Biography of Berzelius. 307 
The first of these researches was upon the ferruginous cyano- 
cyanogen, had neglected to study these compounds. After him, 
several chemists had occupied themselves with their examina- 
tion, but all obtained very different results, the greater number, 
owever, assuming that the iron in the so- -called ferro- asinbid acid 
salts was an essential constituent of the acid, which was combined 
in the salts with an oxydized body. 
Berzelius, however, shewed that these salts contained neither 
prussic acid nor oxydized hases, but that they consisted of cyanid 
combined with the eyanid of an alkaline metal, and conse- 
quently were double cyanids. He also extended his investiga- 
tions to the salts of the so-called sulpho-cyanic acid, and shewed 
that they consist of a metal, sulphur, and cyanogen, the latter 
two united to form a radical (which he subsequently called Rho- 
dan); and — in se likewise there was neither prussic acid 
nor oxydized ba 
hese ieieliohien tlie which fully confirmed the views of Gay- 
Lussac regarding cyanogen, were, however, of still greater im- 
portance to Berzelius in another respect. After Davy had been 
induced, by his researches in 1810, to consider that it was simpler 
and more correct to look upon chlorine as elementary, and not, as 
he had formerly done, as a “bar of oxygen with a radical 
that had not been isolated ; most chemists concurred with him in 
this view. Gay-Lussac Aes Thénard, who, even before Davy, 
considered a similar view possibly correct, although not oideait 
more probable than the old one, after the discovery of iodine, 
openly declared a with Vauquelin and all the other 
French chemists, in favor of the new doctrine; and the famous 
paper of Gay-Lussac a iodine, which appeared in 1813, is 
written in this spirit. 
Berzelius alone, who from the first had disputed the hypothesis 
of Davy, continued to defend the old doctrine, even after the dis- 
covery of iodine. He did this —s in a paper which first 
appeared in Gilbert’s Annalen for 1815. He there endeavored, 
with a profound sagacity which must be highly admired by every 
one, on reading the paper even after the lapse of so long a time, 
to prove the truth of the doctrine of the compound nature of 
chlorine. He directed attention to the remarkable phenomenon 
that the constituents of chlorid of nitrogen, which are united only 
by a very feeble affinity, separate with such an energetic evolu- 
tion of heat as is never observed except in chemical combinations. 
But above all he pointed out the analogy which existed between 
muriates, which, according to the new theory, in the anhydrous 
State contain no oxygen, and the sulphates, phosphates, and other 
salts, which are indisputably compounds of oxygen acids _ 
oxygen bases, and in which the presence of oxygen may be 
readily detected. 
