Botany. 477 



brown color and greasy luster. The hardness is 5*5 and the spe- 

 cific gravity is 3*413. The mean of two analyses of material 

 dried at 100°, gave : 



Si0 2 Y 2 3 Er 2 3 Ce 2 3 CaO MgO FeO Na 2 C0 2 H 2 



34-63 37-61 tr. 1595 0-03 0-26 0-40 5'90 5-26=100-10 



The composition of the mineral is so remarkable that it is to be 

 hoped that more specimens for examination may be found. A. E. 

 ISTordenskiold in Geol. For. Forh., Stockholm, viii, 143, 1886. 



Hydrogiobertite is a hydrous carbonate of magnesium occur- 

 ring in spherical forms which are compact and of a light gray 

 color. Imbedded in them are minute crystals of magnetite. The 

 specific gravity is 2*149-2'174. An analysis yielded : 



MgO C0 2 H 2 



44-91 25-16 29-93 = 100 



which corresponds closely with the formula 2MgO, C0 2 , 3H 2 0. 

 The mineral was found in an isolated mass of augite porphyry 

 from the neighborhood of Pollena. — E. Scacchi in Rend. R. Accad. 

 JSfapoli, December, 1885. 



8. 1 he various forms in which gold occurs in nature. — Profes- 

 sor W. P. Blake has contributed to the Report of the Director 

 of the IT. S. Mint for 1884 an article of twenty-five pages on the 

 forms of native gold. He summarizes the observations of the 

 various authors, giving a series of figures of the commonly occur- 

 ring forms of crystals ; to these he adds some original observa- 

 tions upon the peculiar distorted and cavernous crystals from 

 California, which are fully illustrated. The remarks on the 

 occurrence of gold in different localities, upon gold nuggets, and 

 other points will also be read with interest. 



III. Botany. 



1. Handbook of Plant Dissection ; by T. C. Arthur, M.Sc, 

 Charles N. Barnes, M.A., and John M. Coulter, Ph.D., edi- 

 tors of the Botanical Gazette. New York : Henry Holt & Co. 

 1886 ; pp. 256, 12mo. — These three active botanists and teachers, 

 mostly Professors in Indiana colleges, where botany is much in 

 advance, have conspired to furnish their students and all others 

 who may be advantaged thereby with a succinct manual for lab- 

 oratory use in elementary vegetable biology. Their work appears 

 to be a very painstaking and faithful guide and helper to a kind 

 of botanical work which is now popular, and for which great and 

 various facilities — instrumental and other — have recently been 

 supplied, by which such investigation is rendered practicable and 

 profitable. So that now — thanks to the increase of good teachers, 

 and of such helps as books of this sort — histology and organ- 

 ogeny are becoming a part even of elementary botanical educa- 

 tion. The results are hopeful. For intending medical students, 

 who cannot pursue botany far, and who early need this special 



