VOL. LXI.] PHILOSOPHICAL TRANSACTIONS. IQQ 



aureus of Greaves's table from Nero to that prince, inclusive, is under 1 12 grs. That 

 of the Pembroke collection for the same period amounts to 1 13 ; but Nero's coins, 

 (contrary to Hardoiiin's reading of Pliny's text) appear to have been heavier than 

 those of Vespasian or Titus. By many s{)ecimens, it appears that the mean weight of 

 these reduced aurei was 1 12 Troy grs; which multiplied by 45, gives again 5040 

 Troy grs. for the pound weight. Alexander Severus coined pieces of one half and 

 one third of the aureus, called semisses and tremisses; whence the aureus came to be 

 called solidus, as being their integer. Soon after the reign of this prince, the coinage 

 became irregular, till Constantiue entirely new modelled it, by coining 72 solidi of 

 4 scniples, out of the jwund of gold, and for the denarius substituting the mili- 

 arensis. Greaves's 2d table exhibits 29 of these solidi, from Constantine to 

 Heraclius, weighing from 67^ grains to 70f . The mean from the 29 pieces is 

 6g grains, which, multiplied by 72, gives but 4968 grains for the weight of the 

 Roman pound. But if the standard weight of this coin amounted to 70 grains, 

 the pound will weigh 5040, agreeable to what it was found from the aurei. 



Having thus given as complete an account of the Roman gold, as he could 

 collect, Mr. R. next proceeds to examine the evidence we have of the weight of 

 their silver money. The consular silver is so unequal, that the Romans must 

 have been very negligent in sizing their pieces. Villalpandus says, that weighing 

 many denarii of the same form, inscription, and apparent magnitude, and so like 

 to each other, that they seem to have been struck, not only in the same age, but 

 even on the same day, he found them to differ in weight, 5, 9, or lO grs. from 

 each other. After noticing many instances of a difference in weight of this 

 coin, Mr. R. exhibits, in a table, the weights of 46 of the fairest denarii in the 

 British Museum, of all weights from 55 Troy grains, the lowest, up to 66^; these 

 being all added together, and the sum divided by the number of them, gives 

 60.95 grains for the medium weight. And he adds, but if we take 5040 Troy 

 grains for the weight of the Roman pound, as determined from the gold coins; 

 the scruple will weigh 174 grs; the consular aureus, 1 26; the imperial aureus, 

 112; and the solidus, 70 : all which are probable weights of the several coins: 

 and the consular denarius of 84 in the pound will weigh just 60 Troy grs. And 

 this must be very near its true standard weight; for were we to add only half a 

 grain to it, the consular aureus would exceed 127 grs., which is certainly too 

 great a weight for that coin. 



Though Pliny gives no particular account of any alteration in the weight of the 

 denarius, it was doubtless diminished by the emperors as well as the aureus, though 

 by what degrees is uncertain ; for Galen tells us, that the writers on weights and 

 measures differed in the number of drachms [denarii] they assigned to the oz. ; most 

 of them making it to contain 74-, some but 7, and others 8. The later writers make 

 it contain 8 denarii, of 3 scr. each. Greaves ' found, by examining many imperial 

 denarii, that from Augustus's time to Vespasian they continually decreased, till, from 



