4 INTRODUCTION 



homely urban mosquito with disease was not realised. 

 The text-book already quoted states that Empedocles 

 of Agrigentum is said to have drained a marsh, and 

 made Selinus in Sicily healthy about 550 years B.C. 

 Strabo (first century B.C.) remarks that Alexandria 

 was free from marsh fever in his time (Alexandria now 

 is surrounded by very salt sea- water marshes in which 

 malaria-carrying mosquitos do not breed). I have 

 mentioned elsewhere the possibility that marsh and 

 mosquito-carried disease may have accounted partly 

 for the downfall of the ancient empires of Egypt and 

 Mesopotamia, caused by the over-irrigation and want 

 of drainage in those river-dependent countries ; the 

 land of the delta of the Nile is now becoming water- 

 logged, owing to deficient drainage and excessive 

 irrigation under the present-day civilisation. Pro- 

 fessor Ross and Mr. Jones have already suggested, 

 and collected considerable evidence to prove, that 

 malaria assisted in the decadence of Greece. The 

 Cretans, Greeks, and Romans had some wonderful 

 agricultural drainage arrangements, remains of which 

 may be still seen in some places ; and there is a re- 

 markable old masonry drain under the city of Bey- 

 rout, which must have existed for centuries. Ancient 

 civilisations probably realised the danger of marshes, 

 swamps, and even urban stagnant water-collections, 

 but their remedies were never very successful, because 

 the actual cause of the danger mosquitos was not 

 understood, and was not revealed until the end of 

 the nineteenth century. 



According to Mr. P. V. Theobald, the author of 



