hour of the target practice; and the result of it all was the discovery that, in every instance, each man in each group did his quickest firing and his best hitting when he had had no alcohol whatever for two or three days

beforehand, and that he did his poorest work when he had used alcohol at any time within twenty-four hours.

As staff surgeon Mernetsch reports, "When under alcohol the result was thirty per cent less hits in quick fire, and the men always thought they were shooting faster, whilst actually they shot much more slowly. When slow aiming was allowed the difference even went to fifty per cent."

The same sort of testimony comes from Sir Frederick Treves of England. He says that "out of thirty thousand men who marched to the relief of Ladysmith, those who first fell out were not the fat or the lean, the short or the tall, the young or the old, but those who drank liquor." He says the drinkers on the march could not have been more plainly marked if they had had placards on their backs.

No doubt Emperor William of Germany has heard all this about the effect of alcohol on the living cell, for I am told that he allows no one to drive his automobiles who uses alcohol at any time. Clearly enough he wishes no hand on his machine that is less steady than it might be, no eye that is duller than it should be, and no wits that are less nimble than they need to be when emergencies arise.

The teaching of this chapter is that when such cells of the body as we have been studying about are reached by alcohol they are weakened and defeated, whereas when they are unreached by alcohol they are able to do their best work.

CHAPTER IX.

STRUCTURE OF THE NERVE MACHINE

If by any clever process we could separate the nerves of a man from the rest of his body, if we could turn each one of these nerves into something stiff and firm, and then could stand the entire group on a pedestal in precisely the shape which it had when it did its work in the body, this network of stiff nerves would be so delicate and so closely woven together that we should be able to follow perfectly the outline of the man to whom it belonged. We should know his height, the breadth of his shoulders, the size of head, hands, and feet; while, at the same time, we should note that on certain parts of his skin the network was finer and more intricate than on other parts.

If, going further, we should cut that nerve figure open, we should find other great clusters of nerves that showed the outline of every separate organ of the body.

Having seen all this, unless we know the facts of the case, we might give a thousand wild guesses as to what this wilderness of nerves was for and how it was ever able to control the sensations and the movements of a human being.

Before the microscope was invented even the wisest men were obliged to do much of their scientific work by guessing. They first im

agined that each nerve was a tube filled with something exceedingly fine and delicate, called animal spirits. The stuff, they said, was neither gas nor air, but something far more subtle than either. They thought that by means of this substance every nervous system did its feeling, moving, and thinking.

Later, other men supposed that the contents of the nerve tubes was something heavier than gas, and they called it nerve juice.

In recent times, however,

the microscope has done as

much for nerves as for mi- NERVES THAT SHOW THE OUTLINE crobes and the amoeba. It

OF THE HUMAN BODY

has destroyed numberless old-fashioned theories, and has shown that the entire nervous system is simply a construction of nerve cells and their longer and shorter

arms.

We ourselves are able to believe this at once; for our acquaintance with amoeba and amphioxus has shown us that each separate part of a living creature is a closely connected mass of cells, and that each part carries on its own particular line of business. In addition, however, nerve cells are seen to have special peculiarities of their own. The microscope shows that each one of these has armlike projections which resemble the arms of the amoeba, that they are sometimes very long, and that it is the countless millions of slender arms from countless millions of nerve cells that give us our nerves.

Scientists tell us that every white nerve is a bundle of nerve fibers, each one of which is neatly and snugly wrapped by a fatty covering that makes it look white; and that the difference between large nerves and small nerves is quite the same as the difference between large bundles of telephone wires and small bundles of wires, for in each the number of separate strands explains the size.

Since we know so much about the amoeba, we are ready to understand at once that each separate fiber in the bundles is the long arm of some cell at a distance from it, and that the arm of the nerve cell is as truly a part of the cell itself as the arm of an amoeba is part of the amoeba. Moreover-and this is quite an important point—the substance of the nerve cell, arm and all, is similar to that of the amoeba. Both are protoplasm.