GENERAL REMARKS REGARDING ELEMENTS. 



61 



Another number of elements are of less importance, because either 

 they are not found in any large quantity, or do not take any active 

 or essential part in the formation of organic matter ; yet they are of 

 interest and importance on account of being used, in their elementary 

 state or in the form of different compounds, in every-day life for 

 various purposes. 



A third number of elements are found in such minute quantities 

 in nature that they are almost exclusively of scientific interest. Even 

 the existence of some elements, the discovery of which has been 

 claimed, is doubtful. 



The elements enumerated in column I. are those of great and gen- 

 eral interest ; in II. those claiming interest on account of the special 

 use made of them ; in III. those having scientific interest only. 



I. II. III. 



Aluminum Antimony Beryllium (Glucinum) 



Calcium Arsenic Caesium 



Carbon Barium Columbium (Niobium) 



Chlorine Bismuth Didymium 



Hydrogen Boron Erbium 



Iron Bromine Gallium 



Magnesium Cadmium Germanium 



Nitrogen Cerium Indium 



Oxygen Chromium Iridium 



Phosphorus Cobalt Lanthanum 



Potassium Copper Osmium 



Silicon Fluorine Palladium 



Sodium Gold Ehodium 



Sulphur Iodine Kubidium 



Lead Ruthenium 



Lithium Samarium 



Manganese Scandium 



Mercury Selenium 



Molybdenum Tantalum 



Nickel Tellurium 



Platinum Terbium 



Silver Thallium 



Strontium Thorium 



Tin Titanium 



Zinc Tungsten 



Uranium 

 Vanadium 

 Ytterbium 

 Yttrium 

 Zirconium 



Classification of elements may be based upon either physical or 

 chemical properties, or upon a consideration of both. A natural 



