PREVENTION OF CHOLERA. • •? The following' observations on the "Memorandum of a plan of united action in the case of an epidemic ol Cholera," Which has been recently issued in the name of the Metropolitan Medical Officers of Health, are submitted to that body by a professional confrere, who takes a deep interest in sanitary economy, in the hope that they will Inreceived in the same spirit in which they are offered, namely, the desire that the recommendations authoritatively made to the public on this most important subject, should be an complete, and at the same time, as practical as possible. I.— Water.— Page 4. The statement that the " sediment is the most dangerous part of foul water," would seem to require qualification. Sediment of organic origin is undoubtedly very prejudicial to health; but sediment consisting' of inorganic matter is coo* siderably less deleterious than organic impurities in solution. The late Dr. R. D. Thomson, who was no mean authority on Water, had a very bad opinion of the surface pump- water oi London, notwithstanding its remarkably clear and sparkling appearance, because he found it to be loaded with soluble matter of organic origin. Some notice, under this head, of the means of freeing water from organic contaminations held limes and (jrazette or April last, is wortny or attention. " Purification or Water. — Another way in which water may b purified, probably well known to most of our readers, is that of Mr Condy. Solution of permanganate of potash and other bases [Condy' Fluid] when added to water soon oxidises organic matters, sulphurette( hydrogen, and other oxidisable bodies which may undesirably be presen iv water. The quantity necessary for the purpose is so exceedingly smal that the alkali introduced into the water is of no importance, 'while th manganese is converted into hydrated peroxide of manganese, whip' nmdually settles down, or may be removed by filtration. The perman ganate should be added to the water in as large a quantity as the wate can deprive of its pink colour on standing for two or three hours aft<* it has been introduced." II. — Against the Spread of Cholera. — Page 0. "c. Sprinkling the floor with chloride of lime." Would it not be better to recommend some other disinfectant for this purpose? Chloride of lime, even when in solution, is extremely ill-adapted for sprinkling the floor of inhabited rooms, and especially so when they happen to be carpeted. The insupportable odour of hypochlorous acid gas, when rapidly evolved, must of itself, in many cases, prevent the adoption of the means recommended. Mention ought, under this head, to be made of the gradual diffusion in the air of pure chlorine gas, slowly generated by Professor Stone's, or some other easy method. The diffusion of liquid disinfectants by means of the " spray-producer," or " atomiser," which is an admirable way of acting on the air of over-heated close rooms, might also be touched on with advantage. " r>. No one should take food in the sick chamber : certainly not without washing the hands." Would it not be well to recommend the addition of some efficient but innocent lll.— Disinfection and Disinfectants. — Page 7. " For the disinfection of the discharges from the body solution of chloride of iron or chloride of zinc is the mos powerful." Would it not be better to specify, for this purpose some disinfectant which can be recommended for othe objects? Any other would be quite as good as the abovi metallic chlorides, whose chemical constitution causes thei action to be limited to a small number of bodies. To requir< the use of a variety of disinfectants, is equivalent to raising difficulties, and, to that extent, must prevent the adoptioi of some of the measures recommended. "Chloride of lime in the proportion of a tea-cupful tv ; gallon of water." Directions for making the solution or milk of chloride of lime ought to be given. The only good way in to begin by making- a paste by the addition of a small quantity of water to the chloride, and then to thin the mixture b\ gradually adding the rest of the water. "Linen should be boiled in water, or plunged into boiling water." This might do more harm than good, unless the articles had been previously treated with cold water containing a good disinfectant. Suggestions for Handbills.— Page 12. "The chief disinfectants are chloride of lime, Burnett's* Liquid Solution of Chloride of Iron, and Condy's Fluid." Thus to class together those four substances can hardly fail to give rise to disappointment. Burnett's Fluid and Solution of Chloride of Iron have nothing whatever in common with chloride of lime and Condy's Fluid. Taking everything ii it <> none ; having 1 no smell of its own, it is never, under any circumstances, offensive. When diffused in the air by means of the " spray-producer," it acts on the atmosphere as rapidly as any of the gaseous disinfectants. Condy's Fluid, moreover, furnishes a ready means of producing pure chlorine gas as well as ozone ; for by the addition to it of muriatic acid, the former is slowly disengaged, while by that of sulphuric acid, ozone is gradually evolved. » There are not wanting reasons for thinking that this aration, which principally consists of permanganate <>l 3h in solution, by supplying a ready means of administerdisinfectants internally, may be found of use as an antidote to the choleraic poison. The subjoined table, exliting the results obtained in Madras from Oondy's Fluid, compared with those of cither methods of treatment, would m to indicate the possession by the permanganates of larkable antidotal properties. The combination of diluted idy's Fluid with precipated chalk might probably be found extremely valuable mixture for arresting premonitor3' Authority. « Deaths, centage Treatment. J ot cases. c , .? oi deaths. Mr. Eyezard. if- I* 53 Condy's Fluid, internally, stimulants, and nutrition. Dr. Mackay .600 Ditto. Dr. Doyle . 46 15 32"6 Ditto, with astringents X [faulty cdmbinationi. ry . 35 15 42-8 (Not known), [organ. 131 67 511 Ditto, oward B. Montgomery in Medical Times Sf Gazette, March 10, 1866.