Legacies are distinguished and designated, according to their nature, as follows:
1. A legacy of a particular thing, specified and distinguished from all others of the same kind belonging to the testator is specific; if such legacy fails, resort cannot be had to the other property of the testator.
2. A legacy is demonstrative when the particular fund or personal property is pointed out from which it is to be taken or paid; if such fund or property fails in whole or in part, resort may be had to the general assets as in case of a general legacy.
3. An annuity is a bequest of certain specified sums periodically; if the fund or property out of which they are payable fails, resort may be had to the general assets, as in case of a general legacy.
4. A residuary legacy embraces only that which remains after all the bequests of the will are discharged.
5. All other legacies are general legacies.