BIOLOGY: H. F. OSBORN 
9 
Physico-chemical actions and reactions, which, so far as known, 
follow the laws of conservation of energy, are the chief phenomena 
observed in modern physiology, as set forth in such works as Loeb's 
"Dynamics of Living Matter." Through catalysis many of the actions 
and reactions are known to send off chemical messengers which are among 
the chief means of interaction in different parts of the organism. There 
are in animals other means of interaction, such as the enzymes, the 
secretions of the duct glands, the internal secretions of the ductless 
glands, and the nervous system. These interactions do not follow the 
laws of conservation of energy; they work at a distance, and the effects 
do not balance the causes. Certain phenomena of interaction, in which 
chemical messengers of various kinds coordinate the actions and re- 
actions of the organism, are now understood both in physiology and 
pathology as coordinating, correlating, accelerating (hormones), and 
retarding (chalones), as well as balancing growth and development. 
The nature of the actions, reactions, and interactions between the 
physical environment, the development organism, and the life environ- 
ment are relatively well understood. It remains to be determined what 
relations these actions, reactions, and interactions respectively have to 
the physico-chemical processes in the somatic and in the germinal chro- 
matin. There are some grounds for the hypothesis of Cunningham that 
some of these chemical messengers affect in a similar manner the germinal 
and bodily chromatin, but this subject is very obscure at present. 
■'• I am indebted to my colleague M. I. Pupin for valuable suggestions in formulating the 
physical aspect of these principles. He regards Newton's third law as the foundation not 
only of modern dynamics ill the Newtonian sense but in the most general sense, including 
biological phenomena. The second law of thermodynamics started from a new principle, 
that of Carnot, which apparently had no direct connection with Newton's third law of motion. 
This second law, however, in its most general form cannot be fully interpreted except by 
statistical dynamics, which is a modern oSshoot of Newtonian dynamics. With regard 
to the first law of thermodynamics, it is a particular form of the principle of conservation 
of energy as applied to heat energy. Helmholtz, who first stated the principle of conserva- 
tion of energy, derived it from Newtonian dynamics. 
^ "I. Every body perseveres in its state of rest, or of uniform motion in a right line, 
unless it is compelled to change that state by forces impressed thereon." 
"II. The alteration of motion is ever proportional to the motive force impressed; and 
is made in the direction of the right Hne in which that force is impressed." 
'TIL To every action there is always opposed an equal reaction: or the mutual actions 
of two bodies upon each other are always equal, and directed to contrary parts." 
"Newton's Principia; the Mathematical Principles of Natural Philosophy, by Sir Isaac 
Newton," translated into English by Andrew Motte, publ. Daniel Abbe, New York, 1848, 
pp. 83-84. 
