44 CAOUTCHOUCS OH INDIA RUBBERS (Gostilloa). 
The milk flows much more freely than that of Hevea, so 
that one cnt seems to drain a much larger area of the stem. 
The native American methods of tapping are wasteful, and 
often cause the death of the trees. The method described 1 
under Para rubber, by cutting Y incisions at frequent 
intervals, seems to be the only one used in Ceylon. The 
milk here runs so freely that a simple sloping cnt is 
sufficient, and there is no need to make the Y. A sharp 
knife should be used, as the milk flows more readily and 
the wound is less ragged. The cuts need not be so close 
together as in Hevea ; they may be 3 or 4 feet apart instead 
of 1. A large quantity of milk flows from an incision, so 
that tins holding 150 c.c., or 4 ounces, must be used. The 
incisions are about an inch long, and should be confined 
to one side of the tree, or to not more than three-fourths 
of its circumference at a time. The milk is placed in 
a glass chum or other receptacle (machines for the 
purpose are occasionally used) in which it can be shaken. 
On standing, the caoutchouc floats to the top as a cream. 
The beery fluid below is run off by the tap. The cream is 
mixed with water, churned, left to stand, and the process 
repeated. The rubber is thus obtained almost pure in 
three creamings, and the cream is poured out to dry on 
a porous surface, when a thin sheet of perfectly dry and almost 
pure caoutchouc is obtained in a short time. Good results 
are obtained with less trouble by the use of the centrifugal 
machine, first applied to rubber separation by Biffen. 
Samples of Ceylon Gostilloa rubber, prepared by Mr. 
Parkin by the creaming method, were submitted to MM. 
Michelin et Cie, who reported that they were “rubber in 
very clean sheets, unusually fine for Castilloa.” On washing 
and drying the rubber lost nothing in weight. The film 
contained 91-78 per cent, of pure caoutchouc, 7*54 per cent, of 
Till further experience has been gained we do not know 
ow much tapping is Advisable in Castilloa , nor how much 
