Biography of Berzelius. 179 
toxyd of ammonium (the present amidogen combined with potas- 
sium), ammonia, nitrogen, nitrous acid, nitric acid, and, finally, 
water, the highest oxyd of the radical, which, however, must, on 
this view, have contained 72 times as much oxygen as the low- 
est oxyd hydrogen. 
Berzelius was led to adopt this extravagant but ingenious view 
by too great faith in the doctrine of proportions in the form in 
which he then conceived it. Somewhat later, he retracted the 
opinion that hydrogen was an oyxd, and demonstrated the ele- 
mentary nature of this body by weighty arguments; but he still 
continued to regard nitrogen as containing oxygen, and endeav- 
ored afterwards to prove this by means of its oxyds. Even in 
1818, in a paper upon the nature of nitrogen, hydrogen and am- 
monia, he said, “I venture to assert, that the compound nature of 
nitrogen must not be regarded as a mere hypothesis, but, if the 
doctrine of definite proportions is admitted, as a demonstrated 
truth.” He assumed that an unknown radical—nitricum—ex- 
isted, to which he assigned the symbol N, subsequently retained 
for nitrogen, which-was then regarded as the suboxyd of thi 
supposed radical, and the highest oxyd—nitric acid—as contain- 
ing six atoms of oxygen 
Searches on the composition of phosphorus and phosphoric acids, 
in which he found, almost simultaneously with Dulong, that the 
quantities of oxygen were in the proportion of 3 to 5, and after 
aving in vain attempted to detect oxygen in phosphorus, his 
Views respecting the compound nature of nitrogen were shaken, 
and he finally relinquished them, after having convinced himself 
that a similar relation obtained between very many, we may per- 
haps now say most, of the different oxyds of simple bodies which 
form acids. Subsequently, he sometimes made the remark, without, 
vestigation of the oxyds of tin, he assumed that the oxyd obtained 
from the Spiritus Libavii, which certainly differs greatly in its 
