Original Hanau sunlamp, Modell Bach
ARC-DISCHARGE-LAMPS
Where the carbon arc lamp became the
first electric light source for therapeutic
use, the arc discharge lamp would
become the most important one. The first
usable arc discharge lamps capable for
medical treatment appeared at the
beginning of the 20th century as a
spin-off from the search for gas
discharge lamps for illumination purposes.
They were low-pressure mercury vapour
arc discharge lamps that, due to their
greenish-blue colour and relatively low
light production, were of little use for
illumination. The lamps produced a
relatively high amount of ultraviolet radiation however, which made them suitable for
the treatment of certain skin diseases. From 1908 on, high-pressure mercury vapour
arc discharge lamps with a much higher light production appeared on the market. In
order to withstand the higher temperature and pressure, these lamps were made of
quartz glass. This glass passed a great deal of the ultraviolet radiation. For domestic
applications this happened to be a drawback but it made the lamps suitable for the
manufacturing of sunlamps like the Original Hanau Modell Bach on display here.
The ultraviolet production of mercury vapour arc discharge lamps exceeded that of
carbon arc lamps significantly, allowing for new and more effective methods of
treatment. In particular for the treatment of rachitis or rickets, the high-pressure arc
discharge lamps have proven to be very effective.
