Anal'ysis, the separation of anything into its elements. In philosophy it is the mode of resolving a compound idea into its simple parts, in order to consider them more distinctly and arrive at a more precise knowledge of the whole. It is opposed to synthesis, by which we combine and class our perceptions and contrive expressions for our thought so as to represent their several divisions, classes and relations. In chemistry, analysis is the process of taking apart a compound substance with a view to determine either (a) what elements it contains (qualitative analysis), or (b) how much of each element is present (quantitative analysis). Thus by the first process we learn that water is a compound of hydrogen and oxygen, and by the second that it consists of one part of hydrogen by weight to eight parts of oxygen.