Inactivation of Bacteria by Ultra-violet Radiation

Radiation from the sun has different effects upon living organisms. It has been found, for instance, that ultra-violet rays of a certain wavelength present in the radiation from the sun stop the multiplication of bacteria and other micro-organisms. Good use can be made of this, without having to depend upon sunlight, by employing a low-pressure, mercury-vapour lamp emitting rays which have a specifically disinfecting power exceeding by far that of sunlight. This lamp presents good possibilities for the solution of some problems of hygiene and for the sterilisation in processing foodstuffs and medicaments. The fact that millions of pounds worth of foodstuffs are spoiled every year through bacterial action shows how important it is that the growth of these micro-organisms should be checked also in this field.