December 7th.—Returned from Jeypore, whither I had been to report on the Caoutchouc trees. [{193}]
These trees appear to be limited to the belt of jungle or toorai which commences towards the foot of the Aka and Duphla hills, and which in the part in which I examined them is about 8 miles wide. They are said to be found likewise among the neighbouring villages, but I saw no instance of this. They occur solitarily, or at most in groups of two or three. They appear to be more frequent towards the immediate base of the hills, and to prefer the drier parts of those humid and dense forests called toorai. They are frequently of vast size, and by this as well as their dense head, may be at once recognised even at a distance of a few miles. Some idea of their size may be formed from the following measurements of a large one:
Circumference of main trunk, 74 feet
Ditto, including the supports, 120 “
Ditto, of space covered by crown branches, 620 “
Height, ditto ditto, 80 to 100 “
The roots spread out in every direction on reaching the ground; the larger running along the surface, their upper portion being uncovered: occasionally they assume the form of buttresses, but never to such a marked degree as occurs in some other trees, such as the Simool, Herietiera, etc. The supports are only thrown out towards the base of the principal branches, not as in the banian at indefinite distances. The trunk is a compound one, formed entirely by the mutual cohesion of roots; not as in almost all other trees by the growth of parts in an ascending direction. Its aspect is picturesque and varied, occasionally putting on the appearance of sculpture. It is, I think, doubtful whether this as well as some other species of the genus are not to be considered as genuine parasites, at any rate they generally cause the destruction of the tree on which they originally grew. If this be the case the parasitism is the reverse of that which occurs in Cuscuta, in which the plantule draws its first nourishment from the earth, relinquishing this when sufficiently developed to enable it to draw its supply from other plants. I may here observe, that parasites are common on the peepul, contrary to the statement of M. DeCandolle.
The destruction of the foster-mother takes place by the mutual interlacement of the roots, which descending irregularly, form at first a strong net-work, subsequently becoming a cylindric binding, in the strongest possible way to the trunk, and preventing all lateral distinction. The hollow occupied by the trunk when dead may become filled up, when this has passed away, by other roots. The adhesion of the roots commences by abrasion of the bark, the union subsequently becomes of the most intimate kind. The supports are perfectly cylindrical; they become conical only towards the earth, on approaching which they divide into roots: they are strictly descending growths, and as such, under ordinary circumstances, they never produce leaves, etc. Roots likewise issue from every section of the bark of sufficient depth to reach the outer layer of wood, with the outer fibres of which they are obviously continuous. To such an extent is this carried, that transverse sections of young supports assume the appearance of coarse paint-brushes or tails. The lenticells, which are very numerous, have nothing whatever to do with their production; if the bark remains entire, no roots are thrown out except by division of the apex. The branches ascend obliquely, the outermost running nearly horizontally.
The juice is obtained from the larger; that from young parts is less thick: an exposed semi-denuded root, is selected for transverse incisions through the bark, from which alone the juice flows, a small hole is made in the ground immediately beneath the incised parts into which a leaf, generally of Phrynium capitatum is placed: it is collected in this simple manner in a very clean state, far more so than that which can be collected from the tree in any other situation. On issuing, it is of a very rich pure white; if good, of the consistence of cream: its excellence is known by the degree of consistence, and by the quantity of caoutchouc it contains. This is ascertained by rubbing a few drops up in the palm of the hand, which causes the watery juice to separate (probably by evaporation) from the caoutchouc which remains in the form of small, oblong, or round portions; and by kneading this in the hand, and striking it sharply once or twice with the fist it acquires elasticity, so that an additional test of excellence is at once pointed out. Many incisions are made in one tree, the juice flows rapidly at first, at the rate of sixty drops a minute from an ordinary incision, but this soon becomes so much diminished that it dwindles to eight. The bleeding is continued for two or three days, when it ceases spontaneously by the formation of a layer of caoutchouc over the wound; and it is to the commencement of this that the rapid diminution in the number of drops is perhaps to be attributed. The quantity obtained from one tree has not exactly been ascertained; by some it is stated to be as much as four or five maunds, while others say that a moderate tree will only yield one gurrah full, or about ten seers. From the slowness with which it flows, I should consider half a maund to be a fair average for each bleeding. The juice is, however, said to flow faster at night, but this demands verification.
The operation is repeated at the end of eighteen or twenty days. In seven miles of jungle we observed eighty trees, by far the greater portion of which were of large size. Lieutenant Vetch has made a calculation, (on the assumption that they are equally plentiful throughout Chardowar,) that the number in this district alone is --- trees.
I calculate the number to be about 20,000. There is no reason for supposing that they are not equally abundant throughout Noadwar, nor in fact on any line where toorai prevails between Goalpara and Bishnath; beyond this, however, the increase in latitude may occasion their decrease both in number and size. On the southern side of the valley there is every reason to believe it to be equally common. The general geographic range may hence be said to be in latitude 24°, to 26½° in longitude. It has been stated by Mr. Royle that it does not extend beyond Pundua, Jynteapoor, and Churra Punjee, but on no other authority than that it had not been found elsewhere.
Taking the number of trees at 20,000, and the produce of each from four bleedings at two maunds, the annual supply that may be obtained from Durrung may be estimated at 13,000 maunds of the caoutchouc itself, assuming Dr. Roxburgh’s proportion of one to three to be nearly correct. Some idea may be formed of the extent to which it is procurable, when from the mere outskirts of the forest, 300 maunds of juice may be collected in one month.
On the excellence of the Assam product as compared with that of America, it does not become me to pronounce. If strength, elasticity, clearness, and perfect freedom from viscidity, be tests of excellence, then this product may be considered as equal to any other. It has been pronounced by persons in Calcutta to be excellent, but no details have been entered into except by Mr. Bell, who objects to its snapping: if by this we are to understand snapping on being pulled too much, in contradistinction to breaking, it only proves its excellence. It is declared to be inferior to the American by Mr. McCosh, evidently on examination of the worst possible specimens.