Early Works. 



through Germany, France, and England. Od this trip 

 he received an invitation ( L823) from the banker, Thomas 

 Allan, of Edinburg, to stay al his house to study and ar- 

 range his greal collection of minerals. 3 During three 

 years he remained with Allan, translated Mohs' treatise 

 on mineralogy into English, improving this edition by 

 many original observations (1825). Besides, he pub- 

 lished some of the results of his labors in separate papers, 

 in the Memoirs of W^ernerian Society, in the Philosoph- 

 ical Transactions of the Royal Society, and in Brews- 

 ter's Journal of Science, One of the most important of 

 these papers demonstrated the true form of chalcopy- 

 rite to be quadratic, instead of tessoral, as assumed by 

 Hauy.f This publication (1821) fairly proved Haiding- 

 er's high position as crystallographer ; for the crystals of 

 chalcopyrite are not only rather imperfect, and compli- 



d, by twin formations, but the difference between 



ral and quadratic form determined by him was but 

 very small. He found the vertical axis to be 0.98556, 



ad of 1.00000, or only 0.01444 shorter than thai of 

 the tesseral form. His investigations on the peculiar 

 kind of hexagonal hemihedry of apatite and scheelite 



also published during Ids sojourn in Edinburg. 'I'm 

 papers have to be added his careful discrimination 

 of five species of manganese minerals (m&nganite, pyrolu- 

 sit<-. hausmannite, braunite, andpsilomelane); his papers 

 on pseudomorphs, on twin crystals, and many others. 

 The debut of Eaidinger as an independent investigator 



indeed most successful. 

 From July, l s _!~>. until December, l s _o. Baidinger 



mpanied Robert Allan, the son of the munificent 

 banker, Thomas Allan, above referred to, on a scientific 

 tour through Norway, Sweden. Denmark, Germany, 



rwartk acquired by Che British Museum. 



mistry,p.l27; Principles of Crystallography, p. 85 



