In 1891 Baron Maurice de Hirsch founded the Jewish Colonization Association (J.C.A.), which was to become one of the largest philanthropic firms of their time, conducting a gigantic experiment in social welfare consisting in the organized immigration of thousands of people from the Russian Empire to Argentina and setting up agricultural colonies. Colonia Mauricio, close to Carlos Casares, in the Provincia of Buenos Aires, was established in 1891 on the first land acquired by the J.C.A. in Argentina and by far the most fertile. In the early 20th century, the prosperity of the colony reflected the ideal of Hirsch, who in 1892 had stated in an interview with the New York Wor1d: “These exiles are so poor that if they are given the means to work and they are taught to work the land, so that the harvest would be sufficient to feed their families and earn some profit as well, I have no doubt that they will make good use of the opportunity.” However, Colonia Mauricio rapidly disintegrated. For 1930 the colony was only a memory. What happened? In this paper we will reconstruct the history of Colonia Mauricio from two complementary primary sources: the memories of Boris Garfunkel, one of the first and more important settlers, and the historical review written by Demetrio Aranovich, the first Russian Jew who earned a Doctorate degree in Medicine in Argentina, who attended the health needs of the colony in the early 20th. We will evaluate the hypothesis proposed by Aranovich as responsible for the dissolution of the Colony, and we will collate it with the vision of Garfunkel on this event.