Biography of Berzelius. 185 
after making slight alterations in the results of the then known 
analyses, in doing which, however, he always proceeded with 
great caution. Afterwards these incorrect analyses were replaced 
Y correct ones, and especially by Berzelius himself and his pu- 
pils, who employed in their analyses the most accurate methods 
proposed by him. 
__ Berzelius first arranged minerals according to their electro-pos- 
itive constituents. But after Mitscherlich’s discovery of isomor- 
phism, which has exerted so important an influence upon the 
arrangement of the system, he considered it more advantageous to 
classify minerals according to their electro-negative constituents, 
because the substitution of isomophous substances is far more fre- 
quent among the bases than among the acids; and therefore the 
classification according to the electro-negative constituents cor- 
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methods have their advantages: they are equally philosophical, 
and may be employed with equal justice; it was therefore with 
great injustice that Berzelius was charged with inconsistency in 
making this alteration. 
The mineral system of Berzelius is not even yet completed. 
He was far from wishing to affirm that it was incapable of im- 
provement ; on the other hand, during his whole after-life he.con- 
unually improved it, and from time to time published it in a more 
periees form. The last edition was superintended by Rammels- 
rg, in 1847, at the request of Berzelius. 
The most important modifications still to be made on this sys- 
tem, are perhaps those which would result from a simple applica- 
tion of the doctrine of isomorphism. It is certainly difficult to 
harmonize the opinions as to the best method of doing this. _ 
Berzelius was not quite right in affirming that the constit- 
uents of a substance alone must determine its place in a sys- 
tem. Even in the last “‘Jahresberichte” published by him, he 
Srconp Serres, Vol. XVI, No. 47.—Sept., 1853.. 24 
