235 



CrystaUograph y . 



li. Wooden model of Sulphate of Magnesium. (Rigid rhom- 

 bic prisms.) Two specimens. 

 t. Very fine crystal, presented by Mr W. Copney. 

 Note. For figures of these models, see Phillips' Transl. Pltarm., p. 327, 

 fig. 1, 2. The specimen t is a large, nearly rectangular, prism (inclining 

 to rhombic), with reversed dihedral summits. It was made by a pro- 

 cess, of which the details will be found in P. ./., vol. x.. p. 536. 



j. Wooden model of Sulphate of Potassium. Three speci- 

 mens. 



Note. For figs, of these specimens, see Per. Mat. Med., vol. i., p. 503, 

 figs. 78-81. The larger model, represented by fig. 80., is a compound 

 crystal, as well as the smaller model (fig. 78), which bears a close resem- 

 blance to crystals of the prismatic system. The other model (fig. 78) is 

 a right rhombic prism. 



k. Wooden model of Sulphur, as it crystallizes in the native 



state. Two specimens. 



Note. For fig., see Per. Mat. Med., vol. i., p. 353, fig. 55. This speci- 

 men is an acute rhombic octohedron. See also Watts' Diet. Chetn., vol. 

 v., p. 530., fig. 782. 



I. Wooden model of Potassio-tartrate of Antimony. ( Octa- 

 hedron with a rhombic base.) 

 Note. For fig., see Phillips' Transl. Pharm., p. 260. 

 m. Wooden model of Nitrate of Silver. (Right rhombic 



prism.) 

 Note. For fig., see Per. Mat. Med., vol. i., p. 507. 



7i. Wooden model of Bichloride of Mercury. (Eight rhombic 



prism.) 



Note. For fig., see Phillips' Transl. Pharm., p. 312. 

 o. Wooden model of Sulphate of Zinc. (Eight rhombic 



prism.) 



Note. For fig., see Phillips' Transl. Pharm., p. 378. 

 p. Wooden model of Bitartrate of Potassium. (Eight 



rhombic prisms.) Two specimens. 



Note. For fig., see Phillips' Transl. Pharm., p. 266, figs. 1, 2. 

 CG4. V. OBLIQUE PRISMATIC STSIEM. (Monoclinic system.) 



a. Glass model showing the following forms. 



Yellow, oblique rhombic octahedron. 



Slack lines on the glass, oblique rhombic prism. 



Then-hole of the model, oblique rectangular prism. 



b. Crystal of Sugar. (Oblique rhombic prism.) 



Note. This specimen is a large perfect crystal, but is not quite 

 transparent. Presented by Mr. W. W. Stoddart. 



c. Wooden model of Sulphur, as crystallized after fusion 



and slow cooling. 

 Note. For fig., see Per. Mat. Med., vol. i., p. 353, fig. 56. 



