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of all is the power of choosing in what part of the body, the variolous matter shall enter. In the natural small-pox, the contagion is most commonly taken into the stomach, in deglutition, or apply'd immediately to the brain and lungs by respiration, organs of the most delicate kind, and whose actions are most essential to life; here the variolous matter by exerting its whole undiminished force, acts with all the energy of its poisonous quality, to injure the blood and nerves, and produces the most fatal effects, whilst in the other way, being received in a very small quantity, by a very slight incision in the skin, it must pass through the lymphatic vessels and glands, which serve as strainers, and which do not suffer it to enter the blood, without being first diluted with lymph in its course to them, through the vessels of absorption, which convey the smallest portion of it, mixed with a very great proportion of lymph, and therefore in a vastly weakened state, first to the glands, and from thence to the blood itself.
In respect to the choice of matter for inoculation, the principle circumstance to be attended to, is that it ought to be taken from a patient who has the large distinct kind, before the decline of the disease, and that is free from every contagious disorder.
From these circumstances which incontestably prove the great benefits arising from inoculation, being now well known and established, the prac-
