Member of the Microscopical Society of London,was born at Lancaster July 23rd, 1782,anddied at Lancaster June 21st, 1866. His father, a surgeon in practice at Lancaster, contributed several communications on medical and surgical subjects to the London medical journals near the close of the last century. When a young man, Mr. Johnson devoted himself laboriously to the study of chemical and electrical science. He graduated, at Edinburgh, after a three years’ course of medical instruction at the Boyal Infirmary. He then commenced practice in Settle, in Yorkshire, where lie remained till 1808, when he returned to Lancaster. In 1813 he published a translation of an essay on ‘Child Murder,’ by Dr. P. A. 0. Mahn, of Paris. In 1817 he translated the whole of 1 Orlando Furioso ‘into prose. In 1832 he contributed in the local press a series of sanitary papers with reference to the impending cholera. He contributed a manual called ‘The Nurse’ to a series edited by Martin Doyle, 184.2. In 1841 he published several articles on agricultural chemistry in the local papers. About ten years later, he published others under the signature of “A Fireside Farmer,” in which he explained the views of Dumas and Boussingault, and other physiological chemists. In 1848 he commenced the study of diatoms, which he followed with unwearied diligence till within a brief period of his death. In 1849 he translated Menighini’s work on the animal nature of the Diatomaceæ, which was published by the Ray Society. In 1865 he published some papers on the disinfecting properties of carbolic acid, the last of which was printed in the ‘Lancaster Gazette ‘in November, 1865. He was one of those quiet workers with the microscope who did much for diffusing a taste for the investigation of minute organisms by his continuous work at the forms of Diatomaceæ.