281 
1888 - 89 .] Dr R W. Felkin on Tropical Diseases. 
Dengue in persons suffering from, any surgical complaint. In 
Goojerat in 1824, and in Amoy in 1872, it was found that all the 
severe cases were limited to the native population, that the Euro- 
peans suffered to a far less extent, and that those who were attacked 
by the disease had it in a remarkably mild form. 
As to the specific nature of Dengue, there can be no doubt, but 
whether due to a parasite or not is at present unknown, nor is it 
yet ascertained whether the poison springs up de novo at all points 
where its potency is manifested, or whether it is only epidemic at a 
few places, and spreads from these under favouring circumstances. 
Ab first Dengue was not thought to be contagious, but it is both 
infectious and highly contagious, and the diffusion of the disease 
could be traced in the epidemic of 1871-73, in the East from port 
to port, and from country to country along the highways of land 
and water traffic. One attack of Dengue does not confer absolute 
immunity from subsequent attacks, although it does so to a 
certain extent. 
III. Asiatic Cholera. 
(See Plate III.) 
Synon . — Serous Cholera; Spasmodic Cholera; Malignant Cholera; 
Ft. Cholera asiatique ; Ger. Asiatische Cholera. 
Definition . — Asiatic cholera is a specific disease, characterised by 
violent vomiting, rice-water evacuations, cramps, prostration, 
collapse, and other striking symptoms ; tending to run a rapidly 
fatal course ; and capable of being communicated to persons other- 
wise in sound health, through the dejecta of patients suffering from 
the disease. 
Geographical Distribution . — With regard to the distribution of 
cholera, it is not advisable to proceed on exactly the same lines 
as with other diseases, for, although the epidemic area of cholera 
is very vast, its endemic area is very limited. It will be well 
therefore, in the first place, to specify those regions which have 
hitherto escaped the ravages of the disease, next to define its 
endemic area, and finally to make some general remarks as to its 
pandemic diffusion. A glance at the map will render this division 
clear. 
Up to the present time, Australia and the islands of the Pacific 
