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VOLUME XXXII eile NUMBER 4 
BOTANICAL .GAZear 
OCTOBER, roor 
THE APPLICATION OF NORMAL SOLUTIONS TO 
BIOLOGICAL PROBLEMS. 
JAMES B. DANDENO. 
Jupcinc from recent investigations into the effects of ions 
upon plant and animal life, one is led to conclude that there is 
much confusion in regard to the interpretation of certain stand- 
ard chemical solutions. It is not to be doubted that solutions 
have a very important part in biological functions, and because 
of their importance it is deemed advisable to attempt to place 
this branch of an important subject upon a firmer basis. 
Since solutions of molecular concentration have been adopted 
for comparison, in place of the older percentage concentration 
solutions, there seems to be a great tendency to misinterpretation 
and confusion. Solutions prepared on the percentage basis are 
not now considered scientifically accurate when used for pur- 
poses of comparison, while those molecularly equivalent may be 
compared with scientific accuracy. The molecular and the 
equivalent solutions are the only ones here discussed. 
Much of the physiological work done with molecular solu- 
tions proves upon examination to be faulty because of a miscon- 
ception of the meaning of xormal solutions, gram-equivalent per 
liter solutions, and gram-molecule per liter solutions. There are 
no less than three interpretations of what a normal solution is. 
One takes it to be a gram-molecule per liter of solution. Another 
takes it to be a gram-equivalent per liter of solution. Still another 
regards it as a gram-molecule or a gram-equivalent per liter of 
229 
