THE EFFECTS OF ACID AND ALKALINE SOLUTIONS 
UPON THE WATER RELATION AND THE 
METABOLISM OF PLANTS^ 
Alfred Dachnowski 
The problem of the physiological water requirement of plants (4) is 
essentially only a phase of that greater problem, — the quantity of 
water retained by living organisms, by cells and tissues, under a variety 
of normal and pathological conditions, or during development and the 
evolution of succulency (of fruits etc.) in the higher plants. It is 
clearly evident that an attempt to answer this question should also be a 
step toward an analysis of the ways and means by which tissues and 
cells hold their normal or abnormal amount of water, i. e., the forces 
which are active in the process of absorption and retention of water. 
Investigators of late years have sought the explanation of the 
variations in the amount of water absorbed and retained by plants, as 
well as by animals, in differences in osmotic pressure, and more recently 
a theory has been proposed to account for it on the basis of the variable 
''affinity" of colloids for water. The pages that follow concern them- 
selves with a consideration of a few experiments and with the inquiry 
whether the acceptance of the suggestion here advanced merely ne- 
cessitates a revision of explanations or whether it adds another to the 
forces already considered as active in the water relation of plants. 
A review in detail of the arguments which have been brought for 
and against the osmotic conception of water absorption by cells (8), or 
the one from the point of view of the state of colloids (7,17), seems out 
of place at this time, since these are questions which on the basis of the 
facts now available can not be decided as yet. Though probably over- 
rated, the two theories have contributed the experimental data upon 
which depends much of the fundamental progress of the physico- 
chemical physiology of organisms. 
The experiments detailed below have been made with the view 
toward establishing experimentally what importance, if any, hydro- 
lytic reactions may have in determining the amount of water absorbed 
and retained by plants during germination and growth. That the 
* Contribution from the Laboratory of Plant Physioiogy, Ohio State University. 
412 
