Strand Theater, 10 P. M., gallery 0.101 parts CO_{2} per 100. Surrey Theater, 10 P. M., boxes 0.111 " " " Surrey Theater, 12 P. M., boxes 0.218 " " " Olympia Theater, 11.30 P. M., boxes 0.082 " " " Olympia Theater, 11.55 P. M.., boxes 0.101 " " " Victoria Theater, 10 P. M., boxes 0.126 " " " Haymarket Theater, 11.30 P. M., dress circle 0.076 " " " City of London Theater, 11.15 P. M., pit 0.252 " " " Standard Theater, 11 P. M., pit 0.320 " " " Theater Royal, Manchester, pit 0.2734 " " " Grand Theater, Leeds, pit 0.150 " " " Grand Theater, Leeds, upper circle 0.143 " " " Grand Theater, balcony 0.142 " " " Prince's Theater, Manchester 0.11-0.17 " " (Analyses made by Drs. Smith, Bernays, and De Chaumont.) Compare with these figures some analyses of the air of sewers. Dr. Russell, of Glasgow, found the air of a well-ventilated and flushed sewer to contain 0.051 vols. of CO_{2}. The late Prof. W. Ripley Nichols conducted many careful experiments on the amount of carbonic acid in the Boston sewers, and found the following averages, viz., 0.087, 0.082, 0.115, 0.107, 0.08, or much less than the above analyses of theater air showed. He states: "It appears from these examinations that the air even in a tide-locked sewer does not differ from the standard as much as many no doubt suppose." A comparison of the number of bacteria found in a cubic foot of air inside of a theater and in the street air would form a more convincing statement, but I have been unable to find published records of any such bacteriological tests. Nevertheless, we know that while the atmosphere contains some bacteria, the indoor air of crowded assembly halls, laden with floating dust, is particularly rich in living micro-organisms. This has been proved by Tyndall, Miquel, Frankland, and other scientists; and in this connection should be mentioned one point of much importance, ascertained quite recently, namely, that the air of sewers, contrary to expectation, is remarkably free from germs. An analysis of the air in the sewers under the Houses of Parliament, London, showed that the number of micro-organisms was much less than that in the atmosphere outside of the building.