"One who faints is dead if he does not I come to,' and nothing is more
likely than that too susceptible lovers have actually gone off in this
way. Everything depends on how the heart behaves itself in these
and similar trying moments. The mechanism of its actions becomes an
interesting subject, therefore, to lovers of both sexes, and to all who
are capable of intense emotions.

"The heart is a great reservoir, which distributes food, drink, air, and
heat to every part of the system, in exchange for its waste material. It
knocks at the gate of every organ seventy or eighty times in a minute,
calling upon it to receive its supplies and unload its refuse. Between
it and the brain there is the closest relation. The emotions, which act
upon it as we have seen, govern it by a mechanism only of late years
thoroughly understood. This mechanism can be made plain enough to the
reader who is not afraid to believe that he can understand it.

"The brain, as all know, is the seat of ideas, emotions, volition. It is
the great central telegraphic station with which many lesser centres are
in close relation, from which they receive, and to which they transmit,
their messages. The heart has its own little brains, so to speak,--small
collections of nervous substance which govern its rhythmical motions
under ordinary conditions. But these lesser nervous centres are to a
large extent dominated by influences transmitted from certain groups of
nerve-cells in the brain and its immediate dependencies.

"There are two among the special groups of nerve-cells which produce
directly opposite effects. One of these has the power of accelerating
the action of the heart, while the other has the power of retarding or
arresting this action. One acts as the spur, the other as the bridle.
According as one or the other predominates, the action of the heart
will be stimulated or restrained. Among the great modern discoveries in
physiology is that of the existence of a distinct centre of inhibition,
as the restraining influence over the heart is called.

"The centre of inhibition plays a terrible part in the history of
cowardice and of unsuccessful love. No man can be brave without blood
to sustain his courage, any more than he can think, as the German
materialist says, not absurdly, without phosphorus. The fainting
lover must recover his circulation, or his lady will lend him her
smelling-salts and take a gallant with blood in his cheeks. Porphyro got
ov