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tween the bark and the wood is the growing part of the tree, a 

 tissue called cambium. This part alone has the powers of form- 

 ing new bark and new wood. If a cut is made which does not go 

 into the cambium, the cut will not heal over with new material. 

 Of course, it will dry up and turn black, and in this way protect 

 the tissue under it, but the piece of bark taken out is gone for 

 good. On the other hand, a cut made just to the cambium will 

 heal quickly. 



The Para rubber tree (Hevea) shows some important differences 

 in latex from the Castilloa. Of course all that I have noted on this 

 tree is done here in Nicaragua and it may behave differently in 

 Brasil or Ceylon. The first noticeable thing in cutting the Para 

 tree is the small yield. When a Castilloa is tapped, the cut is 

 immediately filled with latex, which runs in a small stream from the 

 lower end. The Hevca when first cut shows no latex. In a few 

 seconds it begins to appear in drops on the cut surface and after 

 3 to 5 minutes begins to drop from the end of the cut. The small 

 yield at the first tapping seems to be balanced by the fact that 

 more can be got by multiple tapping. In Ceylon, according to 

 report, the yield increases each day, but here I have noticed no 

 increased yield. I tapped one tree nine days in succession, and 

 though it yielded every day (a thing which Castilloa would not do) 

 the yield decreased instead of increasing. The Hevca tree will 

 not do here because there is too nuch labour involved in multiple 

 tapping. I think the trees here, if tapped rightly, would yield as 

 much as those in Ceylon, but as labour cost so much more, it 

 would not pay. I am confident from comparing yields printed in 

 The India Rubber World that Castilloa will yield as much with 

 four tapping operations a year as Hevea will with ten or twenty 

 when the trees are the same age. 



COAGULATION OF CASTILLOA RUBBER. 



Mr. S. W. Sinclair, Manhattan Plantation, Bluefields, Nicaragua, to 

 Director of Public Gardens. 



Manhattan Plantation, 

 February 2nd 1906. 

 Dear Sir, 

 Your favour of June 23rd 1905 has just reached me. 

 Replying to your enquiry about the Sinclair Coagulator, beg to 

 say that it consists of a piece of board through which holes are 

 bored 2 ins. by 2 ins. (holes should be about i inch). Over this 

 board a sheet of absorbent paper is placed, (I enclose sample) ; 

 paper must be laid on the board wet, if put on dry, it will warp 

 and give an uneven sheet of rubber. Having the board and paper 

 laid on wet, now proceed to tack on the rim or frame, which should 

 be from l\ in. high to li in. and your box will be ready for coagu- 

 lating. As soon as the latex is brought in from the field, I add 

 four times its volume of water, then strain through a fine metal 

 sieve ; then I place the whole in a cone bottom tin tank to settle, 

 which takes about one hour. I then decant off the water until the 



