FOOTNOTES:
[13] "In reviewing once more the facts elicited by our inquiry, we find them arranged around a common centre, a group of atoms preserving intact its nature, amid the most varied associations with other elements. This stability, this analogy, pervading all the phenomena, has induced us to consider this group as a sort of compound element, and to designate it by the special name of benzoyl."—Liebig and Wöhler, 1832.
[14] "Animal Chemistry, or Chemistry in its Applications to Physiology and Pathology," 1842. "Researches on the Chemistry of Food," 1847. "The Natural Laws of Husbandry," 1862.
CHAPTER VII.
MODERN CHEMISTRY.
On p. 162 I referred to the work of the German chemist Richter, by which the equivalents of certain acids and bases were established. Those quantities of various acids which severally neutralized one and the same quantity of a given base, or those quantities of various bases which severally neutralized one and the same quantity of a given acid, were said to be equivalent. These were the quantities capable of performing a certain definite action.
In considering the development of Dumas's substitution theory, we found that Laurent retained this conception of equivalency when he spoke of an equivalent of hydrogen being replaced by an equivalent of chlorine (see p. 272). A certain weight of chlorine was able to take the place and play the part of a certain weight of hydrogen in a compound; these weights, of hydrogen and chlorine, were therefore equivalent.