KYJ,
I’m in the land of dial-up, so cannot access the book. A fuller was one who thickened cloth by stamping/beating it in water to which urine had been added. As a family name it is a variation on Walker and Tucker, also derived from the same trade. There is a good connection between mercury as a cure for syphilis (mixed with lard, external treatment) and the mad hatters – it was a French felt hatter who while undergoing mercury treatment produced the best felt. Thereafter mercury was added to the process (as an ingredient, not as a weight.) The “night silver” you mention is I think not mercury, and was in the form of an egg; it was “passed” down through families for several generations. Mercury could be precipitated out very easily, due to its high specific gravity.
To keep gun-related, the potassium nitrate (saltpetre) for early gunpowder also was collected from urine.
PeteM - Is honeycombing not a change in the metal structure? cast cannon suffered from it and I always believed it to occur around the touch-hole and breech areas. It is regularly mentioned in the Patrick O’Brien novels in relation to cannon.
K.
