Transmissioii 47 



addition to the series of pipes supplying Cairo with filtered water, 

 it appears that there is a second system carrying to the numerous 

 gardens of Cairo unfiltered water drawn direct from the Nile in the 

 neighbourhood of the Kasr Nil bridge, a spot where, in recent years, 

 numbers of European troops have, while bathing, become infected 

 shortly after their arrival in Egypt. It is well known that the 

 children, even of the better-class Egyptians, are allowed to runabout 

 in the privacy of their own courtyards in a state of semi-nudity 

 during the summer months, and are thus continually exposed to the 

 risk of infection from the hose used in the garden or stable. The 

 lower classes probably derive their infection from the same source, 

 although under different circumstances. To them water is a dear 

 commodity in Cairo. There is no free supply. In the poorer 

 quarters one frequently sees water being hawked about in large 

 skins, and there is the standing inducement to the middleman to 

 increase his margin of profit by arranging to draw his stock, 

 possibly surreptitiously through a friendly gardener, from the un- 

 filtered supply for which the water companies make a lower charge. 

 At Ismailia there is a dual supply of filtered and unfiltered water 

 into the houses, the latter being laid on to the bathroom and kitchen 

 and supplied at a lower rate. A standard pipe from the unfiltered 

 supply in Cairo is shown in fig. 22 from a photograph taken in the 

 courtyard of one of the Government offices. 



Conclusions Contrasted. 



CoNXLUsioxs (1) ^'1 transient collections of water, such as 



BASED ON those resulting from occasional showers of rain, 



THE Looss road waterings and domestic waste, are dangerous 



Hypothesis, ^f f^.^g^^j^. contaminated. 



(2) Large bodies of water, such as the Nile, canals, marshes 

 and birkets, are little liable to be infective. 



(3) All water in a given area would automatically become safe 

 in thirty hours if the native infected population were removed. 



(4) Infected troops would be liable to reinfect themselves, to 

 spread the disease among other troops, and to convey the disease to 

 any part of the world. 



(5) Infection only takes place through the skin. 



(6) Infection in towns is due to contact with recently con- 

 taminated moist earth or water. 



(7) Eradication depends upon education and complete sanitary 

 control throughout the country. The sustained co-operation of the 

 affected individual is essential. 



