Ethical considerations concerning the conservation and restoration of a herbarium from the 19th century

Magdalena Grenda The Warsaw Rising Museum, Poland Ethical considerations concerning the conservation and restoration of a herbarium from the 19th century Introduction Issues Herbaria are speciic objects: they consist of various organic materials joint together in a way that may cause unusual problems for a paper conservator. Plant material, supposedly complementary to paper as derived from plant material too, behave far diferently when subjected to conservation treatment. This poster illustrates issues concerning the conservation of a bound herbarium album. •The main goal of the conservation: reinforcement of the structure of the artifact. •The priority of the owner: bringing the item to the state enabling scientiic research; preparing for display. •First conclusions: ·all the loose material can no longer stay between the sheets of paper and it was necessary to ind a solution for over a half of specimens loosely laying on the pages. - all the processes (including matching of the plant material) should be completed during this particular treatment Fig.1. The herbarium before treatment. The herbarium was seriously damaged prior to conservation treatment. Broken covers, dismantled construction of the album and several damages in the paper support made the handling almost impossible. The artifact’s history and origin were little known, and the author of the herbarium was anonymous. The curator wanted to submit the item to historical botanist research but was afraid of making it accessible for anybody due to its very poor condition. Fig.2. Page 15 before treatment.The paper support was deformed, there were numerous losses caused by insects. The majority of plant specimens fell of the intended place and were dislocated, mostly cumulating in the area of spine. A lot of specimens were seriously damaged: broken, fragmented or crumbled. Fig.7. The herbarium after treatment. The block of the album was resewn, the binding and the woodblock printed paper were reconstructed. •Questions: ·what to do with loose material? (match? put in bufered envelope?) - who should match the plants? (conservator? What if he makes a mistake? Will the researcher then be able to safely remove the specimen from the sheet and attach it onto the right sheet without any damage to the specimen and the whole item?) • The solution: close cooperation between the conservator and a ethnobotanist. •Treatment design: the most subtle and reversible methods used in paper conservation to leave the plants possibly unafected. Fig.3. Plant fragments from page 5 prepared for matching. After slitting the sewing of the album, the loose plants and plant particles were taken out from the area of spine, the whole loose plants and possibly identiiable plant fragments were put into the envelope numbered after the number page they were found on. The matching process was consulted with ethnobotany professor Łukasz Łuczaj from University of Rzeszów and made it possible to match about 90% of specimens. Fig.4. Page 15 after treatment. Pages were dry cleaned. Brittleness of remained plant specimens excluded the possibility of extensive wet processes like washing, so only local wet treatment of the paper was considered when applicable. The brown stains were considered an identifying factor, helpful in matching some of the loose plants or identifying the lost material. The sheets were deacidiied from the back with Bookkeeper Spray which is supericial deacidifying agent and provides non-aqueous deacidiication. This was considered the safest solution both for the paper and plants as there are no clear guidelines for the deacidiication of plant material. The pH arouse from 5-6.30 before to 6.5-8 after conservation. Paper support needed strengthening which was provided by applying 2% methyl cellulose solution from the back of the sheet. After application the sheet was turned upside down and if there appeared the excess the methylcellulose on the plants, it was gently removed with damp cotton swab. Then the paper tears were mended and the paper losses were inilled. Fig.6. The fragments of the original woodblock printed paper. These fragments were found under the endbands and used as a source for reconstruction. The lexibility of plants changed dramatically due to the change of humidity and was expected get low again during drying under the pressure. The sheets were then pressed under soft layer of felt which gave good results for the most of the sheets. The ones for which this method didn’t work well were put in the press, between several layers of Whatman blotting paper sheets, after humidiication in Gore-Tex®. Conclusions •There is a need for further research on the inluence of conservation treatment methods to plant material. It would be desirable to examine the mutual inluence of diferent features of paper and plant materials and the efects of conservation on specimens. •The treatment conirmed the importance of a good photography documentation, especially if the conservator is consulting his work with other specialists and uses email as the fastest way to exchange the information. Good, extensive documentation also allows the evaluation of all stages of conservation treatment in the terms of later botanist research. In the described item some of specimens were wrongly assigned by the author of the herbarium and this may be proven only by the pictures made before conservation. Fig.5. Specimen mounting supported with dyed Japanese tissue. The plants were mounted using the original white paper strips and rice starch paste. If the paper strips were not suicient for that purpose, the attachement was supported with light Japanese tissue, dyed greenish colour matching the colour of the paper support. If the large leaves or petals were detaching from the sheet, they were pasted with a spot of rice starch paste onto the sheet. •The interdisciplinary character of conservation may give a great satisfaction if you ind a good specialist that you need to cooperate with. This kind of cooperation may also help to overcome technical problems which appeared in this case. •When coming across such item to treat, the relection is you cannot avoid intervention. This artifact proved to be in need for conservator’s extensive interference. Attempt to evade plant matching would result in making the artifact almost a useless sample instead of a historical source for botanists. Of course, it would make it less attractive for the exhibition purposes, too.