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has juft recovered, is demonftrable from a 
well-known fabt, viz. that he is capable 
of infebting other people by his breath, 
fweat, or even by fimple contabL An¬ 
other obfervation, not lefs in point, is, that 
perfons lately recovered from an infectious 
difeafe, may, without rilk of being at¬ 
tacked by it a fecond time, live with, and 
attend upon others ftill labouring under its 
influence. 
Relapfes are in general owing to fome 
irregularity in the patient’s mode of life, 
or to fome violent affebtion of the mind, 
and happen during conyalefcence, when 
the nervous fyftem is not re-eftablifhed in 
its natural ftate. 
When the fyftem is once thoroughly re- 
eftablifhed, the fame difeafe is not eafily 
reproduced. Sometimes, even it does not 
again attack during the whole courfe of 
life, having left the living folid in a ftate 
incapable of receiving any impreflion of 
this 
