The former is by far the more effective measure ; it should 

 always be practised when the disease occurs in the neigh- 

 bourhood or when it has occurred on the plantation in 

 previous years. 



The fungicides which are most commonly in use may be 

 enumerated as follows : 



Sulphur, which is applied in the form of " flowers of 

 sulphur " by means of an instrument of similar construction 

 to a " powder-puff." 



Liver of Sulphur ; applied in the form of a solution of I Ib. 

 in 40 gals, of water by means of a spray. 



These two fungicides are in general use for superficial 

 moulds. 



Bordeaux Mixture, consisting of quick lime (4 Ib.), copper 

 sulphate (4 Ib.), and water (50 gals.) The quick lime should 

 be in lumps, so as to ensure its having been recently prepared. 

 The copper sulphate should contain as much as 98 per cent, 

 pure sulphate of copper. The mixture is best prepared 

 as follows : Into a * wooden vessel, such as a tub, whose 

 capacity is 25 gals., 4 Ib. of copper sulphate are dissolved ; 

 the solution is effected by suspending the copper sulphate, 

 wrapped in a piece of coarse sack, below the surface of the 

 water by tying it to a pole which is laid across the top of 

 the tub. In another tub, holding 25 gals., 4 Ib. of quicklime 

 are slacked ; the water is added slowly at first and the 

 solution is finally made up to 25 gals. The solutions of 

 copper sulphate and lime are then poured together into a 

 tub whose capacity is 50 gals. ; during the process the 

 mixture is stirred, and a final stirring of three minutes 

 duration is made after the solutions have been mixed. 

 The mixture is now tested with the blade of a knife or with 

 any other piece of iron ; if a red deposition of metallic 

 copper is formed on the surface of the iron, more lime 

 must be added. The mixture must be fresh when it is 

 used and should always be strained immediately before it 

 is transferred to the spraying apparatus. The spraying 

 machine should have a fine nozzle ; it is essential that in 

 spraying a cloud of the mixture should be produced which 

 is capable of remaining suspended in the air for a time 

 before it finally settles on the plant. The nozzles recom- 

 mended by the Board of Agriculture (England) are 

 " Vermorel," which has several modifications, " Mistry " 

 and " Mistry Junior," of American make. Bordeaux 

 mixture is in general use for some diseases of cacao, for 

 some diseases of the cotton plant and for several others. 

 It is the cheapest and most effective fungicide known. 



*A metal vessel must not be used. 



