B TRAVELS IN 
mistry have ascertained to be particularly favourable to the 
health and vigour of plants. 
There is neither a volcano nor a volcanic product in the 
southern extremity of Africa, at least in any of those parts 
where I have been, nor any substances that seem to have un- 
dergone the action of fire, except masses of iron-stone found 
generally among the boggy earth in the neighbourhood 
of some of the hot springs, and which appear like the scoriae 
of furnaces. Pieces of pumice-stone have been picked up on 
the shore of Robben Island, and on the coast near Algoa Bay, 
which must have been wafted thither by the waves, as the 
whole basis of this island is a hard and compact blue schistuSs 
with veins of quartz running through it, and that of the eastera 
coast iron-stone and granite. 
The climate of the Cape may be considered as not unfriendly 
to vegetation ; but by reason of its situation, within the influ- 
ence of a kind of Monsoon. or periodical winds, the rains are 
very unequal, descending in torrents during the cold season, 
whilst scarcely a shower falls to refresh the earth in the hot 
summer months, when the dry south-east winds prevail. 
These winds blast the foliage, blossom, and fruit, of all those 
trees that are not well sheltered from their baneful gusts, 
which, for about six months, almost constantly blow from 
that quarter- Nor is the human constitution better protected 
against the painful sensation of tlie south-east winds of the 
Cape than the plants. Like the south-east Sirocco of Naples 
they relax and fatigue both the body and mind, rendering 
ihcu] Uttterly incci])able of activity or energy. During their 
2 
