THE CONTROL OF FLIES IN THE EGYPTIAN CAMPAIGN. 299 



Near by a 300-gallon tank was erected, and this was filled with, water daily. A 

 rough working emulsion, made with crude tar oil (bought very cheaply locally) and 

 soft soap, was mixed in the tank. Green oil was used when available. In the late 

 afternoon, the surface of the heap which had been used that day was thoroughly 

 drenched with this crude emulsion, at the rate of 1 gal. per square yard, with 

 watering cans. It was then covered with large pieces of sacking which had been 

 sewn together. This covering was left on during the following day, when the 

 adjoining heap was used, and then treated in the same way and so on, on alternate 

 days. 



When the writer arrived at this large camp, there was a tremendous number of 

 flies, and during the first few days they came in hordes to these dumps from breeding 

 places not vet dealt with, being carried from the camp on the loads of manure, the 

 men's backs and on the horses. A number of oil-drums were placed round the heaps 

 as shown in fig. 1. These were turned upside down and the bottoms made concave 

 like saucers. Early every morning a solution of 1 per cent, sodium arsenite in water 

 containing 12 per cent, glycerine and 5 per cent, sugar was poured on these drums. 

 The flies collected in masses and were killed in enormous numbers, and at the end of 

 a few days hardly any remained, the treatment of the manure preventing further 

 breeding in it. 



The addition of 80 G.S. wagon-loads of manure and burnt refuse daily soon 

 increased the size of the heaps. The labourers raked the heaps flat and square and 

 wagons used to pull up on the top of the heap at one end and when unloaded went off 

 at the other end. This helped to pack the heaps very tightly. These two dumps 

 lasted for four weeks, being at that time about 5 feet high. New dumps were then 

 started. The sacking cover over the heap was found unnecessary, and as a matter of 

 fact, owing to the great heat of the sun and fermentation heat, or an accident, one 

 cover took fire. 



The removal of all burnt refuse from the camp to the dump did away with other 

 breeding places in the camp, and there was a very appreciable decrease in the 

 numbers of flies after a few days. 



(2). Incineration of horse-manure. — It was not possible to carry out the method 

 described above with mobile units out on the desert, owing to the scattered camps 

 and the difficulty of transport. Under these conditions, incineration of the horse- 

 manure was tried. Each unit was made responsible for burning its own manure. 

 Incinerators were made of sheets of corrugated iron of the open brazier type, or of 

 biscuit tins filled with sand, with tibbin-bale wire as fire-bars. Owing to the large 

 amount of sand mixed with the manure, it was necessary to sift it before putting it 

 into the incinerator. Wire mesh screens were provided for units, and the siftings, 

 which contained a quantity of pulverised manure, were put into a deep pit and 

 liberally treated daily with crude tar oil. This is an important point, for if siftings 

 are neglected, they afford a very satisfactory breeding ground for flies. The writer 

 has found untreated siftings literally seething with fly maggots. Another important 

 point is to ensure that each day's manure is thoroughly disposed of and not left on 

 the ground. If possible, it is well to have a hard platform made of galvanized iron 

 on which to put the manure. Otherwise, a little of the manure may be left on the 



