285 



uiic compound with an excess of the laevogyrate component '). 

 while 1. 11 lot and Raper-) find it more closely related to a 

 dextro -yrate ribose, than to a racemic arabinose, as Neuberg 

 thinks it to be. 



From this the impression is left that, notwithstanding the 

 enormous development of organic synthesis since the days of 

 I i < b i g and W 6 h 1 e r, there still remains a deep gulf between 

 natural and artificial synthesis. The plant, that mysterious and 

 highly complicated laboratory, produces from the simple in;t 

 constituents of the atmosphere and the soil, within a very limited 

 range of low temperatures moreover, the necessary carbohydrates, 

 proteids, etc., in their optically active forms. 



"I know of no more profound difference than this between common 

 substances and those produced under the influence of life", - 

 Pasteur wrote again in 1860; and apparently he was quite 

 justified. 



Natural, in contrast to artificial synthesis, thus appears to be 

 a strictly "one-sided" or "asymmetrical" synthesis, and moreover 

 of a very exclusive nature too. All attempts to isolate laevogyratory 

 glucose or fructose horn plants, have hitherto failed 3 ), neither has 

 there been any success with any of the other optically active 

 products of vegetable or animal bodies. A living world, the 

 mirror-image of the one known to us, seems to be a grotesque 

 phantasy. What would be the consequences of an eventual sudden 

 inversion of all synthesis in plants and animals, as we now know 

 it ? "What world would be presented to our eyes", - - asks 

 Pasteur, - "if the cellulose turned from a right-handed to 

 a left-handed, the blood-albumine from a laevogyrate to a dextro- 

 gyrate substance?" Indeed, if such circumstances could be realised 

 in the living tissues, investigations of unlimited range would be 

 open to the future, and at present such questions, are worthy 

 of the most careful attention of scientists. However, so far, we 

 can only state the rigorous and remarkable constancy of character 

 of the chemical world in plants and animals. The living world 

 is "specific" in its dissymmetry, and its dissymmetrical specificity is 



1) K. O. af Klercker, Deutsches Archiv. f. Klin. Medizin, 81. 284. (1912). 

 Cf. also: R. Luzzatto, Archiv. f. exper. Pathol. und Pharmokol., Suppl. Hml. 

 (1908), p. 366. 



2) J. H. Elliot and H. S. Raper, Journ. Iliol. Chem. II. 211. (1912). 



3) E. Fischer, Ber. d. d. Chem. Ges. 27. 3230. (1894). 



