TARANT1SMUS is the name given to a peculiar nervous affection which was long supposed to be the consequence of the bite of the Tarantula Spider. It seems to hare occurred frequently in the king don of Naples during the I6th century, and to have been nearly similar in its characters to the disease which was originally called St. Vitus's dance [Cnonsal, and to that which has occasionally pre vailed in parts of Scotland, and has been called the "leaping ague.' The patients, nearly all of whom were women, soon after being bitten (as it was supposed) used to fall into a profound stupor, from which nothing roused them but the sound of such music as pleased them, on hearing which they had an irresistible desire to dance. So long as the music continued, and was in tune and sufficiently lively, they would go on jumping and dancing till they fell exhausted ; and, all the time, some used to shriek, some to laugh and sing, and some to weep. When, after a short rest, they had recovered from their fatigue, they would again begin to dance with as much vigour as before, unless the music were played slowly or confusedly, when they would stop and grow anxious and melancholy, or even, if the music were not soon made agreeable to them, would fall into a dangerous state of stupor. The disease used to last about fourslays, and seemed to be cured by the profuse perspiration brought on by the active exercise ; but it often returned at the same time in the following year, or even for a succession of years, and on every occasion required the same treat ment.
Since it has been found that the bite of the Tarantula can produce no such strange effects as these, many have suspected that the disease ascribed to it never really existed, but was feigned for the purpose of exciting pity or for the pleasure of dancing. There is good reason to believe that in most instances it was counterfeited : but there can he no doubt that such a disease had occurred and had given occasion to the practice of the fraud. Besides its similarity to diseases whose reality is generally admitted, such as the St. Vitus's dance and the leaping-ague, cases have occasionally been met with in recent times which closely resemble it, and in which there could be no just suspicion of fraud. Such a case is described by Mr. K. Wood, in the seventh volume of the' Medico-Chirurgical Transactions ; ' another is recorded by Mr. Crichton, in the thirty-first voluine of the Edinburgh Medical and Surgical Journal ;' and in the Cyclopedia of Practical Medicine.' art. ' Chorea,' several cases of analogous affections are related. All these however occurred singly. That the Tarantismus and the St. Vitus's dance should have assumed the characters of epidemics may be ascribed to their propagating themselves, as all convulsive affections are apt to do among nervous and superstitious persons, by the pro pensity to imitation, the effects of which are still frequently seen in the production of hysteria, chorea, and similar diseases.