242 
gaseous, though it would be difficult for 
him to comprehend their relations to one 
another. Air in motion makes itself felt, 
but of gaseous matter in general his knowl- 
edge would be very limited and vague. 
The simplest of tests would make him ac- 
quainted with elasticity, malleability and 
ductility, as well as with density and te- 
nacity ; fusibility and solubility would un- 
doubtedly greatly puzzle him, and he would 
of course remain ignorant of light, of sound 
and of the physical universe beyond his 
limited sphere. 
If to this being of one sense the so-called 
‘ chemical senses’ of taste and of smell were 
added, he would acquire greater insight into 
the special qualities of bodies that affect 
these organs; he would observe the agree- 
able odors of the natural products of the 
soil and forest as well as the offensive ones 
in the three kingdoms of nature; he would 
learn to differentiate many gases previously 
regarded as identical; he would learn to 
distinguish between alkaline and acid, 
sweet and bitter substances, and to recognize 
those having particular flavors. On the 
other hand, the intelligent being of three 
‘senses would fail to comprehend the physio- 
logical processes by which the sensations are 
perceived, and in this respect he would be 
little less ignorant than are beings of five 
senses. 
On endowing this imaginary person with 
the sense of hearing his knowledge of the 
external world would be greatly enlarged 
and his personal comfort increased, he would 
also acquire a more exact knowledge of 
some of the properties of matter; he would 
become conscious of vibrations in the air 
conveying sounds, and by listening to the 
roar of a Niagara or to the chirp of a cricket, 
to the melodies of song birds or to the fierce 
growl of a beast of prey, he would attain 
to more lofty ideas of the marvels of nature 
than in his deaf state. He could now learn 
of the crackling of brimstone, the ‘cry’ of 
SCIENCE. 
[N. S. Vou. XIII. No. 320. 
tin, the snapping of electric sparks, and the 
startling detonations caused by combustion 
of ‘villainous saltpetre’ and of certain gas- 
eous mixtures. 
If finally, the precious gift of sight should 
be bestowed upon the subject of four senses 
a new world would be opened to him, and 
his intellectual and emotional capacities 
would be enhanced immeasurably ; for the 
first time he would be able to realize the 
full meaning of the word beautiful as ap- 
plied to nature. With the fifth sense he 
would perceive the beauty of form, of color, 
of luster, of ornamentation in the flower, 
the bird, the insect, the floating clouds and 
in the rainbow; he would have opened to 
him the magnificent spectacle of a starry 
firmament, of an aurora and of the sun in 
its noon-day glory. He would now be fairly 
equipped for investigating physical science. 
At a remote period seven senses were at- 
tributed to man.; these are given by the 
Hebrew author of the ancient book Eccle- 
siasticus as seeing, hearing, tasting, feeling, 
smelling, understanding and speech. They 
are referred to by the poet Pope in the 
couplet: 
‘Good sense which only is the gift of Heaven, 
And though no science, fairly worth the seven,’’ 
and the idea survives in the singular phrase 
in common use: ‘ Frightened out of one’s 
seven senses.’ 
The nature of a sixth sense has been a 
matter of speculation, but it is hardly less 
difficult for individuals with five senses to 
form a conception of an extra sense, than 
it is for a sightless person to acquire any 
adequate idea of the true significance of 
seeing. The sixth sense has been called 
the muscular sense as distinguished from 
touch, but we prefer to think of it as a 
sense for cognizing forms of energy whose 
seat of action lies in the ether supposed to 
pervade space. 
While it is absolutely impossible for a 
finite mind to plan the structure of an or- 
