614 



HISTORY OF SCIENCE. 



The notation of Berzelius was, like all other inventions and dis- 

 coveries, an evolution. The old alchemists used symbols, some of 

 which may be seen on the bottles in the chemists' shops to this 

 day. Dalton more rationally indicated his non-metallic atoms by dis- 

 tinguishing marks enclosed in little circles and the atoms of the 

 metals by placing the initial letter of each within the circles. This 

 mode of representation, excellent for simple combinations, was cum- 



FIG. 312. JACOB BERZELIUS. 



brotis and unwieldy when many atoms had to be indicated. Ber- 

 zelius dispensed with the circles, and made the initial letter of the 

 Latin name of each element the symbol of the atom. H repre- 

 sented an atom of hydrogen, O an atom of oxygen, S an atom of 

 sulphur, Sb an atom of antimony (stibium), K an atom of potassium 

 (kalium). A compound was indicated by the symbols of its consti- 

 tuents placed side by side, thus : KO stood for oxide of potassium, and 

 when several atoms of the same element were to be grouped together, 

 Berzelius, instead of repeating the symbol, wrote a small figure after 

 it : thus, instead of SOOO for sulphuric acid, he wrote SO 3 or SO 3 . 

 Another device was the employment of dots to express oxygen atoms 

 in combination : thus, S. 



