Preface: Every science must have its special vocabulary or terminology. Sciences deal with ideas, thoughts, and concepts, and these must be expressed in words. Even the facts which are the groundwork of science must be set forth largely in words. No science, therefore, can have any more precision and exactitude than the words or other symbols, such as mathematical or chemical formulae, in which it is embodied. Quite generally, this situation calls for a special dictionary or glossary for each particular science.