116 ILLINOIS ACADEMY OF SCIENCE 
known to conceive a new thought, and then pass through a 
period of excitement as the consequences of the new discovery 
are considered. 
The conscious being can impart his thought to others, by 
methods wholly different from those by means of which it 
was imparted to him. In some mysterious way he gives direc- 
tive motion to a complex structure forming part of his habita- 
tion. The thought is expressed in words. 
A dog can express his displeasure, and declare war. Dogs of 
all nations express themselves in the same language when they 
defy an enemy. 
We have all heard the courteous call which the lord of the 
poultry yard issues to his many wives, when he discovers some 
delicious morsel of food. 
We are not surprised at the clatter and roar of moving ma- 
chinery or the clang of the blacksmith’s hammer. Is it not 
wonderful that the slow movement of our vocal organs, com- 
posed of soft and yielding tissues, can produce the sounds of 
articulate speech? When the air is practically all expelled from 
the lungs, slight motions of the flexible structures of mouth and 
throat can impart to the air a complex and wonderfully modu- 
lated system of waves, which carry a thought. 
These waves are in a general way alike for all persons who 
repeat the same message. But they have also modifications, 
peculiar to the structure and form of John Doe’s vocal organs. 
When these waves reach the ear-drum at the receiving station, 
vibrations representing all of these general and personal peculi- 
arities of the air waves, are produced in tissues connected with 
the brain of Richard Roe. He may be able to recognize a famil- 
iar voice. In addition he may learn that his friend has a cold. 
The voice may be that of a stranger, and yet he may be able 
to decide whether or not this stranger is an Englishman, a 
Scotchman or an Irishman. He might also obtain evidence 
that the speaker was either an American-German, or a German- 
American. In addition the thought which was conceived by 
John Doe is now in his possession. 
Later he may receive other thoughts. He may for a time 
become unconscious of the fact that the earlier thought is still 
with him. The muscular and nervous vibrations aroused by the 
