XVIII. On some Stereoscopic Experiments ; by Professor O. N. 

 Rood, of Troy, N. Y., ....... 



XIX. Tenth Supplement to Dana's Mineralogy ; by Geohge J. 

 Brush, Professor of Metallurgy in Yale College, 



XX. On Pliosphaiic Guano Islands of the Pacific Ocean ; by J. D. 



Hagu 

 XXL Cont 



ributions 



from the Sheffield Laborato 



ry of Y 



ale Col. 



lege.- 



-III. On 



Amblygonit 



e from Hebron 



in Ma 



ine; by 



Geori 



SE J. Br 



USH,- 









XXII. On 



a constar 



it Aspirator i 



md Blower ; by 



M. Cae 



EY Lea, 



Pliilac 



lelphia, 











XXIIl. En 





n of the Plai 



nts of Dr. Parry 



's ColU 



action in 



the Rocky Mo 



unlains, (con 



linued from vol. 



x.xxiii, 



p. 411); 



by A. 



Gray: 



with Supplen 



lents by G. Eng 



iELWANI 



V and A. 



XXIV. Abstract of a discussion of the Horizontal Component of 

 the Magnetic Force, from observations made at the Girard 

 College Observatory, Philadelphia, in the years 1840-'41- 

 '42-'43-'44-'45 ; by A. D. Bache, LL.D., F.R.S, etc, - 



Utm Iry-On Stir 

 -Dja« Oder In /ec 





