There are several Plants which have a sleeping Property, though not in so great a Degree as the inspissated Juice of the Poppy, yet more poisonous, because they are not endued with that volatile Power to carry themselves off. Thus we find the Juice of Hemlock, Mandrake, Nightshade, and several others of this Class, loaded with an acrid Salt, which, when inwardly taken, will corrode, vellicate, and cause an immediate Inflammation in the Primæ Viæ, to which the Nerves consent by a general Convulsion; and if any of these venene Powers remain long enough in the Body, to insinuate themselves into the Circulation, the debilitated Blood will become stagnant in, or lacerate, the capillary Vessels. Examples of these have been seen in _Indians_, who have taken Poison, which, though not of immediate Power to destroy Life, has manifested itself in Ulcers over the whole Body; and what is related of the Poison of the Seps Hæmorrhous, or Hæmorrhoid Serpent, is very extraordinary, that it will make the Blood flow out from several Parts of the Body; which can only be accounted for by an extream Fluidity of the Blood, and a consequent Velocity in Circulation, increased to such a Degree, as to lacerate the capillary Vessels, and thereby force them to part with their Contents. From the various and violent Effects I have observed to arise from the Use of different Parcels of Opium, I am inclined to think, that the Juice of some Narcotic Plant is frequently added to that of the Poppy, in order to increase the Quantity of the Drug; and _Bellonius_ observes, that Traders in Opium have so far adulterated it, that four Ounces of the pure Drug have sometimes been multiplied to a Pound. I myself have observed, in the Use of two different Opiums upon one Subject, that the one had a mild and proper Effect, and the other, through its Churlishness of Operation in the first Passages and Symptoms, on the following Day, had the Appearance of Poison, though in an inferior Degree. Such may always be suspected of Adulteration with the acrid Juice of some other Plant, and when a Purging ensues the taking of Opium, it most probably arises from a Mixture with the milky Juice of _Spurge_; there being nothing in the Principles or Effects of the pure Drug, to excite Purgation. This I apprehend to be the Reason why solid Opium sometimes purges, and the Tincture very seldom, the Menstruum used, dissolving only the finer Powers. To judge of pure Opium in the Lump, is a great Nicety, and what the Buyer ought to be very careful of, that it may answer his Intention of easing, and not injuring his Patient, if he designs using it inwardly; for this Intent, some Authors have given Instructions; but how few are they, who are assiduous to know the different Degrees of Strength each different Lump may contain! It is thought enough, if it has the Appearance of Opium, and the stronger it is in Smell and Taste (provided it is not drossy) they think it will go furthest, and consequently is best.