SYNTHETIC WORK IN CARBOHYDRATES 331 



There are only four alcohol and acid isomers for the eight 

 sugar isomers in this group. In the other higher sugar groups 

 the conditions are somewhat changed. But by studying the 

 results of oxidation or reduction on sugars, it may be shown 

 that the compounds so obtained point to the probable con- 

 figuration of a given sugar; and in this way, these formulae 

 express the conclusions of actual experiment. 



These active asymmetrical compounds are obtained directly 

 from natural products, or are derived from optically active 

 compounds. If compounds are formed from inactive ones, 

 and inactive modifications arise, these inactive forms must 

 be decomposed in order that the active form may appear. 



Although these active compounds are the resultants of 

 accompanying life processes, they are not regarded by the 

 chemical thinkers of the day as essentially due to a life force. 

 Fischer believes that these active compounds will all be made 

 synthetically. This is by no means assuming that the know- 

 ledge to fabricate these active substances will give into the 

 hands of the chemist the secret touch to set these molecules 

 into a life mechanism. 



The example of the glorious period of the highest achieve- 

 ments in Greek art remains as a reminder that neither the 

 skill of a Phidias nor of a Praxiteles could give to their creations 

 the breath of life. The analogous height and limit of relative 

 perfection in attainment is seen in other developments of hu- 

 man conception. Each later development may reach a higher 

 round of the ladder than its predecessors, and the standpoint 

 of vision may be a line nearer that goal which seems to recede 

 as the effort of advance reaches forward. 



An Arabian alchemist, it is said, first obtained grape sugar, 

 or glucose, in a solid form, by concentrating grape sap. It was 

 obtained pure by the chemist Marggraf, in the middle of the 

 last century. The conversion of starch into grape sugar by 

 boiling with dilute acids was discovered by Kirchhoff, in 1811. 

 No less interesting is the recent work of Rohmann, wherein 

 he shows that blood serum converts potato starch into dextro- 

 glucose, and that finally, at the end of the reaction, maltose, 

 likewise soluble starch and dextrine, remain. 



