ria, as well as tonsillitis and aphtha, are enumerated amongst the
diseases of external membranes, because they are exposed either to the
atmospheric air, which is breathed, and swallowed with our food and saliva;
or they are exposed to the inflammable air; or hydrogen, which is generated
in the intestines; both which contribute to produce or promote the
contagious quality of these fluids; as mentioned in Class II. 1. 5.

It is not speaking accurate language, if we say, that in the diseases of
this genus the fever is contagious; since it is the material produced by
the external membranes, which is contagious, after it has been exposed to
air; while the fever is the consequence of this contagious matter, and not
the cause of it. As appears from the inoculated small-pox, in which the
fever does not commence, till after suppuration has taken place in the
inoculated arm, and from the diseases of the fifth genus of this order,
where contagion exists without fever. See Class II. 1. 5. and II. 1. 3. 18.

SPECIES.

1. _Febris sensitiva inirritata._ Sensitive inirritated fever. Typhus
gravior. Putrid malignant fever. Jail fever. The immediate cause of this
disease is the increase of the sensorial power of sensation, joined with
the decrease of the sensorial power of irritation; that is, it consists in
the febris sensitiva joined with the febris inirritativa of Class I. 2. 1.
1. as the febris sensitiva irritata of the preceding genus consists of the
febris sensitiva joined with the febris irritativa of Class I. 1. 1. 1. In
both which the word irritata, and inirritata, are designed to express more
or less irritation than the natural quantity; and the same when applied to
some of the diseases of this genus.

This fever is frequently accompanied with topical inflammation, which is
liable, if the arterial strength is not supported, to end in sphacelus; and
as mortified parts, such as sloughs of the throat, if they adhere to living
parts, soon become putrid from the warmth and moisture of their situation;
these fevers have been termed putrid, and have been thought to owe their
cause to what is only their consequence. In hot climates this fever is
frequently induced by the exhalations of stagnating lakes or marshes, which
abound with animal substances; but which in colder countries produce fevers
with debility only, as the quartan ague, without inflammation.

The sensitive inirritated, or malignant, fever is also frequently produced