BIOPHYSICS AS A POINT OF VIEW IN PLANT PHYSIOLOGY ' 
Howard E. Pulling 
(Received for publication May 14, 1921) 
This year is the 300th anniversary of the appearance of Francis Bacon's 
"Novum Organum, or true suggestions for the interpretation of Nature." 
It is appropriate and perhaps not presumptuous to take as a text one of 
Bacon's remarks and as a subject a point of view with respect to our science, 
for Bacon's work was essentially the presentation of a point of view : "Francis 
of Verulam thought thus," he said. This text and this subject are contained 
in his 36th Aphorism: 
We have but one simple method of delivering our sentiments, namely, we must bring 
men to particulars and their regular series and order. 
In other words, it is proposed that we consider the appHcabihty of a 
quantitative, physical method to plant physiology: the regularity — the 
mathematical regularity — of the series and order of its "particulars." 
This applicability, indeed, is implied in the original meaning of the Greek 
word for physics: a knowledge of the regular successions and relations of 
events, whether these events be mechanical or vital. It is the Greek 
equivalent for the Latin word for nature, so that biophysics is but the re- 
charting of a field of knowledge, the traverse survey of which was made by 
the ancients. 
Whatever one may feel regarding the utility of a purely physical point 
of view in plant physiology, its chief value lies in its offering another gate- 
way into the unknown while closing none now existing, for the most securely 
based hope of progress in plant physiology rests upon the varied attitude of 
its votaries toward their science, a science that is unable to demand a 
particular viewpoint from the very nature of its subject matter. Like 
Bacon, I seek not to discredit the constituted authorities, or their methods, 
or their desires. But I do propose to call attention to certain possibilities 
that are not presented in the diet of reading that is regularly offered to 
those who are completing their apprenticeship as plant physiologists. 
The physical edifice is three-storied, at least in practice. The first 
story, on which the others rest, is the conspicuous one to the outsider. 
It is the busy, experimental floor that is presided over by Precision and is 
so commonly pictured in the textbooks. 
In the second story we find the models that serve to identify all physical 
processes regardless of where they may be encountered. With them is 
arranged the coirection of laws, theories, and hypotheses that is constantly 
^ Invitation paper read before the Physiological Section of the Botanical Society of 
America, in the symposium on biophysics, at Chicago, December 28, 1920. 
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