CHROxMITE AND PICOTITE. 185 



tine, pyroxenes, aniphiboles, and in almost every mineral or group of minerals 

 that has been studied to a sufficient extent to afford us much information 

 about its composition. Our minerals in Nature's laboratory appear to be 

 produced and grow, to change and decay, to pass away and be succeeded by 

 others, ever passing onward from the unstable towards the more stable ; re- 

 action after reaction, replacement after replacement, following one another 

 according to the varying conditioi?s, as they do in the chemist's laboratory. 

 When we can learn the order of succession by alteration, and the various 

 relations minerals thus hold to one another, we may hope for a natural sys- 

 tem of mineralogy, which will display to us their origin and line of descent, 

 with their relationships. In the establishment of such a system, the micro- 

 scope and chemical reagents must go hand in hand, and the work is yet 

 hardly begun. 



An analysis of a chromite from Ruraas, Norway, given in Table I., has had 

 a strange history. It was attributed to Laugier by Rammelsberg in his 

 Handwcirterbuch des chemischen Theils der Mineralogie, 1841, pp. 163, 164, 

 and in his Handbuch der Mineralchemie, 1860, pp. 171-174 ; and from these 

 works of Rammelsberg it has been copied in the third, fourth, and fifth 

 editions of Dana's System of Mineralogy, and elsewhere. The work from 

 which the analysis is said to have been taken is the sixth volume of the Ann. 

 Mus. d'Hist. Nat. It was proved by the present writer not to occur there, 

 and after a long search, its history has been found to be as follows : — 



The analysis was published in the Annales des Mines, 1829 (2), V. 316, 

 as taken from the " An. du Bureau des mines de Suede, t. 9, 1825," but the 

 name of the analyst w^as not given. Since the writer is unable to see, for 

 the present at least, the Swedish journal referred to, the analysis has not 

 been traced any further backwards. It was then copied, by Beudant,* 

 together with an analysis of Seybert, but in both cases without mention of 

 the analyst or the source. Before this, however, it had been republished by 

 Franz von Kobell,t without being attributed to any analyst, and without 

 reference to the original source, but placed after a reference to an analysis 

 by Laugier. Tiiis then evidently gave rise to Rammelsberg's mistake; while 

 it also led Hausmann t and Brooke-and-Miller§ to attribute the analysis to ^'on 

 Kobell himself, as they have done in their mineralogies. Thus this analysis 



* Traite elemeiitaire de Mineralogie, 1S32, ii. G67, 0G8. 

 f Charakteristik der Mineralien, 1831, ii. 255. 

 X Handbuch der Mineralogie, 1847, ii. 420. 



§ An Elementary Introduction to Mineralogy, by the late William Phillips, 1S52, p. 2().3. 



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