J ~ N JAKOB S BERZELIUS RUDOLF WINDERLICH Oldenburg i./O., Germany (Translated by J. M i c h a e l Moore, M u h l e n b e r g College, Allentown, Pennsylvania)
"It i s amazing how this man labored and what he accomplished. How many things has he not observed and written about that nowadays reappear under the guise of new facts and new ideas."-Friedrich WLihler to Justus Liebig, GLittingen, June $4, 18.99.
TEE LIFE work of J. J. Berzelius, the great
Swede, is of such a far-reaching nature that his fellow-countryman, H. G. Soderbaum, in Brugge's "Book of Great Chemists" discussed only Berzelius' law of definite proportions instead of taking up briefly his life and works as a whole (1). At the same time, however, Soderbaum published a three-volume biography of Berzelius ($), which, since it is written in Swedish, is not too readily accessible to the average person. In spite of this difficulty and in commemoration of Berzelius' death one hundred years ago (Aug. 7, 1848) we shall attempt to gather the most important information dealing with those principles that still hold true today. Jons Jakoh Berzelius was born on March 20, 1779, in Vafversunda (East Gotland). His father was a schoolteacher in Linkoping. He died four years after his son's birth, and his mother a few years later. Thus young Berzelius was forced to earn his living from hoyhood. With only one exception his professors a t the gymnasium poked fun at him and his early interest in nature, and upon his graduation they characterized him as a person endowed with great natural abilities, but also as one whose bad habits rendered all hopes doubtful that one might otherwise cherish for his future. He studied medicine at the University of Upsala, but met there with no advancement. Toilsomely he had to make his own way through life. Afzelius, his professor of chemistry, permitted his students to use the lahoratory only once a week. He was incapable of producing oxygen. I t was Berzelius, who, to everybody's surprise after secretly conducted experiments, successfully demonstrated this art (5). During the summer of 1801 the advanced student received a temporary appointment as doctor for the poor a t Medevi, a spa and health resort. Here he analyzed the waters of the spring and constructed from 60 zinc plates and 60 copper coins a voltaic pile t o he used for healing purposes. These two tasks were to set the pattern for all his future research. The problems arising from them occupied him during all the rest of his life. The water analysis became his disputatio pro exern'tio, the description of a voltaic pile his disputatio pro gradu medico.(4) On the basis of the latter he was awarded his doctor's degree on May 1,1802. Although both papers
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owed their origin to pure chance, although they betrayed no correlation or definite plan of work, they decisively influenced his entire thinking. During his whole future life analytical investigations were to be his main activity, and the study of electrochemical reactions the basis of his theoretical ideas. After Berzelius had settled down in Stockholm as a wretchedly paid physician his galvanic studies brought him into contact with Vilhelm von Hisinger, a mine owner (1766-1852), who offered him several rooms for research. Here the two men began the task of "finding the laws according to which chemical reactions take place in a voltaic pile." Their common investigations were published in 1803 under the title "Experiments Dealing With Reactions of the Voltaic Pile on Salts and Some of Their Bases" (5). In this paper they enunciated ideas and showed results that did not become common scientific knowledge until sixteen years later through the publications of Hurnphry Davy (17781829). Vauquelin (1763-1829), President of the French Academy of Sciences, confirmed this fact on addressing
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Berzelius in 1819. He said: "We consider it our duty to inform you that we would have divided the first prize awarded by us to Humphry Davy between him and both of you, had we learned earlier about your and Mr. Hisinger's work on chemical reactions of the voltaic pile" (6). In order to improve his distressing financial situation he entered upon a road that all men devoted to pure science should avoid. He became involved in business transactions and soon fell a prey to uuscrupulousindividuals who stripped him of all his money, so that pale and emaciated he had to work as a common laborer for his daily bread. He wrote in his "Autobiography": "With a fixed yearly income of only 66 Reichstaler and 32 Schillings I found myself owing the bank a little more than 1000 Reichstaler. . . . For ten long years I had to pay the bank every penny that I could scrape together, deducting only the most necessary living expenses" (7). But thanks to his rugged constitution he survived all hardships. Unperturbed in spite of all calamities and with an iron will he remained faithful to science. Slowly he climbed to success. In 1806 he was appointed lecturer in chemistry a t Karlsberg University in Stockholm (at 100 Reichstaler annually), in 1807 He was made professor at the Chirurgical School a t Riddarholm, and on June 15, 1808, he was voted a member of the Academy. The first volume of his "Chemistry of Animals" appeared in 1806. It was, however, in reality a textbook on physiological chemistry and chemical physiology. Even forty years Jater, Friedrich Wohler, carried away by his admiration of this work, exclaimed: "I am astounded a t the abundance of facts and personal observations that the book contains. I am amazed a t the sccomplishments of the man in this field, particularly in view of the fact that these lectures were given as early as 1803-5" (8). The first volume of his famous "Textbook of Chemistry" came out in 1808. His work on this text forced Berzelius to study all details most discriminatingly. It paved the way for his life-task, i. e., "the attempt to find the definite and simple proportions according to which the constituent parts in inorganic matter are bound together" (9). We should not forget that in spite of Lavoisier's primarily quantitative way of thinking, even a man like Berzelius, in logically carrying out the ideas of the great Frenchman, highly underestimated the value of the quantitative relations made in his own time. In preparing the above-mentioned textbook Berzelius also came across two works, that of Jeremias Benjamin Richter (1762-1807) (lo), and that of Karl Friedrich Wenzel (1740-93) (11). It appeared to him "as clearly as the sun" that Wenzel's stoichiometric values and Richter's law of neutralization had to be natural laws, and he wrote: "This fact gave all my future research, i. e., the study of chemical proportions, its direction (16). The experiments that proved his theories went far beyond those of all his predecessors. Yet he freely gave credit by name to all of them, namely to Olof Torbern Bergman (1735-84), J. B. Richter, C. F. Wenzel, Joseph Louis Proust (1754-1826). He fully
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realized that "the scientific progress won by the law of definite proportions, as explained below, is only a trifle compared to that which will result from future iuvestigations." He saw that in its consequences it is one of the most far-reaching developments yet attained by science (IS). Next came the determination of atomic weights. Berzelius was a t first very dubious about Dalton's atomic theory, but after examining it he became one of its foremost supporters (14). He published his first table of atomic weights in 1814 a t Stockholm, and one year later it appeared in a German journal (15). When he edited it again, augmented and improved (16), it listed 46 elements and about 2000 compounds, all of which he himself had analyzed. In order to fully appreciate this accomplishment we should never lose sight of the unfavorable conditions under which he worked. His laboratory was poorly equipped; chemicals could not be purchased, and he was forced, therefore, to prepare his own. According to his own statement Berzelius repeated many an analysis twenty to thirty times before he trusted his own results. Quite different were the conditions in England, which he visited from June to November in the year 1812. He wrote in his "Autobiography": "I had no inkling of the fine equipment they had a t their command. The methods employed, however, to obtain precise results were far inferior to my own" (I7). During an extensive trip to France, Switzerland, and Germany (June, 181&September, 1819) he not only formed friendships with many scholars of his profession who exercised a stimulating influence upon him, but he was also fortunate enough to obtain instruments and chemicals through the generosity of Count Gustav Carl Friedrich Lowenhjelm (1771-1856), the Swedish ambassador in Paris. In Berlin he became acquainted with young Eilhard Mitscherlich (1794-1863). He recommended him to the Prussian Minister Karl von Stein zum Altenstein (1770-1840) as successor to Martin Heinrich Klaproth (1743-1817), professor of chemistry a t the University of Berlin. His recommendation wae based on Mitscherlich's epoch-making paper, "Concerning the relation of quantitative composition and crystalline form in arsenic salts and phosphates" (18). The Prussian minister desired, however, that Mitscherlich first accompany Berzelius to Stockholm as his pupil. The discovery of isomorphism by Mitscherlich and of atomic heat by Dulong and Petit (both in 1819) led Berzelius to a renewal of his investigations and calculations on atomic weights. On publishing a new chart of atomic weights in 1826 (19) he changed most of his previous numbers. To make them conform to the laws of Dulong and Petit, as well as those of Mitscherlich, he divided them by two or four, respectively. With his incredible accnracy in finding and applying proper analytical methods and with his admirable and delicate technique he determined atomic values that deviate but very little from those commonly used today ($0). As a basis of comparison Berzelius chose oxygen, which he
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considered the "cardinal point of chemistry." He rejected hydrogen as anjnsuitable basis, since it combines with only a few elements. In addition the low weight of hydrogen makes a precise analysis of hydrogen compounds extremely difficult (21). Lothar Meyer, who relied on accurate atomic weights for his periodic system of elements, expressed the following opinion of Berzelius: "In choosing stoichiometrical quantities to he set up as atomic weights he used all the auxiliary means a t his disposal, such as analogy in chemical behavior, density in a gaseous state, isomorphism, and specific heat, to be sure, none of these with absolute consistency, but with such delicacy of perception that with but few exceptions (alkalai metals, silver, boron, silicon, and some rare elements) our currently accepted atomic weights are essentially still those of Berzelius, even though for a considerable time other hypotheses sought tosupplant that of Berzelius" (22). Proust's hypothesis that atomic weights were integral multiples of the atomic weight of hydrogen was rejected by Rerzelius, primarily on account of an alleged proof that Thomson brought forth. "The results of his (Thomson's) experiments agree with Proust's hypothesis down to the'last decimal point. But when one remembers how unreliable Thomson's results were when he could not calculate them beforehand, he realizes the value of any proof based upon the accuracy with which he carried out his experiments" (23). To a man like Berzelius, whose natural tendency was to think logically, the confusing and unorganized mass of facts concerning quantitative relations was highly unsatisfactory, just as one would find a pile of stones lacking the value of the simplest house. Berzelius reduced this confusion into a unified electrochemical system. Although after his death his system was abandoned, owing to its inability in its original form to interpret substitutions in organic chemistry, its basic ideas lived on. After elimination of all disturbing features and through later knowledge of atomic structure his ideas have come to life again in the twentieth century. Berzelius proceeded from the conviction that every chemical process was a t the same time an electrical one. Every smallest particle, according to the nature of the substance involved, was supposed to he either positively or negatively charged, although in varying degrees. In the forming of compounds these electrical charges neutralized each other. Based on this ionization, Berzelius believed that he was able to recognize the electrical nature of every single constituent. He inferred that whatever became attracted by the negative pole (hydrogen and metals) had to be positive (84). In accordance with the varying charges of the elements he arranged them in a series which began with the absolutely negative oxygen. The series led, with thegradual decrease of negative charges and increase of positive ones, to the metals, of which the alkalies seemed to be the most strongly positive. Every member of the long series, with hydrogen approximately in the center, was negative in reference to the preceding one and positive in relation to the following one. The
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oxides of the first half formed strong acids, those of the second half bases. Compounds formed by the union of oxides of acidic nature with those of basic characteristics produced salts. In a similar fashion Berzelius likewise grouped other compounds into classes: (1) electronegative (acids), (2) electropasitive (bases), and (3) neutral. Parallel with the development of his electrochemical dual system Berzelius also devoted himself to inventing a suitable nomenclature. Most of the traditional names for chemical substances owed their origin to accident, as, for example, sal mirabile Glauberi (sodium sulfate), or sal pdychrestum Glaseri (potassium sulfate). Many of these names apparently united substances that in reality had no relation to each other, such as spiritus uini (ethyl alcohol), spiritus salis (hydrogen chloride), spiritusfumans Libauii (stannic chloride), spiritus cornu cerui (ammonium carbonate). As early as 1787 Lavoisier, together with Guyton de M o N ~ ~ Fourcroy, u, and Berthelot proposed a chemical nomenclature that suited his antiphlogistic system. Berzelius improved the latter and adapted it to his dualistic system (25). At the same time he chose new and more appropriately modiEed ndmes for some elements, e. g., magnesium instead of magnium or talcium to avoid a confusion with manganinm (manganese) or calcium; furthermore, beryllium instead of glycinium, natrium instead of sodium (retained in English), stibium instead of antimonium, cerium instead of cercerium, tantalium instead of columbium, and wolframium instead of scheelium. Since these names in themselves, in spite of their b e ing so practical, failed to indicate the quantitative proportions of their constituent parts without additional information about their percentage, Berzelius ingeniously created a language of signs which was to be quantitative throughout, and which was no longer concerned with the old chemical symbols as mere labels. For this chemical shorthand he did not choose geometrical figures such as had:been employed previously, but letters, to which he assigned a quantitative value (26). The choosing of letters dates back perhaps to J. B. Richter, who in addition to the symbols used in his day for the newly discovered elements (chromium, titanium, and tellurium) employed the letters xp, Ti, and Te (27). Richter's letter-symbols were, however, only qualitative in nature. For Berzelius, on the other hand, the quantitative was the prime concern in the expression of chemical proportions. He wrote: "Permit me to remark that the purpose of these new symbols is not, as with the older ones, to serve as mere labele for bottles in laboratories. Their sole purpose is to facilitate the expression of combining proportions, and without undue verbosity to indicate the proportionate number of molecules in any given compound. In determining molecular weights ihese formulas will enable us to express summary results of any analysis that are as simple and easy to remember as the algebraic formulas used in mechanics. A chemical symbol always stands for one volume (i. e., molecule according to Richter, and atom according to Dalton) of a substance. If it is nec-
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essary to indicate more than one volume (i. e., molecule), the respective number of molecules involved is added" (28). No brain could possibly retain the percentage compositions of a large number of compounds, whereas it is comparatively easy to commit to memory the few atomic weights'and the most important formulas. We are then a t all times in a position to calculate percentage compositions. The style of writing is in accord with our present changed views and increased demands for clarity and precision of meaning, hut the essence of the symbolical expression has remained as it came from the hand of Berzelius. . Berzelius performed a similar service for mineralogy as he had for chemistry. His system, making a science which defines out of one which merely describes, replaced the earlier systems of Hany, Werner, Xarsten, and Hausmann. In 1811 Gehlen was hoping for a reform that only a chemical system could accomplish. He says: "But I did not realize that this reform wasso near, that Berzelius, through his investigations, had already brought it about" (29). In Sweden, a country rich in iron ore, chemico-mineralogical studies had always evoked great interest, particularly since Karl X I had founded a technical laboratory (1686), entrusting it with the task of examining minerals, ores, and various soils. Berzelius' studies in this field received a new impetus through the present of William MacMichael, an English physician, who gave Berzelius a valuable collection of minerals in return for practical instruction in chemistry. Abraham Gottlob Werner's (1749-1817) (30) classification of minerals according to external characteristics did not satisfy Berzelius' critical mind. Such an arrangement sufficedperhaps for a layman collecting minerals as a hobby. But orderly scientific thinking looked for the inner reasons for their homogeneity, and these could lie only in their chemical composition. Just as, since the mast ancient times, the miner and the metallurgist were mainly interested in the metal extracted from the ore, so Berzelius, with his keen penetration, clearly recognized that the substance itself was the decisive factor in all minerals, and that the same laws were valid in both the mineral kingdom and in chemistry. His "attempt to found a purely scientific system in mineralogy by applying the electrochemical theory and the laws of chemical proportions" (31) will remain a memorable intellectual feat for all times. At first Berzelius arranged h;s classification according to electropositive constituents, i. e . , metals, since these are the most characteristic and basic substances of mining. After Mitscherlich had proved isomorphous substitution in minerals, i. e., substitution of one chemical component in a mineral by another without affecting its manner of crystallization, and when it became more and more apparent that such substitutions rarely affected the acid radical but frequently the metal, Berzelius changed his system of classification according to electronegative constituents, aa is still the case today (32). Berzelius' mineralogical investigations led him to a study of the outer space. He examined meteorites (55)
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Be.ze1iu. a . a Young Man
and logically concluded that they could not be of earthly origin, and that they gave us a hint of the chemical composition of other heavenly bodies (54). For his analysis of minerals Berzelius employed the blowpipe, the use of which he learned from Johann Gottlieb Gahn (1745-1818). In the handling of it Berzelius became a veritable master. Through both his writings and his lectures he made the blowpipe an indispensable tool (55). During one of his repeated trips to Germany he also instructed Goethe (in Eger, 1822) in its use, to the great delight of the latter (56). During the course of his many analyses Berzelius discovered selenium in the chamber sludge a t the sulfuric acid plant in Gripsholm (57), and after wearisome and difficult experiments also thorium (58). In addition Berzelius was the first to succeed in preparing the following elements that had already been known hut not .yet isolated: silicon, titanium, tantalium, and zirconium. On publishing his results Berzelius categorically emphasized the fact that silicon is acid-forming and that it gives rise to many silicic acids. Through his gift for creating a concise framework in t h e form of new and fruitful chemical conceptions for apparently divergent and contradictory ideas, he served the progress of science in a manner that can hardly be sufficiently appreciated-all this quite apart from the astonishing number of experiments he conducted. Thus he related his discovery of "racemic acid having not only the same atomic weight but also the same percentage and atomic composition as tartaric acid" (59) to his previous endings of two isomorphous stannic acids. Furthermore he brought these into relationship with the resuks of Liehig and Wohler who had found the same values for silver fulminate and silver cyanate. In addition, he related this discovery to that of Faraday that ethylene and butylene have the same percentaxe
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composition but a different vapor density, and finally to Wohler's conversion of ammonium cyanate into urea. For these facts, up till then isolated, he coined the collective term "isomorphism." He later differentiated between genuine isomorphism, or metamerism, and polymerism as follows: "Substances are isomorphous when they possess different properties although their chemical composition and molecular weight are alike," whereby it is assumed "that an equal number of the same elements are joined in a different manner," while in the case of polymerism the substances "have different molecular weights, mostly multiples of each other, but the same percentage composition" (40). During the course of his research on tartaric and racemic acids Berzelius also paved the way for the term "allotropy" by posing the following question: "Is there also for elements a similar isomorphous condition as for compounds?" As examples he cited "the allotropic modification of carbon in diamonds and graphite and the modifications of platinum that, when obtained in the 'wet' process through the reduction of platinum salts by means of alcohol, differ from those resulting from bringing ammonium chloroplatinate to a glow" (41). Soon he became convinced of the necessity of a name for this phenomenon, and he chose for it the word "allotropy" (@). He also mentioned incidentally that red phosphorus, a t that time considered a lower oxide, was nothing but an allotropic modification of yellow phosphorus. He wrote: "Phosphorus has several modifications of which the following are characteristic: (1) phosphorus in its usual form . . ., (2) a red modification which is produced by the action of the sun, even in the vacuum of a barometer. Red phosphorus does not combine with oxygen, and returns to its original form upon distillation" (45). Mitscherlich's paper, "On the Formation of Ether" (U),led Berzelius to the idea of "catalysis" (46). He included in his conception of catalysis substances which initiate chemical reactions, regulating their speed as well as their course of action, without themselves being noticeably used up. His prophetic eye recognized the value and necessity of studying such catalysts and led him to the assumption "that thousands of catalytic processes take place between tissues and fluids in living plants and animals." During his lifetime "catalysis" was bitterly attacked, but in the twentieth century the term became immeasurably fruitful in both the technological and biological fields (46). Through his teachmgs and his keenly critical judgments Berzelius, the fluent writer, has greatly furthered the progress not only of chemistry, but also of other sciences. His textbooks are models of crystal-like clarity and easy comprehension: They conform to the principle: "He who writes a scientific paper should spare himself no effort to be as clear and intelligible as possible for the sake of those who are to read and understand it" (47). In his Annual Reports he presented with enviable clearsightedness and an incormptible love of truth the vital and ~romisingideas that he detected in all the luxnriant, widespreading outgrowths of a newly
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developing science. He formulated his ideas so clearly that every intelligent person could grasp them. His life was work. In the words of the psalmist as well as his own it was "a precious one." Social intercourse bad no attraction to him, who said: "Without hard work I should soon have found myself completely isolated, since most of my friends had scattered in all directions. Besides, I now feel more than ever before that an active scholar should never count on being or becoming a person who either gives or finds pleasure in social entertainment" (48). His motto on the medal issued by the Congress of Natural Scientists in Berlin (1828) reads as follows: Pondera et Numeros, whereby iwestigavit should be added. Berzelius died in the early morning hours of August 7, 1848, after a long illness under which he had suffered during the last years of his life. While his body was returned to the earth from which it came, his spirit will always remain alive and be active as long as mankind is engaged in the pursuit of chemical science. LITERATURE CITED (1) BUG,, G~~NTHER, " B U C ~der Grossen Chemikek," VOI. I, 1929, pp. 428-49. (2) SODERBAUM, HENRIK GUSTAV,llJac.~erzeliusLevnadsteckning," published by the Royal Swedish Academy of Science, 3 vols., Alqvist & Wiksells Boktryckeri A. B., U p psala, 1929, 1929, 1931. The widely scattered material was collected by Arne Holmberg in: "Bihliografi ofver J. J. Borzelius," published by The Royal Swedish Academy of Science, Parts 1-3, Stockholm and Uppsala, 1933-1936. (3) C f , SaDERBAuM, H, G,, uLevnadsteckning,n Val. p. 105. Berdius wrote a "Biografi Ofver Johan Afielius, Kemie professor vid Universitetet Uppsda, riddare of kongl. Wasaorden," in K. V.A . Handlingar, 263-6 (1837). (4) "De electricitatis Galvanicae appartratu cel. Volta excitae in corpora organic* effectu," Uppsala, 1802. "Afhandling om Galvanismus," Stockholm, 1802. (5) Fir& printing in German in GEHLER'S N m e ~Journal d w Chemie, 1, 115-49 (1803); second printing in Swedish, "Elektriska Stapelns Theari"; third printing in GILBERT'SAnnalen, 27,269 (1807). J . J., riSelbsthiographi~cheAufzeichnungen," (6) BERZELIUS, published on behalf of the Royal Swedish Academy of Science by H. G. S~DERBAUM. Translated into German by EMILIEWOHLER and revised by GEORGW. A. K A H ~ RAUM, in Leipzig, 1903, p. 29. (7) Ibid., p. 41. Letter to Liebig, Gottingeh, April 1847, C f , wechsel Liehig-Wohler," ed. by AUG. WILE.HOFMANN, 2 vols., Braunschweig, 1888; Vol. 1, p. 295. (9) GILBERT'S Annalen der Physik, 37, 249-334, 415-72 (1811); 38, 161-226 (1811); 40, 162-208, 235-330 (1812). SCAWEIGGER'S J o u m l fii7 Chemie und Physik, 1,257-62 (1811); 2, 297-326 (1811); summarized in K. V. A. Handlingar, 169-97 (1811). "Om do hestitmda proportimer kvari don organiska naturens hestandsdelar finnas formade; summasiskt resultat xf de forsok slim haldfver blifvit anstiil1de."-Wilh. Ostwald's Klas~ikerder exakten Wissenschaften, No. 35. (lo) R I C ~ T E R J., B., u~nfmgsgr"nde der stiiehiometrie Messkunst chemiseher Elemente; Ueber die neueren ' Gegenstitndeder Chemie," 11 Stiieke. (11) WENZEL, C. F.,"Lehre von der Verwandsohsft der Korper," 1777. (12) BERZELIUS, J. J., "Selbstbiographiscbe Aufseiohnungen," p. 46.
