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certainly liad not sliown to be the accumulation or transmission 
of some occult transformation of heat. We simply observe 
that according to Tyndall and Mayer and all the scientific 
world, a special function is accorded to the nerves — over and 
above any which the correlation of forces can illustrate, under 
mechanical law in the machine or chemical decomposition in the 
battery — and this is a function of directing — i.e. of liberating 
and detaining muscular force — which is illustrated by lifting a 
valve, or pulling a trigger. It were far better illustrated, as it 
seems to our unsophisticated minds, by the power of a band or 
gearing to carry motion in a machine, or of wire to transfer 
potential motion or potential heat in a battery. It is very evi- 
dent that when Prof. Tyndall began his argument which was to 
prove that “ the body falls under the category of machines,” 
and that as a machine it genei’ates no force, he does not seem to 
have thought of any other function as possible except the two, 
of generating or transforming force. Not seeing that his animal 
body, his homvie mach ine , does through the nerves perform the 
additional function of directing or transferring force, that is of 
determining when and where it should act, it is not surprising 
that he meets this indefinitely conceived demand by the con- 
venient image or picture of a valve, a detent in a machine or a 
trigger in a musket. He ought to have bethought himself, and 
corrected the premises of his disjunctive, and instead of assert- 
ing, the animal body either creates force or transforms force, ho 
should have said, the human body either creates force or trans- 
forms force or also directs force. Then in order to prove that it 
is a machine, he must prove that it directs force through the 
nerves, by either mechanical or chemical agency. This last he 
does not attempt to do. He does indeed assume that nerve 
substance is wasted by use, and implies that heat is probably 
evolved in nerve activity, and illustrates this by a rod of anti- 
mony rendered sensitive by electi’olysis as it carries forward 
heat and smoke from one end to another. From this he would 
doubtless leave us to infer that the nerves like the muscles 
never act, except under the general conditions of correlation. 
But in all this there is not the slightest attempt to explain by 
what mechanical process the nerves direct or transfer motion. 
He does indeed tell a somewhat long story about experiments 
which show that the process of movement or affection in the 
nerves, sensor and motor, to and from the brain, requires an 
appreciable lapse of time, so that a second must elapse before 
a whale seventy feet long would feel a wound in his tail, but 
he is sublimely unconscious of the fact that the new function of 
shifting motion, by valve, detent, or trigger during this second, 
makes the machine a little more complicated than ho had at 
