when they express an opinion, to let us know whether that 

 opinion is merely a general and pious one, or whether it is 

 based on direct experimental evidence ? I think that nothing 

 has been a more formidable enemy in the past to the plantation 

 industry than expressions of. opinion. 



Dr. H. P. STEVENS: Mr. President and Gentlemen This 

 subject has been so well covered by previous speakers that 

 very little else is left for me to discuss, and most of my remarks 

 will arise out of statements and opinions expressed by previous 

 speakers. 



The other day the General Manager of the North British 

 Rubber Company expressed the view that a great deal of pious 

 nonsense, as he phrased it, has been talked about variation in 

 plantation rubber, and it appears to me that there is a great 

 deal in what he said. Up to now those who have discussed 

 this matter have not appeared to see the necessity of defining 

 what is meant by " variation " and what is meant by " planta- 

 tion rubber." Dr. Schidrowitz has just given us a definition 

 of variation which I was very pleased to hear, and which, 

 generally, I should like to endorse. Rubber may vary in a 

 great number of ways, and any one of these variations will 

 affect the use of the rubber in the hands of the manufacturer. 

 However, we have not had up to now, apparently, a definition 

 of plantation rubber, and it appears to me that there has been 

 too much confusion as to what is meant by this term. Many 

 people, speaking of plantation rubber, think only of what used 

 to be termed first latex rubber that is to say crepe or sheet 

 prepared from latex, while others include in plantation rubber 

 not only the first qualities, but various grades of scrap, which 

 are prepared and worked up in various ways and sent home, 

 forming, perhaps, 25 per cent, of the total quantity. Finally, 

 there are those who would include in ''plantation rubber" 

 rubbers coming from plantations on the West Coast of Africa 

 and other places, which is very often not Hevea' rubber at all, 

 so that, before discussing the variations of plantation rubber, 

 it is very necessary that we should define what we mean by 

 plantation rubber. Statements have frequently been made that 

 plantation rubber is more variable than Para rubber. Now 

 such statements appear to me extremely unfair to plantation 

 rubber, because in fine hard Para rubber we have one definite 

 variety or grade, whereas in plantation rubber we may have 

 a great variety of grades; and for comparative purposes we 

 must confine ourselves either to all grades or to one particular 

 grade. 



Now Mr. Williams has given us the heats of cure of a 

 number of samples of plantation rubber, but I have no doubt 

 Jie would agree that we could get wider variations if we took 



