In all cases, when I take matter from an inoculated person, it is from the place where it was inserted; as I am always sure to find infection there if the disease succeeds, and always of sufficient energy. It may appear strange that no bandage, dressing, or application whatsoever, is made use of to the part infected; but that the most simple incision being made, and moistened with the smallest particle of the recent fluid matter, the whole is committed to nature. This method is however perfectly right, because the application of either plaister or unguent, as is the usual practice, will occasion an inflammation on some skins, and in all tend to disguise the natural appearance of the incision, and prevent our forming a proper judgment of the progress of the infection; which will afterwards appear to be a matter of much importance. If neither an inoculated patient is at hand, nor any one in the neighbourhood has a distinct kind of the natural disease, a thread may be used as in the common manner, provided the thread be very recently infected; but I think it ought to be used as soon as possible after being charged with infecting matter. The following method of introducing the disease has likewise been found effectual; but I have never practised it myself. Dip the point of a lancet in variolous matter; let it be held in the air till it is dry; after which it may be closed and kept in the common case without any further care; and with this prepared lancet raise the scarf skin obliquely, and keep the lancet a little time in motion between the two skins, that part of the matter may be mixed with the animal juices; then withdraw the lancet, and leave the incision uncovered as before. OF THE PROGRESS OF INFECTION. Hitherto very little regard seems to have been paid to the progress of infection discoverable by the part where the operation was performed. But it will appear in the sequel, that an attention to this circumstance is very necessary, because a just prognostic may thence be sometimes formed of the future state of the distemper, and indications may be taken from the different appearances on the arm, that will enable us to prevent inconveniencies. The former method of covering the place of incision with a plaister, and continuing upon it dressings of one sort or another, prevented much useful information of this kind. They prevented any judgment by the touch, and sometimes rendered that by the eye equivocal. The day after the operation is performed, though it takes effect, little alteration is discoverable. On the second day, if the part is viewed with a lens, there generally appears a kind of orange-coloured stain about the incision, and the surrounding skin seems to contract. At this time I usually give the following medicine at going to bed, either mixed with a little of any kind of jelly, or more frequently made into a pill. Calomel and compound powder of crabs claws, of each 3 grains, emetic tartar 1/10 of a grain.