146 



are given fully. Detailed instructions for dipping sheep for the 

 control of this Hippoboscid are given, and the most useful apparatus 

 is described. The various dipping mixtures include coal-tar-creosote, 

 cresol, nicotine, and lime-sulphur-arsenic dip ; the choice of the dip 

 to be used should depend upon the conditions under which it is to be 

 employed. The first three mentioned are all sold under various trade 

 names. The hme-sulphur-arsenic dip is the only home-made mixture 

 that has proved efficacious ; it is made by mixing standard strength 

 lime-sulphur with one-half standard strength arsenical dip ; full 

 chrections are given for the preparation of the mixture. The con- 

 struction of the best kinds of dipping vats is described, with diagrams 

 and illustrations. 



Jackson (A. C.) & Lefroy (H. M.). Some Fly Poisons for Outdoor 

 and Hospital Use. — Bull. Entom. Research, London, vii, no. 4, 

 May 1917, pp. 327-334. 



Solutions of sodium arsenite and sugar have frequently been 

 employed as outdoor fly poisons, and were used with good results in 

 Mesopotamia in 191(3. The disadvantage of using these solutions is 

 that they are poisonous in themselves and remain poisonous when 

 thrown away or dried on sand or soil. Formaldehyde, which is the 

 only other generally known poison, is exceedingly variable, in its 

 action and is too volatile for outdoor use in a hot chmate. The authors 

 therefore undertook a series of experiments with other substances 

 used as fly poisons, usually at a strength of 2 per cent, by weight with 

 a 20 per cent, sugar solution. A complete list of the substances tested 

 is given, these being divided into three classes ; (1) those that kill 

 quickly, (2) those that killed on the second day and (3) those that 

 failed at 2 per cent, strength. WTiile these experiments are not 

 conclusive, it is evident from the results that there are substances 

 other than arsenic that will kill flies and, while these may not be 

 effective in areas where flies have abundant shelter and food as in 

 France and England, they may be very effective as outdoor poisons 

 in Mesopotamia and Egypt. It seems probable that some of the 

 fluorides, iodates and salicylates of sodium, potassium and ammonium, 

 iron perchloride and some other substances may replace sodium 

 arsenite in these circumstances, which would be a great advantage 

 owing to their being less poisonous and their residues forming non- 

 poisonous compounds. These chemicals might be tested in areas 

 where flies are important and might be used in distant places where 

 sodium arsenite cannot be obtained. It seems evident that many 

 common drugs and substances, not known to be fly poisons, may be 

 so under conditions where flies are really abundant, and where they 

 will probably take the substances offered with avidity, as sodium 

 arsenite is taken in Mesopotamia, and it is suggested that, if the known 

 poisons should not be available, the medical officer in such localities 

 should try anything else that is obtainable. In hospitals particularly 

 there will probably be a use for these poisons, where any of the above- 

 named substances, used at 1 per cent, in sugar solution, are neither 

 dangerous nor offensive. 



