Final answer:
After being unable to exchange the money, Alex mortgaged his estates and resorted to trading in eunuchs, while in another narrative, Zerkow begrudgingly pays Maria for her junk after striking a bargain. The concept of money as a universal medium of exchange is also touched upon through the valuation of goods in units.
Step-by-step explanation:
After Alex is UNABLE to exchange the money, it is inferred from the information provided that he finds himself in a challenging financial situation. He mortgages all his estates to his brother, indicating a desperate measure to secure funds. Furthermore, he resorts to trading in eunuchs, which highlights the extreme lengths he goes to in order to generate income.
In a different scenario involving Maria and Zerkow, Zerkow carefully counts out the money for Maria's junk, showing his reluctance to part with his money even though a satisfactory bargain was struck. This illustrates a keen sense of value and the importance of money transactions in the character's lives.
Lastly, the reference to traders contemplating the value of meat and vegetables in terms of units points to the universal recognition of money as a medium of exchange facilitating trade without the need for a direct barter system.