542 IRON. 



SECTION II. 



IRON. 

 Eq. 339.2 or 27.18; Fe (ferrum). 



The most remarkable of the metals ; the production of which, 

 from the numerous and important applications it possesses, 

 appears to be an indispensable condition of civilization. Mete- 

 oric masses of iron, often so pure as to be malleable, are found 



effects, consequent upon the contact of different metals ; for one metal may 

 be affected by another metal, admitting the reality of their sali-molecular 

 structure, as well as by a salt or acid, the constitution of all these bodies 

 being the same. When copper, for instance, touches zinc, the chlorous ele- 

 ment of the copper molecule tends to leave its own zincous element, and to 

 combine with the zincous element of the zinc molecule ; so that a similar 

 disturbance takes place as if the zinc were touched by hydrochloric acid. 

 But the phenomena of the contact of metals belong to that class in which the 

 chemical action stops short of combination, the chlorous element of the copper 

 molecule attracting its own zincous element the less that it attracts likewise 

 the zincous element of the zinc, but not abandoning the former and combining 

 with the latter. They belong to the class of the open, and not of the closed 

 circuit. Sulphur, dry acids, peroxides, and many other bodies, disturb the 

 molecular affinities of the metals they touch, in the same manner. The sali- 

 molecule of the highly negative metals, gold, platinum, mercury, &c., contains 

 a strong salt-radical, united with a weak basyle, and resembles hydrochloric 

 acid and the hydrates of the strong acids ; while the sali-molecule of the 

 highly positive metals, potassium, zinc, &c., contains a powerful basyle and 

 weak salt-radical, like the hydrated alkalies. In an alloy of two metals, the 

 whole positive metal may exist as basyle, and the negative metal as salt- 

 radical ; as in the crystallizable amalgam of cadmium, Cd Har 2 . The sali- 

 molecule of iron is difficult of decomposition, hence the unusual difficulty 

 of alloying that with other metals, and the tendency of the iron molecule to 

 combine, as a whole, as in the magnetic oxide. 



3. The reaction of the sali-molecules of different metals upon each other, 

 when heated, appears to be the cause of the phenomena of thermo-electricity, 

 (page 226), but these are phenomena of the closed circle. It will be evident 

 to those who are acquainted with the Contact Theory of galvanism, so ably 

 developed by Ohm, and supported by the German electricians, and which 

 embraces so happily the whole circle of the phenomena, that the chemical 

 view, advocated here, although founded on a different fundamental assump- 

 tion, has a more perfect consistency and parallelism in its details with that 

 theory than the electro- chemical theory, generally received, possesses. (Tay- 

 lor's Scientific Memoirs, No. 7-) 



4. The relation of the phosphorus group of elements to the magnesian 

 elements appears to be this : the equivalent of phosphorus, nitrogen, anti- 



