variable proportions; among them marsh-gas (CH₄) and hydrogen are usually most abundant. Natural gas is widely distributed. It is extensively utilized in Indiana, Pennsylvania, Ohio, West Virginia, New York and California; to a limited but still important extent in Kansas and Kentucky; and to a slight extent in Utah, Colorado, Illinois, Missouri and Texas. The flow of gas from a well usually is of short duration. It may last for a few months or even years, but not indefinitely. The popular notion that the withdrawal of gas from beneath the surface leads to earthquakes is wholly without foundation. The gas occurs in the pores of rock, and its escape does not make the rock less firm or substantial. Gas occurs in rock formations of various ages. Some of it comes from rocks as old as the ordovician (see Geology), and some of it from formations as young as the tertiary or even pleistocene. Natural gas and petroleum are probably associated in origin, as they often are in their distribution.
Nat′uraliza′tion, the process by which a person born in another country becomes possessed of the privileges and is placed under the obligations of a citizen of the country in which he resides. It involves the renunciation of allegiance to one country and the adoption of the other. It was not until 1870 that Great Britain recognized such a renunciation by any of its subjects, and before that time would charge with treason any person having so done, if he bore arms against Britain; but in that year a treaty was made by which Englishmen who had been naturalized in this country, were treated as citizens of the United States and vice versa. The conditions upon which one can become naturalized differ materially in various countries. In the United States a foreigner must make oath of his intention to become a citizen. If at this time he has resided three years in the United States, he receives what are known as his “first papers.” Then, after the lapse of two years, upon a sworn substantiation of his good morals, a five years' residence and a renunciation of all allegiance to any and all foreign monarchs or potentates and all titles of nobility, before any one of the superior, district or circuit courts, he becomes a citizen of the United States. In Great Britain five years' residence or service under the crown entitles a foreigner to a certificate of naturalization, procurable from one of the principal secretaries of state. The British colonies make their own rules for becoming a citizen, applicable, however, only to the colony in which they are made. In France a foreigner, after having obtained permission to reside, may receive a certificate of declaration of intention after three years' residence, and by the French naturalization act of 1889 may become naturalized after ten years residence without any preliminaries. In Germany an applicant must show that the laws of his country allow him to renounce it, that he is residing in Germany, leading a respectable life, and has a means of livelihood; then the higher administrative power issues his papers. In all countries a married woman is considered as subject to the country in which her husband is naturalized, and a father's naturalization carries with it that of his minor children. See Nationality by Chief-Justice Cockburn.
Na′ture-Study. The environments of the child constantly stimulate sense perception and provoke inquiry. They are always arousing him to see, hear, smell, taste and touch. The satisfaction he gets in exercising his senses begets increasing desire to their further exercise, and his ability to discriminate grows rapidly every day. Curiosity and wonder spur him to find out what he can about everything he meets. These experiences are his mental food as well as the means of his physical development. Parents usually pay too little regard to mental culture in the first five years of the child's life, little realizing its relation to the after-life, though his eagerness to know usually accumulates a great fund of child knowledge and even child skill before he enters school. These years powerfully affect his life-long habits of investigation, thinking, talking, language and acting.
On entering school he has already made considerable progress in getting acquainted with the animate and inanimate objects about him. He is usually bubbling over with interest in everything he meets, particularly with those things that give sense pleasure and strike him as strange and novel. His knowledge is already of things in nature as well as of things in the household and about his father's work. This knowledge furnishes a fine starting-point for his school work and suggests the wisdom of continuing it on the very lines so well calculated to maintain and enlarge his interests and encourage him to study. Nature study, then, may rightly engross a large part of the course of study for the lower grades. It serves to introduce the elementary work in the other subjects usually included in the higher grades, and thus provides for that gradual transition to their more abstract phases and their more complex problems which is demanded by all scientific method. The teacher should so plan the nature work, that it not only extends the child's range of experiences but anticipates in a logical way the deeper and broader inquiries which he is to make later.
While there should always be method and system on the side of the teacher, there should always be relative simplicity and variety on the side of the child. The
