Hi Thread,
"Transactions for trading needed to be accounted for efficiently, so the clay tokens were placed in a clay ball (bulla), which helped with dishonesty and kept all the tokens together. In order to account for the tokens, the bulla would have to be crushed to reveal their content. This introduced the idea of impressing the token onto the wet bulla before it dried, to insure trust that the tokens hadn't been tampered with and for anyone to know what exactly was in the bulla without having to break it."
You could only use the bulla once because it had to be destroyed in order to get the tokens out! I think there are even examples of bulla with a kind of "signature" on them (an imprint with the seal of a noble family etc).
"send me a Bitcoin bulla" has a nice ring to it!
Sincerely,
LL