It is not possible for you to thoroughly understand or appreciate what I am to lay before you, in a description of our society in municipal life, without a further knowledge of some of our methods. One of the most important of these, is the perfection which we have brought to our science of statistics, and the indispensable service it is made to perform in our political economy. This branch of science is pursued by us as the most serviceable and practical of all. We learn from it in a positive way many truths which your economists fail to reach, and we have discovered by it many errors which have existed as the result of sophistical reasoning. We use it as a rule and square to measure the speculations of philosophy, as well as an every-day guide in the practical affairs of life. Its better value for us lies in the fact that our conclusions from it are adduced out of the records of centuries. It is to social science what analysis is to chemistry. It is only by a systematic and orderly record of the occurrences of nature, and the changes and events of society, that we have arrived at the many profound truths so deeply concerning our lives. By it we have discovered how astonishingly nature holds, concealed from common eyes, so many of her processes, coquetting with us, as it were, in withholding her greatest favors without prolonged and incessant interrogation. But although our store of scientific knowledge has been increased by these statistical labors, we hold them of no less importance in managing the practical affairs of life.