MICHIGAN ACADEMY OF SCIENCE. 
55 
was to use dry filter paper. When the lower end of the tube was immersed 
in water, the water began to climb, and the highest point reached by the 
water was clearly indicated by the color — the wet appearance — of the filter 
paper. An interesting point was brought out with filter paper first made 
blue with litmus, and a weak solution of sulphuric acid used as the capillary 
liquid. The acid showed clearly its height at any given time by the red- 
dening of the filter paper, but at the same time it could be readily seen that 
the acid and the water had separated in ascending — the water rising faster 
than the acid. 
The application of the^e separation phenomena has been thoroughly 
worked out by Frederick Goppelsroder, Basel, 1901. His work is exhaustive 
and is entitled Capillaranalyse Emporsteigen der Farbstoffe in den Pflanzen. 
Though Goppelsroder used some form of cellulose in his separation analyses, 
yet he did not determine for any one of his liquids or substances in solution 
the actual amount of capillary attraction. 
