On the Microscopical Structure of Crystals: Indicating the Origin of Minerals and Rocks
(This book was originally published prior to 1923, and rep...)
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Henry Clifton Sorby was an English microscopist and geologist. His major contribution was the development of techniques for studying iron and steel with microscopes. This paved the way for the mass production of steel.
Background
Sorby was born on May 10, 1826 in Woodbourne, England. His father, Henry Sorby, owned a small cutlery factory; his mother was the daughter of a London merchant. He inherited a modest fortune after his father’s death in 1847 and thereafter devoted himself entirely to science while continuing to live in Sheffield, a flourishing steel manufacturing town somewhat limited intellectual resources.
Education
Sorby attended local schools, including Sheffield Collegiate School, and at age fifteen he won, as a prize for mathematics, a book entitled Readings in Science, published by the Society for Promoting Christian Knowledge (first edition 1833), which set the direction of his life. During the next four years he completed his education with a full-time private tutor, the Rev. Walter Mitchell, a competent scientist.
Career
Sorby started this work in 1849 with studies of sedimentary rocks.
In 1851 he became involved in a widely noticed debate on the origin of slaty cleavage, and in an 1853 paper he showed conclusively that cleavage was a result of the reorientationof particles of mica accompanying the deformation (flow) of the deposit under anisotropic pressure, Sorby later studied organisms in limestibe abd discovered the presence and Significance of microorganisms in chalk.
Of great importance was his 1858 paper on liquid inclusions in crystals, both natural and artificial. Inclusions in large crystals also had been observed by David Brewster and Humphry Davy in the 1820’s, but Sorby used the microscope to find abundant smaller ones within the microcrystals in many metamorphic rocks. He measured the size of the bubbles that resulted from liquid shrinkage after the cavity had been sealed, and he performed laboratory experiments to measure the expansion of liquids in sealed tubes under pressure that enabled him to deduce the temperature and pressure at which the rocks had been formed.
The 1858 paper was illustrated with 120 drawings made under the microscope at magnifications between 60 and 1, 600, transferred to the lithographer’s stones by Sorby himself. He concluded: “There is no necessary connection between the size of an object and the value of a fact, and. .. though the objects I have described are minute the conclusions to be derived from the facts are great. ” There were still eminent geologists who saw little good to come from studying mountains with microscopes, and Sorby’s work was rather slow to be widely appreciated.
On 28 July 1863 he recorded in his diary, “Discover the Widmannstättischm structure in iron. ” Sorby mentions “various mixtures of iron, two or three well-defined compounds of iron and carbon, of graphite and of slag; and these, being present in different proportions, and arranged in various manners give rise to a large number of varieties of iron and steel. Despite considerable interest at the time, no one followed this start. Earlier he had identified graphite and iron oxide in iron samples and had described the true nature of recrystallization and transformation: “Iron and steel are not analogous to simple minerals, but to complex rocks. ”
After 1885 people in many countries took up the new field. Four new elements had been discovered by emission spectroscopy since Bunsen and Kirchhoff’s announcement of 1860. Carotene was one of the discoveries, and his work on chlorophyll. He became involved in an unpleasant priority dispute and more embarrassment when, six months later, he had to retract, for he had found that the lines were due to uranium. Sorby advocated separation of research and teaching, and in the contribution “On Unencumbered Research - A Personal Experience, ” to Essays on the Endowment of Research (1876), edited anonymously by Charles Appleton for a group of scientists at Oxford, he used his own work as an example of the value of unencumbered and undirected - but not isolated - research.
In 1871 he had discussed the possibility of endowing a Royal Society professorship in experimental physical research that would be free from teaching duties. This was apparently the result of a quarrel with Cambridge biologists including Alan Sedgwick (great-nephew of the geologist of the same name), whose intolerant antireligious attitude disgusted him.
Beginning in 1880, Sorby worked to promote the formation of Firth College in Sheffield and served as its president from 1882 to 1897.
For the next five years he worked over the notes that he had accumulated throughout his life, returning to the geology that had begun his career and that resulted in a last major, although retrospective, paper on sedimentary rock formation.