'la c. 



E.S Q 



2 '^ -^ 



24000 



22 000 



20000 



13000 



16 000 



14 000 



12000 



10000 



8000 



6000 



4 000 



2 000 



Chart 3. Diarrhoea deaths and flies in Manchester in 1904. 





E.s 'a ^ 



o 



CO — <N 



— diarrhoea deaths 



Chart 4. Diarrhoea deaths and flies in Manchester in 1906. 



