912 REPORT OF THE HARVARD AFRICAN EXPEDITION 
Summary 
While travelling in Liberia and in the Belgian Congo with a party of seven 
or eight whites, the problem of supplying safe drinking water was ever present. 
Boiling and several methods of chlorinating were tried. Boiling was generally 
preferred when clear water was not available, because the turbid water neutral- 
ized a large amount of chlorine. 
For the purpose of chlorinating clear waters three methods of using calcium 
hypochlorite were tried. All were found unsatisfactory because of rapid deteri- 
oration of the calcium hypochlorite, even when packed in amber glass ampoules. 
Halazone, on the other hand, proved sufficiently stable for practical purposes 
— a fact of great importance for the traveller. 
Although the Expedition, numbering eight whites in Liberia and seven in the 
Belgian Congo, spent about a year in tropical Africa, no member of it contracted 
dysentery or suffered from severe intestinal diarrhoea. 
In parts of Africa during prolonged dry seasons the only water available may 
be excessively muddy. Under these circumstances Mr. Whipple’s recommenda- 
tions for clarification of water, as described above, would probably prove prac- 
tical and satisfactory. Few persons would have the patience to make use of 
more time-consuming procedures. If alum were used only when necessary, a few 
pounds would go a long way. Probably preliminary alkalinization of the water 
would seldom be necessary in Liberia or in the Belgian Congo. 
