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558 physical, which may affect the reproductive function. The book is an extremely satisfactory one and calculated to do much good.

is little enough to say of this textbook, by the most eminent of living geologists, that it is a most able and authoritative work. Its scope and characteristics were set forth in the notice of its first edition, in the twenty-second volume of this magazine. The present edition has been entirely revised, and in some portions recast or rewritten, so as to bring it abreast of the continuous advance of geological science. The additions made to the text, which extend to every branch of the subject, increase the volume by about one hundred and fifty pages. The position of the author as Director-General of the Geological Survey of Great Britain and Ireland has given him exceptional facilities for securing the utmost fullness and accuracy attainable in a geological treatise, and it is greatly to the credit of the British Government that it keeps such a man in such a place.

author states that eight of the thirteen chapters of this work have been previously published as lectures, addresses, or essays, but notwithstanding the desultory manner of their appearance there is a continuity in the subject matter, and the book has none of the characteristics of a collection of published papers.

He tells us that the title Rural Hygiene was chosen because it is only in places having a rural or semi-rural character that it is possible to be guided by scientific principles in our measures for the preservation of health and the prevention of disease. He considers that the hygienic arrangements in cities are the products of expediency rather than principle, and are not infrequently carried out in defiance of the teachings of pure science. He truly says that if the rural element be entirely banished from our towns, and if the fearful concentration of population that is seen in the modern city, both in England and America, be allowed to proceed unchecked, we are in a fair way to increase rather than decrease the liability of our towns to suffer from epidemics. He expresses the Utopian sentiment that before the nineteenth century closes people will begin to see the advantages not only of rural features in the city but also of urban features in the country.

In the first and second chapters, on the concentration of population in cities, it is insisted that this is an indirect effect of our modern sanitary methods, that give a fatal facility for the packing of houses in dangerous proximity to each other. It is shown that the retention of a rural element in rapidly developing towns, by allowing open spaces to exist between houses, has great advantages on the score of health as well as on that of finance.

Some of the shortcomings of modern sanitary methods are dealt with in the third chapter; such as the mixing of putrescible matter with water, that leads to the dissemination of water-borne diseases, to the pollution of rivers, and the poisoning of wells.

The fourth chapter, on the "living earth," shows that by virtue of the animal and vegetable organisms contained in humus it has the marvelous power not only of turning organic matter into food for plants, but of protecting the air and water from animal pollutions.

The many evils associated with what are known as modern sanitary fittings are reviewed in the fifth chapter, on the house. It is insisted upon that no house can be securely and permanently wholesome unless it have tolerably direct relations with cultivable land.

The sixth chapter discusses some of the elementary facts in regard to air as well as the relationship that exists between the earth and the air. The latter is freshened by vegetation, and when the air in cities becomes too foul to allow vegetation to flourish a danger to health is in existence.

The seventh chapter shows that, if we want pure water, a scientific and careful disposal of putrescible refuse is necessary; and the relations that exist between earth and water are discussed.

In the eighth, ninth, tenth, and eleventh