252 Scientifie Intelligence. 
ar et sah — of induction, and that M. du Bois Rey- 
in neglecting the induction of the current path 
mo 
sit itself which ‘ants was really the ebb ig agent in actin 
the agreement between theory and pra Ten days later M, 
Helmholtz presented a paper to the Berlin Mkadeinte der Wissen 
schaften which covered the same Simul, as Prof. Weber s yt 
n the 
the path of the current, and depends on the number of vibrations. 
(3.) ‘In certain cases, however, the amplitude of the induced cur- 
rent becomes independe ent of the vibration number n and re the 
tone of the exciting sound is unchanged.” 
II. GroLtoay AND Natura History. 
eports upon the Specimens obtained from borings made in 
sre: betioden the Y Missisa pi River and Lake Borgne, oe zt site 
proposed for un outlet for Flood Waters ; by Prof. Eve EW. 
HILGARD an r: . HopKIns, With a letter of ‘ea heanittal 
from Byt. Maj. Gener al G. K. Warren, Major of Engineers, 
President of the Com mmission. Washing ton, 1878.—This memolr, 
° 
c 
2 to 4) marine sandy beds, exce ane 3 feet of oe! (No. #5 then, 
from 21 to 41 feet in depth, a f io-marine clay, 
bered 8; and, at top, 21 feet of frag weiter bluish Sah clay, 
here numbered A, 
In the borings of 1874 ead to in the above title, ed same 
beds were met with. No. 1 was reached in four of them t the 
depth of 91 to 97 feet, and No 4, below 57 to 72 feet; poh “iste 
found to ‘ibang ee marine shells, while the thin clay bed 
No. 3, appeared to be a fluviatile stratum. No. 4 has a orded 
the shells Malone eburneus, Nassa acuta, Anachis avara, Oliva 
Rie oma Pade: Chione cancellat ‘a, Ch. eribra ae Dosi 
Lucina nratilinentay 1 7 PRTG "Area transvei "sa, Pocket dislo: 
eatus, and other s 
was met with it in four borings near Lake Borgne betw 
the upper levels 25 to 26 feet, and the lower 52 to 56 feat, i in 
