Popular Science Monthly/Volume 9/May 1876/Character and Work of Liebig

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JUSTUS LIEBIG was born on the 12th of May, 1803, at Darmstadt, in the grand-duchy of Hesse. His father was what in this country (England) we should term a wholesale druggist and dry-salter, a trade which is in Germany designated by the name of materialist. There is no doubt that the opportunities which he had of collecting chemical reagents, and of witnessing the preparation of many products which were the objects of his father's trade, early excited in him that curiosity which soon became an insatiable thirst. It is related on creditable testimony that at the age of fourteen years he had performed all the experiments of which he could get knowledge from books, or for which within his means he could obtain the materials, and it is related by himself that about that time there was not a work in the library of the Grand-duke of Darmstadt on chemistry which he had not read. Looking at his early days by the light of that information, we cannot doubt that the anecdote ordinarily told of his having been a dull boy is a mere mistake. He was abstracted by other pursuits, and there-fore, no doubt, neglected his school-work, but that he should have been less gifted than others cannot, under the circumstances, be believed. It is related by a credible person that in 1817, when he and his school-fellows were speaking to each other as to what pursuit they were to select, he said that he was going to be a chemist, whereupon the other boys laughed at him and told him he was a great fool, for a chemist was nothing. However, times have changed, and what at that time was considered as no pursuit is now an honored profession. In the year 1818 he gave a distinct direction to that early bent of his mind, and he followed almost the only way which at that time existed in Germany for studying chemistry; he became an apprentice in an ordinary apothecary's establishment. An apothecary in Germany is a more scientific person than perhaps many would believe. He has had a thorough training, he has passed examinations, and he represents, therefore, the scientific side of chemistry, pharmacy, and the science of drugs in perfection. To such an apothecary, residing at Heppenheim, near Darmstadt, Liebig went, and remained there about ten months, but in that occupation as an apprentice his mind soon became wearied, he saw that he could not attain his object; and when, while continuing some of his early experiments on the fulminates, on one occasion he had the misfortune to produce a great explosion, this fact quickly terminated his apprenticeship, and he returned to Darmstadt. These explosions in the early days of great chemists are not uncommon. It is related in the case of Scheele that, when he was apprenticed to an apothecary, he once had a great explosion, in consequence of which his landlady expelled him from the house.

Liebig returned to his father's house in the year 1814, and read for six months in order to prepare himself for visiting the University of Bonn. He there listened to the lectures on theoretical chemistry of the well-known Prof. Kastner, and he also studied the other natural sciences and some languages, and, what is very characteristic of his great genius and perseverance, he formed a society among the students for the purpose of teaching one another, and for discussing subjects connected with chemistry and physics. Kastner being called to Erlangen, Liebig followed him there, and we are told that there he read all the new chemical publications, established another students' society for the same object as the first, and made many friends among the students, of whom several continued that friendship up to their death. Thus the celebrated poet, Count Platen, corresponded with him to the time of his death in 1830, and of this friendship we can see many congenial influences in the writings of Liebig, for there is no doubt that, in his "Familiar Letters on Chemistry," the language, although always prose, frequently rises to the highest beauty, such as can only be produced by a mind of a poetical turn. The same influence of the classical period of German literature you will also perceive for example in the writings of Humboldt, particularly in his "Views on Nature," which are therefore considered as examples of classical German diction. Liebig also made the acquaintance of Bischof, the botanist, and of Engelhard, later Professor of Chemistry at Nuremberg. He went in for the severe study of what at that time was called philosophy, that is, he listened to the lectures on metaphysics and philosophy in general, of the then great Schelling. Now, let me give you the words of Liebig on that period of his life. He says: "I myself studied for some time in a university where the greatest philosophers and metaphysicians of the century carried the studying youths away to admiration and imitation. Who could at that time resist the infection? I, too, have lived and participated in this period so rich in words and ideas, so poor in true knowledge and solid studies: it has robbed me of two precious years of my life. I cannot describe the terror and dismay which I felt when I awoke from this giddy dream to consciousness. How many most gifted and talented men have I seen perish in this vertigo, how many wails about life-objects completely missed have I been obliged to hear afterward!" Thus he spoke in his work on the study of the natural sciences, which was published at Brunswick in 1840.

Now, in order that you may be able to apprehend what this kind of philosophy was, and to understand more fully the position from which he had to emancipate himself, even at that early time of his life, I will quote to you a very few passages, and I will make them as short as possible, compatible with illustration, from one of Schelling's works, from the periodical for speculative physics—mark the term, "Speculative Physics." I will quote the following passage: "Nature strives in the dynamical sphere necessarily to absolute indifference, not by magnetism nor by electricity is represented the totality of the dynamical process, but only by the chemical process. With the third dimension of the product the two other dimensions are opposed. In Nature itself there is one and inseparate, what is separated for the purpose of speculation." That is almost enough, but I will give you another passage which will be more striking because of the contrary itself being known to you. Here he says of the composition of water: "Water contains just the same as iron, but in absolute indifference as yonder in relative indifference, carbon and nitrogen, and thus all true polarity of the earth is reduced to an original south and north which are fixed in the magnet." Now, in order that you may believe that he did not merely speak of an admixture or impurity of carbon or nitrogen, but that he meant to say that it was the essence of water, and that it was really composed of these two elements, and not of any other, he goes on to say: "The animal is in organic Nature the iron; the plant is the water, for Nature begins with the relative separation of the sexes, and then ends in this separation. The animal decomposes the iron, the plant decomposes the water. The female and the male sex of the plant is the carbon and the nitrogen of the water." These are two examples of the philosophy of Schelling, which was believed at that time to be the science by which Germany could be regenerated, by which the generation which had then only just recovered its independence would be put on a firm mental basis. The followers of this system were called to the court of Prussia, and there Hegel, the philosopher, continued in a similar manner to teach doctrines which nowadays seem to be but a farrago of nonsense. Hegel says, for example, on the chemical process: "If electricity was the broken magnetism, because the opposite poles are independent bodies upon which the positive and negative electricity is distributed, and if the point of indifference is the explosion of an indifferent light by itself, then is the chemical process, on the other hand, the totality of the shaping. We have two independent bodies which belong more to the one or the other extreme; to the metal on the one hand, or the sulphur on the other, which meet in an indifferent medium, and by abandoning their abstract one-sidedness in which they decompose the medium combine to a third body which is the totality and the neutrality of the opposites, the dynamical process in its highest perfection."

When a young man of seventeen or eighteen years of age is capable of freeing himself from the trammels of such a chimera termed philosophy, which had taken such a deep hold of a whole nation as to cause to flock to the university where it was taught the selected youth of the whole country, you may give him credit for great power of mind and for great independence of judgment. Do not forget that this development of the philosophy of Schelling and Hegel was a consequence of the latter part of the philosophy of Kant. Kant's philosophy was great as long as it was based on the exact sciences, upon physics, and upon mathematics, but when he left that basis and went into the speculative philosophy he gradually went away from that basis which had made his early philosophy so sound and so full of meaning for the perfection of the human understanding. On the other hand, when you come to a further development of the same philosophy, namely, that of Fichte, there the speculative part vanishes entirely into insignificance, because that which Fichte taught was not such kind of nonsense as that which I have read to you, but it was a kind of moral philosophy which spoke to the youth of Germany, and taught them this one great proposition, which every one of them ought to feel, and which is the first condition of self-consciousness in man, namely, "I am I;" this was the great teaching of Fichte, by which he brought home to men their own value and their own powers, which cannot be said was the result of the other philosophy from which I have quoted.

In 1822 Liebig, having emancipated himself from this kind of teaching, took the degree of Doctor of Philosophy at Erlangen, when he was nineteen years old. In the autumn of that year he returned to Darmstadt; his researches and endeavors then became known, and he attracted the attention of the Grand-duke Ludwig I., of Hesse-Darmstadt, who conferred upon him a state stipend, to enable him to continue his studies at Paris. To Paris, therefore, he went. Now let us for a moment consider what was then the condition of chemistry at Paris. Lavoisier, the great reformer, who. had established what was then called the antiphlogistic chemistry, had thirty years before died on the scaffold; Guyton de Morveau, Fourcroy, and Berthollet, whom the first Napoleon called the plus brave des Français, because he gave him chlorate of potassium, by which he hoped to overcome the want of nitre for his gunpowder; the great Société d'Arcueil, which worked through the whole of the war-times zealously at science, and published its memoirs—all these men had passed away. But there remained their disciples in the persons of Proust, Chevreul, Vauquelin, Gay-Lussac, Thénard, and Dulong. Chevreul is the only one of these celebrated men who now lives, and he has lately published, in the Comptes Rendus, a very remarkable paper on the changes which are produced in the power of thinking and observing by age. Fourcroy, the great animal chemist, who, in connection with Vauquelin, laid the foundation of that physiological chemistry on which the modern science is based; then Gay-Lussac, Thénard, and Dulong, men of the new science, who continued the work in a most glorious manner, which in this country had been carried to such a glorious issue by Humphry Davy—these men were at that time teaching at Paris, and at the laboratory which the liberality of the first Napoleon and his envy of English discoveries had established at L'École Polytechnique. They contiued to study and shape the new science which was destined to give to the modern science of chemistry precision.

Liebig then worked with Thénard, listened to Gay-Lussac's lectures, and he met there the young German chemists, Runge, well known by his many researches on tar, and the tar products; Mitscherlich, the discoverer of isomorphism and polymorphism; Gustav Rose, the representative of the perfection of analytical and inorganic chemistry. In 1823 he brought his first paper on the fulminates of silver and mercury before the Academy. And now, let me quote to you what he says of that event in the first work which he ever published. In the preface, which is a dedication to Alexander von Humboldt, he says that at the meeting of the Academy, on the 28th of July, 1823, he had read his paper, and was just engaged in packing up his apparatus and preparations, when a man, one of the members of the Academy, approached him, entered into conversation with him, and in an incredibly short space of time knew how to elicit from him all his hopes, schemes, and intentions. He did not dare to ask, either from shyness or from accident, who the gentleman was who spoke to him, and he disappeared again among the academicians. But he says: "From that day all the doors of society, and of all institutions, were open to me. I did not know until many years afterward to whom I owed this introduction and favor." It was to Humboldt, who had so well recommended him to the great French chemists that Gay-Lussac, who never took any pupil whatever into his laboratory, accepted him as his only pupil, and, more than that, joined with him in his continuation of those researches which at that early age he had brought to such perfection. This preface is beautiful in its conception and feeling, and has been printed in all the seven editions of the work which have since been published. If there were time this would, perhaps, be the place to show the wonderful influence which Humboldt has exercised upon the science of all countries; but I must pass over that subject, and continue the account of Liebig's life.

Through the recommendations of Humboldt and Gay-Lussac, both of which were addressed directly to the Grand-duke of Hesse-Darmstadt, Liebig was, at the age of twenty-one years, by the supreme will and absolute power of the grand-duke, appointed first Professor of Chemistry in the University of Giessen. A new chair was established for him, and as a laboratory he received a room, as he expresses it, with four walls. Great was the opposition against this new professor; for what was chemistry? Chemistry was no science, nobody knew anything of chemistry, nobody would have it. Moreover, the appointment had not been made in the regular way, therefore the whole of the authorities of the university set themselves against it. The consequence was that the majority of that university persecuted that man for twenty-seven years; and, no matter what was his reputation, the amount of his work, or the importance of his position, for twenty-seven years this man could never once be made Rector of the University of Giessen. But where are the opposing influences now? History will not mention their names. Their ultramontane participators tried to decry the great man as an atheist and materialist, and by that means to remove from him the assistance of the state, and to diminish his chance of gaining a living. But he was too strong for all of them. In the year 1826 he was appointed Professor in Ordinary, a promotion by which he became a fixed servant of the state and a fixed member of the university. In that year he married Henrietta Moldenhauer, a most amiable lady, who now survives him.

Now comes the period of work which lasted to the year 1834. The work itself I will not now enter upon, but we will, in future lectures, see what was the nature of that work. We will perform before your eyes some of those operations by which that work has become of the utmost importance to mankind at large; and you can then see how, from a small point, there can be a light shed upon the largest problems of science.

In this year 1834, however, Liebig fell ill from overwork and anxiety. A portrait, which was taken at that time by the now deceased painter Engel, gives evidence of that, and I remember that the late Prof. Zamminer told me that he had seen Liebig about that time taking short walks in the evening air, looking pale and haggard, like a man in consumption, with little spots of hectic on his cheeks, and that his friends were afraid he would soon die. At that time he retired from Giessen for a while, and went to Baden-Baden, in the hope of recruiting his health. The patience which he had exercised for many years, under the most narrow arrangements, then gave way, and he asked for the building of a new lecture-room, the arrangement of a proper laboratory, and for an increase of salary. All was refused by the narrow-minded Government of Hesse-Darmstadt, through that close-minded man, the then chancellor, Von Linde. Then Liebig wrote to Von Linde a letter, in which, after the introduction, he continues thus:

"I should have gained some convenience by these arrangements, but they were not intended for me personally; they would have been of lasting value for the university, and would have secured to the chemical chair an advantage over

all others in Germany. For the institutions of a university the largest sums may be expended, for this increases the respect and affection for them; but the suitable employment of these sums must be strictly controlled. The sums are there, but they are used in an intolerably ridiculous manner. I must be certain of what I may have to expect at Giessen. If driven to extremities I shall not return there this winter, whether I obtain leave or not. I shall know how to justify this step, for no one has been maltreated in the university in a more conspicuous manner. One cannot live at Giessen upon a salary of 800 florins. Four years ago I, in conjunction with four colleagues, asked for an increase of salary; it has been refused. You (the Chancellor von Linde) have assured me with smiles that the state treasury had no funds; from this I saw that you have never known grief and torturing care for the daily bread. From the moment of that refusal I have endeavored to acquire an independent position by ceaseless work; my exertions have not been without success, but they have surpassed my strength, and I have become an invalid; and if now, when I do not require the state any longer, I consider that with a few miserable hundred florins more my health need not have suffered in former years, because my life would have been more free from care, the hardest thought for me is that my situation was known to you. The means which the laboratory possesses have been too small from the beginning. I had four walls given to me instead of a furnished laboratory. Notwithstanding my requests, no sum for furnishing the same, or for buying apparatus, has been provided. I required instruments and specimens, and have been obliged to spend on these items annually from 300 to 400 florins from my own means; besides the famulus paid by the state I required an assistant, who costs me 320 florins—deduct both expenses from my salary, and there remains not enough to clothe my children. From this original treatment of the laboratory the consequence has arisen that it possesses no property, for I can show that the arrangements, fittings, instruments, specimens, which have made the Giessen laboratory—I can say it without blushing—the first in Germany, are my property. I will say nothing more about myself my account with Giessen is closed. My path is not the one of reptiles, the easiest though the dirtiest. What I have said will suffice to justify with the ministry and the prince my resolution not to lecture at Giessen during this winter (1834—'35). If I am in health I may not lack the power to establish a kind of university for my branches of science at my own risk. If I am not permitted, and if I receive my congé, this will free me from the charge of ingratitude toward the country from the means of which my scientific training has been possible. I have learned to bear much injustice, many a false judgment, but this reproach of ingratitude would be too heavy for me to bear."

This letter pictures to you the conditions which prevailed at Darmstadt, but it is still more important, because it shows that such strong language was required to bring down the ministry, and that which no kind of friendly representation had been able to effect, this threat did. In 1835 he had to take compulsory repose. I find in the list of his publications only three small papers dating from this period, of which one only was a research; but in almost every other year there were from ten to twenty researches and publications.

In 1836 another active period begins. In that year there were nine researches by himself alone, thirteen by himself and Pelouze. In 1837 there were nine researches by himself and five with Wöhler, including the celebrated one on lithic acid, and two with the celebrated French chemist Dumas. In that year the British Association for the Advancement of Science, at their Liverpool meeting, made a request to him to write a report on the then state of knowledge of organic chemistry. It was this report which originated the work which he published in 1840, namely, the work entitled "Organic Chemistry in its Application to Agriculture and Physiology." In 1838 he published a memoir on the state of chemistry in Austria, in which he exhibited its shortcomings in trenchant language, and the effect upon the Austrian Government was such as no one would have expected. In reply to his essay he received the offer of a chair at Vienna. "Come to us," they said, "reform our chemistry, and we will give you a chair." But the conditions were not sufficient, and the Austrian Government, having received Liebig's refusal to go to Vienna, at their own expense sent a number of young chemists to Giessen, there to study chemistry under Liebig, and to prepare themselves for the important function of becoming teachers of the new chemistry in Austria. In the year 1840 he published the work which I have already mentioned, and he also published a memoir on the state of chemistry in Prussia. You know what was the state of Prussia in 1840; the promises made by the king in the year 1813, regarding a liberal constitution, had all been falsified, a narrow-minded bureaucracy governed everything, a minister of education who did not comprehend his time could not understand that physical science required any promotion, or any state help. He soon went into that movement which has been described as Muckerthum, a kind of pietism which shows itself by casting up the eyes in a praying attitude, having God more on the tongue than in the heart; by a mock-modest morality which would, for example, have caused the council of this institution to have those beautiful nymphs on our walls painted over with drapery. Under these circumstances no science could progress, and there was not in the whole of Prussia a single establishment, laboratory, or teaching-room where a man could learn practical or even theoretical chemistry. It was the great boast of even talented teachers of chemistry, that all the apparatus they required for teaching was a dozen test-tubes. This attack on the state of chemistry in Prussia had no effect whatever of a good kind, but, on the contrary, the bureaucracy used its power and influence to prevent the Prussian youth from visiting the University of Giessen, and I have the authority of Kolbe that for a time the visiting this university was actually forbidden to young Prussians.

About this period Liebig purchased from the municipality of Giessen a sand-pit, at a place called Trieb, on a little height east of the town, and there he made experiments on vegetable physiology. This place bears the name of "Liebig's Height" to the present day, and I dare say it will bear it for many years to come. He also published his work on "Chemistry in its Application to Physiology and Pathology," which he dedicated to Berzelius. In 1844 appeared his first "Familiar Letters on Chemistry," in the Augsburg Gazette. These letters were afterward published with many new ones from time to time in several editions, and by this means he contributed greatly to make chemistry popular, while still keeping it in the most scientific form needful. In 1850 he published a pamphlet on spontaneous combustion, on the occasion of the death of the Countess Görlitz, who had by experts and doctors at Darmstadt and Giessen been declared to have perished from spontaneous combustion, but it was afterward found out that she had not perished in that way, but that she had been murdered by her butler, and afterward burnt. About this time also Liebig effected a reform in the medical studies and examinations in the University of Giessen, and this reform was so important, and effected by so great a participation of public opinion, that we see there how great was his power, although in the university itself he was kept out of office as far as possible. These reforms amounted to nothing less than this—complete liberty of study. You know that in this country medical students have no liberty of study; they are obliged to attend lectures, to have heard at least two-thirds of the lectures given, and if it is not certified by the beadle, who comes in to every lecture and takes the names of all present, that they have been present at two-thirds of the lectures, they are not allowed to enter for the examination. This state of things also existed in the German universities previous to this reformation. At that time, however, this was completely done away with, and every student was allowed to obtain his knowledge where and how he pleased. He was not obliged to enter any university whatever, but he was obliged to pass an examination, and to pass that examination publicly, an examination which should so thoroughly test his knowledge that, after he had passed it there could be no doubt whatever about his fitness to follow his profession. Now let me recommend to your attention this most remarkable system of public examination. The extraordinary effect it had on the University of Giessen was this, that, whereas formerly many students coming unprepared were rejected, since the introduction of public examinations few rejections have taken place, because the students take great care to get up their subjects and to come so fully prepared that, in the presence of their countrymen, in the presence of any person who likes to enter the hall when the examination takes place, they can show that they are fit to follow their profession.

I have already, I see, passed the time allotted to me, and I shall not detain you many more minutes. In the autumn of the year 1852 Liebig left Giessen, having received a call to the University of Münich, where the then King Maximilian was desirous of following his father, Ludwig, on another path of glory. You know that Ludwig had made it his life-business to restore art in Germany and raise it to a high footing in Bavaria, and Maximilian now wished to do the same thing for science in general, and he therefore endeavored to collect from all parts of Germany the best men whom he could attract. One of these was Liebig, the king having made him president of the Academy, with the condition that he should undertake no laboratory teaching; that he should deliver lectures only, and at the same time be the Curator of the Botanical Gardens. In that position he remained up to his death, devoting himself mainly to the public part of his duties, which he performed with grace, honor, and glory, and in the laboratory which had been constructed for his own immediate wants he only performed such analyses, partly himself, and partly by a number of assistants, as were necessary to give him the data for the publication of his several works.

At last, in the year 1873, on April 18th, he died, nearly seventy years of age, and in full possession of his faculties, not having, as other philosophers have had the pain of doing, experienced any diminution of his mental powers.

  1. From the "Cantor Lectures" delivered before the Society of Arts.