Notwithstanding the differences in other respects in the present provision, the expression "incurred in gaining or producing the assessable income" has been left unchanged and bears the same meaning. In brief substance, to come within the initial part of the sub-section it is both sufficient and necessary that the occasion of the loss or outgoing should be found in whatever is productive of the assessable income or, if none be produced, would be expected to produce assessable income. It is by this standard that the question raised by the present cases must be determined. It is true that for the appellant companies it is claimed that if they fail by this standard there is an alternative standard by which they should succeed expressed in the reference contained in s. 51 (1) to losses and outgoings necessarily incurred in carrying on a business for the purpose of gaining or producing such income. The claim is that the course pursued by each company in the relevant accounting period in the conduct of its affairs amounted to the carrying on of a business, one entire business having for its purpose the gaining of assessable income. All the expenditure was incurred, so it was said, in carrying on the business: "necessarily" should receive a qualified meaning. If much that the companies did was attributable to a hope or expectation that eventually they would be able to resume mining operations in Malaya or Siam, that, it was contended, would not amount to a present purpose of gaining exempt income. There were too many contingencies under s. 23 (q), ranging from the future state of foreign tax laws to the satisfaction of the commissioner that future taxes would be paid. So many contingencies made it impossible to say that it was a purpose of gaining assessable income that would be exempt. With much of all this it is unnecessary to deal. Let it be assumed that neither company did more or less than carry on one single business when after the loss of its tin workings it pursued its way fulfilling the duties imposed by company law, concerning itself with the fate of its tin workings in South East Asia, holding itself in readiness to resume operations if and when fortune allowed, examining any prospective local venture that might be proposed and looking after the investment of its funds. Yet, excepting the income from investments, the subject of nearly all these activities was a concern of capital. When the companies were cut off from their undertakings in Siam and Malaya what they lost was the possession of capital assets. The re-establishment of the foreign mining businesses of which they had been deprived must be considered to be largely an affair of capital. So would the taking up of a fresh venture in Australia. Communications and business transacted with reference to the "Buffer Stock Scheme" may be put aside as a matter concerning exempt income. So far as anything else done by either company in the course of its inactive existence related to revenue, the only assessable income (as distinguished from capital) in view was interest upon investments. Accordingly, the reliance placed by the companies upon the second alternative in the positive part of s. 51 (1) will not advance their claim to deduct the full expenditure incurred in the respective accounting periods. It is therefore necessary to return to the opening words of s. 51 (1) and inquire to what extent the expenditure of the respective companies was incurred in gaining or producing the assessable income. The question is how far was it incurred in the course of, how far was it incidental and relevant to, gaining or producing the assessable income. Here again it is necessary to bear in mind that communications made and things done with reference to the buffer stock scheme relate to exempt income and that a consideration of a prospective new venture, like anything done with a view to the possibility of resuming the Siamese or Malayan operations, must largely be an affair of capital. Of course we are not here concerned with any very specific expenditure or any very definite operations. The whole matter relates to a few items the greatest of which are fees to directors and for management, but if their allowability is to depend on the nature of what was done, then principle requires that it should be borne in mind that the chief reasons for keeping up the structure of the companies on such a scale related to capital and not revenue.