8 DESERT BOTANICAL LABORATORY 



elly and probably washed nearly free from alkali; (2) the mesquite 

 area already described; (3) the Atriplex area also already described, 

 and (4) the White Sands. 



The Tularosa desert as traversed by the railroad from Alamogordo 

 south to El Paso has a red and apparently mellow soil, the most char- 

 acteristic plant of which is Yucca radiosa^ sometimes associated over 

 large areas with grass, but often associated with low mesquites, the 

 latter in some spots gathering large hummocks of earth from drifting 

 dust, out of which the twigs of the mesquites project. A large Ephe- 

 dra is also a frequent associate of the mesquite and yucca. The rail- 

 road traverses only a little of the creosote bush foot slopes of the moun- 

 tains. 



Analyses of Sands. — The following report on the gypsum sand from 

 the White Sands of the Tularosa desert and on sand from the Chihua- 

 huan desert has been received from Dr. William J. Gies : 



Gentlemen : I present herewith the results of my chemical analyses of the two 

 samples of sand expressed by you to me from Tucson, Arizona, on February 16 

 and received by me on February 24 : 



SAMPLE I. locality: TULAROSA DESERT, NEW MEXICO.^ 



General Descrij)tio7i. — Color white to delicate cream, with occasional very 

 minute black particles. There were also a few reddish and yellowish-red grains. 

 Now and then red specks could be detected in the white grains. Glassy grains 

 of silica were present. Nearly all the grains were very small, about the size of 

 those in ordinary sea sand. A few larger masses were made up of many of the 

 small grains cemented or fused together. These masses were more cream 

 colored "than the small grains, some contained a dark nucleus. They varied in 

 size from such as were only three or four times the bulk of the uniformly 

 small grains to a few which were nearly as large as a pea. No special crystalline 

 qualities were observed in any sample of the sand. The grains were angular, 

 or rounded by erosion. Fragments of elytra of beetles were detected and oc- 

 casional pieces of hair, and small splinters, were also seen. 



Before subjecting the sand to analysis it was passed through a copper sieve 

 the meshes of which were just large enough to permit the passage of the typical 

 and uniformly-sized grains. Only a few grams of material consisting of the 

 larger fused particles, elytra of beetles, hair, etc., was separated in this way from 

 four kilos of the sand as received. All of this material was regarded as extraneous 

 matter, and only the main bulk of the sand was analyzed quantitatively. 



Qualitative Data. — The sand dissolved readily in water and in dilute acids, 

 leaving only a slight residue of silicious matter. The black particles in the sand 

 seemed to be entirely insoluble in these media. The aqueous solution was neu- 

 tral to litmus. The hydrochloric acid solution was slightly yellowish in color, 

 due doubtless to the presence of iron. On diluting the hot concentrated sul- 

 phuric acid solution, crystals of calcium sulphate quickly separated. On ignit- 

 ing the sand it immediately blanched, and abundance of water was evolved, but 

 the sand did not fuse, even in platinum, over a blowpipe. Extraction of the 



