110 TRANSACTIONS OF THE [mAR. 21, 



workers in chemical science were practitioners of the healing- art, 

 either as pharmacists or as physicians. Stahl was a ph3='sieian, 

 Boerhaave was a physician, Scheele was an apothecary, Liebig an 

 apothecary's apprentice ; and you must also remember that all 

 these men worked for the love of the science, and without any idea 

 of the utility of their labors. Who can estimate the value of the 

 discovery of chloroform and chloral? yet Liebig had no idea of 

 making them useful when he discovered them. But this was the 

 beginning of a new era in organic chemistry, and discovery followed 

 discovery in such rapid succession that the disciples of the vital- 

 force theory were obliged to give way to the cloud of witnesses 

 taken from experimental chemistry proving the fallacy of their 

 theories. 



While Scheele, Bergman and Rouelle, and others were working 

 experimentally upon organic substances, Lavoisier, the Frenchman, 

 was watching their work, and, in connection with his experiments 

 upon oxygen and combustion, was paving the rough and rocky road 

 that led to modern researches. He it was who first proved how few 

 of the elements enter into the constitution of organic substances; 

 and, in the year 1793, he points out that while in the mineral king- 

 dom a large number of elements enter into the constitution of sub- 

 stances, in the animal kingdom we have generally only carbon and 

 hydrogen, and sometiiues nitrogen and phosphorus. It is rather 

 curious to note how near he was to the truth, with his limited 

 knowledge of the elementary composition of organic bodies, for 

 to-day we say that organic compounds contain, as a rule, only car- 

 bon, hydrogen, oxygen, nitrogen, and sulphur. Lavoisier had an 

 idea that oxygen was confined to the mineral kingdom, and his 

 methods of research had not taken into consideration animal pro- 

 du -ts, like albumen, which contain sulphur. Nevertheless, he was 

 the first chemist that saw clearly the special functions of carbon in 

 the constitution of organic compounds. 



Berzelius improved the methods of ultimate organic analysis, and 

 by his indefatigable energy as an analyst made us better acquainted 

 with a vast number of chemical compounds and their constituents; 

 but he firmly believed that the es.sential elements of organic com- 

 pounds were carbon, hydrogen, and nitrogen. Then came the dis- 

 covery by Gay Lussac of the compound radicle cyanogen, which 

 caused quite a flutter in the chemical world; but it was ultimately 

 believed that this was really an inorganic rather than an organic 

 compound ; and Leopold Gmelin, in his great " Handbuch" in 1817, 

 states that the difference between organic and inorganic bodies con- 

 sists in the fact that the inorganic compounds can be prepared arti- 

 ficially from their elements, while the organic compounds cannot, 

 and about the same time Berzelius enforced the statement by a 

 sentence in the introduction to his "Treatise." He says: "In 

 living nature the elements appear to obey very different laws from 

 those in inorganic nature; the products which result from the action 



