Thank you so much for your incredible help when we spoke on thetelephone earlier. Since we first spoke I have subscribed to the OxfordEnglish Dictionary, which is a marvellous support.As I mentioned to you, I think I have found an earlier reference to the pathological definition of senile dementia to the one in the OED.
The OED states "1851 R DunglisonDict Med Sci (ed 8) Senile Dementia, Insanity of the Aged,"
The reference I have found is James Cowles Prichard Treatise on Insanity(London: Sherwood, Gilbert and Piper 1835)
"Senile dementia or the decay of the mental faculties is not the lot ofold persons universally, though it is a condition to which old age maybe said to have tendency, and to which in the last stage of bodily decaysome approximations are generally to be perceived". p92
If you could acknowledge receipt I would be most grateful.