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. 
