Louis Duport was the author of a tolerable number of cello compositions. They consist of four books of Sonatas with bass accompaniment, three Duets for two violoncellos, and eight “Airs Variés” with orchestra or quartet accompaniment. Besides these he composed, in connection with Bochsa, nine Nocturnes for harp and violoncello, a “Fantasie” for piano and violoncello in conjunction with Rigel, and a Romance with piano accompaniment. As his _chef d’œuvre_ must be distinguished: “Essai sur le doigter du violoncelle et la conduite de l’archet, dédie aux professeurs de violoncelle.” This comprehensive instruction book, for which the materials were collected by degrees during a long period of years, was published by Duport during his residences in Berlin and Potsdam. In the preface he says: “I have treated with minute detail the subject of double-stops, and this I have done for two reasons: the first is that until now nothing concerning them has been written,[91] and they are so important for a good player; the second, because they have so often served me as an argument, for without an established mode of fingering, double notes are impossible. In the course of this work things will be met with of which the performance is difficult, but nothing will be presented which is really impracticable. I am not writing a useless theory. I have put down no scales, no figures, no passages, no exercises, without having repeatedly tried them myself. I caused them to be repeatedly played by my brother, who was formerly my master, and will ever remain so, as well as by the best of my pupils in Berlin and Potsdam. I am therefore thoroughly convinced that the work contains nothing that may not with ease be clearly and distinctly carried out, and what at first appears impracticable will be practicable for those who will give themselves continuous trouble, and make a point of practising a regular course of fingering.” It is evident that Duport devoted himself with the greatest care to the working out of his book of instruction (which must be accounted a violoncello school) in order to bring about distinctness in the finger technique, not until then fully settled. For that time it was a meritorious undertaking. A new edition of it, brought out by the violoncellist, A. Lindner, is a proof that the work, in spite of its age, is not quite without value. It is only to be regretted that the original text has not throughout been faithfully adhered to, and that in parts it has been suppressed. The editor should have reproduced the work in its original form, and have enunciated his own dissenting opinions in observations.