Vol. XII. No. 294. 



THE AGRICULTURAL NEWS 



247 



VETERINARY NOTES. 



DISINFECTANTS AND DISINFECTION. 



A useful account of some common disinfectants and 

 the ways of employing them is given in the Ai/riculturiil 

 Journal of the Union of Sauth Afrioi, for May 1913. The 

 writer, W. Jowett, F.RC.V.S . of the Veterinary Division 

 of the Department of Agriculture, commences by referring 

 to the importance of destroying carcases of diseased animals, 

 either hy thorough burial, or by cremation. In regard to 

 the burial of animal.s that have died from such a disease 

 as anthrax, it is noted that care must be taken to prevent 

 soiling the ground with any discharges from the dead body. 



METHODS OF CREMATION. 



In connexion with cremation, the writer advocates the 

 following procedure; A trench about 9 or 10 feet long, 

 5 feet wide and 5 feet deep should be almost filled with 

 wood arranged cross-wise and moistened with kerosene The 

 importance of ventilation to ensure complete combustion in 

 the process of cremation is strongly emphasized, and in this 

 connexion, reference is further made to the ingenious method 

 of cremating carcasses originated by .VJajur-General Smith. 

 Briefly it consists in digging two trenches in the form of 

 a cross, over which are placed two iron rails. The fuel is 

 put on the rails, which bridge the centre of the cross, and the 

 carcass is placed on the top of this. In some cases it is 

 desirable to dismember the body before the cremation. 



GASEOIIS DISINFECTANTS. 



Proceeding to discuss the employment of common dis- 

 infectants in the prevention of diseases, mention is made 

 first of sulphur dioxide gas, which, as a fumigation agent, 

 is useful for destroying rats, flies, Heas and vnrious biting 

 flies which may serve as intermediaries and propagators of 

 diseases. In regard to the generation of this gas, it is noted 

 that the sulphur should be moistened with spirit in order to 

 favour combustion About .5 lb. of sulphur may conveniently 

 be burned for every 1,000 cubic feet of space in the building 

 to be disinfected. It is pointed out that two disadvantages 

 of sulphur dioxide are that it bleaches colours and has only 

 a superficial action. 



The next disinfectant considered is formaldehyde, 

 a substance which has very powerful germicidal properties. 

 The gas can be i)repared from a whitish powder known as 

 as paraform, or the disinfectant, dissolved in water may 

 be simply sprayed. In employing the gas itself, the 

 most convenient method is to prepare it from formalin 

 by the action of potassium permanganate. It is recom- 

 mended that for every 1.000 cubic feet of air space, 

 20 oz. of formalin and 16i,' oz of potassium permanganate 

 crystals should be used. Before evolving the gas, the 

 walls must be sprayed with water, and doors and windows 

 made as air tight as possible. 



CHEMICAL .SOLUTIONS. 



Referring next to chemical solutions, the writer states 

 that it is always advisable to apply hot solutions in 

 preference to cold ones, owing to the greater germicidal 

 power of the former. It is strongly emphasized that before 

 disinfecting stable fixtures, harness, utensils, etc., a prelim- 

 inary cleansing with soap and boiling water is essential. 



Aliliough, in the next section, the different forms of 

 carbolic acid are recommended for use, cresol, or straw- 

 coloured carbolic acid is believed to be the cheapest, most 



satisfactory and useful disinfectant for general purposes 

 Crude carbolic acid, because of the oil it contains, is of 

 uncertain action. The interesting fact is noted that the 

 germicidal effect of carbolic acid is increased by the presence 

 of common salt, but that the presence of oil and grease 

 diminish the germicidal power. The carbolized oil at one time 

 so extensively employed by attendants on animals is now 

 known to possess little, if any, germicidal power. Lysol is 

 al.so recommended as a satisfactory disinfectant, particularly 

 for surgical purposes. It is rather expensive for common use. 



Observations are next given concerning the employment 

 of corrosive sublimate. Most of the di.sinfectants so far 

 described cannot be conveniently used in cowsheds or dairies 

 owing to their objectionable odour. Corrosive sublimate 

 requires cautious use because it appears to be harmless. It is 

 a white crystaline salt not readily soluble in water, and forms 

 an odourless, colourless solution which is extremely poisonous 

 and must be used for utensils only with the greatest care. 

 A solution I in 1,000 suffices for the destruction of non- 

 sporulating organisms in a few minutes. To kill spores, 

 a 1 in 500 solution may be employed for an hour or so. 



CHLORIDE OF LIME 



For the disinfection of cars, trucks and floors of stables, 

 etc, a fre.shly prepared solution of cliloride of lime (6 to 8 oz. 

 per gallon) may be used When fresh, chloride of lime is 

 a good general disinfectant and deodorant, but it is readily 

 attacked liy various kinds of organic matter. Although 

 chloride of lime has been used for disinfecting diseased excreta, 

 it is stated that cresol is more dependable for this purpose. 



DISINFECTION OF LE.^TIIER. 



The account of the routine of disinfection, given at the 

 end of the article under consideration, contains several facts 

 which may be noted briefly in this abstract. Infected 

 leather work and leather goods should not be steamed or 

 boiled or treated with forraalin. The best procedure is to 

 scrub them with soap and water, and then immerse them for 

 two hours in a bath of cresol. The disinfection of skins and 

 hides may be done by immersion for twenty four hours 

 in a bath of 2 per cent, cresol or in a solution of corrosive 

 sublimate ( 1 in 1,000) Formalin and steam cannot be used 

 because they injure skins. The substances recommended, 

 however, have no such destructive action. 



In preparing lime-wash and chloride of lime for disin- 

 fecting walls, light coats applied, are bet'er than heavy ones, 

 as the latter are apt to peal off'. It may be noted that 

 the addition of about .5 per cent, of common salt to lime- 

 wash will tend to render the latter more adherent. Glue 

 is sometimes used for the same purpose. 



An interesting article on milk production is published 

 in the Journal of Agriculture of New Zealand (.May 1.5, 

 1913). This deals principally with the effect of change 

 of pasture and feed on the yield of milk. It has been 

 demonstrated by means of tests that a complete change 

 for a dairy herd as well as for sheep is conducive to better 

 results: if the cow-paddock be divided into small areas so 

 that the animals may be continually moved on to clean 

 ground, the increased milk-yield soon compensates the 

 outlay in extra fencing. The same principle of change 

 applies to feeding in general, and the matter would seem to 

 be worthy of the careful attention of stock-owners in the 

 West Indies. 



