d. In the year 1698 some of it penetrated through the soil, and
the phenomenon was witnessed by many people, who believed it to be a
miracle. The church which was thereupon erected is still a well-known
place for pilgrimage. Paracelsus concludes his directions for its
manufacture with the words: _But if this be incomprehensible to you,
remember that only he who desires with his whole heart will find, and to
him only who knocks vehemently shall the door be opened_.'

'I shall never try to make it,' smiled Arthur.

'Then there was the _Electrum Magicum_, of which the wise made mirrors
wherein they were able to see not only the events of the past and of the
present, but the doings of men in daytime and at night. They might see
anything that had been written or spoken, and the person who said it,
and the causes that made him say it. But I like best the _Primum Ens
Melissae_. An elaborate prescription is given for its manufacture. It was
a remedy to prolong life, and not only Paracelsus, but his predecessors
Galen, Arnold of Villanova, and Raymond Lulli, had laboured studiously to
discover it.'

'Will it make me eighteen again?' cried Susie.

'It is guaranteed to do so,' answered Dr Porhoet gravely. 'Lesebren, a
physician to Louis XIV, gives an account of certain experiments witnessed
by himself. It appears that one of his friends prepared the remedy, and
his curiosity would not let him rest until he had seen with his own eyes
the effect of it.'

'That is the true scientific attitude,' laughed Arthur.

'He took every morning at sunrise a glass of white wine tinctured with
this preparation; and after using it for fourteen days his nails began to
fall out, without, however, causing him any pain. His courage failed him
at this point, and he gave the same dose to an old female servant. She
regained at least one of the characteristics of youth, much to her
astonishment, for she did not know that she had been taking a medicine,
and, becoming frightened, refused to continue. The experimenter then took
some grain, soaked it in the tincture, and gave it to an aged hen. On the
sixth day the bird began to lose its feathers, and kept on losing them
till it was naked as a newborn babe; but before two weeks had passed
other feathers grew, and these were more beautifully coloured than any
that fortunate hen had possessed in her youth. Her comb stood up, and she
began again to lay eggs.'

Arthur laughed heartily.

'I confess I like