ERUPTIVE FEVERS. 159 



avoiding such concurrence may often, in the meanwhile, leave 

 persons exposed to the common infection, it merits inquiry, 

 whether every diseased state should restrain from the practice 

 of inoculation, or what are the particular diseases that should 

 do so. This is not yet sufficiently ascertained by observation ; 

 and we have frequently remarked, that the smallpox have often 

 occurred with a diseased state of the body, without being there- 

 by rendered more violent. In particular, we have observed, 

 that a scrofulous habit, or even the presence of scrofula, did 

 not render the smallpox more violent ; and we have observed 

 also, that several diseases of the skin are equally innocent. I 

 am of opinion, that they are the diseases of the febrile kind, or 

 ailments ready to induce or aggravate a febrile state, that espe- 

 cially give the concurrence which is most dangerous with the 

 smallpox. I dare not attempt any general rules ; but I am 

 disposed to maintain, that, though a person be in a diseased 

 state, if that state be of uncertain nature and effect, and at the 

 same time the smallpox be exceedingly rife, so as to render it 

 extremely difficult to guard against the common infection, it 

 will always be safer to give the smallpox by inoculation, than to 

 leave the person to take them by the common infection. 



DCVI. Though inoculation has been practised with safety 

 upon persons of all ages ; yet, from what has actually occurred 

 in the cases of common infection, and from several other con- 

 siderations, there is reason to conclude, that adults are more li- 

 able to a violent disease than persons of younger years. At 

 the same time, it is observed, that children, in the time of their 

 first dentition, are liable, from this irritation, to have the small- 

 pox rendered more violent ; and that infants, before the time of 

 dentition, upon receiving the contagion of the smallpox, are 

 liable to be affected with epileptic fits, which frequently prove 

 fatal. It is, therefore, upon the whole, evident, that, though 

 circumstances may admit, and even render inoculation at any 

 age proper ; yet, for the most part, it will be still more advisable 

 to choose persons at an age, after the first dentition is over, and 

 before the time of puberty. 



DC VI I. Though inoculation has been practised with safety 

 at every season of the year ; yet, as it is certain that the cold 

 of winter may increase the inflammatory, and the heats of sum- 



