Many causes are combining to give great importance to the States of Central America. Their own fertility and natural advantages, the commerce of the Pacific, and the gold of California, unite to attract the earnest attention of enterprising men and politicians towards them. At the present moment, the appearance of this full and able account of Nicaragua is peculiarly well-timed. The writer of it describes himself as "late _chargé d'affaires_ of the United States to the Republics of Central America." His official position has evidently enabled him to get at much information that would otherwise have been inaccessible. His name is well and favorably known to ethnologists and antiquarians by his researches into the history of the aboriginal monuments of the United States, and by his very curious, though somewhat fanciful, essay on "The Serpent Symbol, and the Worship of the Reciprocal Principles of Nature in America." The bias and extent of his studies make him a very competent person to investigate the antiquities of Nicaragua. The chapters devoted to this subject in the work before us are full of interest, and highly to be valued for the abundance of fresh observations they contain. Like many American archæologists and historians, Mr. Squier is inclined to over-estimate the peculiarities and antiquity of the aborigines of the New World. If we understand rightly, he claims for them an independent origin. His ethnology is of the romantic school, and rather loose. His imagination gets the better of his reasoning, and his "organ of wonder," to speak in the manner of phrenologists, is over-developed. His habits of mind and training do not seem to be such as to qualify him for strict scientific research. He is more of the _littérateur_ than the philosopher. His writings are, in consequence, very amusing, but require to be dealt with cautiously. The facts must be winnowed from the fancies with which they are mingled, if we wish to use them for scientific purposes.