Evidence of terms of contracts, grants and other dispositions of property reduced to form of document

When the terms of a contract, or of a grant, or of any other disposition of property, have been reduced to the form of a document, and in all cases in which any matter is required by law to be reduced to the form of a document, no evidence shall be given in proof of the terms of such contract, grant or other disposition of property, or of such matter, except the document itself, or secondary evidence of its contents in cases in which secondary evidence is admissible under the provisions hereinbefore contained. Exception 1.—When a public officer is required by law to be appointed in writing, and when it is shown that any particular person has acted as such officer, the writing by which he is appointed need not be proved.