INTRODUCTION. xa 
a journal, in which will be recorded such remarks as he may think worthy, on 
the localities, the particularities, and the distinguishing characters and uses to 
which plants or minerals are applied, you will afford him such assistance with 
regard to the latitude and longitude of particular places, as he may require, in 
order that no information may be wanting, on points generally interesting to 
science. 
And as the parts of fructification of trees, in warm climates, are seldom ac- 
cessible to botanists, on account of the labour of felling them, and consequent, 
the arborescent plants of these climates are least of all known, you will allow 
one or two of the carpenters to accompany the Professor and Gardener, to ena- 
ble them, by felling trees of a moderate size, to get at the flowers and fruits 
of those species of which it may be deemed advisable to collect and preserve 
specimens. 
Though Mr. Smith modestly declines to take upon himself the office of Pro- 
fessional Geologist, yet, having examined the Canary Islands, in company with 
his friend the Baron Von Buch, who eminently excels in that interesting 
science, there can be no doubt of his sufficient proficiency in that branch of 
physical knowledge, to enable him to collect such specimens as may be useful to 
elucidate the geology of those parts of southern Africa, through which you may 
have to pass. 
To enable you however, and any of the gentlemen who accompany you, to 
form a competent knowledge of what may be desirable to bring home from the 
mineral kingdom, afew general directions may be of use. 
The objects of the most value, are the metallic ores, fossil bones, teeth, 
shells, impressions of plants and fishes ; those of least esteem, spar, crystal, py- 
rites, pieces of loose stone or gravel, unless where the last is supposed to contain 
metallic matter. 
The most common substances, (such as flint, chalk, sandstone, coal, clay, 
limestone, basalt, slate, granite) will be interesting, if Jabelled on the spot, and 
kept clean, in separate papers, and not suffered to rub against each other; the 
label to express the name and situation of the rock or mountain, from which 
the specimen was detached. The size of a common watch is sufficiently large 
for each specimen ; shape is of little consequence ; that of a cube split in two is 
perhaps the most conyenient. 
Specimens of rock are always desirable, with the native names for each, 
where they can be obtained; and the uses to which they are applied. 
Fossil bones and shells, of whatever size, should be brought away entire; if 
an entire skeleton be found it should be brought away ; and it is essential to 
