ALCHEMY. 



himself entirely to alchemy, and who lived in the year 730 A.D. He 

 fancied gold would cure all disease, and he did actually discover corrosive 

 sublimate, nitric acid, and nitrate of silver. To give even a list of the noted 

 alchemists and magicians would fill too much space. Raymond Sully, 

 Paracelsus, Friar Bacon, Albertus Magnus, Thomas Aquinas, Flamel, Bernard 

 of Treves, Doctor Dee, with his assistant Kelly, and in later times Jean 

 Delisle, and Joseph Balsamo (Cagliostro), who was one of the most notorious 

 persons in Europe about one hundred years ago (1765-1789), are names 

 taken at random ; and with the older philosophers chemistry was an all- 

 absorbing occupation not for gold, but knowledge. 



The revelation was slow. On the temperature of bodies the old arts 

 of healing were based for chemistry and medicine were allies. The elements, 

 we read, existed on the supposition " that bodies were hot or cold, dry or 

 moist " ; and on this distinction for a long time " was based the practice of 

 medicine." The doctrine of the " three principles " of existence superseded 

 this, the principles being salt, mercury, and sulphur. Metals had been 

 regarded as living bodies, gases as souls or spirits. The idea remained 

 that the form of the substance gave it its character. Acid was pointed ; 

 sweet things were round. 



Chemistry, then, has had a great deal to contend against. From the 

 time of the Egyptians and Chinese, who were evidently acquainted with 

 various processes, dyeing, etc., the science filtered through the alchemists 

 to Beecher and Stahl, and then the principle of affinity a disposition to 

 combine was promulgated, supplemented in 1674 by Mayow, by the theory 

 of divorce or analysis. He concluded that where union could be effected, 

 separation was equally possible. In 1718 the first " Table of Affinities " 

 was produced. Affinity had been shown to be elective, for Mayow pointed 

 out that fixed salts chose one acid rather than another. Richter and Dalton 

 made great advances. Before them Hales, Black, Priestley, Scheele, Lavoi- 

 sier, and numerous others penetrated the mysteries of the science whose 

 history has been pleasantly written by more than one author who we have 

 not been able to consult, and have no space to do more than indicate. 

 In later days Faraday, De la Rive, Roscoe, and many others have rendered 

 chemistry much more popular, while they have added to its treasures. The 

 story of the progress of chemistry would fill a large volume, and we have 

 regretfully to put aside the introduction and pass on. 



Before proceeding to investigate the elements, a few words concerning 

 the general terms used in chemistry will be beneficial to the reader. 

 If we look at the list of the elements, pp. 308-9, we shall see various 

 terminations. Some are apparently named from places, some from their 

 characteristics. Metals lately discovered by the spectroscope (and recently) 

 end in ium ; some end in " ine," some in " on." As far as possible in late 

 years a certain system of nomenclature has been adhered to, but the old 

 popular names have not been interfered with. 



When elements combine together in certain proportions of each they 



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