9 Biography of Johann Nepomuk von Fuchs. 
In 1823, he was called to Munich and to the Academy of Sci- 
ences as Conservator of the national mineral collections, and 
when in 1826, the University was transferred from Landshut 
to Munich, he again entered the corps of professors, and in- 
_ structed in mineralogy 
I 
t 
n 1883 he was appointed to the Higher Medical Commission, 
and Counsel of Instruction, and in 1835 he was named Chief 
Mining and Saline Counsellor, at the same time retaining his pre- 
vious station. His new duties however were not of a kind com- 
patible with his devotion to investigation, so that he shortly de- 
sired to return to his old pursuits, and in 1844, in full acknowl- 
edement of his extraordinary ability he was pensioned as Chief 
Mining Counsellor, and was thus enabled to pursue undisturbed 
his manifold studies, which occupied him until 1852, when, at the 
age of 78 he was pronounced Privy Counsellor, and laid asi 
his active employments. Fuchs left behind him at his death a 
widow and one son. : 
The first considerable research of Fuchs was concerning the 
Zeolites, which he analyzed partly in connexion with Gehlen. 
This investigation was broken off by the death of the latter who 
rished from accidental poisoning by arseniuretted h en, | 
the year 1815, and Fuchs was so dejected at the loss of his friend 
that he would never have resumed it but for the severe criticisms 
of Hauy upon some of the results which had been published. - 
M adée 
oad because he considered the old analysis of Vauquelin, who 2 
? 
imperfections in the analytical method. The results of Fuchs 
were confirmed, and this controversy contributed to his reputa- 
tion. In another investigation relating to Aragonite and Stron- 
tianite, he also discovered some inaccuracies in the determina- 
tions of Hauy, and first directed notice to the great similari 
crystallization between aragonite and strontianite, witherite and 
earbonate of lead, as also between heavy spar, celestine and sul- 
phate of lead. Fuchs was then inclined to explain this similar- 
ity of form by the fact that these groups contain a common meni 
'; viz., their acid ingredient. If we combine these observa- 
| tions with an earlier paper of Fi 
uchs, w e wrote on instl- 
tuting the new species gehlenite, we find the elements of the 
doctrine of isomorphism that was subsequently announced by 
Mitscherlich. 
