456 Proceedings of the Royal Physical Society. 
dry climate, the humidity being about 55 per cent. During 
the six hottest months of the year the average maximum 
temperature is 82° F., the average minimum temperature 
55° F. The dust-storms are the only drawback to this 
climate. The average maximum temperature for the six 
coldest months is 66° F. The rainfall is 16 inches. 
Diseases of the chest are very rare in this district, and it 
forms an admirable health resort for phthisical patients. 
Dysentery and diarrheea are the chief diseases to be dreaded 
here. 
The Transvaal has the same altitude as the Orange Free 
State, and possesses groups of mountains. It also has a 
dry climate, which is salubrious and exhilarating. The 
rainy season lasts from October to March, with an average 
rainfall of 30°74 inches. The principal diseases in this 
district are typhoid fever, dysentery, and diarrhcea. Leprosy 
and diphtheria are also. met with; the occurrence of 
malaria is unimportant. Owing to sudden changes in the 
temperature, bronchial catarrh is fairly common. Phthisis 
is not seen. 
In Natal, including Zululand, Basutoland, Griqualand East, 
and Pondoland, the climate in this region varies consider- 
ably. At Durban, on the coast, the mean annual temperature 
is 77° F., the mean range 18° F., the rainfall is 33 inches. 
At Pietermaritzburg and the interior, the mean annual 
temperature is 68° F., but the sudden changes from hot, dry 
land winds to moist sea breezes are trying. July to Septem- 
ber are the most trying months in Natal. The rainfall at 
Pietermaritzburg is 31°87 inches. With the exception of 
isolated areas at the coast, and in some of the gullies in 
Zululand, malaria is practically unknown, but typhoid fever 
and dysentery are fairly common, as also is diarrhcea in 
the hot season. Respiratory diseases are very rare, but 
diphtheria, small-pox, measles, and scarlet fever sometimes 
occur in epidemics. Phthisis, except in imported cases, is 
practically unknown. 
Cape Colony is, on the whole, very healthy. Temperature 
and rainfall vary in different places. At Cape Town itself 
the mean annual temperature is 67° F., the annual range 
