In the Mineral and Metallurgy Department of the Exposition, the Argentine Republic has an effective display of a general collection of minerals and three special exhibits of petroleum and combustibles, borates, salts and materials for construction. In regard to these, more attention has been given to the object of securing typical samples which demonstrate the character of the various ore deposits, than to the consideration of the actual number of samples. In the collection of petroleum and combustibles, there are samples from the following deposits: Commodore Rivadavia, Laguna de la Brea, Cerro Buitres, San Rafael, Cacheta, Covunco (Neuquen), Cerro Sotena, Challaco, Mina Carmelo (Salta), Yacuiba, Garrapatal (Jujuy). This collection contains 39 different samples, with specific details and statistics especially tabulated in every case. The exhibition of marbles and stones for purposes of construction is most complete. Here are to be seen the famous marble onyx of San Luis and of San Rafael, the marbles from the Sierras of Cordoba (represented by 15 varieties), and specimens of the large granites of Sierras Bajas, Olavarria, etc. There is also a collection of mineral waters in which are included those mostly used in the thermal establishments of Rosario de la Frontera; whilst, as a decorative contribution to the exhibition there is a plastic representation of the Sierras of Famatina, showing a part of its wonderful aerial railway, together with an admirable series of photographs, maps, and diagrams embracing practically every branch of the mineral and metallurgical industries.