ACKNOWLEDGMENTS TO CORRESPONDENTS, FRIENDS 

 AND STRANGERS. 



Remarks.— This method of acknowledgment has been adopt- 

 ed, because it is not always practicable to write letters, where 

 they might be reasonably expected ; and still more difficult is it 

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

 lets, fee, which are kindly presented, even in cases, where such no- 

 tices, critical or commendatory, would be appropriate ; for it is often 

 equally impossible to command the time requisite to frame them, or 

 even to read the works ; still, judicious remarks, from other hands, 

 would usually find both acceptance and insertion. 



In public, it is rarely proper to advert to personal concerns ; to 

 excuse, for instance, any apparent neglect of courtesy, by pleading 

 the unintermitting pressure of labor, and the numerous calls of our 

 fellow-men for information, advice, or assistance, in lines of duty, 

 with which they presume us to be acquainted. 



The apology, imphed in this remark, is drawn from us, that we may 

 not seem inattentive to the civilities of many respectable persons, au- 

 thors, editors, publishers, and others, both at home and abroad. It 

 is still our endeavor to reply to all letters which appear to require an 

 answer; although, as a substitute, many acknowledgments are made 

 in these pages, which may sometimes be, in part, retrospective. — 

 Eds. 



SCIENCE. FOREIGN. 



Address at the anniversary meeting of the Royal Geographical 

 Society, May 24, 1841 ; by George B. Greenough, President. For- 

 warded by J. Vaughan. 



Fourth Report on the Geological Survey of the province of New 

 Brunswick ; by Abraham Gesner, F. G. S. St. John, 1842. pp. 

 101. From the Author. 



An account of experiments made with the view of ascertainino- 

 the possibility of obtaining a spark before the circuit of the voltaic 

 battery is completed ; by John P. Gassiot, Esq. From the Philo- 

 sophical Transactions, Part 1st, 1840. London. 4to. pamphlet, 

 pp. 10. From the Author. Received April 16, 1842. 



Bulletin de I'Academie Royale des Sciences et Belles Lettres de 

 Bruxelles, annee 1841. Tome Huitieme, Ire partie. 8vo. pp. 

 503. Bruxelles, 1841. From M. Quetelet. 



