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Mr. Gilman, who had also tried oiling on Bukit Jelutong Estate, 
said that, when he started, the death-rate on his estate in August, 
1915, was 88 per mille, at the end of that year it came down to 69. 
In 1916 the death-rate was 3 per mille. This year they had not had 
a death yet. He had 159 coolies and only had one death, from 
pneumonia, during the year. 
Mr. Huson asked for more information about the method of 
spraying. 
Mr. Harrison explained that he employed four coolies in each 
division with four sprayers, with a definite programme mapped out 
for each. They used crude oil in 65-gallon drums which were 
used for liquid fuel. One ordinary kerosene oil tin filled a spraying 
machine. Every scraj) of water in the area was oiled, in fact they 
even went across the road into the surrounding kampongs and oiled 
the wells there. (Laughter,) 
Mr. Jarvis thought the experience of Midlands, where half a 
mile of oiling was sufficient, did not agree with the statement that in 
Panama anophelines would fly a mile against wind, and asked 
Dr. Lucy what he considered was the limit of a mosquito’s operations. 
Dr. Lucy replied that as to mosquitoes travelling for over half a 
mile, he could not say definitely, hut many estates which had tried 
oiling found a radius of half a mile gave good results. It was 
not possible to lay down a hard and fast rule as to what distance 
anopheles travelled. In Panama experiments with painted anopheles 
showed that some travelled as far as 6,000 feet. 
Mr. Lawforb asked what was the safe margin around which 
water should be oiled ? 
Dr. Lucy said a great deal of enquiry was necessary before a 
hard-and-fast rule could be laid down. Certainly half a mile was 
the absolute minimum, and the further they went the better. Each 
case must be taken on its merits. As to the habits of mosquitoes, 
that- was a question they knew very little about, though the 
anophelines preferred clear running water, and were seldom found in 
dirty water. It was a question which required a good deal of 
research, and he hoped a man would be appointed to enquire into 
that in the future. He had seen anophelines in the overflow from 
factories, but they didn’t like it. 
Mr. Harrison said that he would like to know what Dr, Lucy 
thought about mosquito-proof lines and the leaving of ravines in 
blukar for the prevention of malaria. 
Dr. Lucy replied that as regards mosquito-proof lines he knew 
of two or three estates which had attempted it. Many years ago 
mosquito-proof hospitals were started i^ Negri Sembilam There 
was not the slightest doubt that it did some good, but there was 
another side to the question. There was immense difficulty in 
