country." Digby replied that he was forced to it. "If he went not now he
must starve." He plainly saw who was the real and only force in England;
and he was going to make a bargain with the strong man for himself and his
co-religionists. As a matter of fact there is no trace of his return at
this moment. Not merely was his property in danger, but his head as well.
Yet he never repented of his policy, and he carried it out, so far as might
be, in his dealings with Cromwell a few years later. And Henrietta Maria
bore him no grudge on this score.

Exile in Paris meant friendly intercourse with, and consolation of the
Queen, but also scientific research. In 1651 Evelyn was visiting him there,
and being stirred by his enthusiasm into attending Fébur's chemistry
lectures along with him. Before that must have taken place his pilgrimage
to Descartes, who died in 1650. Apparently Sir Kenelm had gone to Egmont as
an unknown stranger; and it throws light on his wide reputation as a man of
ideas and a conversationalist, that into his torrent of questions and
speculation Descartes broke with, "You can be none other than Digby." The
English scientist's practical mind--for he had always a practical end in
view, however fantastic his methods--showed itself in his counsel to the
author of the _Discours sur la Méthode_. Why all this labour for mere
abstract speculation? Why not apply his genius to the one great subject,
the prolongation of human life? Descartes, it appears, did not need the
advice. He said the subject was engaging his mind; and though he "dared not
look forward to man being rendered immortal, he was quite certain his
length of life could be made equal to the patriarch's." In fact, he was
composing at the time an _Abrégé de Médecine_, and popular report said he
believed men could live four or five hundred years. He died prematurely of
too much faith in his own medical theories.

In 1653 permission was given to Digby to return, on condition he would not