The aim of this paper is to analyze the "Prologue" of the Universal Popular Dictionary of the Spanish Language, (Barcelona, 1885-1889), compiled and directed by Luis P. de Ramon. It is an exceptional example among those of the time due to its length -25 pages-, its sources -it is a direct debtor, among others, of the "Preface" of the GDU by Pierre Larousse-, but, above all, due to its metalexicographic singularity being the first to make a critical review of Spanish and foreign lexicography. A detailed study of sources, intertextuality, influences and purposes is carried out in order to provide new data for the study of the non-academic lexicography of the 19th Century.