However, some historians have shown scepticism towards the large number of sesterces quoted by Suetonius and Dio. According to Wilkinson, Caligula's use of precious metals to mint coins throughout his principate indicates that the treasury most likely never fell into bankruptcy. He does point out, however, that it is difficult to ascertain whether the purported 'squandered wealth' was from the treasury alone due to the blurring of "the division between the private wealth of the emperor and his income as head of state." Furthermore, Alston points out that Caligula's successor, Claudius, was able to donate 15,000 sesterces to each member of the praetorian guard in 41, suggesting the Roman treasury was solvent.