Section 19. An appellant from decrees of a probate court settling different accounts of an executor, administrator, guardian, conservator, trustee or receiver may unite his appeals in one notice of appeal, and they shall thereupon be entered as one appeal in the supreme judicial court; and an appeal taken by another appellant from any of the same decrees, or from another decree made at the same time or earlier, settling any other account of such fiduciary, may be entered in the supreme judicial court as part of the matter comprised in the appeal previously entered. The court may, upon appeal, deal with such different accounts as if they formed one continuous account, and may give effect to any alterations which it may make in any account by altering the balance of the last account without altering the balance of any previous account.