bitter o salt on 18 Aug 2007  •  Link

Epsom [Epsum] Salts be good for what ails the human, King or leveller, the horse or thy roses. Stories galore on its chemical make up. Named after the hamlet that supported a convent, known as Ebbisham, Ebesham or Epsham.
Found in the Domesday book as Ebesham, here derived from the Saxon words 'Ebbe' (to flow back) and 'ham' (a village). Then the tale of a princess named Ebba.
The village thrived on taking and training horses, on taking thy money and if thee felt a little pale under the collar, upon losing thy bet, sold thee a good dose of salts to compensate for thy bad luck.

bitter o salt on 18 Aug 2007  •  Link

N.B. other than Samuell the Epsum salt is in the OED for 100years later.

OED under salt:
Epsom-salt (colloq. -salts), originally the salt (chiefly composed of magnesium sulphate) obtained from this water; now the popular name of magnesium sulphate however prepared.

1770 tr. Cronstedt's Min. 137 This may be called English or Epsom salt.

1811 A. T. THOMSON Lond. Disp. II. (1818) 245 First artificially obtained in England in 1675, from the evaporation of the water of the Epsom spring: whence it was named Epsom salt.

1876 PAGE Adv. Text-bk. Geol. xv. 282 The manufacture of magnesia and Epsom salts.

2. Short for Epsom salt.
1803 A

an aside note
d. with a grain of salt [= mod.L. cum grano salis]: (to accept a statement) with a certain amount of reserve. Also in similar phrases, now esp. with a pinch of salt.
(b) Short for Epsom salts (see EPSOM). Also, like a dose of salts: see DOSE n. 2c.
1772
unusual meaning or connection:

1663 PEPYS Diary 29 Oct., Under every salt there was a bill of fare.
Salt;
Sexual desire or excitement (usually, of a bitch).
1519