"It appears that arrangements have been made for opening this line on the 10th [of January] for public traffic, but as the 1st of October, the 1st of November, the middle of December have been announced from time to time as the probable date of opening, it is presumed that no one will feel disappointed if a further postponement should take place. " From this excellent page on the Tube's opening.
On the actual day of opening The Daily Telegraph reported:
"Of the general comfort in travelling on the line there can be no question, and the novel introduction of gas into the carriages is calculated to dispel any unpleasant feeling which passengers, especially ladies, might entertain against riding for so long a distance through a tunnel. "
Any gas that I experience being introduced while I'm in a tunnel is calculated to make me hold my nose and change carriages at the next stop.