The article "Puerto Ricans Debate Statehood," Aug. 15, is a sad commentary on the self-serving interests behind the debate over statehood. Puerto Ricans' chief concern seems to be what they would gain or lose economically or whether or not they would pay federal income taxes and what welfare and trans-fer payments they would get. Yet the Puerto Ricans are not willing to become part of the great melting pot which blends together many nationalities.These nationalities have, for the most part, subordinated their language of origin to English, but Puerto Rico's new "Spanish only" law shows the desire to stay separate and apart. "Spanish only" is a bad omen; it would mean confusion not only for the Puerto Ricans themselves, but also in their relations with the federal and state governments and in business transactions and industrial dealings. Charles F. Rasoli, Long Island City, N.Y. Letters are welcome. Only a selection can be published, subject to condensation, and none acknowledged. Please address them to "Readers Write," One Norway St., Boston, MA 02115.