(St.). St. Vitus's dance, once widely prevalent in Germany and the Low Countries, was a “dancing mania.” So called from the supposed power of St. Vitus over nervous and hysterical affections.
At Strasbourg hundreds of folk began To dance and leap, both maid and man; In open market, lane, or street, They skipped along, nor cared to eat, Until their plague had ceased to fright us. 'Twas called the dance of holy Vitus.
Jan of Konigshaven (an old Cerman $$$).
St. Vitus's Dance. A description of the jumping procession on Whit-Tuesday to a chapel in Ulm dedicated to St. Vitus, is given in Notes and Queries, September, 1856. (See Tarantism.)
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894