184 
HINTS TO TRAVELLERS. 
Yellow Fever. 
This is a highly infectious disease, one attack of which usually pro¬ 
tects against a second. 
Incubation period, two to five days. 
Symptoms .—The onset of the disease is very sudden, the highest 
temperature being reached almost at once; then follows a period of 
remission or calm, the pulse becomes abnormally slow, and this stage 
is usually either succeeded by convalescence, or the symptoms become 
worse and the patient dies. Some of the symptoms much resemble 
malaria, but the rapidity of the onset, severe pain in the forehead, 
eyes, and loins, the early scantiness of the urine, the bright eyes, 
the narrow red tongue, and the absence of pain about the spleen are 
characteristic. 
There is considerable thirst and vomiting, and in bad cases the vomit 
becomes black, the colour being due to the presence of blood. (In 
ordinary malaria the vomit is yellow, or in severe cases, such as black- 
water fever, it may be of bright or dark green colour.) In yellow fever, 
jaundice is developed about the third day, whilst in black water fever it 
comes on very early and soon begins to abate. 
Treatment .—Isolate the patient, open the bowels well by means of 
calomel, six grains, followed by a saline purge and hot-water enema. 
Give ten grains of bicarbonate of soda three times a day. Give cooling 
drinks such as fruit salt. Make the skin act. Apply hot fomentations 
to the back and mustard leaves to the pit of the stomach. 
Burn or thoroughly disinfect all discharges and clothing; boil all cups, 
spoons, etc., which the patient has used. 
Plague— (Bubonic plague.) 
A disease characterised by high fever and delirium, accompanied by the 
formation of glandular swellings in armpit, groin, or neck. 
Causes .—Bubonic plague is contagious from man to man; the infection 
may be carried by rats, soil or water, or the germs may gain an entrance 
to the body through a *cut or abrasion. The chief predisposing causes 
of plague are filth, overcrowding, bad ventilation and drainage, and 
