INTRODUCTION. xxxix 



a journal, in wliich will be recorded such remarks as he may think wortliy, on 

 the locahties, the particularities, and the distinguishing characters and uses to 

 ^hich 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 consequently 

 the arborescent plants of these chmates ai-e 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, a few 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 labelled 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 spUt in two is 

 perhaps the most convenient. 



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 



