190 Bibliography. 



enlarged philosophical views, with respect to the extraordinary creatures 

 which Dr. Mantell has rescued from the -darkness of ages, and restored 

 to their proper position in the creation. Those who would know the full 

 bearing of the facts, especially those regarding the extinct saurians, 

 must peruse the larger works of the author, his Tilgate Forest, his 

 Geology of the Southeast of England, and his Wonders of Geology. 

 We are truly sorry to have him terminate his memoir on the Iguanodon, 

 by adopting the words of Cuvier : " Je termine ici mes travaux, et je 

 laisse a mes successeurs a cultiver un champ que je n'ai fait qu'ouvrir, 

 et qui bien certainement leur donnera encore des moissons plus riches 

 que toutes celles que j'ai pu recueiller."* 



7. Treatise on Algebra ; by Thomas Sherwin, Principal of the 

 English High School, Boston. (Communicated.) — Among the publi- 

 cations designed for the instruction of youth, which are daily issuing 

 from the press, our attention has been recently directed to the elemen- 

 tary work named above. We think this work cannot fail to find its 

 way to the favor of all who give it a careful perusal. The author, in 

 his preface, modestly acknowledges his indebtedness to several prece- 

 ding works of the kind, particularly that of Colburn, the favorite of the 

 Massachusetts school-room, which, however, it surpasses in the num- 

 ber of examples for px-actice. These are so numerous, and so well 

 chosen, that we are confident that a careful and correct solution of 

 them will secure to the student something beyond a merely superficial 

 knowledge of the subject. In the earlier part of the work, we were 

 particularly pleased with several sections. One on the subtraction of 

 negative quantities, which we remember in our school days was consid- 

 ered a most intricate subject ; another on the "greatest common divi- 

 sor," the reasons of which are seen in the school arithmetics as through 

 a glass darkly ; and a third on generalization, then held in almost rev- 

 erential awe. Of the more advanced sections, we were pleased with 

 those on negative exponents, and the unusually numerous examples in 

 this department, will be found very useful. We were interested with 

 the section on inequalities, and with that on ratios, of which Colburn 

 and some other writers say nothing. The section on logarithms, with- 

 out entering on the tedious calculations necessary in the actual forma- 

 tion of tables, gives a very good idea of the manner in which they may 

 be constructed, and forms a happy introduction for those who desire to 

 become better acquainted with the more abstract treatises. The mis- 

 cellaneous examples at the last of the work, serve as a recapitulation of 

 the whole, and a test by which the learner may judge of the degree of 



* Recherches sur les Ossemens Fossiles, torn, v, p. 526. 



