300 



The Caoutchouc or Indian Rubber Tree. 



Vol. X. 



juices. Nature presents numerous similar 

 examples, which art cannot imitate; and 

 therefore we arrive at the inference, that 

 as the naturally prepared liquid manures 

 are the products of a species of slow com- 

 bustion by which vegetable and animal mat- 

 ters are resolved into their elements, they 

 must be most congenial to plants, as in fact 

 they derive their origin from them. 



While thus sanctioning the use of animal 

 liquid manure, we must protest against a 

 dirty and injurious method which we have 

 seen freely practised ; namely, by applying 

 fresh cow-dung, stirred up in a tub of water, 

 till it can be poured through the nozzle of a 

 water-pot. The water passes down and 

 conveys to the soil the dissolved salts and 

 liquefied gall of the manure ; but a cake of 

 dry, effete matter is deposited on the sur- 

 face, which prevents the ingress of air and 

 of water. The reason assigned is, that the 

 manure keeps the plant cool ! This is a 

 vulgar error which may lead to much mis- 

 chief. — Paxton's Magazine of Botany. 



The Caoutchouc or Indian Rubber Tree. 



{Fictts Elastica.) 



The tree from which the Elastic Gum or 

 Caoutchouc is principally obtained, is a na- 

 tive of India and South America. Its leaves 

 are of a bright shining green colour, thick, 

 oval, and pointed, and its fruit somewhat re- 

 sembling the olive in size and shape, which, 

 however, is altogether uneatable. It grows 

 very rapidly, and is said to attain the height 

 of about twenty-five feet, with a trunk of 

 one foot in diameter. Its usual size when 

 full grown, is about that of the European 

 Sycamore, and it seems to prefer mountain- 

 ous and rocky situations, being frequently 

 found in chasms and cliffs of the rocks on 

 steep and abrupt declivities of mountainous 

 regions, particularly in the province of Sil- 

 het, and in the lofty regions of Pundua and 

 Juntipoor. 



The sap or milk constituting the gum is 

 obtained from incisions made through the 

 bark in various parts of the trunk, and is 

 said to flow in greater abundance from those 

 which are made nearest the top of the tree. 

 This fluid which is at first of a yellow white 

 color, without either taste or smell, soon as- 

 sumes a darker hue on exposure to the at- 

 mosphere, and thickens until it becomes 

 solidified and forms about one-third of its 

 weight of the India Rubber, or Gum Elastic, 

 now so extensively employed in the arts 

 and manufactures of our country. 



This article was first introduced into Eu- 

 rope a little more than a century ago, and 

 was then only imported in the form of bot- 



tles, which were moulded over a form of 

 clay, and afterwards having been dried and 

 blackened in the smoke of the fires over 

 which they were suspended, the clay moulds 

 were crushed and shaken out, and the article 

 ready for export. 



The genus of which this tree is a species, 

 is possessed of very diversified and opposite 

 qualities. Some of the species yield a de- 

 lightfully cool and refreshing beverage re- 

 sembling milk, as the American Cow-tree, 

 and others the most fatal poison as the dead- 

 ly Upas of Java; the leaves of one kind 

 being found to be a tonic, others acting as 

 an emetic, while others still are caustic, 

 and all through the various range of differ- 

 ent qualities, yielding very profusely caout- 

 chouc. 



This gum is of grea'i, and growing im- 

 portance in our manufactures and the useful 

 arts, and may be applied to almost an indefi- 

 nite variety of useful purposes, being emi- 

 nently elastic and impervious to water; and 

 on this account is largely employed in the 

 manufacture of sundry elastic and water- 

 proof goods, as elastic bands, braces, ga- 

 loches, portmanteaus, bottles, catheters, bou- 

 gies, probes, boots, shoes, coats, carriage- 

 tops, bands for machinery, life-preservers, 

 beds, cushions, chair-seats, door-springs, &c., 

 &c. 



It is used in the manufacture of various 

 water-proof varnishes — for the removal of 

 pencil marks from paper, and for numerous 

 other purposes. It has lately been used, 

 with apparent success, as an article for pave- 

 ments and floorings, after the manner of as- 

 phalte. Tubes are formed of this substance, 

 by cutting it into uniform slips of a proper 

 thickness, and winding it around rods of 

 glass or metal, so that l;he edges shall be in 

 close contact; a piece of tape is then wound 

 round outside it, and in this state it is boiled 

 for two or three hours in water, when the 

 edges will be found to be sufficiently adhe- 

 rent. Pieces of India rubber may be joined 

 by moistening their edges with a solution of 

 it in ether, turpentine, or naptha; or they 

 may be softened by simply boiling them in 

 water, or touching them with either of the 

 above solvents. The parts being, in each 

 case, immediately pressed tightly together, 

 will be found to unite very firmly. India 

 rubber is very soluble in ether, mineral nap- 

 tha, and turpentine, and in the fixed and 

 many of the volatile oils. It may be pro- 

 cured from the ethereal solution in an unal- 

 tered state. 



The celebrated patent mackintoshes are 

 made by dissolving Indian rubber in hot 

 naptha, distilled from native petroleum, or 

 coal tar. The jelly-like paste so formed is 



