The modern quacks detected : In three parts. I. Exposing their qualifications and remedies. II. Proving the insufficiency of the letter to answer what is proposed by them. III. Unfolding the nature and ill consequences thereof. Dedicated to the president of the Royal College of Physicians, in London. In which are exhibited, reasons why they ought to admit Dr. Schomberg a member of their learned and honourable body. By a London Physician.