Note 47 — PETER KALM’s TRAVELS. (continued 5)
Johann Reinhold Forster translation
It seems to be either the substance commonly called French Chalk, or perhaps the Soap-rock, which is common in Cornwall near the Lizard point, and which consists besides of some particles of talc, chiefly of an earth like magnesia, which latter with acid of vitriol, yields an earthy vitriolic, salt, or Epsom salt. F. ↑