212 A YELLOW DYE. — SUCCULENT PLANTS. 15, 16 July, 
strong, sharp thorns, so rigid and pungent, that no animal could 
graze near it; nor would the naked-legged Hottentots venture to 
walk amongst it, although it was not more than a foot and a half 
high. 
My men pointed out to me a small shrub *, the flowers of which 
they use as a dye for giving a yellow color to the leather of their 
preparing. By experiment, I found that the coroll(E of the dried 
flowers, being infused in a small quantity of warm water, gave out 
very readily a strong color, approaching to what is called Raw Terra 
di Sienna, but brighter. Being a vegetable color, it possesses the ad- 
vantage of flowing freely from the pencil or pen, and might be used 
as a very pleasing yellow ink. Some trials which I then made, have 
remained ten years, without fading or losing any of their original 
brightness. A permanent vegetable color of this quality would, per- 
haps, be useful in the arts ; and the collection of it might be a source 
of advantage, the more profitable, as being derived from land at pre- 
sent useless to man. Some other plants of the same natural order, 
which I afterwards met with, afford a dye equally good. 
A great variety of succulent plants grow in every part of the 
Karro ; and I exceedingly regret that I had neither opportunity 
for preserving them, nor time for making drawings. An object 
very desirable for botany, would be obtained, if a good draughts- 
man were to pass three or four years in travelling about the Cape 
colony, with the sole view of drawing, on their native spot, all those 
plants (excepting such as have already been figured and published) 
which, from their fleshy nature or delicate substance, cannot well 
be preserved in an herbarium. He would, by doing this, accom- 
plish a work of great utility, and one which, from the singular 
forms, or the delicate and beautiful flowers of the objects, could not 
fail to interest every lover of nature. No one, who has not ex- 
amined this country, can form any correct idea of the immense 
number and variety of plants of the succulent tribe, that are dis- 
* Catal. Geogr. No. 1208. Ex ordine Thymelearum. 
