But the Commissioner contends that the trading debt was discharged in September 1938 when the promissory note was given, and that the satisfaction of the promissory note therefore did not include any payment on account of any trading debt. The promissory note was for $1,000,000 and the debt owed was $1,067,201. No appropriation of this sum was made between the three separate debts in respect of which the note was given. It was given "on account" of the total liability. The company contends that the amount of $1,000,000 should be allocated ratably between these liabilities. The trading debt for goods supplied was $541,664. Therefore 541,664 1,067,201 of $1,000,000, i.e. $507,556, represented the part of the $1,000,000 which was attributable to the trading debt. Where one payment is made on account of a number of liabilities without any appropriation, it should be taken as reducing them ratably (see cases cited in Resch v. Federal Commissioner of Taxation [1] ). Thus $507,556 of the $1,000,000 should be appropriated to the trading debt. The expenditure incurred in paying off the $1,000,000 at the rate of exchange actually current when the payment was made was £312,668. 507,556 1,000,000 of that amount is £158,696. This sum represented the actual amount, part of the £312,668, which was provided in Australian money to meet the trading debt so far as the amount of that debt was included in the $1,000,000.