DISEASE-GERMS. 179 



by the aid of the most powerful microscope and with all 

 the appliances of artificial light. * 



It is no wonder, says Dr. Fiirst, that infection should 

 spread, when we realise that the air of a sick-room is loaded 

 with germs so minute that hundreds may adhere to the 

 smallest particle of skin, that they may settle in the hair, on 

 clothes and books, may be carried away in numbers by the 

 flies and deposited on food or anything else upon which they 

 next alight, and, unless expelled by carbolic acid, may remain 

 for months in carpets, bedding, &c. Even a bright silver 

 spoon which has been used by a sick person will probably 

 have germs adhering to it until properly disinfected. 



People are more alive to the dangers of infection than 

 they were, and Dr. Fiirst mentions, as an instance of official 

 caution, that a telegram sent from Alexandria during the 

 last cholera epidemic, was detained twenty-four hours on the 

 way, to be properly fumigated ! 



But we must not regard even the bacteria as purely 

 useless or mischievous. " They are," says Dr. Tyndall, 

 " noxious, like many other things, only when out of their 

 proper place. In their place they exercise valuable and 

 useful functions as the burners and consumers of dead 

 matter, animal and vegetable. They are not all alike, and it 

 is restricted classes only that are dangerous to man. There 

 is no respite to our contact with the floating matter of the 

 air, and the wonder is, not that we should occasionally suffer 

 from its presence, but that so small a portion, and that 

 diffused over wide areas, should be deadly to man." 



* Thirty thousand million cholera -bacteria, or comma-bacilli, as they 

 are called from their shape, occupy the space of a pin's head. 



