THE CHEMICAL AND NATURAL SCIENCES 209 



earth represents non-metallic minerals, salt the solu- 

 bility in water and solvent action on other bodies. 

 These ideas relate to ideal elements yet to be discovered, 

 and not to mercury, sulphur, earth and salt as known to 

 us through our senses. The discovery of these elements 

 would enable the transmutation of substances to be 

 effected, that is to say the transfer of a property from 

 one body to another. In particular it would be possible 

 to transmute any metal into gold. Only, the trans- 

 mutation must be effected in a certain order. 



As, in the eyes of modern chemistry, an element has 

 an affinity for certain known elements, so the alchemists 

 held the opinion that, although every body can be 

 transmuted into something else, this can only be done 

 by following an invariable order. For example, if F 

 represents iron and O gold, in order to transmute 

 F into it is necessary to give to F the property G, 

 then by means of G the property H, and so on up to O. 

 If one of the links be omitted, the transmutation will 

 not take place. Hence the famous symbol of the 

 serpent biting its tail. 



This investigation of the characteristic circular order 

 of the transfer of the properties of bodies could not 

 reach its goal, but it had the result of perfecting 

 metallurgy, the manufacture of glass and the remedies 

 employed in medicine, and discovered, by means of 

 distillation, several essences or spirits such as 

 turpentine. 



The history of chemistry is of a strange character. 

 From the fifth century B.C. Democritus had laid its 

 theoretical foundations. However, these were not 

 verified until after the work of Lavoisier at the end of 

 the eighteenth century. Until that time, practical 

 research gave rise to conceptions which, while doubtless 

 erroneous, seemed to be more in agreement with the 

 data directly furnished by experience. 



