Klang and Port Swettenham are contiguous towns in the Federated Malay States, having a population of 4000 and a rainfall of 100 in. a year. At Klang the expenditure has been £3100, with an annual expenditure of £270, devoted to clearing and draining 332 acres. At Port Swettenham £7000, with an annual upkeep of £240, has been devoted to treating 110 acres. In Hong-Kong similar measures were carried out, with the result that the hospital admissions for malaria diminished from 1294 in 1901, the year when operations were begun, to 419 in 1905. Klang and Port Swettenham. +------------------+------+-------+------+------+------+------+ | Year | 1900 | 1901* | 1902 | 1903 | 1904 | 1905 | +------------------+------+-------+------+------+------+------+ | Cases of Malaria | 510 | 610 | 199 | 69 | 32 | 23 | +------------------+------+-------+------+------+------+------+ * Nearly all were relapses of previous infection. A systematic campaign for the destruction of breeding-places has been inaugurated in the British West African colonies, with encouraging results. The planting of eucalyptus trees is out of favour at present, but it appears to have been successful in Portugal, not from any prophylactic virtues in the plant, but through the great absorption of moisture by its deep roots, which tends to dry the subsoil. Treating the breeding-ponds with petroleum or similar preparations seems to be hardly applicable on a large scale, and in any case can only be a temporary expedient. H. Ziemann advocates the destruction of mosquito larvae by the growing of such plants as the water-pest (_Anacharis alsinatrum_) which covers the surface of the water and suffocates larvae and nymphae. Short of suppressing mosquitoes, the parasitic cycle may theoretically be broken by preventing them from giving the infection to man or taking it from him. The means of accomplishing the former have been already pointed out, but they are obviously difficult to carry out on a large scale, particularly in native communities. It is one thing to protect individuals from mosquito bites, another to prevent the propagation of the parasite in a whole community. Perhaps the converse is more feasible in some circumstances--that is to say, preventing mosquitoes from having access to malarial persons, and so propagating the parasite in themselves. It could be carried out where the infected persons are few, by isolating and protecting them, but not where many are infected, as in native villages. Koch has suggested that the disinfection of malarial persons by quinine would have the desired effect, but other authorities of greater experience do not consider it practicable. In spite of the difficulties, however, there is no doubt that a great deal can be done to reduce, if not stamp out, malaria by the methods indicated, which should be applied according to circumstances. An encouraging example is