This noble tree, which is found throughout the United States, is so well known that it needs no description. It is the common white poplar of Maine and New Hampshire. Its qualities are, bitter, diuretic, and astringent--it is also a tonic, and somewhat stimulant. It is a first-rate article for indigestion, canker in the stomach, consumption, liver complaints; also in diarrheal affections and other complaints, occasioned by debility--acting as a universal tonic; restoring the tone of the organs, and producing a healthy action of the liver; creating an appetite, and giving strength and vigor to the whole system. Poplar bark is perhaps the most universally applicable tonic of Dr. Thomson's Materia Medica It possesses valuable febrifuge qualities, and on account of its diuretic qualities, it is a good article in gravel and dropsy. Dr. J. Young says, "I have prescribed the poplar bark in a variety of cases of intermittent fever, and can declare from experience that it is equally efficacious with the Peruvian bark, if properly administered. There is not," says he, "in all the Materia Medica, a more certain, speedy and effectual remedy in hysterics than the poplar bark." This, let it be remembered, is "regular" testimony. This article should be used in combination with other articles forming "bitters," after the system is cleansed with courses of medicine, and all morbific matter expelled--the system is then ready to receive medicines of a strengthening character. The mode of procuring the bark is to strip it from the tree, any time when the sap prevents it from adhering to the wood. The outer bark should be shaved off; the inner cut into strips and dried in the shade. The mode of administering it is to infuse it in water--an ounce of the bark to a pint of water, and give freely.