SUPPLEMENT TO THE HONGKONG WEEKLY PRESS.
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recognise them either in the larval s‘age or iu the adult stage. The individual names are of no importance from the present point of view, and they are not labelled in detail.
I may mention in passing that the two genera prevail in Hongkong in very unequal proportions, fortunately from the point of view of malaria. That I might determime their relative prevalouce, I examined during the twelve months, Oct. 1, 1900, to Sept. 30, 1901, $1,390 mosquitoes, supplied to me in weekly instalments from all parts of the island and the New Territory though the kindness of the police; and I found that 1,169, i.e. 3.7quito was present everywhere, and it was proposed per cent., were anopheles of 3 species, and that something should be done to get rid of the 30,221, ¿,e. 96.3 per cent., were culex of 12 insect. The steps recommended were taken, species. Of the three species of anopheles, and 200 to 250 Indian troops were sent up by These men were Anopheles Sinensis is a widely distributed form. Major-General Gascoigne. It breeds on the low levels and among the rice engaged for months in cutting down brushwood, fields. The other two, Anopheles Maculatus draining nullahs, and doing everything that and Anopheles Minimus, were named and science could devise for the purpose of ridding described from specimens which I sent the locality of mosquitoes. The curious thing to the British Museum through Dr. Rees was that these Indian troops, who were exposed of the London Tropical School. They have to all the ravages of the mosquitoes at ni ht, for not thus far been found elsewhere than in they were encamped there, did not suffer at When the operations were finished the Hongkong. They breed in the ravines all all over the Colony, wherever the water is white troops were again sent up to the Sana- for any cause prevented from running freely.] torium and no disease was to be found there, In most exhibitions you are particularly request- but when part of the King's Own Regiment, ed not to touch. In this demonstration you are took up occupation of the Sanatorium such a invited to touch and handle everything. The great amount of malarial fever declared itself flasks and cubes of mosquitoes and larvae are that the men had to be withdrawn. Dealing arranged in pairs, one containing culex and the with the New Territory, where they had other anopheles, for examination side by side. had large experience of malarial fever, and The males in both genera are readily distin- where a number of meu had been lost during new Police Stations, guished by the abundantly feathered condition the building of the of the palps and antennae. With the exception His Excellency said that at Sai Kun the of the station was delayed for a of probably only Stegomyia, of which I spoke erection in reference to yellow fever, all male mosquitoes long time because of the number of coolies that;
were down with the disease; six of whom and one are vegeta ian in their habits.
contractor had died, According to the theory propounded by Dr. Thomson, the mosqui- toes must bare become infected from the turn should have infected coolies, and in the healthy men who afterwards inhabited station, But they did not, and the
After dealing there the matter remained. with the means adopted for the fighting of malaria in the New Territory, consisting chiefly in the proper use of prophylactics, which were attended with beneficial results, His Excellency concluded by saying that in all such theories he was sure one could always find some fact that could not be got over, and he was by no means sure there were not other agencies besides the anopheles mosquito for the propagation of malarial ferer. (Applause.)
The lecturer, who was loudly applauded when he concluded, was succeeded on the platform by H.E. THE GOVERNOR, who said that whilst some of the gentlemen present, especially the officers of the Royal Army Medical Corps, were making up their minds to say something, he proposed to make a few observations on what he thought was the most interesting lecture delivered in Hongkong for a number of years. The question of the influence of the anopheles mesquito in spreading malaria was a most im- portant one, and there was nothing in the life history of the mosquito, anopheles and culex. that had not been clearly expounded by Dr. Thomson, in fact so clearly bad that history been detailed that there was not a mosquito in the Colony but would lie uneasily in his bed that night. (Laughter.) The question, however, was not solely the connection existing between the mosquito and malaria, but whether the mosquito was the sole means of propagating the the disease. That that charge could be laid
[December 20, 1902. - -
in which Dr. Thomson in his paper had traced the connection between malaria and mosquitoes.
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against the mosquito did not seem probable from the experience of the troops occupying the
It was generally held now in Sanatorium at the Peak two years ago. Mala- rial fever attacked them, and so badly that they the profession that malaria fever was a conta...... had to be removed to the barracks on the lower gious disease, and that the contagion was Dr. Young, an officer of the Indian transmitted to man by the bite of an in- levels. Medical Staff, who was here at the time of the fected anopheles; indeed a saying of Dr. no anopheles, North China Expedition, and who, like Dr. Manson, a great authority, was,
The speaker believed the time ❤ Thomson, was an enthusiast in the investigacion no malaria.'
an would soon come when those suffering from this of this most interesting question, made examination of the surroundings of the Sana- disease would have to be isolated, that was to torium, and found them to be swarming with say, be treated in the same way as we would a mosquitoes. He found that the anopheles mos-person suffering from smallpox, This method of isolating those suffering from that form of malarial fever, in which crescents were formed in the blood, would, he thought, prove more efficacious than attempting to rid a place like this of mosquitoes. There were so many crevices in the hillsides of a place configurated like Hongkong, where standing water can collect and where anopheles breed, that he feared it would be a matter of impossibility to
Dr. Thomson's remarks :: exterminate them. concerning the likelihood of yellow fever breaking out here as the result of the establish- ment of this New Steamship Company were in his opinion of too alarmist a nature, and he thonght he was correct in stating that yellow fever is not endemic beyond ten degrees north or south of the equator. This being so, even if yellow fever were introduced, it would not secure a foothold here. There were one or two practical points which might prove of interest, one being that he found last year in certain experiments which he conducted that Jeyes' fluid was one of the most effectual larvicides, one teaspoonful to 14 gallons of water containing larvæ killed them all within five minutes. Therefore if residents would see that Jeyas fluid was added, say daily, in these proportions to any collections of standing water on their premises, much would be done in the way of destroying these insects. Another was that by burning the unexpanded beads of certain species of chrysanthemums mosquitoes cou'd be des- troyed. In Italy there was a powder sold under the name of zanzolin, which consisted of the powdered unexpanded flowers of chry- santhemums with the addition of valerian root, the fumes given off by burning this powder. were used in destroying mosquitoes inside out- houses, &c. By cultivating chrysanthemums on a large scale, and they grow well here, it was very probable that the malarious place itself will produce that which will rid it of the mosquitoes which infest it. These few practical points, concladed Dr. Atkinson, he had men- Following Colonel BROWN, R.E., who spoke tioned as he deemed them worthy of interest.
A hearty vote of thanks was accorded the of his observations with regard to the San-
Dr.
ATKINSON, Principal Civil | lecturer, on the motion of H.E. the GOVERNOR, atorium, Medical Officer, said they had listened with and the proceedings then terminated. much attention to the able and clear way
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