



disease was first noticed in Java about 1876. Can the climate have become damper during that and the 

 following years ? There is no record of meteorological observation in Java till 1879, so that the rainfall 

 of the years preceding the appearance of the disease cannot be determined, but, if anything, it should be 

 greater then than now because of the recent great destruction of forests to make way for cultivations. 

 Here is a table of coffee production in three districts which have recently suffered heavily from the 

 disease, arranged in periods of five years : — 

 Average yearly 



production. Samarang. Cheribon. Madiven. 



In 1864-1868 ... 52,700 pikuls 24,900 pikuls 60.300 pikuls 



„ 1869-1873 ... 51,550 „ 22,500 „ 61,700 „ 



„ 1874-1878 ... 49,200 „ 22,700 „ 58,600 „ 



„ 1879-1883 ... 50,500 „ 24,600 ., 66,400 „ 



„ 1884-1888 ... 27,300 „ 11,760 „ 33,275 „ 



The fall in the last five years can hardly be attributed to a sudden alteration in the climate. A°-ain, 

 if as Dr. Peilen thinks excess of damp is the cause, mountainous districts and those parts of Java 

 where the rainfall is heaviest, such as Buitenzorg, the disease ought to be worst. This is not the case. 

 The theory of the same writer that the growth of the mycelium of the hemileia is dependent on the 

 degree of concentration of the cellular fluid in the leaf from which the fungus draws its nourishment 

 and that only when the concentration is small can the fungus grow, is not yet proved by experiment. 



Eradication of the Disease. 

 Two plans have been invented by Dr. Burck, both of which have been attended with highly satis- 

 factory results ; one of these is a repressive, the other the preventive method of dealing with the disease. 



The first of these consists of the destruction of the sick spot in the leaf. There are two forms of 

 apparatus in use. One of these consists of a small bottle of concentrated sulphuric acid through the 

 cork of which a glass tube passes. The coolie is supplied also with a fine needle of bamboo. The tube 

 passes about half way down the bottle, which is filled for \ or \ its length with sulphuric acid ; by 

 this arrangement there is no fear of the sulphuric acid escaping if the bottle is upset. The operator 

 dips the needle into the acid through the glass tube and then punctures the spot witn it, a verv small 

 quantity is sufficient to destroy the fungus, and the sick spot drops out of the leaf leaving' a hole 

 where the mycelium has been at work. This little instrument nas proved most successful, but it has 

 the disadvantage that the quantity of acid cannot be regulated and it is also liable to get upon and 

 burn the hands of the operator. The instrument-maker, Heckkking, at Sourabaya, invented a pair of 

 scissors for cutting out the spots, which is now used in many plantations in preference to the acid bot- 

 tle. The coolies apparently work faster with the scissors and more easily. A little tube on the scis- 

 sors receives the cut-out bits and when filled these can be thrown into water or otherwise destroyed in 

 order to prevent infection spreading, but in wet weather it does no harm to throw them down merely 

 upon the ground. 



As explained above, it is the third pair of leaves which shews the attack first : the fourth, fifth 

 and earlier pairs are already so badly attacked, that they are not worth attempting to save. The 

 operator then cuts out or burns with the acid the spots on the third pair on each branch. It is very 

 rarely attacked a second time as it very soon passes out of the stage in which it is most liable to attack. 

 In a month the third pair has become the fourth, and the pair above is the third ; this pair is then 

 treated in the same manner, and so on. Thus, two leaves on each branch, once a month, is all that is 

 required to be treated. Leaves thus treated instead of falling in eight weeks after infection remain 

 healthy and of a good colour for months, and the operation is so simple that, it can be performed by 

 children at a very low rate of pay. 



The cultivators, viz., Mr. F. W. Morren, President of the Blithan Company of Coffee Planters and 

 Manager of the Estate Bantarum near Mingi, and Mr. J. A. A. Taunay, Aministrator of Kawi-Sari 

 near the same spot, have tried the plan on a very extensive scale, i.e., of 220,000 and 170,000 trees re- 

 spectively, and were very satisfied with the result, and other reports were equally favourable. Mr. 

 Morren, in answer to a circular sent round for information, said that " It is my decided conviction that 

 "not only with me but on ever3 T private plantation the method can be applied even when the disease 

 becomes more severe," and Mr. Taunay supported the same opinion. Several other gardens gave good 

 reports, but in Paseroean and Bantam the reports of the treatment were unfavourable, that is to say, it 

 seemed to have no effect on the crops. However, it must be admitted that in some cases the disease may 

 become so bad that this treatment is useless. 



The Preventive Method. 



This will indisputably become the most general. It depends upon the treatment of the laves 

 with a chemical re-agent which acts fatally upon the fungus, but does not hurt the leaf. The spores of 

 hemileia are very sensitive to many kinds of re-agents, organic and inorganic, and experiments were 

 made with chloride of iron, sulphate of copper, nicotine, boric acid, sulphate of quinine, extract of cin- 

 chona bark, cupric hydroxide, mixture of lime and sulphur, cupric sulpho-stentite. 



The last mentioned gave no satisfactory result, it soon washed off the leaves. Iron chloride gave 

 good results at first, but the application on a large scale was found to be unsatisfactory on account of its 

 hygroscopiety, which prevents an accurate proportion being taken, and its liability to decomposition, by 

 which it soon loses its effect and is likely to injure the leaves. It is fatal to the fungus in doses of 1 

 part in 7,000 parts of water. Copper sulphate is more successful. It does not decompose ; it is very 

 cheap and easily obtained. It can be obtained in the form of powder, and dissolved easily in water. 

 One part per thousand of water was used with favourable results, but it will still kill the disease when 

 one part is mixed with 150,000 parts of water, so that the stronger solution dose would be quite strong 

 enough even if diluted by rain or dew to a large extent. 



