ACKNOWLEDGMENTS TO CORRESPONDENTS, FRIENDS 
“pee 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, &c., 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, implied 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. 
Account of the Museum of Economic Geology and Mining Re- 
cords Office established by government in the department of her 
Majesty’s Commissioners of Woods and Forests, under the direc- 
tion of Sir Henry De La Beche, F. R.S., F.G.5.; by T. Sop- 
with, F. G.$. London, 1843. From R. Phillips. 
On the theory and construction of a Serismour, or instrument for 
measuring earthquake shocks, and other concussions; by James D. 
Forbes, Esq., F. R. S., &c. From the Transactions of the Royal 
Soc. of Edinburgh, Vol. XV, part 1, 1841. From the author. 
On a remarkable structure observed by the author in the ice of 
glaciers; by J. D. Forbes, Esq., with a plate. Read before the 
Royal Society of Edinburgh, 1841. From the author. 
Observations on the Aurora Borealis from Sept. 1834, to Sept. 
1839; by Robert Snow, Esg. London, 1842. From the author. 
