Degredation, identification and conservation of microscope slides

An experimental and curatorial study of entomological microscopy slides at the Natural History Museum of Denmark.

Microscope slides are an essential, but often overlooked, part of Natural History collections. This thesis investigates the degradation, identification and conservation of resin-based entomological microscope slides. This, using the collection at the Natural Historisk Museum of Denmark as a case study.

The study focuses on the mounting media: Canada balsam and Euparal, and examines their long-term stability, degradation processes and conservation challenges. Methods included: collection surveys, environmental monitoring, Raman spectroscopy for identification of unknown mounting media, accelerated aging experiments and practical restoration tests.

The results show that degradation varies depending on the mounting medium and storage conditions. Canada balsam was found to be more prone to yellowing, while Euparal generally showed greater optical stability. The study also demonstrates the potential of Raman spectroscopy as a tool for identifying historical mounding media and highlights the importance of preventive conservation and tailored restoration methods. 

Overall, the thises contributes to a better understanding of the preservation of historical microscope slide collections and the challenges associated with their long-term conservation.