ANNUAL ADDRESS OF THE PRESIDENT. XXXIX 
plants some of this passing matter becomes fixed for a time, but 
eventually returns from the biotic to the mineral kingdom. Among 
animals this passage of physical matter through the biotic form is 
more rapid. The organic functions, also, of these bodies are but 
arranged or organized motions. Life is motion—the specific motion 
called function. 
Again, among the aggregations of the physical kingdom, stellar 
systems are aggregates by virtue of motion. The combination ob- 
served is due to composed motion. Of the mechanical combina- 
tions, that exhibited in the atmosphere is such by virtue of motion— 
that is, the gaseous state is preserved by the interference of molecu- ° 
lar motions, and the bodies into which it is imperfectly differen- 
tiated, 7. ¢., currents of air, are such by virtue of motion. Again, 
the imperfectly aggfegated bodies of water are such by virtue of 
motion. This is seen to be true of the clouds floating in the air, 
and of rivers rolling to the seas. Lakes with outlets are bodies of 
water in motion, forever fed from the clouds, forever discharging 
into the sea; and mediterranean seas without outlet are perpetually 
receiving and discharging their waters; and so far as the sea is 
differentiated into currents, these are bodies imperfectly aggregated 
by motion. 
There yet remain certain molecular combinations of inorganic 
substances, due to affinity and gravity, the nature of which is not 
so immediately perceived. Now, as all societies and other anthropic 
combinations are such by virtue of their motions, known as activi- 
ties, and as all biotic bodies are such by virtue of their functions, 
and as all stellar combinations are such by virtue of stellar motion, 
and as finally all mechanical combinations are such by virtue of 
motion, it is at once suggested as an inductive hypothesis that those 
combinations the nature of which is yet unknown are also such by 
virtue of motion. It is an hypothesis worthy of consideration, that 
affinity and gravity are also due to motion. It has even been sup- 
posed by some that chemical and barologic methods of combination 
are but diverse modes of the same process; that affinity and gravity 
constitute but one method of combination, and that we call it 
affinity when the combination involves minute bodies, below our 
sense perceptions, and gravity when larger bodies are involved. 
An attempt has thus been made to define the three kingdoms of 
matter in terms of matter and motion, showing that there are three 
