Scientific interest won for him the friendship of Boyle; and while he was administering physic to the patients of Dr.Thomas, he was making the observations recorded in Boyle's _History of the Air_ which Locke himself edited after the death of his friend.
Meanwhile accident had turned his life into far different paths.

An appointment as secretary to a special ambassador opened up to him a diplomatic career; but his sturdy commonsense showed him his unfitness for such labors.

After his visit to Prussia he returned to Oxford, and there, in 1667, in the course of his medical work, he met Anthony Ashley, the later Lord Shaftesbury and the Ahitophel of Dryden's great satire.

The two men were warmly attracted to each other, and Locke accepted an appointment as physician to Lord Ashley's household.

But he was also much more than this.