From this description it follows that, preliminary to mixing, it is necessary to thoroughly masticate or "plasticise" the raw rubber. Much of the "wild" rubber was of so inferior a quality that it very readily broke down, and but little mastication was necessary. It was soft and resinous, and readily took up the powders which were to be mixed with it. The better grades of wild rubber, such as Fine Para, were more difficult to break down, but not so difficult as most plantation rubber, because they had already received a preliminary "working" in the process of washing and crepeing, and we have already explained that such treatment takes more power than the crepeing of the soft moist coagulum on the plantations. The amount of "working" or "plasticising" produced in the rubber is connected with the power expended; the greater the expenditure of power, _caeteris paribus_, the greater the working effect on the rubber. Although the manufacturers possessed a relatively soft rubber in the form of washed Fine Para, it was customary in most cases to employ this rubber in conjunction with washed lower grades to produce a soft plastic material for further treatment. Now, however, the manufacturer has little else but plantation to deal with, and most of it more difficult to break down than washed Para crepe. This is the reason why a hard, tough rubber is no longer a desideratum with manufacturers, although originally taken as an indication of good quality. For the majority of purposes they want something which will break down easily. Hence if a rubber could be produced answering to these requirements, without loss of vulcanising quality, it would be preferred.