The physharmonica looked similar to the hand harmonium still in use in India today, with a piano-style keyboard.
Smaller examples of this type of instrument rested on the left arm, and were played with the right hand.
A newspaper advert of 14 April 1821 in the "Allgemeine Musikalische Zeitung" says: "The master also makes very small versions which rest comfortably on the left arm, and which the right hand plays.
Similar early instruments, built in France, looked somewhat like an oversized modern piano-accordion, but were placed, like pianos, on a stand so one could use both hands on the keyboard.
One such instrument, made by "Busson Brevete" (Paris) in 1880, can be seen in the Vienna Technical Museum (ref.