Acknowledgments to Friends and Correspondents. 



REMARKS. 



This method has been adopted, because it is not always possible 

 for me to write letters of acknowledgment, even, in cases where they 

 might be reasonably expected ; and still more impracticable is it for 

 me to prepare and insert in this Journal, notices of all the books and 

 painphlets, which are kindly sent to me by their authors, editors or 

 publishers. 



In many cases, such notices would be appropriate, and well de- 

 served ; but it is often equally beyond my power to frame them, or 

 even to read the works ; although, judicious notices from other 

 hands, would usually find both acceptance and insertion. 



It is rarely proper to publish personal concerns, or to excuse any 

 apparent neglect of courtesy, by pleading the unintermilting pressure 

 of multiform duties, and the fortuitous calls of our fellow-men for in- 

 formation, advice, or assistance, in lines of duty, with which they 

 presume us to be acquainted. 



This apology is drawn from me, that I may not appear inattentive 

 to the civilities of many respected persons, both at home and abroad. 

 It is my endeavor to reply to all letters which appear to require an 

 answer : many other acknowledgments are made in these pages, 

 which may sometimes be, as now, in part, retrospective. 



Foreign and Retrospective. 



Received — From M. Alex. Brongniart : 



Essai sur La Geographic Mineralogique des Environs de Paris, 

 &LC. ; par G. Cuvier and Alex. Brongniart. Ed. 1811, quarto, with 

 numerous plates. Do. 1822, much enlarged and improved. 



Essai sur les Orbicules Silicieux, 1831, much enlarged. 



Hisloire Naturelle de I'Eau, he. 1819. 



Notice sur les Breches osseuses et les Minerals de fer pisiforme 

 de meme position geognostique. 1828. 



Notice sur des Blocs de Roches, des Terrains de Transport ers 

 Suede. 1828. 



Sur le Gisement, he. des Ophiolites, Euphotides, Jaspes, &c. 

 dans quelques Parties des Appennins. 1821. 



Macigno. 



Memoire sur une nouvelle espece de Mineral de la classe des sels, 

 nommee Glauberite. 1808. 



Notice sur la Magnesite du Bassin de Paris, &c. 1822. 



De L'Arkose, Caracteres Mineralogiques, et Histoire Geognos- 

 tique, &,c. 1826. 



Sur les Caracteres Zoologiques des Formations, &.c. 3 copies. 

 1821. 



Lettre a M. G. Cuvier et Brongniart sur un terrain d' eau 

 douce, &;c. 1821. 



Observations Additionelles a la Notice sur les Minerals de Fer 

 Pisiforme, he. 1829. 



Lettre a M. Alex- Brongniart, &c, par M= Leopold dc Buch, 



