MY business this evening is to talk about dust: meaning by dust all suspended foreign matter of whatever kind, and including smoke and fog under the one heading. Coming from England I should naturally begin by saying, well, we all know what dust and smoke are; and even in Canada, I suppose, I may venture to say the same, though I am bound to say that your country, at present, shows a remarkable deficiency in this respect. In an English town dust and smoke are the most noticeable features, and are always ready to perform any insanitary or other function that may be expected of them. In this clear atmosphere none of these functions can be properly performed; disease-germs must languish and die, and their sworn foes, the white corpuscles of the human blood, must thrive amain. Let me say, however, that the air here is not so absolutely free from smoke as I had hoped to find it. Compared with an English town it is a splendid contrast; compared with one's ideal it falls short. Your houses may indeed burn anthracite and wood, but your passenger locomotives do not: I can attest from very recent personal experience, in a journey across this continent, that some of your locomotives emit almost as much smoke as a Clyde steamer, and that the journey would have been much pleasanter if they had emitted less. I also see some factory chimneys rising here and there. If you be not warned in time, you will not realise the blessing of fresh and pure air until you have lost it. It is good to have large manufactures, it is better to retain healthy and pure air. But with proper care the two may go together. Once lose ground in this respect, as we have done in England, and terribly uphill will be the retracement of your steps. The old country has in many things made experiments for you—experiments of which you may reap the benefit, without repeating them, if you choose. The experiment, of Protection, which we have tried and abandoned, I dare not here mention except just by name; but I dare mention the experiment we have tried only too successfully, and by no means yet abandoned though we groan under it—that of fouling the atmosphere, wherever a large number of human beings have to live in it, to such an extent that it is not fit to breathe. We have made a terrible mistake, and one that will take perhaps a century to undo. Tax all the necessaries of life and it is a small evil, for the tax may at any time by an Act of Parliament be removed, but pollute the air in which a people have to live and no one can see the end of the evil You will soon have towns here rivalling Liverpool and Glasgow and Manchester in size, and some day London. Be warned in time.