His solution made him famous: Fehling's test

Bread and soap: Fehling's other chemical research

Even though his name is now synonymous with his test, determining the amount of sugar in solutions wasn't Fehling's only achievement. As a pupil of Liebig he first focussed his attention on organic chemistry, Liebig's field, and in his first years in Stuttgart he investigated various substances based on Liebig's theory and method. Yet through his work at the Polytechnical School and his additional posts, his interest increasingly shifted to a wide range of agricultural and industrial issues. Fehling dealt with highly practical questions of commercial life in a vast range of studies, the empirical work for which he often had his pupils do.

• His first years in Stuttgart gave rise to a very modern-sounding question: Fehling was looking for ways of making textiles waterproof without making them impermeable to air - he was searching for a water-resistant breathable membrane.
• In 1851 Fehling returned home from a trip to England with the idea of using a soap solution to determine the hardness of water, a method already in practice in England. On his return he had his assistant Andreas Faißt conduct experiments with soap solutions in the hope of solving this problem. These studies led to what is now the "German water hardness scale" used to this day.
• In the mid-1850s Fehling studied the water content of bread, weight loss during bread baking and the possibilities of using bran to bake bread. Since the years of food shortages in the 1840s, this had been more than a mere academic matter ...