S. 37(1) : Business expenditure-Foreign travel expenses-Directors’ visit to overseas subsidiaries for promotion of business-Commercial expediency-Allowable-Irrecoverable excise duty on sales returns-Expenditure incurred for business purposes-Allowable-Gift and gardening expenses-Expenditure incurred for business purposes-Allowable-Prior period expenses-Assessee unable to establish crystallisation of liability during relevant year-Disallowance upheld.