THE FIVE SENSES 9 
With insects generally the sense of smell is extremely 
acute, as all entomologists agree in telling us; and 
although Sir John Lubbock’s well-known experiments 
proved beyond question that insects see colours, and 
prefer blue to red, and red to yellow, yet it remains 
true that insects rely mainly on odour in their search 
fanetood ‘or. for each other. The sense of smell is 
perhaps of all our senses that least under our own con- 
trol. It is of all other senses the most subtle, and most 
difficult to regulate, or measure (see p. I0), or define. 
We may to some extent actually avoid touching, seeing, 
or tasting, but, alas! our ears and our noses cannot 
often be preserved from the disagreeable sounds or 
odours that surround us. All the senses are mnemonic, 
but none are so potent in recalling persons, scenes, 
or places as is the sense of smell. Sound may be 
analysed and set down as in music; colour is simplified 
and can be arranged in methodical form; but, despite 
the crude attempt of the late Dr 5S. Piesse in his “ Art 
of Perfumery,” it yet remains for some specialist in 
odours to give us a gamut or scale, so to speak, of the 
thousand and one subtle whiffs of fragrance, or the 
myriads of odour waves that so often bombard the 
delicate nerve centres that lie under the mucous mem- 
brane inside our noses. Children are often taught that 
it is rude to smell their food before eating it, and yet 
there are times when the primitive nose test might save 
them and ourselves from many dietetic troubles. Experts 
in selecting the best solid and liquid food products, use 
their noses as well as their eyes with the best results, 
and the subtle art of smell and power of diagnosing 
things by nose power is well worth developing to its 
fullest extent. 
(4) Sight.—It is a sad thing to lose one’s sight, and 
yet the blind have many compensations; and it is a 
well-known fact that, other things being equal, the 
