Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

When the muscle frontalis is slightly contracted, the face cheers up ; then, when more contracted, its expression is changed to surprise, and then even to doubt; if in the highest degree of contraction, and assisted by other muscles, it produces the agreeable surprise, and so on to terror. This muscle wrinkles the forehead; therefore, when it is paralyzed, the wrinkles can- not be produced. The paramidalis nasi, which is but a nasal elongation of the frontalis, acts, however, as the antagonistic of the frontalis, and when contracted, therefore, gives the expres- sion of sadness; when more contracted, a threatening aspect. When the orbicularis palpebrarum and corrugator supercilii are both contracted, there is produced the expression of reflec- tion and perplexity; and when aided by the pyramidalis, there is the expression of malice. We see that the platysma myoides gives the expression of pain ; and when united with the frontal muscle, it expresses terror; if with the pyramidalis, then there is rage. The electro-contraction of the triangularis nasi gives the vo- luptuous expression ; while that of the zygomaticus major always yields those expressions of mirth from the slightest twinkle of a roguish smile to the most extravagant laugh ; and if this is united with the frontalis, there is then a modification to the agreeable surprise; but if with the platysma myoides, there is the re- strained, " can't-help-it" or threatening laughter. The contrac- tion of the zygomaticus minor, on the contrary, gives the mel- ancholy air to the countenance ; and the levator alaque nasi, with the labii superioris, are the crying muscles, that in children pro- duce such an ugly grimace. The levator menti is the only muscle in action when one mutters or repeats in audible prayers, as is done in Roman Catholic churches. It is by the contraction of the external fibres of the orbicularis oris that the lips are protruded, as for pouting, kissing, and whistling; while the in- ternal fibres press the lips against the teeth. Then the contrac- tion of the triangularis oris gives the deeper expressions of sadness. In children it is seen in play as the precursor of tears; but in its maximum of action there is presented the striking expression of disgust.