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Abed Pee: 6 peodew eters : Crete Ak u ed swerbens as toad Wh die ene wre tet Honing sel wes bai brinthy oe at sy fad “« bape ores - dhe mf i ; me! : , oral 1K AC 1a Fe i PROCEEDINGS OF THE ROYAL SOCIETY OF LONDON. From March 3, 1892, to May 19, 1892. VOL. LL. eae cOi * AN re / iss : ) | , \ \ . yy, > >< s | Keg oun --9007 A NSONIAN DES NAN DE LONDON: HARRISON AND SONS, ST. MARTIN’S LANE, Printers in Ordinary to Her Majesty. MDCCCXCII. LONDON HARRISON AND SONS, PRINTERS IN ORDINARY TO HER MAJESTY, ST. MARTIN’S LANE. CONTENTS. EVOL. LI. No. 308.--March 3, 1892. Page Certain Correlated Variations in Crangon vulgaris. By W. F. R. Weldon, M.A., F.R.S., Fellow of St. John’s College, Cambridge, Pro- fessor of Zoology in University College, London ......... cu eessesseeseeeseeeeeee 2 An Experimental Investigation of the Nerve Roots which enter into the Formation of the Brachial Plexus of the Dog. By J.S. Risien Russell, M.B., M.R.C.P. (From the Physiological Institute of Berlin and the Fe¥ Pathological Laboratory of University College, London)................04 mer 2 The Influence of the Kidney on Metabolism. By J. Rose Bradford, M.D., D.Sc., Fellow of University College, London, Assistant Professor of Clinical Medicine at University College, Grocer Research Scholar. (From the Physiological Laboratory of University College, London)... 25 a céh ancnenanesiiansanveunanebnsamaxseaunonds duce lon -deeutdesessoveek 40 March 10, 1892. BakeriAn Lecture.—On the Grand Currents of Atmospheric Circulation. By James Thomson, LL.D., F.R.S., Emeritus Professor of Civil En- gineering and Mechanics in the University of Glasgow. [Plate 1] .... 42 re oe de ssn Landen sone nacd ons dade cece voteetoneis¥deesenvauventeever 46 March 17, 1892. Dynamo-Electric Machinery. By J. Hopkinson, F.R.S.,and E. Wilson 49 On the Clark Cell asa Standard of Electromotive Force. By R. T. Glaze- brook, M.A., F.R.S., Fellow of Trinity College, and S. Skinner, M.A., Christ’s College, Demonstrator in the Cavendish Laboratory, Ram a 1400 lines per sq. cm. The represents an induction of difference between ordinates at 320° and at 230° is 2:0; hence, the difference of induction is actually 2800. Theoretically, we have 2emC _ 31x104x11°4 : : ss = fs Td = 2666, as against 2800 actually observed. eee eee ee eT bi Pisa a ea In Diagram No. 4, No. 1 machine is a generator. The total field 52 1 = 504% jog < 10° = 3:97x10° lines. The area of the diagram is 3°9 90°9 sq. cm., and therefore an ordinate of 1 em. = 90-9 * 108 = 4°37 x 10* lines in 10°. Hence, an ordinate of 1 em. represents an induc- 4°37 x 10° tion of = 639 lines per sq. cm. The difference between ordinates at 50° and at 140° is 4°5 ; hence, the difference of induction 2 +x104x 12°9 is actually 2877. Theoretically, we have ee = se = 3010, as against 2877. In Diagram No. 5, No. 2 machine is a motor. The total field G2" Sy 1 ~~ 104 * 123 x 10° = 4°96 x 10° lines. The area of the diagram is | H i | | f | H H | ! a f t u H | ae 1 an aera o, x | | | i | 310° 260°2 2 « ale : 4°96 112°2 sq. cm., and therefore an ordinate of 1 cm. = 1199 * 10 == 4-42 x 104 lines in 10°. Hence, an ordinate of 1 cm. represents an in- 4°42 duction of 633 * 10* = 647 lines per sq.cm. The difference between ordinates at 323° and at 233° is 4°2; hence, the difference of induction 2emC 34 12 is actually 2718. Theoretically, we have 7 ic = Po = 2870, as against 2718 actually observed. At page 345 of the paper on Dynamo-Hlectric Machinery it is shown that —1 Js 4mC: 1+—— 4 mC ai, = F(4 Mist | ; where I = F'(47nc) is the characteristic curve when C = 0, and d is the lead of the brushes. The following is an endeavour to verify this formula. The potentials both upon the magnets and upon the brushes were taken by a Siemens’ voltmeter, and are rough. The speeds were taken by a Buss tachometer, and there is some uncertainty about the precise lead of the brushes, owing to the difficulty in determining the precise position of the symmetrical position between the fields, and also to the width of the contacts on the commutator. : It was necessary, in order to obtain a marked effect of the armature reaction, that the magnet field should be comparatively small, that the current in the armature should be large, and the leads of the brushes should be large. The two machines had their axles coupled so that No. 1 could be 58 Dr. J. Hopkinson and Mr. E. Wilson. [ Mar. 17, run as a generator, and No. 2 asa motor. The magnets were in each ease coupled parallel, and excited by a battery each through an adjustable resistance. The two armatures were coupled in series with another battery and the following observations were made :— Potential on Potential on | Speed per| Currentin | Lead of magnets in volts. brushes. minute. ampéres. brushes. No. 1 24.—24, 66—67 880 102—103 26° No. 2 29—29 86—84 880 102—103 29° | From which we infer :— Current in Corrected potential Total induction | ee i Arne. for resistance of I ag eae armature. No. 1 1°78 8,900 70°8 2°30 x 10° No. 2 2°15 10,750 80°7 2°65 x 10° As there was uncertainty as to the precise accuracy of the measure- ments of potential, it appeared best to remeasure the potentials with no current through the armature with the Siemens’ voltmeter placed as in the last experiment. Hach machine was theretore run on open circuit with its magnets excited, and its potential was measured. Potentia] on magnets Potential on Speed per Potential at in volts. brushes. minute. 880 revs. No. 1 25—25 90—90 880 90-0 No. 2 28—28 79—80 715—710 98 °2 From which, since the formula is reduced to A I = = (47nc—4dmC), 2l, the characteristic being practically straight, we infer :— ] 59 a a ee a 90T X 89-% 90T * 06'S 0626 006122 O9FT @ ‘ON 90T X 18-3 OT X T'S 98S4 OOL66T FIST T ‘ON 1% a a : z g d x OU —( — ULF) i . —IULE : f 16 : x. oy — 4 ‘Quy Ma (Sunt Ma Quy UNG oy I- QUIN “i... - +... - .. S e = S s Z a 2 OOSEPF = 2 guy — 0666 = —— Ss Ay [Bae Qu F 8 GON FOF G.0 = X ‘| GON wlOn cp.07==. XY Ry § —: LOYJAINF OAVY 9 AA S Ss . Q OT x 08- L-TOL 63 gOL X 28-3 P98 PS ‘(ounp) T = T ‘soysnaq ‘sqouseuL WoTPONpUyT UO [BIJUO4OT UO [BIZUeJOT ms NI oe. L D rs 60 Messrs. R. T. Glazebrook and 8. Skinner. [Mar. 17, It has already appeared that experiment gives for I in No. 1 2°3x 10°, and in No. 2 2°65x10°. The difference is probably due to error in estimating the lead of the brushes, which is difficult, owing to uncertainty in the position of the neutral line on open circuit. Ii. “On the Clark Cell as a Standard of Electromotive Force.” By R. T. Guazesroox, M.A., F.R.S., Fellow of Trinity College, and 8S. Sxmvner, M.A., Christ’s College, Demon- strator in the Cavendish Laboratory, Cambridge. Received February 17, 1892. (Abstract. ) The paper consists of two parts :— In Part I an account is given of experiments on the absolute electromotive force of a Clark cell. This was determined in the manner described by Lord Rayleigh (‘ Phil. Trans.,’ 1884) in terms of a known resistance and the electro- chemical Guan of silver. | The resistance used was a strip of platinoid about 1 cm. wide and 0-05 cm. thick wound on an open frame. It was immersed in a bath of paraffin oil, and the currents used, varying from about 0°75 to rather over 1:4 ampéres, did not raise its temperature sufficiently to affect the result. It had a resistance of nearly 1 B.A. unit. This was determined in terms of the original B.A. units. As part of the object of the experiments was to test the memorandum on the use of the silver voltameter recently issued by the Hlectrical Standards Committee of the Board of Trade, the large currents mentioned above were purposely employed. The silver voltameters were treated in accordance with the instructions in the memorandum. The standard cell to which the results are referred is one con- structed by Lord Rayleigh in 1883, probably No. 4 of the cells described in his paper already quoted. The results have been reduced on the supposition that 1 B.A. unit is equal to 0°9866 ohm; if we take the number 0°9535* a representing the value in B.A. units of the resistance of a column of mercury at 0°, 1 metre long, 1 sq. mm. in section, the above is equivalent to saying that the length of the mercury column having a resistance of 1 ohm is 106°3 cm. It has also been assumed that the mass of silver deposited in one second by a current of 1 ampére is 0'001118 gramme, and that the coefficient of change of H.M.F. with temperature of a Clark’s cell is 0°00076. This last result has been verified by us in Part II. * This number is the mean of the best recent results. 1892.] The Clark Cell as a Standard of Electromotive Force. 61 An account of nine separate experiments is given in the paper ; the following are the results reduced to 15° C. :— No. of E.M.F. of No. of E.M.F. of experiment. cell. experiment. cell. 1 14341 6 1 +4342 2 1 °4336 7 1 °4342 3 14341 8 1 °4340 t 1 -4340 9 1 4346 5 1 °4340 The mean of these is 1°4341, or, correcting for the rate of the clock, 1:43.42. In Experiment 2 the current in the voltameter was rather un- steady, which may account for the low value; while in Experiment 9 the temperature of the cell was changing somewhat, and our later experience has shown us that the E.M.F. in our standard cell lags very considerably behind the temperature. Still even taking these experiments into account, the results are very close. If we suppose, as seems most probable, for reasons given in the paper, that our cell is No. 4 of Lord Rayleigh’s paper, and that it has retained relative to No. 1 (Lord Rayleigh’s standard) the value it had in 1883, the E.M.F. of his cell No. 1 would be in the units he used 1:4346 volts at 15°. The value found by Lord Rayleigh was 1:4348 volts; thus the two are very close. In the units we have given above, those specified by the Board of Trade, we have finally the result that the E.M.F. of our cell is 1°4342 volts at 15° C. or 1°4324 volts at 62° F. Part II. In the second part of the paper we have investigated some of the sources of error in the Clark cell, and also the effects of small varia- tions in the materials used and the method of their preparation. We have also compared a number of cells set up by different makers. The general result is a very good agreement among cells from very various sources. Cells set up by Lord Rayleigh in 1883 and 1884, Mr. Elder in 1886, Mr. H. L. Callendar in 1886, Dr. Muirhead in 1890, and by Dr. 62 Messrs. R. T. Glazebrook and 8. Skinner. [Mar. 17, Schuster, Mr. Wilberforce, and ourselves during the past year, all agree closely, the variations among them being rarely greater than about 0°0005 volt. The first set of cells, eighteen in number, constructed for the pur- poses of this enquiry were made according to Lord Rayleigh’s instructions, using, however, various specimens of the chemicals. These showed some differences at first, but in the course of about two months they had all, with one exception, settled down to close agree- ment with the standard. The exceptional cell has since become normal. In two of these cells mercury was used which had been taken direct from the stock in every-day use in the laboratory. The H.M.F. of these cells was much too low at first, but it gradually increased, and they are nownormal. The mercurous sulphate appears to free the mercury from certain harmful impurities. Another set of cells were put up, in accordance with the provisional memorandum of the Electrical Standards Committee of the Board of Trade, issued in June last and quoted below. MEMORANDUM ON THE PREPARATION OF THE CLARK’s STANDARD CELL. Definition of the Cell. The cell consists of mercury and zinc in a saturated solution of zinc sulphate and mercurous sulphate in water, prepared with mercurous sulphate in excess, and is conveniently contained in a cylindrical glass vessel. Preparation of the Materials. 1. The Mercury.—To secure purity it should be first treated with acid m the usual manner, and subsequently distilled in vacuo. 2. The Zinc.—Take a portion of a rod of pure zinc, solder to one end a piece of copper wire, clean the whole with glass paper, carefully removing any loose pieces of the zinc. Just before making up the cell, dip the zinc into dilute sulphuric acid, wash with distilled water, and dry with a clean cloth or filter paper. 3. The Zinc Sulphate Solution.—Prepare a saturated solution of pure (“pure recrystallised”) zine sulphate by mixing in a flask distilled water with nearly twice its weight of crystals of pure zinc sulphate, and adding a little zinc carbonate to neutralise any free acid. The whole of the crystals should be dissolved with the aid of gentle heat, ¢.e., not exceeding a temperature of 30° C., and the solution _ filtered, while still warm, into a stock bottle. Crystals should form as it cools. 4. The Mercurous Sulphate-—Take mercurous sulphate, purchased as pure, and wash it thoroughly with cold distilled water by agitation in a bottle; drain off the water, and repeat the process at least twice. After the last washing, drain off as much of the water as possible. Mix the washed mercurous sulphate with the zine sulphate solution, adding sufficient crystals of zinc sulphate from the stock bottle to ensure saturation, and a small quantity of pure mercury. Shake these up well together to form a paste of the consistency of cream. Heat the paste sufficiently to dissolve the crystals, but not above a temperature of 30°. Keep the paste for an hour at this temperature, agitating it from time to time, then allow it to cool. Crystals of zine sulphate 1892.] The Clark Cell as a Standard of Electromotive Force. 63 should then be distinctly visible throughout the mass; if this is not the case, add more crystals from the stock bottle, and repeat the process. . This method ensures the formation of a saturated solution of zinc and mercurous sulphates in water. The presence of the free mercury throughout the paste preserves the basicity of the salt, and is of the utmost importance. Contact is made with the mercury by means of a platinum wire about No. 22 gauge.—This is protected from contact with the other materials of the cell by being sealed into a glass tube. The ends of the wire project from the ends of the tube; one end forms the terminal, the other end and a portion of the glass tube dip into the mercury. To set up the Cell. The cell may conveniently be set up in a small test-tube of about 2 cm. diameter, and 6 or 7 cm. deep. Place the mercury in the bottom of this tube, filling it to a depth of, say, 15cm. Out a cork about 0°5 cm. thick to fit the tube ; at one side of the cork bore a hole, through which the zine rod can pass tightly; at the other side bore another hole for the glass tube which covers the platinum wire; at the edge of the cork cut a nick through which the air can pass when the cork is pushed into the tube. Pass the zine rod about 1 cm. through the cork. Clean the glass tube and platinum wire carefully, then heat the exposed end of the platinum red hot, and insert it in the mercury in the test-tube, taking care that the whole of the exposed platinum is covered. Shake up the paste and introduce it without contact with the upper part of the walls of the test-tube, filling the tube above the mercury to a depth of rather more than 2 ‘em. Then insert the cork and zinc rod, passing the glass tube through the hole pre- pared for it. Push the cork gently down until its lower surface is nearly in contact with the liquid. The air will thus be nearly all expelled, and the cell should be left in this condition for at least twenty-four hours before sealing, which should be done as follows :— Melt some marine glue until it is fluid enough to pour by its own weight, and pour it into the test-tube above the cork, using sufficient to cover completely the zinc and soldering. The glass tube should project above the top of the marine glue. The cell thus set up may be mounted in any desirable manner. It is convenient to arrange the mounting so that the cell may be immersed in a water-bath up to the level of, say, the upper surface of the cork. Its temperature can then be determined more accurately than is possible when the cell is in air. . These cells, as the tests given show, have been good from the first, and, indeed, we have not had any difficulty with any of the cells in which the instructions of this memorandum have been followed. The mercury used had been distilled in the laboratory, the zines were supplied as ‘“‘ pure” by Messrs. Harringtons, of Cork, while the zinc and mercurous sulphates came from Messrs. Hopkin and Williams. The numbers in the table show the differences between the cells and the standard; the unit is 0°00025 volt. [Mar. 17, Messrs. R. T. Glazebrook and 8S. Skinner. 64 # ST 41nG| "2 Aine “4J0A GZO00-0 SI UN oI, 0 0 0 0) I I 0 T O L if Sie Sins | sais T I 0) @) 0 if T Ls ES 6 o— | 0 3) 0 0 0 r= LS ST 6-6 v- PL y-9L G- 41 v- ot | got 81 g- PT = of "L109 | "PL AON |S “40N |°2s SY | ‘PT “Suny | ‘OT Sny| ‘9 ‘Bny |-og 4mpe| *g sung | -g oung “PIBPULIG GY} PUL S][OD JO Jog B UeoM4oq SeoUaJEyIG e= gy ° (= 6, y— TZ ‘ON ae 3 “aiuommataeae Speen Se ae 1892.] The Clark Cell as a Standard of Electromotive Force. 65 Tt may be well to explain the purpose of some of the precautions advised in the circular. The mercurous sulphate, as ordinarily pur- chased, contains some mercuric sulphate. When this is moistened with water it is resolved into a yellow basic mercuric sulphate (turpeth mineral) and a soluble acid mercuric sulphate. The first, at any rate in moderate quantities, does not affect the H.M.F.; the latter greatly hinders it from attaining the proper value. Repeated washing, however, removes most of this soluble salt. The paste, when made, is shaken with mercury to remove any traces of the acid sulphate which may be left, for the acid mercuric sulphate attacks the mercury and forms mercurous sulphate. Careful precautions are necessary to ensure that the solutions should be saturated with both zinc and mercurous sulphates, but the solu- tions should not be raised in temperature above 30°C., for the zinc sulphate may then crystallise out in the wrong form. The proper crystals have the composition ZnSO,.7H,O, and are rhombic. But while we have had no serious difficulty with any of the cells prepared in accordance with the last form of the memorandum, some of the other cells we have set up have led to some interesting results. Two sets of cells were put up with great care by Mr. Wilberforce in March and April. One of us (S. 8.) set up some cells in the same way about the same time. The solutions were prepared from very pure materials, following Lord Rayleigh’s instructions. The zine sulphate was remarkably free from acid, and it appeared as if the results ought to be good. In the first set, Nos. 36—41, the E.M.F. was too low. At the end of a month it was much too low, about 0°005 volt, and Mr. Wilber- force noticed that a duli-grey deposit covered the zincs; he therefore removed them and scraped off this deposit, when, on replacing the zines, the cells were found to have approximately the normal H.M.F. ; they have continued nearly normal since. The next set, Nos. 42—47, - were very good when first set up, but the EH.M.F. soon fell rapidly, until at the end of a month they were nearly 0:01 volt too low. The grey deposit again was formed over the zinc. Some of these cells were left untouched till August, by which time the E.M.F. had recovered somewhat, being then about 0°005 too low. Others had been treated by removing the zines and replacing them by amalga- mated zincs. In August some experiments were made on the unal- tered cells, which showed conclusively that it is necessary that the surface of the zinc should remain paght if consistent results are to be obtained. This bright surface may be secured by amalgamating the zine, but we are not yet sure that this alone is effective, for it seems possible from various observations that some action which results in the VOL. LI. F 66 Clark Cell as a Standard of Electromotive Force. |Mar. 17, amalgamation of the zinc must go on in the cell to enable it to reach the steady state, and that it may not be sufficient to introduce amalga- mated zincs. On this and some kindred points, however, we are still experimenting. The grey deposit can be shown to be mainly mercury in a state of very fine division. There are some indications that a sight acidity in the solutions is of use in promoting amalgama- tion. We have verified repeatedly an observation of Dr. Hopkinson’s that the E.M.F. of a bad cell changes considerably if the cell be slightly shaken, while that of a good cell is not affected. The paper also contains an account of some experiments on the coefficient of change of E.M.F. with temperature. The value found is 0°000755 per 1° C., practically the same as that given by Lord Rayleigh. In this connexion we may mention the important obser- vation that when the temperature is rising, even although the rise be only a few degrees, the E.M.F. of the cell may—especially if the cell be large—lag very considerably behind the temperature. On one occasion in which the temperature rose by some 5°C.in about a week, the H.M.F. of our large cell at the end of the week corresponded to a temperature nearly 3° lower than that given by a thermometer in the bath with the cell, being about 0°0027 volt too high. In this case a thick cake of crystals had formed on the top of the more solid portion of the paste, and the zinc sulphate solution only attained the state of saturation corresponding to the temperature by very slow degrees. Mr. Carhart and Mr. Swinburne have called attention to the difficulties which thus attend the practical use of the cells. They are to some extent met by using small cells. The paper also describes a new form of portable cell which may be turned into any position without harm. Hxperiments have also been made on the mercury chloride standards described by Von Helmholtz. A set of these has been constructed which has an H.M.F. of very nearly 1 volt. A form of standard due to Gouy, in which oxide of mercury is used, has also been examined. The H.M.F. of these cells prepared with yellow oxide is, we find, 1°381 volts, and when prepared with red oxide 1°388 volts. By the kindness of Major Cardew-several of our cells have been compared with the standards of the Board of Trade. The differences are very small, being about 0:0003 volt. The average of the Board of Trade cells is less than our standard by about this amount. The Board of Trade possess seventy-two cells, and Mr. Rennie, Major Cardew’s Assistant, informs us that the greatest difference between any two of them is under 0:0007 volt. It will be seen from the table given that, while the cells there considered are on the average about one of our units above our standard, they are rather over two of such units above the Board of Trade cells, 1892.] On the Nerve-roots of the Lumbo-sacral Pleaus. 67 Thus our standard exceeds the cells of the Board of Trade by rather over one of our units, or about 0°0003 volt. Tf we take the E.M.F. of our standard as 1°4342 volts at 15°, the cells of the Board of Trade average in H.M.F. about 1:4339 volts at 15° C., or 1:4321 volts at 62° Fahr. III. “Note on the Functional and Structural Arrangement of Efferent Fibres in the Nerve-roots of the Lumbo-sacral Plexus.” (Prelimmary Communication.) By C. 8. SHER- RINGTON, M.A., M.B., &c. Communicated by Professor M. Foster, Sec. B.S. Received March 14, 1892. | At the commencement of some observations on the reflex mechan- isms of the spinal cord in Macacus rhesus, difficulties were en- _ countered which made it desirable to attempt for that animal a some- what particular examination of the distribution of the efferent and afferent spinal nerve-roots belonging to the lumbo-sacral plexus. The present communication has reference to the distribution of the efferent fibres of the roots. Reil,* Scarna,+ A. Monro,t and Soemmering§ all paid considerable attention to the arrangement of the root-bundles in the limb plexuses, but physiological work upon the subject commenced with Van Deen,|| J. Miller,f{ and Panizza.** The former two gave an anatomical significance to the plexus, the last a physiological. At Miiller’s suggestion, renewed research was undertaken by H. Kronenbergtt in 1835. Kronenberg confirmed Miiller’s observations as to the in- dividual inconstancy of the contribution made by any spinal root to the nerve cords of the plexus; he also concluded that the excitation of a single nerve-root before its entrance into the plexus produces contraction of almost all the muscles of the limb; and that the arrangement is intended to protect against fatigue. Later, Hekhardt,t? working in Ludwig’s laboratory, arrived at somewhat similar conclusions. He stated that a great number of muscles obtain nerve-fibres each of them from several nerve-roots; that there is a good deal of individual variation; that when a nerve-root is ‘De Nervorum Structura,’ p. 14. ° “De Gangliis et Plexibus.’ ‘Observations on the Structure and Functions of the Nervous System,’ p. 34. ‘ Anatom.,’ Pars Vta. ‘De Differentia et Nexu inter Nervos Vite Anim. et Organ.,’ Leyden, 1834. ‘Physiol. des Menschen,’ vol. 2, p. 586. ** © Annali Universali di Medicina.’ +t Essay (‘De Struct. et Virtut. Plexuum Nervorum’), Berlin, 1836. ti ‘Zeits. f. Rat. Med.,’ vol. 7, p. 306, 1849. = MHrtt+—-+ * * = ¥F 2 68 Mr. C. 8. Sherrington. [Mar. 17, unusually thick the additional fibres in it are not all of them, perhaps none of them, used to supply the muscles usually supplied by the root, but are used to supply altogether other muscles not usually supplied by the roots ; that the distribution of the fibres of a root is not to one group of muscles, but is to several groups, which are often not related to each other in function ; that antagonistic groups are often supplied by one and the same root. Three years after the experiments by Eckhardt, and also under Ludwig, Peyer’s* experiments on the brachial plexus of the rabbit were made. As Krause, in 1861,f repeated Peyer’s work on the same limb and the same species, the results of both may be here referred to: together. The muscles of the limb each receive nerve-fibres from two, in some cases three, spinal roots; usually the contraction of a muscle on excitation of the spinal roots innervating it is obviously different in degree for each root: the same spinal root does not always supply in different individuals the same muscles; the further the position of a spinal root from the head, the nearer the muscles it supplies to the distal end of the hmb; the peripheral trunks of the lhmb plexus are themselves plexuses of root-bundles. In 188] Ferrier and Yeot confirmed the above results in experiments on the spinal roots of the monkey. In addition to their experiments on the brachial plexus, they performed four complete experiments on the lumbo-sacral roots. Unlike Kronenberg, Eckhardt, and others, they do not seem to have met with any variation in the results obtained. They revived the view that the efferent distribution of each spinal nerve is based on its phy- siological function, and that the movement resulting from the excita- tion of a root is that of a highly coordinated functional synergism. Some months later Paul Bert and Marcacci§ published experiments on the lumbar roots of the cat and dog. They concluded that (1) each root produces a coordinate movement, and consists of fibres function- ally associated; (41) when a muscle is functionally divisible its root-. supply is multiple. | In 1883 Forgue and Lannegrace|| published a research on the limb plexuses of the cat, dog, and monkey. The ‘Comptes Rendus ’€ of » the following year contain their reports. As to the lower limb, their account is prefaced by a remark that the highest lumbar root of man is tripled in the dog and monkey. What species of monkey was used: is not mentioned in the ‘Comptes Rendus.’ In Macacus the 5th lumbar root is analogous not to the 3rd of man, but to the 4th, and. * ‘Arch. f, Rat. Med.,’ IT, vol. 4, p. 67, 1853. + ‘Beitrage zur Anat. der Oberen Extremitiit,’ 1861. t ‘Roy. Soc. Proc.,’ 1881. § ‘Soc. de Biol.,’ July, 1881. || ‘Gaz. Hebd. des Sci. Médic. de Montpellier, 1883. { ‘Comptes Rendus,’ 1884, vol. 98, pp. 829, 685, 1068. 1892.] On the Nerve-roots of the Lumbo-sacral Plexus. 69 to the 6th of the dog. The chief of their conclusions, drawn from examination of both limbs, are :—The majority of muscles are innerv- ated by several roots. Excitation of a root determines in the muscles which it supplies a total, not a partial, contraction. The tributary fibres of the root are disseminated through the muscle supplied by it, and not ‘‘ cantonnées ” in a special zone of it. Hach root has a mus- cular distribution almost absolutely constant in the animals of its own species. The functions of analogous roots differ very little in different mammalian species. Hach root supplies muscles of very various, often of antagonistic, action. Hxcitation of a root gives a combined movement, but an artificial, not a functional. The roots that pass furthest into the member occupy the lowest position in the cord. The innervation of the two planes of flexors and extensors is not always symmetrical. The superficial layers are supplied before the deep. Herringham,* by minute dissection of the human brachial plexus, and, therefore, under disadvantage from inability to distinguish clearly between afferent and efferent fibres, arrived nevertheless at facts and conclusions of great importance. He found much indi- vidual variation, but evidence of certain “laws.” Thus: any given root-fibre may alter its position relative to the vertebral column, but will maintain its position relative to other fibres; of two muscles, or two parts of a muscle, that which is nearer the head end of the body tends to be supplied by the higher, that nearer the tail end by the lower, root ; of two muscles, that nearer the long axis of the body tends to be supplied by the higher, that. nearer the periphery by the lower, root; of two muscles, that nearer the surface tends to be supplied by the higher, that further from it. by the lower, root. Recently Langley,+ in the course of a paper on the sweat nerves to the foot of the cat, refers to the movements of the limb produced by excitation of roots of sciatic plexus in that animal. He desired to ascertain whether the variation, which he finds considerable in the distribution of the sweat nerves (sympathetic system), has a correla- tive in the distribution of the nerves to the limb muscles. Like Kronenberg, Eckhardt, and Peyer, he finds that the movements re- sulting from stimulation of the same nerve-roots are not uniform, and that the want of uniformity goes hand in hand with want of uniformity in the root composition of the plexus, just such as displayed in Her- ringham’s dissections. My own observations have been made, during the past three years, chiefly on the lumbo-sacral roots of Macacus rhesus; also on the trog, rat, rabbit, cat, and dog, chiefly for the sake of comparing those types with Macacus. The animals have been deeply anesthetised * ‘Roy. Soe. Proc.,’ 1887. + ‘Jl. of Physiol.,’ September, 1891. 70 _. Mr. C.-8. Sherrington. Var with chloroform and ether. The excitations of the roots have been made in the spinal canal; the single root, or a component filament from it, has been isolated in the case of the lower roots of the cat and monkey, to a length 5, 6, or 7 cm., and lifted up by a silk ligature on to small platinum electrodes sheathed almost to the points. Series of weak induced currents have been used for excitation, one pint Daniell being in the primary of the ordinary physiological induc- torium (R. Ewald’s pattern). The secondary coil has usually been at a distance from the primary somewhat more than twice that at which a current was detectable by the tongue. Use has also been made of absolutely minimal stimuli, and largely of mechanical stimuli. For certain purposes, stimulation by quite strong electrical excitation has been used. In these experiments it became clear that the frequency of indi- vidual variation, as regards the anatomical and physiological consti- tution of the efferent roots of the lumbo-sacral region, was great enough to demand the recognition of a “pre-axial” and a “ post- axial”? class of innervation for each muscle and movement. By pre-axial class of innervation is meant that the roots connected with the muscles and the movements are more pre-axial than the roots connected with the same muscles and the same movements in the post-axial class of innervation. Thus, in the frog there is a pre-axial class of innervation for the hind limb, in which, for instance, the viith spinal root, as well as sup- plying the antero-internal thigh muscles, supplies the muscles on the front of the leg (tibialis anticus). There is a post-axial class in which the pretibial muscles are supplied by the vilith and ixth roots only. The post-axial class as measured in this way is the more usual. This. may be merely because the above criterion, found convenient for dis- tinguishing in any individual case the direction which the variation has taken in it, does not coincide with the mid point about which individual variation in the species is really oscillating. _ By “pre-axial”’ and “‘ post-axial ” classes it is not intended to imply that in the range of individual variation one case is not more fre- quently exemplified than are others; it is only meant that so frequent is the variation that no one caseis sufficiently predominant to warrant the choice of it as a “normal” type, and that therefore it is more correct to treat the composition of the plexus of the species as mul- tiple and then for convenience divide it into classes. I have thought two classes, ‘‘ pre-axial”’ and “ post-axial,” a distinction sufficient to observe’ in my present description. Just as in the frog, so in the other animals employed, the “‘ pre-axial ” and “ post-axial” class of the plexus have both been exemplified by individuals of each species. In the rat, rabbit, cat, and dog, the 9th subthoracic root sometimes sup- plies the intrinsic muscles of the foot (post-axial innervation), some- 1892.| On the Nerve-roots of the Lumbo-sacral Plexus. 71 times does not, the 8th taking its place (pre-axial class of innervation) as well as supplying other fibres also. In the cat, in my own experi- ments, the post-axial class, as measured by the above standard, has contained a rather larger number of individuals (twenty-two out of thirty-nine).* In experiments on Macacus, also, it early became clear that the types of innervation of the limb-muscles by the spinal roots are con- veniently dealt with as two classes. In fifty-two individuals the reactions obtained place the majority (thirty-one) within a pre-axial class, the broad features of which are as follows :— Pre-axial Class of Innervation. No. of the root excited. Movement produced. lst Subthoracic.. Retraction of abdominal wall, near umbilicus in front. 2nd = .. Retraction of lower part of abdominal wall, flexion of hip, with some eversion, drawing up of testicle (stronger than with 3rd). ord ‘3 .. Retraction of lowest part of abdominal wall, drawing up of the testicle, flexion at hip, with marked rotation of thigh outwards and some adduction, some extension of knee. Ath = .. Flexion at hip, extension at knee, adduction of thigh, eversion of thigh. Sth o .. Flexion at hip, extension at knee, adduction of thigh, strong flexion at ankle, drawing up of outer edge of foot, flexion of hallux and digits. 6th 93 .. Extension at hip, adduction of thigh, flexion at knee, extension at ankle, rotation of leg inwards, lifting of outer edge of foot, flexion of digits and hallux at terminal joint with (sometimes) adduction. 7th 4 -. Extension at hip, with slight rotation out- ward of the thigh, flexion at knee, extension at ankle, flexion of digits and hallux with adduction of hallux, depression and adduc- tion of root of tail, closure of anus. Sth - .. Extension at hip, with slight rotation outward of the thigh, flexion at knee, extension at ankle, strong flexion and adduction of hallux, flexion of digits in “interosseal ” position, closure and protrusion of anus, root of tail adducted and depressed, perineum pushed down. * This agrees with the observations by Langley, loc. cit. No. of the root excited. 9th Subthoracic .. 10th No. of root excited. lst Subthoracic.. 2nd cS 3rd Z 4th Fe 5th 4 6th a Mr. C. 8. Sherrington. [Mar. 17, Movement produced. Adduction of root of tail, which is drawn toward the side stimulated. Proximal half of tail drawn toward side stimulated. Muscle thrown into action. Quadratus lumborum, psoas parvus, external oblique, internal oblique, transversalis. Quadratus lumborum, psoas magnus, cremaster, external oblique, internal oblique, trans- versalis. Psoas, cremaster, iliacus, external oblique, in- ternal oblique (lower part only), trans- versalis, pectineus, adductor longus, sarto- — rlus (upper part especially), vastus internts, and obdurator externus slightly. Psoas, iliacus, pectineus, adductor longus, sar- torius (lower part especially), vastus im- ternus (> vastus externus), crureus, ob- turator, rectus femoris, vastus externus, gracilis. Gracilis, vastus externus (> vastus internus), rectus femoris, vastus internus, crureus, adductor magnus, semimembranosus, tibi- alis anticus, tensor vagine femoris, per- oneus longus (occasionally strongly), flexor longus hallucis (slight), flexor longus digi- torum (slight), tibialis posticus (slight), extensor longus digitorum, extensor proprius hallucis. Tibialis anticus, extensor longus digitorum, extensor hallucis, peroneus longus, peroneus brevis, extensor brevis digitorum, gastro- cnemius external head (> internal head), internal head, tibialis posticus, flexor longus digitorum, flexor longus hallucis, semimem- branosus (> semitendinosus), semitendiuo- sus, biceps (shght, chiefly in deep portion), adductor hallucis, flexor brevis digitorum, adductor hallucis (sight), adductor minimi digiti, soleus (slight), plantaris, popliteus, gluteus medius, quadratus femoris. Tibialis anticus, extensor longus digitorum, extensor proprius hallucis, peroneus longus, 1892.] On the Nerve-roots of the Lumbo-sacral Plexus. 73 No. of root excited. Muscle thrown into action. slight (< peroneus brevis), peroneus brevis, gastrocnemius external head, internal head, plantaris, tibialis posticus, flexor longus digitorum, soleus, flexor longus hallucis, extensor brevis digitorum, flexor brevis digi- torum, adductor hallucis, adductor minimi digiti, flexor accessorius, flexor brevis hal- lucis, flexor brevis minimi digiti, interossei and. lumbricales, obturator internus, quad- ratus femoris, gemelli superior et inferior, pyriformis (the larger part of, especially the lateral part), deeper part of sphincter ani, semitendinosus, semimembranosus, biceps, adductor magnus (part of), poplitens, gluteus medius. Sth Subthoracic.. Biceps (< than semimembranosus), semitendi- nosus (< than semimembranosus), semimem- branosus, gluteus maximus, gluteus medius, gastrocnemius internal head (< than exter- nal), external head, soleus, adductor hallucis, flexor accessorius, adductor minimi digiti, adductor hallucis, obturator internus, quad- ratus femoris (slight), gemelli superior et inferior, pyriformis (small part, chiefly me- sial), sphincter ani, flexor brevis hallucis, flexor brevis minimi digiti, lumbricales and interossel. 9th a .. Sphincter vagine, obturator internus (slightly). The remaining twenty-one individuals formed a “ post-axial”’ class, with the following broad characters in common :— Root. Movement. lst Subthoracic.. Retraction of abdominal wall. (1st lumbar) 2nd e . Retraction of lower part of abdominal wall, drawing up of testicle, slight flexion at hip. ord i .. Contraction of lower part of abdominal wall, drawing up of testicle (stronger than with 2nd), flexion at hip, slight flexion at knee, slight rotation outwards of thigh. 4th 3 .. Drawing up of testicle (slight) ?, contraction of lower part of abdominal wall, flexion at 4 Mr. C. S. Sherrington. [Mar. 17, Root. Movement. hip, with adduction of thigh, extension at knee, slight rotation outwards of thigh. Sth Subthoracic.. Flexion at hip, with adduction of thigh, exten- sion at knee, drawing up of inner edge of foot, with slight flexion at ankle, and slight extension of hallux. 6th ss .. Extension at hip, with adduction of thigh, flexion at knee, flexion at ankle, lifting of outer edge of foot, extension of toes, with adduction of hallux. 7tb : .. Extension at hip, flexion at knee, extension at ankle, tilting of outer edge of foot, flexion of digits, with strong adduction of hallux, depression of root of tail, slight rotation outward of the thigh. Sth i .- Slight rotation outward of the thigh, exten- sion at hip, flexion at knee, extension (very strong) at ankle, strong flexion and adduc- tion of hallux, flexion of digits in ‘“‘in- terosseal ” position, contraction of anus, root ot tail depressed and drawn to side stimu- lated. s .. Shght rotation outwards of the thigh, flexion of digits, perineum pushed down, contrac- tion of anus, abduction of root of tail toward side stimulated. 10th is .. Abduction of root of tail toward side stim- ulated. llth f .- Proximal two-thirds of tail drawn toward side stimulated. 12th is -- Distal half of tail drawn toward side stimu- . lated. 5 13th os -. Tip of tail drawn toward side stimulated. Post-axial Class. lst Subthoracic.. Quadratus lumborum, psoas parvus, external oblique, internal oblique, transversalis. 2nd . -. Quadratus lumborum, psoas magnus, cremaster, external oblique, internal oblique, trans- versalis. 3rd ‘< .. Psoas magnus, cremaster, iliacus, external oblique, transversalis (the lower part only 1892.] On the Nerve-roots of the Lumbo-sacral Plexus. 75 Root. 4th Subthoracic.. Sth i 6th a “ 7th s Sth ss Movement. . of the three latter), pectineus, adductor longus, sartorius. Psoas magnus, iliacus, pectineus, the adductor longus, gracilis (probably the rest of the adductor mass), sartorius, vastus internus, vastus externus, crureus, rectus fem. (slight), obturator externus. Gracilis, adductor longus (slight), tensor vagine femoris, rectus femoris, vastus in- ternus, vastus externus, crureus, tibialis an- ticus, peroneus longus, semimembranosus (these latter only slightly), extensor hallucis (very slight). Part of adductor magnus, tibialis anticus, ex- tensor longus digitorum, extensor hallucis, peroneus longus, peroneus brevis, short (in- trinsic) extensors of the digits, abductor minimi digiti, gastrocnemius (both heads, but slight), popliteus, tibialis posticus, flexor longus digitorum, long flexor of the hallux, soleus, semimembranosus, plantaris, semi- tendinosus, biceps. Adductor magnus, semitendinosus, semimem- branosus, tibialis anticus, extensor longus digitorum, extensor propr. hallucis, peroneus brevis, peroneus longus, plantaris, popliteus, gastrocnemius (both outer and inner heads), tibialis posticus, flexor longus digitorum, soleus, long flexor of the hallux, short ex- tensor (intrinsic extensor) of the digits and hallux, short and accessory flexors (in- trinsic flexor) of the digits and hallux, ab- © ductor minimi digiti, the abductor hallucis, the adductor hallucis, large part of pyri- formis, interossei and lumbricales, obturator internus, quad. fem. and two gemelli. Biceps, semimembranosus, semitendinosus, gluteus medius, gastrocnemius (both heads), soleus, tibialis posticus, flexor longus digi- torum, abductor hallucis, abductor natum, short and accessory flexor of the digits and hallux, adductor of the hallux, interossei and lumbricales, sphincter ani, sphincter vagine, small part of pyriformis, obtu- 76 Mr. C. 8. Sherrington. [Mar. 17, Root. Movement. rator internus, quad. fem. and the two gemelli. 9th Subthoracic.. Short flexor of the digit and hallux, adductor of the hallux, interossei and lumbricales, sphincter vagine, obturator internus, sphinc- ter ani. The results of the experiments are in harmony with those of Hckhardt. Many of the muscles of the limb are supplied by three ‘spinal roots, some by two; one alone, as far as I have yet observed, by a single root only. Individual variation is frequent. Hxecitation of the same spinal root not always throws into action the same muscles, even in individuals of the same species, sex, and approximate age; nor does it always produce the same movement, e.g., flexion at knee followed excitation of 5th root in two individual instances. Analysis of the distribution of the component filaments of a root shows that in different individuals filaments which correspond in absolute position in the nerve-root do not correspond in function. Nevertheless, Herringham’s “‘ Law I” (quoted above) holds good for the outflow of fibres throughout considerable regions of the cord, although a sciatic plexus of the post-axial class may occur in the same individual as a brachial plexus of the pre-axial class, so that in its narrowest sense the “law” is not always applicable to great lengths of the cord. No exception has been found to it in the sense that an efferent fibre pre-axial in one individual to some particular other efferent fibre is ever in any individual of the same species post- axial to it. The distribution of the peripheral nerve-trunks is not obviously different, whether by its root-formation the plexus belong to the pre- axial or to the post-axial class. The peripheral nerve-trunks are, as regards their muscles, relatively stable in comparison with the spinal roots. When the innervation of the limb-muscles is of the pre-axial class, so also is that of the anus, vagina, and bladder; and conversely. The region of outflow from the spinal cord of the fibres destined for a natural group of the limb-muscles, or the representation of a par- ticular movement at a limb joint, is often not conterminous with the origin of the filaments of a spinal root, but has its limits at points within spinal segments, either overstepping or falling short of their boundaries. Thus the outflow to the intrinsic muscles of the sole sometimes has its upper limit placed nearly midway up the region of origin of the filaments of the 6th root. The Jower limit of the out- flow to the calf muscles sometimes lies about two-thirds down the region of origin of the 8th root. Other examples could be cited. The ankle, knee, &c., which seem to be divisions between funda- 1892.] On the Nerve-roots of the Lumbo-sacrai Plexus. 17 mentally distinct portions of the limb, are not regarded as such in the segments of the spinal cord. If the simple movements (flexion, &c.) of the limb-joints be con- sidered individually, the region of representation in the spinal roots of Macacus extends for each into at least three segments of the cord.. The region of representation for each simple movement is about as extended for the small joints (digits) as for the large (hip-knee). The whole region of representation for the movements of the knee is, however, longer (includes more cord segments) than that for the ankle; and that for the hip is longer than that for the knee. This is because the more distal the joint the greater the overlap of the regions of representation in the roots of each of the two opposed. movements at the joint. Of the opposed movements, the one which is in a direction toward the anterior aspect of the limb is always represented the more pre-axially in the spinal roots. In the thigh, the nerve-roots supplying the musculature are none: of them common at once to the muscle groups of the anterior and posterior aspects of the thigh. In the foot and leg the nerve-roots supplying the muscles each supply muscles situated both on the ante- rior and posterior aspects; this is more marked in the case of the foot than of the leg; yet in the former even the musculature of the sole is distinctly post-axial to that of the dorsum. Although there is clear evidence that the nerve supply of the skin of the hallux is pre-axial to that of the 5th digit, my experi- ments have given only equivocal evidence that the musculature of the hallux is pre-axial to that of the minimus; nor is in the thigh the gracilis (lower part) pre-axial to the vastus externus. The mutual relationship of gracilis and vastus externus is as that of rectus abdominis to erector spine in the trunk, 7.e., ventral to dorsal ; the same is probably true of hallux and 5th digit (as regards their musculature). This is in accord with Paterson’s* views of the mutual relationship of the obturator and anterior crural nerves, although not with his extension of a.similar view to the relationship of the internal and external popliteal nerves. The posterior aspect of the thigh and leg afford an important ex- ception to the rule given by Forgue and Lannegrace, and confirmed, as regards the fore-limb, by Herringham, viz., that, of the superficial and deep muscular layers of a region of the limb, the superficial layer is innervated by more pre-axial roots than the deep layer. The reverse holds good for the calf muscles and the hamstrings. The significance of the distribution of the efferent fibres of a spinal root is, as J. Miller suggested, anatomical (based on metamerism,,. &c.) rather than functional (based on co-ordinate action, &ec.). Hx- citation of an entire efferent root produces a combined movement * ¢J1, of Anat. and Physiol.,’ 1887 and 1889. 78 Dr. §. Martin, [Mar. 17, due to the action of many muscles, but there is no safe ground for believing that the combination is of a functional character; the weight of evidence is against this. As to the question whether a muscle, when supplied by several nerve-roots, is supplied by them in such a way that one piece of the muscle is supplied by one root, another by another, although there is certainly great interlapping of regions belonging to the individual roots, I cannot agree with Forgue and Lannegrace when they say, “‘ Hxcitation of a spinal root determines in the muscles which it sup- plies a total, not a partial, contraction.” Simple inspection is enough to convince one, that in the case of some of the larger muscles, ¢.¢., in the thigh and spinal regions, the nerve supply from the individual roots is distinctly partial, that a district of the muscle belongs to this root, another district to that, although always with a large mutual overlap ; striking examples are given by the sartorius, 3rd and 4th (Macacus) sacrococcygeus superior, 7th, 8th, 9th (cat), &c. On the other hand, as the distal end of the limb is approached, the inter- mingling of the root-districts in the several muscles becomes more intimate, and in the muscles of the sole the intermingling of the muscle-fibres belonging to individual nerve-roots is so complete as to baffle analysis, except by the degeneration method. In the sphincter muscle of the anus there is an overlap of the motor dis- tributions of the right and left halves of the body. The sphincter ani is supplied by four nerve-roots, two right-hand, two left-hand. Any three of these may usually be cut through without the anus becoming patulous, or exhibiting asymmetry. Conversely, excitation of any one of the efferent roots supplying it causes contraction of both right and left halves of it. The innervation of the bladder from its right- and left-hand roots, is, on the cther hand, neither in the case of its sympathetic nor its direct spinal supply of a bilateral character. IV. “On the Causation of Diphtheritic Paralysis.” By SIDNEY Martin, M.D., F.R.C.P., Assistant Physician to University Coliege Hospital. Communicated by GEORGE BUCHANAN, M.D., F.R.S. Received March 2, 1892. The paralysis following diphtheria in man is so closely associated with the acute disease that it is more correctly considered as a symptom and not a sequela. Its mode of production in man has not been demonstrated. ; A chemical examination of the blood and spleen of eight patients who had died of diphtheria revealed the presence of two classes of substances not normally present in the tissues of the body, viz. (1) of (1892. ] On the Causation of Diphtheritic Paralysis. 79 two albumoses or digested proteids, proto- and deutero-albumose, giving the same chemical reactions as the albumoses of peptic diges- tion, and (2) of an organic acid, which is soluble in absolute alcohol and in water, to a less extent soluble in amyl! alcohol, and insoluble in ether, chloroform, or benzene. There is no base or alkaloid present. Owing to the small quantities in which this acid was obtained, a more detailed chemical examination was not possible. Physiological Action of the Albumoses—When injected into the circulation of a healthy rabbit these albumoses produce fever. If a single dose only be given, the fever subsides, and the animal remains apparently well for months. A single dose, however, may kill in a few hours. arn Repeated doses of the albumoses, besides producing fever, cause a paralysis which may come on in two days, but more often is evident in six or’seven days, and may be delayed for twenty days if the dose is small. The total doses given were between 0°083 gram and 0°157 gram per kilo. of body-weight in rabbits weighing between 1000 and 2000 grams. The paralysis is not complete, but is a paresis, and is not accom- panied by any special wasting of the paralysed parts. The paralysis is progressive, and, if the dose be large enough (over 0°] gram per kilo. of body weight), the animal dies in syncope with either slow or quickened respiration. The animals that do not die, but show paralysis, may have syncopal attacks, with an affection of the respiration; but they recover from these. | Five animals were used for experiment, and they all showed the same symptoms, including a loss of body weight, which is proportional to the dose of the albumoses. A post-mortem examination of these animals showed that the blood was slow in coagulating with the largest doses. Bacteria were absent from the blood and tissues, and in only one case was any cedema (of the abdominal wall) found. After staining with osmic acid and counterstaining with borax- carmine, the nerves were found extensively degenerated, while the spinal cord, spinal ganglia, and brain were normal. The degeneration of the nerves is what has been described by Gombault* in his experiments on lead poisoning as ‘‘un névrite- segmentaire périaxile,” or a segmental degeneration. This degeneration affects a segment of the nerve; the fibres at that part lose their white substance of Schwann, and the axis cylinders become attenuated, and,in many cases, ruptured. If the axis cylinder * < Archives de Physiologie,’ 1880-81, p. 11. 80 On the Causution of Diphtheritic Paralysis. [Mar. 17, becomes ruptured, the nerve fibre below the point undergoes the Wallerian degeneration. The early stage of the segmental degenera- tion is the breaking up of the white substance of Schwann. There may be more than one degenerated segment in the nerve which may then undergo completely the Wallerian degeneration. Above the degenerated segment the nerve is normal, the change being simply peripheral and not central in origin. All nerves in the body may be affected by this degeneration: the motor nerves, the sensory, and the visceral (sympathetic). An example may be quoted to show the extent of the nerve change. A rabbit, which received two doses, equal to 0:1 gram per kilo. of body weight, showed definite palsy on the twentieth day, and was killed on the twenty-fourth. Segmental degeneration was found in the following nerves :— I. Moror. Of leg. Nerve to sartorius. » vastus. 5 semimembranosus. » semitendinosus. > buceps: » gastrocnemius. Of arm. Nerve to pectorales. 5) treceps. 2 mbICepS. » Hexor of forearm. Of diaphragm. Phrenic. Of laryngeal muscles. Left recurrent laryngeal. Of psoas. Of eye muscles. Branches of third cranial nerve. IJ. Sensory NeERves. Long saphenous nerve. Cutaneous thoracic nerve. TI. Viscerat. The lower part of right cervical sympathetic. The nerve change is, therefore, widely spread over the body. Physiological Action of Organic Acid.—This is much less toxic than the albumoses, and I have not succeeded in producing paralysis with it. It, however, produces a moderate degree of nerve degeneration when injected into the circulation. 1892.] Presents. 81 The nerve degeneration is associated with a fatty degeneration of the muscles, which is proportional to the degree of degeneration. The heart, in all cases, shows advanced fatty degeneration. Diphtheritic Membrane—The membrane in diphtheria consists chemically of fibrin, hetero-albumose, proto-, and deutero-albumose, 7.€.,1t is in a state of digestion. From it was obtained an extract which was 3—5 times as toxic as the albumoses removed from the body, producing the same symptoms (fever, paralysis) and the same nerve degeneration. This poison is probably the same as that isolated by Roux and Yersin, and is presumably of a ferment nature, the albumoses and organic acid found in the bodies of the patients being the result of the action of the ferment on the proteids of the tissues. Diphtheria would, therefore, be, from this point of view, a disease in which the Bacillus diphtherie growing in the membrane excretes a ferment which, being absorbed, digests the proteids of the body, with the formation of albumoses and an organic acid, the action of the former of which is-to produce fever and paralysis dependent on nerve degeneration. Presents, March 17, 1892. Transactions. Hamburg :—Naturhistorisches Museum. Mittheilungen. Jahrg. 1890-91. 8vo. Hamburg 1891. The Museum. Jamaica :—Institute of Jamaica. Journal. Vol. I. No. 2. 8vo. Kingston 1892. The Institute. London :—Aristotelian Society. Proceedings. Vol. I. No. l. Part 1. 8vo. London 1892. The Society. British Museum. Catalogue of Arabic Glass Weights. 8vo. London 1891; Catalogue of the Cuneiform Tablets in the Kou- yunjik Collection. 8vo. London 1891; Subject Index of the Modern Works added to the Library in the Years 1885-90. 8vo. London 1891. The Trustees. Institute of Brewing. Transactions. Vol. V. No. 4. 8vo. London 1891. The Institute. Victoria Institute. Journal of the Transactions. Vol. XXV. No. 97. 8vo. London 1892. The Institute. Philadelphia :—American Museum of Natural History. Bulletin. Vol. TV. No.1. 8vo. Philadelphia 1892. © The Museum. Stockholm :—Kongl. Vetenskaps-Akademie. Ofversigt. Arg. 48. No. 10. 8vo. Stockholm 1891. The Academy. Warwick :—Warwickshire Natural History and Archeological Society, Report, 1892. 8vo. Warwick. The Society. VOL. LI, G 82 Presents. Observations and Reports. Adelaide :—Observatory. Meteorological Observations. 1889. Folio. Adelaide 1891. The Observatory. Budapest :—Ko6nigl. Ungar. Central-Anstalt fiir Meteorologie und Erdmagnetismus. Jahrbiicher. Bd. XIX. Jahrg. 1889. 4to. Budapest 1891. The Institute. Helsingfors :—Institut Météorologique Central. Observations. Vol. IX. livr.1. 4to. Helsingfors 1891. The Institute. London :—Meteorological Office. Weekly Weather Report. Vol. IX. Nos. 6-8. 4to. London 1891; Summary of the Observa- tions made at the Stations included in the Daily and Weekly Weather Reports. July to September, 1891. 4to. London 1892. The Office. Luxemburg :—Institut Royal Grand-Ducal. Publications. Tome XXI. 8vo. Luxembourg 1891; Observations Météorologiques faites A Luxembourg de 1884—1888. .'Tome V. 8vo. Luaem- bowrg 1890. The Institute. Lyme Regis:—Rousdon Observatory. Meteorological Observa- tions. 1890. 4to. London 1891. The Observatory. — Madras :—Government Observatory. Meridian Circle Observations. 1871—1873. Ato. Madras 1892. The Observatory. Wellington, N.Z. :—Registrar-General’s Office. Statistics of the Colony for 1890.. Folio. Wellington 1891; Report of the Statistics of New Zealand. 1890. 8vo. Wellington 1892. | , The Office. Fourteen Carte de Visite Photographs of Fellows of the Royal Society. Messrs. Maull and Fox. Temperature of the Brain in relation to Psychical Activity. 83 March 24, 1892. Mr. JOHN EVANS, D.C.L., LL.D., Treasurer and Vice-President, in the Chair. The Right Hon. Spencer Compton Cavendish, Duke of Devonshire, was admitted into the Society. A List of the Presents received was laid on the table, and thanks ordered for them. The Croonian Lecture was delivered as follows :— CROoONIAN LECTURE.—‘%“ The Temperature of the Brain, especi- ally in relation to Psychical Activity.” By ANGELO Mosso, Professor of Physiology in the University of Turi Re- ceived March 24, 1892, (Abstract. ) In his investigations on the temperature of the brain the author has employed, in preference to the thermo-electric pile, exceedingly sen- sitive mercurial thermometers, constructed specially for the purpose. Since each thermometer contains only 4 grams of mercury, the instruments respond very rapidly to changes of temperature, and a change of not more than 0'002° C. can easily be measured by means of them. The author has studied the temperature of the brain, com- paring it with that of arterial blood, of the muscles, of the rectum, and of the uterus; his observations were made on animals under the influence of morphia or various anesthetics, and also on man. The curves of the observations made show that in profound sleep a noise, or other sensory stimulus, is sufficient to produce a slight development of heat in the brain, without the animal necessarily awakening. ; In profound sleep the temperature of the brain may fall below that of the blood in the arteries. This is due to the very great radiation of heat which takes place from the surface of the head. The brain when subjected to the action of the ordinary interrupted current rises in temperature. The rise is observed earlier in the brain than in the blood, and the increase is greater in the brain than in the general blood-current or in the rectum. During an epileptic seizure brought on by electrical stimulation of the cerebral cortex, G 2 84 Temperature of Brawn and Psychical Activity. [Mar. 24, the author observed within twelve minutes a rise of 1° C. in the temperature of the brain. Asarule the temperature of the brain is lower than that of the rectum; but intense psychical processes, or the action of exciting chemical substances, may cause so much heat to be set free in the brain that its temperature may remain for some time 0:2° or 0°3° C. above that of the rectum. When a dog is placed under the influence of curare, the tem- perature of the brain remains fairly high, while that of the muscles and that of the blood falls. The difference of temperature thus brought about is great and constant. In one instance, the temperature of the brain was 16° C. above that of the arterial blood in the aorta. Such observations warn us not to regard the muscles as forming, par excellence, the thermogenic tissue of the body. In order to show how active are the chemical processes in the brain, it is sufficient to keep the animal in a medium whose temperature is the same as that of the blood. When the effects of radiation through the skull are thus obviated, the temperature of the brain is always higher than that of the rectum, the difference amounting to 0°5° or 06° C. Observations made while an animal is awake tend to show that the development of heat due to cerebral metabolism may be very con- siderable, even in the absence of all intense psychical activity. The mere maintenance of consciousness belonging to the wakeful state involves very considerable chemical action. The variations of temperature, however, observed in the brain, as the result of attention, or of pain or other sensations, are exceedingly small. The greatest. rise of temperature observed to follow, in the dog, upon great psychical activity was not more than 0:01°C. When an animal is conscious, no change of consciousness, no psychical activity, however brought about experimentally, produces more than a slight effect on the temperature of the brain. The author shows an experiment by which it is seen that, as part of the effect of opium, the brain is the first organ to fall in temperature, and that it may continue to fall for the space of eighteen minutes, while the blood and the vagina are still rising in temperature. The author discusses the elective action of narcotics and anes- thetics. He shows that these drugs suspend the chemical functions of the nerve-cells. Ina dog rendered completely insensible by an anesthetic, one no longer obtains a rise of temperature upon stimu- lating the cerebral cortex with an electric current. These results cannot be explained as merely due to the changes in the circulation of the blood. The physical basis of psychical processes is probably of — the nature of chemical action. In another experiment, in an animal rendered insensible with 1892.] | Presents. 83 chloral, the curves of temperature show that when the muscles of a limb are made to contract, the temperature of the muscles rises, but falls rapidly as soon as the stimulation ceases, soon returning to the normal. This is not the case, however, with the brain excited by an electric current. Here the stimulus gives rise to a more lasting pro- duction of heat; the temperature may continue to increase for several minutes after the cessation of the stimulation, indeed often for half an hour. ‘This may possibly explain why, upon an electric stimulation of the cerebral cortex, the epileptiform convulsions are not immediately developed, but only appear after the lapse of a latent period of several minutes. This experiment may be made to show the elective action exercised upon the brain by stimulant remedies. The injection of 10 centigrams of cocaine hydrochlorate produces a rise of temperature in the brain of 0°36° C., without any change in the temperature of the muscles or of the rectum being ok:served. In a curarised dog, the intervention of the muscles being thereby excluded, the action of the cocaine may produce a rise of as much as 4° C. in the temperature of the brain, the author having observed a rise from 37° to 41° C. This shows that in arranging the calorific topography of the organism a high place must be assigned to the brain. The author concludes by expressing the hope that the comparative study, by the direct thermometric method, of the temperature of the various organs of the body will enable us to push forward our knowledge of the phenomena of life. Presents, March 24, 1892. Transactions. Belgrade :—Royal Servian Academy. Spomenik. Nos. 10, 12, 13. Ato. Beograd 1891-92; Glas. No. 30. 8vo. Beograd 1891; Jovan Bak: Jedan Biographski Zapis. 8vo. Beograd 1891. The Academy. Berlin :—Gesellschaft fir Erdkunde. Zeitschrift. Bd. XXVI. No. 6. 8vo. Berlin 1891. The Society. Bucharest :—Societate de Sciinte Fizice. Buletin. Anl. No, 2. 8vo. Bucuresci 1892. The Society. Buenos Ayres:—Museo Nacional. Anales. Entrega 18.. Ato. Buenos Atres 1891. The Museum. Lausanne :—Société Vaudoise des Sciences Naturelles. Bulletin. Vol. XXVII. No. 105. 8vo. Lausanne 1892. The Society. Leipsic :—Ko6nigl. Sachs. Gesellschaft der Wissenschaften. Be- richte (Math.-Phys. Classe). 1891. Heft 4. 8vo. Leipzig 86 Presents. Transactions (continued). 1892; Berichte (Philol.-Histor. Classe). 1891. Heft 2-3. 8vo. Leipzig 1892. ) The Society. London :—Royal Medical and Chirurgical Society. Medico-Chir- urgical Transactions. Vol. LUXXIV. 8vo. London 1891. The Society. Royal United Service Institution. Journal. Vol. XXXVI. No. 169. 8vo. London 1892. ~ The Institution. Paris :—Faculté des Sciences. Théses présentées pendant l’Année — 1891. 8vo and 4to. Paris 1890-91. The Faculty. Prague :—Konigl. Bohmische Gesellschaft der Wissenschaften. Abhandlungen (Math.-Naturw. Classe). Folge VII. Bd. 4. Ato. Prag 1892; Abhandlungen (Philos.-Histor.-Philol. Classe). Folge VII. Bd. 4. 4to. Prag 1892; Sitzungsberichte (Math.-Naturw. Classe). Jahrg. 1891. 8vo. Prag 1891; Sitzungsberichte (Philos.-Histor.-Philol. Classe). Jahrg. 1891. 8vo. Prag 1891; Jahresbericht. 1891. 8vo. Prag 1892; Spisuv, &e. Cislo VI. 8vo. v Praze 1891. The Society. Washington :—U.S. National Museum. Proceedings. Vol. XIV. Nos. 880—881. 8vo. Washington 1891-92; Bulletin. Nos. 41-42. 8vo. Washington 1891. The Museum. Journals. Astronomy and Astro-Physics. ‘February, 1892. 8yvo. Northfield, Minn. The Editor. Horological Journal. Vol. XXXIV. No. 403. 8vo. London 1892. The British Horological Institute. Revista do Observatorio. Anno VI. No. 12. S8vo. Rio de Janeiro 1891. The Observatory, Rio de Janeiro. Revue Médico-Pharmaceutique. Année V. No. 2. 4to. Con- stantinople 1892. The Editor. Timehri. Vol. V. Part 2. New Series. S8vo. Demerara 1891. Royal Agricultural and Commercial Society of British Guiana. Bonneau (H.) and E. Desroziers. Etude sur la Traction Electrique des Trains de Chemin de Fer. 8vo. Paris 1892. The Authors. Burdett (H.C.) SBurdett’s Official Intelligence for 1892. Oblong. London 1892. Mr. Burdett. Cuervo (H.) Estudio sobre el Sistema Evolucionista. 8vo. Bogota 1891. The Author. Apparatus for ascertaining the Sensitiveness of Safety-lamps. 87 Dieterici (Fr.) Alfarabi’s Philosophische Abhandlungen. 8vo. Leiden 1892. The Author. Fayrer (Sir J.), F.R.S. On Serpent-worship and on the Venomous Snakes of India. 8vo. London. The Author. Hehir (P.) Microscopical Observations on the Hematozodn of Malaria. 4to. Madras [1891]. The Author. Riced (A.) Terremoti Sollevamento ed Eruzione Sottomarina a Pantelleria. 4to. Homa 1892. The Author. Wolf (R.)