Iowa State University Library Special Collections recently acquired a beautiful collection of 94 botanical lantern slides made by Ada Hayden.  The slides — some of which are in color and some of which are black-and-white — had been found in an old cabinet sold by ISU Surplus.  The purchaser of the cabinet recognized the slides might be of some significance (a few said “Ada” and were dated “1918” on hand-written labels) and contacted the Ames Historical Society for confirmation.  Collections Curator Dennis Wendell confirmed that the slides had indeed belonged to Ada Hayden, and arranged for their donation to ISU Library Special Collections.

Surface grime on one of the glass lantern slides

Most of the slides were in excellent condition, other than some surface grime and oily fingerprint residue.  A few of the slides were cracked or chipped, but only one of them had broken into fragments.  Special Collections sent 65 of the slides to the Conservation Lab to be examined and cleaned before going to Digital Initiatives for digitization.  Be sure to check our Digital Collections in the coming weeks for images of the Ada Hayden lantern slides.

Cleaning the lantern slides with cotton swabs and deionized water

Cleaning a lantern slide with cotton swabs and deionized water

Over 400 cotton swabs were used to clean 64 lantern slides

In Conservation, the slides were examined, documented, and gently cleaned using cotton swabs and deionized water.  Deionized water is a surprisingly powerful polar solvent, and removed all of the residue on all but one particularly greasy slide, which required an additional cleaning with ethyl alcohol.  The cleaning process took an average of 5 to 6 minutes per slide.

To learn more about the composition, cleaning, and digitization of lantern slides, see the article written by Bill Yungclas and Melissa Tedone in the journal Microform & Digitization Review, “Digitizing Lantern Slides in the Warren H. Manning Collection.”