I2O 



of infantile or summer diarrhoea and typhoid fever. It is, 

 therefore, of prime importance to give the Insect no oppor- 

 tunities for breeding and thereby providing a check upon 

 its abundance. All accumulations of manure and refuse 

 should be removed at least once a fortnight, or more often 

 if possible. The adoption of closed ash-bins excludes the 

 access of the Flies to their contents, and are most effective 

 in this respect. Accumulations of farm manure provide 

 nutriment for enormous numbers of House Fly maggots. 

 Experiments on a large scale are being conducted both in 

 this country and America for the purpose of rendering 

 manure heaps repellant to the Flies and their maggots 

 and, at the same time, still retaining their valuable fer- 

 tilising properties. When troublesome in houses the House 

 Fly can be readily poisoned by using one teaspoon ful of 

 formalin added to a teacup ful of water poured into a 

 soup plate. The mixture should be sweetened with a little 

 sugar or should contain about 25 per cent, of milk. If 

 placed at night large numbers of the Flies will partake 

 of it in the early morning and are poisoned thereby. The 

 mixture also has the advantage of being too weak to be 

 harmful to human beings or domestic animals. 



