HEALTH AND DISEASE 311 



pegmatite, and aplite. The plateau continues to 

 slope to the east towards the Zambezi in a 

 formation of sandstone and limestone inter- 

 sected by numerous alluvial river belts. 



To the south the plateau stretches through 

 arid sandy dunes and flats intersected by dry 

 watercourses (mulolas) and hollows (marembas) 

 till it merges into the deserts of south-west 

 Africa and the Kalahari. 



The climate in these eastern and south- 

 eastern plateaux is hot and enervating, especially 

 in the more wind-sheltered valleys, and owing to 

 malarial mosquitoes is unhealthy except in the 

 dry and cold months of the year from June to 

 September. The mean annual temperature in 

 the south of the colony is 75 with variations of 

 nearly 20, the rainfall 20 to 25 inches. In the 

 east and south-east a somewhat similar tem- 

 perature is accompanied by a heavier rainfall of 

 40 inches or more. 



The minerals found in these provinces are 

 sulphide of copper near Dombe, gold at Cassinga, 

 and petroleum along the coast. 



HeaHh and Disease. Angola may be divided 

 from this point of view into areas which are 

 tropical and subtropical, by latitude and climate, 

 and others in the highlands which are temperate 

 in spite of their latitude. There are indeed vast 

 areas in the plateaux which have a sunny yet 

 cool and bracing climate, more disease-free than 

 Europe itself, if care is taken to guard against the 

 rapid fall of temperature at night, and avoid chills. 



The white man should keep at least as fit in 



