door with one key; with another key he may unlock his desk; with
another he may unlock a drawer in the desk; and then, having opened
his safe, he may use still another key to unlock his strong box. At
night he may look carefully to see that each of these things is again
carefully locked before he goes home. And so, we see, keys are for two
purposes--to unlock and to lock.

[Illustration: Fig. 11]

"Most keys are made of metal and are in our own keeping and subject to
our own will, but there is another key of which I shall speak, which
goes before many a man, working entirely independent of him. And as it
goes, it locks the doors which he wishes to enter, and it unlocks many
another door which he does not want to enter and forces him to go
through it. I will draw the picture of this key. [Starting at the
final stroke of the letter Y, continue the line, and ending with the
letters W-H-I-S. Then add the lines to complete Fig. 12.]

[Illustration: Fig. 12]

"Let us see for a moment what this key does. It locks the door to
health and opens the door to disease. Sir Andrew Clark, one of
England's greatest physicians, says: 'I am speaking solemnly and
carefully in the presence of truth, and I will tell you that I am
considerably within the mark when I say to you that, going the round
of my hospital wards today, _seven out of every ten_ owed their
ill-health to strong drink.'

"And again: This key bars and locks the way to good positions, where
men may earn the money needed to keep themselves and their families