For some thousands of years this question remained in the stage of pure empiricism, or of so-called scientific speculations which had scarcely a better reputation than alchemy, astrology, or chiromancy. J. Müller, in the name of physiology, declared the expression of the emotions completely inexplicable. However, the researches were already beginning which were to prove him mistaken—those of Lavater with his rare talent of personal observation, and those of Charles Bell by a more objective method. After this, Duchenne, of Boulogne, went still further, substituting experiment for mere observation. It is well known that, in the case of an old man suffering from facial anæsthesia, he caused the contraction of an isolated muscle, by the aid of electricity, and thus produced certain modes of expression in the countenance. He concluded from this that the contraction of a single muscle often suffices to express a passion; and that every emotion has, so to speak, its accurate, precise, and unique note, produced by a unique local modification. Thus, the frontal is for him the muscle of attention, the upper orbicular of the lips the muscle of reflection, the pyramidal (inter-superciliary) expresses threats; the great zygomatic, laughter; the lesser zygomatic, weeping; the triangular muscle of the lips, disdain, etc. In spite of the somewhat artificial nature of the experiments, and the too sweeping character of the conclusions, this was a great step in advance.[85] Footnote 85: Lavater (1741-1801), _Essai sur la physionomie destiné à faire connaître l’homme et à le faire aimer_; Charles Bell (1806), _Anatomy and Philosophy of Expression_; Duchenne (1862), _Mécanisme de la physionomie humaine, ou analyse électro-physiologique de l’expression des passions_. For ancient works on physiognomy, consult Mantegazza’s book on _Physiognomy and Expression_ (Contemporary Science Series). At last appeared Darwin’s epoch-making work. Supported by the results of a long series of experiments on adults, children, lunatics, animals, members of the different human races, Darwin was the first to put, and to attempt to answer, the fundamental and only question—Why and how is such and such an emotion connected with such and such a movement and not with another? He stated the problem under its scientific form.[86] Footnote 86: