OlTClBKR 1. 191(1.1 



THE INDIA RUBBER WORLD 



never been even a slight epidemic of any kind in the rubber 

 region of Indo-China, 



At first seeds and even plants were imported into Cocliin China 

 from Ceylon, Singapore and Java : but the presence of crypto- 

 ganiic diseases in the rutibcr trees of these districts, led to a 

 decree in 1910 prohibiting the importation of Hevea plants into 

 Indo-China and pro\ i<ling for the disinfection of imported seeds. 

 Since that time ncu plantations have generally purchased their 

 initial plants or seeds uf tlie Belland, Ong-Yem and other earlier 

 plantations. 



SECONDAKV CULTURES: USE OF MACHINERY. 



Secondary cultures do not yet form an important element in 

 the rubber plantations of Cochin China. .A. little rice and some- 

 times maize is raised for the employes and the stock, and a cer- 

 tain amount of land is devoted to pasturage. The amount of 

 land given over to these purposes will necessarily increase when 

 land is worn and the need for fertilization with stable manure 

 or by turning under a crop becomes more pressing. Cocoanuts 

 and other native fruits are often raised, especially on the small 

 native plantations. The Locninh plantation has about 300,000 

 coffee plants, the Xa-cam plantation about 115,000, the Delignon 

 plantations in Annam about 125,000, and other plantations a 

 smaller number, making in all about 550,000 coffee plants. A 

 small plantation in Cochin China has about 11,000 cashew trees, 

 one in Annam about 10,000 kapok plants and another raises 

 annually several hectares of Soya beans. 



The cultivation of these secondary cultures in connection with 

 that of rubber demands a variety of agricultural implements. 

 The smaller plantations use native hand-made plows, harrows, 

 hoes, spades, etc., but the larger plantations use modern machin- 

 ery, such as traction plows, harrows, rollers, trucks and mowing 

 machines. The motive power is sometimes native cattle and 

 carabao and sometimes steam. With the development of this 

 industry, both intensively and extensively, there will come a 

 greater demand for agricultural machinery. 



Agricultural machinery is sometimes purchased in France by 

 the Paris representative of the plantation, but it is generally 

 bought of local importers. In either case it is imported from 

 France, although much of the machinery is of American origin. 

 The leading Saigon importers and dealers are Descours, Cabaud 

 ct Cie, Graf, Jacque et Cie, and Bonnefoy Freres. The directors 

 of these firms are also directors of large rubber estates in Cochin 

 China. 



T.APFIN'G AM) GATHERIXG. 



The rubber trees of the gray soil plantations are generally 

 tapped at the age of five or six years. By this time they have 

 attained a height of 15 or 20 feet and a circumference of about 

 18 inches. On some of the red soil plantations the trees reach 

 this size during the fourth year and are tapped at this age. The 

 half-herringbone method is almost universally employed. The 

 trunk is usually divided into fifths and two of these parts tapped 

 at once over an up-and-down extent of about 20 or 30 inches 

 per year. The tapping is generally done every day — except dur- 

 mg the months of January and February — tj'e middle of the dry 

 season, when the trees are given a rest. 



The table given below shows the volume in cubic centimeters 

 of latex produced each month by groups of selected trees on the 

 experimental station at (')llg-^"em during 1910; 



.Month. 1(1 Tret-. 20 Trees. 42 Trees. 



y^nuaxy . .cubic cculinu-tcrs 1,71.1 895 Not tapped 



February 1.253 4,159 Not tapped 



March 1.S20 9,821 3,865 



April 1,740 8,962 15,225 



May 1.557 9,034 15,110 



June 5.595 o,720 14,138 



July 4.795 7,680 11,585 



AngHM 7,194 11,073 12,330 



Month. 10 'trees. 20 Trees. 42 Trees. 



Septemlier 5,635 12,312 11,586 



Octoher 7,6.12 10,164 12,593 



Novenihtr 7.730 12,513 11,892 



December 7,439 9,010 12,962 



Experiments made at the same time show that the weight per 

 cubic centimeter of the latex is a little greater during the season 

 of heavy production but that it contains a smaller percentage of 

 rubber than during the dry season. The density of this latex 

 varied from .88 to .98 grams per cubic centimeter, the amount of 

 dry rubber produced per gram of latex varied from .30 to .72 

 grains. Making due allowance for unusual conditions, these 

 tables give a fair composite picture of the relative productivity 

 of the different seasons of the year. 



The latex is gathered daily. A native can tap from 300 to 400 

 trees a day and gather latex from about an equal number. At 

 the Suzannah plantation, where native labor is very efficient, the 

 director hopes to bring this amount up to 600 trees per man ami 

 450 trees per woman. Since the beginning of rubber cultivation 

 in Cochin China tlie average annual rubber production per tree 

 has been about three-quarters of a kilo ; but the old Belland 

 plantation claims an average of lYz kilos for 1915, and some 

 portions of the newer plantations are said to average ovef a kilo 

 per tree. .As the above tables will show, selected .groups of trees 

 at Ong-Yem have produced over 5 kilos each per year. In con- 

 sidering these figures it must be borne in mind that up to the 

 present time most of the trees tapped each year are new and that 

 the trees have been planted too close together to obtain the 

 best results. 



METHOD OF FKEPARATION. 



The metliods of preparation vary slightly on the different 

 l)lantations. The first step is to strain the latex. To prevent 

 the too rapid coagulation a little water is sometimes placed in 

 the receptacles in which it is collected. The latex 14 strained 

 through a fine sieve, which collects all the leaves and other im- 

 purities, and is then placed in porcelain-lined basins about 

 8 by 12 inches and 3 or 4 inches deep and allowed to coagulate. 

 Sometimes a solution of acetic acid is added to assist the coagula- 

 tion. 



The coagulated mass is then passed several times through one 

 or more sets of rollers until it is pressed into thin sheets. Some 

 plantations have a heavy set of smooth rollers which merely 

 press the rubber into sheets and smaller rollers which impress a 

 design upon them. The rollers are generally of steel or zinc. One 

 of the leading plantations has employed copper rollers, but is 

 considering a change due to the objections of prospective pur- 

 chasers of the product. When finished the sheets are about 11 

 or 12 inches wide, 20 to 24 inches long and Ys to % inch in 

 thickness. These sheets are then taken to the drying room. 



The strainings of the latex, the lumps found on straining, the 

 water left in the cups, basins and other receptacles and the foam 

 and other skimmings after straining are prepared into various 

 grades of rubber and "scraps." 



The rubber is sometimes dried by natural air in a closed room, 

 sometimes dried with hot air and sometimes simply exposed in 

 a dry place to the tropical atmosphere. The first of these methods 

 is followed at Xatrach, the second at Suzannah and the third at 

 the Belland plantations and in general at all the smaller planta- 

 tions. Tiie Suzannah plantation has a $14,000 drying plant, con- 

 sisting of an "Ouragan" mechanical drier operated by a 75 horse- 

 power motor. The rubber produced on this plantation is ready 

 for market within ten or twelve days after leaving the tree, 

 while on other plantations of Cochin China the preparation of 

 the rubber re(|uires from twenty to thirty days, according to 

 the season. Some plantations smoke the sheet rubber in the 

 closed rootu by conducting wood-smoke into the room through a 

 pipe ; others by the addition of a little creosote to the latex. 

 (To he continued.) 



