of peftikntial Vifeafes] 25: Perfbn, and inducing ftill one common Di£ eafe ; thefe Particles are generally called by Phyiical Writers /W^t*, Contagiofa, or Con- tagij Seminia and the Difference of PefK- lences arifing from thefe Caufes feems much to differ from what have been hitherto ta- ken Notice of* as the former cannot be fhun- ned but by quite leaving the difeafed Cli- mate, or by fuch a Strength, or Turn of Conftitution, as refifts, or yields not to the general Diforder ; whereas in this laft Cafe* a Perfon feems to be equally fate in any Air that is not impregnated with thefe conta- gious Effluvia, and the greater!. Danger arifes from the Nearnefs to difeafed Peribns, or whatfoever elfe is capable of harbouring thole mifchievous and fecret MeiTengers, as the Poet (a) takes Notice. Quo frofrior quifq eft, fervitq) fdelius agro In fartem Let hi citius venit. — <— • THE Hifcories of Phyfick abound with Relations of PefHlences from no other Caufe than what arifes from the Importation of the Difeafe, if it may be fo termed, from diftant (a) Ovid. Meram. lib. 7,
