(see Dr. Wall’s “Prescription,” published at St. Louis, 1888). Apuleius, who wrote in the second century, gives
as a sign for an obolus which was equal to about 14 grains. That symbol could easily have drifted into our ℈. Hermann Schelenz (“Geschichte der Pharmacie,” 1904, page 153) makes up a table of medicinal weights and measures from Celsus, Pliny, and Galen, and quotes the following signs as being then used:
, sextans or obolus; ℈, gramma or scruple = about 20 grains;
, drachme or Holea = 3 scruples; γο, oungia or uncia = ounce; λι, libra = pound.
The drachm sign in Dr. Wall’s opinion is a reminiscence of an Egyptian symbol for half, somewhat similar to our figure 3,
. He supposes that the Greeks adopted this sign to represent the half of the Egyptian medicinal weight unit, which according to the best authorities was equivalent to a double drachm. In a treatise by Ebers on the Weights and Measures of the Ebers Papyrus, he estimates the weight unit at 6·064 grammes (say 103 grains). He explains, however, that the name of the weight is nowhere given in the Papyrus. I cannot say whether there is any evidence of the transfer of the Egyptian weights to Greek pharmacy, but the usual course of the travels of such characters was from the Egyptian hieratic or demotic writing to the Coptic, and thence to the Arabic. It appears certain, however, that the Arabic “dirhem” was adopted from the Greek “drachma.”