204 Biography of Berzelius. 



the same time he observed that metals unite with double 

 (exactly or very nearly) as much sulphur as oxygen, and that 

 by a simple rule of three, the capacity of combination of any 

 metal for sulphur may be calculated from its oxide, or the 

 contrary. He was now again led to study the mutual de- 

 composition of neutral salts, and he finally succeeded in prac- 

 tically demonstrating, from the composition of several salts, 

 the neutrality of those resulting from their decomposition. 



I feel myself justified in mentioning the following cir- 

 cumstance, although somewhat of a personal character. Ber- 

 zelius, after being unable to prove by calculation the neu- 

 trality of salts mutually decomposing each other, while basing 

 his calculations upon the data of incorrect analysis, was 

 often nearly abandoning the perplexing subject, but was in- 

 duced by a paper of my father, upon the relation of the 

 constituents of neutral muriates (published by him in 1806, 

 a year before his death, in the 6th volume of " Gehlen's 

 Neuem. Allg. Journal" p. 22), to persevere. My father had, 

 in the first place, by at least one example, practically demon- 

 strated, that by the decomposition of two neutral salts, mu- 

 riate of baryta and sulphate of soda, according to his own 

 analysis of them, and of the two salts resulting from the 

 decomposition, and by calculation, results were obtained, 

 which proved that the neutrality could not be disturbed. 



Berzelius now considered it necessary, in order to attain 

 to certain results, to investigate anew the composition of the 

 most important compounds with extreme care, repeating the 

 analyses several times before venturing to employ their re- 

 sults in the extension of his views. He remarked very justly, 

 that, on account of the unchangeable neutrality of two salts 

 decomposing each other, it was only necessary to ana- 

 lyse, with sufficient accuracy, all salts formed for example 

 by sulphuric acid, and all those whose base is baryta, in 

 order to be able, by a simple rule of three, to calculate the 

 composition of all other salts, because these two series con- 

 tain the three numbers which are necessary in order to find 

 the fourth. 



Berzelius now ventured upon an herculean task, which he 

 prosecuted for many years with the most indefatigable in- 



