the splendid plates in the former work, have been reduced and given as wood cuts; and I flatter myself that the history of Glaciers, and its application to what has been called Diluvial Action, given in Section VI., will be regarded as a new and important chapter in Geology: throwing much light upon some of the most difficult parts of the Science. These and some other additions have enlarged the present edition by about a dozen wood cuts, and seventeen pages. To enforce still more strongly the remarks of Dr. Smith, in the unsolicited Introductory Notice of this work which follows, respecting the importance of an acquaintance with Geology to the minister and the missionary, I will quote a few sentences from the letters of two esteemed missionary friends, now in active service in distant lands. Rev. Justin Perkins, American Missionary in Ooromiah in Persia, under date of Oct. 1, 1839, thus writes. "Did not my missionary work press upon me so constantly, and with such mountain weight, I should feel strongly tempted to study geology, (of which I know very little,) so wonderfully interesting, in a geological point of view, does the face of Persia appear to me. Indeed, I often feel that this interesting and important science has peculiar claims on American Missionaries. Visiting, as they do, all portions of the world, they enjoy opportunities of contributing to it, with almost no sacrifice of time or effort, which are possessed by no other class of American citizens. I know not that I can better atone for my own deficiency in this respect, than by requesting you, in my behalf, to urge upon the missionary students in College, the high importance of their obtaining a good practical knowledge of geology and mineralogy, while attending your lectures, as they would enhance their usefulness, in future life. It is the combined light of ALL TRUTH, scientific, as well as religious, which is to render so perfect and glorious the splendor of millenial day !" To show that geology sometimes becomes to the missionary a matter of practical importance, I will quote a few sentences from another American Missionary, who has charge of a Seminary for youth at Beyroot in Syria. Rev. Story Hebard writes thus from the Island of Cyprus, on the 23d of April, 1840. "Our Seminary at Beyroot, is in a flourishing condition. I wish very much to interest my pupils in the study of the Natural Sciences. They are well acquainted with our language, and are now sufficiently advanced to study some of these with advantage. Next fall, or winter, I wish to give them a course of lectures on mineralogy and geology." Amherst College, Mass. INTRODUCTORY NOTICE. BY DR. J. PYE SMITH, OF LONDON. In a manner unexpected and remarkable, the opportunity has been presented to me of bearing a public testimony to the value of Dr. Hitchcock's volume, ELEMENTARY GEOLOGY. This is gratifying, not only because I feel it an honor to myself, but much more as it excites the hope that, by this recommendation, theological students, many of my younger brethren in the evangelical ministry, and serious christians in general, who feel the duty of seeking the cultivation of their own minds, may be induced to study this book. For them it is peculiarly adapted, as it presents a comprehensive digest of geological facts and the theoretical truths deduced from them, disposed in a method admirably perspicuous, so that inquiring persons may, without any discouraging labor, and by employing the diligence which will bring its own reward, acquire such a knowledge of this science as cannot fail of being eminently beneficial. It is no exaggeration to affirm that Geology has close relations to every branch of Natural History and to all the physical sciences, so that no district of that vast domain can be cultivated without awakening trains of thought leading to geological questions; and, conversely, the prosecution of knowledge in this department, cannot fail to excite the desire and to disclose the methods of making valuable acquisitions to the benefit of human life. In our day, through every degree of extensiveness, from the perambulation of a parish to the exploring of an empire, TRAVELLING has become a "universal passion," and action too. Within a very few years, the interior of every continent of the earth has been surveyed with an intelligence and accuracy beyond all ex ample. Who can reflect, for instance, upon the activity now so vigorously put forth, for introducing European civilization, the arts of peace, the enjoyment of security, and the influence of the most benign religion, into the long sealed territories of Central Asia, and not be filled with astonishment and delightful anticipation? Similar labours are in progress upon points and in directions innumerable, reaching to the heart of all the other vast regions of the globe: and the men to whom we owe so much and from whom so much more is justly expected, are geologists, as well as transcendent naturalists in the other departments. Whoever would run the same career must possess the same qualifications. Even upon the smallest scale of provincial travelling for health, usiness, or beneficence, acquaintance with natural objects opens a thousand means of enjoyment and usefulness. The spirit of these reflections bears a peculiar application to the ministers of the gospel. To the pastors of rural congregations, no means of recreating and preserving health are comparable to these and their allied pursuits; and thus, also, in many temporal respects, they may become benefactors to their neighbours. In large towns the establishment of libraries, lyceums, botanic gardens, and scientific associations, is rapidly diffusing a taste for these kinds of knowledge. It would be a perilous state for the interests of religion, that "precious jewel" whose essential characters are "wisdom, knowledge and joy," if its professional teachers should be, in this respect, inferior to the young and inquiring members of their congregations. For those excellent men who give their lives to the noblest of labours, a work which would honour angels, "preaching among the heathen the unsearchable riches of Christ;" a competent acquaintance with natural objects, is of signal importance, for both safety and usefulness. They should be able to distinguish mineral and vegetable products, so as to guard against the pernicious and determine the salubrious; and very often geological knowledge will INTRODUCTORY NOTICE. xi be found of the first utility in fixing upon the best localities for missionary stations; nor can they be insensible to the benefits of which they may be the agents, by communicating discoveries to Europe or the United States of America. To answer these purposes, and especially in the hands of the intelligent and studious ministers of CHRIST, this work of Professor Hitchcock appears to me especially suited. Though I flatter myself that I have studied with advantage the best English treatises on Geology, and find ever new improvement and pleasure from them; and have also paid some attention to French and German books of this class; I think it no disparagement to them to profess my conviction that, with the views just mentioned, this is the book which I long to see brought into extensive use. The plan on which it is composed, is different from that of any other, so far as I know, in such a manner and to such a degree, that it is not an opponent or rival to any of them. Yet, in this arrangement of the matter, there is no affectation: all is plain, consecutive and luminous. It is more comprehensive with regard to the various relations and aspects of the science, than any one book with which I am acquainted; and yet, though within so moderate limits, it does not disappoint by unsatisfactory brevity or evasive generalities. Such is the impression made upon me by the first edition of the "Elementary Geology,” and I cannot entertain a doubt but that the ample knowledge and untiring industry of the author will confer every practicable improvement upon his proposed new edition. I received a deep conviction of the Professor's extraordinary merits, from his "Report" upon the Geology, Botany and Natural History generally of the Province of Massachusetts, made by the command of the state government; a large volume, published in 1833, and the second edition in 1835: and from his papers in the "American Biblical Repository," which were of great service to me in composing a book on "The Relation between the Holy Scriptures and some parts of Geological Science." But I did not till recently know that he was a "faithful brother and fellow-labourer in the gospel of Christ." An edifying manifestation of this, it has been my privilege to receive, in Dr. Hitchcock's "Essay and Sermon on the lessons taught by sickness," |