On another street in this city is another branch from the Upas tree. I do not wish to advertise for him, hence omit his _names_, which are legion. Two of them begin with the letter D. The true name of this impostor commences with an M. He is old enough to be better. I know of patients who have been fleeced by him without receiving the least benefit, when the knowledge necessary to prescribe for their recovery, or of so simple a case, might be possessed by even the office boy. You go to his first office and inquire for the first _alias_. The usher, a boy sometimes, takes you in, and, slipping out the back door, he calls the old doctor from the next office. They are not connected. Through a glass door he takes a survey of you, to assure himself that you have not been victimized by him already under his other _aliases_. If he so recognizes you, he summons a convenient "assistant" to personate the doctor, and thus you are robbed a second time. HISTORY OF A KNAVE. The following is a brief and true history of one of the vilest charlatans and impostors now practising in Boston. He has amassed a fortune within a few years by the most barefaced villanies ever resorted to by man. He is one of the most abominable charlatans, who, for the almighty dollar, would willingly sacrifice the lives of his unfortunate victims, who, by glowing newspaper statements and seductive promises, have been drawn into his murderous den. By the side of such unprincipled villains, the highwaymen, the Dick Turpins, with their "Stand and deliver!" or "Your money or your life!" are angels of mercy, for the former rob you of your last dollar, and either endanger your life by giving you useless drugs that check not the disease, or hasten your demise by poisonous compounds given at random, the virulent properties of which the vampires know but little and care less. Their boast that their remedies are "_purely vegetable_," "hence uninjurious", is as false as their pretensions to skill, and is counted for nothing when we know that vegetable poisons are more numerous, and often more rapid and violent in their action, than minerals. Both calomel and other minerals are often _given_ by these charlatans. I say _given_, for few of them know enough to write a legible prescription, much less to write the voluminous works which they put forth on "manhood," "physiology of woman," etc., which are but so many advertisements for their vile trade and criminal practices, and are intended to alarm and corrupt the young and unwary into whose hands they may unfortunately fall.