1403 LOTHAR MEYER MEMORIAL LECTURE. By P. PHIILLIPS BEDSOS, M.A., D.Sc., F.I.C. WE meat this evening a t the invitation of the Council of this Society to contemplate the life and work of a man who, little more than year ago, passed away after a sudden and painless attack, and thus would we pay our homage to the memory of one who has in so great H variety of ways contributcd to the advancement of the science, the fostering and promotion of which me a11 have at heart. The chronicles of the liFe of a man of science are usually of 5t simple character, presenting to all, save those who either enjoyed his personal friendship or have a special interest in the scieutific work of the individual, little of apparent note. But for us, as Fellows of R Society which has lost one of its most d i s h p i s h e d members, and to marly of whom he stood as friend and fellow student, and to the majority as guide and instructor in the fundamental theories and facts of our science, no one item of the chronicle of the life of Lothar Meyer can fail to be of interest.Julius Lothar Meyer was born on the 19th of August, 1830, at Varel ou the Jade, in the Grand Duchy of Oldenburg. His father, Dr. Friedrich August Meyer, was in practice as a medical man in that town ; and his mother, Frau Anna Sophie Wilhelmine, ne’e Biermann, also a native of this same place, was the daughter of a medical man who, during his lifetime, was highly respected and esteemed, and whose memory was cherished in Varel for many years after his death. Lothar Meyer’s mother was an only child, the constant companion of her father, and imbibed from him a love for the pro- fession, which enabled her not only t o enter fully and sympathetically into the labours of her husband, but often-despite her feeble health -to lend assistance in surgical operations.These facts, together with the respected position which their father held, readily explain how Lothar and his brother, Professor Oskar Einil Meyer, should, at the outset of their careers, have decided to follow medicine as their life’s profession. But, fortunately for science, this decision was not carried to its ultimate isaue ; by one brother, medicine was forsaken for chemistry, and by the other for the sister science of physics. Lothar Neyer’s early education was received at a small private school, and from thence he passed t o the recently founded “Burger- schule,” in Varel, at which he remained until his fourteenth year, receiving, meanwhile, private izlstruction in Latin, Greek, and the niodern languages.His rapid growth and consequent delicate health1403 LOTHAR MEYER MEMORIAL LECTURE. By P. PHIILLIPS BEDSOS, M.A., D.Sc., F.I.C. WE meat this evening a t the invitation of the Council of this Society to contemplate the life and work of a man who, little more than year ago, passed away after a sudden and painless attack, and thus would we pay our homage to the memory of one who has in so great H variety of ways contributcd to the advancement of the science, the fostering and promotion of which me a11 have at heart. The chronicles of the liFe of a man of science are usually of 5t simple character, presenting to all, save those who either enjoyed his personal friendship or have a special interest in the scieutific work of the individual, little of apparent note.But for us, as Fellows of R Society which has lost one of its most d i s h p i s h e d members, and to marly of whom he stood as friend and fellow student, and to the majority as guide and instructor in the fundamental theories and facts of our science, no one item of the chronicle of the life of Lothar Meyer can fail to be of interest. Julius Lothar Meyer was born on the 19th of August, 1830, at Varel ou the Jade, in the Grand Duchy of Oldenburg. His father, Dr. Friedrich August Meyer, was in practice as a medical man in that town ; and his mother, Frau Anna Sophie Wilhelmine, ne’e Biermann, also a native of this same place, was the daughter of a medical man who, during his lifetime, was highly respected and esteemed, and whose memory was cherished in Varel for many years after his death.Lothar Meyer’s mother was an only child, the constant companion of her father, and imbibed from him a love for the pro- fession, which enabled her not only t o enter fully and sympathetically into the labours of her husband, but often-despite her feeble health -to lend assistance in surgical operations. These facts, together with the respected position which their father held, readily explain how Lothar and his brother, Professor Oskar Einil Meyer, should, at the outset of their careers, have decided to follow medicine as their life’s profession.But, fortunately for science, this decision was not carried to its ultimate isaue ; by one brother, medicine was forsaken for chemistry, and by the other for the sister science of physics. Lothar Neyer’s early education was received at a small private school, and from thence he passed t o the recently founded “Burger- schule,” in Varel, at which he remained until his fourteenth year, receiving, meanwhile, private izlstruction in Latin, Greek, and the niodern languages. His rapid growth and consequent delicate health1404 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. necessitated the discontinuance of school work for a time, and his father placed him as a pupil under the chief gardener at the surnrnei- palace of the Grand Duke of Oldenburg, at Rastede.The healthy occupation and the new surroundings soon served to restore the bodily health of the young Lothar, who also gained that lore of nature and taste for gardening which remained a source of enjoyment and recreation to the endof his life. After a year’s sojourn at Rastede, Meyer was sufficiently recovered to be able to resume his studies and to enter the Gymnasium at Oldenburg, at which school he remained until Easter of 1851, when he obtained the “ Zeugnisa der Reife.” I n the summer session of 1851, Lothar Meyer commenced the study of medicine in the University of Zurich, where E’rey was Professor of Anatomy and Ludwig directed the study of Physiology. From Ziirich, in 1833, lie went to Wiirzburg, where the lectures of Virchow on Pathology appear to have been especially attractive to the then student of medicine, who threw his energies completely into the work, industriously visiting the infirmary and actively discharging his duties as a student in the practice of medicine.On the 25th of February, 1854, after a year’s residence in Wurzburg, Lothar Meyer graduated as Doctor of Medicine. Notwithstanding the zeal displayed in the prosecution of his studies, ere the course was completed, doubts arose in the mind of Meger as to the wisdom of his decision to make the practicc of medicine his voca- tion. The attraction expeiienced for the more scientific side of the study gradually asserted itself, and it was only his modest estimate of hia own talents which prevented him arriving at an independent decision.In his doubts as to whether he mere able to advance Roience by his own investigations, Meyer turned to his former teacher, Professor Ludwig, asking for advice on this question. To Meyer’s applicatiou the reply came with no uncertain sound, Ludwig advising Lothar Meyer to put aside all doubts, and to embrace the calling which could alone be congenial t o him. The decision arrived at in the summer 9f 1853, to devote himself to the study of physiological chemistry, was the immediate consequence of the advice of the teacher ; and in the following spring, when his medical studies had been completed and the examination for the Doctor’s Degree had been passed, Lothar SIeyor turned his steps to Heidelberg to study chemistry under Bunsen, and to complete the working out of his dissertation.This letter occupied Meyer’s energies until the autumn of 1856, by which time the investigation on the ‘‘ Gases of the Blood ” was published and forwarded to the Medical Faculty of Wurzburg, by whom it was accepted as inaugural dissertation for the Docto~s’s Degree.BEDSON : LGTHAR MEPER MEMORIAL LECTURE. 1405 The years spent at Heidelberg were times of great moment, and their influence is to be distinctly tyaced in the subsequent work of his life. Many are there in the foremost ranks of the Fellows of this Society who, like Lothap Meger, cherish the fondest recollection of the genial influence of their teacher, Robert Bunsen, whose reputtt- tion for so many years attracted students of chemistry from all parts of the world to Heidelbcrg.Wherein the attraction lay, those of us who have not been so privileged can only guess ; assuredly it was not to be found in a laboratory equipped with all our modern appliances, which do so much to ease the work of a student and so little to develop his resourcefulness ; but rat,her in the results, which cast a halo round the meagre tools with which so many of the all-important discoveries in our science have been made, and make these the desperation of our modern refinements. A description of Gmelin’s laboratory in the cloisters of the old monastery at Heidelberg, in which Meyer worked f o r a year side by side with one of our past Presidents, Sir Henry Roscoe, who has so successfully transplanted much of the Bunsen enthusiasm and methods to this country with inestimable benefit, might serve to rouse feelings of doubt and astonish- ment in the minds of the present day student at the possibility of doing eacient work, where combnstions were made with charcoal as fuel, and other heating operations performed with Berzelius’s spirit lamp ; it may, perhaps, serve to heighten their appreciation of the skill and ability of those who, by the use of such appliances, could obtain resalts of which we have so excellent an example in Lothar Meyer‘s classical investigation of the “ Gases of the Blood.” During Meyer’s Heidelberg “ Studienzeit ” the new laboratory mas opened, with gas and water laid on to all the benches, and the spirit lamp replaced by the Bunsen burner.What these altered conditions of work meant to Meyer and his fellow students i t is difficult for many of us to fully realise.The recollection of the Heidelberg days was ever a source of pleasure and delight to Meyer, who frequently re- ferred to his “ lioch zitrehrter Lehrer,” to whom he dedicated what must be regarded as his magnum opus-Die Nodernew Theorien der Chemie ; nor did Meyer, in recalling the past, forget to remind his hearers of‘ his fellow students, with many of whom he formed life-long friendships. The names of these fellow students include many whose names are honourably associated with the growth and extension of the science of Chemistry during the past 40 years, as the following list attests :- Roscoe, Russell, Atkinson, Baeyer, Beilstein, Barth, Landolt, Lieben, Meidinger, Pebal, Qnincke, and Sehischkow.Nor should it be for- gotten that at this time there worked a t Heidelberg, in the capacity of Privat-Docent, August KekulB, to whom we owe the recognition of the tetravalency of carbon and the theoretical elucidation of the1406 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. constitution of benzene and of the aromatic compounds, theories which have so materially contributed to the advancement of organic chemistry during the past 30 years. During the years spent at Heidelberg, the separation from medi- cine gradually became more pronounced, and the final step drew nearer. Whilst at the University of Heidelberg, Meyer attended Kirchhoff’s lectures, and thus gained an introduction and insight into the mathematical treatment of scientific questions. The decisive blow was struck, the election made, when Lothar Meyer, in company with his friend, Pebal, and in answer t 9 his brother’s entreaty, turned his steps to Konigsberg-there t 3 devote himself to the study of mat hematical physics under the direction of Professor Franz Neu- mann.From that moment, t o quote the words of Professor Oskar Emil Meyer, (‘war die Richtung entschisdert, in d_pr Lothar’s Forscher - geist in Zukunft thatig seiiz sollte, er war fiir die physikalische Chemie gewonnen.” During the year and a half spent at Konigsberg Meyer prosecuted an investigation on the action of carbon monoxide on the blood, tvhicli, in the spring of 1858, was presented to the Fasulty of Philo- sophy in Breslau as dissertation, with the title De Sanguine Onydo Carbonic0 infecto, for which he obtained in July of the same year the degree of Doctor of Philosophy.In the February of the following year, Lothar Meyer established himself as Privat-Docent in Physics and Chemistry in the University of Breslsu, presenting for this pur- pose a brochure on the ‘‘ Chemical Teachings of Berthollet and of Berzelius,” and selecting for his inaugural l e h r e the subject of the ‘‘ so-called Volametric Methods of Chemistry.” A t the outset, Meyer undertook the direction of the chemical laboratory attached to the Physiological Institution, and during his residence in Breslau, delivered several courses of lectures on various branches of chemiHtry applied to physiology, and conducted tutorial classes in both Inorganic and Organic Chemistry. I n Professor Seubert’s account of the life and work of his highly esteemed and honoured teacher, to which, as also t o the writer, I would wish to express my indebkeduess for much of the information embodied in this lecture, there is reprodnced a letter from the Curator of the university, Ober-Prasident von Schleinitz, which shows how completely and unselfishly Meyer threw himself into his new sphere of work ; not contenting himself with unstinted devotion of time and energy, he unsparingly and liberally dispensed much of his worldly goods for the benefit of the Institute.This is all the more worthy of note, seeing that Lothar Meyer himselE WAS not by any means a rich man, and the legacy he inherited from his father, who died a year before Meyer began his university stmudies, had alreadyBEDSON : LOTHAR METER MEMORIAL LECTURE.1407 been materially diminished to supply the “ needf id ” during the L L Lelw- und Wanderjah~en.” In the winter of 1859 one of the Heidelberg group of friends, Beilstein, whose name is a household word amongst chemists, came to Breslau in the capacity of Assistant to Professor Lowig, and in 1864 Lothar Meyer was joined by his brother, Oskar Emil Meyer, who became Professor Extraordinary in Mathematics and Mathematical Physics, to succeed in 1867 to the position of Professor, which he still occupies. It was dnring the residence at Breslau that the Modemen Theorien der Chemie was written, as Meyer himself tells us in his preface to the fourth edition, “ with the desire and hope that its publication might contribute t o the removal of doubts and uncertainties, so frequently expressed at that time, as to the character of the views and theories then contending for supremacy in chemistry.” “ And at the same time to give to others interested in the science an account such as would lead to an understanding of the change through which the system of chemistry had just passed.” The book was written i n 1862, but not published until 1864; it attracted considerable attention at the time, and has materially con- tributed to spread the fame of Lothar Xeyer in all parts of the scientific world. Tw-o years after the publication of this work, Meyer received an inritation to become a teacher in the School of Forestry at Neustadt- Eberswalde, with the understanding that, should circumstances allow, he should receive a Professorship. The invitation was accepted, and in October, 1866, after seven years’ activity in Breslau, Lothar Meyer began the duties of his new position.The post can scarcely be regarded as an ideal one for a specialist, and the descrip- tion given in the invitation cannot he considered as altogether encouraging to one of Meyer’s tendencies, as indicated by his pub- lished works. He was here required to teach the whole of inorganic natural science, more especially mineralogy, chemistry, and physics, nud also to undertake the direction of the study of botany. Before settling at Eberswalde, Meyer married on the 16th August, 1866, Johanna Volkmann, a relative of the famous surgeon, Volk- rnann. Frau Meyer, to whom I am indebted for directing my atten- tion to several important facts in her husband‘s career, still survives, together with their four children. The two years spent at Eberswalde do not appear to have afforded many opportanitics for the development of his ability as an investi- gator, and Meyer cannot long have hesitated as to the manner of the reply he should make to the invitation received in February, 1868, to become the successor of Weltzein at the Carlsruhe Polytechnicum1408 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. the duties of which Professorship he took over in the autumn of illis same year. Shortly after the settlement at Carlsruhe came an invitation to the Professorship at Konigsberg in Prussia, which was declined chiefly on the grounds of geographical position and donbts as to the suit- ability of the clirnate-a decision the more readily made as the Government undertook, in accordance with the wishes expressed, tro provide a residence for the Professor nearer to the Polytechnicum than the one he occupied.The necessity for the change was shown when, in the autumn of 1874, Meyer failed in health to such an extent as to necessitate him relinquishing his duties for the entire winter session, 1874-18 75. The &‘ even teriour ” of the days at Carlsruhe was also interrupted by the outbreak of hostilities between France and Germany, and the Polytechnicurn was transformed into a hospital for the reception of the wounded. Reviving his medical studies, the professor of chem- istry became the active and zealous surgeon.In recognition of these services, Meyer received, at the conclusion of the war, the medal for non-combatants and the ‘( Erinnerungs-Zeichen fur Hulfsthatigkeit im Kriege.” By these rewards for services rendered to his country in its hour of need Meyer, throughout his life, set more than special store. During the residence in Carlsruhe, which extended over some eight years, an attachment to the place had been gradually formed, and the worth of the man had made itself felt throughout the widest circles of its life. Still the call to fill the Chair of Chemistry in the Uni- versity of Tubingen, in succession to Pittig, who had been promoted to Strasburg, was one which could not be resisted, offering as it did a, freer and more congenial field of labour than that afforded by the necessarily more restricted teaching of the Polytechnicurn.Thus, in the spring of 1876, Lothar Meyer became university professor, and for him then began the most productive period of his life. Many investigations commenced in the earlier days and discontinued by reason of unfavourable conditions, were again resumed and brought to a final issue. The name of the Professor served to attract students to the laboratories at Tubingen, and amongEt these vcere to be found representatives of many lands who, in Lothar Meyer, found not only the rimn of learning, the conscientious, painstaking and inspiring teacher, and all that his fame would entitle them to expect, but also one desirous and ready to be their friend. His pupil, and for many years assistant and colleague, Professor Seubert, has given in the Memoir recently published by the German Chemical Society of Berlin, a sketch of the daily life at Tubingen, which shows the high ideal Lothar Meyer had formed of the duties ofBEDSON : LOTHAR MEPER MEMORIAL LECTURE.1409 llis position, and with what marked siiccess that ideal was ivalised. From this portrayal we carry away with us the picture of a man elldowed with gifts and high intellectual powers which entitle his name to a foremost position amongst the names of those who have been contributors to the scientific development of chemistry during the past 40 years. To t.hese were added that modesty and simplicity of character, that love of truth and high smse of honour which secured the respect and appreciation of his colleagues, and inspired the goodwill of his fellow townsmen.The meeting of the British Association in Xenchester in 1887, memorable as i t was in many ways, was more than ordinarily so to chemists. The place oE meeting was John Dalton’s adopted city, the President, Sir Henry E. Roscoe, the founder of the School of Chem- istry there, and to whose zeal and devotion Mancliester is chiefly indebted for the erection of the pile of buildings in which the Asso- ciation was housed, and there-further to enhance the interest-were to be seen Meyer and Mendelkeff genially active i n promoting the work of Section B, under the presidency of one of Liebig’s pupils, Dr. Schunck, whose investigations have greatly added t o our stock of knowledge of alizarin, indigo, chlorophyll, and other vegetable colouring matters.I am reminded of one incident during the meeting which must have left an impression on the minds of all those present ; when, at the conclusion of Dr. Schunck’s address, there was a call f o r a speech from MendelGef, he declined to make an attempt to address the section in English, and simply rose in his place to bow his acknowledgments, an action followed by the rising of DIeyer from his seat next to Mendelkeff, and who, as if to prevent any misconcep- tion, prefaced his speech with the declaration, “ I am not MendelBeff,” a statement which may, perhaps, have disappointed some of his hearers, but the round of applause which greeted his further remark, ‘‘1 am Lothar Meyer,” proved that the feeling, if it existed at all, was more than counterbalanced by the anticipation of the pleasure of listening to the words of one whose name will ever in the annals of our science be justly associated with that of the great Russiaa chemist.The applause which greeted this opening having subsided, Meyer, speaking in faultless English, asked permission to address the section in German, and then proceeded, on behalf of Mendelheff and other foreign chemists present, t o express the pleasure they had derived from listening to the Presidentrial address. For ithe academic year of 1894-95 Meyer had beenelected to be the Rector of the University of Tiibingen, the exercise of the duties of which position had scarcely been relinquished ?hen, on the evening of the 11th oE April OE last year, whilst busily engaged in his garden -a form of recreation in arhich Meyer from the days oE hisresidence1410 BEDSON : LOTBAR MEYER MEXORIAL LECTURE.a t Rastede had continued to delight-he felt the symptoms of an approaching illness. Shortly after entering t’he house he became unconscious, and a t 11 o’clock, six hours from the time of the first attack, Lothar Meyer passed quietly away, surrounded by those endeared to him by the highest of all worldly relationships. And whiIst in the sudden death of Lothar Meyer we mourn the close of the life of a man in the full enjoyment of bodily vigour and of a ripened intellectual activity, whose lovable simplicity of character, whose honesty of purpose, whose breadth of sympathy had endeared him to a wide circle of life-long friends and colleagues, our sorrow is as great at the loss t o science of one whose unremit- ting labours in so many of its branches have enriched it with incal- culable gain.Lothar Meyer’s scientific publications embrace a remarkable variety of subjects and display intellectual attainmerits which find him alike a t home, wbether in the devising of experiments for lecture illustration, the designing of apparatus to supply some want experienced in the laboratory, or needed for the conduct of the in- vestigations of physical constants, or in the extension of chemistry by literary labours and theoretical speculations. As I have already mentioned, Meyer’s first experimental investign- tions belong to the domain of Pbysiological Chemistry, and of these the two most important are Lhose concerned Kith the investigation of the chemistry of the blood.The first paper ‘‘ On the Gases of the Blood,” was published in 1856, in the Zeitsch~ift f i i y Rationelle Medicin, and was undertaken with the object of elucidating the question oE the conditions under which the gases exist in the blood. To solve, in fact, the question, then an open one, as to whether or no the gases are simply absorbed by the blood in quantities subservient to Dalton and Henry’s law, that is, in amounts determined by altera- tions in pressure. The paper, an abstract of which, from the pen of Sir Henry Roscoe, appeared in the Philosophical 2Clagazine of 185i, contains a detailed description of the method and apparatus used, and the results of the analjses of the gases expelled by boiling measured yolumes of blood diluted with water free from air in a vacuous apparatus.The proportion of carbon dioxide existing in a stmate of combination was also determined by acidifying with a few crystals of tartaric acid the blood from which the gases had been pre- viously expelled. The absorption by defibrinated blood of oxygen, carbon dioxide, and nitrogen was also submitted t o a carefully conducted quantita- tive investigation, and with the object of throwing further light upon this all-important subject, the behaviour of solutions of sodium car-BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 14 11 bonate towards caybon dioxide, and to this gas when mixed with others, for example, hydrogen, was examined. * Meyer, by this investigation, placed the chemistry of the gases of the blood iipon a firm experimental basis, proving that the views held at that time were not in accordance, but rather in direct opposi- tion to the facts brought to light by his experiments.Whereas, according to the older doctrines, the gases oxygen and nitrogen were simply absorbed by the blood, and chemical affinity was called in t o explain the manner in which the blood takes up and gives off carbon dioxide, the reverse mould appear to more nearly represent the facts. The greater portion of the oxygen taken up by the blood was proved by Meyer to be in amount independent of the pressure, and to exist in the blood in a state of loose combination with some one of its constituents. The assumption that in the tissues the carbonate of soda in the blood is converted into the bicarbonate, and that this compound gives up some of its carbon dioxide in the lungs, and thus again forms the carbonate, is shown to be essentially improbable.Such a series of chemical changes being entirely unnecessary, as the ab- sorption of the carbon dioxide and the liberation of this gas from the blood, find an all sufficient explanation in the laws regulating the absorption of gases by liquids. Marchand’s observation that no carbon dioxide is produced when oxygen is passed through defibrinated blood which has been pre- viously freed from its absorbed carbon dioxide, is confirmed by one of Meyer’s experiments, thus demonstrating the highly improbable nature of the hypothesis that carbon dioxide is produced by the im- mediate oxidising action of the oxygen in the blood.That the oxygen. existing i n the blood loosely combined with one of the blood constituents can easily pass into other and more stable modes of combination is demonstrated by an experiment made in the course of this investigation. It has already been mentioned that in determining the amount of the gases contained in the blood, the latter, after dilution with water free from air, was boiled and the gases so expelled, collected, measured, and analysed. The proportion of combined carbon dioxide was ascertained by adding crystals of tartaric acid to the diluted blood which had been previously boiled, and the gas liberated by the acid was collected and its volume measured. Meyer observed that if the acid be added before the gases are removed, the bulk of the oxygen is n o t driven off by boiling, a fact abundantly proved by experiments specially made to test the truth of this observation, and shown in the following tabulated results of the analyses of the gases obtained from two samples of blood taken in quick succession,1412 BEDSON : LOTHAR MEYER MEMORIAL LECTURE.(1) after treatment of the diluted blood a t once with tartaric acid, (2) aEter the ordinary method of extraction. Volume of Gases, a t 0” and 760 mm. presswe, obtained f r o m 100 Folztmes of Blood. Oxygen 3-79 18.42 Nitrogen ................ 2.94 4.55 Free carbon dioxide.. ...... - 5.28 Combined carbon dioxide.. . - 20.57 Total carbon dioxide ....... 27.10 26 2.5 I. 11. .................. This observation, demonstrating as it does that the loosely held oxygen readily enters into more stable combination with some con- stituent of the blood, shows clearly also that this oxidising action is not likely to occur in tbe blood vessels themselves, by reason of the alkalinity of the blood itself; but in the tissues, 8ome OC which are known to contain free acid, conditions favouralde to such changes may frequently occur.The conclusions drawn by Meyer from this iuvestigation form the teaching accepted a t the present dar, and are summarised at the close of the paper in the following words :- (( Das B l u t tragt in seiner eigenen Zusammensetzung den Begdator fiir die Aufnahme dieses wesentlichsten Lebensmittels, Ufiabhcingiy con2 wechselnden Drucke des. Atmosphare, zieht das Blu t i.n den Lungen den Sauelatof in ricl~tigen Terhaltnisse an, urn ihn den Organen z u zzcbringen.Nzcr eine Teriindemng des Blutes selbst bedingt eine erhebliche r e yander zcn q d el’ a uf g ei LO 11% i n ene n Quant i t at : jeJe BE u t en tz ie hung w ird daher zu einer XazLel.sto$enfziehung.” This first publication of Lothar Meyer’s, whether it be regarded from the stand-point of the skill displayed in devising means to solve tbe problem in question and in carrying out the experimental work with care and exactitude, o r from the attractire manner in which the results of the investigation are described and the careEul consideration of the conclusions which the results appeay to warrant, is justly entitled to a position amongst the classics of science.Our knowledge concerning the ‘,‘gases of the blood” received further extension by the resulta obtaged in the examination of the action of carbon monoxide on the blood. The results of this enquiry show that this gas is taken up by the blood under conditions similar to these regulating the behaviour of the latter towards oxygen : entering like oxygcn into a loose state of combination with some constituent of the blood, and capable of expelling and replacing volume for rolame the oxygen existing in combination with this substance.BEDSON : LOTHAR METER MEMORIAL LECTURE. 1413 Facts which offer a simple explanation of the poisonous action of carbon monoxide, Preliminary experiments made to discover the nature of the constituent of the blood which exercises this attrac- tion for oxygen and carbon monoxide were, owing to the interruption of the investigation, never brought to a successful issue.Some seveii years after the publication of this paper, Hoppe-Seyler suc- ceeded in isolating this constituent of the blood, which he named Hsmoglobin (Vi~chow’s Awhiu, 1864, 29, 233). Whilst at Breslau, Meyer published an account of a complete examination of the waters from the springs at Landeck, in Prussian Silesia, papers having more than local interest. They contain a description of a method €or estimating the carbch dioxide in natural waters dependent on the removal of the gases by means of a mercurial air-pump, instead of expelling them by boiling, and further attention is directed to the large proportion of nitrogen gas held i n solutiori by the waters from these springs.This last men- tioned fact is more than ordinarily suggestive at the present time in the light of the brilliant discoveries of Lord Rayleigh and Professor Ramsay. It \\-as during this period also that in conjunction with Heiden- hain an investigation was undertaken on the absorption of carbon dioxide by aqueous solutions of neutral sodium phosphate in order to determine the question at issue between Pagenstecher’s statement (1840), afterwards confirmed independently by Marchand (1843 j, and Liebig (1847), and the experimental results of Fernet (1658). Neyer and Heidenhain were successful in ref ding khe conclusions of the last, named investigator and placed the subject in a clear light, explaining the production of the sodium bicarbonate i n this instance as a mass action in terms of the teachings of Berthollet.These investigations belong to the early period of Meyer’s experi- mental work, which, until he became Professor at Carlsruhe, and finally passed to the still more congenial surroundings and duties of a University Professorship at Tubingen, were conducted under not altogether favourable circumstances. Whilst a t Carlsruhe and Tubingen, Mejer’s powers as a11 inves- ti&or are shown in a long series of publications, dealing with ques- tions pertaining to inorganic, organic, and general chemistry. Instead, however, of attempting to discuss the individual com- munications, it will undoubtedly be more worthy of and befitting the occasion upon which we are met if I direct attention to those investigations and speculations which have exercised no unimportant influence in chemistry during the pastl 30 years.Amongst these we have in the first place to consider the part Lothar Meyer took in the development of the great generalisation known VOL. L U X . 3 C1414 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. under the name of the ‘ I Periodic Law,’’ or tohe ‘‘ Natural System of the Chemical Elements.” One of his Jast literarv tasks was the editing for publication in t h e series of Classical Papera, published under the direction of Professor Ostwald, the papers of Dobereinei- and VOU Pettenkofer dealing with the relationships exhibited by the atomic weights of the elements and their physical and chemical properties. In an appendix to these papers, and in the explanatory notes is given an account of the extension which the conception of Dobereiner and von Pettenkofer received at the hands of Dumas, Gladstone, Cooke, Odling, and others. This subject,, some 11 years ago, provided the material for a lecture delivered by Meger at Plochingen (on January 25th, 1885), entitled “ Ueber die rheuere B~~twickelung dpr Atomlehre.” After rerie wing the earlier at tempts to discover relationships between the numerical values employed to represent the atomic weights of the elements, Meyer con- tinues :- “ When at the commencement of 1860 I undertook the preparation of a work which should place before chemists and other men of science the most important of the laws relating to the atoms and their compounds, I soon discovered that by the adoption of the new atomic weights a much greater uniformity existed in the relation- ships between the numbeiw representing the atomic weights, than had hitherto been observed.A t the same time there was shown a regular and continuous change in the vttlency of the elements from family to family, when the families are arranged in the order of the atomic weights of their members. I drew up at that time the following Table ‘I, and also directed attention to the fact that the first differences, with the exception in the case of beryllium the atomic weight of which was still uncertain, were approximately 16, the two following differences approximated to 46, and the last were very nearly double this, namely 87-90.” “ These last two sets of differences are repeated in the groups in the following table 11, in which the first members are wanting.“These groups were also arranged in the order of the atomic weights, with the exception of the last, which, because it consisted of ‘ members of uneven saturating capacities ’ (‘ Stittigicz7gs-capac~tat ’), appeared to me somewhat doubtfnl. At the same time, I did not ove~look the fact that these groups could he arranged t o make one complete table by placing them to the left of those in Table I, and thus placing cadmium before fin, and mercury before lead. The attempt to arrange all the elements in a single table was not succew- ful, inasmuch as certain erroneous atomic weights, namely, Mo = 92, V = 137, and Ta = 137.6, exhibited differences which led me to formulate the two groups contained in Table 111, which groupsTABLE I.Tetravalen t . I Tetravalent. j Tet,ravalent. --- r P Divalent, Difference . . . . . . . . Jifference . . . . , . , . Difference .. .. .. .. Difference . . , . . . . . Difference , . . . . . . . Tetravalent. I - c = 12.0 16.5 Si = 285 89.1 z 44.55 2 8x1 = 44.55 2 Sn = 117% 89'4 = 2 x 4 4 ' 7 Pb = 207.0 Trivalent, - - N = 14.M 16 -96 P = 31'0 44l.O Aa = 75'0 45.6 Sb = 120.6 84'4 = 2 x 43 a 7 Bi = 208.0 Divalen t. - - 0 = 16.00 16 Q7 S = 32.07 46 -7 89 = 70.8 49 '5 Te = 128-3 - - ~~~ TABLE 11. Monovalent . - - F = 19.0 C1 = 35.46 16 '46 G *51 Br = 79.97 46 *8 I = 126.8 - - Monovalent. Li = 7-03 16 -02 Na = 23'05 16 *08 K = 39-13 46 *3 m = 85.4 47 -6 CS = 133.0 71 = 2 x 35.5 (T1 = 204 3) Divalent.W (Be = 9*3?) W (14-7) Mg = 24.0 Ca = U . 0 16.0 5 47-6 5 Sr = 87'6 cn 0 Difference . . . . . . . , Difference . . . . . . . . = 55.1 Ru = 104.3 9L.8 = 2 X M -4 Pt = 197.1 ~~ ~ I Ni = 58.7 45 *6 R11 = 104 0 3 92.8 = 2 x 46.4 Ir = 197.1 Zn = 65.0 46 *9 Cd = 111.9 88.3 = 2 x 44.2 Hg = 200'2 44 '4 g Ag = 107.94 88.13 = 2 x 44.4 cI AU = 196.7 t+ c.r I I I I I cI11416 BEDSON : LOTHAR METER lllEMORIhL LECTURE. Tetravalent. could not in any way consistently be brought into arrangement with the other elementary bodies.” TABLE 111. Hexavalent. --- Ti = 48.0 42 ’0 Zr = 90.0 47 *6 Ta = 13’1.6 Difference ........ Difference ........ MO = 92 42 Vd = 137 47 w = 184 I- --- Such then in brief is Lothar Meyer’s own account of the inception of the classification of the elements, which finds a place in the first edition of the Modernen Theorien. The development of this subject in Meyer’s mind is shown in the sketch of a system of the elements, which, in manuscript form, Lothar Meycr handed, in July, 1868, to his successor in Ebers walde, Dr.Adolf Remelt5 (“ Ostwald’s Classiker der exakten Wissenschaften, No. 68, Ksrl Seubert. Zur Geschichte des Periodischen Systems,” Beit. nnorg. Chem., 9, 334). This table, which is reproduced below (vide Table IV), bears undoubted evidence of having been prepared for a possible new edition of the Modernen Theorien. The mark 9 91, which corre- sponds to the section in the first edition of the Modern Theories dealing with this subject, and the series of references given a t the foot of the table both justify this conclusion.The table contains two elements, namely, chromium and alumi- nium, in addition to those contained in the three tables o€ groups, and in some particulars certain elements have been rearranged ; thus iron displaces nickel, the latter being placed by itself between cobalt and copper, whilst chromium occupies a similarly isolated position and that of aluminium remains doubtful. Meyer himself appears t o have entirely overlooked the existence of this sketch until i t was shown to him by Dr. A. Remelt5 in 1893, on the occasion of his lecture, delivered to the Chemical Society at Berlin. The redetermination of the atomic weights of niobium and tantalum by Maxignac in 1865, and of vanadium by Roscoe in 1867, opened the way for further progress.In a comparatively short paper, dated from Carlsruhe, December, 1869, and contributed to Liebig’s A n d e n (Annalew, VII, Supplement- band 1870, 5, 354-364), Lothar Meyer showed his appreciation of the advantages the new atomic weights offered, and how with these new values some 56 elements including all those elements, saveTABLE TV. 2. 6. 4. --- A1 = 27.3 Go = 58'7 47 -3 Pd = 106.0 93 = 2 x 46.5 0 s = 199.0 7. S. 9. 10. 11. 12. 13. 14. 15. Li = 7.03 16 *02 N& = 83-05 16 '0s I< = 30'13 46 '3 Rb =- 85 *4 47 -6 CS = 133'0 71 = 2 x 35-5 ? TI = 204? Be = 9 . 3 14 '7 I\Ig = 2 4 - 0 16 *o Ca = 40-0 47 -6 Sr = 87'6 49 ' 5 Ba = 137.1 B1 = 27'3 c = 12'0 N = 14.04 16.96 Y = 31'0 44 '0 AS = 75.0 45 -6 Sb = 120.6 87.4 - 2 x 43.7 I, = 208.0 0 = 16'0 16'07 S = 32.07 46 *7 s c = 78.5 49 -5 TC = 125.3 F1 = 19.0 16.46 c1 = 35.46 44 *Ell BY = 79'97 46 *S I = 126'8 16 *;i Si = 28.5 Ti = 48.0 42 '0 Zr = 90.0 47 *G Ta = 13'7.6 110 = 02 45 Vd = 137 47 T T = 154 'DZn = 55.1 49 -2 RU = 104.3 92.8 = 2 x 46 -4 Pt = 197.1 Fe = 56'0 48 '3 Rh = 104'3 92.8 = 2 x 4@4 Ir = 197.1 cu 63.5 44 '4 Zn = 65.0 46 *9 Cd = 111-9 88'3 = 2 x 44.13 Hg = 200.2 - Ag = 107.94 k8 = 2 x 44.4 A U = 196 *7 Sn = 117.6 89.4 = 2 x 4% P b = 207'0 S.I;. Chnelin, Hhd., 5 j Aiitl. i, 47 ff j Miinch. gel. Ann-850, Bd. 30, S. 261 272, abgedr. ; d i t n . Cltem. Pharm., 1838, 105) 187 ; J. DUWAS, C.r., 1837, t. $5, p. 709; auch AILIL. Cheub. Phcc,-)~z., 105, S. 74 u.a.TABLE V. I. -- - Li = 7 '01 ?Be = 9.3 11. -- B = 11.0 C = 11.97 N = 14.01 0 = 15.96 F = 19.1 Na = 22.99 Mg = 23.9 ~ ~______ 111.-- A1 = 27.3 Si = 28'0 P = 80.9 S = 31.98 c1 = 35-38 13 = 34.04 Ca = 39.9 IV. --- - Ti = 48.0 V = 51.2 Cr = 52-4 M n = 54.8 Pe = 55.9 Co = Ni = 58.6 CU = 63.3 Zn = 64.9 V. --- - - AS = 74.9 Se = 78.0 Br = 79.75 Rb = 85.2 Sr = 87.0 ~~~ ~ VI. -- - Zr = 89.7 Nb = 93.7 MO = 95.6 RU = 103.5 Rd = lW.1 Pd = 106'2 Ag = 107.66 Cd = 111.6 VII. -- 'In = 113'4 Sn = 117.8 Sb = 122.1 Te = 128? I = 126.5 CS = 132.7 Ba = 136 *8 VIIT. ---- - - Ta = 182.2 W = 183.5 0 s = 198.6: Ir = 196.7 Pt = 196.7 AU = 196 *2 HE = 199.8 W M U 1x. -- .. Pb = 206'4 e Bi = 207.5 Y1418 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. hydrogen-the atomic weights of which had been determined either by the aid of Avogadro’s law or the law of Dulong and Petit-could, together with the two elements beryllium and indium, be arranged in one table.I n this table, reproduced in Table V, it will be noticed that, as in its predecessor, the members forming the families are arranged in a horizontal series; there are many gaps which, aa Meyer points out, may be at some time occupied by those elements whose atomic weights had not yet been accurately determiued, and possibly by others yet to be discovered. Further, attention is drawn to the fact that the elements in the vertical columns IV, VI, and VIIT exhibit many relationships, e.g., isomorphism in certain of their compounds to the elements in the horizontal series immediately above. For example, titanium is so related to silicon and tin, vanadium with phosphorus and arsenic, chromium with sulphur and selenium, manganese :with chlorine, copper and silver with gold, zinc with magnesium and calcium.It is evident from this state- ment, and also from the table, t h a t Meyer fully appreciated the relationships in the properties of these elements upon which is based the division of the groups of elements into a main and a sub-group as i n the system adopted at the present time, namely, the more com- pletely extended one of Mendel6eff. Of Mendeleeff’s work in the same direction, Lothar Meyer was as fully cognisant as the abstract of the communication of the former, “ Veber die Beziehungen der E’igetaschaften IU den Atomgewichten der Elemente,” which appeared in the Zeitschrift fiir Chentie for 1869, could make him. In fact, Meyer describes his own table as in essence identical with that pub- lished by Mendeleeff, and further prefaces the statement respecting the series of relationships just referred to with the words: “ I will onEy add one remark to those made by Mendelheff in explanation of his table.” But, as it is not my intention to discuss any question of priority, but simply to lay before you an account of the part Lothar Meyer took in the development of this generalisation which has so pro- foundly influenced chemical thought, let us, therefore, return to other matters suggested by this paper “On the Nature of the Chemical Elements as a Function of their Atomic Weights.” The perusal of this work indicates that its author is inclined to regard its evidence of the probable composite nature of the elementary atoms, the existence of these relationships between the properties of the elements and their atomic weights, the interdependence between which he summarises by describing the properties of the elements as periodic functions of the attomic weights.To obtain a complete understanding of the nature of the elementsBEDSON : LOTHAR MEYER NEMORIAL LECTURE. 1419 in their dependence on the magnitude of their atomic weights, it is necesEary to follow step by step the changes of each property as we pass from element to element. The paper now under considera- tion, memorable as it is in so many ways, is especially so, in the example it affords of the first attempt to make such a detailed study Qf these cbangee. Lothar Meyer selccted for this purpose the atomic volumes of the elements, the relation between which and the atomic weights is depicted in a graphic representation, which shows tbe atomic volume to be a periodic function of the atomic weights, with regularly distributed maxima and minima.The curve which repre- sents these changes is dirided by five maxima into six sections, which .exhibit the form of a, series of chains placed in a line. There is 8 strong resemblance betwcen the second and third sections, and between the fourth and fifth sections. In the second and third sections, the atomic weight increases by 16 units in each, whilst iu the fourth and fifth the increase is approximately 46. The curve not only exhibits, as Meyer pointed out, the variation in the atomic volumes of the elements, but also indicates that the fusibility, volatility, malleability, brittlentsp, electro-chemical behaviour, and other physical and chemical properties alter in like manner, conse- quently the properties of an element are determined by its position on this curve.For example, the easily fusible, volatile, and gaseous elements are to be found on the ascending branches of the curve, whereas the infusible elements are found either at the minima or on fhe descending sections. The elements, therefore, whose molecules are easily separated from one another, would experience an increase in their atomic volume in passing by addition to their atomic weight into tho next element. Whereas the infusible and non-volatile elements, were i t possible too convert them into the neighbourirg element, by increasing their atomic weights, would suffer a, dimiuu- tion in their atomic volume.But the utility of this systematic study of the alteratiou in the atomic volume of the elements is not to be found alone in the bean- tiful epit,onie of the periodic law shown by this curve, but also iu the rcvelaticn of errors in the determination of the atomic weights of many elements, and of the indication of the piobable position in the “natural sjstem” of elements such as indium and thallium, so entirely justified by the results of subsequent investigation. In the conclusions set forth in this memoir are to be foulid the natural and independent consequences of the train of thought sug- gested by the cla~sification of the elements given in the first edition of the Jfodernen Theorien, they form a statement and amplification of the law underlying the relation between the properties of the elements and the atomic weights, showing how fully Lothar Metjer had grasped1420 BEDSON : LOTHAR MEYER MEMORIAL LECTURE, its meaning, and the justice of the action of the Fellows of the Royal Society of this country in awarding in 1882 the Davy Medal simul- taneously to Mendel6eff and Meyer, as founders of this great and important generalisation, the “ Periodic Law.” No one has shown his high appreciation of the labours of Mendelkeff in this domain of speculation more than Meyer himself, as a perusal of the Hodernen Themien, will show ; and in the lecture delivered at Plochingen, to which I have already referred, Meyer speaks of Mendelbeff’s brilliant contribution as forming I‘ the coping stone of the building which in the course of years has been erected on the foundation of Diibereiner’s Triads, of a work which did not, like Pallas Athene, spring ready armed from the head of a Jove, but has been gradually completed by the slow, painstaking, and often apparently vain endeavours of a whole series of workers.” The verification and justification of Mendel6eff’s boldly conceived use of this law have undoubtedly contributed to effect a complete change in the attitude of chemists toward speculations of this kind, and have served to awaken an interest in the labours of our fellow countryman, Newlands, the value of whose contributions we should all the rcore willingly recognise when we recall the unsympathetic reception they receired st the time, and the inappreciative remarks they called forth.The little reward obtained by the efforts of those who, prior to 1860, had devoted much time and ingenuity to the study of these relations, finds a ready explanation in the confusion which existed in the minds of chemists as to the meaning of the term “atom,” and the lack of agreement as to the definite representation of atoma. Many of the Fellows of this Society there are who art! able vividly to recall those times, and the tumult engendered by the contending systems ; others, again, less fortunate, perhaps, than they, entirely dependent upon the knowledge acquired from the records of the science, can only by the aid of the imagination attempt to appreciate aright the condition of chemical thought at that time.To many it will be difficult to conceive that almost half a century after Dalton’s atomic theory had been given to the world it should have been necessary for a speaker, at the memorable Conference of Chemists, held a t Carlsrnhe in September, 1860, to emphasise the inadmissibility of using more than one atomic weight for a given element, and to state that one value alone can be accepted as the true atomic weight of an element. Yet such indeed was the case, for, as Meyer himself tells us in the notes appended to Cannizzaro’s famous pamphlet, ‘‘ Di un Corso di l?iloso$a Chemica ” (which in 1891 he edited for Ostwald’s Chtmical Classics), that one of the speeches which greatly coniributedBEDSON : LOTHAR MEYER MEMORIAL LECTURE.142 1 to the advance of the atomic theory was t.hat delivered by Professor Odling, of which this thought was the burden. And whenonce we have realised something of the spirit of those days and the doubts and uncertainbies which must have reigned in the minds of many chemists concerned with the definition of the conception so important to the vitality and growth of our science, we shall the more readily appreciate the sense of peaceful security which the repeated reading of Cannizzaro’s pamphlet produced in Lothar Meyer’s mind. The discovery of the Periodic Law may assuredly be counted as one, perhaps not the least of the benefits which have followed from the explanation given by the great Italian chemist of the apparent contradiction between the law of Avogadro and that of Dulong and Petit. Many of Meyer’s and his pupils’ investigations were undertaken with the object of furthering the systematisation of inorganic chem- istry and placing this portion of the science in a position similar to that which obtains in organic chemistry.In a paper entitled “ Zur Systenzatik der anorgnnischen Chernie,” published in the Berichte of 1873, expression was given to the wish for a change in this direction, and his brother chemisfs were exhorted to undertake a careful and searching examination of the already known compounds of the diiferent elementaiy bodies, and to set on foot systematic investiga- tions of the compounds of the elements of the sevezd groups, and thus provide material for a ‘‘ comparative chemistry.” As a step in the direction of systematisation, Meyer, in this paper, shows how it is possible to deduce the composition of the oxides and hydroxides of the elements by a general formula, in which 2 represents the element, v the valencg deduced from the composition of its highest oxide, a number identical with that repre- senting the group in the natural system to which tlie element belongs for which to prevent confusion, the term .“ index of affinity ” is pro- posed, and n is a small whole number.Applying this to the members of the third series we obtain the following. n = 0 NazO Mgz02 A1203 Si204 P205 S206 C1207 n = 1 H2Na202 - H,Al,O, H2Si205 H2P206 H2S20; H2CI20e &c., &C. I n like manner, formula for compounds of lower stages of oxidation may be deduced by the use of forniula H2nX,0, + - 2, H2,,X20, + - 1, and so on.Amongst the immediate results of this appeal are to be counted the investigations of the chlorides and oxychlorjdes of molybdenum, H2nXaOV + nr V - 1 . V = 2 . V = 3 . V = 4 . V = 5 . V = 6 . V = 7 .1422 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. chromium, and sulphur undertaken by several of Meyer's pupils. TO these may also be added the investigations of Michaelis, which resulted in the discovery of the tetrachloride of sulphur ; the dissociation of the latter and the conditions under which i t is resolved into snlphur dichloride and cblorine afford another example of the influence of temperature on the valency exerted by any given element. In the irrational treatment of inorganic chemistry, as depicted in the majority of chemical handbooks, Meyer found a state of affairs similar to that existing i n organic chemistry, wliich 20 years pre- viously Laurent had so rigorously criticised in his Xe'thode de Chimie. To Xeyer the same causes appeared to be operative in retarding the progress toward the goal, the attainment of which would be the founding of a system of inorganic chemistry which " would not fear comparison with the thoroughly developed system of organic chem- istry." (Moden& Theories, p.170.) Meyer's lecture before the German Chemical Society, delivered in 1893, Ueber den Vortmg der anorganischen C'herizie nach dein Natfiir- Eichen. Systeme der Elernente, should surely contribute to place the " prize " more within our reach, fur in this diecourse he has shown how, by the adoption of certain " artifices " the natural system of the elements may be made the basis of a course of instruction in general inorganic chemistry.Not the least of the advantages of the method. of treatment described in this lecture are those which accrue from the insight afforded into the history of the foundation of modern chemistry, and the gradual manner i n which facts are laid before the student forming materials which serve to exemplify the lams of chemicaal combination Rnd the development from these of the mole- cular atomic theory. The student thus instructed, and having acquired an understanding of atomic weights is prepared for an explanation of the outlines of the natural system. This outline is gradually filled in, not by a description and illustration of the pro- perties of the elements and their compounds, group by group, but first by the facts brought t6 light in the study of the chief types of hydrogen compounds, and the subsequent rsystematic treatment of the elements forming the several groups or families in the " natural sy s tem." It must bo conceded that a student so instructed should form n higher conception of inorganic chemistry than many appear to do, and may possibly be inspired with the desire to devote his energies to add something which may help to make the system more perfect, for so suggestive a treatment could not fail to bring out with due prominence those poifits on which additions to our knowledge are so much to be desired.No account of Meyer's labours in the department of chemistryUEDSON : LOTHAR MEYER MEMORIAL LECTURE.1423 now under consideration would be complete without a reference to the work published by him i n conjunction with Professor Seubert in 1883, in which are given the results of a recalculation oE the atomic weights of the elements. The task was begun by Lothar Meyer himself in Eberswdde in 1867, and, after many years’ interruption, recommenced and completed, as stated above, with the help of Professor Seubert. To some perhaps the task Meyer imposed upon himself may appear an almost thankless one; not so, however, to Bleyer, who saw in the study of the modes of combination of the atoms “ a. new epoch in the history of chemical statics,” and in the study of chemical change the basis of the “ dynamics of the atoms.” To one so minded the reward for the unremitting labour, the time and energy consecrated to the work, would be found in placing upon a certain and sure foundation these fundamental constants, so essential t o tbc advancement of the mechanics of the atoms.The influence of Meyer’s training in mathematics and in mathe- matical physics is evinced both in his experimental work and in his writings, and is shown in the selection of the problems submitted to experimental inquiry, the successful solution of which is to be attri- buted to the happy conjunction of the mathematician with the experimentalist. This is especially true of the series of investigations on the molecular volumes of chemical compounds, which had its starting point in the results obtained by calculation of the molecular volumes of certain gases from Graham’s observations on the rates of ‘‘ transpiration.” From Graham’s results, Professor Oskm E.Meyer deduced the coefficients of friction for the 19 gases experimented on, and by the aid of the relation established by Maxwell between tho rate of transpiration or the coefficient of friction, the molecular weight, tlhe molecular velocity and molecular sectional areas, Lothar Meyer calculated the molecular volumes for these 19 gases. He dis- covered t h a t the volumes so obtained exhibit t~ ratio similar to that exhibited by the molecular volumes deduced for these gases by the aid of Kopp’s law, employing the atomic volumes calculated from liquid compounds; and he established the fact, that the molecular volume of a gas is the sum of the atomic volumes of its constituents.To institute a comparison between the values obtained for the molecular volumes in accordance with Kopp’s rules and those deduced from the coefficients of friction, the latter, which are purely relative values, were expressed in terms of the molecular volume of liquid sulphur diDxide. In 12 cases, the agreement between the two sets of values is satisfactory, as will be seen by an inspection of the following table in which are given the molecular volumes arrived at from the friction constants, and also those calculated from the molecular volumes of liquid compounds. The agreement is more complete1424 BEDSON : LOTHAR MEYER MBM9RIAL LECTURE. when, in the cases of nitrogen and hydrogen and the compounds containing these elements, the atomic volumes obtained from the friction constants are employed, as will be seen by a comparison of the values contained in the third column, in which the molecular volumes are calculrtted with these numbers. It is further worthy of remark that in the case of carbon monoxide and of carbon dioxide a greater concordance is observed between the molecular roluines based upon the friction constants, and the calculated values, when Kopp’s lower value for oxygen is used, that is, for oxygeir combined a8 i t is ill water, instead of the higher value for oxygen as it is assumed to be combined in the “ carbonyl ” group.1IiloleculaT Volicnzes of Gases. From friction. Oxygen .......... Nitric acid ........Carbon dioxide.. .. Hydrogen chloride. Chlorine. ......... Hydrogen sulphide. Methylic chloride. .. Ammonia ......... Sulphur dioxide.. .. Cyanogen ......... Ethylic chloride. ... Methylic ether . . ,. Air .............. Nitrogen ......... Carbon monoxide . . Nitrous oxide.. .... Methane.. ....... Ethylene. ......... Hydrogen ......... 1. 13.8 15.9 26-7 24.1 44.1 43.9 30.0 48.2 23.6 55.1 66.0 53.8 15.0 15.3 15.4 15.7 19.4 33% 6.0 Ctllculated by aid of Kopp’s numbers. 11. IIT. 15-6 15.6 14.5 15.5 31.0 26.6 28.3 25.8 45.6 45.6 42% 42.6 33.6 28.6 50.2 42 8 18% 16.7 56.0 56.0 76.3 59.8 62-8 47.8 - 15-0 4-6 15.3 23.2 18.8 16.8 27-5 33.0 23.0 4 . 0 34.0 11.0 6-0 7 Our interest in these results is due not alone to the fact that they contribute to the advancement of knowledge, but also that they are deductions from some of the valued experimental facts bequeathed to science by one of the founders of this Society and its illustrious first President, Thomas Graham.Lothar Meyer sought next to extend therJe observations on gases by determining experimentally the rates of transpiration of vapours ; the work was commenced in Carlsruhe, and continued in Tubingen,BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1425 the paper containing the results of the first stage of this inquiry being dated from the latter place. Tn the account given in the Armalen der Yhysik und Cheinie (N.F., 1879, 7, 497), the method of observation and the apparatus employed are described. The appa- ratus devised for this purpose is a beautiful example of the same inventive skill which characterises all Meyer's work, and compels our admiration.The rate of transpiration measured is that of the saturated vapour. A long series of experiments were made with benzene, showing (1) that in case of vapours the coefficient of fric- tion increases with a rise in temperature more rapidly than in the case of gases, (2) that the molecular volume of vapours is greater at lower than at higher temperatures, which is also true of gases. The careful and acarching criticism to which Meyer submitted the experimental data revealed the fact tbat the laws governing the transpiration of gases cannot without modification be applied to vapours, and that further information as to the influence of pressure and of temperature on the vapour of benzene is required.Empirically he arrived at an expression for the relation between the rate of transpiration and the pressure of saturated vapours. From the con- stancy of this quantity is deduced a relationship between the co- efficient of friction of benzene vapour, and possibly of all other saturated vapours ; namely, that the coefficient of friction is propor- tional to the square root of the tension of the vapour. In conjunction with 0. Schnmann and subsequently with V. Steudel, the rates of transpiration of a, number of fatty acids and their ethereal salts, and also of several series of homologous com- pounds were determined. The results of these extended observations show that in the majority of cases, homologous compounds have very nearly the same coetlicient of friction.The average values being for = 0*000142 Alcohols, CnHzn + 2O ............ Chlorides, C11E2n + ,Cl ........... 7 = 0*000150 Esters, CILHPll+ .............. = 0*000155 Bromides, C,H,, + ,Br .......... q = 0.000182 Iodides, C,,H,, + ,I .............. 'I = 0*000210 The influence of the nature of the atoms constituting the molecules is shown by a comparison of chlorides, bromides, and iodides of approximately the same molecular weight. The influence exerted by the iodine is found to be greater than that of the bromine, and this again than that of chlorine. The molecular volumes of these various compounds calculated from the friction constants exhibit, a proportionality to those values obtained from their molecular volumes in the liquid state. When the1426 BEDSON : LOTHAR MEYER MEMORIAL LECTURE.first of these value3 is expressed in terms of the moleciilar volume of sulphur dioxide, as was clone i n the case of the g:wes, the molecular volumes are then approxiniatelg half the molecular volumes f o r the 8ame compounds in the liquid condition. That these two sets of values should not’ be identical finds a ready explanation in the fact that the molecular volume of a liquid increases with rise of tem- perature, whereas that of a vapour decreases. Meyer further pointed out that in the case of the isomeric butyl compounds the sectional area of the molecnle of the tertiary isomeride is less than that of the corresponding secondary, and this again than that of the primary compound ; but he found no such regularity in the case of the isomeric propyl compounds.A notable feature in the several publications on this subject, is the nnbiassed freedom with which the experimental results are discussed, and the care which is taken to avoid too hasty “ generaliaation.” The difficulties of the solution of the problem of the influence of the several factors affecting the coefficient of friction of gases and its relation to the form of the molecules ars fully realised and appreciated by Meyer, who is careful to direct attention to many matters which need a searclhg experimental examination before the full and true meaii- ing of these phenomena is realised. The numerous publications of the pnpils of Lothar Meyer, emanat- ing chiefly from the laboratories of Tubingen, are of a, very diversified character. In the selection of subjects for investigation, and in the manner of execution, the influence of the master’s spirit is to be traced.The preparation of compounds, both in inorganic and organic chemistry, has added to the list of compounds already known ; the investigation of their modes of formation and properties has been so directed as to shed a light on points of general interest. The physical constants of many series of compounds have been revised, and our knowledge of the relation between the physical pro- perties and the composition and constitution of compounds received extension. That interesting class of chemical changes usually described rts ‘( contact actions ” has been submitted to careful and critical examina- tion, and our knowledge of “oxygen carriers” and of “chlorine carriers ” and their mode of action very materially advanced. Measurements of the influences of mass, time, dilution, and of other factors in a variety of instances of chemical change, have added many new examples of the truth of the law of Guldberg and W aage.This mere recital of the themes affords evidence of the undoubted attraction which the more theoretical side of chemistry had for Meyer, and at t’he same time show how strong was the desireBEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1427 which animated him to aid in the ordering of the facts of chemistry and thus to contribute to the building up of a system of chemical philosophy. We are also indebted to Meyer for many laboratory appliances, S O R I ~ of which are incidentally mentioned i n the description of the results OP $01118 investigation, others again have formed the subject of special memoirs.The paper on “ Air Baths ” affords ample evidence of his ingenuity in devising apparatus, and also shows that by strict attention to scientific principles grertt efficiency can be combined with economy in fuel. In addition, the exact analysis of gases has been simplified by the apparatus devised by Lothar Mejer and K. Seubert, an account of which formed the subject of a paper con. tributed to the Transactions of this Society. At the same time Meyer drew attention to the advantages in the calculations of the results of gas analysis, which is secured by a stiict adherence to. Avogadro’s law. I n the history of the progress of theoretical chemistry during the past 30 years, the name of Lothar Meger must occupy a foremost position.To the advancement of chemical theory he not only con- tributed as r2 founder of the natural system of the elements, but also as an exponent of the speculations and theories, whether in chemistry or physics, which have combined to awaken an interest in those problems of physical chemistry, the solution of which will bring nearer the redisation of Berthollet’s ideal, a chemical philosophy based on the general laws and principles of mechanics. The first edition of Die Modernen I’heorien was written not alone for chemists, but also to make known to other scientific investigators the nature of the hypotheses and theories forming the basis of chemical philosophy at the time.The time of publication of this work, namely, 1864, was indeed opportune, following as it did immediately on the acceptance by the majority of chemists of the new atomic weights. It marks an epoch in the growth of the atomic theory ; the terms ‘‘ atom ” and ‘‘ molecule ” had at length acquired a distinct, and definite meaning. The publication of a book dealing solely with the theories of chemistry was a matter of great moment in its history, not to be undertaken in a light spirit, nor did Meyer approach the enterprise in any such mood, for only after it had practically been rewritten for a third time was the manuscript handed to the printer. Despite the labour and time expended on this work, the final step was taken with serious doubts as to the value and utility of if, and whether even its usefulness would prove a sufficient excuse for the violation of the accepted traditions of his co-workers in chemistry.These tradi- tions allowed the indulgence in theoretical speculations, when these1428 BEDSON : LOTHAR NEYER MEMORIAL LECTURE. appeared-one might almost say-as addenda to the results of experi- mental inquiry. This attitude of chemists to theoretical speculation suggests that in some occult way they had inherited that contempt for theory which Mephistopheles sought to im.plant in the mind of the pupil of the alchemist Faust. (( Grau, theurer Freund, ist alle Theorie.” This disregard for hypothesis and theory is as little to be justified as is the other extreme. Chemical literature contains many ex- amples of both faults, and certainly many oE the text-books of the science would be better for the infusion of the quickening influence of chemical philosophy into the dry bones which masquerade as a portrayal of the science of chemistry.Lothar Meyer’s book has undoubtedly contributed to effect a change in this direction, and has also led to a more just apprecia- tion and recognition o€ the truths contained in the hypotheses of Avogadro and of Dulong and Petit. At the time when this book appeared, Arogadro’s law was by some regarded as purely arbitrary, the adoption or rejection of this hypothesis was considered of little import ; it received allegiance from others on purely chemical con- siderations. To such the exposition given by Meyer of the applica- tion of these hypotheses in the determination of the atomic weights of the elements, the agreement in the deductions arrived a t by assistance, and the necessity of Avogadro’s hypothesis recognised by Clausius on purely physical grounds, to which Meyer directed atten- tion, must have proved convincing and have serred to elevate these laws to a position of regard higher khan that they had previously en joyed.The feature of the teaching of this work, summarised as we find it in the extended title Die 2l.lodernen Theorien der Chemie und ihre Bedeutung fur die cheniischen Statik is that which gives the distinc- t,ive character to the book. The determination of the atomic weights and the methods used become important, inasmuch as they are concerned with the measurement of the relative masses of the atoms, the invariable quantities, the constants of a theory of the statics of the atoms.The additional property of the elementary atoms, revealed by the consistent use of Avogadro’s law, the specific quality which determines the atom-fixing power of an elementary atom, is studied in the light of an extension of this theory ; and the forrnulm employed to show the constitution of molecules become representa- tions of the equilibrium of the atoms. The discovery of this pro- perty marks a new epoch in the history of chemical statics. To the interpretation of the constitution of solid compounds whose molecular weights cannot be directly ascertained by Avo- gadro’s law, this atom-combining power is extended, but not withoutBEDSON : LOTHAR MEYER NEMORIAL LECTURE.1429 due caution as to the uncertainty surrounding the conclusions drawn. The physical pyoperties of compounds are discussed and interpreted in the light oE the new doctrine of valency, and finally this doctrine is applied to the classification of the elements in the mauner I have already described. With the appearance of the second edition, which was published in 1872, the book altered somewhat in character, the 147 pages of the first edition having grown into 364 ; this addition, in part due to the incorporation of empirical data illustrative of the theories, in part also, to the somewhat lengthy discussion and illustration of the laws of atomic linking, which the development oE organic chemistry and of the benzene derivatives necessitated ; and, finally, to the inclusion of an account of the notable additions made to our knowledge of the “nature of the chemical atoms,” which the speculations of Meyer and of Mendeleeff had revealed.To Meyer himself the second edition had assumed greater import- ance than its predecessor, and he ventured to dedicate i t to his honoured master, Bunsen. The third edition, published five years after the second, is not very materially different from the latter, although it contains an important contribution to the study of the nature of valency, in the recognition ot the fact that the valency of an element may be influenced by the nature of the atoms with which it combines. Thus chlorine, bromine and iodine act as monovalent elements in their compounds with the more electropositive elements, such as hydrogen and the metals ; whereas to oxygen and other electro-negative elements they comport themselves as polyvalent, and, possibly, heptavalent elements.In the fourth edition, which was published six years after the third, and followed by a fifth a year afterwards, the HoderrLen Tlieorien underwent a very material alteration. To the discussion of the problems of chemical statics, which had been treated in former editions, a special part was added concerned with the pheno- mena of chemical change, and the influence of external agents in promoting or retarding chemical action. This third section deals with the “ Dynamics of the Atoms,” thus giving completion to the thought suggested by the earlier editions of the publication of a work which should form an account of ‘‘ Chemical Mechanics.” The translation of the fifth edition of this work by ProfeBsor Williams and myself, which appeared in 1887, found so ready a sale that in three years the edition was exhausted, a fact which surely justifies the belief that the book is so well known amongst chemists as to preclude the necessity of an attempt to sketch in out- line the contents of the third section of the work.The 20 years that have elapsed since the first appearance of Meyer’s Moderneit VOL LXIX. 5 D1430 BEDSON : LOTHAR IfEYER MEMORIAL LECTURE. Thwrien have witnessed great changes in the attitude of chemists towards hypotheses and theories ; a change which in some quarters has led to the institution of a comparison between the modern school of chemists and those of the classical school, not altogether favour- able to the former. Be that as it may, there can be no doubt as to the advantages chemistry has already derived from the acceptance of the kinetic theories of the states of aggregation, of the kinetic theory of electrolysis of Clausius, and of Guldberg and Waage’s theory of the action of mass; the necessity for some such hypotheses was pointed out by Meyer in the first edition of this book in the following passages.“ It will be necessary in the immediate future to introduce some new hypotheses. It sppears that many of the fields of molecular physics which are closely allied to, and are in the almost exclusive possession of chemistry, cannot be successfully cultivated at present without the theoretical speculations and hypotheses advocated by Clausius, which represent the different conditions and forms of matter as determined by the various forms of motion of the corporeal molecules.“ These views, based on the fundamental principles of mechanics -and especially the mechanical theory of heat-alone appear capable of penetrating into the influence which the chemical nature of bodies -the atomic constitution oE their molecules-exerts on the changes of the states of aggregation, e.g., fusion :and solidification, evaporatioii and condensation; on vapour pressure, and on the phenomena of diffusion, absorption, solution, crystallisation, endosmosis, and all similar processes. The theoretical investigation of electrolysis and of the whole field of electro-chemistry can only be successful from this side.In the consideration of all purely chemical reactions, chemical decompositions and chemical combination, such conceptions may become indispensable, in fact very similar ideas have been sug- gested by the consideration of purely chemical phenomena.” The fulfilment of this prediction has not yet been followed by the complete alteration in the old conception of “ aEnity ” as an attractive force, a change also foreshadowed in the early editions of the Nodernen Theorien. The causes which have been operative in retarding this advance in our conception of aEnityare found in the absence of kinetic Speculations on the thermal changes accompanying chemical phenomena. The discussion of the vast accumulation of thermo- chemical data from such a standpoint, as suggested by Meyer, not only in the last edition of the dlodernen Z’heorien, but also in the article published in 1883 in the AnnuZen 011 the “ Basis of Thermo- chemistry,” and, again later, in the contribution to the Zeit.physi- kal. Chem., entitled the “Evolution of the doctrine of Affinity,”BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 143 1 must bring nearer the realisation of a kinetic theory of chemical affinity. Amongst the last undertakings of Meyer’s active life was the pre- paration of a sixth edition of this work, which has played 60 importatit a part in directing attention to the theoretical side of the science of chemistry, and also in arousing an interest in the border- land between chemistry and physics, now cultivated with such zeal and enterprise, and with results so full of promise.Lothar Meyer had repeatedly declined to undertake the task of preparing a new edition of the Moderrt Theories, and when I ap- proached him, in 1890, he suggested that Professor Williams and I should prepare a translation of the smaller book which bad just appeared. In Germany two editions of this book have been published, mid it has also been translated into Russian. When, two years ago, I again wrote to LotharMeyer on the subject of a new edition OF the Modern Theories, he replied that he had declined the invitation of his publishers, feeling that “ it would be tempting fortune to undertake the republication of a work which had been so long before the public.” He expressed himself as “ perfectly content with the influence which it bad exercised in the chemical world,” but felt that a new edition must either be made much shorter or more extensive, and, foreseeing this, he had written the smaller one, namely, The Oz&Gaes of Theoretical Cheniislry .He con- tinues in his letter, “ The world desires at the present time numbers and formulae, and is no longer thoroughly alive to the philosophy set. forth in the Modern Theories.” This decision was, however, overruled, and, on the day of his death, Meyer had completed the manuscript for Book I of the sixth edition, which has since been published, with a preface, by Professor 0. E. Meyer, who has justly described i t as “ an interesting mono- graph on the atoms, of permanent value in itself.” Meyer’s labours were not entirely confined to matters of a purely scientific character.Like many distinguished chemists in this country, he took a great interest in questions relating to education, and contribnted many articles to magazines, $c., on this subject. We are so much accustomed t o look to Germany as the ideal of systematised educatioii, that we are scarcely prepared to see the faults which Lothnr Meyer detected. The difference iu standpoint sufficiently explains the direction of attack. The authorities of the German Universities have, from the first, recognised the equality of all branches of knowledge, and their right to it just recognition in all University education. Further, the rewards and degrees dispensed by them are not to be gained through the single avenue of examination and knowledge of the known, but evidence of 5 ~ 21432 BEDSON : LOTHAR METER MEMORIAL LECTURE.ability to utilise the known and to extend the hounds of know- ledge is demanded from their graduates. How beneficial this attitude has been to the development of the industrial enterprises of Germany is thoroughly understood by chemists. Hence Meyer was not concerned with the problems of technical education as we understand them in this country, but rather with the training of those who were to become students of chemistry in the Universities. For such he advocated a broad and liberal school training in mathematics and languages, and did not wish to see the time and training, which should be devoted to these fundamental subjects, curtailed by instruction in special branches of science carried to such n degree that, when the student comes to the University lecture-room, the subject has lost all its freshness and attractions for him ; and he regards attendance at lectures as a waste of time, and nothing less than eine Arbeit will satisfy him in the laboratory.In England we may surely learn much from such suggestive thought ; let the Universities demand, aa Meyer advo- cated for Germany, evidence of n sound, liberal training before the student matriculates. Once matriculated, permit the undergraduate to pursue some well-defined course of special stildy, and ask a s evidence of the result of such work, not the performance i n an examination hall, but some contribution to chemical knowledge.The industries would then, as in Germany, look to the Universities for the thoroughly traiiied chemists to assist in their direction, aud provide the scientific labour which must form a prominent feature in future chemical industrial enterprise. Learned Societies in Germany, in this country, and in Russia have, like our own, sought to honour themselves by placing the name of Lothar Meyer on the roll of their distinguished members, and, with ns, deplore the loss of one whose thought has left i t s impress on the annals of science, and who has shown by experi- mental work, distinguished alike by the conception, the execution, and the lucid description of resnlte, how best the boundaries of knowledge may be extended. The following list of the published works of Lothar Meyer and of his pupils is taken from Professor Senbert’s account of the life of Meyer (Ber., 1895, 28).I. l.-Die modernen Theories der Chemie und ihre Bedeutung fur die chemische Statik. Breslau. Mmuschke and Berendt. Five editions j 1864, 1872, 1876, 1883, and 1884. a.-Grundziige der theoretischen Chemie. Leipzig. Breitkopf and Hertel, 1890. Second edition, 1893. (Translated into English and French.) (Ti.anslated into English and Russian.)BEDSON : LOTHhR MEYER MEMORIAL LECTURE. 1433 3.-L. M. und Karl Seubert. Die Atoiiigewichte der Elemente aus den Original- zalilen neu berechnet. Leipzig. Breitkopf and Hartel, 1883. 4n. -Abriss eines Lehrganges der theoretischen Chemie, vorgetragen von Prof. S. Cennizzsro. Herausgegeben Ton Lotliar Meyer. Ostwnld’s h’lassiker CJP,.exacfen Wissenschaffen. No. 30. Leipzig. Wilhelm Engelmann, 1891. Abhantl- lungen von J. W. Dobereiner und Max Pettenkofer, nebst einer geschiclit - lichen Uebersicht der Weiterentwickelung der Lehre von den Triaden der Elemente. Edited by Lothw Meyer. Ostzoald’s Klassiker der exncf en 7Vis.Yenschnj’ten. No. 66. Leipzig. Wilhelm Englemann, 1895. 4lr.-Die Anfange des naturlichen Sptemes der chemischen Elemente. 11. Chemical Papers a d Dissertations of his. PwpiIs. 1857. 1858. 1862. 1863. 1864. 1565. 1866. 1867. 1870. 1871. 1872. 5.-Ueher die Gase der Blutes. Inazig. Diss., Wiirzburg, 1857; Hej21p und Pfeufw’s Zeitschr. f. m f . X e d . [N.F.], 8, 256. Abstract, Pogg. Annale,i, 102, 299 ; Phil. Mag., 1857, 14, 263-268. 6.-De sanguine oxydo carbonic0 infecto.Diss. Aug. Vratisl, 1858. Ueber die Einwirkung des Kohlenoxydgases nuf Blut. Henle v n d Pfeufer’s Zeitschr. f. mt. Med. [N.F.], 9, 83 ; Schmidt’s Jahrb.f. d . yes. Med., 101, 22. Pogg. Annalen, 104, 189 ; Liebig’s Annnlen, 110, 312. Ueber die Absorption der Kohlensaure durch Losnngen des neutralen Natronphosphates. Studien des physiol. Insf. zu Breslaic. Heft 2. Leipzig, 1863. Abstract, Liebi-9’s Annnlen, Suppl. 11, 157. Pogg. Annalen, 120, 605. lO.-Bequeme T‘orrichtung ziir Reinigung des Quecksilbers. Zeit. ancri. Il.-Gasometrische Bestimmung der Kohlensiiure in Mineralwassern. 2 p i t . y . 12.-Ueber die Hofmann’sche Reaction auf Tyrosin. Liebig’s Aniznlea, 13.-Chemische Untersuchnng der Thermen zu Landeck in der Grafachn ft 14.-Ueber die Umkelwung der Natriumlinie.Zeit. Chein., 1865, 464. 15.-Ueber die Beziehungen der Specifischen Wiirme zum Atom- uild 16.-Ueber einige Zersetzungen des Chloriithyls. Liebig’s Annalen, 159, 17.-Ueber die Molekularrolumins chemischer Verbindungen. Liebig’s 18.-Die Natur der chemischen Elemente als Function ihrer Atomgewichtr. 19.-Ueber die Apothese Avogadro’s. Ber., 4, 25. Isomorphie von 20.-Apparat zur Regulirung des Luftdruckes der Destillationen. Be?.., 5, 7.-Wirkung des Drucks anf die Verwnndtschaft. 8.--L. M. und Rud. Heidenhain. g.-Krystallform des Desoxylsiiureathplathers. Chem., 2, 241. anal. Chem., 2, 237. 132, 156; Zcifs. onnl. Chem., 3, 199. Glatz. J. pr. C7~em., 1864, 1. Phil. Mag., 30, 390. Molekular-gewicht. Zeit. Chem., 1865, 250. 2s2. Annalen, Suppl. v, 129.Lie6ig’s Antialen, Suppl. VII, 354. Natronsalpeter und Kalkspath. 804. Ref. J.pr. Chena., 1864, 4’76-501. Ber., 4, 53. 1S73. 21.-Bcschreibmg eines Druckregulstors. Liebig’s Annnlen, 165, 303.1434 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1873. 22.-Ueber das Atomgewichte des Molybdins. Liebig’s Annalen, 169, 360. 1875. 24.-Vorlesungsversuch uber Verdampfung oline Schmelzung. Ber., 8, 23.--Bur Systematik der anorganischen Chemie. Ber., 8, 1627. 1627. 25.-osc. Brenken. Ueber Chlorjod. Ber., 8, 487. 26.-Pet. Melikoff. Ueber die Dichte des aus Dreifachchlorjod entstehenden Dampfes. Ber., 8, 490. 1876. 27.-Wasserstoffentwickelung durch Zink und Kupfersulfat. Ber., 9, 512. 18’77. 28.-Ueber Dreifachchlorjod. Ber., 10, 648. 29.-W. Bornemann. Ueber Chlorjod, Bromjod, Chlorbrom und dercn Yerhalten gegen Wasser.Ina.;E/. Diss., Tubingen, 1877. Liebig’s Annalen, 189, 183. 30.-Ueber unvollstiindige Verbrennung. 31.-Emil Elsasser. Ueber eine Elektrolyse mit Wasserstoffentwickelung 32.-otto Schumann. Ueber die Affinitiit des Schwefels und des Saner- Ueber die Einwirkung von Wasserdampf nuf gluhende Ber., 11, 206; ?Vied. dmnlen, Ber., 10, 2117. an beiden Polen. stoffs zu den Metallen. Holzkohlen. Liebig’s Annalen, 192, 288. Ber., 10, 1. Inaug. Diss., Tiibingen, 1877. 1878.-33.-Jolin H. Long. 34.-Ueber Transpiration von Dampfen. 35.-Ueber das Atomgewichte des Berylliums. 3B.-Ludwig Schreiner. CTeber die Siedepunkte der Estei. nnd Aether- Ester des Oxysiiuren. Inaug. Diss., Tubingen, 18’78 ; Liebig’s Annalen, 197, 1. 37.-Georg Pratorius.Ueber die Salze der Chlorcliromdnre. Innug. Diss., Tubingen, 1878 ; Liebig’s Annalen, 201, 1. 38.-Hans Settegast. Beitrage zur quantitatiren Spectralanalyse. Inniig. Diss., Tubingen, 1878 ; Wied. Annalen, [2], 7, 242. 39.-Wilh. Pu ttbach. Ueber Moljbdanacichloride. Inaug. Diss., Tubingen, 1878 ; Liehig’s Annalen, 201, 133. 40.-Friedr. Clausnizer. Ceber einige Schwefeloxychloride. Inaztg. Diss., Tubingen, 1878. 1879, 7, 497. Ber., 11, 576. Der., 11, 2007, 2009, 2011, 2012. 1879. 41 .-Reinigung des Quecksilbers. Bei-., 12, 437. 42.-Jul. Schuncke. Ueber die Losliclikeit des Aethyloxydes in Wassci- und wassriger Salzsiiure. Inaug. Diss., Tubingen, 1879 ; Zeit. physikal. Chein., 14, 331. 43.-James Morrie. Ueber den Einfluss der Mame auf cheniischen Um- setzungen.Inaug. Uiss., Tubingen, 1879 ; Liebig’s Anitden, 213, 253. 44.-J. H. Long. On the diffusion of Liquids. Inaug. Diss., Tubingen, 1879; Wied. Annalen, 9, 613. 4,5.-Emil Elsiisser. Ueber Galvankche Leilung von Metalllegirungen. Wied. Annalen, 8, 455. Ber., 13, 220, 259, 2043. 1880.-46.-Zur Geschichte der periodischen Atoniistik. 47.--Zu Tictor Meyer’s Dampfdichtebestimmung. 48,-Ueber das Atomgewichte des Beryllinms. 49.--Verdampfung ohne Schmelzung. 5O.--Paul Schoop. Ber., 13, 991. Ber., 13, 1780. Ber., 13, 1831. Die Aenderung der Dainpfdicliten bei variablem Druck Inntry. Diss., ‘I‘iibin;eu, 1880 ; Wied. und varjabler Tempemtur. Aitnalen, 12, 550.BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1435 1881. 51.--Verdampfnng ohne Scbniclzung. Ber., 14, 718. 52.-L. M. und Otto Schumann.Ueber Transpiration von Dampfen. Ber., 53.-otto Schumann. Ueber Transpiration von Dampfen. T i e d . Annaleiz, 54.-Eniil Elshser. Ueber die Specifischen Voluniina des Esters der Fett- reihe. &.--l(onr. Bbtsch. Unvollstiindige Verbrennung yon Gasen. Inaug. Dis.~., Tubingen, 1881 ; Liebig’s Annalen, 211, 207. 56.-Alb. Holzer. Ueber einige Phenolather. Inaug. Biss., Tubingen, 1881. 57.-Eug. Sapper. Ueber die Einwirkung der Halogenwasserstoff e auf Znsammengesetzte Aether. Inaug. Diss., Tubingen, 1881 ; Liebig’s Annalen, 211, 1’78. 58.-TLeod. Lehrfeld. Ueber die Einwirkucg von Ainmoniak auf Bibrombernsteinsaure und anf Bibrombernsteinsknreathylester. Inaug. Diss., Tiibingen, 1881. 14, 593. 12, 40. Inau.g. Diss., Tubingen, 1881 ; Liebig’s rlnnalen, 218,302. Ber., 14, 1816.1882. 59.-Ueber die Bildung und Zervetzung des Acetanilids. 60.-L. Gordon Paul. On the identity of certain mixed Ether3 of Oxalic Acid. Inaug. Diss., Tubingen, 1882. 61.--Victor Steudel. Ueber Transpiration yon Dampfen. 1Tnaug. Diss., Tubingen, 1882 ; T i e d . Annalen, 16, 369 ; see also Lolhar Meyer, Ivied. Annalen, 16, 394. 62.-Ernst Noack. LTeber die Phenylester der Phosphorigen Saure. Inaug. Diss., Tiibingen, 1883 ; Liebig’s Annalen, 218, 85. 63.-Georg Kumpf. Ueber Nitrophenyl-Benzyl- und Nitrophenyl-Nitro- benzylather und die Nitrirungsproducte dea Benzylchlorids. Inaug. Biss., Tubingen, 1882 ; Liebig’s dnnalen, 224, 96. Ueber den Austausch von Chlor, Brom, und Jod zwischen organischen und anorganischen Verbindungen. Innug. Diss., Tubingen, 1882 ; Liebig’s Annulen, 225, 146.Ber., 15, 1977. 64.-Rich. Brix. 1883. 65.-Ueber Luftbader. Ber., 16, 1087. 66.-Die Grundlagen der Thermochemie. 67.-Paul Spindler. Der Nitrirungsprocess der Benzolderivate. Inaug. Bi.s.s., Tubingen, 1883 ; Ber., 16, 1252. 68.-Paul Frische. Ueber Nitrite p-Kresyl-Benzyl- Aether. I~Mzu~. Diss., Tiibingen, 1883 ; Liebig’s A m d e n , 224, 137. 69.-Martin Rapp. Ueber die Phenyl- und Kresylester der Phosphoraiiure und ihre Nitrirung. Innug. Diss., Tiibingen, 1883 ; Liebig’s Annalen, 224, 156. 70.-Benj. Kiihnlein. Eine hequeme Darstellung der Psraffine. Com- municated by Lothar Meyer. 7l.-Benj. Kohlein. Ueber die Austausch von Chlor, Brom, und Jod zwischen anorganischen und organischen Halogenverbintlungen. Inaug. Diss., Tubingen, 1883 ; Liebig’s Annalen, 225, 171.Liebig’s Amalen, 218, 1. Ber., 16, 560. 188.1. 72.-Ueber einen empfindlichen Thei*moregulator. Ber., 17, 47’8. 73.-Ueber dethereeter der GlycolePure. 74.-Ueber die Berechnung der Gnsanalysen. ’75.-L. M. und Karl Eeubert. Ber., 17, 669. Liebig’s Annalen, 226, 115. On the calculation of Gas Analysis. Ueber Gasanalysis bei starkvermindertem Diwck. Liebig’s Annalen, 226, 87. Gas andysis under greatly reduced pressure. J. Chem. ROC., 45, 601. J. Chsm. SOC., 45, 581.1436 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1884. 76.-Alfr. G. Page. Ueber morganische Chloride als Chlorubertrager. Inaug. Diss., Tubingen, 1884 ; Liebiy’s AnnaZen, 225, 196. ’77.-Ad. Scheufelen. Ueber Eisenverbindungen als Bromubertrigey. Inauy. Diss., Tubingen, 1884 ; Liebig’s AnnaZeti, 225, 196; 231, 152.78.-Aug. F6lsing. Ueber einige Aetherester cler Glycolskure wid Salicpl- siiure. Inaug. Diss., Freiburg, 1 B., 1884. Abstract communicated by Lothar Meyer. Compare also the note, Ber., 17, 669. Ueber die Siedepunktsanoinalien der chlorirten Aceto- nitrile nnd einige ihre Abkommlinge. Inaug. Disz., Tubingen, 1884 ; Liebig’s Annalen, 229, 163. 80.--6. Schlegel. Ueber die Verbrennung yon Kohlenwasserstoffen, ihren Oxyden und Chloriden mit Chlor und Sauerstoff. Liebig’s Annalen, 226, 133. Ber., 17, 484 and 486. 79.-Herm. Bauer. 1885. 81.-Ueber Chlor- und Brom-ubertrkger. Ber., 18, 2C17. 82.-Eisenchlorid nls Jodubertriiger. 83.-L. M. und Karl Seubert. Ueber die Einheit der Atomgewichte. Ber., 18, 1089. On the unit adopted for Atomic Weights.J. Chem. SOC., 47, 426. Das Atomgewicht des Silbers und Prout’s Hypothese. Bet-., 18, 1098. The Atomic Weight of Silver and Prout’s Hypothesis. J. Chew. SOC., 47, 434. Ueber Bromonitrophcnole, Bromonitrqphenetole, nnd deren Amidoderivate. Inaug. Diss., Tiibingen, 1885 ; Ber., 18, 611. Ueber den Austausch von Chlor, Brom, und Jod zwischen organischen u n d anorganischen Halogenverbindungen. Inaug. Diss., Tubingen, 1885 ; Liebig’s Annaleiz, 231, 257. Ueber die Einwirkung vcm Halogenrerhind~uigen des Aluminiuns auf Halogensnbstituirte Kolilenmasserstoffe. Inmy. Diss., fibingen, 1885 ; Liebig’s A?t?2aZen, 231, 285. Untersuchnngen uber den Einfluss der Masse rtuf die Chlorirung brennbarer Gase. Ijzaug. Diss , Tubingen, 1885. Liebig’s Annalen, 233, 1’72.Liebig’s linnnlen, 231, 195. 84.-L. M. und Karl Seubert. 85.-Joh. Lindner. 8G.-Heinr. Spindler. 87.-Conrad Kerez. 88.-Ad. Romer. 1886. 89.-Ueber die Verbyennung ~ o i i Kohlenoxyd. Ber., 19, 1099. 90.-Jul. Giersbach. Ueber die Nitrirung des Banzol. Tnatry. Diss., 91.-Emil Meyer. Ueber die Affinitac der Vitriolmelnlle Zuni Wasser. 1887. 92.-Die bisherige Entwickelung der Affinit8;tslehi.e. Zeit. physikal. Chenz., 93.-Ueber die Einwirkung von Chlorkohlenstoff anf Oxyde. Ber., 20, 94.-Apparat zur fractionirten Destillation Linter verniinderten Drucke. 95.-TyTeber Sauerstoffubertrager. Be?.., 20, 3058. 96.-Ucber die Darstellung von Jodwasserstoff. 97.-Ueber die Constitution des Benzols. 98.-Art,h. Kessler. Tubingen, 1886. Inaug. Diss., Tiibingen, 1886.1, 134; also Phil. Mag., 23, 504. 681. Bw., 20, 1833. Ber., 20, 3381. Liebig’s Annalen, 247. Die Nitrirung des Benzols in ihrer Abhangigkeit von Geki-onte Prei.wrbeif und Inaug. der Masse der wirkenden Stoffe. Diss., Tubingen, 1887.BEDSON : LOTHAR METIER MEMORIAL LECTURE. 1437 1887. 99.- Jul. Eisenlohr. Ueber Nitro- und Bromnitroderivate des Phenols. lOo,--Friedr. Neubeck. Ueber Molekularvolumina aroluatischer Verbin- Inaug. Diss., Tubingen, 1887 ; Zeit. physikal. Chcnz., 1, 101.-Rich. Fink. Vebcr die d5nitiit der Vitriolmetalle zur Schwefelsaure. 102.-Fr. Binnecker. Ueber verschiedene Metallsalze als Sauerstoff uber- I m u g . Diss., Tiibingen, 1887. dungen. 649. Innug. Diss., Freiburg, 1 B., 1888 ; Bet.., 20, 2106. trager an schweflige Siiure. Innug. Diss., Tubingen, 1887.1888. 103.-Ueber die Nitrirung des Benzols. Zeit. physikal. Chem., 2, 676. 104.-Osc. Burcharcl. Ueber die Oxydation des Jodwasserstoffes durch die Sauerstoffsauren der Salzbilder. Inaug. Dis.~., Tubingen, 1888 ; Zeit. physiknl. Chem., 2, 796. Ueber die Verwandtschaft der Schwermetalle zuin Schwefel. Inaug. Diss., Tubingen, 1888 ; Liebig’s Annalen, 249, 326. 106.--Ad. Mente. Ueber einige anorganische Amide. Inaug. Diss., Tubin- gen, 1888 ; Liebig’s Annalen, 247, 232. 107.-Alb. Bonz. Ueber die Bildung von Amid ttus Ester und Ammoniak und die Umkehrung diesel. Reaction. Inaug. Biss., Tiibingen, 1888 ; Zeit. physikal. Chem., 2, 865. 105.-Ernst Schurrnann. 1889. 108.-Ueber Nitrirung. Ber., 22, 18. 109.-Ueber Salpetersaureanhydride. Ber., 22, 23. 110.-Ueber die Umsetzung von Siiureamiden mit Alkoholen.111.-Nachtragliches uber Luftbader. 112.-Ueber Gasheizung. Ber., 22, 883. 113.-L. M. nnd Karl Seubert. 114.-Phil. Liihr. Ber., 22, 24. Ber., 22, 879. Die Einheit der Atomgewichte. Ber., 22, Ueber die Einwirkung von Alkyljodiden auf Cadmium Inaug. Uiss., Tubingen, 1889 ; Liebig’s AnTbah, Ueber die Molekularvolumina einiger Substitutions- Inaug. Diss., Tubingen, Zeit. physikal. Chem., 5, Ueber die Sulfurirung des Chinolins und des Phenols. 1891. 118.-Zur Theorie der Losungen. Sitztingsber. d. K. Preuss. Aknd. d. Wis- 119.-Wm. McKerrow. Zur Kenntniss der Bromubertrager. Inaug. Diss., 120.- W. Pullinger. Ueber Platin-Kohlenoxydverbindungen. Ber., 24, 121.-L. M. und Karl Seubert. Die Einheit der Atomgewichte. Phnrm.Wied. Annalen, 46, 166. TJeber den Umsatz von Wasserstoff mit Chlor und Inaug. Diss., Tubingen, 1892 ; Zeit. physikal. Chem., 9, Ueber die Zersetzung der Aether dutch Wasserstofi- 872 and 1161, 1392. und Magnesium. 241,48. IlL-Sigm. Feitler. . productt! aromatischer Kohlenwasserstoffe. 1889 ; Zeit. physikal. Ckem., 4, 66. 1890. 116.-Ueber das Wesen des osmotischen Drucke~ 23. ll$’.-Heinr. Pnlda. Inaug. Diss., Tubingen, 1890 ; Zeit. physikal. Chem., 6, 190. sensch. zu Berlin, 1891, 48, 993. Tubingen, 1891 ; Ber., 24, 2939. 2291. Rundschau, New York, 1891, 9, No. 4. 1892. 122.-Ueber den sogenaunten osmotischen Bruck. 123.-John A. Harker. Sauerstoff. 673. 124.-Walter Lippert.1438 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. siiuren. 148. 1892 ; Liebig’s Annalen, 276, 129. Inaug. Diss., Tubingen, 1892 ; Zeit. physikat. Chem., 276, 1892. %25.-Herm. Flech. Ueber Magnesium Alkyle. Inaug. Biss , Tubingen, 1893. l26.-Ein kleines Labatoriurnlufttherniometer. 127.-Ueber den Vortrag der anorganischen Chemie nach dem naturlicllen Sptem der Elcmente. Ber., 26,1230. 128.-Ueber die Kiihnlein’sche Darsteilung der Paraffine. 129.--Nachtrag zu der Abhandlung von A. Weigle. 130.-A. Mieigle. Bey., 26, 1047. Ber., 26, 2070. Zeit. physikal. C h e n ~ , 11, 426. Spectrophotometrische Untersuchung der Sdze aroma- tischer Basen. Inaug. Diss., Tubingen, 1896 ; Zeit. physikal. Chem., 11, 227. Ueber die Einwirknng von Chlorwasserstoffsaure auf Aethylalkohol. I w u g . Diss., Tubingen, 1893 ; Zeit. physikal. Chem., 12, 751. 132.-Rich. Theurer. Einwirkung von Salzsiiure auf einige Triphenyl- methan-Farbstoffe. rnaug. Diss., Tubingen, 1893. 131.-John C. Cain. 1894. 133.---Electrolyse der Salzsaure als Vorlesungsversuch. Ber., 27, 2766. Ber., 27, 850. 134.-Ueber Acetylen, eine Warnung. 135.-Ueber die Darstellung der Paraaine. 136.-Die niederen Para5ne. Aethan nnd Propan. Bet.., 27, 2767. 18f.-Ein Trockeiischrankchen &us Aluminium. 138.-L. M. und Karl Seubert. Ueber das Verhiiltniss der Atomgewichte des Wasserstoffs und Sauerstoffs. 139.-Fritz Klunge. Zur Kohlenlein’schen Darstellung der Paraffine. Inaug. Diss., Tiibingen, 1894; Lieb ig’s Annaien, 282, 214. 140.-Ad. Hainlen. Ueber Propan und Aetlian in flussigem Zuetande. Inaug. Diss., Tubingen, 1894; Liebig’s Annalen, 282, 229. 141.-C. Haacke. Spektrophotometrische Untersuchungen uber die Einwirk- ung von Salzsaure auf einige Substitutionsproducte dcs Fuchsins. Inaug. Diss., Tubingen, 1894. 142.-Fritz Woga. Ueber Magnesium-Diphsrigl. Inaug. Diss., Tubingen, 1894. Liebig’s Annalen, 282, 320. Ber., 27, 2766. Ber., 27, 7769. Ber., 27, 2’770. 1895. 143.-Die Constitution der Fuchsine. Ber., 28, 519. 144.-Otto Degner. 145.-Wilh. Ludwig. 146.-E. Manz. Ueber Isobutan, normales Butan, und Propylen in Itnug. Diss., Tubingen, 1895. Ueber gegenseitige Loslickkeit einiger nicht misch- Oekronte Preisarbeit, Tubingen, 1895. Ueber einige Aether des Triphenylmethans und Tritiitro- flussigem Zustande. baren Fliissigkeiten. triphenylmethans. Inaug. Biss. ’ 111. Misce1la’rLeou.s Articles. 147.--Zui* Erinnerung an Leopolcl von Pebal. Nekrolog. Be?., 1887, 20, 148.-Eugen Lellmann. Nekrolog. Ber., 1893, 26, R., 1033. 149.-Die Chemie in ihrer Anwendung auf Forstwirthschaft. Zeit. f. Forst- und Jagdweselz, 1867, 3, 312. 150.-Ueber die neuere Entwickelung der chemischen Atomlehre. Vortrag geldten zu Plochingsn, 25 January, 1885. Boklen’s Nath.- nafww. Mitth., 3, 24 pp. R., 997.COMPOUNDS OF NATURAL YELLOW COLOURIKG MATTERS. 1439 1895. 151.-Ueber den Vortrng der anorganischen Chemie nach dem natiirlichen System der Elemente. Vortrag gehalten in der deut schen chemischerr Geeellschaft zu Berlin, 20 Mai, 1893. 15,”.--Ueber natur~issenscliaftliche Weltanschauurig. Rede am Gebiirtsd feste S. &I. des Konigs geiialteii Tom derzeitigen Rektor L. b L 27 February, 1805. Tiibingen. Ber., 26, 1230. 153.- ‘ I Allotropy.” 154.-Kritiken und Biicheranzeigen. Article for N’ntt’s Dictroiiary, 1885, 1, 128-131. Zeit. f. Chem. Juhrg., 1865-1868, Articles O ~ L Education. 155.-Die Zukunst der deutschex Hochschulen und ilwer Vorbildungaan- stalten. Breslau. Maruschke and Berendt, 18’73. 156.-Akademie oder Unirersitat ? Den deutsclien Forst,- und Land-wirtheu gewidniet. Breslau. Marusclike and Berendt, 1874 157.-Ueber akademische Lernfreiheit. Vortrag in der Dienstags-Gesela schnft zu Tiibingrn, 2.5 Februar, 1879. X o i d uizd Biid, Jahy., 1879, 158.-Uebtr die gewerbliche Schulfrage, Verhandl. d. Centralverb. Dd Industr. Versamml. in Niirnberg, 18 September, 1882. Ber., 8. 98. 159.--Matlematik und Naturwissenschaften in der Einheitsschule. Schriftew de.9 D. Ein~eitaschulcereinb, Heft 1, 1887. 160.--I)ie Reform der hoheren Schulen. 181.-Wunsche fur den niathematischen wid n:! turwissenschafrliclien Unter- rich2 an Gymnasicn. Lrhlig7s Zeilschr. Uas huntanistische Gym- nnsiurn. Jalwg. 1. DaselbPt, Heft 6, 1890. 162.--Die Vorbililung der Sfudirenden. X o , d i t i d Siid, 58, B e f c 172, 57.