Discover more about the conservation work carried out on one of the most important, popular and fascinating collection in the Archives.
Amongst the several million original items in Kew’s Archives is a series of 44 letters between Charles Darwin and his mentor, Professor John Henslow, which document Darwin’s travels on HMS Beagle. Written between 1831 and 1837 these fascinating letters show Darwin’s theories developing as he collected specimens and reported his findings back to Cambridge. The tone of the letters is very amiable giving an interesting and moving insight into Darwin’s experiences, an example being his excited reaction to being told he had been accepted on the expedition by Captain Fitzroy - ‘Gloria in excelsis is the most moderate beginning I can think of’!
Surface cleaning a letter
The letters were presented for conservation loose, having previously been taken out of their poor quality nineteenth century binding. Although the paper was a good quality, often large tears and losses were evident especially around the edges and wax seals. Various types of repairs had been added to the letters, and the paper tabs used to stitch the letters into the binding were still adhered to the letters, often obscuring the text. The main problem, however, was the degrading ink which was evident on all of the letters. Darwin had used iron gall ink – an ink which was used extensively throughout the nineteenth century but one which can, due to its components, ‘corrode’ the paper in and around the ink line.
Ink and paper loss due to ink corrosion.
Losses, as well as 'haloing' and 'strikethrough' of the ink were evident on the letters so stabilisation of the ink needed to take place in order for the writing to remain legible and to minimise further degradation of the paper support.
Absorption of UV light indicates the presence of iron gall ink. The visible presence of writing on the reverse side, during UV light investigation, indicates a risk of future ‘strikethrough’ of ink, if left in its current state.
All of the letters needed surface cleaning, and previous repairs and tabs had to be removed prior to treatment of the ink. After slow humidification to minimise movement and stress in the paper, the letters were immersed into a water bath and then into an aqueous solution of calcium ammonium phytate. Deacidification then took place in aqueous calcium bicarbonate and the letters were subsequently re-sized with gelatin. This procedure stabilised the ink and allowed for the necessary repairs to the letters to be adhered. Losses were infilled using a toned Japanese paper and tears were repaired so that all the writing was legible.
A batch of letters in the first bath of cold water
The letters were re-housed in a specially designed folder which allows for each letter to be viewed without the risk of any further damage. This was a fascinating project which allowed me to investigate the best way to preserve these important letters for the future whilst respecting their unique history. Thank you to the several generous individuals who made the conservation of these letters possible.
Letters in the leather bound folder after treatment
- Eleanor Hasler -
- Read the content of these letters in The Darwin Correspondence Project
- Kew's collection of letters written by Charles Darwin
- Find out more about the history of iron gall ink and ink corrosion
- The relationship between Darwin and Henslow
- The HMS Beagle Project Blog
- More information about Charles Darwin and John Stevens Henslow
- The Library, Art and Archives collections
About the Tropical Nursery
The main functions of the Nursery are to:
- Form a back-up collection of tender tropical plants used to support science, display and education within the gardens. We supply plants for use in displays in the Main Kew conservatries, for festivals and events organised by the Foundation and the Directorate.
- Supply plants for education purposes to the Schools & Families department.
- Act as main propagation facility for the Princess of Wales Conservatory, Palm House and Temperate House as well as supporting the exchange of plants between Kew and other institutions and collections.
- Provide direct education in nursery techniques and the cultivation of tropical plants for the Kew Diploma course, Apprentice and Trainee programme, Internship and work experience programmes and visiting staff from other UK and overseas institutions.
- Support conservation by working with the UKOTs team undertaking propagation and cultivation protocols on targeted endangered species.
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