Some of the microscope slides I get are quite expensive, either rare examples, unusual mounts, or sought after makers. Others however are not. Today’s post is one with slides of the latter. I got two slides by Smith, Beck and Beck, and for the pair they cost me the princely sum of £5 (plus £3.50 postage). As it turned out, one of them was pretty much useless – degradation over time – but the other still had some good diatoms on it.
The images as per usual were done on my modified Olympus BHB, this time using 450nm oblique illumination. The 40x images used a Nikon UV-F NA 1.3 objective with glycerine immersion. Photoeyepiece was a Nikon 5x CF. Camera was a monochrome converted Nikon d800. Image resolution reduced to 1600 pixels across for sharing here.
Here is a stack of 10 images from the slide described as ‘Pleurosigma balticum’.
As well as there being plenty of P. balticum, there are various other diatoms on the slide including quite a few Surirella gemma. Quite a few of the examples have degraded somewhat, but there are still some usable ones on there. Most of the detail in the image above will be lost because of reducing the size for sharing, but the crop below is at original resolution.
As can be seen from the crop, there is plenty of detail in the P. balticum diatom.
A wide field of view using a 10x objective shows how more of the slide looked showing the variation and density of the slide.
Unfortunately the other slide, marked P. quadratum, was pretty much unusable (10x objective image below).
And of course, here are the slides themselves.
At first glance the slides look similar, but the printing and importantly the addresses are different. They were at 6 Coleman Street from 1847-1856, while at 31 Cornhill from 1865-1880 (according to Bracegirdle’s ‘Microscopical Mounts and Mounters’) which makes these some of the older slides that I have, especially the P. quadratum one. Last week I spent £5.40 at a service station for a sandwich while visiting the Archives of the Science Museum near Swindon to go through documents by Horace Dall (more on that soon after I have gone through my notes), so for less than my sandwich I got a nice slide to examine.
As always, thanks for reading, and if you’d like to know more about my work, i can be reached here.