S S White Light for the Head Rest. Fig. 150, page 347, 'Dental Electricity' by Levitt E Custer, 1901.

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: S S White Light for the Head Rest. Fig. 150, page 347, 'Dental Electricity' by Levitt E Custer, 1901. Wellcome Collection. Source: Wellcome Collection.