In this paper, we describe and analyze the introduction and the use of the nuclear emulsion technique in Brazil. Even though consistent researches in cosmic ray physics had been done since the forties of the last century in this country, physicists here only began using this technique after Cesar Lattes' works in Bristol (England) and Berkeley (US). Despite being the implantation of the technique in this country posterior to the origin of the method itself - dated from late 1900s -, Brazilian scientists were quickly familiarized with it and adopted it not only in cosmic rays, but also in particle physics and nuclear physics, employing it until recently. In our work, we will be concerned with the reasons of this longevity. In other words, why were the nuclear emulsions technique employed for so many years in Brazil, even after its vanishing in physics researches centers in the world? We advance here that the answer to this question involves the institutionalization of science in Brazil - mainly physics - and economical, social, and geographic reasons.
history of physics; history of physics in Brazil; technique of nuclear emulsions; photographic method applied to physics
