A Sketch of the Laws of Chemical Combination. 



311 



NegativeElectrics. 1 4. Tu ngsten 



may be increased by more extended research ; or, on the other hand, that 

 improved modes of analysis may show that several of those now considered 

 simple, may prove to be modifications of one another. They have been 

 arranged by Berzelius in the following order as regards their electrical 

 properties, which are principally deduced from their relative affinities for 

 oxygen. (Op. cit. p. 49.) 



28. Palladium 



29. Mercury 



30. Silver 



31. Copper 



32. Uranium 



33. Bismuth 



34. Tin 

 35. 

 36. 

 37. 

 38. 



1. Oxygen 



2. Sulphur 



3. Nitrogen 



4. Fluorine 



5. Chlorine 



6. Bromine 



7. Iodine 



8. Selenium 



9. Phosphorus 



10. Arsenic 



1 1. Chromium 



12. Vanadium 



13. Molvbdenum 



15. Boron 



16. Carbon 



17. Antimony 



18. Tellurium 



19. Columbium 



20. Titanium 



21. Silicon 



22. Hydrogen 



23. Gold 



24. Osmium 



25. Iridium 



26. Platinum 



27. Rhodium 



Lead 

 Cadmium 

 Cobalt 

 Nickel 

 39. Iron 



40. Zinc 



41. Manganese 



42. Cerium 



43. Thorium 



44. Zirconium 



45. Aluminium 

 A^. Yttrium 

 AT . Glucinum 



48. Magnesium 



49. Calcium 



50. Strontium 



51. Barium 



52. Lithium 



53. Sodium 



54. Potassium 

 Positive Electrics. 



In the opinion of Sir H. Davy, and also of Berzelius, chemical affinity is 

 identical with electric attraction ; and whether this view (which is favoured 

 by the recent discoveries of Dr. Faraday) be adopted to its full extent, or 

 not, there can be no doubt that a great connection and correspondence 

 exists between these two forces. When a compound body is decomposed 

 by electric agency, one ingredient is always attracted to the positive pole, 

 and is therefore considered to have electro-negative properties ; whilst the 

 other goes to the negative pole, and is considered to be electro-positive. 

 The elementary substances have accordingly been arranged under two 

 classes ; the first, or electro- negative, including oxygen and the acids ; the 

 second, or electro-positive, comprehending hydrogen and the alkaline bases. 

 But a strong objection arises to such an absolute division, from the fact 

 that most bodies exhibit positive or negative qualities according to the 

 nature of the combinations into which they enter. For instance, sulphur 

 and phosphorus unite as positive bodies with oxygen, (which stands at the 

 electro-negative extremity of the scale, and is consequently never positive) 

 so as to form sulphuric and phosphoric acids ; but they are the negative 

 ingredients of the sulphurets and phosphurets of the metals, which are 

 nearer the positive end of the scale. In general, all substances are positive 

 to those above them, and negative to those below tliem ; but this rule is by 

 no means constant, as the relative strength of affinities is very much affected 

 by temperature and otiier circumstances. Thus iron has no action upon 

 potash when cold, but at a white heat deprives it of its oxygen, and is 



