In the “Lancet” of November 15th last, Dr. Bucknill has propounded a new classification of insanity. The criticisms which he passed upon the etiological system of Morel in a former number of this journal (No. 38, p. 286), may be applied in the main, he thinks, to Skae's similar but more elaborate one. He had at one time intended to criticise the system of natural groups which has been proposed by Dr. Skae, but, on re-consideration, he determined to construct a system of his own, “which might more fully answer the purpose for which we needed it—namely, as a nosological scaffolding of form for the guidance of treatment.” We append Dr. Bucknill's preliminary remarks, and the scheme which he has constructed:—