Among the many topics of interest for the history of twentieth-century science are the transmission of science from productive scientific centers to the periphery and the history of low-temperature physics. It happens that both topics met in the case of the Spanish physicist Julio Palacios, who worked at Kamerlingh Onnes' laboratory in Leiden from October 1916 until the end of the First World War. In this chapter, it is discussed how he came to apply the expertise he had acquired there when he returned to Spain. As a matter of fact, he was unable to introduce in Madrid what he learned in Holland because of the technical sophistication and exigencies of research in low temperatures, turning instead to X-ray diffraction, a promising field less technically demanding (his work and international connections there are also covered). In view of that story, it is concluded that an appropriate scientific policy for underdeveloped countries is not necessarily to send their young and most able scientists to the best research centers in the world. In the end, it was Onnes' laboratory that benefited more from Palacios's stay, because, without any expense on its part, it obtained the help of an able young physicist, at a time in which Leiden did not receive many visitors.