Thoma-type haemacytometer
Date: 1885
Inventory Number: 1126d
Classification: Haemacytometer
Subject:
Maker: Carl Friedrich Zeiss (1816 - 1888)
Maker: Carl Zeiss, Optische Werkstätte, Jena (1846 - 1904)
Maker: Carl Zeiss (company timeline) (founded 1846)
Inventor: Ernst Abbe (1840 - 1905)
Owner: Harold C. Ernst (1856 - 1922)
Collector: Ernst-Lewis Collection of Microscopes
Cultural Region:
Place of Origin:
Jena,
City of Use:
Dimensions:
case: 2.3 × 17.8 × 7.8 cm (7/8 × 7 × 3 1/16 in.)
Accessories:
Description:
This haemacytometer (inv. 1126d) was an accessory ordered by Dr. Harold Ernst to be used with his Zeiss laboratory compound microscope with stand I (inv. 1126a).
Stored in the main flat case of the microscope, the haemocytometer (blood corpuscle counting apparatus) has its own leather-bound case. To open the box, one pulls a nail on the front corner of the box. The top of the case is stamped, "BLUTKÖRPERZAHLAPPARAT / NACH THOMA" and "C. ZEISS JENA."
The case contains a graduated glass pipette attached to a rubber tube, which is joined to an ivory mouth piece. The center of the case holds a cross-line micrometer which is on a glass slide marked, "0.100 mm. / 1/400 qmm." and "C. Zeiss / Jena." This indicates that the shallow cell (the counting chamber) on the slide is 0.1 mm deep and divided into 400 squares. A glass cover slip is included.
Stored in the main flat case of the microscope, the haemocytometer (blood corpuscle counting apparatus) has its own leather-bound case. To open the box, one pulls a nail on the front corner of the box. The top of the case is stamped, "BLUTKÖRPERZAHLAPPARAT / NACH THOMA" and "C. ZEISS JENA."
The case contains a graduated glass pipette attached to a rubber tube, which is joined to an ivory mouth piece. The center of the case holds a cross-line micrometer which is on a glass slide marked, "0.100 mm. / 1/400 qmm." and "C. Zeiss / Jena." This indicates that the shallow cell (the counting chamber) on the slide is 0.1 mm deep and divided into 400 squares. A glass cover slip is included.
Signedon case: C. ZEISS JENA
on slide: C. Zeiss / Jena
on slide: C. Zeiss / Jena
Inscribedon case: BLUTKÖRPERZAHLAPPARAT / NACH THOMA
FunctionThe haemacytometer is a device for counting blood corpuscles. The name is also applied to similar devices with counting chambers that are used for determining the number of cells per unit volume of a suspension.
Historical AttributesOwned by Harold C. Ernst, M.D., first bacteriologist in the United States. A letter (in the file) from Carl Zeiss to Harold Ernst in 1885 promises that this order from the factory would be expedited. Dr. Ernst worked at the time with Robert Koch and this was probably the reason for this extra attention.
Primary SourcesCarl Zeiss Optische Werkstätte, Microscopes and Microscopical Accessories (Jena, 1891), 75.
ProvenanceHarold C. Ernst; Department of Bacteriology; Harvard Medical School; Ernst-Lewis Collection of Microscopes (inv. no. 126), Harvard Medical School.
