fundamentali motus vibratorii continui in membranis cum externis tum internis animalium plurimorum et superiorum et in- feriorum ordinum obvii, commentatio physiologica,’ 1835. On entering upon his duties at Breslaw he established a physiological institute in his own house, where students were furnished with the means of examining microscopically the elementary parts of human bodies and those of animals, and of drawing and accurately describing them. These researches supplied the materials of a series of academical dissertations, many of which disclosed new methods of microscopical investigation, a field of research then beginning to be generally cultivated after having been X1 comparatively neglected since the days of Malpighi, Swammerdam, and Leeuwenhoek. Others again treated of various physiological or anato- mical subjects. In the first of these essays, by Krauss, in 1824, ‘De cerebri lzesi ad motum voluntarium relatione, certaque vertiginis directione ex certis cerebri regionibus lesis pendente,’” by the introduction of his theory of vertigo, he confirmed and extended the discoveries of Flourens and Magendie respecting the activity of the cerebrum and cerebellum. In another, by Wendt, in 1833, he announced the important discovery of the sudorific glands and their excretory ducts in the human skin. In another work of this description, ‘De penitiori ossium structura observationes ’ (1834), by Deutsch, also in ‘De penitiori dentium humanorum struc- tura’ (1835), and in ‘ Meletemata circa mammalium dentium evolutionem ” (1835), by Raschkow, new discoveries made by Purkinje are announced, These were followed by ‘ De penitiori cartilaginum structura symbole’ (1836), by Meckauer, ‘De arteriarum et venarum structura’ (1836), by Rauschel, ‘ De genitalium eyolutione in embryone feminino observata’ (1837), and ‘ De musculari cordis structura’ (1839). In the essay entitled «De formatione granulosa in nervis, aliisque partibus organismi animalis”’ (1839), Purkinje, in oppsition to the views of Remak and others, main- tained that the ‘‘formatio granulosa”’ or elongated corpuscles resembling cell-nuclei, which are found attached to the sympathetic nerves, are not peculiar to this system, and that they consist of a newer material resembling protoplasm, out of which the more matured portions derive their growth. In the essay ‘ De velamentis medulle spinalis,? he made known the dis- covery of a peculiar nervous plexus distributed on the pia mater of the spinal cord, which can be easily exhibited by maceration in acetic acid. An ac- count of these observations and of the existence of nerves in other mem- branous parts was given in a memoir (in Polish) published in the Year-book of the Medical Faculty of Cracow, and reproduced in German, with additions, in Miller’s ‘ Archiv’ for 1845. Two other dissertations appeared, the titles of which were, ‘ De structura uteri non gravidi’ (1840), and ‘ De numero atque mensura microscopica fibrarum-elementarium systematis cerebrospi- nalis symbole’ (1845). Purkinje having at length succeeded in convincing the Government of the necessity of establishing an independent institution for teaching physio- logy, a house was built in 1842 for the purpose of carrying on physio- logical researches, and a suitable grant made for defraying the stipends of assistants and other expenses. This example has since been followed in all the German and Austrian universities. Purkinje was the author of a paper “On the World of Dreams,” in ‘Hesperus ’ (1821), “On the Physiological Import of Vertigo”? in Rust’s Magazin (1827), “On Tartini’s Tones,” in the Bulletin of the Natural History Section of the ‘Schlesisch-patriotischen Gesellschaft’ for 1825, and ‘An Auscultation Experiment,’ in which, by means of an instrument of his invention, the points of rest and motion of a vibrating plate can be de- Xu termined by hearing alone, without the employment of sand, as in Chladni’s experiment. In Miiller’s ‘ Archiv fiir Anatomie und Physiologie’ for 1834 he described a compressorium for microscopic observation invented by himself, which soon came into general use, and soon afterwards published, conjointly with Valentin, an account of researches on ciliary movements observed in the cavities of the brain. In 1838 followed his interesting experiments, in conjunction with Pappenheim, on artificial digestion. In 1845, as already stated, the same journal published his observations on the nerves. Purkinje is also the author of many valuable articles in the ‘ Encyclopidisches Worterbuch der Medicinischen Wissenschaften,’ and Wagner’s ‘ Hand- worterbuch der Physiologie ;? of about sixty papers and lectures in the publications of the ‘ Schlesisch-patriotischen Gesellschaft’ of Breslaw, of physiological papers (in Polish) in the scientific journals published in Cracow, of reviews and articles on the Sclavonic languages and literature. He translated Tasso’s ‘ Gerusalemme Liberata,’ many of Schiller’s poems, and all his Lyrics into Bohemian. At the Naturforscherversammlung, held at Prague in 1837, he antici- pated Schwann in the announcement of the doctrine of the identity of fundamental structure of plants and animals, but with this distinction ' between the two cases, that he calls the elements of plants and those of animals, cells and granules respectively. In 1848 he attended the Meeting of the Sclavonic races in Prague, and was present at the celebration of the five hundredth anniversary of the foundation of the University, when the Degree of Doctor of Philosophy was conferred.on him. A long-cherished wish to be enabled to pass the remainder of his days in his native country was gratified by his nomination to the Professorship of Physiology in the University of Prague in the summer of 1850. His first care was the due equipment of the Physio- logical Institute, at that time recently established. This he effected in a satisfactory manner in the course of a year. His next endeavour was to promote the cultivation of the Natural Sciences among the Bohemian- speaking population, and with this view he became one of the editors of the Natural-History Journal ‘Ziva’ from 1853 to 1864, and also contributed many articles to the Journal of the Bohemian Museum. One of the most important of his later researches was a careful investiga- tion of the sound perceived in the interior of the skull. On examining the inmates of a deaf and dumb asylum, he found, as some previous observers had discovered, that almost all possess the power of hearing through the skull. _ His election as a Foreign Member of the Royal Society took place in 1850. He was corresponding Member of the French Institute, Member of the Academies of Vienna, Berlin, and St. Petersburg, and of many other learned Societies. He retained his vigour of body and mind up to the last days of his life. His death, after an illness of no long duration, on the 28th of July, 1869, was mourned by every class of Society in Bohemia. he lind ded aI LOGS xii Sir JAMes CiArk was born at Cullen in Banffshire in December 1788, and was educated at the parish school of Fordyce, and subsequently at the University of Aberdeen. In 1806 he entered a writer’s (solicitor’s) office at Banff; but, not liking the law, he was given the choice of the Church, with the promise of a ministry, or the profession of medicine. He chose the latter calling, and proceeded to Edinburgh. In 1809 he passed at the College of Surgeons, and then entered the medical service of the navy. He served at Haslar Hospital till July 1810, when he was sent to sea as Assistant-Surgeon in the schooner ‘ Thistle,’ which was going with des- patches to New York. The ‘Thistle’ was wrecked, with the loss of several of her crew, on the coast of New Jersey, and the survivors lost everything they possessed, and suffered great privations. On returning to England he was promoted to the rank of surgeon, and joined the ‘Collobrée.’ It is remarkable that this vessel was also wrecked on the _ American coast. He was then appointed to the ‘ Chesapeake,’ which had been recently taken by Sir Philip Broke, in his famous action, and served in her until 1814, when he was transferred to the ‘ Maidstone.’ In this ship he met with and formed a strong friendship for Lieutenant (after- wards Sir Edward) Parry, the celebrated Arctic navigator, and made, in conjunction with him, a series of experiments on the temperature of the Gulf-stream. During his service in the navy his attention appears to have been strongly directed to the question of climate, and the few notes he has left of this period of his life chiefly refer to observations he made on this subject, and to the hygienic conditions influencing the health of the men under his charge. In 1815 the ‘ Maidstone ’ returned to Baelaad to be paid off, and Sir James Clark was placed on half pay. In 1816 he went to Edinburgh, where he attended the University Classes, and graduated as M.D. in 1817. In 1818 he was asked to accompany a gentleman far advanced in con- sumption to the south of France. He went with his patient to Marseilles, Hyéres, Nice, and Florence, during the winter and spring, and in the summer to Lausanne. It was owing to this charge that his attention was especially drawn to the effect of climate on consumption, and that he com- menced the collection of meteorological and climatic data, with a view of studying their influence on that disease. In 1819 he settled in Rome, where English families were beginning to congregate, and remained there until 1826, when he removed to London. During his residence at Rome he spent the summers in visiting the medical schools and the watering-places of Italy, France, and Germany, and continued his studies on climate. In 1820 he published a small work, entitled ‘“‘ Notes on Climate, Diseases, Hospitals, and Medical Schools in France, Italy, and Switzerland,’ which formed the foundation of a subse- quent larger work on the ‘ Sanative Influence of Climate.’ In the same year he was married to Miss Stephen, the daughter of the Rev. Dr. Stephen, Rector of Nassau, and Chaplain to the Forces at New Providence. In VOL. XIX. 6 XiV 1826, being partly urged to the step by his friends, and partly influenced by consideration for his wife’s health, he left Rome ; and after a few months spent in visiting the chief medical institutions of France and Germany, and the Pyrenean and German baths, then very little known in England, he settled in London. In the autumn of 1827 he was attacked with typhoid fever, and was ill for several months. He never recovered perfectly from this attack; it left a delicacy of digestion behind it, and permanently enfeebled him. | Soon after settling in London, Prince Leopold, afterwards King of the Belgians, whose attention had been called to him by his investigation of the German waters, appointed him his physician, and this subsequently (in 1834) led to his appointment as physician to the Duchess of Kent. In 1829 he published his larger work on the ‘Sanative Influence of Climate.” This work, which was long considered the standard book on climate, and went through several editions, has had a very wide influence, not only on medical practice, but on the collection of meteorological and other data respecting climatic conditions. He subsequently (1832) pub- lished articles on air and climate in the ‘ Cyclopzedia of Practical Medicine.’ In the autumn of 1829 Prince Leopold, who was then engaged in the negotiation which resulted in his refusal of the crown of Greece, offered, if he accepted the crown, to take Dr. Clark to Athens; but this he declined. He was elected a Fellow of the Royal Society in 1832, and in 1835 pub- lished his ‘Treatise on Consumption and Scrofula,’ which, as well as the work on climate, was translated into Italian, German, and French, and passed in this country through several editions. Soon afterwards he wrote an article on tubercular phthisis in the ‘ Cyclo- peedia of Practical Medicine.’ Two years subsequently, on the accession of Her Majesty, he was ap- pointed Physician in Ordinary, and subsequently received a similar ap- pointment to Prince Albert. From this time the life of Sir James Clark (he was made a baronet in 1838) was spent in the discharge of his responsible duties as medical adviser to the Court, and in the fatigues of a London practice. It was therefore impossible for him to continue his scientific observations on climate, or even to prosecute further his more purely professional inquiries. But indirectly, in this latter period of his life, he lent a most powerful aid to science. | : He was always ready to help, and to use his influence, which yearly became greater, both with the Court and with the leaders of parties, for the furtherance of scientific objects, and for the advance of education. It is difficult to give a complete account of what he did in this direction, as he has left no records. He was, indeed, singularly indifferent to the recog- nition of his services, and, provided the end was gained, did not desire that his share in it should be known. But his chief influence appears to have been directed to the improvement of medical and of general education, XV to fostering special scientific instruction, to the promotion of sanitary mea- sures, to the improvement of the Lunacy Laws, and of the public medical Services. He appears to have always taken a deep interest in medical education. Early in life he had published in Italian a work addressed to Professor Tommasini on English medical literature, and some time afterwards he published some ‘ Observations on the System of Teaching Clinical Medi- eine in the University of Edinburgh, with suggestions for its improvement.’ He had also corresponded with both French and Italian physicians on this point ; and in the summer of 1825 he had spent several months in Paris for the purpose of observing the method of clinical teaching followed by _Laennec. | When, therefore, in 1838 the University of London was founded, and he wasasked to serve on the Senate, he was fully prepared to deal with this subject of medical education; and it is to a considerable extent to his labours at that time, and subsequently, when further changes were made in the curriculum, that the present examining system of the Medical Section of the University owes its shape. The leading features of the scheme which, in consultation with experienced medical teachers, he adopted, and which he advocated in the Senate, were to require evidence of a certain time having been spent in the study of medicine, but not to demand or to rely on many certificates of attendance, but to trust to a searching examina- tion; to split up the examination into two (and subsequently into three) parts, to be undergone at different stages of education, and to make the examination as practical and as thorough as possible. Clinical examina- tions were not, however, at first employed, but he subsequently obtained the introduction of this important part of medical examination. He continued to serve on the Senate until 1865, when he resigned, to the great regret of his colleagues. In 1854, when the Government determined to open the Indian medical service to unrestricted competition, he was requested to organize the method of medical examination, He did so, and gave this examination the form which, with a slight alteration, it has since retained. In this exammation he recommended the introduction of practical surgical and medical tests ; and to this may be traced much of the improvement which has taken place of late years in all parts of the kingdom in practical medical teaching. In 1858 he was appointed by the Crown a Member of the General Council of Medical Education which was constituted under the Medical Act of that year. He served on this body till December 1860. In connexion with medical education, he interested himself on the subject of Medical Reform, and in 1842 and 1843 he wrote two letters to Sir James Graham on that subject. The second letter, which gives a résumé of the first, urges the need ‘“‘ for a good and uniform system of medical education,”’ which he says should be the same throughout the empire for every medical practitioner. He then sketches the constitution of a body XV1 to whom ought to be delegated the power of carrying out the principles of education to be laid down by the Government. He had evidently formed an idea of a General Medical Council, which may yet some day be turned to account. | He did not, however, restrict his labours to medical education. He took a deep interest in the improvement of the Universities generally, and assisted Prince Albert in the projects which eventually ended in the altera- tions in the Universities of Cambridge and Oxford. Ata later date he was very active in alding the reconstruction of the University of Aberdeen. His greatest attempt to improve purely scientific education was made in connexion with the College of Chemistry. He was deeply impressed with the defective opportunities of studying practical chemistry in this country as compared with Germany, and with the unfavourable influence that deficiency would have, not only on our scientific standing, but on our powers as a manufacturing nation. The influence of Liebig’s doctrines on agricultural chemistry and on the improvement of the productive powers of soil were also at that time attracting great attention in England, and impressed him greatly with the importance of cultivating this subject. Whether the State should or should not more or less assist the teaching of pure science, or should leave this to the independent exertion of institutions or private individuals, is a matter which need not be here discussed. Sir James Clark’s opinion appears to have been that the Continental system of State aid had the effect of overweighting England in the race, and that if we wished to maintain our equality in science, we had no option but to imitate to a certain extent the Continental plan. The College of Chemistry, however, in the first instance, was intended to be self-supporting. it was commenced in 1845 by Dr. Gardner; and Sir James Clark soon became one of its most active supporters, and through his influence Prince Albert interested himself greatly in it. In the summer of that year, when the Queen and Prince were in Ger- many, Professor von Liebig was requested by Sir James to name some chemist who could carry on in England the same kind of practical instrue- tion which had made Giessen so famous. Liebig mentioned three names, and fortunately circumstances led to the selection of Dr. Hofmann. Through the influence of Prince Albert, Dr. Hofmann obtained leave from the Uni- versity of Bonn for two years, and soon afterwards the College of Chemistry was opened. How successful it was in a scientific point of view, even from the first, needs no record; but its expenses were heavy, and perhaps the College might even have been closed from pecuniary failure about the year 1852 had not the Prince Consort, urged on by Sir James, so exerted his influ- ence that the Government consented to give a small assistance, and at length the College of Chemistry eventually became incorporated with the Royal School of Mines. Since that time the College (which is partly self- supporting) has done much to diffuse among our manufacturing and agri- XVI cultural population a knowledge of Chemistry, and to advance the science by original research. It is to be regretted, however, that the College of Chemistry, originally established as an independent institution, self-sup- porting, or aided, if necessary, by private means, could not maintain itself on that footing. As far as possible also Sir James Clark gave a warm support to all plans for promoting the study of Natural History, and was ready to urge on the Government at any time any reasonable mode of doing this, or of furthering independent inquiries. Passing from pure science, he had a great share in the sanitary move- ment which has been so marked a feature of our days, although his name was not brought before the public so prominently as that of others who had really less influence. From a very early period he had been a very strong advocate of measures calculated to prevent disease and to improve the public health. He therefore used his influence with the Government to Institute the Health of Towns’ Commission, and those other early inquiries which were the foundation of the present movement. He was at this time intimately acquainted both with Andrew and George Combe, and estimated very highly the philosophical characters of the two brothers. Some years afterwards he edited and partly rewrote one of Andrew Combe’s Hygienic works on the Management of Infancy. At a very early date also, long before the Crimean war, he did what he could to get the sanitary state of the army and navy inquired into and remedied. There can be no doubt that his service in the Navy had impressed him with the urgent importance of this subject, and had also given him a strong conviction of the waste of life in warlike operations. Owing probably to their knowledge of his exertions in this direction, the Government during the Crimean war requested his cooperation in the organization of Supplementary Civil Hospitals, in support of the Military Hospitals, which were overflowing and had proved unequal to the work entailed by a severe campaign. He assisted in the deliberations which resulted in the establishment of the Smyrna Hospital; and subsequently, when a second hospital was required, the Government requested him to undertake the entire organization. He did so, and the result was the great Hospital of Renkioi on the Dardanelles, which was intended for 3000 sick. This hospital, the design of which was made by Mr. Brunel, has proved the model of the American Wooden Hospitals established during the late civil war, and indirectly has given rise to many of the arrangements in field hospitals in war which were carried out in Italy and Germany in the campaigns of 1859 and 1866, and are now being repeated on a still larger scale. It was therefore not surprising that after the Crimean war he was asked to serve on the Royal Commission, presided over by Mr. Sidney Herbert, for inquiring into the health of the army; and he had no small share in XV shaping the conclusions arrived at in that well-known and important inquiry. He subsequently took an equal interest in the Indian Sanitary Commission ; and it is really chiefly to his exertions and his influence with the Government (in support of the persistent action of Miss Nightingale, Sir Ranald Martin, Dr. Sutherland, and others) that we must attribute the advance which has been made in carrying out that most important reform, a reform which will influence not only the European soldiers in India, but the many million inhabitants of that empire. It is not wished to claim for Sir James Clark more honour than is due. There were many other labourers in the field, and no one man unassisted could have done such great works. All that is urged for him is that he was one of the earliest of those who saw the importance of sanitary science, and that he was ever ready with time and thought and influence to aid in the progress of inquiry and reform. In connexion with military medical arrangements, he served on the Committee which organized the Army Medical School now stationed at Netley; and he continued to the last moment to take the warmest interest in everything connected with that institution. In addition to the work of inquiry on sanitary legislation among the civil population and in the public services, he was very much interested in the legislation for the insane. In 1855 an American lady, Miss Dix, who was visiting the lunatic asylums of England and Scotland, was refused ad- mission into some of the private asylums in the latter country. In order to compass her wishes, she obtained introductions to some influential per- sons, among others to Sir James Clark, and the inquiries then set on foot led to the appointment of a Royal Commission to inquire into the Scotch Lunacy Laws. In this inquiry, and in the appointment of the Lunacy Commissioners which followed the Report of the Royal Commission, Sir James Clark took an active share; and in after years, when various attempts were made to revert to the old state of things, he spared neither time nor trouble to stem the retrograde current by correspondence and verbal remonstrance with Members of Parliament and Members of the Cabinet ; indeed, after his death, the Lord-Advocate quoted in Parliament a letter from him as a justification of the foundation of the Scotch Lunacy Board. Only two years before his death he wrote a life of Dr. Conolly, the object of which was not only to perpetuate the memory of his friend, but also to place before the public the true treatment of the insane, and to rebut the attempts, certainly feeble enough, which have been made to impair the wise and benevolent mode of treatment which Conolly did so much to popularize. When it is considered that all these labours (and in the true sense of the word his exertions were labours) were carried on in addition to the work entailed by his Court duties and a large private practice, the great activity of Sir James Clark will be appreciated. In this sketch only some of the public services rendered by him can be XIX referred to; for his mode of using his influence was so unostentatious, and his desire for a recognition of his services so small, that much of what he did is searcely known; and the want of specific details in showing how his influence was brought to bear in so many ways is owing to the modesty of his nature. Justice, too, has hardly been done in the foregoing lines to his scientific knowledge and sympathies. In this respect, as in his constant endeavour to promote the wellbeing of his fellowmen, he was so Jittle self- obtrusive that few men knew the extent of his acquirements. He paid, even to within a week of his death, constant attention to scientific progress, and especially to its practical application. Among his notes written but a few weeks before his last illness are details of the composition and mode of action of chloral. It was this union of a scientific spirit with great bene- volence of character which, aided by a large experience abroad and at home, made him so excellent a physician. His position at the Court necessarily occupied much cf his time and thoughts; he was unceasing in his attention to the health of the Queen and of her children, and the Royal family owe to him much of that blessing of health which has happily been their lot. He was on most confidential terms with the Prince Consort ; and the Prince found in him a congenial adviser oa all points connected with education and science. The Queen’s trust in him was early and firmly implanted, and was never impaired, and her sympathy and, we can truly say, affection for him were manifested to the last. Sir James Clark retired from private practiee in 1860, and removed to Bagshot Park, which Her Majesty had lent him for his life. He died there on the 29th of June, 1870, in the eighty-second year of his age, re- taining almost to the last hour of his life a warm interest in all scientific progress, and a heart-felt sympathy with every step which would promote the improvement and happiness of his fellowmen. Wiiiiam Axien Mituer, Vice-President and Treasurer of the Royal Society, was born at Ipswich, in Suffolk, on the 17th of December, 1817. He was indebted for his early education to his mother, whose memory he cherished with the greatest love and respect, and whose quiet, sagacious nature was reflected in him. Mrs. Miller had a favourite maxim, ‘‘ Take everything by the smooth handle; and if a thing has not got a smooth handle, make one!’ Dr. Miller was actuated through life by the spirit of this axiom ; and we have known him, when giving advice to a friend who sought it, introduce the remark, “‘ Take it by the smooth handle.” Miller passed one year in Merchant Taylors’ School, and two years at Ackworth, in Yorkshire, in a school belonging to the Society of Friends— the same in which Luke Howard took so great an interest that he purchased the Ackworth Villa estate, and made it his summer residence during some years. Luke Howard’s partner, William Allen, F.R.S., the manufacturing chemist, and author, conjointly with Mr. Pepys, of the well-known researches VOL. XIX. c XX on respiration, was the friend after whom Miller was named. Miller’s natural simplicity of character probably received its outward expression from this early contact with influential members of the Society of Friends. It was at Ackworth that he first distinctly remembered having acquired a taste for science, and a desire to devote his life to its cultivation ; and this was not so much from the chemical lectures, or rather the chemical experiments, - which were shown to some of the boys, as from the fact that Miller was occasionally invited to look at the stars through a telescope belonging to one of the masters. These early impressions bore fruit in the chemistry of the stars, with which his name is now associated. At the age of 15 he was apprenticed to his uncle, Mr. Bowyer Vaux, one of the honorary surgeons in the General Hospital at Birmingham, of which, during nearly twenty years, his father, Mr. William Miller, was secretary. After five years he entered the medical department of King’s College, London, where his superior knowledge of chemistry over that of the other students attracted the attention of Professor Daniell, who more than once expressed his surprise in the inquiry, “‘ Where did you get your knowledge from ?” One of those opportunities that occur in the lives of most people, but are taken advantage of only by superior men, occurred in connexion with the chemistry lectures. Miller had no taste for surgical practice, and preferred, if possible, to get some employment in the laboratory of a manufacturing chemist, rather than become a medical practitioner. Indeed he did per- form some analyses for the Messrs. Chance, while in treaty with them for more permanent employment. But the laboratory assistant at King’s College having been disabled by illness, Daniell engaged the services of Miller; and when the office of Demonstrator in the laboratory became va- cant in 1840, he was appointed to the post. It should be mentioned that in 1839 Miller obtained the Warneford Prize for the encouragement of theological studies among medical students, and in 1840 he passed a few months in Liebig’s laboratory at Giessen. In 1841 he became Assistant Lecturer for Professor Daniell, and also took his degree of M.B. in the University of London, proceeding to M.D. the following year. He also assisted Professor Daniell in various scientific inquiries, and conducted the experiments on the electrolysis of saline compounds, his name being as- sociated with that of Daniell in the paper that appeared in the Philoso- phical Transactions for 1844. In the following year he was elected a Fellow of the Royal Society, and on the death of Professor Daniell suc- ceeded to the vacant chair of Chemistry in King’s College. The writer of this notice was engaged in assisting Professor Daniell to bring out the third edition of his well-known work entitled ‘ Meteorological Essays,” and on the sudden death of the author he requested Dr. Miller to cooperate with him in completing the work, to which he readily assented. Dr. _Miller was engaged about this time in some experiments on Spectrum Analysis. They were conducted in a sort of lumber-room below the seats of the Chemical Theatre, and formed the subject of a paper which was XX1 read before the British Association and published in 1845 in the Philo- sophical Magazine (Series 3, vol. xxvil. p. 81). He thus became inter- ested at an early period in the subject of spectrum investigation. | Miller continued during some years to use as his text-book Professor Daniell’s ‘Introduction to the study of Chemical Philosophy,’ supple- mented at a later period by Fownes’s ‘Manual of Chemistry.’ The writer of this notice repeatedly urged Dr. Miller to bring out a work of his own, which should be better suited to the wants of his pupils; but he hesitated in doing so lest he should at all interfere with his predecessor’s work. ‘I must prepare the book,” he said, ‘from my lecture-notes, and you are not aware how much of Daniell I have in them.’ For some time his idea was to accede to a proposal of the publisher of Daniell’s work to bring out a third edition, making such additions thereto as the progress of science required, and to maintain it in its old position as the text-book. But on looking over Daniell with this view, he found that so many addi- tions and alterations would be required as greatly to supersede the author’s peculiar touches; so that he finally decided to produce a new work, and the first volume accordingly appeared in 1855. In the preface to this volume, which was devoted to ‘‘ Chemical Physics,” the author stated that * he had decided to leave untouched the work of his late master, as the true exponent of his views, upon some of those branches of science which his researches had contributed to advance and adorn.” The two subsequent volumes on “‘ Inorganic”’ and “ Organic Chemistry,” which appeared, the one in 1856 and the other in 1857, were written from Miller’s lecture- notes, as was also the case with the ‘‘ Chemical Physics,’’ the notes being so amplified as to form continuous reading, a process which led te so many insertions and alterations as to make the manuscript difficult to read. But the effect of this mode of treatment was so far advantageous that when the books were introduced to the students, they, so far from having to conform to any new method, seemed to recognize in the new text-books the very lectures they had heard. The three volumes of Miller’s ‘Elements of Chemistry’ passed through several editions, and were reprinted in the United States of America. While not professing to set forth any marked original views, the work affords a clear and comprehensive exposition of the science, and soon became deservedly popular. In the later editions Miller adopted the new method of notation in chemistry. His conservative principles led him to resist this change as long as it was possible to do so. Moreover, having been, during so many years, accustomed to the old notation, he never took kindly to the new. Indeed it was part of Miller’s character to grasp a new idea with a certain amount of mental siowness; but when once fairly appreciated, it was held tenaciously and not given up without a severe struggle. But he was so conscientious that he would sacrifice every thing to what he held to be the truth. The writer has known him to refuse to hold any further intercourse with a foreign man of gcience whom he had received into his c2 Xxil house and assisted in various ways, on hearing the expression of a doubt as to the benevolence of the Almighty for permitting him to undergo so inuch trouble. Soon after he became Professor, he was on one occasion giving evidence ina court of law on some scientific point connected with a patent, when, during the cross examination, the Judge made a remark which had the effect of questioning the veracity of the witness. Miller felt this so keenly that he fainted, and had to be carried out of court. After a short interval the Judge sent to inquire how he was. Miller said, **T shall be better when his Lordship does me justice.’ On his return, the counsel for the cross examination was proceeding to put questions in the spirit of the objection, when the Judge stopped him, stating that he had misunderstood the witness, and explained how. As a lecturer Miller was more successful in style and expression than as a writer, for his written composition had some tendency to become in- volved. One of the best specimens of his lectures is that on Spectrum Analysis, given before the British Association at Manchester in 1861, at the time when Kirchhoff’s researches had made the subject more than usually popular. One part of this lecture was devoted to an historical re- view of that remarkable branch of chemico-physical research ; and so little attention had been paid to this part of the subject that when a large - audience were collected to hear, as they supposed, an account of Kirchhoff’s discoveries, they were not a little surprised to find Kirchhoff occupying the end of a long series of illustrious names, from Newton m 1701 to Wollas- ton in 1802 and Fraunhofer in 1815; while the various other names were arranged after the fashion of a genealogical tree, under the four heads of (1) Cosmical lines, (2) Absorption-bands, (3) Bright lines produced by the electric spark, and (4) by coloured flames, the four branches uniting in the names of Kirchhoff and Bunsen, 1860. On the morning of the day appointed for that lecture, successful and brilliant as it was, Dr. Miller was seized with one of those bilious attacks to which he was subject, and was so prostrated that he had to keep his bed nearly up to the time of the lecture, and return to it immediately after its close. This gave occasion to a little incident which deserves to be noted as illustrative of the cautious habit of forethought of the man. In moving to the front of the crowded platform with a bottle containing red nitrous fumes in his hand, in his weak state he stumbled and fell, breaking the bottle in pieces. Immediately he sprang to his feet, exclaiming ‘‘I have another!” on which a round of applause caused him to remark, asif to himself, ‘I am too old a lecturer to rely upon one bottle.” This lecture was repeated before the Pharmaceutical Society of Lon- con on the evening of the 15th January, 1862, and printed in the Society’s Journal for February of that year. The historical details given in it have been largely used by subsequent writers, presenting, as they do, in a very clear manner, the results obtained by the earlier workers on the Spectrum. It was on returning from this lecture to his house at Tulse Hill, with his XXIH friend aud neighbour Mr. (now Dr.) Huggins, that Miller assented to a pro- posal made by Mr. Huggins that they should unite in carrying ona series of experiments on the spectra of the heavenly bodies. Miller was at this time engaged in an elaborate series of experiments which formed the subject of a paper read before the Royal Society, 19th June, 1862, “On the Photo- graphic Transparency of various bodies, and on the Photographic effects of metallic and other Spectra obtained by means of the Electric Spark.” This paper is inserted in the Philosophical Transactions for 1862. The joint labours of Miller and Huggins were continued during about two years; and as the observations could only be made at night, they must have told on the energies of a man who was s0 actively employed as Miller in brain-work at College and elsewhere during the day. The first results of their observations are given in a note on the lines in the spectra of some of the fixed stars, dated February 1863*, from which it appears that a considerable time was devoted to the construction of apparatus suited to this delicate branch of inquiry; but they had at length “succeeded in contriving an arrangement which has enabled them to view the lines in the stellar spectra in much greater detail than has been figured or described by any previous observer.” They further add that, “ during the past twelve months, they have examined the spectra of the Moon, Jupiter, and Mars, as well as of between thirty and forty stars, including those of Arcturus, Castor, a Lyre, Capella, and Procyon, some of the principal lines of which they have measured approximatively. They have also observed 6 and y Andromede, a, 3, e, and n Pegasi, Rigel, 7 Orionis, 6B Aurige, Pollux, y Geminorum, a, y, and e Cygni, a Trianguli, e, 2, and n Ursee Majoris, «, (3, y, «, and » Cassiopeize, and some others.” When their labours were sufficiently advanced, they embodied their results in a memoir entitled ‘‘ On the Spectra of some of the Fixed Stars,’ which wag published in the Philosophical Transactions for 1864.- At asomewhat later period there is a jomt note on the spectrum of the variable star Alpha Orvionis, contained in the ‘ Monthly Notices of the Royal Astronomical Society,’ vol. xxvi.; and another joint note on the spectrum of anew star in Corona borealis, in the ‘ Proceedings of the Royal Society,’ vol. xv., dated May 17, 1866. Messrs. Miller and Huggins, for their “ conjoint discoveries in Astrono- mical Physics,” received each the Gold Medal of the Royal Astronomical Society ; and on the occasion of presenting these medals, the President, the Rev. C. Pritchard, M.A., F.R.S., after referring to a former inquiry as to ‘What is a sun?” remarked that the progress of science had led to the further query, ‘‘ What is a star??? ‘* For the first dawning of a distinct and intelligent reply to this question we are indebted to Messrs. Huggins and Miller.’ * * * We find them associated “ in the examination of the spectra of stars by means of an admirable and newly contrived apparatus which had required much thought and labour to construct. With this * Proceedings of the Royal Society, vol. xii. p. 444. XXIV instrument attached to the telescope it was possible not only readily to divide the sodium line D into its two compartments, but to exhibit also the nickel line which Kirchhoff had observed between them. The spectra of the stars were now, in the first instance, compared approximately with the superposed atmospheric spectrum already alluded to, for the purpose of suggesting what metallic lines probably existed in the star under obser- vation, and then were compared directly, by actual juxtaposition, with the actual spectra of those metallic vapours which had been already suggested. It seems impossible to conceive any process more rigidly or conscientiously exact than that which Messrs. Huggins and Miller thus skilfully adopted ; and here I may be excused for repeating that the attainment of the ulti- mate object of the research depended, not on any approximation, however close, of the stellar with the metallic spectra, but on the certainty of their absolute coincidence. In this way, during the space of two years and a quar- ter, many of the midnight hours of these gentlemen were passed in the scrupulous examination and measurement of the spectra of upwards of fifty stars; but in several instances the number of the fine dark lines, the in- evitable indices (be it remembered) of the material constitution of these distant worlds, were so numerous, that to measure and map them all the labour of months would barely suffice. The physical result of all this scrupulous and conscientious care was to discover the fact, or it may be to: confirm the suspicion, that those mysterious lights with which the firma- ment is spangled are in strict reality worlds fashioned, in their material con- stitution at least, not altogether differently from the fashion of the little orb on which we live; beyond the question of a doubt they are proved, by the investigations of our medallists, to contain at least the hydrogen, the sodium, the magnesium, the iron with which all terrestrial creatures are so familiar.” , On Tuesday, May 14th, 1867, Miller commenced at the Royal Insti- tution a course of four lectures on “ Spectrum Analysis, with its applica- tions to Astronomy.’ These lectures were reported in the ‘ Chemical News,’ under the revision of the author. Again, at the Meeting of the British Association at Exeter in 1869, he gave a lecture on Spectrum Ana- lysis to working men. This lecture was afterwards published in the ‘ Po- pular Science Review’ for October 1869. Miller was interested in the subject of water analysis, and, in conjunction with Professors Graham and Hofmann, prepared a Report for the Govern- ment ‘‘ On the Chemical quality of the Supply of Water to the Metro- polis.” This was printed in 1851. At a later period he undertook an investigation ‘“‘ Onthe combined Action of Air and Water on Lead,” and in 1865 gave a lecture before the Chemical Society ‘On some points in the Analysis of Potable Waters.” Quitting the subject of Miller’s original work, we pass on to a brief notice of the various services rendered by him to Science. He was on the Council of the Royal Society during the years 1848-50 and 1855-57, XXV and being elected Treasurer on the 30th of November, 1861, he served on the Council in an official capacity till the time of his death. His metho- dical and punctual habits, his knowledge of affairs, and his excellent judgment, with the earnest and lively interest he took in the welfare of the — Society, rendered his special services as Treasurer of the utmost value; whilst the same high qualities, combined with his accomplishment in . science, singularly well fitted him for the various duties he had to perform as Member of the Council and a chief Officer of the Society. The date of his election to the Fellowship is 1845. Mr. Gassiot, who knew Miller intimately, referring to his merits as Treasurer, writes, “‘a more straightforward officer, or one more devoted to upholding the dignity and promoting the usefulness of the Royal Society, I do not know ; and there is probably no one with whom Dr. Miller com- municated on the subject so freely as myself.’’ Mr. White, the Assistant- Secretary, who habitually had to transact business with him, adds, “My own experience of Dr. Miller was, that on walking down to King’s College I could tell beforehand the mood in which I should find him—always uniform and considerate. His decision on questions brought before him was generally quick and sound, and he was ready in detecting the weak points of an argument. In the whole period that he was Treasurer I never had a single disagreeable word with him.” In 1866 Dr. Miller was nominated a Member of the Committee then appointed for the purpose of superintending the Meteorological Observations made by direction of the Board of Trade, and served on it till the time of his death ; he was also an active Member of the Committee of the British Association for superintending the Kew Observatory, and devoted much time to that work. The definition of the arrears to be executed under the superintendence of Mr. Balfour Stewart, as entered on the Minutes of the Committee, 9th March, 1870, was written by and. inserted at Dr. Miller’s particular request, in order specially to define the important work that has yet to be completed by the time when the connexion of the Observatory with the British Association shall cease. It may here be mentioned that whilst a Member of the Committee ap- pointed to advise on the scientific arrangements for the marine researches carried on during the voyage of the ‘ Porcupine’ in 1869, Dr. Miller was happy enough to contrive a thermometer adapted for taking deep-sea tem- peratures, which has been found admirably to fulfil its purpose*. Miller was one of the original founders of the Chemical Society, and frequently presided over its meetings, as well as occupied a place at its Council Board. Along with his other various occupations, Dr. Miller was a Member of the Senate of the University of London, to which he was appointed, on the recommendation of Convocation, early in 1865; and his sound judgment and knowledge generally, as well as his accomplishment in chemical and physical science and his experience as a teacher, gave * Proceedings of the Royal Society, vol. xviil. p. 408. XXV1 ereat weight to his opinion in the deliberations of that bedy, and caused his loss to be severely felt. In addition to the various honours which rewarded Miller’s position as a scientific man, it should be mentioned that he received the degree of LL.D. at the University of Edinburgh, on the occasion of the installation of Lord Brougham as the first Chancellor, that of D.C.L. at the Univer- sity of Oxford in June 1868, and that of LL.D. at the University of Cambridge in May 1869, after giving the Reade Lecture, which on this occasion was on the Coal-tar Colours. Perhaps the most marked feature in Miller’s character was sagacity combined with a deep sense of religion. His religious views may be gathered, although imperfectly, from an address entitled ‘The Bible and Science,’’ delivered at the Church Congress in Wolverhampton, October 3rd, 1867; also from his “ Introductory Lecture,” on the opening of the Medical Session at King’s College, October Ist, 1859, published under the title, ‘‘ Hints to the Student on commencing his Medical Studies.” In conclusion, the writer may be allowed to repeat what he said in a short notice at the period of Miller’s death, drawn up at the request of the editor of the ‘Chemical News’ :—‘“‘ During a quarter of a century Miller continued to lecture with unceasing activity, and to take part in the manage- meat of King’s College, every one, from the Principal and Professors to the youngest student, being anxious to obtain his advice and assistance. It was impossible to come in contact with him without feeling one’s self in the presence of a man of pure nature, of spotless integrity, of sound and sagacious judgment, and of true gentlemanly feeling. His loss will be deeply felt, especially in King’s College, in the Royal Society, in the Mint, andthe Bank of England, where he was one of the Assayers. He will be missed in the Courts of Law, where his clear perception of patented pro- cesses, and his strong sense of justice, made him respected alike by judge and counsel. He will be missed by the manufacturers who sought his advice ; but, above all, he will be missed by his own family, and by the few friends who had his confidence.” There had been symptoms of an overwrought brain for some months previous to his last illness, which took place on the journey to Liverpool, 13th September, 1870, at the time of the British Association gathering, which, however, he was unable to attend, his illness culminating in apo- plexy on the 30th of the same month. His remains were brought from Liverpool and interred in the cemetery at Norwood, by the side of those of his wife, whom he survived one year. He died on the anniversary of her burial, and at the comparatively early age of 53. Ie married, in 1842, Lliza, eldest daughter of the late Mr. Edward Forrest, of Birmingham, by whom he leaves issue, two daughters and one son.—C. T. XXV Joun T. Graves, M.A., F.R.S., was son of John C. Graves, of Dublin, Barrister-at-Law. Hewas born in Dublin on the 4th of December, 1806, and, passed some years in the school of the Rev. Samuel Field, Westbury- on-Trym, Somersetshire. He entered Trinity College, Dublin, in 1823, and was a class-fellow of Sir William Rowan Hamilton, with whom, though living at a distance, he kept up a life-long friendship. In his under- graduate career he was distinguished in both Science and Classics, and at his Degree Examination in 1827 was awarded the Classical Gold Medal, He soon after took an ad eundem degree at Oxford, and was incorporated in Oriel College, where he resided some time, and proceeded to the degree of M.A. He was also M.A. of Dublin University. On the 10th of June, 1831, he was called to the Bar as a Member of the Inner Temple, and for a short time went the Western circuit. In.the year 1839 he was appointed Professor of Jurisprudence in University College, London, in succession to Mr. Austin, and not long after was elected to be Examiner in Laws in the University of London. The records of his work as a lawyer are Twelve Lectures on the Law of Nations, published in the ‘ Law Times,” commencing April 25, 1845, and two elaborate articles contributed to the ‘ Encyclopzedia Metropolitana,’ on Roman Law and Canon Law. About this time he was a contributor to Smith’s Dictionary cf Greek and Roman Biography and Mythology. Among other articles from his pen are those on Cato, Crassus, Drusus, Gaius, and the Legislation of Justinian. As a scientific author Mr. Graves commenced his labours in his twentieth year. It was in October 1826 that he was engaged in researches on profound and subtle questions in analysis; the results he obtained were communicated to the Royal Society of London in the year 1828, and pub- lished in the Philosophical Transactions for 1829, under the title ‘An attempt to rectify the Inaceuracy of some Logarithmic Formule.’ ‘This paper gave rise to interesting and important discussions, with which the names of M.Vincent, Peacock, Ohm, De Morgan, Warren, Rowan Hamiiton, and others are connected. It was by meditating upon the results of this memoir that Sir W. Rowan Hamilton was led to his ingenious theory of Conjugate Functions or Algebraic Couples, as may be learned from Sir W. R. Hamilton’s abstract of a paper “On Conjugate Functions, or Algebraic Couples, as tending to illustrate generally the Doctrines of Imaginary Quantities, and as confirming the Results of Mr. Graves respect- ing the existence of two Independent Integers in the complete expression of an Imaginary Logarithm,” as well as from an abstract of a ‘* Memoir on the Theory of Exponential Functions,’”’ both published in the Report of the British Association for 1834. In continuation of the same and allied re- searches, Mr. Graves contributed a paper to the Philosophical Magazine for April 1836, ‘On the lately Proposed Logarithms of Unity, in iepli to Prof. De Morgan ;” and in November and December of the same year another, entitled “ Explanation of a remarkable Paradox in the Calculus of Functions, noticed by Mr. Babbage.” To the same journal were contri- XXVHI buted by him, in September 1838, a New and General Solution of Cubic Equations ; in August 1839 a paper on the Functional Symmetry ex- hibited in the Notation of certain Geometrical Porisms when they are stated merely with reference to the arrangement of points; and in April 1845 a paper on a Connexion between the General Theory of Nor- mal Couples and the Theory of Complete Quadratic Functions of Two Variables. A subsequent number contains a contribution on the Rev. J. G. MacVicar’s Experiment on Vision; and the Report of the Cheltenham Meeting of the British Association contains abstracts of papers communi- cated by him on the Polyhedron of Forces, and on = Congruence na= n-+1 (mod. p). The above list of papers, itself iacampluria is fa from representing ade- quately Mr. J. T. Graves’s contributions to mathematical science. The Transactions of the Royal Irish Academy contain many traces of his in- tellectual activity ; and by his long correspondence with Sir William Rowan Hamilton, commenced at an early period and maintained until death in- terposed, Mr. Graves may be said to have taken no small part in bring- ing to maturity the splendid conception of Quaternions, by which alone the name of Hamilton would have been rendered immortal. In his pre- face to the ‘ Lectures on Quaternions,’ Sir William makes frequent allusion to the suggestive character of his correspondence with hig early friend, and warmly expresses his indebtedness thereto. Mr. Graves was oue of the Committee of the Society for the Diffusion of Useful Knowledge. Inthe year 1839 he was elected a Fellow of the Royal Society, and he subsequently served upon its Council. He was also a Member of the Philological Society and of the Royal Society of Literature. For many years past he had taken interest in forming a collection of mathematical works of all ages and countries, a collection which, though only to be appreciated by the few, is by those qualified, who are acquainted with it, considered to be almost unique for historical curiousness and com- pleteness ; and nearly every book composing it was bound under his diree- tion with costly care and elegance. This portion of his library he be- queathed to University College, London, in. remembrance of his” former connexion as Professor with that Institution. In the year 1846, soon after his marriage with the daughter of the late — William Tooke, Esq., F.R.S., he was appointed Assistant Poor-Law Com- missioner, and on the constitution of the present Board in 1847 was made Poor-Law Inspector. He served efficiently in that department till the past month, when he sent in his resignation, an act which he did not long survive. He died on the 29th of March, at his residence in Cheltenham, at the age of 63. | { J : ‘ i “ye z.3 - ; vi y A i : a sdp)} AS ‘ 7. General Problem of Combined Streams.—In most cases the problem of combined streams takes one or other of the two following forms. In each of the two forms the areas of the nozzles a,, @,, &c. are given, and also the area of the throat, A. First Form.—The quantities given, besides the before-mentioned areas, are the pressure at the nozzles, p,, and the velocities of the component streams, v,, &c. The functional values given are those of §,, 5 So: 2 &c., i a, v, CoN Rta See a) , 22%) &e. Those functional - 0? 1 Sos 2 values are to be substituted in the equations (1) and (2); and the solution of these equations will give the numerical values of V and of P,. In the case of liquids of sensibly constant bulkiness, s,,, &c., and S, are quan- tities sensibly independent of p, and P,; and then equations (1) and (2) can be separately solved without elimination, giving respectively V and P,. Second Form.—Each of the component streams flows through a passage whose factor of resistance, f, is given, from a separate reservoir in which the pressure p and the elevation z of the surface above the junction- chamber are given. The resultant stream flows through a passage whose VOL. XIX. terms of p,, and of S, in terms of P,, 94 On the Mathematical Theory of Combined Streams. factor of resistance, F, is given, into a reservoir in which the pressure P and the elevation Z of the surface above the junction-chamber are given. These, together with the areas A, a@,, a,, &c., are the quantities given. The functional values given are those of the bulkiness, s,,,, 5,,., &c., and S,, as before; also the following values of the velocities, according to well- known principles in hydrodynamics ; for any component stream, fe 2g2@+2 sdp omy / ie 5 e . e . e (5) 1+f and for the resultant stream, 2gZ+2 SdP vay / [werefe ; > Sees seit The functional values given are to be substituted in equations (1) and (2), whose solution will then give the numerical values of p, and P,; and from these and the other data the numerical values of », &c. and of V may be calculated. ehhaced Appropriation of the Donation Fund. 145 B.—Account of Sums granted from the Donation Fund in 1870. 1. Mr. Warren De La Rue, for the enlarging of certain Solar Negatives obtained at the Kew Observatory ................ #11 11s. 2. Dr. Carpenter, for the purchase of a specimen of Pentacrinus | Joely DMIOCIISES GO IS ANE epee gat ice erie ar aad Paeher 25 3. Mr. Edward Waller, for the exploration of the Sea-bed on the North-western coast of Ireland by means of the Dredge, in con- tinuation of the researches made last year in H.M.S.‘ Porcupine’ 100 4. Mr. J. P. Gassiot, to defray expense of making six prints from the Negatives of Sun-pictures taken at the Kew Observatory during the years 1862-72, with the view of presenting them to the Royal Society, the Royal Astronomical Society, the Imperial Aca- demy of Sciences of Paris and of St. Petersburg, the Royal Aca- demy of Sciences, Berlin, and the Smithsonian Institution, Washing- iene 20 imi two PaAyIMENts) 9.0 le Se ON le 60 5. Mr. William Saville Kent, in aid ot a Zoological Dredging- expedition in a private yacht off the west coast of Spain and Por- LOGI. . cccnle phe Ganeeo oom Bp Fil rumto Bayo cue Serine ler etree a PRS rer 30 6. Dr. Bastian, for carrymg on certain experiments with a Di- gester capable of sustaining high Temperatures.,.............. 10 ——_——— £256 lis. xix referred to; for his mode of using his influence was so unostentatious, and his desire for a recognition of his services so small, that much of what he did is scarcely known; and the want of specific details in showing how his influence was brought to bear in so many ways is owing to the modesty of his nature. Justice, too, has hardly been done in the foregoing lines to his scientific knowledge and sympathies. In this respect, as in his constant endeavour to promote the wellbeing of his fellowmen, he was so little self- obtrusive that few men knew the extent of his acquirements. He paid, even to within a week of his death, constant attention to scientific progress, and especially to its practical application. Among his notes written but a few weeks before his last illness are details of the composition and mode of action of chloral. It was this union of a scientific spirit with great bene- volence of character which, aided by a large experience abroad and at home, made him so excellent a physician. His position at the Court necessarily occupied much of his time and thoughts; he was unceasing in his attention to the health of the Queen and of ber children, and the Royal family owe to him much of that blessing of health which has happily been their lot. He was on most confidential terms with the Prince Consort; andthe Prince found in him a congenial adviser on all points connected with education and science. The Queen’s trust in him was early and firmly implanted, and was never impaired, and her sympathy and, we can truly say, affection for him were manifested to the last. Sir James Clark retired from private practice in 1860, and removed to Bagshot Park, which Her Majesty had lent him for his life. He died there on the 29th of June, 1870, in the eighty-second year of his age, re- taining almost to the last hour of his life a warm interest in all scientific progress, and a heart-felt sympathy with every step which would promote the improvement and happiness of his fellowmen. ? wt WV eed UM" | = PROCEEDINGS OF apne eS 44 _;f THE ROYAL SOCIETY, VOL. XIX. No. 128. CONTENTS. June 16, 1870. PAGE XIV. On the Atmospheric Lines of the Solar Spectrum, in a Letter to the Pre- sident. By Lieut. J. H. HennessEy Bete sate Siig Cena yatee eee XY. On the Radiation of Heat from the Moon.—No. II. - the EARL OF Rosse, F.R.S. ah her Coen See ok ah AC 5 XVI. On Linear Differential | Equations —No. III. ee Wee Ei Rossen, E.RB.S. an Re Seem ahaha tte - ae 14, XVII. Observations with the Great Melbourne Telescope, in a Letter to Prof. eer by AE SU HOR Ys fe hens er\ eraeat ie eur aie eke ve ha 18 XVIII. Chemical and Physiological Experiments on living Cinchone. By J. BrovucutTon, B.Sce., F.C.S., Chemist to the Cinchona-Plantations of the Winer CrOVErMIMENh (6) va Tels ewe ewe i eo te) tO XIX. Researches on the Hydrocarbons of the Series Cy H2n+2.—VI. a C. SCHORLEMMER . eae oh te ean eS re : : . «20 XX. Formation of Cetyl-alcohol by a singular reaction. By C. SCcHORLEMMER. 22 XXI. Researches in Animal Electricity. By C. B. Rapozirre, M.D. 22 Misty Ob E RCSeVipdar ol sven 2c uls) ta nee era ome el. yoo Usk ace 29 On Approach caused by Vibration. By FREDERICK GUTHRIE 35 On Jacobi’s Theorem respecting the relative equilibrium of a Revolving Ellipsoid of Fluid, and on Ivory’s discussion of the Theorem. By I. TopuuntTer, M.A., F.R.S., late Fellow of St. John’s College, Cambridge 42. On the Theory of Continuous Reams. By JoHn Mortimer HeEppst, Mieebnsthy Cokes Kory tat oon ew eR ey emi 1 56 Remarks on Mr. Heppel’s Theory of Continuous Beams. By W. J. Macquorn Ranxine, C.H., LU.D., F.R.S. ree Pee mPa SS For continuation of Contents see 4th page of Wrapper. CONTENTS—(continued). COMMUNICATIONS RECEIVED SINCE THE END OF THE SESSION. PAGE Researches into the Chemical Constitution of the Opium Bases.—Part IV. On the Action of Chloride of Zinc on Codeia. By Avaustus Marruinssey, F.R.S., Lecturer on Chemistry at St. Bartholomew’s Hospital, and W. Bunnsipz, of SIG Iees sel OSpUbAl rots oe top gy coe Crea ane ama ed oi col heer tn «, pa eae can, ena ge Experiments on the Action of Red Bordeaux Wine (Claret) on the Human Body. By H. A. Parkes, M.D.,F.R.S., Professor of Hygiene in the Army MedicalSchool, ‘and Count Cyprian Woutowicz, M.D., Assistant Surgeon, Army Medical Staff. 73 On the Mathematical Theory of Combined Streams. By W. J. Macquorn Ran- mun, ©. b.D.,-F.R.SS. Lond.and Edin. . . .°, . testy ay ay NCH) Obituary Notices :— ECO) ASVARD) MIORVEEG Uc gb) Sy ie an ie ce elt aol nig Mle Rg Lr ain gen ie 1 VOEANN EIVANGEEIOTA EP UBRINGE 208 SO lie goat a a eee ls TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. VOL. XIX. PROCEEDINGS OF ih hoya SOCIETY: | CONTENTS. yo ] ty November 17, 1870. II. IIT. IV. i. PEL, PAGE . Researches into the Chemical Constitution of the Opium Bases.—Part IV. On the Action of Chloride of Zinc on Codeia. By Aveustus Mar- THIESSEN, F'.R.S., Lecturer on Chemistry at St. Bartholomew’s Hospital, and W. Burnsip#, of Christ's Hospital. (See page 71.) Experiments on the Action of Red Bordeaux Wine (Claret) on the Human Body. By H. A. Parxzs, M.D., F.R.S., Professor of Hygiene in the Army Medical School, and Count Cyprian Woxttowi0z, M.D., Assistant Surgeon, Army Medical Staff. (See page 73.) On the Mathematical Theory of Combined Streams. By W.J. Macquorn RawnkIne, C.E., LL.D., F.R.SS. Lond. and Edinb. (See page 90.) On the Fossil Mammals of Australia.—Part IV. Dentition and Mandible of Thylacoleo Carnifex, with Remarks on the pikes for its Herbivo- rity. By Prof. Owen, F.R.S. &c. Ay eNO aS aera one November 24, 1870. . Communication from the Secretary of State for India relative to Pendulum Observations now in progress in India in connexion with the Great Trigonometrical Survey under the Superintendence of Colonel J. T. Waker, R.H., F.RS. . On the Theory of Resonance. By the Hon. J. W. Strurr On the Aromatic Cyanates. By A. W. Hormann, LL.D., F.R.S. For continuation of Contents see 4th page of Wrapper. No. 124. 95 CONTENTS—(continued). November 30, 1870. ANNIVERSARY MEETING. PAGE MOM OUP MUATOM ye se ie ee ele el ge eee ee See EES isiOimbollows, GECCHSCONWOl sy 6 el ee ne le te a we ee le oe ——_—-_—— elected since last Anniversary . . ........ . . 114 PRMeresetOre ie VOsICen tb? yf 5 0 ie oe oe awe woes Soha ea Wile ar oh Ma ema OM OL UMC UNTCOMIS sre! oe ea Oe eae, ene pn ey s lection ol, Council and Officers. . 5. ee ee es 128 Biri rprertiep ete MaCNG Ga ec el See gan oe eae LZR ee ESO List of Presents. . . . ode Account of the Bios of ue sum of £1000 caealy ate ve Panliantoat to the Royal Society (the. Government a , to be ne in ue the advancement of Science . . 2 TSS Account of Sums granted from eo Boation noe in 1870 SA Mert Ain eae is LAI. TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. PROCEEDINGS OF Pie ROYAL SOGIET Y. VOL. XIX. INO E25. Gl it CONTENTS. December 8, 1870. PAGE Report on Deep-sea Researches carried on during the Months of July, August, and September 1870, in H.M. Surveying-ship ‘ Porcupine.’ By W. B. Carrenter, M.D., F.R.S., and J. Gwyn JEFFREYS, F.R.S. . . 146 _ December 22, 1870. I. On the Extension of the Coal-fields beneath the Newer Formations of Eng- land; and the Succession of Physical Changes whereby the Coal-measures have been reduced to their present dimensions. By Epwarp Huvi1, M.A., F.R.S., F.G.S., Director of the Geological Survey of Ireland . . 222 II. On the Constitution of the Solid Crust of the Earth. By the Ven. Jonx Henry Prart, Archdeacon of Calentta, M.A., F.R.S. . . . . . 228 ILI. Actinometrical Observations made at Dehra and Mussoorie in India, Octo- ber and November 1869, in a Letter to the President. By Lieut. J. H. PILUPNINESSE Vice cet nertr tsa RES wpe le env elay ache eis see January 12, 1871. I. Qn Fluoride of Silver—Part II. By Gzrorcr Gort, F.R.S. . . . . . 235 II. Some Experiments on the Discharge of Electricity through Rarefied Media and the Atmosphere. By CROMWELL FLEETWOOD VARLEY . . . . 286 Ill. Polarization of Metallic Surfaces in Aqueous Solutions, a new Method of obtaining Electricity from Mechanical Force, and certain relations be- tween Electrostatic Induction and the Decomposition of Water. By CROMWELL FLEETWOOD VARLEY . | -, 243 For continuation of Contents see 4th page of Wrapper. CONTENTS—(continued), January 19, 1871. PAGE I. On the Structure and Development of the Skull of the Common Frog (Rana temporaria). By W. Kircurn Parker, F.R.S. IJ. Method of measuring the Resistance of a Conductor or of a Battery, or of -a Telegraph-Line influenced by unknown Earth-currents, from a single Deflection of a Galvanometer of unknown Resistance. By HEnry Mance, Superintendent Mekran Coast and Persian Gulf Telegraph De- POSIREIHIETIG WMI PPACI CC a0 iy uc wy sr MRE eal dante tek oh Coie miata mtatem ome can Vie III. Measurement of the Internal Resistance of a Multiple Battery by ae the Galvanometer to Zero. By Henry Mance .... .« ‘ IV. Modification of Wheatstone’s Bridge to find the Resistance of @ Galvano- meter-Coil from a single deflection of its own needle. Pi Prof. Sir WIL- LIAM THOMSON, E.R.S. V. Ona Constant Form of Daniell’s ae By Prof. Sir Wirtau THOM- son, F.R.S. A aan, Metals Wo aN hes 612 utr ne VI. On the Determination of a Ship’s Place from Observations of Altitude. By IBKor Ole VVILLTAM LHOMSON, HR.Se oo oe ee ay ee bas January 26, 1871. ¥. On the Mineral Constituents of Meteorites. By N&rvin Story Masxe- tye, M.A., F.R.S,, Professor of Mineralogy, Oxford, and eee of the Mineral Bicpatiacent, British Museum . - : soe II. On the Organization of the Calamites of the Coal-measures. By W. C. Wituiamson, F.R.S., Professor of Natural EDS in Owens ee Manchester . ede lees ea a ae a ear are SOS clas MOREE NEE III. On Approach caused by Vibration. A Letter from Prof. Sir W. THOMson, LL.D., F.B.S8., &c. to Prof. FREDERICK GUTERIE, B.A. . eho List of Presents . TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. . 246 . 248 . 252 . 253 » 253 . 259 - 266 , 268 wag PROCEEDINGS OF THE ROYAL SOCIETY. VOL, XIX. oh | No. 126. CONTENTS. LX ip ye Peas, 1871. PAGE I. On Linear Differential i —No. IV. ror W. H. L. RUssett, RUNES ose ade gar ah cto wns mcr ek wal tein HRA eee ne cist IIT. III, IV. . Measurements of Specific Inductive Capacity of Dielectrics, in the Physical Laboratory of the eee of Glasgow. a J OHN C. Gisson, M.A., and THomas Barcnay,M.A..... . sais Dg te a 218) On the Uniform Flow of a Liquid. By Hmnry Mosrrey, M.A., D.C.L., Canon of Bristol, F.R.S., and posure Member of the Institute of PRUNANGS! se he a Ms i ‘ EPUaE ular aks Corte ably ahs 415) 0) February 9, 1871. . On the Effect of Exercise upon the Bodily Temperature. By T. CLIFFORD AutputtT, M.A., M.D. Cantab., F.L.S., Member of the Alpine Club, &. 289 . Observations of the Eclipse at Oxford, December 22, 1870. By Joun Paris, M.A., D.C.L., F.R.S., Evgiesccr of eee in the De (059 55 0 00 NA neat eee eect (ea ; ae yea) On the Problem of the In- and Circumscribed ‘Triangle. By A. CaytEy, lati: og. SB SR ges te ae GA hg SIPURA) On the Unequal Distribution of Weight and Support in Ships, and its Effects in Still Water, in Waves, and in Exceptional Positions on Shore. By BH. J. Rep, C.B., Vice-President of the Institution of Naval Architects. . 292 For continuation of Contents see 4th page of Wrapper. TT. IT. CONTENTS—(continued). February 16, 1871. PAGE . On some of the more important Physiological Changes induced in the Human Economy by change of Climate, as from Temperate to Tropical, and the reverse (concluded), By ALEXANDER Rarrray, M.D. (Hdinb.), moncconmeNa EMS. * Bristol se: Vie ew el ee. ws eee On a Registering Spectroscope. By Wittiam Hueeins, LL.D., D.C.L., E.R.S. e ® ° 9 ° ° e ° e e ° ° ° e e ° ° ° ° ° ° ) 317 February 23, 1871. . On the Mutual Relations of the Apex Cardiograph and the Radial Sphyg- mograph Trace. By A. H. Garrop, of St. John’s College, Cambridge . 318 On the Thermo-electric Action of Metals and Liquids, By GzorcE Gorz, vette eh ay hale ee Me SIS Gun ego weit Naat care ky Lays Wel aan oe MSTROIePCSCNIES, fat 2 he aiden) oe oy lob ee Ph ince pu Oc Syiaae Baar Obituary Notice :— DRE PAMEHS COLA K Ream ane oc oN Ne fae Wiel no wat ee Qc sb oon TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. ss PROCEEDINGS OF THE ROYAL SOCIETY: VOL. XIX. No. 127. II. II. III. it, II. III. CONTENTS. m ELOY March 2, 1871. PAGE . Further Experiments on the effect of Diet and Exercise on the Elimination of Nitrogen. By WH. A. Pankns, M.D,, ERS. . 1... 1. «se. Sad Magnetic Observations made during a Voyage to the North of Europe and the Coasts of the Arctic Sea in the Summer of 1870. By Capt. Ivan” BELAVENETZ, I.R.N., Director of the Imperial Magnetic Observatory, -Cronstadt. Ina Letter to ARCHIBALD Smiru, M.A., LL.D., F.R.S.. . 361 March 9, 1871. . Results of Seven Years’ Observations of the Dip and Horizontal Force at Stonyhurst College eee: from oe 1863 to March 1870. au the Revo8-d. PERRY... 6 SRNR inten ule, Mie ore: Preliminary Notice on the Production of the Olefines from Paraffin by Dis- tillation under Pressure. By T. E. THorrs, Ph.D., Professor of Chemistry in Anderson’s University, Glasgow, and Joun Youna. . . .. . . 370 Contributions to the History of the Opium Alkaloids. Part I.—On the Action of Hydrobromic Acid on Codeia. By C. R. A. Wricut, D.Sc. . 371 March 16, 1871. . Description of Ceratodus, a genus of Ganoid Fishes, recently discovered in rivers of Queensland, Australia. By ALBERT GuntHER, M.A., Ph.D., IT TD) gs TCU SUES i oa ain Oe AR a A a a A mS eR ar age Ng Age 818) On the formation of some of the Subaxial Arches in Man. By Grorar W. CALLENDER, Assistant Surgeon to, and Lecturer on Anatomy at St. Bar- BOOMME WaSmElOs iia koueeeu i tudes Cael ie la c's “ie wart) ah esa es OOO March 23, 1871. . Experiments on the Successive Polarization of Light, with the description of a new Polarizing Apparatus. By Sir CoarLes WHEATSTONE, F.R.S. . 381 On an approximately Decennial Variation of the Temperature at the Obser- vatory at the Cape of Good Hope between the years 1841 and 1870, viewed in connexion with the Variation of the Solar Spots. By EH. J. Sronz, FE.R.S., Astronomer ae at the ae of Good ae In a Letter to the Pes tient SF sas ee pir dren rehire fm Eh Shon) Résumé of two Papers on Sun-spots:—“On the Form of the Sun-spot Curve,” by Prof. Worr; and “On the Connexion of Sun-spots with Planetary Configuration,” by M. Fritz. By B.Lopwy. ... . . 392 For continuation of Contents see 4th page of Wrapper. CONTENTS—(continued). March 30, 1871. ‘PAGE i Experiments in Pangenesis, by Breeding from Rabbits of a pure variety, into whose circulation blood taken from other varieties had previously been largely transfused. By Francis Gatton, F.R.S. ... . . . . . . 393 II. Contributions to the History of Orcin.—No. I. Nitro-substitution Com- pounds of the Orcins. By Joun Stennouse, LL.D., F.R.S., &.. . . 410 List of Presents 418 ERRATA. Page 246, tine 4 from bottom, for 200 lbs. read 2 volts. 2507 2507 Page 287, line 27, for ne ' read v=ne ! 250R -— 15 Page 288, line 29, for Q=C. E U ee | R PEE 250R : read Q=C Foes ZUR | Ren708. Page 324, 13 line from bottom, for arterial read cardiac. Correction to W.H.L. RussEty’s Paper on Linear Differential Equations, 4c 126. The expression for Q, page 283, should be An An=—1 Q=... SS) Seo ce ate PEAS gol MOREA ot, The process for ascertaining the value of the integral Erz Ge my —a)rA-1 ie (2—B)eF(e—y)rt1 is erroneous, but how the mistake occurred I cannot now tell.—W. H. L. R. TAYLOR AND FRANCIS, RED LION COURT, FLEET STRERT. PROCEEDINGS OF THE ROYAL SOCIETY. VOL. XIX. No. 128. CONTENTS} 2 Lol April 20, 1871. PAGE I. Note on the crcumstances of the Transits of Venus over the Sun’s Disk in the years 2004 and 2012. By J. R. Hinp, E.R.S. . II. On the Existence and Formation of Salts of Nitrous Oxide. By Epwarp Divers, M.D. se Meer ee ee ae cam P eR at eS RE of: III. Research on a New Group of Colloid Bodies containing Mercury, and cer- tain Members of the series of Fatty Ketones. By J. Emerson REYNOLDs, Member of the Royal College of Physicians, Edinburgh, Keeper of the Mineral Department, and Analyst to the Royal Dublin Society . April 27, 1871. THE BaKkERIAN LECTURE.—On the Increase of Electrical Resistance in Con- ductors with rise of Temperature, and its application to the Measure of Ordinary and Furnace Temperatures ; also on a simple Method of measuring Hlectrical Resistances. By CHARLES WILLIAM SIEMENS, E.R.S., D.C.L. . I. On the Change of Pressure and Volume oS ate ee Chemie Combina- tion. By M. BERTHELOT . ; is oes II. Remarks on the Determination of a Ship’s Place at Sea. Ina Letter to Pro- fessor Stokes. By G. B. Atry, LL.D., &., Astronomer Royal May 4, 1871. I. On the Structure and Affinities of Guyxia annulata, Dunc., with Remarks upon the Persistence of Paleozoic Types of Madreporaria. By P. Manrin Duncan, M.B. Lond., F.R.S., Professor of oo in nee 8 ee London SD ena Re ae For continuation of Contents see 4th page of Wrapper. . 423 - 425 » 431 . 443 . 445 - 448 . 450 CONTENTS--(continued). PAGE II, On the Molybdates and Vanadates of Lead, and on a new Mineral from Leadhills. By Professor Dr. AtBERT ScuRavr, of Vienna ... . . 461 May 11, 1871. I, An Experimental Inquiry into the Constitution of Blood, and the Nutrition of Muscular Tissue. By Wittiam Maxcet, M.D., F.R.S., Senior Assis- tant Physician to the Hospital for Consumption and Diseases of the Chest, IBKOMMPEON ys ws. . 465 II. On Protoplasmic Life. By F. Cracz-Catvert, P.RS . . .. . . . 468 III. Action of Heat on Protoplasmic Life. By ¥. Cracz-Catvert, F.R.S. . 472 HErSrmIMETCRCULSI Meats a, it oe coe ees a oak Se ee eed TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. PROCEEDINGS OF Pb ROYAL SOCIETY. VOL. XIX. No. 129. | og NOX ne CONTENTS. May 25, 1871. PAGE I. On the Temperature of the Interior of the Harth, as indicated by Observations made during the Construction of the Great Tunnel through the Alps. By D. T. AnstTep, M.A., E.R.S., For. Sec.G.8.. . . . . . . . . 461 II. Some Remarks on the Mechanism of Respiration. By F. Lz Gros Crark, F.R.C.S., Professor, of we and ee at the as eee of Sivicons Eero tomate: Seok . 486 III. Researches on the Hydrocarbons of the Series C non ity LD. By CC SOERORMEEIMENEEN Foo ae ae 5 sha) Guichen OTe IV. Note on the Spectrum of Uranus and the Spectrum of Comet I., 1871. By Winner Eucemens, UED., D.C: V.PReS. 0 oo. a a 488 V. On a New Instrument for recording Minute Variations of Atmospheric Pressure. By WILDMAN WHITEHOUSE, F.M.S. &.&. . . . ... .. ADT June 8, 1871. Wlection of Hellows .<-: . .-. Sal aie as at cane a Pam aes cate eC weet . 494 June 15, 1871. TI. On the Fossil Mammals of Australia.—Part V. Genus Nototherium, Ow. Papa O La Rug OWEN eM ce Sete) mm att Eee vey epee) oN he Slay re . 494 II. On Cyclides and Sphero-Quartics. By Joun Casry, LL.D., M.R.LA.. . 495 TIE. On a Law in Chemical Dynamics. By Jonn Haxz Guapstons, Ph.D., Heo, and ALERED Ripe Hee See as es a ee eth er ee oh) de te AOS ITV. On the Organization of the Fossil Plants of the Coal-measures.—Part IT. Lepidodendra and Sigillarie. By W. C. Witiiamson, F.R.S., Pro- fessor of Natural History in Owens College, Manchester . . . . . 500 Y. Contributions to the History of the Opium Alkaloids.—Part II. On the Action of Hydrobromic Acid on Codeia and its derivatives. By C. R. A. Wricut, D.Sc., Lecturer on Chemistry in St. cae s Hospital Medical She Suri eeryrnies are 9! For continuation of Contents see 4th page of Wrapper. CONTENTS—(continued). PAGE VI. On the Measurement of the Chemical Intensity of Total Daylight made at Catania during the Total Eclipse of Dec. 22,1870. By Henry E. Rosco, ety oranda’ Bee PHORPEY HRS. be cols. oye) wei 0) Set tar wn eee 6 eo: VII. On the Calculation of Euler’s Constant. By J. W. L. GuaisHer, B.A., eR At Oem MMe me rsee Ro cE SP) oan Luh epee wa whe abe reaat aa, on Oa VIII. Records of the Magnetic Observations at the Kew Observatory. No. 1V.— Analysis of the principal Disturbances shown by the Horizontal and Ver- _ tical Force Magnetometers of the Kew Observatory from 1859 to 1864. By General Sir Epwarp Sapine, K.C.B., President. . . .-. . . . 524 IX. Amended Rule for working out Sumner’s Method of fi ee a ee Place. By Professor Sir Wittiam THomson, F.R.S. . . . . - . 524 _ X. On Linear Differential Equations.—No. V. By W.H.L. Russert, F.R.S. 526 XJ. On the Undercurrent Theory of the Ocean, as propounded pee recent ex- plorers. By Captain Spratt, C.B.,R.N..F.RS. 2. 2. . eee OL XII. On the Physical Principles concerned in the passage of Blood-corpuscles through the Walls of the Vessels. By Richarp Norris, M.D., Pro- fessor of Physiology, Queen’s College, Brmingham. . .. . . . . 556 JOEL) GL TESGE (1 iG roamed Ramage SNe Ura eS, Coan ere NUS rg curva ver anND ere PES are Sah Oe Mie a wee Sw Me age tet pO ao ee apa Oe Obituary Notices :— LSP ONT: Aub ENO WERE DEE s Ose mate hn kk ak ae Get eer ba Va Se ee) es IUIEGRMUIGETGUNEN SC Vie ae ves dae es ed Ro DOP ee neem Nore, p. 526. I did not perceive till the eve of publication that L,,=0; this will give as the equation ° : di € m—1 - : to determine Q simply, L, as +L, d = mee Q Oe gr ot ue NSIS d — Q 220) W. H. L. R.—July 31, 1871. NOTICE. With the commencement of Vol. XX. the Annual Subscription for the Proceedings of the Royal Society will be Twelve Shillings. > TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. Hera oe pei - i / — or ‘ . | siNGhian INSTITUTION LIBRARIES UT 3 9088 01 305 9779