140 



Now I do not differ from Mr. Williams on any essential 

 point, except perhaps in regard to the conclusion as to which 

 grade is most homogeneous, which grade is the least variable, 

 and which grade is most satisfactory. Mr. Williams has told 

 us that they have abandoned any rubber except ordinary sheet 

 and biscuits, and yet he tells us that quite recently they had to 

 alter their heats very considerably I presume in regard to 

 those particular grades, though perhaps I am wrong as to that. 

 I take it that Mr. Williams' s reply to that would be that even 

 these variations' are less than the variations of the other grades. 

 Now, so far as my own particular experience goes, it is that 

 smoked sheet shows the smallest variation in regard to rate 

 of cure, also in regard to tensile properties, and also in regard 

 to general mechanical properties. I agree with Mr. Williams 

 that plain sheet is about the best rubber produced when it is 

 good; but my experience, based on a considerable number of 

 samples is, that it varies a great deal more than does smoked 

 sheet. Thus, of some fifty samples, half of which were smoked 

 sheet and half ordinary plain sheet, which were examined, the 

 difference in rate of cure on a single standard basis was: 

 smoked sheets, from one and a half hours to two and a half 

 hours; plain sheets, from one hour to over four hours. In 

 fact, there was one in the latter series which was almost uncur- 

 able under the standard basis. At the same time, the best 

 sample of plantation rubber I have ever had, I think, was plain 

 sheet, and perhaps Mr. Williams and the North British factory 

 have been particularly successful in selecting a very good grad'e 

 of plain sheet. I may say here that a factory such as the North 

 British, or one or other of the great factories in this kingdom, 

 is naturally in a position of great advantage as compared with 

 small manufacturers who cannot have an elaborate scientific 

 testing department; and, as Mr. Williams has well pointed 

 out in his article in the Rubber Exhibition handbook : 



" These troubles, in factories where scientific control is not 

 thoroughly organized, may be sufficient to condemn the use of 

 this grade entirely." 



I think, Sir, it is for this reason that the plantation interest 

 should work from every point of view for the purpose of 

 diminishing variability. In making this statement I refer 

 first of all to the work of the planter and the work of the 

 chemist at the other end, and to the work of the manufacturer 

 and the technologist at this end. I refer, in fact, to the 

 question of standardization in its broadest aspects. In making 

 this statement, I wish it to be clearly understood that when 

 we refer to the variability of plantation rubber, particularly 

 as compared with wild rubber, there is no intention to cast 

 a great big stone at plantation rubber at all. The best 



