102-(72) PHYSIOLOGIGAL STCOTrFICATS'CE OF VITAL FOECE. 



atomic motion, which furnishes the most perfect expla- 

 nation of chemical reaction. 



Of the highly complex series of albuminoid substances, 

 which neither crystallize nor possess any combining 

 equivalent, and therefore can not be expressed by 

 exact symbols, analytic chemistry knows but little, 

 and hence it would be in vain to attempt at pres- 

 ent their reproduction by synthesis. .Notwithstanding 

 our ignorance of essential facts, the progress of synthetic 

 chemistry has been great, and the prospect is favorable 

 for more brilliant achievements in the future. 



YVohler, in 1828, first, by synthesis, formed urea from 

 ammonia cyanate. It was claimed by the critics that 

 urea, being a nitrogenous metabolite, a product of ani- 

 mal decomposition, was a mineral, ra ther than an element 

 of the animal tissues, but when Fownes, in 1841, pre- 

 pared cyanogen itself direct from its elements, and from 

 this salt, urea, the fact was recognized and accepted, al- 

 though it was affirmed that a "vital force 1 ' was neces- 

 sary to account for the more complicated organic com- 

 pounds, of which series urea was a member having only 

 simple combinations. This was disproved by Berthelot 

 in 1856, when lie obtained the potassium salt of formic 

 acid. Then followed the production of acetylene, 

 marsh gas. ethylene and other hydrocarbons from 

 inorganic materials. Marsh gas was converted into 

 methyl alcohol ; and ethylene, into ethyl alcohol, and 

 from these alcohols, formic and acetic acids were made. 

 Startling as these results were, the substances formed 

 were, relatively, simple in nature, and the tl vital force" 

 still ruled in the more complicated bodies of organic 

 origin. 



Synthetic work continued to achieve brilliant results 

 and added to its list of vegetable compounds — oxalic, 

 valeric, malic, citric, tartaric and salicylic acids, the 

 oils of garlic, mustard and wintergreen, also conine, ali- 

 zarine and indigo. 



Of animal compounds, leuciri, kreatin, sarcosin and 

 taurin are added to the large and growing list of sub- 

 stances from which analysis and synthesis have banished 

 the vital force and harmonized the facts of their exist- 

 ence with the physical and chemical forces of the inor- 

 ganic world. 



