THE PALMS OF BRITISH IXBIA AND CEYLON. 9o7 



idoomed once the disease appears and will jdeld no further profit, 

 its removal costs little but the actual expense of labour in cutting- 

 it down and burning it. To save healthy trees within the 

 affected districts in places where they are surrounded by large 

 numbers of dead or dying trees, is difficult unless the above 

 measures are very thoroughly carried out. But the chances 

 of their infection may be very largely diminished if they are 

 brushed with Bordeaux mixture on the leaf sheaths when the 

 removal of diseased trees commences. Bordeaux mixture is 

 a substance which adheres strongly to the surfaces of plants 

 and being poisonous to fungus spores, it prevents their germi- 

 nation or kills the young germ filaments as soon as they 

 appear. A second gang of toddy drawers should be employed 

 for this work and provided with small vessels containing the 

 mixture and mops of rags for brushing it on to the sheaths. 

 The expanded leaves need not be brushed, but only the leaf 

 sheaths below these. The men employed for removing diseased 

 trees should not be allowed to climb healthy ones, as there is some 

 danger of their conveying the infection on their persons or axes. 

 ^' To prepare 50 gallons of the mixture, weigh oiit 6 lbs. copper 

 sulphate, break to powder and dissolve in 25 gallons of cold water 

 by suspending in a piece of gunny sacking in the water. The 

 latter must not be contained in a metal vessel but in a barrel or 

 big earthenware pot. In another vessel weigh out 4 lbs. of fresh 

 quicklime. Slake this gradually till it falls to powder and then, 

 add water up to 25 gallons. Allow it to cool. When cool, add 

 to the copper sulphate solution through a sieve so as to retain any 

 Lumps. A thick bluish licjuid results which on standing throws 

 down a bluish precipitate, leaving the other part of the liquid 

 eleav. To test if fit for use, add a few drops of Ferrocyanide of 

 Potassium to a small quantity of the clear licjuid in a dish. If a 

 brownish precipitate appears, more lime must be added till no pre- 

 <cipitate is given on testing. Or a clean steel knife may be dipped 

 in it, and if more lime is necessary, a deposit of copper will form 

 •on the knife. If none is found, it is ready for use. Stir well 

 (before using.'' 



Since the time these suggestions were made, a large campaign 



