108 THE STORY OF THE BACTERIA. 



therefore to be thoroughly boiled before it is 

 fed to infants and young children, and very 

 simple and inexpensive forms of apparatus for 

 this purpose have been devised and can be 

 recommended by any well informed physician. 



As the germs of various diseases may be 

 floating in the air, especially in densely popu- 

 lated regions, all fruits, vegetables, and salads 

 ought to be thoroughly washed before they 

 are eaten, unless they are to be cooked. The 

 exposure of such articles of food on the side- 

 walks in cities, as is so often done, is a most 

 reprehensible practice, and this alone should 

 be enough to decide the householder to dis- 

 pense with the supplies of any dealer who per- 

 sists in it. 



There is no doubt that the germs of typhoid 

 fever, and, when it is prevalent, those of Asiatic 

 cholera, are conveyed from one to another by 

 means of food on which in some way the 

 germs from the discharges of sick persons 

 have lodged. This is of course most apt to 

 occur among the poorer classes in large towns 

 whose market-stalls are the gutters, and whose 

 living-rooms, alike for sick and well, may 



