HANDBOOK FOR THE DEPARTMENT OF GEOLOGY 589 



APPENDIX. 



Aside from the collections described above as forming the exhibition 

 series, as illustrative of the mineral aggregates forming any appreciable 

 proportions of the earth's crust, there are in the department, stored 

 away in the table cases, many collections designed primarily for study. 

 These are so arranged as to be accessible to the student on application 

 to the Director of the Museum, and on presentation of proper creden- 

 tials if such be deemed necessary. The collections thus stored are 

 classed under the head of the study series. In preparing and arrang- 

 ing this series it may be well to state that it is made up largely of such 

 materials as have somewhere and at some time been subject to investi- 

 gation. Each specimen, after trimming to a size approximating 3 by 

 4 by 1 inch, has a number painted on it in oil colors, and which refers to 

 a written catalogue in which is given whatever detailed information 

 regarding its source and nature may be in possession of the depart- 

 ment. The specimen is then placed in a pasteboard tray, accompanied 

 by a written label containing the same information as given in the 

 catalogue, and placed in the drawers of the table cases. Material which 

 is designed for the study series is, if of a miscellaneous nature, distribu- 

 ted through the collections in a systematic manner, corresponding to 

 that adopted for the exhibition series. Collections which like those 

 from Leadville and the Eureka district, to be noted later, represent 

 systematic work upon rocks of a definite area, or which have been 

 studied as a group for the elucidation of some particular problem, are 

 kept intact in order to best serve the purposes of the investigator. 

 Characteristic rocks have in some cases been selected from these col- 

 lections for exhibition purposes, but the individuality of the collection 

 is in no case allowed to become destroyed. 



The more important collections in this study series are mentioned 

 below : 



(1.) Systematic study series. — This collection comprises some 3,000 spec- 

 imens miscellaneous rocks from all parts of the globe classified sys- 

 tematically as in the exhibition series. 



(2.) The Leadville collection. — This comprises some 380 eruptive, sedi- 

 mentary and metamorphic rocks and ores as collected and studied 

 by Messrs. S. F. Emmons and C. Whitman Cross, of the U. S. Geo- 

 logical Survey, from the vicinity of Leadville, Colorado. It is a rep- 

 resentative collection of the materials described by the above-named 

 authorities in Monograph xn of the U. S. Geological Survey, J. W. 

 Powell Director, and entitled " Geology and Mining Industries of Lead- 

 ville." A characteristic series of the rocks and ores has been selected 

 out and placed upon exhibition in the section devoted to economic 

 geology (catalogue Nos. 68801-69540, inclusive). 



(3.) The Washoe collections. — These collections represent the work done 

 by G. F. Becker and colleagues in the Washoe district and Coinstock 



