particular dispositions should constantly, or mostly so at least, have a mild and safe smallpox; and he, who has the contrary dispositions, should have it dangerously, and often mortally.
To illustrate this: suppose it had been constantly observed that lean people had fewer and kinder small-pox than fat ones; these last might be prepared for inoculation, by lessening their fat, and reducing them by means of a strict diet to a state of leanness. It is, however, plain that, in order to attempt such a preparation, it must have been demonstrated from repeated experiments, that leanness is a favourable disposition for receiving the small pox with as little detriment as possible to health.
But if no observation has discovered that such or such disposition is more favourable than the contrary one to have the small-pox in the most harmless manner; if the observations made for 1100 years upon the natural, and for upwards of fifty upon the inoculated small-pox, leave us in that respect under the greatest uncertainty; what are we to think of preparations intended to procure particular dispositions, which no body knows with certainty to be more favourable than the contrary ones? Now this is by no means a supposition, but a fact, which every ingenuous physician will readily agree to.
We see this disorder severe or slight, dangerous or harmless, indiscriminately in strong or weak, lean or fat people; in constitutions
