1778 in science

The year 1778 in science and technology involved some significant events.

Astronomy

 * Lagrange delivers his treatise on cometary perturbations to the Académie française.

Chemistry

 * Molybdenum discovered by Carl Wilhelm Scheele.
 * Antoine Lavoisier, considered "The father of modern chemistry", recognizes and names oxygen, and recognizes its importance and role in combustion.

Earth sciences and exploration

 * January 18 – On his third voyage, Captain James Cook, with ships HMS Resolution and HMS Discovery, becomes the first European to view the Hawaiian Islands in the Pacific Ocean.
 * March 6 – October 24 – Captain Cook explores and maps the Pacific Northwest coast of North America from Cape Foulweather (Oregon) to the Bering Strait.
 * James Rennell publishes a chart and memoir of the Agulhas Current, one of the first contributions to scientific oceanography.

Medicine

 * John Hunter publishes The Natural History of the Human Teeth.
 * Samuel-Auguste Tissot begins publication of Traité des nerfs et de leurs maladies, including a classical account of migraine.
 * Samuel Thomas von Sömmerring describes the organization of the cranial nerves.
 * Publication of Collection of observations on diseases and epidemic constitutions (Collection d’observations sur les maladies et constitutions épidémiques), by Louis Lépecq de La Clôture, work consisting mainly of a 15-year observation of the relations between climate, geography and pathologies in Normandy.

Technology

 * Joseph Bramah patents an improved design of flush toilet in London.
 * The brothers Hans Ulrich and Johannes Grubenmann complete a bridge across the Limmat at Wettingen in Switzerland, a 60 m span which is the first known use of a true arch in a timber bridge.

Zoology

 * Petrus Camper publishes On the Points of Similarity between the Human Species, Quadrupeds, Birds, and Fish; with Rules for Drawing, founded on this Similarity, an early work of comparative anatomy.
 * Johan Christian Fabricius publishes his Philosophia Entomologica in Hamburg.

Awards

 * Copley Medal: Charles Hutton

Births

 * February 4 – A. P. de Candolle, Swiss botanist (died 1841)
 * May 18 – Andrew Ure, Scottish industrial chemist and encyclopaedist (died 1857)
 * December 6 – Joseph Louis Gay-Lussac, French chemist and physicist (died 1850)
 * December 17 – Humphry Davy, English chemist (died 1829)
 * December 25 (bapt.) – Joseph Aspdin, English inventor (died 1855)
 * Maria Dalle Donne, Bolognese physician (died 1842)
 * Anna Maria Walker, Scottish botanist (died 1852)

Deaths

 * January 10 – Carl Linnaeus, Swedish botanist, first to develop standard nomenclature for naming species (born 1707)
 * February 20 – Laura Bassi, Italian scientist (born 1711)
 * March 7 – Charles De Geer, Swedish industrialist and entomologist (born 1720)
 * May 6 – Jean Baptiste Christophore Fusée Aublet, French pharmacist and botanist (born 1720)