The surgeons assistant. In which is plainly discovered the true origin of most diseases : Treating particularly of the plague, French pox, leprosie, &c. of the biting of mad dogs, and other venemous creatures. Also a compleat treatise of cancers and gangreens. With an enquiry whether they have any alliance with contagious diseases. Their most easie, and speedy method of cure. With diverse approved receipts. By John Browne, sworn surgeon in ordinary to his late most excellent Majesty King William III. and late senior surgeon of St Thomas Hospital in Southwark.