122 » Scientific Intelligence. 
The characteristic differences heretofore insisted on in color, hardness, 
specific gravity, é&c. being well accounted for by the isomorphous. re- 
placement of alumina and peroxide of iron, and protoxide of iron and 
zinc. This opinion is confirmed by the following comparison of com- 
positions, according to the analysis of automolite by Eckrsrre and 
Asicu. 
Dysluite, Ox. Ratio. Automolite. Ox. Ratio. 
Alumina, 30°49 14:23 20-51—3 Alumina, 57:09 25°37=3 
Perox. Iron, 30-00 6-00 
Mace Tron, 11-938 2°65 Magnesia, 2:°22> 7:42=1 
x.Mang.7°60 1 6s | 758=1  Protox. Iron, 4°55 
Oxide Zinc, 16°80 3:20) THomson. Asicu and EcKkesereé. 
_ To confirm this probable view, a new analysis of dysluite is requi- 
red, to show the iron to be protoxide, as Dr. Tuomson, (the only 
chemist who has analyzed this mineral,) states it to be peroxide. 
47. Acadiolite of Nova Scotia, (Chabasite.)—Mr. A. A. Hayes, of 
Roxbury Laboratory, analyzed this mineral for Mr. AtcEr’s edition of 
Puituirs’ Mineralogy. As the analysis has not before been Roblin 
in this Journal, we annex it. 
Il. 
Silica, . 52-02 52°20 
Alumina, - 17:88 18-27 
Lime, - 4°24 6°58 
Potash - 3°03 
Soda,» | 40¢ } wee 
Water, - 18-30—99.54 Hares. 20-52—99-69 Haves. 
These results agree closely with those obtained by Horrmann, and 
prove the identity of this mineral with chabasite, although RaMMgLs- 
BERG has given a somewhat different formula for the two. 
48. Washingtonite of Shepard.—This mineral was analyzed by Mr. 
J. L. Kenpatt, under the direction of Dr. C. T. Jackson, (also for Mr. 
Aucer’s book,) and gave the ANS result : 
Ratio of Ox. 
Titanic acid, . “ - 25°28 Sit 
Peroxide of iron, © - : - 51-84 2 
Protoxide of iron, - - - 22.86—-99:98 1 
The identity of this mineral with an Ilmenite from Arendal, analyzed 
by Mosannsr, cannot be questioned, thus : 
} ; Ratio of Ox. 
Ilmenite of Arendal by Mosanprr,—Titanic acid, 24:19 1 sis: 
Perox. iron, 53°01 2 
Protox. iron, 19-91 } 12 
Mag. and lime, 1-01 
Mexican Fossils, (citéd from Ann. Mag. Nat. Hist. xvi, 1845, p- 
1 a letter to Prof. Bronn, M. Cravssen states that he has again 
