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ML Fischer's Memoir of the Life of Klaproth, 
timate mixture of siliceous and argillaceous earth. Indeed, the 
first analyses that can be considered as certain, are those which 
have been undertaken on this plan. Hence, by this discovery, 
almost all the more early analyses have lost their value. Of 
what inestimable moment such a discovery must be, not merely to 
experimental chemistry, but to the whole of the science of nature, 
even although Klaproth had not discovered by means of it a single 
unknown body, does not require to be more particularly stated. 
In the numerous exact analyses which Klaproth conducted 
according to this method, there was almost always discovered at 
last to be a small loss, that is to say, the weight of all the single 
component parts was ascertained to be somewhat less than the 
weight of the mineral which had been analysed. Fie in every 
case stated this loss with great precision, and by this incorrup- 
tible regard to truth, he obviously procured for the results of 
his labours a much greater certainty than if he had permitted 
himself, as he might easily have done, to conceal this loss under 
inconsiderable changes in the decimal figures. He also never gave 
his results, as he likewise easily might have done, in a great crowd 
of decimals, by which means the appearance of much exactness 
is sometimes gained, but he gave only as many cyphers as were 
sure. As long as the loss amounted only to a few thousand 
parts of the whole, it might easily be referred to those small 
mistakes which in every course of experiments are unavoidable, 
from the limited nature of our senses and instruments. But, 
in some analyses, as for instance, in that of Felspar, a loss of 
some hundred parts was discovered. Such a loss, considering 
the care with which Klaproth laboured, could only arise from 
some of the constituent parts having entirely escaped observa- 
tion during this method of resolution. Convinced that this 
could be neither an earth nor a metal, nor an acid, nor water, 
nor any other volatile matter, he at last began to suspect that 
perhaps many minerals might contain a hitherto unsuspected quan- 
tity of fixed alkali, which could not be discovered by the method 
of analyses by means of these alkalies. This consideration led 
to Klaproth's second great invention, I mean, the method of 
analysis by means of Barytes, although, as was formerly re- 
marked, the excellent Rose had no inconsiderable part in this 
invention. The event justified Klaproth's suspicion, since he 
