ATOMIC WEIGHTS
When work was undertaken, to discover the exact atomic weights of these various elements, it was soon found that these could not be expressed in exact, whole numbers. Fractions or decimal numbers were nearly always found to exist. Thus, the atomic weight of Hydrogen was not exactly 1, but 1.008; copper was 63.57, etc. For long it was thought that these variations were due to errors of experiment, and renewed attempts were made to reach more accurate conclusions, in which these apparently annoying fractions were absent. But the most painstaking experimental work only served to confirm these results, and still later researches have shown us why this is so. It would take us too far afield, however, to go into that question at present.
The various elements were given symbols for the sake of brevity; some of these represented the first letters of the name of the element; some were the first letters of the Latin word for that element. Thus, Co = Cobalt, S = Sulphur, Ne = Neon, Bi = Bismuth. On the other hand, Fe = Iron (Latin, ferrum), etc. This served greatly to abbreviate chemical language, and at the same time simplified chemical formulæ and equations.