208 Biography of Berzelius. 



during his latter years, in the summer of 1816, when his 

 labours were often interrupted by repeated attacks of illness. 

 I was therefore enabled, while afterwards working for several 

 years in the laboratory of Berzelius, to compare the different 

 manner in which Klaproth and Berzelius worked. Their 

 methods had exactly the same relation to each other as the 

 respective accuracy of their results. 



Even previously to Berzelius, Dalton had, in his new Sys- 

 tem of Chemical Philosophy, attempted to express numerically 

 the relative quantities in which bodies generally combine, and, 

 as he regarded bodies as consisting of atoms, by this means 

 to establish as it were the relative weights of the ultimate 



atoms. Thus originated the doctrine of so-called atomic 

 • i 1 



w pi o'hts 



lo Dalton, therefore, belongs the great merit of having 

 given the correct idea of that which is now universally called 

 atom in chemistry. Richter had previously employed in a 

 similar sense the name relative mass (massentheil), in order 

 to express the different quantities of acid and base which 

 combine together forming salts ; however, his idea was not 

 so material as that of Dalton, and this character was necessary 

 for giving it that perfect clearness, indispensable, if a theory 

 was to be founded upon it. The long and obstinate opposi- 

 tion which was made to the idea of atoms, such as must be 

 employed in chemistry, by German philosophers, and the war 

 waged against the atomic view of the composition of bodies, 

 with all the weapons of logical acumen, for a long time rather 

 obstructed than favoured the advancement and spread of 

 the exact sciences, especially chemistry. Now that the atomic 

 theory is adopted by all, every one will certainly make use of 

 the word atom, in order to explain the phenomena with ease 

 and simplicity. 



Dalton assumed that simple substances combined in equal 

 atoms, and, indeed, atom with atom, when there was only 

 one compound of the two elements ; if several, one atom of 

 one substance combined with one, two, three, or more atoms 

 of another. The first conception of these so-called multiple 

 proportions originated properly with Higgins, who made it 

 known as early as 1789, in a work on the subject. But the 



