CHEMICAL ACTION. By acting chemically what is 

 meant is so affecting each other that the substances are 

 greatly altered in properties. A mixture of oxygen 

 and hydrogen is still a gas; a chemical compound of 

 oxygen and hydrogen is a liquid, namely, water; 

 here is a great alteration in leading properties. 

 Iodine is only slightly soluble in water, and forms 

 a brown-colored solution, and iron is insoluble; but 

 when iodine and iron are chemically combined, the 

 product is very soluble in water, forming a light- 

 green solution in which the eye can detect neither 

 iodine nor iron, and which is utterly unlike iron or 

 iodine in any one of their properties. 



Tartaric acid, carbonate of sodium, and water add- 

 ed to each other, form a chemical compound, con- 

 taining neither tartaric acid nor carbonate of sodium, 

 these bodies having attacked each other and formed 

 fresh combinations. These illustrations show that 

 chemical action is distinguished from all other actions 

 by (a) producing an entire change of properties in 

 the bodies on which it is exerted. Chemical action 

 is further distinguished by (b) the fact that it only 

 takes place between definite weights and volumes of 

 matter. This (a and b] cannot be said of any other 

 action the action of any of the other great forces 

 of nature (gravitation, heat, light, electricity, etc.); 

 hence the statements (a and b] furnish a sharp and 

 precise definition of chemical action or the chemical 

 force. 



ATOMS. In a chemical compound, what has become 

 of the constituents? Let the reader place before him 

 specimens of sulphur, iron, and sulphide of iron. In 

 the sulphide of iron what has become of the sulphur 

 and of the iron from which it was made? TfanriJfturv 

 of sulphur and iron in combining to form sulphide of 

 iron has not lost weight, and, indeed, by certain proc- 



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