I206 



THE MALARIAL FEVERS 



be far from good. The Simpsonette anti-mosquito and fly protective, 

 non-inflammable headgear, designed by Mrs. Mary Simpson is most 

 useful, as it can be worn under or over the helmet or hat as well as 

 when 'lying down or sleeping. 



Secondly, with regard to gnat -proof rooms or houses, these can 

 be easily constructed at but slight cost by using wire-netting of 

 twenty to twenty-four meshes to the inch, preferably the latter. 

 Rooms and verandas enclosed in this way are a great convenience, 

 preventing molestation from mosquitoes and other insects. 



The Irrigation Department of Ceylon possesses movable mos- 

 quito-proof rooms, which its engineers can take with them as their 

 work requires. These are constructed of a wooden framework, 

 supporting the gauze, and have a double door. They are only 

 12 feet by 12 feet by 8 feet, and can therefore be erected inside the 

 room of a native house if desired, or on a veranda. The cost is 

 small. 



Hospital wards ought certainly to be rendered gnat-proof in 

 malarious districts, as persons are often found in the wards with 

 their blood teeming with gametocytes. Hence, if there are any 

 suitable anophelines in the hospital, the chance of future patients 

 suffering from other diseases becoming infected is considerable. 



With regard to coolies, the third method has been tried to a 

 certain extent with success — ^viz., that of rubbing all over the body 

 an oil composed of ij parts of citronella oil, i part of kerosene, 

 and 2 parts of cocoanut oil, to which i per cent, of carbolic acid 

 is added. Coolies seem to like this mixture, which is called the 

 ' bamber-green oil.' Menthol, cinnamon oil, eucalyptol, camphor 

 ointments or powders, may be used. 



Electric fans and punkahs are secondary methods of preventing 

 anophelines from biting human beings. 



Sulphur. — According to some authorities, mosquitoes and flies will not 



bite persons who take small doses of sulphur regularly, but this is not so in 

 our experience. 



The healthy may also be segregated as far from sources of infection 

 as possible. This may be temporary or permanent, according to 

 local conditions. 



The Anophelines, — ^It has already been indicated that it is not 

 necessary to exterminate the anophelines in order to prevent 

 malaria, but that all that is needful is to reduce their numbers. 

 The objection has been raised to anopheline destruction that as 

 fast as they are destroyed in a given area others will immigrate 

 into that place from surrounding areas. 



Ross has rather aptly answered that objection by pointing out 

 that if the human birth-rate in a place was suppressed without 

 attracting special immigration, the population would soon decrease, 

 and Professor Pearson, on conjectural bases, has shown that if mos- 

 quito propagation is suppressed within the circular area of a mile, 

 the mosquito density at the centre will be 3 per cent., a quarter of a 

 mile from the centre 18 per cent., and at the periphery 75 per cent. 



