Sedulously abstaining from the parade of erudite research or indulgence in speculations, however ingenious, it is our intention to describe with accuracy all that we saw; and if, in so doing, we shall be found repeating what others have said before us, and proposing inferences previously drawn, the observations and deductions are to be considered as not the less our own, since we only speak from conviction, founded on the evidence presented to our senses. Our opportunities for accurate judgment were most ample, being derived as well from an attendance of nine months on the hospital for the reception of the poor, labouring under the disease, as from one of us prescribing, during a part of the time, for the Philadelphia Dispensary, added to the cases furnished us by private practice, and very many others, the records of which have been kindly placed at our disposal by professional friends. The ravages committed by the small-pox in Baltimore, and the fact of many who had been previously vaccinated having been attacked by the disease during the years 1821 and 1822 were notorious to us all, but were productive of little alarm in Philadelphia. The non-appearance of the scourge in the greater part of the period, when the former city was suffering under it, justified, to a certain extent, this feeling of security, and seemed to call more on our sympathies for our neighbours than on our fears for ourselves. In the month of September, 1823, some cases of fever, with pustular eruption, first arrested the attention of the medical faculty, some of whom were, of course, called on to render professional assistance. The residence of some of the persons, thus attacked, in Water street, and their emigration from Europe, naturally induced a suspicion of this disease being no other than the small-pox, imported by, or brought in with them. Very nearly about the same time, however, some scattered cases of a similar eruptive disease, were noticed in the upper or western portion of the city, without our being able to trace any intercourse or connexion between these and the others in the lower or eastern part, viz. Water street.