Full Idea
A series of elastic balls can successively communicate motion to one another. If mental substances communicated consciousness in this way, the last substance would be conscious of the previous states, but would not be the very same person.
Gist of Idea
As balls communicate motion, so substances could communicate consciousness, but not retain identity
Source
Immanuel Kant (Critique of Pure Reason [1781], B406-/A364)
Book Reference
Kant,Immanuel: 'Critique of Pure Reason', ed/tr. Guyer,P /Wood,A W [CUO 1998], p.423
A Reaction
A nice attack on John Locke's proposal, though Locke was aware of this scenario, and claimed the identity followed the consciousness. Clearly, though, if I share my thoughts with you, you don't instantly become me!