[Nitrous oxide in dental anesthesia: facts about its introduction in Spain]. / El óxido nitroso en la anestesia odontológica: datos sobre su introducción en España.

After a free period of twenty years the interest for using nitrous oxide in suppressing pain related to dental surgery has increased since the end of the sixties of the last century. In this work we present the result of our investigations on the person who must be considered the introducer of this technique in Spain: José Meifrén Alfares, odontologist at Barcelona.

[Antionio Morales Perez and thermal etherization]. / Antonio Morales Pérez y la termoeterización.

During the last decades of XIXth century, after a 40-year parenthesis, interest on ether as anesthetic agent is being elicited again in some European countries. In the present paper, we study the personal method of Antonio Morales, the Spanish surgeon. His method, the so-called thermic etherization, is encompassed within the group of techniques that were based on anesthetic vapor heating techniques. We also describe the device designed by Morales and the changes that were introduced later on.