There's not a lot of postal history information available on patent cancellations. There were many entrepreneurs inventing cancellation devices for the Post Office Department at this period of time. Perhaps the best reference source for these is still the APS Cyclopedia edited by Norona from back in 1933.
This card appears to exhibit a cancellation much like the Gaston patent types illustrated in the APS Cyclopedia. The cancellation and date stamp appear to be from separate devices and the patent killer is in a blue-green color.
Aside from the cancellation interest, the reverse side of the card is a dues notice for one of those early mutual benefit organizations, our life insurance forerunners. I don't know the history of these, but it appears that all members contributed monies to a fund regularly until their time came due, and the fund would pay a lump sum amount. The card lists the most recent members who died, along with ages and causes of death. It looks as though TB and Pneumonia were major killers of the time. Perhaps formal life insurance was not available or too expensive for the members of these organizations.
The December 5, 1881 is quite an early use for this postal card issue.
Place mouse on image to see the reverse side of the card.