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'Johann Heinrich Schultz' (
★ 12th May 1687 in Colbitz; † 10th October 1744 in Halle), also known as Johann Heinrich Schulze, was a German professor and universal scholar.

Contents

History

Notable discoveries

See also

References

External links

History

Schultz studied medicine, chemistry, philosophy and theology and became a professor in Altdorf and Halle for anatomy and several other subjects.

Notable discoveries

Schultz is best known for the discovery that certain silver salts, most notably silver chloride and silver nitrate, darken in the presence of light. In an experiment conducted in 1724 he determined that a mixture of silver and chalk reflects less light than untarnished silver. Though his discovery did not provide the means of preserving an image - the silver salts continued to darken unless protected from light - it did provide the foundation for further work in fixing images. The first permanent photograph based on this principle was made in 1826 by Joseph Nicéphore Niépce in Paris. Other researchers in this field included Thomas Wedgwood and Sir Humphry Davy.

See also

★ Medicine

★ Chemistry

★ Philosophy

★ Theology

References

External links