884 TRANSACTIONS OF SECTION K. 



Section K.— BOTANY. 

 I Presipent of the Section.— F. F. Blackman, M.A., D.Sc, F.R.S. 



THURSDAY, SEPTEMBER 3. 

 The President delivered the followingr Address : — 



'o 



The Manifestations of the Principles of Chemical Mechanics in the 



Living Plant, 



The UNiroKMiTY of Natuee. 



Among the phenomena of nature Man finds himself to be one ot medium mag- 

 nitude, for while his dimensions are about a billion times as great as those of 

 the smallest atoms that compose him they are also about one billionth part of his 

 distance from the centre of his solar system. 



From the vantage point of this medium magnitude the man of science scans 

 eagerly the whole range of natural phenomena accessible to him with a strenuous 

 desire for unity and simplification. 



By the unwearying study of special sections of this long front of natural 

 phenomena special guiding principles have been detected at work locally. No 

 sooner has this been accomplished than, in obedience to this desire for con- 

 tinuity througliout, such principles have been freely extended on either side 

 from the point of discovery. 



Thus, the theory of probability, which dealt at first with so limited an 

 occupation as drawing white and black balls out of an opaque bag, now is known 

 as the only determinable factor in such remote things as the distribution of the 

 duration of human lives and the effect of concentration of the colliding molecules 

 in a solutionupon the rate of their chemical change. Again, the principle of evolu- 

 tion discovered among living things has been extended, till to speak of the evolution 

 of societies, of solar systems, or of chemical elements is now but commonplace. 



The biologist, with all his special difficulties, has at least the limitation that 

 he is only concerned with the middle I'ange of the interminable hostile front of 

 natural phenomena, and that for him is ordained the stubborn direct attack, 

 leaving the brilliant attempts at outflanking movements to the astronomers on 

 the one wing and the workers at corpuscular emanations on the other. 



The atoms and molecules that the biologist has to deal with do not differ 

 from those passing by the same names in the laboratories of chemistry and physics 

 (at least no one suggests this), and their study may therefore be left to others. 

 At the other end of the scale, with astronomical magnitudes we have not to deal, 

 unless indeed we yield to the popular clamour to take over the canals on Mars as 

 phenomena necessarily of biological causation. 



In the study of that particular range of phenomena which is the special 

 allotment of the physiologists, animal and vegetable, we have had ever before ua 



