ACADEMY OF NATURAL SCIENCES. 399 



hills, and the level benches, which these beds have produced along their sides, 

 by irregularities of wear, impart a peculiar aspect to the scenery. 



Professor Silliman read the following : 

 On the Occurrence of Glauberite at Borax Lake, California. 



BY B. SILLIMAN. 



Glauberite, a species not before recognised as occurring in North America 

 occurs at Borax Lake, where it has lately been obtained in blue clay, brought 

 up from a depth of forty feet by an artesian boring. No other crystallized, 

 species was detected in the masses of clay examined. 



Glauberite is a sulphate of lime and soda, half an atom of each base in com- 

 bination with an atom of sulphuric acid. It is usually associated with rock 

 salt, as at Villa Rubia, in New Castile, and also at Ausee, in Bavaria, and in 

 the salt mines of Vic, in France. In the Atacama desert in Peru, it is asso- 

 ciated with a fibrous borate of lime called Hagesine. Mr. Stretch, the State 

 Mineralogist of Nevada, in his catalogue of minerals found in that State, men- 

 tions borate of lime (Hagesine) as occurring in globular masses and in layers 

 from two to five inches thick, alternating with layers of salt in a salt marsh 

 in the Columbus mining District, Esmeralda County. It is quite possible that 

 a careful scrutiny would detect glauberite also in this association so analagous 

 to that of Atacama. 



Reference was also made to the occurrence of the species laghassite detected 

 by Prof. S. in 1864, at the little Salt Lake near Rag Town in Nevada, as illus- 

 trating in an interesting manner, the chemistry of these bodies of saline water 

 The latter species is a hydrous, carbonate of lime and sodium, while glauberite 

 is a sulphate of the same bases. Both salts undoubtedly result from the reac- 

 tion of the respective elements pre-existing in solution in the saline waters. 



The crystals of glauberite from Borax Lake occur in very thin flattened tables, 

 derived apparently from the great extension of the faces O of the Monactinic 

 prism. 



Mr Bloomer read the following : 



On the Scientific Name of the "Big Trees." 



BY H. G. BLOOMER, CURATOR OF BOTANY. 



Early in 1853, specimens of the " Big Trees' 5 were presented to this Acad- 

 emy ; Dr. Kellogg and other botanists, members of the Academy, at once pro- 

 nounced them to belong to the genus Taxodium, to which the common " Red- 

 wood " of California was referred at that time. Endlicher's work upon the 

 Coniferse, in which the genus Sequoia (named after an Indian Chief) was insti- 

 tuted, had not at that time reached us. Our California Redwood, Taxodium 



