The reason is, answered I, that you make use neither of reflection nor of your imagination.
Ah! I recollect now, is it not a question about air? Unless there were a particular opening in the cane, I may suck in vain, no juice will come.
You have well explained the difficulty: but how will you manage to set it right?
Father, lend me your cane an instant.
No, no, that will not do; what I wish is, that you should yourself invent the remedy.
Let me see; I imagine that I have only to make a little opening just above the first knot, and then the air can enter.
Exactly right. But tell me what you think would be the operation of this opening near the first knot; and in what manner can it make the juice get into your mouth?
The pith of the cane being completely interrupted by each knot in its growth, the opening that I might make below, could have no effect upon the part above; in sucking the juice, I draw in my breath, and thus exhaust the air in my mouth; the external air presses at the same time through the hole I have made, and fills this void: the juice of the cane forms an obstacle to this effort, and is accordingly driven into my mouth. But how shall I manage, when I have sucked this part dry, to get at the part above?
Oh, ho! Mr. Philosopher, what should prevent you, who have been reasoning so well about the force and fluidity of the air, from immediately conceiving so simple a process as that of cutting away the part of the cane you have already sucked dry, and making a second perforation in the part above, so that.....
Oh, I have it, I have it, I understand;—but if we should become too expert in the art of drawing out the juice, I fear but few of the canes will reach our good friends in the tent.