popularity of photography with a rising middle class, which wanted but could not afford
oil portraits, coincided with the birth of this new pet culture.
Among the first kinds
of photos available on a commercial scale was the daguerreotype, a direct positive
made in the camera on very thin silver foil laid over a copper sheet. The photo
was like a mirror, and depending on the angle from which it was viewed, the color of
the surface reflected into it, changing it from a negative to a positive. Because of their extreme frailty, these one-of-a-kind
pictures were mounted under glass and set inside a hinged case conveniently sized to
be carried on one's person.
daguerreotype, ca.1850. Some of these early photos were tinted with pigments to give
the subject a more lifelike quality.