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Senate House Library

The Science Behind The Magic


Written by
Yunsun Choi

With our ‘Staging Magic – The Story Behind The Illusion exhibition and the upcoming ‘Smoke and Mirrors: The Psychology of Magic exhibition at Wellcome Collection, Bloomsbury is full of magic and mystery. Much like the great Victorian researchers and investigators who have gifted their books and items, the Conservation Team here at Senate House Library have been hard at work, using science to explore and preserve these magical mysteries.

To Lend or Not to Lend? That is the question…

This question was provoked by the Wellcome Collection’s request to borrow Eric John Dingwall’s ‘Haunting and Poltergeist Investigation Toolkit’ from Senate House Library for their exhibition. It’s a fascinating object which shows how science was used to investigate claims of the paranormal. It contains a notebook; coloured, silver and tissue papers; luminous strips and cards; luminous pins; string, threads and wire; a tape measure; a compass; tweezers; wax; chalk; pencils; bulbs; a brush; seeds; weighing measure, various bottles and cotton wool. Also included is a black and white photograph of medium Willi Schneider dated 1924 and a note by Dingwall including the comment, "This is E.J. Dingwall's box of necessities for haunting and poltergeist investigations, an idea later borrowed by Harry Price who pretended it was his idea.....".


This item was the world’s first ‘ghost detective kit’ and was entrusted to Senate House Library, University of London, by none other than Eric John Dingwall himself. Dingwall was a mid-twentieth century British anthropologist and psychical researcher. Dingwall was seen as a controversial figure because he also worked as assistant keeper in the British Museum cataloguing material on erotica (and wrote popular books on sexology, resulting in the nickname ‘Dirty Ding’).  There was much competition between him and his contemporary Harry Price (as you can see from the description of the note in the ‘ghost detective kit’), who was also a British psychical researcher and whose collection was donated to the university in 1936, provides the content for the Staging Magic exhibition.

The fascinating history of this unique item, means that it is of great interest and demand but the concern about lending the item stems more from its condition. The leather case is suffering from ‘red rot’ and the lid is completely detached. However, the inside of the box and contents is in good condition and has not been disturbed. So, although the leather box is in poor condition, it performed its role and protected what was contained within.

It is a fact that items are most vulnerable when handled and moved, whether an item is in good condition or not. However, does this mean that should not be handled and moved at all?  Collections will last longer and be safer if we put them in a dark, cool and dry (relative humidity of 40 ± 5 %) environment, and even better if the storage condition has low oxygen.  But then what is the point of having these items? In the end, a collection only has value if the collection can be viewed and researched by public. Additional value for the collection can be gained by lending items to other organisation, further justifying the collection’s existence and its significance in a wider heritage setting.

Science and innovation at work

So what is ‘red rot’? Red rot is acid deterioration of vegetable tanned leather from the mid-19th century onward. The leather becomes brittle, powdery and the red powder is transferable to anything and everything that it touches. Red rot can be treated, for examples, by conservation leather specialist at the leather conservation centre in Northampton, where treatment includes reducing the acidity of the leather and stabilising the collagen fibres. However, the long term prognosis for the treated leather is not currently available.  Any conservation treatment carry out can only slow down the degradation process and not stop it. Also such treatment comes at a cost.


An alternative that has been used in the past was that a conservator would apply either leather dressing or Klucel G in an effort to consolidate the powdery leather surface.  Fortunately, we now know that such treatment had a detrimental impact on the leather. It concealed the degrading product within the leather structure, accelerating the deterioration process, making the leather degrade faster, and further damaging the item.

Beyond the problem of red rot, the other issue with the leather box is that the lid is now completely detached and the box is in structurally poor condition. This prompted the debate that the lid should be re-attached prior to lending. Without re-attaching lid to the box the item should be deemed unsafe to travel or being handled. But is this true? 

Treating this particular item by re-attaching the lid and consolidating the poor structure prior to lending sounds logical. However, we now better understand that treating items is not always the best option.  Treatment involves adding new materials to older materials such as glue, new leather and paper etc. and also involves the movement and manipulation of the item regardless how carefully the treatment is carried out.  Any additional materials, regardless of how small and unnoticeable to the naked eye would change the true nature of the item.

Magic on the move


Any items leaving Senate House Library are thoroughly checked by a conservator to record the condition of the item prior to movement and a condition report produced. The item will then be packed and transported by a professional art transport company.  Prior to installing the item in its exhibition space, conservators in that institution will again condition check the item against the original condition report prior to transportation. A vulnerable item can be displayed if supported by appropriate exhibition furniture designed specially to support that item to prevent further damage during display. The surrounding environment must also be controlled and monitored.

After much exploration of all the conservation options, we decided to lend Eric John Dingwall’s ‘Haunting and Poltergeist Investigation Toolkit’ without treatment but taking every precaution to preserve and protect the item in its current condition at the Senate House Library. This could only have happened through the successful cooperation and trust between two institutions, involving the close team work between conservators, registrars and art-handlers.

Explore the science behind the magic for yourself by combining a visit to see the ‘world’s first ghost detective kit’ on display at the Wellcome Collection ‘Smoke and Mirrors: The Psychology of Magic’ exhibition (11 April - 15 September 2019) with a visit to Senate House Library’s exhibition Staging Magic – The Story Behind The Illusion (ends on 15 June 2019). Here you can see over 80 magic books from the Harry Price collection, including a rare first edition of one of the first books on magic in the English language dated 1584.

About the author

Yunsun Choi

Senior Conservator, Senate House Library