Background
Samuel Edward Sheppard was born in 1882 in Kent, United Kingdom.
University College London
the Philipps University of Marburg
The front of the Sorbonne Building
Samuel Edward Sheppard was born in 1882 in Kent, United Kingdom.
Samuel Sheppard attended a preparatory school at Deal, in Kent, and later a technical school, St. Dunstan's College, at Catford, Kent. There he was a classmate of Charles Edward Kenneth Mees, with whom he was to maintain a close professional relationship for most of his life. The two went on in 1900 to University College, London under the chemist Sir William Ramsay. Ramsay was a strong advocate of granting degrees for research, and Sheppard and Mees were the first students admitted on this basis. Their preliminary results earned each man a Bachelor of Science in 1903, and, following three years of further research, each received the D. Sc. in 1906. His and Ramsay's findings were published as Investigations on the Theory of the Photographic Process (1907).
With the aid of an 1851 Exhibition Scholarship, Samuel Sheppard continued his research in photochemistry at the Philipps University of Marburg in Germany, under Franz Richarz and Karl Schaum, and at the Sorbonne in Paris under Victor Henri. At both institutions, he studied the sensitizing action of dyes, particularly the new isocyanine and carbocyanine dyes. Henri stimulated his interest in colloid chemistry.
Samuel Sheppard and Mees joined the photographic manufacturing firm of Wratten and Wainwright in Croydon, in Surrey, and in 1910. Both men left in 1912, Mees to head the new Kodak Research Laboratory at Rochester, New York, at the invitation of George Eastman, and Samuel Sheppard to enter the School of Agriculture at Cambridge University in pursuit of an earlier interest in agricultural chemistry. The following year, however, Mees called Sheppard to Rochester to join the new laboratory as a colloid and physical chemist. He was to remain with the Kodak Laboratory until his retirement in 1948, becoming chief of the departments of physical, inorganic, and analytical chemistry in 1920, and, four years later, assistant director of research.
Sheppard's work can be grouped into nonphotographic and photographic categories. He found that coal powder, a waste product from handling coal, could be dispersed as a stable suspension in fuel oil, by the use of resin soaps, to the extent of 40 percent, adding its fuel value to that of the oil. In 1921 Samuel Sheppard turned his attention to the electroplating of rubber and rubber compounds; his patents and processes were consolidated with those of others in the American Anode Company. He also developed concepts on the relationship between chemical constitution and colloidal behavior which involved studies of the viscosity, plasticity, and elasticity of solvated colloids, such as cellulose esters, gelatin, and rubber; studies on the work of adhesion at solid-liquid interfaces; and studies on thin film formation.
In his first five years at the Kodak Laboratory, Samuel Sheppard was mainly concerned with the physicochemical properties of gelatin, the medium that contains the sensitive materials in photography. He measured the viscosity of gelatin in solution, its strength, elastic properties, setting and melting points, and drying and swelling of gelatin in the jelly and dry states. This work led in 1929 to a procedure for making standardized gelatin. It was known that different gelatins produced emulsions with differing sensitivity. By systematic study and painstaking analysis, Samuel Sheppard found that traces of labile organic sulfur bodies in gelatin were the cause of high sensitivity. This led to direct sensitizing of the emulsion by means of a related compound, allylthiourea, and to the discovery that the "foreign substance" produced and giving the sensitivity was silver sulfide as minute specks in the silver halide crystals.
Sheppard's later research dealt with a wide range of matters, including photovoltaic effects (the electrical response of silver halide to light), the physicochemical properties of the film supports, the nature of development and of dye sensitizing, and absorption of dyes to crystals and their absorption spectra in relation to the resonance structure of the dyes.
In his last few years, Samuel Sheppard lost the sight of one eye from glaucoma and suffered from heart trouble. He resigned his laboratory post in January 1948, and died later that year in Rochester, at the age of sixty-six.
Samuel Sheppard was fluent in several languages, including Latin. Socially, he was a charming, tolerant companion.
On November 27, 1912, Samuel Sheppard married Eveline Lucy Ground, of Wisbech, Cambridgeshire, England. They had one child, Samuel Roger.