juLV, 908.] 



5 



Saps and Exudations. 



flat, alluvial banks of the river are espe- 

 cially adapted for the growth of the 

 native species of Sapium, and thousands 

 of acres of this land might be utilized in 

 the cultivation. 



The terms on which land is leased for 

 rubber-planting purposes by the Govern- 

 ment of British Guiana were summa- 

 rized in the Agricultural News (Vol. 

 VI, p. 409), and they are certainly favour- 

 able enough to encourage men of means 

 to test the rubber-producing possibilities 

 of the colony. 



During the year 1906-7, 2,563 lb. of 

 rubber and 634,222 lb. of balata were 

 exported from British Guiana — The 

 Agricultural News, Vol. VII, No. 153, 

 March, 1908. 



PREPARATION OF CRUDE RUBBER. 



By Dr. Pehr Olsson-Seffer. 



(Extracts fi'om paper read before the 

 first meeting of the Mexican Rubber 

 Planters' Association on October 10th, 

 1907.) 



During the last few years much has 

 been done in regard to the progress of 

 the preparation of crude rubber, and 

 as we stand at the present day we are 

 able to make rubber which is far supe- 

 rior to the product placed on the market 

 a few years ago. I will here briefly dis- 

 cuss the various methods of collecting 

 and preparing rubber such as they have 

 been gradually developed. 



Tapping Tools.— All of you know that 

 throughout Central America the native 

 machete is used for the purpose of open- 

 ing the bark of the rubber tree to permit 

 the latex to exude. It stands to reason 

 that such a crude method cau be greatly 

 improved on. As a matter of fact, trees 

 tapped by means of machete incisions 

 are badly injured, and as a result they 

 are generally attacked by diseases, and, 

 after lingering for a longer or shorter 

 time, they finally die on account of the 

 injury. I have seen planted trees in 

 Mexico, which, after having been tapped 

 with machete for twelve years, are now 

 useless, because it is almost impossible 

 to tap them as they are so badly scarred 

 and cut. 



Rubber planters soon found out that 

 they must have a better tool for tapping 

 if the industry was to become a perma- 

 nent success. Some of the first improve- 

 ments in tapping tools were made in 

 Central America, where many years ago 

 a tool somewhat resembling a farrier's 

 knife was made by turning over the 

 point of a machete, and the tool was used 

 {or pulling, thus making an incision or 



groove in the bark. A somewhat simi- 

 lar idea was developed in a tapping 

 device, figured in James Collins' book 

 "Report on the Caoutchouc of Com- 

 merce," which was published in 1872. 



In later years other variations of the 

 farrier's knife have been used. Two 

 years ago I had a knife made on this 

 principle, and this crude sample made 

 by a native blacksmith in Chiapas was 

 the origin of the so-called Zacualpa 

 knife, of which much has been written 

 and said, as it was patented by a person 

 who happened to see it used. (Samples 

 of these knives were exhibited.) 



Knives of this same type are used in 

 Brazil for tapping Mangabeira and 

 Ceara rubber, and the various modifica- 

 tions of the V-knives are but develop- 

 ments of the farrier's knife. One of 

 these V-knives was patented iu Ceylon 

 by F. Holloway, and this knife has been 

 widely used also in Mexico. It is evi- 

 dent, however, that all these knives 

 give a wound, the edges of which are 

 more or lese torn, depending upon the 

 sharpness of the tool. One needs but 

 examine the incision under a microscope 

 to find that the cells and vessels of the 

 bark are fringed, and not cut through so 

 as to leave a clean opening. These 

 fringes naturally impede the flow of 

 latex, and the result is that we do not 

 get the amount we ought to. 



Before discussing the latest develop- 

 ment of tapping tools, I wish to draw 

 attention to some other knives, built on 

 different principles. Most of these have 

 been developed in Ceylon, where the 

 number of* " patented" tapping knives 

 is almost as numerous as that of the 

 rubber plantations. The Bowman and 

 Northway knives, which have been 

 widely advertized, and which are quite 

 extensively used for tapping Hevea trees 

 in Ceylon, are useless for Castilloa, as 

 they are entirely too weak- One of the 

 series of three of these knives is the 

 so-called " pricker," which is a kind of 

 a spur. The object of this is to cut the 

 latex tubes near the cambium and 

 thus increase the flow of latex. The 

 objection to this is that it often causes 

 abnormal development of tissue, and the 

 wound upon healing will not be smooth 

 but "bumpy." Macadam's comb-pricker 

 is a very formidable looking weapon, 

 and does its work in opening the latex 

 tubes, but is unpractical on account of 

 the labour it requires. You can easily 

 realize that such a tool is not what we 

 want where labour is paid at the rate of 

 $1 a day. 



The different nature of the Hevea tree 

 hae called forth different requirements 



