Page:Popular Science Monthly Volume 27.djvu/137

Rh effect. The author has, therefore, devoted his attention almost entirely to the explanation of principles, to the exclusion of mechanics. He has aimed to exhibit the identity of all the forms of electricity, and has accordingly so arranged the matter of his treatise that each succeeding form shall appear to flow naturally from its predecessor. For the biographical sketches, those men have been selected whose discoveries have added most to the science; and the sketches are so distributed that each one shall be in logical juxtaposition with those branches of the science that have been most conspicuously illustrated by its subject. In the several chapters are given explanations of magnetism; the "Mariner's Compass," statical and atmospheric electricity, galvanism and galvanic batteries, electro-chemical decomposition, electrotyping and gilding, electro-magnetism, the electric telegraph, magneto-electricity and dynamos, the storage of electricity, the telephone, the aurora borealis, and Faraday's observations on table-moving. The subjects of the sketches are Faraday, Franklin, Galvani, Volta, Oersted, Ampère, and Professor Morse.

subject of this primer is a most important one, especially in view of the frightful rate of infant mortality that prevails, largely the result of ignorance and carelessness. The author is a most competent person to discuss it. Her purpose, she says, is "to supply, in the simplest and easiest possible way, the few leading facts respecting infant existence, and to specify, as briefly and clearly as may be, the treatment demanded by Nature and common sense for the preservation of the frail little lives that are perishing by millions for want of it."

maps are compiled from the returns of the Signal-Service Office, and are designed to show, graphically, by an equable standard and on impartial authority, chiefly, the average amount of cloudiness and precipitation at every place in the United States, for the year and for each season. In addition to this, they give the isothermal lines, the directions of prevailing winds, and of winds that usually and those that do not usually bring rain or snow, elevation above the sea, location of mineral springs, annual, monthly, and daily ranges of temperature, and other information that can be given graphically, or in a table, relating to the climatology of our country. The maps can be had separately, or, as in the case of the set submitted to us for examination, mounted on opposite sides of the same sheet.

is an attempt to discover the physical law influencing sex in the embryo of man and brute, and its direction to produce male and female offspring at will. The subject is an important one to breeders, and the author thinks he has discovered its law, claiming that the determination of the sex of offspring in all life lies in the separate physical conditions of the two parents. In his book he shows how he has reached his conclusion, brings forward the evidence by which he believes it is sustained, and makes suggestions respecting its practical bearing.

first edition of the "National Dispensatory" was published in 1879. It included descriptions of all crude drugs and chemical and pharmaceutical preparations, officinal in the Pharmacopoeias of the United States and Great Britain, together with the more important medicines of the French Codex and German Pharmacopœia which were, to some extent, prescribed here, or which might serve for comparison with similar articles in the English and American standards; also, of drugs not recognized by any Pharmacopœia, but often kept in the shops