In reply to your letter, I should say that tobacco has some action on the brain; but I think its action different in different people, and at different times in the same person. I think the action soothing after food, but exciting on an empty stomach. In the former case I think it promotes thinking in this way:—that the mind concentrates its attention better during the mechanical operation of "puffing", than when it is liable to be disturbed when not so occupied. For this reason I should say that smoking does help to get through work late at night. I find frequently that having commenced to write with a fresh pipe in my mouth, I go on a long time after it goes out; but as it remains in my mouth, it seems to have almost the same effect till the discovery, at some pause, that my pipe is out; and then it is a relaxation to spare a moment to refill it. I do not look upon smoking as a necessity to mental labour; but it seems to me, as a smoker, an agreeable and useful method for concentrating thought upon any subject. But I think it would be difficult to lay down any general rule for persons of different constitutions.

E. POCKNELL.
March 10, 1882.