My great grandfather was born in Madras in 1878, his brother 1877. His parents were Duncan Mearns Cruickshank ( Principal of the college in Madras, born in Aberdeen) and wife, JOANNA AMELIA DALTON. Sadly, Joanna died when John was born, before she reached the age of 20. Her parents were THOMAS DALTON and Amelia Lursell, who were married in Madras, and as far as I can find, both were born in Madras.
Apart from Joanna, there were 3 other children including Charles and Vitalis Dalton. Thomas is shown as a corporal in the 105th Regiment at the time of Charles' birth in 1861.
I can find Daltons in Madras for several generations, even though I cannot definitely tie them to my ancestors. I would be glad to hear from anyone who can point me at a source of information on Daltons in India, and where they came from.