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which of the products (i.e., from old or new sources) is best suited 

 to his existing methods, which methods are the result of a long 

 experience with his original sources of supply ; but it becomes 

 ultimately a question as to which product will suit him best in the long 

 run if both are worked under the most favourable conditions. 



This is the state of affairs in which the rubber industry in the 

 course of time will find itself, or more particularly that branch of the 

 industry which deals with the production of high-class rubber articles 

 of which Para rubber is an important ingredient. Up to within the 

 last three or four years the world drew its supply of raw rubber from 

 trees growing wild in various tropical areas. Some ten years ago a 

 beginning was made with planting — particularly in the Malay Penin- 

 sula, and later in Ceylon — chiefly with Hevea Braziliensis, or the Para 

 rubber tree, but as no commercial yield of rubber is obtained until 

 the tree reaches its fifth or sixth year the effect of this planting is only 

 just beginning to be felt, and the imported plantation rubber at the 

 present time only forms about one per cent, of the total production. 

 From the large areas now in process of being opened up, this produc- 

 tion must increase considerably in the course of the next ten or fifteen 

 years, until eventually the plantation rubber forms a considerable pro- 

 portion of the supplies to rubber manufacturers. 



The properties of rubber are not only dependent upon such things 

 as soil, locality, climate, etc., but are largely affected by the methods 

 used in curing and preparing it for the market; and as the methods of 

 coagulation and preparation differ radically from those used in the 

 case of wild rubbers this consideration particularly applies to planta- 

 tion rubber. Without going into any details it may be stated that in 

 the former case the methods are primitive and indequate, except in 

 the case of the smoked rubbers, while the planters by common-sense 

 precautions, and in some cases by the use of simple coagulating, 

 washing, and drying plant, have sent to this country consignments 

 which are unequalled from the point of view of purity and general 

 excellence. It has, however, been asserted, without apparent reason 

 that, in spite of these desirable qualities, the plantation rubber is 

 wanting in the " nerve " especially attributed to hard cure Para. 



The object of the present paper is the discussion of a number of 

 preliminary tests made with the plantation rubber with a view to 

 testing its qualities and comparing it with a typical high-class rubber, 

 such as hard cure Amazonian Para. The methods employed in valua- 

 tion of rubbers as carried out by brokers and merchants would be 

 useless for this purpose. The broker looks for adulterants, and tests 

 the physical qualities by the general appearance, smell, and feel of the 

 rubber. Such tests cannot, except in the roughest manner, be of any 

 value in forming an estimate of the qualities of plantation or any other 

 rubber from a manufacturer's standpoint. A carefully conducted 

 chemical analysis will, however, be of some help. 



