Sorby Slides
What are the Sorby Slides?
These are a collection of 'lantern slides' that preserve marine specimens collected by Sorby on his expeditions around the British coast.
Sorby began his marine expeditions in 1879 when he purchased a large yacht 'Glimpse' which he transformed into a floating laboratory to study the diversity of coastal life in British seas.
While appearing as 2D photos, these slides actually contain mounted specimens, squashed between two layers of thin glass - a technique he pioneered.
The process of mounting specimens involved the use of Canadian balsam, a common mounting medium in microscopy- which appears yellow when specimens are not fully sealed. You can see how Sorby develops his technique from observing the slides. Some are completely sealed around the edges with a black paper mount, whereas some were less successfully sealed and as a result have a yellow-stained colour.
About lantern slides:
Lantern slides originated in the 17th centaury and were used to display images with an early type of image projector the Magic Lantern. They usually contained prints, photos, diagrams and paintings to be displayed for home entertainment, lecture material and photographic exhibitions.
Within the museum we hold an assortment of slides containing pictures, diagrams, illustrations and more.
Sorby preserved specimens so they could be used as lantern slides with a projector. Sandwiching them between glass without distorting the organisms. Allowing them to be displayed on a large screen for study at his popular public lectures.
We have a collection of lantern slides used by various teaching staff at the University. Most of our slides are attributed to 'J.E. Atkinson'. Others are signed off by 'B H Bentley'- Prof. Bertram H. Bentley who was appointed Lecturer in Biology at Firth College in 1897. In 1908 Bentley became Lecturer in Charge of the newly created Department of Botany at the University of Sheffield, appointed Professor of Botany in 1931.
Sorby's specimen slides
Sorby's specialised technique of mounting organisms focused on preserving high resolution details and encapsulating the 3D nature of the organisms even while flattened between glass. He achieved incredible detail using a variety of dyes to highlight the different organelles visible in many of the translucent species.
He often brought these slides to his natural history lectures to be used with lantern projectors.
For many that visited his talks, this was the first time they learnt about the marine invertebrates and algal specimens he displayed.
He used these specimens to highlight the unique diversity that is often overlooked due to its small size, or inaccessibility for many to survey the ocean.
Many of the specimens have been preserved with specific dyes highlighting structures within their body and increasing opacity of translucent organisms.
Where can the slides be found?
Some of the original slides are shown in a wall mounted light-up display outside the museum on C floor. The rest of the collection is held in the archives of the Alfred Denny Museum and other museums in Sheffield.
There is also large picture display named 'Wonder' outside of the museum which contains photographs of both the lantern slides used in zoological teaching in the department and Sorby's preserved specimen slides.
Who was Henry Clifton Sorby (1826-1908)
H.C. Sorby is one of the greatest minds to come from Sheffield. He was a pioneer in the use of microscopes for scientific study and made significant contributions to the fields of of geology, crystallography, metallurgy and marine zoology. He is considered to be one of the last independent scientific amateur: those who peruse science for the love of it, supported by their own means, investigating elements no one had thought to.
He boasts many achievements and scientific prowess in a number of different fields. Publishing over 200 papers in his lifetime on a variety disciplines such as: chemistry, metallurgy, marine biology, archaeology and geology. He pioneered many microscopic techniques and laid the foundations of microscopic petrology (the study of the structure and composition of rocks) and modern metallography (the study of microstructures and components of metals and alloys).
Named as the 'Father of Microscopical Petrography' by the Geological Society, a 'leading expert on Metallurgy' and elected as a Fellow at the Royal Society for his geological work (aged just 31) it is evident that Sorby was an incredibly talented scientist with a wide range of expertise.
In addition to his research pursuits Sorby was also a founding member of the University, playing an incremental role in gaining it's Royal Charter in 1905.
Sorby and the university:
Sorby had a keen interest in education and took a leading part in an unsuccessful attempt to found a Technical School in Sheffield in the 1860s.
His efforts to set up and oversee educational facilities continued as he joined Firth College as its Vice- President in 1881 soon after its establishment. He then went on to be President from 1882-1897, and became instrumental in the efforts to establish a University, using his wealth to purchase land surrounding Firth Court while serving as Vice-President of the new University College, Sheffield, 1897-1905.
With the inauguration of the University of Sheffield in 1905 he served as a member of its Council until his death on 9th March 1908.
Access to education:
Sorby did not have a university education. No university at the time offered purely scientific courses that suited his range of interests. Instead he developed his scientific interests through groups such as the Sheffield Literary and Philosophical Society and Yorkshire Geological & Polytechnic Society which offered lectures and forums to discuss scientific ideas.
He was motivated by the spirit of original investigation and never sought the attention that his achievements merited. His averseness to specialisation led to criticism by some of his contemporaries in the scientific establishment. They suggested that he merely ‘showed the way’ rather than exhausting the possibilities of a discovery.
Sorby believed education should be more accessible and available to those outside of specialist institutions. As a result he hosted many public lectures covering a range of topics, due to his wide range of specialities. These lectures hosted up to 600 people per night, and were often filled to the brim.
Other items in the Sorby Collection:
As well as the Sorby Slides we hold a number of Sorby's instruments and relevant items from his life, some of which are on display in the C-floor cabinet dedicated to Sorby's work.
In addition to the items held by the Museum, the University of Sheffield Library contains an assortment of records, diaries, copies of Sorby's work and more.
Items in the museum include:
The address from the Geological Society (dated 1907) honouring Sorby as the 'Father of Microscopical Petrography'
Specimen cabinet of geological samples including volcanic ash from the famous Krakatoa 1883 eruption
Presentation case of metal specimens mounted in preparation for microscopic study
Multiple specimen boxes containing thin sections of rock, some ground (by hand) to one-thousandth of an inch thickness.
Specimens of marine fauna collected on his journey's on the coast of East Anglia. (These specimens are currently on loan from the Sheffield City Museum)
Fossils collected from multiple locations in the UK such as Cheltenham, Bath, Bristol and the Sussex Coast.
