--the kissing of
hands, or of feet and toes, which still survives in Court
functions--whilst the Viennese and the Spaniards, though they no
longer actually carry out their threat, habitually startle a foreigner
by exclaiming--"I kiss your hands." The Russian Sclavs are the most
profuse and indiscriminate of European peoples in their kissing. I
have seen a Russian gentleman about to depart on a journey "devoured"
by the kisses of his relations and household retainers, male and
female. Among the poor in rural districts in Russia this excessive
habit of kissing leads to the propagation of the most terrible
ulcerative disease among innocent people--as related by Metchnikoff in
the lectures on modern hygiene which he gave in London some seven or
eight years ago (published by Heinemann).

We may take it, then, that the act of kissing is primarily and in its
remote origin an exploration by the sense of smell, which has either
lost its original significance, and become ceremonial, or has, even
though still appealing to the sense of smell, ceased to be (if,
indeed, it ever was so) consciously and deliberately an exercise of
that sense. This leads us to the very interesting subject of the sense
of smell in man and in other animals. There is no doubt that the sense
of smell is not so acute in man as it is in many of the higher
animals, and even in some of the lower forms, such as insects. It is
the fact that so far as we can trace its existence and function in
animals, the sense of smell is of prime importance as distinguishing
odours which are associated either with objects or conditions
favourable to the individual and its race, or, on the other hand,
hostile and injurious to it. It never reaches such an extended
development as a source of information or general relation of the
individual to its surroundings as do the senses of sight, hearing and
touch. It depends for its utility on the existence of odorous bodies
which are not very widely present, and are far from universal
accompaniments of natural objects. Apart from some pungent mineral
gases, all odorous bodies are of organic origin. Even as recognised by
the less acute olfactory sense of man, the number and variety of
agreeable and of disagreeable scents, produced by various species of
animals and plants, is very considerable. But there is no doubt that
the number and variety discriminated by such animals as dogs and many
of the other hairy, warm-blooded beasts is far gre