Scheerer on Isomorphism. 387 
_ It was to be expected that this peculiar species of isomorphism 
would not manifest itself by one insulated fact, but that, as far 
at least as the mineral kingdom is concerned, it must play a more 
or less important and general part, and that further proofs of the 
justice of my views would in consequence be drawn from the 
composition of other hydrous minerals. My attention was in the 
firs directed to an examination of one of the most common 
hydrous silicates of magnesia, serpentine. 
. Serpentines.—The analysis of serpentines from different lo- 
calities has led to results which, as shown by the following table, 
differ very materially. 
- 
Serpentine from Si Mg Ca | Fe | Mn} H Other constituents. 
1. Snarum, according to Hartwall, [42-97/41-66, . |2-23, . |12-270°87 Al 
2. Sala, “ Lychnell, |42-16'42-26 . |1-98| . |12:33)1°03 bitumen and C 
3. Gullsjé, Mosander, |42'3444:20| . | . | . (1238089 C 
4. Snarum, “ my analysis,*}40°71/41-48 . [2°43 
5. New York, “ ck, 41-00/41-262'39 1-85 
6. Fahlun, se Jordan, |40°32/41-76) . (3°33 
7. Hoboken, Lynchnell, |41-67)/41-25| . |1-48) . 
8. Fahlun, “ Marchand, |40°52/42:05| . |3-01 
9. Philippstadt, Stromeyer, |41:66/37-16, . /4-05 
10. 2 “ John, 42-50|38-63}025 1°35 
11. Massachusetts, “ | Shepard, [40-08)41-40| . |2-70| . 
12. Bare Hills, « Vanuxem, |42°69/40-00) . |1-16) ». 
13. New York, “ Beck, 40-50'38-00' . | . 
tines as Al Si, we obtain the following proportions : 
Si R Si R 
1, 21:91 : 20-27 8. 21-07 : 20°95 
2. 21:90 : 20-46 9. 21-64 : 20-12 
3. 21:99 : 20-78 10. 21-61 : 19-96 
A. 20°03 : 20:34 11, 20°82 : 21:28 
6, 21:30 ; 21°09 12. 22°18 : 20°52 
6. 20-93 : 20-95 13; 21°04 : 20-93 
7. 21°65 : 20°39 ; 
Oras a mean of these thirteen ratios, 21°39 : 20°62; or in other 
Words, 100 : 96-4, 
DE cas ge 
* In this analysi | ion of the Ail from the Mg, was care- 
fally es a ee the complete separation o g 
Srconp Series, Vol. V, No. 15.—May, 1848. - 50 
