572 the Supplement to the Tropical Agriculturist 



safer to repeat this process after washing. Un- 

 fortunately, on most plantations up till now, the 

 latex has not been disinfected at all, and, with 

 the exception of Amazona rubber, very little 

 that has been disinfected is put on the market. 

 The planters generally consider adding coagula- 

 tion medium sufficient. 



In the past, coagulation has been chiefly 

 promoted by means of acetic acid, and, in a few 

 cases, by centrifugal force. Some planters, how- 

 ever, allow the latex to coagulate from natural 

 causes. Formic acid, which acts at the same 

 time as a disinfectant, and creosote, which only 

 disinfects, are very little used for reasons given 

 later on. Only just lately, a preparation of fluor, 

 which is sold under the name of " Purub, ; ' and 

 which both disinfects and promotes coagulation, 

 has come into use. 



By adding acetic acid, the latex is simply 

 acidified, and coagulates ; the mass of rubber 

 thus formed must then be dried as thoroughly 

 aud quickly as possible, so that germs of decom- 

 position may not come to life in the excellent 

 fostering soil, rich in albumin, open to them. 



Likewise, if coagulation is promoted by cen- 

 trifugal force, it is only by thoroughly drying the 

 rubber that germs of decomposition can be 

 destroyed. 



[The next passages are devoted to explain the 

 advantages of Mr. Sandmann's own patent, 

 " Purub ;" while subsequent ones deal with all 

 matters up to arrival at market. We quote the 

 last sentence : — ] 



It is most urgent that planters should con- 

 sider it their duty to do all injtheir power to give 

 plantation rubber the place it deserves on the 

 world's market, especially just now, when, on 

 account of the high prices, the prospects are so 

 good. 



ARTIFICIAL MANURES. 



And the Over-Production of Phosphates. 



There is no doubt an ever-increasing demand 

 for artificial manures, due to the increasing 

 attention that is being paid all over the world 

 to scientific methods of agriculture. Although 

 phosphate rock is an extremely useful raw 

 material for artificial manuremanufacturer3, the 

 question has recently arisen whether the pro- 

 duction of phosphate may not soon exceed the 

 world's demand. At the present time the world's 

 annual production of phosphate rock is about 

 5,000,000 tons, the United States, with an annual 

 output of more than 2,000,000 tons, being the 

 largest producer. Tunis comes next and in 1909 

 one Tunisian company, the Gafsa Company, 

 mined 907,000 metric tons. The Pacific Phos- 

 phate Company of London, which owns deposits 

 of 50,000,000 tons of high grade phosphate on 

 Ocean and Pleasant islands, is miuing some 

 250,000 tons a year. The island of Makatea, 

 which is situated in the extreme north of the 

 Tuamoto Archipelago, has an area of about 10 

 square miles, one-fifth of which is covered with 

 deposits of phosphates estimated at 10,000,000 



tons of an average grade of 82 per cent. The 

 Makatea deposits are being developed by the 

 French Phosphate Company of Oceania. The 

 fears of over-production cannot be considered 

 groundless when the deposits are being exploited 

 with such activity as is being displayed by all 

 the phosphate companies. When the Makatea de- 

 posits are placing ou the markets several hun- 

 dred thousand tons per annum no doubt concern 

 will be expressed at the congested state of the 

 market by those who have themselves caused 

 the glut. — Indian Trade Journal, Nov. 24. 



"THE SUGAR BNDU3TRY OF THE 

 ISLAND OF NEGROS." 



By Herbert S Walker, of the Division of 

 Chemistry in the Government Sugar Labora- 

 tory, Philippine Islands, and published by the 

 Bureau of Science, Manila, is a comprehensive 

 report (accompanied by excellent illustrations) 

 of some 150 pages. The work represents the 

 first exhaustive and authoritative publication 

 treating of the sugar industry of the Philippines. 

 The Scientific Department of these islands is 

 earning a reputation by its research work, and 

 already wo have had some useful determinations 

 resulting from investigations regarding the life 

 history -and products of the coconut palm, 

 which is of particular interest to Ceylon as a 

 cocomit-growing country. Mr Walker's compre- 

 hensive report should prove of immense value to 

 all sugar-planting organisations and individual?, 

 and, though as a Colony we have no direct 

 interest in the product of the cane, we wel- 

 come any such useful publications as the one 

 before us. 



fflR. FETCH'S LATEST CIRCULAR ON 

 TJAGAO AND HEVEA CANKER. 



Dated September, which comes to hand only 

 today — sounds the knell of mixed cultivation 

 in Cacao and Hcvea plantations. He writes, 

 p. 170, that when Hevea is interplanted among 

 Cacao, the Cacao pods serve as a continual 

 source of infection for the Hevea. Moreover, 

 the dense shade of the mixed plantation favours 

 the growth of the fungus on both products. 

 The effect of canker on Hevea is more serious 

 than on Cacao. In Cacao, though the stem 

 is shaved periodically, the tree continues to 

 yield a crop until it is killed by complete 

 rings. But as the bark is the source of reve- 

 nue in Hevea, it is impossible to be always 

 cutting it away in the same manner. When 

 the whole of the bark on one side has to be 

 cut away for a length of two or three feet, 

 that tree is useless for tapping for several 

 months, and in all probability tho area will 



never be tapped again The chief 



preventive measure must be the removal of the 

 Cacao. — The foregoing must be anything but 

 pleasant reading to Hevea planters who have 

 cacao growing on their estates — say in Matale, 

 Dumbara and Kurunegala. — We must quote 

 further extracts another day. 



