1888 - 89 .] Dr R. W. Felkin on Tropical Diseases. 293 
Remarks . — Many have been the theories started to explain the 
cause of Beri-beri, but, owing to the limited well-defined areas in 
which the disease is endemic, most of them are unsatisfactory. 
Its epidemic spread, however, is probably influenced by climate, 
and seems to coincide with conditions of high atmospheric 
moisture and extreme thermometric variations. Some parasite will, 
doubtless, ere long, be proved to be the real cause of the disease, and 
it is probable that its production will be traced to the soil, for in 
those places where Beri-beri is endemic the soil abounds in saline 
materials, such as magnesia, lime, chlorides, alumina, and iron. 
Although all races and persons of all ages are attacked by Beri- 
beri, the dark races suffer most, and adult men far more than 
women and children. Indeed, so great is the disproportion between 
male and female sufferers, that the cases seen in women are about 
one to thirty-one in men. Although it is, as a rule, rare for 
children under fifteen to be attacked by Beri-beri, yet there are 
epidemics on record in which children seem to have suffered most. 
Whatever be the cause of Beri-beri, a residence of eight or ten 
months in an endemic area appears to be necessary before a person 
can be attacked by it, and it is also a remarkable fact that it 
attacks by preference persons in an apparently robust condition 
according to some authorities, others think debility a predisposing 
cause. 
VIII. Oriental Plague. 
(See Plate V. B.) 
Synon . — The Pest; Inguinal, Bubolic, Glandular, Oriental, 
Indian, Pali, and Levantine Plague; Oriental Typhus; Septic 
Pestilence ; Fr. La Peste ; Ger. Die Pest. 
Definition . — A specific fever, attended by bubo of the inguinal or 
other glands, and occasionally by carbuncles. 
Geographical Distribution . — In olden times Oriental Plague had 
a very wide distribution; now it is met with in much narrower 
limits, and it is to its present distribution that we refer. 
In Africa its area is distinctly limited to the northern coast belt, 
including Morocco, Algiers, Tunis, Tripoli, and Lower Egypt. In 
Egypt it has never gone beyond the first cataract of the Nile. In 
Russia it is met with in Astrakan along the Volga, and outbreaks 
