178 Biography of Berzelius. 
termed by the editor of an English journal? The opposition to 
the introduction of these symbols was the more remarkable, sin 
Dalton, in putting forward his atomic system in 1808, had felt 
e urgent necessity of representing the atoms of elements by 
means of symbols, which did not then meet with any opposition, 
although at the same time with no imitation in England. The 
five, and seven atoms of oxygen, because these numbers were not 
multiples of each other. He therefore assumed, that in phosphoric 
acid there were four atoms of oxygen, in the arsenious and arsenic — 
acid four and six atoms, and in oxide of antimony and antimoni¢ 
acid the same number; and long after he had convinced himself 
of the elementary nature of chlorine, he doubted the correct state- 
ment of Stadion, that hyperchloric acid contained seven atoms of 
oxygen. 
‘The examination of the oyxds of nitrogen presented consider- 
able difficulties to him. As ammonia was analogous to the fixed 
alkalies, and under the influence of galvanic electricity yielded an 
amalgam with mercury, there was a possibility of assuming that 
this was a process of reduction, and that ammonia consisted of 2 
metal and oxygen. But when ammonia was decomposed, no 0X- 
