Complex sentence: The stammer has always been a significant part of the image of Dodgson: it is said that he stammered only in adult company and was free and fluent with children, but there is no evidence to support this idea.
Split into simpler sentences: The stammer has always been a significant part of the image of Dodgson. It is said that he stammered only in adult company and was free and fluent with children, but there is no evidence to support this idea.