24 GEOLOGY. 



has been mislaid. In view of the difficulty experienced in obtaining this substance in time of 

 war, the subject is well worth the attention of government. 



Many of the earths and rocks were placed in the hands of my lamented friend and classmate, 

 Professor J. W. Baily, for microscopic examination. His state of health did not permit him to 

 go entirely through with the examination. He, however, had made some progress, and I liere 

 give a short and characteristic note from that eminent and beloved gentleman, which gives an 

 interesting summary of the results of his investigations up to that time, 



W. H. E. 



West Poujt, N. Y., April 2, 1856. 



Major W. H. Emoky, Commissimer U. S. M. Boundary Survey. 



Dear Major : This time we have some luck. Three of the specimens last sent prove quite interesting. They are Nos. 

 IS and 19, from cretaceous strata, Leon creek and Leon spring, West Texas, and No. 23, travertin-like crust, from bed of San 

 Pedro 



The specimens Nos. 18 and 1 9 are interesting, as containing a considerable number of fossil Polythalamia, (microscopic cal- 

 careous shells,) and still more so from yielding fine green sand casts of the same minute forms. This fact of the occasional 

 formation of green sand in the cavities of minute shells was discovered by Ehrenberg, and I have verified it in specimens 

 from several American localities. I would be glad to get a good supply of Nos. 18 and 19 for further study. 



The travertin-like crust, No. 23, has an organic basis. When treated with chloro-hydric acid, it leaves a spongy mass, 

 greater than the original volume, and composed of plants belonging to the genera Oscillatoria, Hydrocoleum, &c. There 

 are several of these plants which delight in calcareous waters, and always incrust themselves as in the specimens you have 

 sent. 



With regard to the moss agates, I cannot satisfy myself that the filamentous mosses in them are really of confervoid origin. 

 If they were, it is now impossible to distinguish a single vegetable cell. I incline to the belief that thev are rather concre- 

 tionary deposits of oxide of iron, which may possibly have had organic nuclei to collect upon ; but if so, these last have 

 disappeared. 



The cretaceous earths attached to the Texian fossils will be well wor& further study, and any which have specks of green 

 sand in them will be particularly interesting. 



Yours, very truly, 



J. W. BAILEY. 



New York, 13 Mercer street, January 31, 1854. 

 Three samples forwarded for analysis : 



No. 1. Silver ore from San Pedro mine. 

 No. 2. Ore from copper mines. 

 No. 3. Ore from Leona mines. 

 No. 1. — Argentiferous galena ; partly granular, chiefly fibrous ; specific gravity 603. It contains iron pyrites, dissemi- 

 nated in small cavities. 



The amount of silver was determined by moist analysis. Two grammes of ore were treated with nitric acid ; to the clear 

 solution hydrochloric acid was added — the resulting cloride of silver fused. The lead was determined as carbonate, by adding 

 carlionate of soda to the solution, after separating the silver. Some adhering earthy matters remained undissolved by the 

 nitric acid. 



Analysis yielded in 100 parts : 



Insoluble silicates 4. 50 



Lead 82.20 



Sulphur 12. 79 



Oxide of iron and traces of copper .46 



Silver 03 



Loss - - 02 



100.00 



Indicating a yield of 6J ounces of silver per ton. 



No. 2. Red ccfper ore. — Massive ; specific giavity 5. 10 ; of a deep liver red color in fresh fractures, coated on the outside 

 ■with a crust of green malachite, to the depth of -^ of an inch ; dissolved with slight effervescence in nitric acid ; it fur- 



