The face here does the office of a dial-plate, and the wheels and springs, inside the machine, putting its muscles in motion, shew what is next to be expected from the striking part. Not that the motion of the spirits is continued all the way by the impression of the object, as the impression may terminate in the substance of the brain, the common fund of the spirits; the rest Dr. Gurther imagines, may be effected much after the same manner as air is conveyed into the pipes of an organ, which being uncovered, the air rushes in; and when the keys are let go, is stopped again. Now, if by repeated acts, or the frequent entertaining of a private passion or vice, which natural temperament has hurried, or custom dragged on to, the face is often put in that posture which attends such acts; the animal spirits will make such passages through the nerves, (in which the essence of a habit consists,) that the face is sometimes unalterably set in that posture, (as the Indian religious are by a long continued sitting in strange postures in their pagods,) or, at least, it falls, insensibly and mechanically, into that posture, unless some present object distort it therefrom, or some dissimulation hide it. This reason is confirmed by observation: thus we see great drinkers with eyes generally set towards the nose; the abducent muscles (by some called bibatorii, or bibatory muscles,) being often employed to put them in that posture, in order to view their beloved liquor in the glass, at the time of drinking. Thus, also, lascivious persons are remarkable for the _oculorum mobilis petulantia_, as Petronius calls it. Hence also we may account for the Quaker’s expecting face, waiting the spirit to move him; the melancholy face of most sectaries; the studious face of men of great application of mind; revengeful and bloody men, like executioners in the act; and though silence in a sort may awhile pass for wisdom, yet sooner or later, St. Martin peeps through the disguise to undo all. “A _changeable face_,” continues Dr. Gurther, “I have observed to show a _changeable mind_, but I would by no means have what has been said be understood as without exception; for I doubt not but sometimes there are found men with great and virtuous souls under very unpromising outsides.” “Were our observations a little more strict and delicate, we might, doubtless, not only distinguish habits and tempers, but also professions. In effect, does there need much penetration to distinguish the fierce looks of the veteran soldier, the contentious look of the practised pleader, the solemn look of the minister of state, or many others of the like kind?” A very remarkable physiological anecdote has been given by De La Place, in his “_Pièces Interrestantes et peu connues_.” Vol. iv. p. 8.