360 Scientific Intelligence. 



sulphate of lime filtered out. The solution, being diluted with water, is 

 decomposed by carbonate of soda in slight excess, and the precipitate well 

 washed, dried, and heated to redness. It is then a perfectly pure and 

 beautifully white oxide. — Quarterly Journal of Science for October 1827. 



III. NATURAL HISTORY. 

 MINERALOGY. 



21. On Herderite, a New Mineral Species. By W. Haidinger, Esq. 

 F. R. S. E. — 1. General Description. Fundamental form, a scalene four- 

 sided pyramid, P = 141 c 16', 77° 20', 116° 3'. (Plate IV. Fig. 8.) Ratio 

 of the axes a : b : c = 1 : J '2.55 : *Jo.4>ti. 



Simple forms. (P— 2) 4 (o) = , 149° 50', ; (£ p— 2)3 



(n) = , 134° 35^, ; P (p) ; (Pr+ cd )* (,) = lU ° 7> ; 



(P+ «y (*) = 42° 58'; Pr (M) = 115° 53' ; Pr+ «> (r) ; Pr + ao (p.) 



Combinations observed. 1. Pr . P . (Pr+ oo)5 , p r -f- oo . (Fig. 9.) 

 2.Pr.(P-2) 4 .(£P— ^2) 3 .P.(Pr+<») 3 .(p+oo) 6 .p r +cx) & .p74. a) . 



Cleavage distinct, parallel to the faces M, but interrupted ; also perpen- 

 dicular to the axis, the latter only in detached portions of very bright and 

 even faces, and faint indications parallel to P. Fracture small conchoidal. 



Surface, M very smooth, and delicately streaked parallel to its edges of 

 combination with P, and resembling in this respect all the faces of the py- 

 ramids, w, o, and p, situated between them. 



The faces r and s are very narrow, and somewhat curved. Those mark- 

 ed t and P, have a peculiar granulated aspect, but they are at the gome 

 time pretty smooth, particularly the latter. 



Lustre, vitreous, slightly inclining to resinous. Colour several shades 

 of yellowish and greenish-white; streak white, strongly translucent. 



Very brittle. Hardness = 5.0, equal to that of apatite. Specific gra- 

 vity =2.985. 



2. Observations — 1. The only specimen of herderite, at present known, 

 is in the Wernerian Museum at Freiberg. It was pointed out to me by 

 M. Von Weissenbach, then keeper of the museum, as containing crystals, 

 whose forms he could not exactly refer to those of apatite, among the va- 

 rieties of which it was exhibited. The different aspect of the faces p and 

 t, the former being smooth or but faintly streaked parallel to their inter- 

 sections with P, while the latter are granulated, showed that the forms did 

 not belong to the rhombohedral but to the prismatic system ; and I did 

 not hesitate in pronouncing the mineral to be a new species, which I re- 

 quested permission to examine more minutely. This permission was very 

 liberally conceded. Mr Breithaupt, who was then present, and had him- 

 self at a former period placed the specimen in the cabinet of Werner, like- 

 wise concurred in acknowledging the species to be a new one. 



Through the kind intercession of Mr Reich, now keeper of the museum, 

 I was favoured, during my stay at Berlin in the winter of 1825, with 

 some fragments of the specimen for analysis, by Baron Von Herder, the 



