Portable microscope for blood analysis by a veterinarian
in the field
Late 1920 to early 1930 vintage
The set consists of an elementary folding microscope where the body
and tube (which has a draw-tube) are stored separately within the case. While
the microscope itself is unsigned by the maker, the objective lens is marked
Bausch & Lomb Opt. Co. 16mm, 10x. The brass objective appears to be late 1920 -
early 1930 vintage. The eyepiece is marked 5 and has a reticle consisting of
a grid of squares. Additionally, the set has a vacuum chamber that has mountings
within its center to hold a microscope slide. A large syringe is provided which is used to
create a vacuum. Within the case is a wood box with blank microscope slides,
a metal container for cover glasses, and one for soft porous rings. The purpose of the vacuum
and the use of a porous ring and cover glass would be to create a thin layer of blood within
the ring mounted on the slide. There are three vents to release of the vacuum. The caps
on these vents are linked together with a chain allowing them to be removed
simultaneously thus allowing air intake uniformly along the length of the slide.
There is a cardboard
box with bleeding needles. The gauge of the needles is large indicating
they were most likely used for getting blood from large animals. Given the portability
of the set, it seems likely it was used in the field by a visiting veterinarian for blood analysis.