"The strongest waters for the purpose, my lord, are those at Bad-Nauheim, in Germany, a pretty little village to the east of the Taunus Mountains, twenty-three miles north of Frankfort-on-the-Main. The next strongest are those of Royat, in the centre of France, although the wells of Spa, in Belgium, are about equal in strength to the French waters."
"What do you mean by strength, Ponderby? Salt, sulphur, or what?"
"There is a very large proportion of salt in the waters at each place, but the strength I referred to, which has proved so beneficial in cardiac troubles, is carbonic acid gas, held in solution by the waters of each district."
"Thank you, Ponderby."
Ponderby bowed, and vanished as silently as he had appeared.
"Well, Peter, there you are, with a choice of three nationalities, and of three charming health resorts. Which do you prefer?"
"I should say Nauheim. As it possesses the strongest waters, the cure would probably take the shortest time," replied the practical Mackeller.
"That appears reasonable; still, we'd better make sure."
He touched the bell once more.
