298 A CENTUKY OF SCIENCE 



volumes of hydrogen and oxygen about the year 1891. 

 Some of his publications have appeared in the Journal 

 (30, 140, 1885; 41, 220, 1891; and others). 



Electrolytic analysis, involving the deposition of 

 metals, or sometimes of oxides, usually upon a platinum 

 electrode, was brought into use in 1865 by Wolcott Gibbs 

 through an article published in the Journal (39, 58, 1865). 

 He there described the electrolytic precipitation of cop- 

 per and of nickel by the methods still in use. The appli- 

 cation of the process has been extended to a number of 

 other metals, and it has been largely employed, particu- 

 larly in technical analyses. Important investigations 

 and excellent books on this subject have been the contri- 

 butions of Edgar F. Smith of the University of Pennsyl- 

 vania, and the useful improvement, the rotating cathode, 

 was devised by Gooch and described in the Journal (15, 

 320,1903). 



General Inorganic Chemistry. 



The Chemical Symbols. It is to Berzelius that we owe 

 our symbols for the atoms, derived usually from their 

 Latin names, such as C for carbon, Na for sodium, Cl for 

 chlorine, Fe for iron, Ag for silver, and Au for gold. 

 "We owe to him also the use of small figures to show the 

 number of atoms in a formula, as in N 2 5 . This was a 

 marked improvement over the hieroglyphic symbols pro- 

 posed by Dalton, which were set down as many times as 

 the atoms were supposed to occur in formulas, forming 

 groups of curious appearance, but in some respects not 

 unlike some of our modern developed formulas. The 

 advantages of Berzelius 's symbols were their simplicity, 

 legibility, and the fact that they could be printed without 

 the need of special type. It is true that at a later period 

 Berzelius used certain symbols with horizontal lines 

 crossing them to represent double atoms, and that these 

 made some difficulty in printing. It should be mentioned 

 also that Berzelius at one time made an effort to simplify 

 formulas by placing dots over other symbols to represent 

 oxygen, and commas to represent sulphur atoms. Exam- 

 ples of these are : 



> 



CaS, calcium sulphate ; Fe, iron disulphide 



