Summary in spanish:
Apéndice sobre la vida y obra de Juan Mateo de Zabala que se añade a una obra anterior. La información proviene de documentos que el autor posee como testamentos, cartas, etc.
Summary in english:
Appendix on the life and work of Juan Mateo de Zabala that is an addition to a previous work. The information comes from documents that the author possesses, such as testaments, letters, etc.