In the Conservation Studio

Marion Gouriveau was our most recent conservation intern, and in this post she takes us through two of the fascinating conservation projects she worked on while here at the Special Collections Centre. Marion is working towards a Masters degree in conservation-restoration at the University Paris 1 Panthéon-Sorbonne.

While at the University of Aberdeen I worked on several projects including a miniature book and an anatomical model of a snail, made of papier-mâché. The book was a 1601 copy of De tranquillitate animi, written by Seneca (ca. 4 B.C-65 A.D), and the snail had formerly been used as a teaching aid and is now part of the Zoology Museum collection.

Miniature Book: De tranquillitate animi (shelf mark: pi 87265 t)

I worked on this project with Brannah Mackenzie, book conservator at GCC.

Description

This little book was printed and published in 1601. It has a leather binding and its dimensions are small: 40 mm high, 40 mm wide and 15 mm deep. The binding has been decorated using a method called tooling, where hot metal tools are used to make impressions into the leather. Both the front and back of the binding are also decorated with the letters “I S” and a fleur-de-lys in gold. The text block is made up of multiple paper gatherings sewn on two cord supports which are laced in to the boards. The text is printed in black ink.

Book before treatment: binding
Book before treatment: binding
Book before treatment: text block
Book before treatment: text block

Condition

The book was in poor condition. The boards were still attached to the text block and the board edges and corners were in quite good condition. However, the leather at the top and bottom of the spine was missing and the leather was slightly worn and abraded. There were also missing areas, ingrained dirt, tears and creases throughout the text block, especially to the pages where the sewing was broken. These pages were brittle and the title page was very soft.

Spine before treatment
Spine before treatment
Broken sewing & detached sections
Broken sewing & detached sections

I compared the original text of De tranquillitate animi with the text of the book and I realised that pages 96 to 193 were missing – probably always missing as there is not enough space in the binding to accommodate so many folios. Using the original text, I was also able to place a loose page in the correct location. The main concern with the book in this condition was that the detached sections could be lost. The treatment aimed to stabilise the binding and the text block to make the book suitable for use.

Treatment

The first step was to clean the surface. A smoke sponge made of vulcanised rubber was used to clean the binding and brushes were used to clean the text block. The title page had to be cleaned very carefully because it was so fragile. To prepare the leather for repair it was consolidated with an adhesive which strengthened the leather and helped to prevent it turning black when paste was applied to it. The next step was to dismantle the back half of the text block, which was the one in worst condition, in order to make paper repairs. Paper repairs were made with very lightweight Japanese tissue called Tengujo (11 gsm) and wheat starch paste. To be as precise as possible, I worked on the light box so I could see the damaged areas more clearly.

Binding after damaged sections have been removed
Binding after damaged sections have been removed
Working on a lightbox reveals areas requiring repair
Working on a lightbox reveals areas requiring repair
Repair paper applied
Repair paper applied
Repairs complete, ready for resewing
Repairs complete, ready for resewing

In order to find the best method to re-sew the half of the text block which had been dismantled, several tests were made using different types of stitch.

Models prepared to identify the most suitable sewing technique
Models prepared to identify the most suitable sewing technique

The best solution was the Coptic stitch, so called as it was used in Coptic bindings. It was felt that the linen thread, usually used for sewing text blocks, was too hard for the delicate text block, so we used a 100% cotton embroidery thread instead.

Re-sewn section in situ
Re-sewn section in situ

To further hold all the sections together, the spine was lined with a Japanese tissue and a piece of toned Japanese tissue was used to reinforce the spine and also repair the missing areas of leather.

Toned Japanese tissue attached underneath the spine leather
Toned Japanese tissue attached underneath the spine leather

The last step was to re-attach the board to the text block with a ‘v-hinge’ of Japanese paper.

V-hinge used to attach the board to the text block
V-hinge used to attach the board to the text block
Repairs dried under light pressure
Repairs dried under light pressure

The text block is now stable, and the book is suitable for production to readers.

After treatment
After treatment
After treatment
After treatment

Storage

To protect the book it was put in a four-flap box. The book is really tiny and so, to protect it more and to facilitate its storage, I made a bigger box, where the book is kept with the original sewing-threads, which were encapsulated in Melinex. 9. Storage (1) The box is fitted out with Plastazote foam to prevent the book and the encapsulation from moving around inside the box. 9. Storage (2)

Anatomical Model of a Snail

For the second project I describe here, I worked with Caroline Dempsey, archaeological artefacts conservator, Marischal College.

Snail before treatment
Snail before treatment

Description

This model was made during the 19th century by Louis Auzoux, a French doctor born in 1797 who studied medicine in Paris. His factory offered a wide catalogue, producing models of the complete human body, animals, insects and plants. These models are called clastic models, from the Greek Klastos, which means broken or in pieces; they could be taken apart in order to access the internal organs.

Dismantled snail
Dismantled snail

The different parts are held together with metal pins and hooks. Each section is composed of several layers of paper pressed into metal lined wooden moulds. These are then filled with a pulp composed of flour starch paste, shredded paper, hemp fibre, lime and Poudre de Liège or powdered cork. Where pieces are hollow they are strengthened by additional layers of paper, and no pulp fill is added. When the basic structure is dry, arteries, veins and nerves composed of wire covered by hemp and paper are added and fastened with nails. Finally, the paper is painted with pigments bound in fish glue and a layer of gelatine applied as a varnish. Printed paper labels with numbers and little hands aid dismantling and reassembly.

Printed label with numbers and pointer to aid assembly
Printed label with numbers and pointer to aid assembly
Some sections are hinged together using small rings
Some sections are hinged together using small rings

This particular model of a garden snail belongs to the University’s Zoology collection. It is 66.5 cm length, 27 cm height and the shell is 27 cm width. We can’t be precise about the date, but there is a similar snail in France dated 1882 and another one dated 1855 in Leiden (Museum Boerhaave), Nederland. It can be dismantled into 15 pieces. Some parts are kept together with rings, others can be opened thanks to hinges.

Condition

On examination, the snail was in poor condition. Its age, exposure to light and changes in relative humidty (RH) had caused the paint and the adhesive to crack, especially along the edges. It had been particularly affected by the fluctuations in RH, having previously been stored in close proximity to a plant room. It is also believed to have suffered from smoke damage as a result of a fire in the University’s Zoology Department a number of years ago. The papier-mâché suffered from distortion and delamination and some metal parts such as iron hooks and clasps, used to attach the various components, were corroded. A membrane of goldbeater’s skin (a lightweight material made from animal intestine) was detached from the structure representing the pulmonary arteries. There were many losses, the surface was very dirty, and one of the antennae was missing.

Cracked and flaking paint
Cracked and flaking paint
The pulmonary arteries section with detached and distorted goldbeater’s skin covering
The pulmonary arteries section with detached and distorted goldbeater’s skin covering

Treatment

Some work had been carried out by a previous conservator to prepare the snail for exhibition. With limited time available, the primary aim at that point was to stabilise the item so that it could be handled safely for display purposes. However, this was by necessity a short-term solution and additional stabilising treatment to reduce risk of further damage in the longer term was required.

The first step in this second stage of treatment was to clean the surface. The snail had previously been cleaned with saliva which contains enzymes that can be helpfully used to breakdown more tenacious dirt. I attempted to reduce the dirt further through the use of iced water. As reported by Richard Barden, a conservator at the National Museum of American History, the use of iced water reduces the risk that the gelatine contained in the coating will soften.

Once one area was cleaned, I worked on re-attaching the flaking paint. Water was first used to humidify the paint layer just enough to facilitate manipulation so that it could be re-adhered, edge to edge. In some cases additional strengthening of repairs was required and in these cases, a Japanese tissue was added. Where sections of paint were missing, the gap was filled in with Japanese paper of different thicknesses, until it had the same level as the paint. If necessary, the Japanese paper was either toned before application or in-painted after. The idea here was not to make the repair invisible, but to make it less intrusive. It is important to be able identify what is new and what is original.

Before
Before
After
After
Area of loss before treatment
Area of loss before treatment
Layers of Japanese tissue applied
Layers of Japanese tissue applied
Dried under pressure
Dried under pressure
Area after treatment
Area after treatment

Iron parts were cleaned with an abrasive fibreglass pencil, in order to remove the corrosion, and prevent more alteration to the paper.

Repair to the Pulmonary Arteries

One of the most challenging areas to address was the damage to the pulmonary artery piece. The membrane of goldbeater’s skin is extremely hygroscopic meaning that it responds readily to the amount of water in the atmosphere. Over time repeated expansion and contraction has led to this membrane distorting, tearing and detaching from the structure beneath.

Due to time constraints, it was decided that the area would be stabilised through the use of tabs to attach the membrane remnants to the structure beneath. First the goldbeater’s skin was humidified and flattened locally, then tabs were attached to keep the skin in place. The tabs were applied to the outer side to minimise the risks associated with applying them securely inside the structure, and it was therefore important that when applied, they would be unobtrusive. In addition to this, the adhesive selected had to be strong enough to maintain attachment to the goldbeater’s skin once dried. I carried out a number of tests to find the most appropriate solution.

Before humidification and tab repair
Before humidification and tab repair
After humidification and tab repair
After humidification and tab repair

While this treatment succeeded in stabilising this section in the short-term, further issues require resolution before a long term solution can be applied.

What next?

While work is not complete, the benefits of the treatments carried out can already be seen. The work on the paint and varnish layers means that the snail can be re-assembled more easily and with less risk than before. However, a few problems are still to be resolved: for example, how should missing metal pins be dealt with? What is the best long-term solution to the repair of the pulmonary arteries?

This project is therefore ongoing, and it is planned that work will be continued by another placement student who will continue with the testing and treatments that I have begun.

My work on the snail has formed the basis of my final dissertation where I also explain the methods and technology used by Auzoux to make these models in papier-mâché, and briefly present the history of the anatomical model. The purpose is to understand the historical and technological background of these objects. Why were they created? Where are they kept now?

After four months spent at the University of Aberdeen, I have moved on to my next placement. In order to further develop my understanding and to bring greater precision to my work on papier-mâché models, I will be working on an anatomical model of a man, held in the Medicine Museum, in Brussels, Belgium: http://www.museemedecine.be/

A PDF report with some additional technical details can be downloaded here: Full report

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click to replay snail assembly
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