GUTTA PERCHA, AIALAr, is the concrete juice of the Isonandra gutta, a forest tree of Penang, of the Malay Peninsula from Penang to Singapore, of Sumatm and of Borneo. It is called the Taban tree by the Malays of the Malacca, and in Borneo it is known by the name of Niato. The ch is pronounced like the ch in the English word perch. The tree grows slowly to from 60 to 70 feet high, and 3 or 4 feet in diameter. Its foliage is of a pale green on the upper side, and covered with reddish-brown hairs beneath ; it flourishes luxuriantly in alluvial tracts, at the foot of hills, and in such situations, in many places, forms the principal part of the jungle. The natives bad discovered its valuable properties before it became known to Europeans. They constructed from it whips, shoes, traces, buckets, jugs, basins, timba or draw-buckets, and vessels of various kinds, and thus attracted attention to the substance, which has since been applied in Europe to a vast variety of domestic and scientific purposes. Their method of collecting the gum, however, has latterly been of the most destructive kind. They fell the trees at once, and by removing strips of bark at intervals, collect indeed a large quantity of sap at one thne, but destroy all future supplies from that source. The tree was formerly very abun dant, but all the large timber was soon felled. When 20 to 30 years old, it was cut down, and the smaller branches cleared away. Round the bark of the trunk and the larger branches circular incisions are made, at a distance from one another of a foot or a foot and half, and in a few days all the sap dribbles and falls into a cocoanut shell or other vessel placed below. The portions of juice are then collected into bamboo pitchers, and carried by the collectors to boil it, at their huts, in large caldrons, in order to steam off the water which has mixed with the juice, and to clear it of impurities. After it assumes its marketable consistency, and is brought for sale (Cameron). Pure gutta percha is
greyish white, but it is generally brought to market of a reddish-brown hue. This is ascribed to chips of the bark which fall into the sap and give it their colour ; but in addition to this there are fre quently other matters, such as sawdust, purposely introduced RS adulterants. Dr. Montgomerie of Bengal appears to have first noticed the native use of this substance in 1842. In 1843, Dr. d'Almeida presented a specimen of the inspissated juice to the Royal Society of Arts, and described some of the advantages which would a,ccrue from its use. This communication led to no results. But another, made shortly after by Dr. Mont gomerie, was most successful, so that by the united efforts of these gentlemen gutta percha was introduced to public notice, and by the year 1858 about 2000 tons were annually exported from Singapore. In 1881, Great Britain imported 3422 tons of it from all places. A very small quantity, comparatively speaking, is to be ob tained by tapping.
Dr. Oxley says that gutta ought not to require an elaborate process. The simple boiling in water, and rolling out into sheets, from which all foreign matter can be easily picked off, is the only process he employed, and this, he thinks, would be generally sufficient, if manufacturers in giving their orders would take the precaution of requiring that the article should be sbeined through a cloth at the time of its collection; and if they would encourage the natives to do this, by offering a somewhat higher price for gutta porde so prepared, a vast deal of trouble and expense might, in his opinion, be thereby saved, The great peculiarity which makes gut ta percha convenient and valuable for a variety of purposes is, that when plunged into boiling water it bocomes so soft and plastic, us to be easily moulded into any desired form, and this form it permanently retains on cooling. It was the discovery of this quality which first lerl the Malays to fabricate it into useful articles.