s too obvious to need pointing out. When the
machine is used to decompose water, the heat of the muscle, like that
of the battery, is consumed in molecular work, being fully restored
when the gases recombine. As before, also, the transmuted heat of
the muscles may be bottled up, carried to the polar regions, and there
restored to its pristine form.

*****

The matter of the human body is the same as that of the world around
us; and here we find the forces of the human body identical with those
of inorganic nature. Just as little as the Voltaic battery is the
animal body a creator of force. It is an apparatus exquisite and
effectual beyond all others in transforming and distributing the
energy with which it is supplied, but it possesses no creative power.
Compared with the notions previously entertained regarding the play of
'Vital force' this is a great result. The problem of vital dynamics
has been described by a competent authority as 'the grandest of all.'
I subscribe to this opinion, and honour correspondingly the man who
first successfully grappled with the problem. He was no pope, in the
sense of being infallible, but he was a man of genius whose work will
be held in honour as long as science endures I have already named him
in connection with our illustrious countryman Dr. Joule. Other
eminent men took up this subject subsequently and independently, but
all that has been done hitherto enhances instead of diminishing the
merits of Dr. Mayer.

Consider the vigour of his reasoning. 'Beyond the power of generating
internal heat, the animal organism can generate heat external to
itself. A blacksmith by hammering can warm a nail, and a savage by
friction can heat wood to its point of ignition. Unless, then, we
abandon the physiological axiom that the animal body cannot create
heat out of nothing, we are driven to the conclusion that it is the
total heat, within and without, that ought to be regarded as the real
calorific effect of the oxidation within the body.' Mayer, however,
not only states the principle, but illustrates numerically the
transfer of muscular heat to external space. A bowler who imparts a
velocity of 30 feet to an 8-lb. ball consumes in the act 0.1 of a
grain of carbon. The heat of the muscle is here distributed over the
track of the ball, being developed there by mechanical friction. A
man weighing 150 lbs. consumes in lifting his own body to a height of
8 feet the heat of a grain