CASSELL & CO LTD Cassell & Co issued some cards in October to December1894 and these were printed by Dennis with his very distinctive "Dennis Thin" lettering style on the address side. Cassell's interest in cards only resurfaced again in the early 1900's , when the postcard boom really took off.
Possible research note: I guess that these cards were given away as inserts in one of the Cassell magazines. The biggest of these by far was "Cassell's Family Magazine". It would be interesting to see this magazine for September and October 1894, to check for free promotional cards. There is also the possibility of finding Dennis printing work for this magazine?