Winkel-Zeiss WWII Military Field Hospital Microscope Kit

[This article first appeared in The Journal of the Microscope Historical Society Volume 16, 2008, and is reprinted here by kind permission of that journal’s Editor, Daniel Kile]

Introduction

The microscope kit described here was obtained via online auction from a dealer in the Slovak Republic. The dealer stated that he had obtained it from a Slovak household in which German soldiers, including a medical officer, were living during WWII; the microscope reportedly was left behind when the soldiers had to leave in a hurry. I was attracted to this microscope kit for two reasons: 1) during the Korean War, I had been assigned to the surgical unit of the 36th Evacuation Hospital, which was a “semi-mobile”, 400-bed field hospital, all under tents (it could be set up in 10 hours and taken down in 4 hours). Everything in this field hospital had to be portable—surgical suite, instrument kits, x-ray units, dental chair and drill, pharmacy, etc. Portable microscopes were part of the required equipment for the med-techs, as they had been during the two World Wars.
2) I had spent considerable time in the field engaged in aquatic microscopy, including a study of one lake over a ten year period. Portable microscopes, or “travelling” microscopes, are simply made to be more convenient to transport for field use. (Delly, 1968, 1995)

The vintage Winkel-Zeiss Göttingen microscope kit under review here, as illustrated in Figure 1, consists of the Winkel-Zeiss Diagnostic Microscope itself; a set of stains and reagents; microscope slides, coverglasses, slide labels and bibulous paper; a wooden box to store objectives and eyepieces; and a set of instruments; all fitted into a very sturdy wooden carrying case. Figure 2 illustrates how the components are arranged inside the carrying case. All together, case and contents weigh 25 pounds (11.34 kg).

The Microscope

The microscope supplied in this military field hospital kit was manufactured by Winkel-Zeiss, Göttingen, Germany; the serial number engraved on the microscope is 61999. The large white numbers at the top of the door of the carrying case match that of the microscope’s serial number. The microscope, illustrated in three views in Figures 3-5, is generally a horse-shoe-base monocular, fitted with nosepiece for three objectives; fixed-length non-drawtube body; coarse and graduated fine focus in high position acting on the body tube; centerable, rotating, non-graduated stage; tiltable limb/base; double-sided plane/concave mirror; and 1.2 NA substage condenser, with swing-out filter carrier, and long, low, vertically-disposed, focus adjustment, terminated by a knurled knob.

There are three non-coated achromatic objectives:

10X Ap. 0.28 Winkel-Zeiss Göttingen #93912

42X Ap. 0.85 0.17 Winkel-Zeiss Göttingen #94318

90X Ap. 1.30 H. I. Winkel-Zeiss Göttingen #94504

The objectives come stored in black plastic cases, housed in a fitted wooden container (Figure 6). Only one eyepiece came with the microscope, a Winkel-Zeiss Göttingen 6X, but typically at least one additional eyepiece would have been supplied, most likely a 9X compensating eyepiece, and I have subsequently added this eyepiece and a 5X to fill out the kit.

The microscope did need some restoration attention, particularly the stage. The stage, interestingly enough, is made of aluminum—I am assuming that the components of brass were needed for munitions. The black finish was mostly missing, and the stage was badly pitted. In addition, the stage would not rotate, and the centering screws were adjusted in such a way as to lock the stage at one extreme. The stage required disassembly, refinishing, relubrication, and reassembly. Of course the coarse and fine focus mechanisms needed to have the old, polymerized lubricant removed and replaced. Some chips in the paint needed to be touched up, and all of the optics thoroughly cleaned. The microscope is now fully functional.

Dating the Microscope

I do not have any Winkel-Zeiss catalogs or reference material; however, I did find some information in a 1934 edition of a Zeiss, Jena catalog (Carl Zeiss Jena, 1934). The Cyril Kett Optometry Museum and Archive website states that “Rudolph Winkel was a contemporary of Carl Zeiss in the field of microscopes but gradually the family participation in the business declined and it was sold to Carl Zeiss who kept it as a totally separate business until 1954 when it became the microscope division of Carl Zeiss (Oberkochen). The firm was located in Göttingen”. The name is seen as Winkel, Rudolph Winkel, Winkel-Zeiss, or Zeiss-Winkel. In the catalog Zeiss Microscopes and Accessories Mikro 1 USA, 1934 Edition, there is a section at the very end called, XIX Microscopes by R. Winkel G. m.b.H., Göttingen. Figure 7 is a copy of p.147 from this section, and illustrates, at the far right, what I take to be the immediate precursor of the microscope under review. Specifically, the stand GTB most closely resembles the one in this kit, although the pillar, limb, location of focus controls, and substage condenser adjustment are of different appearance; clearly there were design changes during the decade following issuance of this catalog.

Unfortunately, the dated reference card that would normally be present on the inside of the carrying case door was missing—only the holes from the four small attaching brads remain. By coincidence, however, in July 2008 a Winkel-Zeiss microscope of the same design, but not military version, was offered on eBay. Its serial number was #68837, and the reference card is dated 15 October 1943. Thus, my microscope is 6,838 serial numbers earlier than October 1943—but the numbers do not necessarily apply to the same model; probably not (by the way, this eBay microscope, which was supplied with Carl Zeiss Jena objectives 81/0.20, 40/0.65, 90/1.25, and 6X and 9XK eyepieces, sold for $255.99 after 24 bids).

Stains and Reagents

The stains and reagents, seen at bottom left in Figure 1, are housed in a wooden box with a red-painted sliding lid. The center section of the box holds over two gross microscope slides, five boxes of coverglasses (50 each, 18 mm diameter; microscopische Deckgläser, Resistance, Gar. Haltbar), a box of three pads (4 cm x 6.5 cm) of blotter-like paper, and a glassine envelope of slide labels.

Around the inside walls of the box are twelve black-plastic, screw-type containers that hold the bottles of stains and reagents. The bottles are glass-stoppered and glass-capped. Two of the bottles and their containers are empty and unlabeled; ten of the bottles and their containers are labeled, but, with one exception, the contents were dried out or had deteriorated over the last 60-70 years. I managed to successfully remove both the glass caps and the glass stoppers, so I was able to clean the containers, and refill them with freshly-prepared contents. Nine of the ten labeled bottles and their containers are illustrated in Figure 8.

A list of the stains and reagents included in the kit follows:

1. Karbolfuchsin [Carbol fuchsin]
2. Giemsalösung [Giemsa solution]
3. Karbol Gentianaviolett [Carbol gentian violet]
4. Löffler’s Methylenblau [Löffler’s methylene blue]
5. Jodjodkalium [Iodine in aqueous potassium iodide]
6. Alkohol-Salzsäure [Alcohol-Hydrochloric acid]
7. Paraffin liqud [Liquid Paraffin; White mineral oil]
8. Zedernholzöl [Cedarwood oil]
9. Xylol [Xylene]
10. Alkohol [Ethanol]
11. (Blank) Empty
12. (Blank) Empty

What can we make of this selection?

Carbol fuchsin (Ziehl’s stain; Ziehl-Neelsen), fuchsin in alcohol and aqueous phenol is used in the general study of microorganisms, and specifically, for determining leprosy and tuberculosis (leprosy and tubercle bacilli, red; other bacteria, blue).

Giemsa solution. Giemsa’s solution is used to stain blood smears, and for smear preparations of unicellular organisms.

Carbol gentian violet. Its commonest use is in Gram’s stain for the demonstration and primary classification of bacteria. It can also be used for fibrin network in blood smears (fibrin stains violet; white cells appear as irregularly-shaped black dots; platelets appear as black dots).

Löffler’s methylene blue. Methylene blue is a commonly used dye. Due to its strong metachromatic staining properties, it can be used for the demonstration of mucins, cartilage, mast cells, etc. In hematological methods, it is used for the visualization of blood parasites and/or protozoans; the nuclei of blood parasites/protozoans appear red. The typical color of cell nuclei is purple. It is also used in conjunction with the carbol fuchsin to carry out the classic Ziehl-Neelsen staining for mycobacteria, which are normally difficult to stain because of the high proportion of lipid and wax in their cell walls. Once stained, acid-fast mycobacteria remain red after counterstaining with methylene blue, even after treatment with strong decolorizing solutions, such as acid-alcohol.

Iodine in aqueous potassium iodide. This is for making up Gram’s stain for differentiation and characterization of bacteria—even for bacteria in sections (Gram positive organisms are stained violet; Gram negative organisms are stained red; nuclei are stained pink; cytoplasm is stained yellow.

Acid Alcohol. This mixture of, typically, 3 ml HCL and 97 ml 95% ethanol is used for decolorizing in staining procedures.

Paraffin liquid. (White mineral oil; liquid petrolatum) a general protectant and lubricant.

Cedarwood oil. The immersion liquid for the 90/1.30 H. I. objective; the original immersion oil; the refractive index (D, 20°C) = 1.5020-1.5070.

Xylol (xylene) solvent for cleanup after using cedarwood oil.

Alcohol (ethanol). General reagent for cleaning and disinfecting.

In conclusion then, these stains and reagents have been selected for a wide range of hematological and bacteriological methods, including tuberculosis.

Instrument Set

The instrument set is illustrated in Figure 9. It consists of a gray-painted metal box with removable tray and sliding-wire lock. In the figure, the removable top tray has been moved to the open cover (left), and the instrument retaining clamps have been opened. The tray instruments, consist of a two-part (wood bottom; aluminum top) screw-together innoculating needle hallmarked with a crown surmounting a caduceus, (far left in the photo); an 8 cm length of platinum or nichrome wire for the innoculating needle; a two-part metal tube containing three 5 cm long straight dissecting needles; a 13 cm long dissecting needle holder, with thumb screw clamps, also hallmarked with a crown surmounting a caduceus; a 14 cm long section lifter, hallmarked with crown surmounting caduceus; and two 9 cm long brushes with plastic handles. In the base compartment under the tray there is a capped metal alcohol lamp (center); two pairs of squeeze-to-open forceps; and a nested set of glass dishes—one of which was broken in shipment. I do not know what other instruments might have been originally supplied. Certainly the inoculating needle and alcohol lamp complement the stains supplied for culturing and identifying bacteria.

In the carrying case there was also a box of 6 cm x 13 cm tablets of bibulous filter paper (Medicihaus Aktiengesellschaft, Karlstr.31, Berlin).

The Carrying Case

The sturdy wooden case is 8 ¼” wide, 9 3/8” deep, and 18 ¼” high (~ 21 cm x 24 cm x 47 cm ); it is reinforced with eight metal corners. In addition to a rather beefy key lock on the left-front side, there are two metal finger-lever locks—seen in open position in Figure 1. The carrying case is painted olive-drab, with a red-and-white Red Cross symbol on all four sides, and the microscope serial number, 61999, painted in white. The olive-drab paint and Red Cross symbols were later additions, as by glancing light there is evidence of earlier printing on the front door, which can just be made out. The order of the text, together with translation to the right is:

Mikroskopier   Microscope
Ausrüstung     Equipment/Outfit/Kit
Stat.              Stand (Stativ)
aufrecht         Upright/erect
stellen            Standing

At the top of the case is a metal carrying handle mounted in a recessed area of the wood. Four rubber feet on the bottom of the carrying case had totally disintegrated, and needed to be replaced.

It was a great pleasure to curate and restore this Winkel-Zeiss WWII Military Field Hospital Microscope Kit, and it is now ready for another 70 years of service.

References

1. Delly, John Gustav (1968). Portable and Pocket Microscopes. The Particle Analyst 1 (16) 137-143 (August 20, 1968).
2. Delly, John Gustav (1995). Aquatic Microscopy Fieldkit. “Diffraction Lines” column in The Microscope 43 (2) 91-98.
3. Carl Zeiss Jena (1934). Zeiss Microscopes and Accessories, Mikro l USA, 1934 Edition, Jena, Germany