A published letter to Mr.Richard Taylor, dated March 11, 1843, contains an allusion to his previous condition.

'You are aware,' he says, 'that considerations regarding health have prevented me from working or reading on science for the last two years.' This, at one period or another of their lives, seems to be the fate of most great investigators.

They do not know the limits of their constitutional strength until they have transgressed them.

It is, perhaps, right that they should transgress them, in order to ascertain where they lie.
Faraday, however, though he went far towards it, did not push his transgression beyond his power of restitution.

In 1841 Mrs.Faraday and he went to Switzerland, under the affectionate charge of her brother, Mr.George Barnard, the artist.