Any description of the outbreaks of venereal disease is of necessity bound up with the migration of races, or parts of races, with wars and the consequent dislocation of the social system resulting from them. There are many inferences available from current writers showing how this contagious disease was spread and there is a good deal of reason to believe that some, at least, of the numerous cases of “leprosy” for which provision was made on frequent trade routes in past times were really cases of venereal disease.