Lavoisier, together with Louis-Bernard Guyton de Morveau, Claude-Louis Berthollet, and Antoine François de Fourcroy, submitted a new program for the reforms of chemical nomenclature to the Academy in 1787, for there was virtually no rational system of chemical nomenclature at this time. This work, titled Méthode de nomenclature chimique (Method of Chemical Nomenclature, 1787), introduced a new system which was tied inextricably to Lavoisier's new oxygen theory of chemistry.
The classical elements of earth, air, fire, and water were discarded, and instead some 33 substances which could not be decomposed into simpler substances by any known chemical means were provisionally listed as elements. The elements included light; caloric (matter of heat); the principles of oxygen, hydrogen, and azote (nitrogen); carbon; sulfur; phosphorus; the yet unknown "radicals" of muriatic acid (hydrochloric acid), boric acid, and "fluoric" acid; 17 metals; 5 earths (mainly oxides of yet unknown metals such as magnesia, baria, and strontia); three alkalies (potash, soda, and ammonia); and the "radicals" of 19 organic acids.
The acids, regarded in the new system as compounds of various elements with oxygen, were given names which indicated the element involved together with the degree of oxygenation of that element, for example sulfuric and sulfurous acids, phosphoric and phosphorous acids, nitric and nitrous acids, the "ic" termination indicating acids with a higher proportion of oxygen than those with the "ous" ending.
Similarly, salts of the "ic" acids were given the terminal letters "ate," as in copper sulfate, whereas the salts of the "ous" acids terminated with the suffix "ite," as in copper sulfite.
The total effect of the new nomenclature can be gauged by comparing the new name "copper sulfate" with the old term "vitriol of Venus." Lavoisier's new nomenclature spread throughout Europe and to the United States and became common use in the field of chemistry. This marked the beginning of the anti-phlogistic approach to the field.