1921] EMERSON—BOG PLANTS 369 
significant results are shown in figs. 9-11. Distilled water was 
used throughout the experiment for watering the seedlings and 
maintaining the water level. This distilled water had a reaction of 
approximately 1 (neutral), although in some cases it showed a 
slight trace of acidity from carbonic acid. All the peat maintained 
Fic 8.—Growing boxes used in experimental work: fig. 7, growing box with 
Sit nda side facing camera (removable sheet iron false side is in place covering 
glass); fig. 8, growing box similar to that in = 7 placed in pan containing water, 
thus maintaining fixed water level in growing box 
a specific acidity of 3 throughout the experiment. The garden 
soils varied from specific reaction 1 to specific alkalinity 10. This 
last reaction was reached near the end of the experiment in the wet 
garden soil. The experiment was carried on for about two months 
during February, March, and April, 1921, in the cool room of the 
greenhouse. At the end of this period the plants were removed 
