Notice of Quekett’s Treatise on the Microscope. 65 
nitrate of cobalt and heated. In aclosed tube yields water. B. B. 
fuses with great difficulty. Occurs with Picranalcime in the 
Gabbro rosso. 
Humboldtite, (Datholite.)—Monoclinic, and apparently like 
the figures of Levy. Composition :— 
Bi Ga Mg H 
87500 = O'852 0 B5'B41—«s BTDD | 22088. 56290418. 
_ Formula, 2(Ca* 814-862 B)+-Mg H2=Si 38-75, Oa 35:36, B 21-93, H 1°87, 
Mg 209. The mineral of the Seisser Alp gives the same compo- 
sition. Dissolves in the acids, forming a jelly, and oxalate of am- 
monia gives an abundant precipitate, which dried, dissolved in 
alcohol, and inflamed, affords a flame colored green on the borders. 
- B. fuses very easily. Occurs with Schneiderite, in the same 
Manner as at the Seisser Alp, associated with Apophyllite in 
geodes in the Gabbro Rosso. 
Arr. XI.— Notice of A. Quekett’s Practical Treatise on the use 
eae of * 
Tue first edition of Mr. Quekett’s work appeared at a time 
when there Was a general dearth of books on practical micro- 
scopy had made considerable Pee and some work was n 
“i '. Quekett’s work, evidently the result of much practical 
nowledge, was therefore warmly welcomed, and the rapid sale 
both needed and 
Pee appreciated. og 
ny With all its value however, it had, as a general practical work, 
* A Practical Treatisé se of the cope, including the different meth- 
— “¢ mugne cakes best Br pret a ineral structures; by Joun 
, Assistant Conservator of the Museum, and demonstrator of minute anatomy 
+ the Ro al College of Sur: me gland Second edition, with additions, illu: 
Bay ‘ith 12 plates, and Rw bod engravings. London: H. Balliére, 219 Regent 
si Broadway, New York. 8vo, pp. 515. 2. Me 
“amp Serres, Vol. XIV, No. 40—July, 1852. 
ae 
ats 
