Actually, I found this reference which stated that 1895 was one of the first times Russell spoke against tobacco use.
*** w95 5/15 p. 23 par. 11 Part 2—Flashes of Light—Great and Small ***
As a result of increased light, habits at first merely frowned upon were later handled with appropriate gravity. An example of this was in connection with the use of tobacco. In Zion’s Watch Tower of August 1, 1895, Brother Russell directed attention to 1 Corinthians 10:31 and 2 Corinthians 7:1 and wrote: “I cannot see how it would be to God’s glory, or to his own profit, for any Christian to use tobacco in any form.” Since 1973 it has been clearly understood that no tobacco user can be one of Jehovah’s Witnesses.