Anotlier mosquito, of the sub-family Panop- lites, has also been caught, but only in small numbers. Of Corethra three varieties were discovereil, one of which breeds largely in the Ross drinkifig water tank and is the only larva to be found there.
These Corethree appear to have no biting apparatus, and therefore can hardly l)e said to be carriers of infection. One variety has not hither- to been described, and appears to be a new one discovered by Mr. Lowis.
On the whole, mosquito brigades are of distinct benefit; for some unexplained reason they have not succeeded this season in Ross and Aberdeen, but in the other districts the results are encouraging. Undoubtedly the stations are much cleaner and the number of mosquitoeb- less, but they are far from being exterminated; they no longer flourish in the fire barrels or in the immediate vicinity of barracks, but except in very small or special areas, or where there is enthusiastic European supervision, these pests will remain and continue to carry infection.
2. The prevention of infection by the use of neU, etc.
At first sight this appears to be the remedy offering the best prospects. We know that a net will keep off mosquitoes, and we also know, from fifteen months' stea<ly observation in the Female Jail, that persons sleeping under a net have only one-fourth the risk of malaria that unprotected people have, and when attacked with fever are a shorter time in hospital. The cost, too, of mosquito netting is comparatively little. Why not then introduce it ?
The great drawback to netting is its inter- ference with ventilation. Even under an ordi- nary mosquito net the difference in the freshness of the air inside and outside is quite marked, and this is equally the case with a larger net containing twenty or thirty people. The women in the jail complain much of the heat under the net, and it is absolutely certain that if nets are to be taken into general use as malaria guards the amount of cubic space [)er head must be very considerably increased, for there is practi- cally no movement of air through the meshes of a thick net.
The question is of much importance owing to the prevalence of phthisis, and one is confronted by two precisely opposite problems. To check malaria in this way one must put up nets to exclude mosquitoes, and consequently seriously interfere with the air supply. On the other hand, to check phthisis, we must have better ventilation, more air and more supeificial space. Whid^ is the better ? I think the balance is in fevvmr of more space and more air, combined with meafiRires to be presently discussed.
3. The effective dosage of the whole popula- tion with quinine.
This procedure is strongly recommended by many authorities, more especially by the Italian observers and by Koch. The theory is that the
administration of one gramme of quinine daily for two successive days, and the repetition of this every week will check the occurrence of malaria by inhibiting the growth of parasites. The local opinion is against this theory, but qui- nine had never been given in sufficient!}' large doses, nor had the distribution been made on sufficiently systematic lines. Naturally, over a district conipiising 130 square miles of countr}, and populated by men of very varying occupa- tions, who cannot always be caught at meal or other parades, the issue of quinine regularly is a very difficult matter.
Major Anderson's experiments shewed that small doses of quinine such as 2^ to 5 grains daily had absolutely no effect on the malarial admis- sions of the Female Jail, but that the effects of large doses were more favourable. Longer obser- vation has confirme<l this view. Twenty grains of quinine twice weekly have halved the admis- sions for malaria, but the remedy is not a specific.
During the malarial outbreak last year, I directed that a further experiment should be made at Bindrabun, probably the most malarious place in the Settlement, but the results were most disappointing so far as this station goes.
One hundred and twenty men were taken and their names recorded. To the even numbera 20 grains of quinine were given on two successive days, to the odd numbera nothing. The results were as follows : —
 | A table should appear at this position in the text. See Help:Table for formatting instructions. |
Average Stay in hoapit&l. Quinine. No Quinine,
6-66 daya 5*60 daya
After August the special experiment waa diacMitinued.
In June last an attempt was made to ciieck the malaria by an is.sue of 10 grains of quinite to every convict on two sncces^ive days, repented weekly. With the help of the executive authori- ties diaries were arranged, and parades organised. Compounders accompanied by Petty Officers were sent round the districts and instructed. Each man hsd his route and times marked out for him, so that all C(»ncerned knew what arrangements to make. In the larger stations private servants, boatmen, and ( thers in special employ were attended to by travelling compounders, who visited the diflTerent houses and so avoided the inconvenience of such men having to attend |)ai-ade8 or hospital. This pro- phylactic issue lasted from June 16th tu Decem- ber 1st. Some details are appended.
Altogether 496,501 doses (each of 10 grains) were issued, and about 650 lbs. of quinine ex- pended. Over the whole period of five months t more than 80 per cent, of _the population wer^ IC
