A pair of beautifully decorated and colourful late 18th early 19th C Italian majolica apothecary jars labelled “En Veneris” and “Aethiopis Mineralis”,

The “En Veneris” jar has a crest showing the arms of the Piemontese family of Pejla, counts of Avuglione [Heraldic site]. The “Aethiopis Mineralis” jar shows the arms of the Two-Sicilies noble house of Gaeta, counts of Sant’Angelo Limosano [Heraldic Site].

Aethiopis Mineralis is the black sulphide of mercury, obtained by titrating mercury with sulphur. ‘Aethiopic’ usually meaning ‘black’. Mercury was considered by alchemists to be the ‘First Matter’ from which all metals could be formed. It is name of the Roman messenger of the gods who is linked with the medical profession in the sign of Caduceus. Known to be toxic since the 1600s it has variably been prescribed for constipation, depression, child-bearing and toothaches. With thanks and credit for research to Stephen Plowman and Adam Mclean.

“En Veneris” which is Ens of Venus, a chemical prepared from a mixture of Colcothar (the brownish-red ferric oxide left over after heating Green Vitriol, that is Iron Sulphate) and Sal Ammoniac (Ammonium Chloride) sublimed until it became yellow. Possibly a mixture of ferrous and ferric chlorides.

With thanks and credit for research to Stephen Plowman and Joseph McMillan (heraldry) and to Adam Mclean (alchemy).

• From the Phisick collection