Special and local names may well be noted on all main cards and cross references made in every case from such forms. For instance, the law governing the sale of stocks recently passed in Kansas, which is popularly known as the "Blue sky law" should be noted as such in the catalog. The "Mary Ann" bill may be called for by that name and if there is no cross reference in the catalog the untrained assistant in the library, or the stenographer, will never find it. The mechanical part of the catalog should be so complete that it does not require acquaintance with all phases of the subject in order that a person may use it intelligently. Therefore, special and local names inevitably need attention. The contents of a legislative reference library are largely of either an economic or a legal nature, and its patrons sometimes approach the material from the legal side and sometimes from the economic side. In assigning subject headings this fact must never be forgotten. Consequently, the headings will sometimes take a legal turn and sometimes an economic turn. At times it is necessary to compromise and choose one halfway between the two. Let us consider for a moment the relationship of the economic and the legal material. Justice Holmes, in his book on the "Common law," expresses this relationship unusually well. He says in substance that the growth of the law is legislative; it is legislative in its grounds; that the secret root from which law draws all the juices of life is consideration of what is expedient for the community.