Established in 1850, the German firm of Ernst Leitz (1843-1920) in Wetzlar became the leading manufacturer of microscopes by the end of the century. A company catalog published in 1896 claimed that they sold more microscopes in the United States than any other manufacturer. By 1900, Ernst Leitz had produced 50,000 instruments.

Moody Medical Library collection includes:

1.021

The oldest Leitz instrument in the collection is a small microscope, Stand V. The horseshoe base supports a circular pillar, to which the body-tube, square stage and mirror are attached. There is no substage. Focusing is by sliding the inner tube and adjusting the micrometer screw. About 1880. Signed: E. Leitz Wetzlar No 6017. [Not illustrated.]

1.061

This instrument has all the features of a late 19th-century Continental microscope. A short rectangular pillar sits on a horseshoe base and supports the limb and the stage on trunnions. The body-tube has a rackwork for coarse focusing and carries a triple nosepiece. Fine focusing is by the micrometer screw on the top of the limb. The substage, consisting of an Abbe condenser and iris diaphragm (which itself moves horizontally by rackwork), can be raised or lowered by means of rackwork. The double mirror is attached to the end of the substage mechanism. This microscope was purchased by Dr. William Keiller (1861-1931) in Edinburgh, Scotland, prior to his appointment in 1891 as the first Professor of Anatomy at the University of Texas Medical Branch at Galveston. It comes with wooden carrying case. About 1890. Signed: E. Leitz Wetzlar no 17327.

Additional Illustration: Case with instrument

Another Leitz microscope (1.066) similar to the above (1.061) with wooden carrying case, about 1896, and signed: E. Leitz Wetzlar & New York No 28744. [Not illustrated.]

1.077

This is a photomicrographic apparatus, mounted on a wooden work table by means of a cast iron base. An iron rail, attached to the base, supports the electrical lamp, the optical parts, and the bellows. The body-tube, which moves by rackwork, has a triple nosepiece. Below the mechanical stage, there is an Abbe condenser and an iris diaphragm. A brass plaque on the work table reads: "Photomicrographic Bench, c. 1900, by Ernst Leitz, Wetzlar. Used by Sir Almwroth Wright and Sir Alexander Fleming in St. Mary's Hospital, London. Presented by Dr. John Bunyan, Past President, Royal Microscopical Society, London, 1970." Signed: Ernst Leitz, Wetzlar. [Not illustrated.]

1.046

The horseshoe-shaped foot and the pillar are cast as one piece. The curved limb supports the square stage and the body-tube with a triple nosepiece. Coarse focusing is by rackwork and fine adjustment by micrometer screw. The substage, consisting of an Abbe condenser and iris diaphragm, moves vertically on rackwork. A rotating mirror is attached to the tailpiece. It comes with a wooden carrying case (covered with black buckram). The microscope belonged to Dr. Henry C. Hartman (1881-1963), Professor of Pathology and Dean at the University of Texas Medical Branch at Galveston. About 1925. Signed: Ernst Leitz Wetzlar No 238321.

There are two other Leitz microscopes (1.079 and 1.075) from the 1920s, with serial numbers 260657 and 290899, respectively. [Not illustrated.]

References:

Billings Microscope Collection, passim.
Leitz, Ernst. Microscopes and Accessory Apparatus. Wetzlar, 1896.