of 1 drachm of the following mixture of powders to each 1/2 oz. of plaster:—Crocus of antimony, vitriol of calcined rubies, and red precipitate; equal parts worked in with a little oil of turpentine. Other forms were given by different authors, but this was the one which was adopted in the P.L., 1721.
Just when the name was transferred from a plaster to the liquid soap liniment cannot be traced; it was applied to an ointment on the way. There is a formula for an Unguentum Opodeldoch in the first Edinburgh Pharmacopœia, 1722, as follows:—
"Rad. angelicæ, aristolochiæ longæ, imperatoriæ,
aa 2 oz.;
"Fol. ocimi (basil), origani, salviæ, serpylli,
"Flor anthos, lavandulæ, aa 1-1/2 oz.;
"Bacc. juniper, lauri, sem. cummini, aa 2 oz.; castorei, 1 oz.
"Affunde Spirit. Vini Rect. congium unum. Digere
frigide per triduum in vaso clauso; tandem humitatur
in B.M. tepidum per horas aliquot. Colatura expressæ
adde
"Camphoræ 1 oz., saponis Venet. minutim incisi,
lbii.
"Digere rursus in vase circularorio juncturis lutatis,
leni calore B.M. donec coeant in unguentum."
Steer's opodeldoc was similar to this compound, but with some ammonia added. It appeared about the middle of the eighteenth century, and foreign dispensatories state that it was the patent of an English doctor. I have not been able to trace either the patent or the doctor. Steer's opodeldoc was evidently the model imitated in most of the foreign pharmacopœias.
