SOUTHERN AFRICA. 79 
fria'ole clay, and the interior surface was coated over with a 
black glassy pelhcle. The smell given out was at first slightly 
sulphureous and afterwards bituminous. Great quantities of a 
dark, red, ochraceous earth was thrown out from the bog in 
small heaps like mole-hills. This when taken between the 
fingers became oily and adhesive, and the color brightened 
to that of vermilion. Both the red, the green, and the yel- 
low substances, when boile^l in water, deposited a smooth 
clayey sediment, unctuous to the feel, tastless and colorless. 
The water had imbibed a strong acid, and had dissolved part 
of the copper kettle in which it was boiled, as appeared by 
this metal being brought down on pieces of polished iron. 
The impregnated water changed the color of blue paper. 
The want of chemical tests prevented any farther experi- 
ments; but I imagine the substances were sulphuric acid in 
combination with clay forming alum, and the same acid in 
union with iron, composing green vitriol or copperas, which 
the mixture of bituminous or other heterogeneous matter had 
prever\ted from forming itself mto regular crystals. 
The water of the spring was of the same temperature as the 
surrounding atmosphere ; but a farmer who was with us as- 
serted positively that fifteen years ago, when last he was on the 
spot, the water was thrown out warm to a considerable 
degree. His assertion, however, was liable to some doubt. 
Periodical hot springs are phenomena in nature not fre- 
quently, if ever, met with. It is just possible that a portion 
of unsatm'ated sulphuric acid coming in its disengaged state 
in contact with the water might occasionally raise its tempe- 
rature ; but the information of the peasantry on any subject. 
