SOUTHERN AFRICA. 25 
posed of these materials. The water was perfectly clear, and 
deposited not the smallest degree of any kind of sediment, 
neither in the pool where the springs were, nor by the edges of 
the stream. A green Conferva grew on the margin of both. 
No change of color was produced upon the plants and stones 
with which the water came in contact. With sulphuric acid 
it deposited no sediment, nor became in the least turbid, nor 
were blue vegetable colors at all affected by it. No impreg- 
nation of any kind was discoverable, in the smallest de- 
gree, by the taste. On the contrary, it is considered so 
pure that the family living near it generally emploj^ed it 
for dressing their victuals ; and all their linen and colored 
clothes were washed in it without sustaining any injury. 
The thermometer I had with me was graduated only to 
140°, to which point it ascended almost instantaneously. 
The temperature appeared to be very nearly that of boiling 
water. 
The duration of hot springs for ages without any consider- 
able variation in temperature, or in the quantity of water 
thrown out, is one of those secret operations of nature that has 
not as yet been satisfactorily explained, but which has baffled, 
at all times, the speculations of philosophers. The decompo- 
sition of pyritical matter, the slacking of lime, and the sub- 
terranean furnace, heated wdth combustible materials, have 
each had their advocates, but each when " weighed in the 
" balance has been found wanting." 
From the hot wells we crossed the Breede, or broad river, 
and entered a klocf on the opposite, or northern, side of the 
