The proponent may prove the content of a written statement of the party against whom the evidence is offered without producing or accounting for the original.
Mass. Guid. Evid. 1007
This section is taken from Smith v. Palmer, 60 Mass. 513, 521 (1850). See also Cooley v. Collins, 186 Mass. 507, 509-510 (1904); Clarke v. Warwick Cycle Mfg. Co., 174 Mass. 434, 435 (1899).