ON THE PRIMITIVE FORMS OF CRYSTALS. 55 



4>. Eight Quadrangular Prism, — Base an Ob- 

 lique Parallelogram, 

 Sulphate of lime. 

 Epidote. 

 Axinite. 



5. Oblique Quadrangular Prism, — Base a Bee- 



tangle, 



Borax. 



6. Oblique Quadrangular Prism, — Base aRhomb 



Diopside. 



Augite. 



Glauberite. 



Sulphate of iron *. Wollaston, Annals of Phil. 



vol. xi. p. 284. 

 Super-sulphate of potash, 

 Acetate of copper. j jj^^ m 



Tartaric acid. 190> lgi> m 



Oxalic acid. 



Sugar. J 



Grammatite. 



7. Oblique Quadrangular Prism, — Base an 



Oblique Parallelogram. 

 Felspar. 

 Kyanite. 



Sulphate of copper. 



* Sulphate of iron is supposed by Haiiy and Beudant to 

 have the acute rhomboid for its primitive form ; but Dr Wol- 

 laston ha shewn it to be a rhombic prism. Although M. Beu- 

 dant persists in his first opinion, yet we consider the existence of 

 two axes as a proof of the correctness of Dr Wollaston s result. 



