On his return from Vienna, Franz Anton, finding that a new kapellmeister had been chosen in his place, accepted the humbler position of “Stadt Musikant.” This, however, he soon relinquished; and for some years he wandered from town to town, giving dramatic performances, in conjunction with the children of his first wife, wherever he could collect an audience. The effect of this restless life upon the little Carl Maria’s health and education was deplorable; but, as he accompanied his father everywhere, he became familiarized with the stage from his earliest infancy, and thus gained an amount of dramatic experience that indisputably laid the foundation of his future greatness. Franz Anton hoped to see him develop into an infant prodigy, like his cousin Mozart, whose marvellous career was then rapidly approaching its close. In furtherance of this scheme, the child was taught to sing and place his fingers upon the pianoforte almost as soon as he could speak, though he was unable to walk until he was four years old. Happily his power of observation and aptitude for general learning were so precocious that he seems, in spite of all these disadvantages, to have instinctively educated himself as became a gentleman. His first music-master was Keuschler, who gave him instruction at Weimar in 1796. In 1798 Michael Haydn taught him gratuitously at Salzburg. In the March of that year his mother died, like her predecessor, of chagrin. In April the family visited Vienna, removing in the autumn to Munich. Here the child’s first composition—a set of “Six Fughettas” —was published, with a pompous dedication to his halfbrother Edmund; and here also he took lessons in singing from Valesi, and in composition from Kalcher, under whom he made rapid progress. Soon after this he began to play successfully in public, and his father compelled him to write incessantly. Among the compositions of this period were a mass and an opera— Die Macht der Liebe und des Weins— now destroyed. A set of “Variations for the Pianoforte,” composed a little later, and dedicated to Kalcher, was lithographed by Carl Maria himself, under the guidance of Senefelder, the inventor of the process, in which both the father and the child took great interest.

In 1800 the family removed to Freiberg, where the Ritter von Steinsberg gave Carl Maria the libretto of an opera called Das Waldmädchen, which the boy, though not yet fourteen years old, at once set to music, and produced in November at the Freiberg theatre. The performance was by no means successful, and the composer himself was accustomed to speak of the work as “a very immature production”; yet it was afterwards reproduced at Chemnitz, and even at Vienna.

Carl Maria returned with his father to Salzburg in 1801, resuming his studies under Michael Haydn, and forming a close friendship with the Chevalier Neukomm. Here also he composed his second opera, Peter Schmoll und seine Nachbarn, which was unsuccessfully produced at Nuremberg in 1803. In that year he again visited Vienna, where, though the veterans Haydn and Albrechtsberger were both receiving pupils, his father preferred placing him under the Abbé Vogler, a man of kind and sympathetic nature, but quite unfit to train so great a genius. Through Vogler’s instrumentality Carl Maria was appointed conductor of the opera at Breslau, before he had completed his eighteenth year. In this capacity he greatly enlarged his experience of the stage; but he lived a sadly irregular life, contracted debts which his slender salary was insufficient to defray, and lost his beautiful voice through accidentally drinking a poisonous liquid used in lithography,—a mishap that nearly cost him his life. These hindrances, however, did not prevent him from beginning a new opera called Rübezahl, the libretto of which was based upon a well-known legend of the Riesengebirge. The plot of the piece was “romantic” to the last degree, and Weber worked at it enthusiastically, but it was never completed, and little of it has been preserved beyond a quintett and the masterly overture, which, re-written in 1811 under the title of Der Beherrscher der Geister, now ranks among its author’s finest instrumental compositions.

Quitting Breslau in 1806, Weber removed in the following year to Stuttgart, where he had been offered the post of private secretary to Duke Ludwig, brother of Frederick, king of Würtemberg. The appointment was a disastrous one. The stipend attached to it was insufficient to meet the twofold demands of the young man’s new social position and the thriftlessness of his father, who was entirely dependent upon him for support. Court life at Stuttgart was uncongenial to him, though he yielded to its temptations. The king hated him. He fell hopelessly into debt, and, worse than all, became involved in a fatal intimacy with Margarethe Lang, a singer at the opera. Notwithstanding these distractions he worked hard, and in 1809 re-modelled Das Waldmädchen, under the title of Sylvana, and prepared to produce it at the court theatre. But a dreadful calamity prevented its performance. Franz Anton had misappropriated a large sum of money placed in the young secretary’s hands for the purpose of clearing a mortgage upon one of the duke’s estates. Both father and son were charged with embezzlement, and, on February 9, 1810, they were arrested at the theatre, during a rehearsal of Sylvana, and thrown by the king’s order into prison. No one doubted Weber’s innocence, but after a summary trial he and his father were ordered to quit the country, and on February 27 they began a new life at Mannheim.

Having provided a comfortable home for his father, and begun the composition of a new comic opera, in one act, called Abu Hassan, Weber removed to Darmstadt in order to be near his old master the Abbé Vogler, and his fellow-pupils Meyerbeer and Gänsbacher, with whom he lived on terms of the closest intimacy. On September 16, 1810, he reproduced Sylvana under its new title at Frankfort, but with very doubtful success. Abu Hassan was completed at Darmstadt in January 1811, after many interruptions, one of which exercised a memorable influence upon his later career. While reading with his friend, Alexander von Dusch, George Apel’s then recently published Gespensterbuch, he was so much struck with the story of Der Freischütz that he at once began to meditate upon its transformation into an opera, and the two friends actually set to work upon it then and there. But it was not until many years afterwards that the idea was carried out in a practical form.

Weber started in February 1811 on an extended artistic tour, during the course of which he made many influential friends, and on June 4 brought out Abu Hassan with marked success at Munich. His father died at Mannheim in 1812, and after this he had no settled home, until in 1813 his wanderings were brought to an end by the unexpected offer of an appointment as kapellmeister at Prague, coupled with the duty of entirely remodelling the performances at the opera-house. The terms were so liberal that he accepted at once, engaged a new company of performers, and governed them with uninterrupted success until the autumn of 1816. During this period he composed no new operas, but he had already written much of his best pianoforte music, and played it with never-failing success, while the disturbed state of Europe inspired him with some of the finest patriotic melodies in existence. First among these stand ten songs from Körner’s Leyer und Schwerdt, including “Vater, ich rufe dich,” and “Lützow’s wilde Jagd”; and in no respect inferior to these are the splendid choruses in his cantata Kampf und Sieg, which was first performed at Prague, December 22, 1815.

Weber resigned his office at Prague, September 30, 1816, and on December 21 Frederick Augustus, king of Saxony, appointed him kapellmeister at the German opera at Dresden. The Italian operas performed at the court theatre were superintended by Morlacchi, whose jealous and intriguing disposition produced an endless amount of trouble and annoyance. The king, however, placed the two kapellmeisters on an exact equality both of title and salary, and Weber found ample opportunity for the exercise of his remarkable power of organization and control. And now he once more gave his attention to the story of Der Freischütz, which, with the assistance of Friedrich Kind, he developed into an admirable libretto, under the title of Des Jägers Braut.

The legend of “The Seventh Bullet,” though well known in the 17th century, and probably much earlier, seems to have been first given to the world in a connected form in a work entitled Unterredungen vom Reiche der Geister, the second edition of which was printed at Leipsic in 1731. In this version of the story the scene is laid in Bohemia, and the action referred to the year 1710. Apel reproduced the legend, under the title of “Der Freischütz,” in the first volume of his Gespensterbuch, in 1810. Since then the story has been repeated in many varying forms, but it was Apel’s version that first attracted Weber’s attention, and it was from this that he and Kind together made their first sketch of the libretto, on February 21, 1817, though they found it necessary to increase the interest of the drama by the introduction of some accessory characters, and to substitute a happy ending for the fatal catastrophe of the original story. No subject could have been better fitted than this to serve as a vehicle for the new art-form which, under Weber’s skilful management, developed into what is now universally recognized as the prototype of the true “romantic opera.” He had dealt with the supernatural in Rübezahl, and in Sylvana with the pomp and circumstance of chivalry, but in neither case with the unquestioning faith which alone can invest the treatment of such subjects with befitting dignity. The shadowy impersonations in Rübezahl are scarcely less human than the heroine who invokes them; and the music of Sylvana might easily have been adapted to a story of the 19th century. But in the master’s later operas all this is changed. We cannot choose but shudder at the fiend in Der Freischütz, for the infernal apparition comes straight to us from the nether world. Every note in Euryanthe breathes the spirit of mediaeval romance; and the fairies in Oberon have a real existence, quite distinct from the tinsel of the stage. And this it is,—this uncompromising reality, even in face of the unreal,—that forms the strongest characteristic of the pure “romantic school,” as Weber understood and created it. It is true to nature even when dealing with the supernatural, for it treats its wildest subjects in earnest, and without a doubt as to the reality of the scenes it ventures to depict, or the truthfulness of their dramatic interpretation.

Weber and Kind sketched the scenario of the new opera in February 1817. On March 1 the poet placed the complete libretto in the hands of the composer, who wrote the first note of the music on July 2—beginning with the duet which opens the second act. But so numerous were the interruptions caused by Morlacchi’s intrigues, the insolence of unfriendly courtiers, and the attacks of jealous critics that nearly three years elapsed before the piece was completed. In the meantime the performances at the opera-house were no less successfully remodelled at Dresden than they had already been at Prague, though the work of reformation was far more difficult; for the new kapellmeister was surrounded by enemies who openly subjected him to every possible annoyance, and even the king himself was at one time strongly prejudiced against him. Happily, he no longer stood alone in the world. Having, after much difficulty, broken off his miserable intimacy with Margarethe Lang, he married the well-known vocalist, Carolina Brandt, a noble-minded woman and consummate artiste, whose advice, even on subjects connected with the new opera, was extremely valuable. The great work was completed May 13, 1820, on which day Weber wrote the last note of the overture,—a portion of the design which, for obvious reasons, it was his custom to postpone until the rest of the music was finished. There is abundant evidence to prove that he was well satisfied with the result of his labours; but he gave himself no rest. He had engaged to compose the music to Wolff’s Gipsy drama, Preciosa. Two months later this also was finished, and both pieces ready for the stage.

In consequence of the unsatisfactory state of affairs at Dresden, it had been arranged that both Preciosa and Der Freischütz— no longer known by its original title, Des Jagers Braut— should be produced at Berlin. In February 1821 Sir Julius Benedict was accepted by Weber as a pupil; and to his pen we owe a delightful account of the rehearsals and first performance of his master’s chef d'oeuvre. Preciosa was produced with great success at the old Berlin opera-house on June 14, 1821. On June 18, the anniversary of the battle of Waterloo, the opening of the new “Schauspielhaus” was celebrated by the production of Der Freischütz. Much anxiety was caused by unforeseen difficulties at the rehearsals; yet, so calm was Weber’s mind that he devoted his leisure time to the composition of his Concertstück in F minor—one of his finest pianoforte pieces. Until the last moment his friends were anxious; the author was not; and the result justified his confidence in his own powers. The success of the piece was triumphant. The work was received with equal enthusiasm at Vienna on October 3, and at Dresden on January 2G, 1822. Yet Weber’s position as kapellmeister was not much improved by his success, though, in order to remain faithful to his engagements, he had refused tempting offers at Berlin and Cassel, and, at the last-named place, had installed Ludwig Spohr in a position much more advantageous than his own.

For his next opera Weber accepted a libretto based, by Frau Wilhelmine von Chezy, on the story of Euryanthe, as originally told in the 13th century, in Gilbert de Montreuil’s Roman de la Violette, and repeated with alterations in the Decamerone, in Shakespeare’s Cymbeline, and in several later forms. In place of the ghostly horrors of Der Freischütz, the romantic element was here supplied by the chivalric pomp of the Middle Ages. The libretto, though soundly abused by shallow critics, is really an exceptionally good one—in one respect superior to that of Der Freischütz, inasmuch as it substitutes elaborate recitative for the spoken dialogue peculiar to the German “Schauspiel” and French “opéra comique.” It is, in fact, a “grand opera” in every sense of the words,—the prototype of the “musical drama” perfected fifty years later by Wagner. The overture—as usual, written last— presents a feature that has never been imitated. During its performance the curtain temporarily rises, to exhibit, in a tableau vivant, the scene in the sepulchral vault upon which the whole story turns. This episode is now rarely presented; but Weber himself well knew how much the interest of the piece depended on it. The work was produced at the Kärntnerthor theatre in Vienna, October 25, 1823, and received with enthusiasm. Being of a less popular character than Der Freischütz, it is not so frequently performed; but it still retains its place upon the stage, and ranks among the finest “romantic operas” that have ever been written.

Weber’s third and last dramatic masterpiece was an English opera, written for Covent Garden theatre, upon a libretto adapted by Planché from Wieland’s Oberon. Destined for the English stage sixty years ago, this was necessarily disfigured by the spoken dialogue abandoned in Euryanthe ; but in musical beauty it is quite equal to it, while its fairies and mermaids are as vividly real as the spectres in Der Freischütz. Though already far gone in consumption, Weber began to compose the music on January 23, 1825. Charles Kemble had offered him £1000 for the work, and he could not afford to rest. He finished the overture in London, at the house of Sir George Smart, soon after his arrival, in March 1826; and on April 12 the work was produced with triumphant success. But it cost the composer his life. Wearied out with rehearsals and performances of the opera, and concerts at which he was received with rapturous applause, he grew daily perceptibly weaker; and, notwithstanding the care of his kind host, Sir George Smart, and his family, he was found dead in his bed on the morning of June 5, 1826. For eighteen years his remains rested in a temporary grave in Moorfields chapel; but in 1844 they were removed and placed in the family vault at Dresden.

Besides his three great dramatic masterpieces and the other works already mentioned, Weber wrote two masses, two symphonies, eight cantatas, and a vast amount of songs, orchestral and pianoforte pieces, and music of other kinds, amounting altogether to more than 250 compositions.

As we have no means of subjectively measuring the absolute intensity of our sensations, it is necessary to depend upon the mental estimate or comparison of two or more sensations. Comparison enables us to say whether they are equal in intensity, or if unequal which is the greater and which is the less. But as they approach equality in this respect it becomes more and more difficult to detect the difference. By a series of experiments, therefore, it will be possible, in the case of any particular individual, to determine the least observable difference in intensity between two sensations of any particular sense. This least observable difference is called by Fechner the “Unterschiedsschwelle,” or “difference-threshold,” that is to say, the limit of the discriminative sensibility of the sense in question. That such a “threshold,” or least observable difference, exists is plain from very simple examples. Very small increases may be made in the objective amount of light, sound, or pressure—that is, in the physical stimuli applied to these senses—without the subject on whom the experiment is made detecting any change. It is further evident that, by means of this “Unterschiedsschwelle,” it is possible to compare the discriminative sensibility of different individuals, or of different senses, or (as in the case of the skin) of different parts of the same sense organ: the smaller the difference observable the finer the discriminative sensibility. Thus the discrimination of the muscular sense is much more delicate than that of the sense of touch or pressure, and the discriminative sensibility of the skin and the retina varies very much according to the parts of the surface affected. Various methods have been adopted with a view to determine these minima of discriminative sensibility with an approach to scientific precision. The first is that employed by Weber himself, and has been named the method of just observable differences. It consists either in gradually adding to a given stimulus small amounts which at first cause no perceptible difference in sensation but at a certain point do cause a difference to emerge in consciousness, or, vice versa, in gradually decreasing the amount of additional stimulus, till the difference originally perceived becomes imperceptible. By taking the average of a number of such results, the minimum may be determined with tolerable accuracy. The second method is called by Fechner the method of correct and incorrect instances. When two stimuli are very nearly equal the subject will often fail to recognize which is the greater, saying sometimes that A is greater, sometimes that B is greater. When in a large number of trials the right and wrong guesses exactly balance one another we may conclude that the difference between the two stimuli is not appreciable by the sense. On the other hand, as soon as the number of correct guesses definitely exceeds half of the total number of cases, it may be inferred that there is a certain subjective appreciation of difference. This method was first employed by Vierordt. The third method, that of average errors, is very similar to the one just explained. Here a certain weight (to take a concrete example) is laid upon the hand of the person experimented upon, and he is asked, by the aid of subjective impression alone, to fix upon a second weight exactly equal to the first. It is found that the second weight sometimes slightly exceeds the first, sometimes slightly falls below it. Whether above or below is of no consequence to the method, which depends solely on the amount of the error. After a number of experiments, the different errors are added together, and the result being divided by the number of experiments gives us the average error which the subject may be calculated upon to make. This marks the amount of stimulus which is just below the difference-threshold for him. This method was first employed by Fechner and Volkmann. The different methods were first named, and the theory of their application developed by Fechner, in his Elemente der Psychophysik (1860).

These methods have been chiefly applied to determine the relation of the difference-threshold to the absolute magnitude of the stimuli employed. For a very little reflexion tells us that the smallest perceivable difference is not an amount whose absolute intensity is constant even within the same sense. It varies with the intensity of the stimuli employed. We are unable, for example, to recognize slight differences in weight when the weights compared are heavy, though we should be perfectly able to make the distinction if the weights compared were both light. Ordinary observation would lead us, therefore, to the conclusion that the greater the intensity of the original stimulus at work the greater must be the increase of stimulus in order that there may be a perceptible difference in the resulting sensation. E. H. Weber (1795-1878) was the first (after a prolonged series of experiments on the sensations of sight, hearing, and touch) to clothe this generality with scientific precision by formulating the law which has since gone by his name. The purport of the law is that, in order that the sensational difference may remain unchanged, the increase of stimulus must maintain the same proportion to the intensity of the preceding stimulus. The smallest perceptible difference is therefore not absolutely the same, but it remains relatively the same, that is, it remains the same fraction of the preceding stimulus. For example, if we can distinguish 16 oz. and 17 oz., we shall be able to distinguish 32 oz. and 34 oz. but not 32 oz. and 33 oz., the addition being in each case 1 / 16 of the preceding stimulus. This fraction (supposing it to be the difference-threshold of the muscular sense) remains a constant, however light or however heavy the weights compared. The law may be formulated thus :—The difference between any two stimuli is experienced as of equal magnitude, in case the mathematical relation of these stimuli remains unaltered. Or, otherwise expressed, In order that the intensity of a sensation may increase in arithmetical progression, the stimulus must increase in geometrical progression. It is also expressed by Fechner in the form— The sensation increases as the logarithm of the stimulus.

The law has been variously interpreted. Fechner himself designated it the psycho-physical law, and treated it as the fundamental formula of the relation between body and mind, thus assigning to it an ontological dignity and significance. But in this “psycho-physical” interpretation of his results he has not had a numerous following. Wundt interprets the law in a purely “psychological” sense, making it a special instance of the general law of relativity which governs our mental states. Introspection can give us no information as to the absolute intensity of the stimulus; for a stimulus is known in consciousness only through its sensational resultant. Hence, he argues, we can only compare one psychical state with another, and our standard of measurement is therefore necessarily a relative one; it depends directly upon the preceding state with which we compare the present. Others have attempted to give the law a purely physical or “physiological” explanation. Instead of holding with Fechner that the law expresses a recondite relation between the material and the spiritual world, they prefer to regard the quantitative relation between the last physical antecedent in the brain and the resultant mental change as prima facie one of simple proportion, and to treat Weber’s law as holding between the initial physical stimulus and the final action of the nerve-centres. According to this interpretation, the law would be altogether due to the nature of nervous action. As a nerve, says Sully, after a temporary degree of stimulation temporarily loses its sensibility, so the greater the previous stimulation of a nerve the greater is the additional stimulus required to produce an appreciable amount of sensation.

Weber’s law, it must be added, holds only within certain limits. In the “chemical” senses of taste and smell experiments are almost impossible. It is not practicable to limit the amount of the stimulus with the necessary exactitude, and the results are further vitiated by the long continuance of the physiological effects. The same considerations apply with still more force to the organic sensations, and the results in the case of temperature sensations are completely uncertain. The law is approximately true in the case of sight, hearing, pressure, and the muscular sense,—most exactly in the case of sound. As this is the sense which affords the greatest facilities for measuring the precise amount of the stimulus, it may perhaps be inferred that, if we could attain the same exactitude in the other senses, with the elimination of the numerous disturbing extraneous influences at work, the law would vindicate itself with the same exactitude and certainty. It is further to be noted, however, that even in those senses in which it has been approximately verified, the law holds with stringency only within certain limits. The results are most exact in the middle regions of the sensory scale; on the contrary, when we approach the upper or lower limit of sensibility, they become quite uncertain.

Literature.— Weber’s investigations were given to the public in his articles in Wagner’s Handwörterbuch der Physiologie. Fechner’s Elemente der Psycho-physik, referred to above, was published in 1860, and contains an elaborate exposition of the whole subject. He replied to his critics in two later works, In Sachen der Psychophysik (1877) and Revision der Hauptpunkte der Psycho-physik (1882). Delboeuf’s Étude psychophysique (1873), and G. E. Müller's Zur Grundlegung der Psycho-physik, are also important documents; and the subject is fully treated in Wundt's Physiologische Psychologie and in Ladd’s Physiological Psychology, which is based upon Wundt. Two English monographs may be referred to as containing important criticisms of the law,—the paper of Messrs Dewar and M‘Kendrick in the Transactions of the Royal Society of Edinburgh for 1873, and Mr James Ward’s “Attempt to Interpret Fechner’s Law,” in Mind, i. 452 sq.