The clerk of the district court, upon being paid the fees allowed therefor by law, shall receive and deposit in his office, any last will or testament of a resident of the Virgin Islands which any person shall deliver to him for that purpose, and shall give a written receipt therefor to the person depositing the same. A subscribing witness to any last will or testament may make and sign an affidavit before any officer authorized to administer oaths setting forth such facts as he would be required to testify to in order to prove such will. Such affidavit may be written upon said will, or on some paper securely attached thereto, and may be filed for safe keeping with the last will or testament to which it relates. There may also be filed with such will, affidavits of qualified physicians licensed or permitted to practice in the Virgin Islands, certifying that the maker of said will was of sound mind at the time of its execution, together with any facts supporting such opinion.