Book I CONTAGION 47

cause they do not adhere and agglutinate on account of their
dryness. But fevers that have a foul and confined putrefac—
tion produce germs suitable for conveying contagions. I call
a putrefaction ïfoul', in which the putrefaction and the evapora—
tion of what putrefies are not superficial, but deep and affect—
ing the whole organism. I eall a putrefaction 'confined', in
which the particles that evaporate do not issue forth and are
not exhaled, but, somehow confined, are well and long shaken
and mingled; but they have also viscosity, for thus a strong
and glutinous combination is produced. The term  'mild?
seems to apply to contagious diseases, principally contagious
fevers, in which there is deep putrefaction from which much
moisture evaporates; this both induces viscosity and blunts
the keenness. In fevers where the acuteness is great, and great
heat is felt, the superficial particles evaporate hot and dry, for
which reason they are not contagious.