140 REPORT ON NATIONAL MUSEUM, 1885. 



est as showing the character of the rock in these little-explored regions, 

 but from the fact that both parties supposed they had found the source 

 of the so-called Alaskan jade, and had included rough samples thereof 

 in their collections. A careful examination of the material by myself, 

 however, showed it to consist almost entirelj^ of a compact, fine-grained, 

 greenish quartzite and serpentine, the latter in both the ordinary mass- 

 ive form and in the thinbladed variety, picrolite. Not a i^article of 

 true "jade" (pectolite, according to Clarke's analysis) was contained in 

 either collection. Inasmuch as the reports in the various scientific 

 papers had been to the effect that the source of the jade had actually 

 been discovered, proof to the contrary seemed of sufficient importance 

 to call for a note on the subject, which was therefore published in 

 "Science" for March 13, 1885. 



Mr. I. 0. Eussell, of the U. S. Geological Survey, has further added 

 valuable material to our already extensive collection of the calcareous 

 tufas from Lake Lahontan, Nevada. Inasmuch as these have been the 

 subject of considerable study by Mr. Eussell from a geological stand- 

 point, and by Mr. E. S. Dana* from a mineralogical standpoint, the ma- 

 terial is now of particular value. 



ROUTINE "WORK OF THE TEAR. 



The beginning of the calendar year found the affairs of the depart- 

 ment in a quiescent though somewhat confused state, owing to the fact 

 that since the preceding July the entire energies of the working force 

 had been devoted to the preparation of the exhibits designed for the 

 New Orleans Exposition, and the regular work of the Museum had con- 

 sequently fallen behind. This work was completed late in December 

 and the extra force that had been employed then discharged. January 

 5, under instructions from the Assistant Director, I left Washington for 

 New Orleans, returning the 17tli following, the intervening time having 

 been occupied in arranging in their proper cases, in the exhibition 

 building, the various exhibits prepared as stated above. 



These exhibits consisted of (1) a collection of 358 specimens of build- 

 ing and ornamental stones in the form of 4-inch cubes, (2) a collection 

 of some 12 specimens foreign and native marbles in the form of pol- 

 ished slabs, (3) a collection of 150 specimens of rock-forming minerals,. 

 (4) a collection called a " structural series " intended to represent all 

 the more common forms of rock-structure and texture, (5) a collection 

 of 198 specimens of rocks illustrating the geology and lithology of the 

 Comstock Lode and Washoe District, Nevada, and (G) a lithological 

 collection comprising 500 specimens of rocks of various kinds and from 

 many sources, both native and foreign ; this last, together with collec- 

 tions Nos. 3 and 4, forming a part of the regular educational series of 

 the Museum. As these were all described in my report for 1884, no 

 further reference to them is necessary here. 



■* Bulletin No. 12, TJ. S. Geological Survey. 



