L68 



The question as to the besl means oi tapping also shares the 

 attention of Dr. Weber at (p. L31, An-.. L904, LR.J.) On this poinl 

 there is undoubted evidence (in our experiments) thai more latex can 

 be obtained from horizontal than from vertical cuts. As to the qui 

 fcion of ilic anastomosing <>l' the milk ducts, our author states that 

 there is "surprisingly little evidence," but it has been our fortune to 

 observe an instance where the rubber of a Castilloa tree had formed 

 and solidified in the milk ducts, and the bark having rotted away, it 

 left a perfecl casi in Rubber of the laticiferous system which was 

 found to give direct evidence oi their form. Thi casi showed perfect 

 anastomosis of the ducts. 



The contention of Dr. Weber as to the value of a vertical versus 

 a horizontal cut, is in noway effected, as it was found that the largest 

 channels were in a vertical position, the intercommunication being 

 effected by minor channels issuing from the sides oi" the larger. 



While it is certain that horizontal or spiral cuts or channels will 

 cause more latex to flow, the adoption of the practice of making such. 

 will rest almost entirely with the economy of labour in field work. 

 Only experience can show which methods are most useful in the field, 

 ascertained by the cost of tapping per lb. of latex, the injury to the 

 tree, and the amount of waste ; and such matters cannot be deter- 

 mined in the Laboratory. 



It is clear that the greater facility is afforded in making the cuts. 

 and the minimum of time in which the latex can be gathered, are 

 important factors in the economy of Rubber collecting, as the cost of 

 the methods of collecting Rubber from cultivated trees has hitherto 

 been no inconsiderable stumbling block to the owners of plantations. 



The invention of the new tool described by Dr. Weber is a step 

 in the right direction, and working on the same lines we are now in 

 possession of an instrument which alloAVS still more freedom to the 

 operator and enables him to make a narrow deep or broad channel at 

 will, with ease and despatch. This instrument will be figured and 

 described as soon as the manufacturer has obtained the necessary pro- 

 tection. It is sufficient for the present to say that by its use a greater 

 control of the flow of latex can be obtained than by any other method 

 yet seen by the writer. 



Our recent experiments, the result of which was published by the 

 Imperial Institute, show the value of Rubber at certain ages and it is 

 now fairly proved, that the amount of obtainable rubber is increased 

 as the age of the tree increases, and the amount of resinous matter 

 decreases in proportion to the increase, of Rubber, the tree being 

 apparently able to convert this resinous matter into Rubber of Com- 

 mercial value. 



The question of the density or fluidity of the latex, is one which 

 our experiments show is controlled almost entirely by the root system 

 of each tree and the water supply it obtains, and the state of growth 

 of the tree itself. If active, there are more fluids present, if dormant 

 less are to be found, and the latex wants fluidity when trees are tap- 

 ped at such a stage. 



Whether it is an advantage or a disadvantage to have a more or 

 less fluid latex, is a matter also for further experiment, as with a 

 rapidly flowing stream more waste is almost sure to occur, than with 



