the appearance of this trademark doesn't look quite like that shown in the books, and made me wonder if there'd been a subsequent slightly re-modeled version of the mark. This one is quite sharp so not, I don't think, a worn or damaged mark (it's on the bottom of the inside).
Am I correct in saying this trademark belonged to John Derbyshire, rather than James - also is it true that the company ceased completely somewhere in the late 1890's - and is it possible to tell approximately when these salts might have been produced?
I very rarely see pieces from Derbyshire - so assume they made little in comparison with other factories. I think these are in better than average condition for their age, although some wear on the extremities and base.
Thanks for looking.