Cartes de Visite originated in France but became a popular and fashionable fad throughout Europe during the Victorian era. As a result, there are many collectors of these accessible (but slightly wierd) photographic portraits of middle class Victorians, and quite a lot of information is available for the mildly interested.
For instance, the John E. Palmer elegantly scripted upon this card was one of two photographer brothers from Devon, and along with William Eastman Palmer (and five of his seven sons) who appeared to dominate the south west market.
Much more information can be found in the following links:
Many thanks to my friend Pete who has kindly allowed me to feature them here.