Two serial issues of Comptes Rendus Hebdomadaires des Sǎnces de l'Acadm̌ie des Sciences. The collection has only the paper by Mendeleeff on discovery of gallium in the volume 81, issue 21, pp. 969-972. The first issue in the collection, Compte Rendu, 81 (1875), No.15, was supposed to contain the paper of Paul- mile Lecoq de Boisbaudran on discovery of gallium,"Caractr̈es chimiques et spectroscopiques d'un nouveau mťal, le gallium, dčouvert dans une blende de la mine de Pierrefitte, vallě d'Argels̈ (Pyrňě)". However, the pages 493-495 with this paper are missing from the bound collection.