A treatise of the small-pox and measles [electronic resource] : describing their nature, causes, and signs, diagnostick and prognostick, in a different way to what hath hitherto been known : together, with the method of curing the said distempers, and all, or most, of the best remedies : also, a particular discourse of opium, diacodium, and other sleeping medicines : with a reference to a very great case / by Gideon Harvey ..