Are salt cellars usually sold in pairs?

Pairs dominate. "Pair" is the commonest word in titles across the archive, and sets of four turn up often enough to count as a recognised format. Singles exist, and so do larger groups. One set of five and one set of six sit at the very top of the range.

Do they come with spoons?

Some do. Spoons are named in 21 of 150 titles, often alongside a fitted case. The salt spoon is the small matching server; the shovel is the flat-bladed variant of it. Cased sets are where the spoons most often survive together with the salts.

What are the blue glass liners for?

The liner is a glass insert that keeps salt off the silver. Cobalt, blue and cranberry are the colours named in listings. Glass is mentioned in ten of the hundred and fifty titles, so a liner is a feature to look for in the description rather than something every salt carries.

Is everything in this category solid silver?

No. Sterling and solid are the words used in a good share of titles, but silver plate is a steady presence, mostly plated cruet stands and plated salts with coloured liners. French silver-mounted etched glass also appears. Plated pieces sit lower in the range, except for the elaborate figural cruets.

How old are the earliest ones on Sellingantiques?

The dealer-entered dates run from 1750 to 1960. The earliest hallmark quoted in a title is 1738, on a Georgian pair, with a set of trencher salts marked 1743 close behind. Victorian is the largest dated group, then Georgian, then the 1930s. Twentieth-century material is well represented, including Art Deco condiment sets and a handful of 1960s pieces.

Which assay towns turn up on them?

London appears in twelve titles and Birmingham in eight, making them the two most commonly named. Sheffield, Chester and Edinburgh each appear only once or twice, so those marks are the scarce ones in this category.