Seabury & Johnson
The firm of Seabury & Johnson was formed around 1874 to produce and market Benson's Capcine Porous Plasters. Private die stamps for the product, with their depiction of the Good Samaritan, did not appear until 1880. They continued to be issued until May 1, 1883. 2,938,320 were printed, all on watermarked paper.
The term "Porous" in connection with medicinal plasters had been copyrighted by B. Brandreth, and a lawsuit was settled against Seabury & Johnson shortly after the stamp appeared. Many copies of their stamp have the word obliterated either by a printed bar or a pen mark. This variety is given a separate catalog listing.
There is no information on the lake variety other than the supposition that only one sheet was delivered. It may have been a trial or an error. Obliteration of the word "Porous" indicates that it was prepared for use.
This cancel on a general issue proprietary stamp is believed to have been used by Seabury and Johnson.
Around 1885 Robert Johnson left Seabury & Johnson and went into business with his brother under the name Johnson & Johnson. This firm took over Seabury & Johnson in 1896 but continued to operate it as a separate unit, as can be seen in this 1898 cover. Johnson & Johnson, of course, is still active today.