on the mucous membrane of the throat
and passages is fatal. So when the terms "fire-eating" or "fire-eater"
are used it will be in the sense of its being a theatrical act. There is
a trick about it, and the trick is this:

In the first place, the flame itself is produced by blazing alcohol.
This produces a blaze, and a hot one, too, but there is no smoke. In
other words, the combustion is almost perfect, there being no residue of
carbon to remain hot after the actual flame is extinguished.

And now as to the actual putting into one's mouth something that is
blazing hot: It all depends on a very simple principle.

If the hand be thoroughly wet in water it may be safely thrust for a
fraction of a second into a flaming gas jet. But mark this--for the
_fraction of a second only_. The water forms a protecting film for the
skin, and before it is evaporated the hand must be taken out of danger.
In other words, there is needed an appreciable time for the fire to beat
the skin to the burning point.

This immunity from burns, to which the professional fire-eaters owe
their success, comes from this film of moisture on their skin. They do
not always use water--in fact, this is only serviceable for a momentary
contact with flame, and, at that, on the hands or face. In case a longer
contact is desired, a fire-resisting chemical liquid is used.

It is about the contact of flame with the tender mucous membrane
surfaces of the mouth and throat that Joe, as a fire-eater, was most
concerned.

In the first place, there is a constant film of the secretion called
saliva always flowing in the mouth. It comes from glands in the throat
and mouth, and is very necessary to good digestion.

Now, for a very brief period this saliva, which is just the same as a
film of water on the hand, resists the fire. But professional
fire-eaters do not depend on saliva alone. They use a chemical solution,
and this is what Joe did when he drank something from a glass.

What that chemical solution was, Joe kept as a closely guarded
professional secret. He feared, too, that some boy might make it, rinse
his mouth out with it, and then, getting an audience of his chums
together, might try to eat some blazing coals. He might, and very likely
would, be severely burned, and his parents or those in charge of him
would blame Joe for allowing such dangerous information to leak out.

So, though he guarded all his secrets of magic, he was particularly
careful to