Palmer Slide Company

They (Palmer Bevel-Edge Slides) create great beauty of the finished object, making them the most elegant slide yet introduced, and their beveled edge allows them to easily glide under the spring clips on the stage of a microscope.

G. S. Woolman

In 1886 the Palmer Slide Company began the commercial manufacture of standard-sized microscope slides. Purportedly, Palmer was first in the U.S. to do so. The company conducted their sales and correspondence from offices in Geneva, NY. The factory manufacturing its products was in Cleveland, Ohio.  Palmer made microscope slides, coverslips, mounting media, slide cabinets, and other laboratory supplies. To round off its inventory, it also imported microscopy items from England.  In an editorial column written in the St. Louis Medical and Surgical Journal, Frank L. James announced that The manufacture of ground edged slips for mounting microscopic preparations was but a few years ago entirely in the hands of foreigners — English, French, and German being the only ones to be procured.

        In addition to manufacturing standard-sized microscope slides, the Palmer Slide Company introduced an upscale glass microscope slide of their design. They made the new slides from glass a millimeter thicker than that used for standard slides while keeping all other dimensions equal. The additional thickness enabled an angled edge to be ground along the top of the slide’s four sides. The slides cost more than standard ones, but their target market was microscopists wanting to give their prepared mounts a quality look. The company advertised the slides in several microscopy publications for prices between $4.00 and $6.00 a gross or about three to four cents a slide – which was not cheap in 1886. They were called the Palmer Bevel-Edge slide and made them available with the slide’s angled edge being polished or frosted.

Beveling the sides of a glass slide will create a razor-sharp edge making the slide difficult to handle to avoid cutting oneself.  Also, a thin edge would easily chip, increasing the likelihood of damaging the slide. The Palmer Slide Company’s design stopped angling the slide 2 mm above the bottom edge. Doing so left a nine-tenths millimeter perpendicular edge around the base. In this way, the bevel ground around the slide’s periphery did not intersect its bottom. Even though Palmer Bevel-Edge slides can be handled without fear of cutting oneself, they are still more susceptible to edge chipping than standard slides.

      Palmer Slide Company sent examination slides to editors of various microscopy journals hoping to get positive reviews of the slides published in the journals – a marketing technique still in common practice. Romyn Hitchcock, the editor of American Monthly Microscopical Journal (A.M.M.J.), received a promotional set of the Bevel-Edge slides from the Palmer Slide Company. In his monthly column titled “Notes,” Hitchcock reported to his readership that These slides are certainly very attractive in appearance and are well adapted for ornamental preparations.

      He further noted that the glass Palmer used remained remarkably color free, even when the slides were viewed edge-on. Hitchcock stated that Palmer made the beveled edged slides from Chance’s crystal plate or Chance’s flat crown glass stock imported from England. Hitchcock also commented on several bevel-edged slides submitted for review that had their undersurface flashed with color, and that this would make them especially attractive when used for making opaque mounts

      Colored Palmer Bevel-Edge slides have yet to find their way into this collection, so it is not confirmable as to what Hitchcock meant by “flash” coloring. It is assumed to be the same process of painting glass as used for coloring the outside of the period’s inexpensive cranberry glassware. This is an inexpensive coating of the glass that can be rubbed off by frequently repositioning the slide on a microscope stage. A true flashing process requires dipping a clear glass slide into molten colored glass. Doing so provides the slide with a colored glass covering over the clear glass slide. Grinding a bevel along the top edges of a slide flash colored with this method would cut through the color to the clear glass beneath. Using such a quality flashing method would make exhibition microscope slides that would be glorious to behold. Be still my beating heart.