tion and renewal of these external influences that life and motion are 

 maintained." 



(Agriculture and Physiology, pp. 389-90.) 



When Liebig wrote thus he was perfectly well aware of the artificial 

 production of urea by his fellow investigator, Woehler in 1828, and 

 therefore could not have thought that that discovery was antagonistic to 

 his theory of the influence of the vital principle. Gmelin, the author of 

 the great hand-book of Chemistry, had in 181 7 maintained that organic 

 compounds cannot, like in-organic compounds, be artificially built up 

 from their elements, and Berzelius also enforced this distinction, 

 asserting that while in-organic bodies could, organic bodies could not 

 be artificially produced. Woehler's discovery and others of a like nature 

 since, have gone to prove that this was too sweeping an assumption. 

 Many organic bodies have been produced artificially but by means 

 and from substances altogether different from those employed in nature. 

 Take the production of urea by Woehler. He obtained it by heating 

 a solution of cyanale of ammonia. But that substance was produced, 

 by decomposing the potash salt, and the latter from fusing yellow 

 prussiale of potash and caustic potash with red lead. All of 

 these substances are foreign to food and organic life and most of them 

 are of a highly poisonous character. No wonder then that Liebig took 

 no notice of such discoveries as invalidating in the slightest degree his 

 contention that Life modifies and controls chemical affinities. He 

 knew very well that chemists would never be able to produce an organic 

 cell or a starch granule, and we know that, since his time every attempt 

 to produce urea by the oxidation of the albumenoids has failed. And 

 even although it should be found possible in the distant future, to 

 fabricate, let us say, some grains of sugar in a roundabout way from 

 strange artificial materials and with the help of complicated apparatus, 

 would it be reasonable to consider that as equivalent to its production 

 from the carbonic acid of the atmosphere in the tissues of the sugar 

 cane? I trow not. Nevertheless we have chemical authorities of high 

 reputation expressing themselves in the following way. " At the present 

 day the belief in a special vital force has ceased to encumber scientific 

 progress. We now know that the same laws of combination regulate the 

 formation of chemical compounds both in animate and inanimate 



