184 GNATS OR MOSQUITOES — CHAPTER VIII 



untoward influence of canal irrigation on the public health 

 through the concomitant increase of malarial disease. The 

 matter has been the subject of several special investigations, 

 and as a matter of fact has been fully admitted alike by the 

 profession and the Indian Government long before we had 

 any exact knowledge of the way in which irrigation is 

 responsible for such evil effects. 



In some cases these effects have been so serious as to 

 raise the question of the advisability of abandoning the 

 system ; but these have occurred mainly in situations where 

 old native canals have been utilised, and in which the 

 alignment contravenes the principles that will be explained 

 below ; but it may be at once admitted that no suggestion 

 involving the prohibition, or even restriction of irrigation 

 will be considered worthy of serious consideration by practical 

 men. 



Starvation is a worse disease to bear than malarial fever, 

 and over much of the irrigated area, the ver}^ existence of 

 the population is dependent upon irrigated crops. In much 

 of the Punjab and Eajputana, and the whole of Sind, the 

 natural rainfall is so small that, but for irrigation from 

 canals or wells, the whole country would be an uninhabit- 

 able desert ; and the entire prosperity of the country and 

 the prevention of famine depend entirely on the energetic 

 extension of canals. 



Though admittedly, as weJaave seen, no unmixed blessing, 

 irrigation is in such places a necessary postulate to the 

 existence of any population at all, whether fever stricken or 

 healthy, and the question resolves itself merely into how 

 the malarious influences of canals can best be prevented, or 

 at least minimised. 



Irrigation is so little needed in Europe, that in order to 

 convey to those who have not seen it in practice, why and 

 how far it favours the spread of malarial disease, some few 

 words of explanation as to how this form of cultivation is 

 carried out are necessary. In the greater part of Europe, 

 the natural surface soil is rather too wet than too dry for 

 the farmer's purposes, and his efforts at improvement 

 naturally take the form of surface and subsoil drainage, and 



