Interest. That's why they have "chequing" and "savings" accounts. GAIN is money you did not labour for.
Money of EXCHANGE is taxed as INCOME
Money of ACCOUNT is taxed as EARNINGS
Printed copy · Anthology Volume 4, page 236Printed copy from The Tender For Law Anthology, Volume 4, page 236 (printed 13 June 2014). Added by this site; not part of the Facebook export.