J ~ N S JAKOB BERZELIUS

RUDOLF WINDERLICH Oldenburg i./O., Germany (Translated by J. M i c h a e l Moore, Muhlenberg 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-country- man, H. G. Soderbaum, in Brugge's "Book of Great Chemists" discussed only Berzelius' law of definite pro- portions 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 dif- ficulty 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 hoy- hood. 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 lahora- tory 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 ana- lyzed the waters of the spring and constructed from 60 zinc plates and 60 copper coins a voltaic pile to 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

J. J. BERZELIUS

owed their origin to pure chance, although they be- trayed no correlation or definite plan of work, they de- cisively influenced his entire thinking. During his whole future life analytical investigations were to be his main activity, and the study of electrochemical re- actions 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 enunci- ated ideas and showed results that did not become com- mon scientific knowledge until sixteen years later through the publications of Hurnphry Davy (1778- 1829). 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 uuscrupulousindivid- uals 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 Stock- holm (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 Acad- emy. 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 as- tounded a t the abundance of facts and personal ob- servations 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 Chemis- try" 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 fu- ture 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

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 iuvesti- gations." He saw that in its consequences it is one of the most far-reaching developments yet attained by sci- ence (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 ap- preciate 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 pre- pare 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" (I 7).

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 am- bassador in Paris. In Berlin he became acquainted with young Eilhard Mitscherlich (1794-1863). He recom- mended 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, "Con- cerning the relation of quantitative composition and crystalline form in arsenic salts and phosphates" (18). The Prussian minister desired, however, that Mitscher- lich first accompany Berzelius to Stockholm as his pu- pil.

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 calcula- tions on atomic weights. On publishing a new chart of atomic weights in 1826 (19) he changed most of his pre- vious 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 in- credible accnracy in finding and applying proper analyti- cal 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

502 JOURNAL OF CHEMICAL EDUCATION

considered the "cardinal point of chemistry." He re- oxides of the first half formed strong acids, those of the jected hydrogen as anjnsuitable basis, since it combines second half bases. Compounds formed by the union of with only a few elements. In addition the low weight oxides of acidic nature with those of basic characteristics of hydrogen makes a precise analysis of hydrogen com- produced salts. In a similar fashion Berzelius likewise pounds extremely difficult (21). Lothar Meyer, who grouped other compounds into classes: (1) electro- relied on accurate atomic weights for his periodic sys- negative (acids), (2) electropasitive (bases), and (3) tem of elements, expressed the following opinion of neutral. Berzelius: "In choosing stoichiometrical quantities to Parallel with the development of his electrochemical he set up as atomic weights he used all the auxiliary dual system Berzelius also devoted himself to inventing means a t his disposal, such as analogy in chemical be- a suitable nomenclature. Most of the traditional names havior, density in a gaseous state, isomorphism, and for chemical substances owed their origin to accident, specific heat, to be sure, none of these with absolute con- as, for example, sal mirabile Glauberi (sodium sulfate), sistency, but with such delicacy of perception that with or sal pdychrestum Glaseri (potassium sulfate). Many but few exceptions (alkalai metals, silver, boron, silicon, of these names apparently united substances that in and some rare elements) our currently accepted atomic reality had no relation to each other, such as spiritus weights are essentially still those of Berzelius, even uini (ethyl alcohol), spiritus salis (hydrogen chloride), though for a considerable time other hypotheses sought spiritusfumans Libauii (stannic chloride), spiritus cornu tosupplant that of Berzelius" (22). Proust's hypothesis cerui (ammonium carbonate). As early as 1787 La- that atomic weights were integral multiples of the voisier, together with Guyton de M o N ~ ~ u , Fourcroy, atomic weight of hydrogen was rejected by Rerzelius, and Berthelot proposed a chemical nomenclature that primarily on account of an alleged proof that Thomson suited his antiphlogistic system. Berzelius improved brought forth. "The results of his (Thomson's) experi- the latter and adapted it to his dualistic system (25). ments agree with Proust's hypothesis down to the'last At the same time he chose new and more appropriately decimal point. But when one remembers how unreli- modiEed ndmes for some elements, e. g., magnesium in- able Thomson's results were when he could not calcu- stead of magnium or talcium to avoid a confusion with late them beforehand, he realizes the value of any proof manganinm (manganese) or calcium; furthermore, based upon the accuracy with which he carried out his beryllium instead of glycinium, natrium instead of so- experiments" (23). dium (retained in English), stibium instead of antimo-

To a man like Berzelius, whose natural tendency nium, cerium instead of cercerium, tantalium instead of was to think logically, the confusing and unorganized columbium, and wolframium instead of scheelium. mass of facts concerning quantitative relations was Since these names in themselves, in spite of their b e highly unsatisfactory, just as one would find a pile of ing so practical, failed to indicate the quantitative pro- stones lacking the value of the simplest house. Ber- portions of their constituent parts without additional zelius reduced this confusion into a unified electrochemi- information about their percentage, Berzelius ingeni- cal system. Although after his death his system was ously created a language of signs which was to be quan- abandoned, owing to its inability in its original form to titative throughout, and which was no longer concerned interpret substitutions in organic chemistry, its basic with the old chemical symbols as mere labels. For this ideas lived on. After elimination of all disturbing fea- chemical shorthand he did not choose geometrical tures and through later knowledge of atomic structure figures such as had:been employed previously, but let- his ideas have come to life again in the twentieth cen- ters, to which he assigned a quantitative value (26). tury. Berzelius proceeded from the conviction that The choosing of letters dates back perhaps to J. B. Rich- every chemical process was a t the same time an elec- ter, who in addition to the symbols used in his day for trical one. Every smallest particle, according to the na- the newly discovered elements (chromium, titanium, ture of the substance involved, was supposed to he either and tellurium) employed the letters xp, Ti, and Te (27). positively or negatively charged, although in varying Richter's letter-symbols were, however, only qualita- degrees. In the forming of compounds these electrical tive in nature. For Berzelius, on the other hand, the charges neutralized each other. Based on this ioniza- quantitative was the prime concern in the expression of tion, Berzelius believed that he was able to recognize chemical proportions. He wrote: "Permit me to re- the electrical nature of every single constituent. He mark that the purpose of these new symbols is not, as inferred that whatever became attracted by the with the older ones, to serve as mere labele for bot- negative pole (hydrogen and metals) had to be posi- tles in laboratories. Their sole purpose is to facilitate tive (84). In accordance with the varying charges of the expression of combining proportions, and without the elements he arranged them in a series which began undue verbosity to indicate the proportionate number with the absolutely negative oxygen. The series led, of molecules in any given compound. In determining with thegradual decrease of negative charges and in- molecular weights ihese formulas will enable us to ex- crease of positive ones, to the metals, of which the al- press summary results of any analysis that are as sim- kalies seemed to be the most strongly positive. Every ple and easy to remember as the algebraic formulas member of the long series, with hydrogen approximately used in mechanics. A chemical symbol always stands in the center, was negative in reference to the preceding for one volume (i. e., molecule according to Richter, and one and positive in relation to the following one. The atom according to Dalton) of a substance. If it is nec-

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essary to indicate more than one volume (i. e., mole- cule), the respective number of molecules involved is added" (28). No brain could possibly retain the per- centage compositions of a large number of compounds, whereas it is comparatively easy to commit to memory the few atomic weights'and the most important formu- las. 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, re- placed the earlier systems of Hany, Werner, Xarsten, and Hausmann. In 1811 Gehlen was hoping for a re- form 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 al- ready brought it about" (29). In Sweden, a country rich in iron ore, chemico-mineralogical studies had al- ways evoked great interest, particularly since Karl X I

Be.ze1iu. a. a Young Man

had founded a technical laboratory (1686), entrusting it with the task of examining minerals, ores, and various and logically concluded that they could not be of earthly soils. Berzelius' studies in this field received a new im- origin, and that they gave us a hint of the chemical petus through the present of William MacMichael, an composition of other heavenly bodies (54). English physician, who gave Berzelius a valuable col- For his analysis of minerals Berzelius employed the lection of minerals in return for practical instruction in blowpipe, the use of which he learned from Johann chemistry. Abraham Gottlob Werner's (1749-1817) Gottlieb Gahn (1745-1818). In the handling of it Ber- (30) classification of minerals according to external zelius became a veritable master. Through both his characteristics did not satisfy Berzelius' critical mind. writings and his lectures he made the blowpipe an indis- Such an arrangement sufficed perhaps for a layman col- pensable tool (55). During one of his repeated trips to lecting minerals as a hobby. But orderly scientific Germany he also instructed Goethe (in Eger, 1822) in its thinking looked for the inner reasons for their homoge- use, to the great delight of the latter (56). neity, and these could lie only in their chemical composi- During the course of his many analyses Berzelius dis- tion. Just as, since the mast ancient times, the miner covered selenium in the chamber sludge a t the sulfuric and the metallurgist were mainly interested in the metal acid plant in Gripsholm (57), and after wearisome and extracted from the ore, so Berzelius, with his keen pene- difficult experiments also thorium (58). In addition tration, clearly recognized that the substance itself was Berzelius was the first to succeed in preparing the fol- the decisive factor in all minerals, and that the same lowing elements that had already been known hut not laws were valid in both the mineral kingdom and in .yet isolated: silicon, titanium, tantalium, and zirco- chemistry. His "attempt to found a purely scientific nium. On publishing his results Berzelius categorically system in mineralogy by applying the electrochemical emphasized the fact that silicon is acid-forming and theory and the laws of chemical proportions" (31) will that it gives rise to many silicic acids. remain a memorable intellectual feat for all times. At Through his gift for creating a concise framework in first Berzelius arranged h;s classification according to t h e form of new and fruitful chemical conceptions for electropositive constituents, i. e . , metals, since these apparently divergent and contradictory ideas, he served are the most characteristic and basic substances of min- the progress of science in a manner that can hardly be ing. After Mitscherlich had proved isomorphous sub- sufficiently appreciated-all this quite apart from the stitution in minerals, i. e., substitution of one chemical astonishing number of experiments he conducted. Thus component in a mineral by another without affecting he related his discovery of "racemic acid having not its manner of crystallization, and when it became more only the same atomic weight but also the same percent- and more apparent that such substitutions rarely af- age and atomic composition as tartaric acid" (59) to fected the acid radical but frequently the metal, Ber- his previous endings of two isomorphous stannic acids. zelius changed his system of classification according to Furthermore he brought these into relationship with electronegative constituents, aa is still the case today the resuks of Liehig and Wohler who had found the (32). same values for silver fulminate and silver cyanate. In

Berzelius' mineralogical investigations led him to a addition, he related this discovery to that of Faraday study of the outer space. He examined meteorites (55) that ethylene and butylene have the same percentaxe

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composition but a different vapor density, and finally developing science. He formulated his ideas so clearly to Wohler's conversion of ammonium cyanate into urea. that every intelligent person could grasp them. For these facts, up till then isolated, he coined the col- His life was work. In the words of the psalmist as lective term "isomorphism." He later differentiated well as his own it was "a precious one." Social inter- between genuine isomorphism, or metamerism, and course bad no attraction to him, who said: "Without polymerism as follows: "Substances are isomorphous hard work I should soon have found myself completely when they possess different properties although their isolated, since most of my friends had scattered in all chemical composition and molecular weight are alike," . directions. Besides, I now feel more than ever before whereby it is assumed "that an equal number of the that an active scholar should never count on being or same elements are joined in a different manner," while becoming a person who either gives or finds pleasure in in the case of polymerism the substances "have differ- social entertainment" (48). His motto on the medal ent molecular weights, mostly multiples of each other, issued by the Congress of Natural Scientists in Berlin but the same percentage composition" (40). (1828) reads as follows: Pondera et Numeros, whereby

During the course of his research on tartaric and race- iwestigavit should be added. mic acids Berzelius also paved the way for the term Berzelius died in the early morning hours of August "allotropy" by posing the following question: "Is 7, 1848, after a long illness under which he had suffered there also for elements a similar isomorphous condition during the last years of his life. While his body was re- as for compounds?" As examples he cited "the allo- turned to the earth from which it came, his spirit will tropic modification of carbon in diamonds and graphite always remain alive and be active as long as mankind is and the modifications of platinum that, when obtained engaged in the pursuit of chemical science. in the 'wet' process through the reduction of platinum salts by means of alcohol, differ from those resulting LITERATURE CITED from bringing ammonium chloroplatinate to a glow" (1) BUG,, G~~NTHER, " B U C ~ der Grossen Chemikek," VOI. I, (41). Soon he became convinced of the necessity of a 1929, pp. 428-49. name for this phenomenon, and he chose for it the word (2) SODERBAUM, HENRIK GUSTAV, llJac. ~erzelius Levnadsteck- "allotropy" (@). He also mentioned incidentally that ning," published by the Royal Swedish Academy of Sci-

ence, 3 vols., Alqvist & Wiksells Boktryckeri A. B., U p red phosphorus, a t that time considered a lower oxide, psala, 1929, 1929, 1931. The widely scattered material was nothing but an allotropic modification of yellow was collected by Arne Holmberg in: "Bihliografi ofver phosphorus. He wrote: "Phosphorus has several modi- J. J. Borzelius," published by The Royal Swedish Acad- fications of which the following are characteristic: (1) emy of Science, Parts 1-3, Stockholm and Uppsala,

1933-1936. phosphorus in its usual form . . ., (2) a red modification (3) Cf , SaDERBAuM, H, G,, uLevnadsteckning,n Val. p. 105. which is produced by the action of the sun, even in the Berdius wrote a "Biografi Ofver Johan Afielius, Kemie vacuum of a barometer. Red phosphorus does not com- professor vid Universitetet Uppsda, riddare of kongl. bine with oxygen, and returns to its original form upon Wasaorden," in K. V. A. Handlingar, 263-6 (1837). distillation" (45). (4) "De electricitatis Galvanicae appartratu cel. Volta excitae in

Mitscherlich's paper, "On the Formation of Ether" corpora organic* effectu," Uppsala, 1802. "Afhandling om Galvanismus," Stockholm, 1802.

(U), led Berzelius to the idea of "catalysis" (46). He (5) Fir& printing in German in GEHLER'S N m e ~ Journal dw included in his conception of catalysis substances which Chemie, 1, 115-49 (1803); second printing in Swedish, initiate chemical reactions, regulating their speed as "Elektriska Stapelns Theari"; third printing in GIL-

well as their course of action, without themselves being BERT'S Annalen, 27,269 (1807). (6) BERZELIUS, J . J., riSelbsthiographi~che Aufzeichnungen,"

noticeably used up. His prophetic eye recognized the published on behalf of the Royal Swedish Academy of value and necessity of studying such catalysts and led Science by H. G. S~DERBAUM. Translated into German him to the assumption "that thousands of catalytic by EMILIE WOHLER and revised by GEORG W. A. K A H ~ processes take place between tissues and fluids in living RAUM, in Leipzig, 1903, p. 29.

(7) Ibid., p. 41. plants and animals." During his lifetime "catalysis" Letter to Liebig, Gottingeh, April 1847, Cf , was bitterly attacked, but in the twentieth century the wechsel Liehig-Wohler," ed. by AUG. WILE. HOFMANN, term became immeasurably fruitful in both the tech- 2 vols., Braunschweig, 1888; Vol. 1, p. 295. nological and biological fields (46). (9) GILBERT'S Annalen der Physik, 37, 249-334, 415-72 (1811);

Through his teachmgs and his keenly critical judg- 38, 161-226 (1811); 40, 162-208, 235-330 (1812). SCAWEIGGER'S J o u m l fii7 Chemie und Physik, 1,257-62

ments Berzelius, the fluent writer, has greatly furthered (1811); 2, 297-326 (1811); summarized in K. V. A. the progress not only of chemistry, but also of other sci- Handlingar, 169-97 (1811). "Om do hestitmda propor- ences. His textbooks are models of crystal-like clarity timer kvari don organiska naturens hestandsdelar finnas and easy comprehension: They conform to the princi- formade; summasiskt resultat xf de forsok slim haldfver

blifvit anstiil1de."-Wilh. Ostwald's Klas~iker der exak- ple: "He who writes a scientific paper should spare ten Wissenschaften, No. 35. himself no effort to be as clear and intelligible as pos- (lo) RIC~TER, J. B., u~nfmgsgr"nde der stiiehiometrie sible for the sake of those who are to read and under- Messkunst chemiseher Elemente; Ueber die neueren stand it" (47). In his Annual Reports he presented with ' Gegenstitndeder Chemie," 11 Stiieke.

enviable clearsightedness and an incormptible love of (11) WENZEL, C. F., "Lehre von der Verwandsohsft der Korper," 1777.

truth the vital and ~romising ideas that he detected in (12) BERZELIUS, J. J., "Selbstbiographiscbe Aufseiohnungen," all the luxnriant, widespreading outgrowths of a newly p. 46.