ON THE COPAL OF ZANZIBAR. 
655 
There are three distinct kinds of Copal in the Zanzibar trade, subdivided by merchants 
into many classes, according to colour, form, surface, and other peculiarities known to 
those in the trade, and affecting the value variously in different markets:—first, we have 
“ Sardarusi-m’ti,” Tree-Copal; second, “ Chakazzi,” or Copal dug from the soil, but 
modern (seemingly) in origin, and obtaining a price like that of the former quality; the 
third is the true Sandarusi, like the second, dug from the soil, but hard, less soluble, 
and more than twice the value. This forms by far the greatest part of Zanzibar Copal, 
the export of which has sometimes reached 800,000 lbs. at a value of £60,000. 
I have already described the “Tree-Copal:” it is gathered directly from the tree, 
which is known along the coast from Mozambique to near Lamo, or from 3° to 15° 
south lat., but is most common between Cape Delgado and Mombas. The Trachylo¬ 
bium Mossambicense , Kl., is found along the creeks and on the maritime plain or the old 
sea-beach, but becomes very rare at a little distance inland, and quite unknown long 
before the change in geologic structure offers an explanation of its absence. It requires 
the near presence of the sea for its growth, and dies when far removed from its influ¬ 
ence. 
The second sort, or “ Chakazzi ” gum, is found in the ground at the roots of modern 
Copal-trees, or in the country where these exist; but it is also, I am told, to be got with 
true Copal. That it is found near the existing forests is certain; and there the true 
Copal is not known; and we must accept with caution the statement that it is also 
found in the interior, from this well-known fact, that our informants habitually mix the 
inferior coast-gum with the valuable produce of the interior. This “ Chakazzi ” is 
obviously the recent gum which has remained a short time in the soil after the death of 
the tree which produced it, yet long enough to take the impression of sand and stone, 
or other hard matter, as the hardest sealing-wax long left on a coin will take the im¬ 
pression, or as ice will flow down a valley. 
The Tree-Copal, or “ Anime” of the English markets, is undoubtedly the produce of 
forests now extinct; for there is no tree now growing at a distance from the coast which 
produces it. It is obtained all along the ancient sea-beach, the maritime plain which 
here fringes the Continent to a depth of 20-40 miles in general. Some spots are richer 
than others, and some soils indicate good “ diggings.” When the rains which follow the 
north-east monsoon have softened the soil, the natives of the country commence to dig 
this from small pits, searching the soil as removed; but there is no system, and, like the 
gold-washings of Africa, so the Copal-regions yield not a fraction of what a little system 
and industry might produce. At present every clan-feud stops the search. The pro¬ 
ducer receives, even when successful, only a trifle from the Indian merchants, who again 
part with it, often paying enormous dues to the Zanzibar State, to the European and 
American traders. The supply, considering the extent over which it is scattered, seems 
unlimited; for at present, with most inadequate means and much discouragement to the 
labourers, the amount obtained is very great. 
If we take into account the similarity of the recent and fossil resins in appearance, 
their near approach in physical properties, the fact that the recent gum, often being im¬ 
bedded in sand, takes the characteristic surface-markings, and recollect that where now 
the good Copal is dug as a fossil the present Copal-tree, in all probability, once grew, 
when the sea was nearer to the hills than now,—I think we may be satisfied that the 
Trachylobium was the source of the old Copal, which is the resin only modified by time 
and long exclusion from air and light under the ground. 
Perhaps it may be asked, Is there not proof in the gum itself that the Trachylobium 
then existed ? I have as yet found none: insects (all of them aerial) are often preserved; 
sometimes branches and leaves; but I have not seen evidence of the Copal-tree. When 
we remember that the resin soon hardens after being exuded, and that it runs from the 
underside of the main limbs, while the leaves, flowers, and fruit are at the extremities of 
the branches, we shall see that leaves of the underwood which sweep the lower branches 
are much more likely to be embalmed than the leaf of the tree itself, which, besides, is 
hairy, glossy, and unlikely to adhere. If a part of the modern tree were found in the 
old hard gum, the proof would be complete; at present some doubt remains. 
I have sent not only full herbarium specimens, but also specimens of the recent gum, 
of the “ Chakazzi,” and of the valuable Copal, in which are many insects; and I would 
suggest that entomologists should assist us by their opinions whether these belong to 
existing species or not.— The Journal of the Linnean Society. 
