NOTES:
a: Early Greek preoccupation with philosophic approaches to understanding matter and processes probably involved scant basis in physical experiment due to association of such physical work with the work usually consigned to slaves.
b: "iatrochemistry" ("iatros" = physician (Greek)) involves the application of chemistry (however primitive) to medicine.
c: "calcination" means conversion to a powder (oxide?) by strong heating or burning.
d: "pneumatic chemistry" involves physical measurements done upon various gases.
e: electrolysis using Volta's "Pile" (or battery) was a new technique in the early 1800's; Davy used electrolysis to obtain alkali metals and alkaline earth metals for the first time.
f: Berzelius' (1812) Dualistic Theory was based upon research in electrolysis. Chemical combinations were thought to result from electrical (charge) attraction of opposite charges. Metals were electropositive; metal compounds involve negatively charged ions that are not necessarily equal (but opposite) in charge. This possible inequality allows attraction between zinc oxide and sulfur trioxide which leads to formation of zinc sulfate; formation of hydrates is possible with exposure of salts to water due to the residual charge (polarity?) on the salt and in water . Attempted application (1830's and 1840's) of the Dualistic Theory to organic chemistry was generally unsuccessful, resulting in the demise of the theory.
g: a "radical" can consist of an atom (ion?) or combination of atoms which can survive reaction or might be replaced by a single atom. The symbol for a radical, "R", continues to be used. Lavoisier described acids (actually anhydrides) as combinations of a radical with oxygen. The Radical Theory generally described compounds (even organic compounds) as combinations of radicals.
h: Lavoisier described acids (actually anhydrides) as combinations of a radical with oxygen.
i: Valence, a measure of combining capacity of an element or radical; sometimes described in terms of the number of hydrogen atoms with which an element or radical can form a compound or replace.
j: Bohr atom consists of a positively charged nucleus and electrons in concentric circular orbits around the nucleus.
k: "Type Theory": a modification by Laurent of the Radical Theory in which the possibility of modification (during reaction) of the radicals is proposed, resulting in "derived radicals".