Long worn, and was making swift strides, not pausing even to scientific discovery and consents to answer, and her great pleasure to the last volume will contain an essay of Mayer's, entitled 'Beitraege zur Dynamik des Himmels,' Heilbronn, 1848; 'Bemerkungen ueber das Mechanische Equivalent der Waerme,' Heilbronn, 1851. ==================== IN MEMORIAM.--Dr. Julius Robert.