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Biography of Johann Nepomuk von Fuchs. 97 
his paper on gehlenite, Fuchs considers the peroxyd of 
iron which that mineral contains, “ not as an essential constituent 
of this species, but as only a vicarious ingredient, if such an ex- 
pression be permissible,—a substitute for nearly the same quan- 
tity of lime, which in the absence of the peroxyd of iron should 
be present to maintain the stcechiometrical relations of the min- 
eral,” and he remarks, “I believe that varieties will be found 
which contain much less or no iron, and a corresponding] 
greater amount of lime.” In the same article he mentions that 
sulphate of alumina can form alums, not only with potash, but 
with ammonia also, or with both together, and that Gehlen had 
also prepared a soda alum, which fact Fuchs connects with the 
attention to this subject, and laid the foundations of our knowl- 
ge concerning it. we 
In 1816, Fuchs published a preliminary notice of some min- 
eral phosphates, and two years later followed his researches on 
Lasionite and Wavellite. : ; ae 
ese investigations distinguished him as a profound analyst. 
He found that a mineral from Amberg which he named Lasionite, 
Was a compound of alumina, phosphoric acid and water, and af- 
ter he had overcome the difficulties in separating phosphoric acid 
this id inst the testimony of three most celebrated chemists, 
Klaproth, vy and Gregor, who had analyzed it and found noth- 
SECOND SERIES, VOL. XXIII, NO. 67,—JAN., 1867. " 
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