igS PHILOSOPHICAL TRANSACTIONS. [aNNO IT/l. 



drachm ; till the Greek physicians coming to Rome, and finding the 2 coins 

 nearly equal, prescribed by it, as they had been accustomed to do by the drachm 

 in their own country. Neither did the Roman pound depend on the weight of 

 the denarius, as the Greek, inina did on that of the drachm; but the weight of 

 the denarius depended on the pound. 



The ancient Roman pound was divided into 12 ounces, and the ounce into 

 24 scruples. And we learn from Celsus and Pliny, that 84 denarii were coined 

 out of the pound of silver; therefore, if we knew the true weight of the Roman 

 pound, we should thence know that of the denarius. There are many ancient 

 Roman weights now remaining, from under an ounce to 100 pounds; some of 

 them with inscriptions have the appearance of standards. Lucas Paetus, from an 

 ancient weight of 1 pounds, another of 4 pounds, and a third of 1 pound, in- 

 scribed EX. Avc. D. CAS. in letters of silver, besides three smaller of 3, 6, and Q 

 ounces, all six perfect and agreeing together, determined the ancient pound to 

 contain 11 ounces, 10 scruples, modem Roman weight. But where he gives 

 the weight of Vespasian's congius, he makes 10 ancient Roman pounds to weigh 



9 pounds 6 ounces 10 scr. 10 gr. modern weight. The modern Roman ounce 

 contains, like the ancient, 24 scruples, the scruple 24 grains. Therefore, ac- 

 cording to this determination, the ancient Roman pound should weigh 1 ] ounces, 



10 scr. 15A gr. modern weight, which is equal to 50124- Troy grains, if the 

 exact weight of the modern Roman ounce be 438 Troy grains, as Greaves 

 reckons it. But Paetus used a steelyard, which is a very fallacious instrument. 

 Many other weights are examined, from which are deduced a great variety of 

 weights for the ancient Roman pound, from 5000 up to 5780 grains Troy. 



The Roman congius contained 10 pounds weight of wine. Vespasian's stan- 

 dard is of brass; Paetus, Villalpandus, and Greaves, have given drawings of it; 

 and Gruter tells us, the inscription was in letters of silver. Several authors have 

 examined the capacity of this vessel, and the weight of the fluids it contains; the 

 medium of which gives 51591 Troy grains for the weight of its contained water, 

 the 10th part of which gives 5 159 Troy grains for the Roman pound. After 

 many other considerations on this point, Mr. R. adds: all the above circumstances 

 considered, it seems more probable that this standard should give too great a Ro- 

 man pound, than too small a one. But as nothing certain can be determined from 

 it, we must have recourse to the coins, especially the gold, which, though not so 

 correctly sized as the Greek Philippics, are much more so than the silver denarii. 



Pliny tells us, that when the Romans first coined gold, they made the scruple 

 pass for 20 sesterces. And from several good specimens, it appears that the 

 mean weight of the gold coin called the aureus, of 40 to the pound, was 126 

 Troy grains ; which gives 5040 such grains for the pound weight. 



The weight of this coin was gradually diminished by the emperors, till in Pliny's 

 time 45 were struck out of the pound. He died in the reign of Titus; and the mean 



