§4^ 



THfiJ TKOmCAL AGRICULTURIST. [June i, ^887. 



less varnish, whicli dries rapidly on exposure to the 

 air. Dammar comes principally fram the Lampong 

 islands and Sumatra, and the yearly receipts may be 

 given at about 32,000 cwt. Tiiis resin is produced by 

 many kinds of trees in the State of Perak. The 

 principal are Bammar nvxta lutching I). Mcravti D. 

 Laiit, D. Degon, and Bammar Balk. _ It is the sap 

 ■which exudes spontaneously, and being exposed to 

 the air, acquires a flinty hardness, from which the 

 epithet batu, or stone, is given, to distinguish it from 

 the softer resins. The dammar is found either in large 

 masses, at the foot of tress which yield it, or float- 

 ing in rivers, drifted to them by the floods of the 

 rainy season. The natives apply it to most of the 

 uses to which we put tar, pitch, and resiu. Most of 

 the family of Bipterocarpeav yield balsamic, resinous 

 juices, those of the genus Dipterocarp^i.^ the wood oils, 

 and of Vatcria indurated dammar. The natural order 

 abounds in Sumatra, Java, and Borneo, which are the 

 chief sources of the dammar of commerce. In Borneo, 

 dammar is generally found in the ground below the 

 trees, but may occasionally be seen in huge masses, 

 not unlike icicles, hanging from the sides of the trees. 

 A single piece weighing 6 cwt. has been found on one 

 tree, but necessarily these large masses get broken 

 in collection. The value of the dammar found in the 

 Sandakan district, North Borneo, is rarely over 10s. 

 per cwt. Further to the north much better sorts are 

 found, the dammar mata kutching (or cat's-eye), 

 of Palaman, brings £2 per cwt. Of resins, chiefly 

 dammars, we import 20,000 cwt. from Singapore, and 

 6,Ij00 cwt. from Java. Two or three species of dammars 

 are met with in British India, but are of no great 

 commercial value. Canarium strictum is known in 

 Malabar under the name of the black dammar tree, 

 in contradiction to the Vateriaindica, known as the 

 •white dammar tree. 



The Sal tree (Shorcarolasta) furnishes also a dammar, 

 which dissolves much more freely and speedily in 

 benzole than in spirits of turpentine. The resin is 

 usually of a pale, creamy colour, nearly opaque. Shorea 

 sericea yields a kind of dammar which closely re- 

 sembles the Indian kind. 



Hopea odoi'ata, of Burma and Pegu, yields the rock 



dammar of commerce, a yellow resin which dissolves 



readily. The trunk of Jlopea Mingarawan furnishes 



a white dammar of a superior quahty. The resin 



yielded by Hopea Micrantha in Borneo, Sumatara, and 



Malacca is not so good, but that obtained from 



Belambang is much sought after for the lustre it gives. 



This resin is of a yellowish colour, and exudes in large 



lumps from the trunk and branches. It is soluble in 



turpentine or benzole, and forms a clear limpid varnish. 



The Kauri gum of commerce is the produce of 



Bammara Australis, a coniferous tree, which occurs 



only in the north island of New Zealand, over a large 



area of land which has been exhausted by forests in 



past ages, and is now barren. The turpentine that 



has exuded from the dead trees is found at a depth 



of from 2 ft. to 3 ft. Tht' export of this fossil resin 



has been steadily increasing the last thirty years. In 



1855 only 355 tons were shipped, whilst in 1883, 1884, 



and 1885 the annual shipments were over 6.000 tons, 



valued at£320,000. We received in 1885, 81,000 cwt.. 



valued at £254,000. This fossil rosin is often found in 



immense masses, larger than those of any other 



known resin. Fine Blocks were shown in the New 



Zealand Court at South Kensington last year, as 



well as large collections of trade samples ot the 



different commercial varieties. 



Copal of Zanzibar.— This, sometimes called Indian 

 Anime, has been found to be the produce of Hymenaea 

 Mosamhicensk, or Trachylohium viosambicense. The iionth 

 American species Hymenaea courbaril also yield a good 

 deal of resin. The "true, or ripe copal, is the product 

 of vast extinct forests overthrown in former ages. 

 The export from Zanzibar averages about 1,000,000 

 pourds annually. The raw, or true copal, is called 

 Ohacki'Ze, corrupted by the Zanzibar merchant ta 

 jackass copal. Copal, it may be remarked, is the Mexi- 

 ca-n generic name for all resins. Manila copal derive 

 its name from the port from which it is shippe 

 there are two varieties known as bard and soft Manila 



the hard resembles kowrie in appearance, but is inferior 

 in <iuality ; the soft is a pale yellow kind resembling 

 dammar. From Hymencea coiirharil, the soft re.sin known 

 in commerce as American copal, is obtained. The tree 

 is very extensively diffused over the West Indies, British 

 Guiana, Venezuela, Mexico, and in almost all the pro- 

 vinces of Brazil, though some other species of Ilymencea 

 probably furnish the resin. It is found in many loca- 

 lities in a semi-fossil state, and is obtained by digging 

 in the vicinity of the roots of the tree. The masses 

 seem to have the appearance of a stalagmitic form- 

 ation, arising from exudations from the branches of 

 the tree dropping in the soil below. Guibnvrtea co-pal - 

 lifrra is the principal, if not the sole, source of the 

 copal resin of Sierra Leone. All the resin exported 

 under the name of West African copal, may be looked 

 upon as a fossil resin, produced in times past by trees 

 which, at present, are extinct, or exist only in a 

 dwarfed posterity. The origin of the kind of copal 

 known as Angola, is at present undetermined. Con- 

 siderable quantities of copal are washed down during 

 the rainy season from the slopes of the mountains. 

 The natives subject the copal to a rude washing in 

 lixiviated ashes, whereby the outer crust and its im- 

 purities are partly removed. It has, on arrival to be 

 further cleansed for the trade with extreme care, and 

 without the use of acids, which are very detrimental 

 to varnishes in causing them to run " pin-holey." The 

 flat Angola copal is sometimes called red animi, as 

 it somewhat resembles it in appearance and quality. 

 It is principally sent from here to Europe and America. 

 The rounded water nodules, known as "pebble copal," 

 assume this form, from the abrasion consequent on 

 their being washed down by the rapid mountain currents, 

 from the beds of which they are obtained. 



The anime of commerce is a resin of great value to 

 the varnish maker, but it is now largely replaced by 

 copal. The best is obtained from Zanzibar, and is 

 derived originally from Trachylolnum musamJiicriixe. The 

 finer qualities come from the northern districts of 

 AYande. The imports are never very large, seldom 

 amounting to 3,000 cwt. Of copal, the imports occa- 

 sionally reach 20,000 cwt. but the imports from AVesi^ 

 Africa are only about 7,000 cwh Of dammar the im- 

 ports range from 3,000 to 7,000 cwt. and of kowrie 

 gam, 70,000 cwt. to 80,000 cwt. annually. — Journal of 

 the Societi/ of Arts. 



♦ 



ON THE USE OF SOOT. 



As an April top-dressing for wheat, soot has been 

 applied in certain districts for very many years, with 

 most satisfactory results. Indeed, before the intro- 

 duction of Peruvian guano and nitrate of soda, it 

 was probably the only spring top-dressing employed; 

 while its use on certain soils was regarrled more as 

 a preventive against fungoid and insect attacks than 

 as a source of plant food. Doubtless it is owing to 

 this preventive property that soot has retained its 

 po';ition as a favourite dressing with many practical 

 farmers, so that its cost has rather increased than 

 decreased. 



If we compare the relative amount of available 

 ii't^rogen compounds supplied by soot and by nitrate 

 of soda respectively at the same cost, the economy 

 is cert.iinly largely in favour of the latter; for not 

 only is the nitrate, on account of its richness in 

 nitrogen, much less bulky, and therefore less^ costly 

 in the matter of carriage and subsequent distribution, 

 but there is the advantage that it can be purchased 

 with a definite guarantee as to its chemical composition; 

 whereas soot is subject to all kinds of adulteration, 

 and its quality, moreover, must necep.sarily vary with 

 the character of the coal consumed in diflTerent localities 

 so that it is quite impossible to get any quantity at 

 a uniform standard of purity. The only ready test 

 of quality is its weight per bushel, for the less the 

 weight the richer in ammonia-salts, and. consequently, 

 the morp. v:ilu»ble the soot. As we shall presently 

 see, upon making a careful comparison of the chenai- 

 cal composition of the best qualities of soot with 

 ordinary nitrate of soda, the latter is the more 

 valuable of the two if we consider it simply as a 



