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in the centre, the eyes dull, heavy, and suffused, the pulse quicker, 
the thirst more urgent, the skin more dry and warm, and the mind 
disturbed. On the sixth day the eruption becomes more general 
and distinct, like rubeola, occasionally fading or disappearing sud¬ 
denly, and becoming as the disease advances flattened and of a 
darker or duskier hue; and when the fever is accompanied with con¬ 
gestion of the brain or lungs, or by thickening of the lining mem¬ 
brane of the bronchial vessels, it assumes that livid appearance 
usually called petechia. This eruption, when slight, frequently dis¬ 
appears in a few days, but more frequently is visible during the 
whole course of the disease. 
6th. That simple unmixed contagious typhus usually continues 
for fourteen days from the first attack, when the febrile symptoms 
abate, the eye becomes clearer, the skin softer, and the mind com¬ 
posed, with less thirst; there is sometimes a slight abatement of the 
symptoms on the tenth day, particularly in children, at times nearly 
complete. 
7th. That when the febrile symptoms continue beyond the fifteenth 
day without abatement, local lesions exist, to which must be attri¬ 
buted the longer continuance of the febrile symptoms. The appe¬ 
tite frequently continues defective till the twenty-first day, when all 
the functions resume their healthy action. 
8th. That contagious typhus is often to be met with in combina¬ 
tion with other diseases, usually of a local character, as of the 
lungs, the mucous membrane of the stomach and intestines, more 
particularly the aggregated glands of the ilium, or the membranes of 
the brain. 
9th. That by the local diseased action of the parts above men¬ 
tioned, the febrile action of the system is kept up; but the character 
of the disease is changed ; and in such cases it frequently goes on 
to a fatal termination, or abates upon the twenty-first day from the 
commencement of the disease. 
10th. That between the ages of seven and fifty, nineteen out of 
twenty are susceptible of being affected by contagious typhus if ex¬ 
posed to the contagion, and not protected by having previously had 
the disease; but that children under five years are rarely affected 
with contagious typhus, and under two may continue to suckle or 
sleep with the mother labouring under typhus without catching the 
disease. 
11th. That contagious typhus is an exanthematous disease, and, 
like smallpox, measles, and scarlet-fever, during its course produces 
some change on the system, by which the individual having once 
undergone the disease, is (as a general rule) secured against a se¬ 
cond attack, and may with impunity expose himself to the conta¬ 
gion of typhus, if he continue to reside in the same country in 
which he previously had the disease. 
12th. That contagious typhus never exists in combination with 
any of the exanthematous diseases. 
13th. That in every case of pure typhus the blood undergoes 
during the disease a considerable change, becoming darker in co- 
