Among the assets outside the house, Demosthenes first mentions his father's maritime loans (always interest-bearing), managed by Xuthos,(128) and he ends with a sum of around one talent loaned free of interest, in tranches of 200 and 300 dr.
Such an investment would have the additional advantage of a secure return, unlike the more risky maritime loans.
We may also speculate not unreasonably that any profits from the large maritime loans which we know the son of Sopaeus made (Isoc.
9-11) allows us to make a few inferences, most notably that much of Demosthenes' wealth was likely to have come from interest on loans, including profitable maritime loans.
And the lack of conclusive evidence that banks made maritime loans might seem to suggest that they had a restricted role in financing maritime trade.
Whether or not banks made maritime loans as such, they clearly could play an important role in enabling these loans to be made and in supporting maritime trade.
Diodotus' estate included a number of very large loans: 46,000 dr in maritime loans, 10,000 dr in landside loans, together with a large deposit of 30,000 dr with Diogeiton.
Apart from 3,000 dr of bank deposits Demosthenes has 7,000 dr in maritime loans, 6,000 dr in loans at 12 per cent, loans of 6,000 dr in small sums and 1,600 dr which may also have been loaned at interest.
Other property, whatever it may be, can best be shown to exist by reference to those who actually possess it, whether as bankers (like Pasion) or as managers of maritime loans (like Xuthos).
But not all his arguments to prove that banks did make maritime loans are equally convincing.