t64 



PROCEEDINGS OF SECTION I. 



result of Dr. Ross's campaign were a few drapers who had no longer 

 any sale for their stock of mosquito netting. 



Equal success attended the crusade in Khartoum. The first 

 of those model reports issued from the Wellcome Research Labora- 

 tories of the Gordon Memorial College recording the splendid work 

 of Dr. Andrew Balfour, the Director, contains an account of the 

 organisation of a mosquito brigade towards the end of 1903. Dr. 

 Balfour, having classified the species of mosquitoes found in 

 Khartoum and made a general survey of their breeding haunts, 

 suggested to Colonel Talbot, R.E., the formation of a mosquito 

 brigade on the lines laid down by Major Ross. Two intelligent 

 natives were trained to recognise under the laboratory assistant 

 mosquitoes, their eggs, larvae and pupte. Captain Rivers, the 

 acting S.M.O., provided the equipment with which the mosquitoes 

 were attacked in their larval stage. This was easily accomplished, 

 owing to the nature of their breeding places, classed as follows : — 



1. Wells, by far the most numerous and most largely 



infected. 



2. Sakia pits, both along the river bank and in certain 



gardens. 



3. Garden tanks, practically confined to the river front. 



4. Bath waste pits. 



5. Permanent garden pools, practically only found in the 



Palace Gardens. 



6. Zeers (native water filters). 



7. River pools — i.e., pools left in the banks by the falling 



Nile. 



8. Steamer holds, tanks, water-closet cisterns, and engine- 



rooms, also the holds of wood and other barges. 



9. Chance water collections as in old " sardals " or barges 



drawn up on the river bank, and from which speedy 

 evaporation was prevented. 



Fortunately, in Khartoum they had not to deal with any 

 swamps, ditches, permanent pools in the streets or near the houses, 

 empty cans, old bottles, broken crockery, or other receptacles con- 

 taining water for any length of time ; at least there were none 

 such in the season of 1903, when the rainfall dui-ing the summer 

 was trifling. Crude petroleum was used, not only because it was 

 cheaper, but because comparatively little of the well water is used 

 for drinking purposes, the native portion of the population pre- 

 ferring to use water direct from the Blue Nile. 



Latterly, as a considerable quantity of refined petroleum had 

 been stocked, a mixture of crude and refined was employed. The 

 former was found to be the more efficacious (as was the case also 

 in Port Said), as it formed a denser film and one which lasted 

 longer. 



The men constituting the brigade began every morning to 

 visit systematically all the water collections in the town, beginning 



