Specified-mode investment requirement: trust exemption requires substantial application of income and prescribed-mode investment of the remainder. Exemption for income from property held for charitable or religious purposes is conditional on applying the major part of income to such purposes during the year and investing any unapplied balance only in the forms or modes prescribed by law; both requirements are conjunctive. The prohibition on disallowed modes of investment does not apply to sums accumulated under the statutory accumulation provision, since that provision itself specifies the permissible mode of investment for such accumulations.