general reader, he need only be told that tetanus is nearly always caused by mechanical injuries, and that the natural increase of these in a place like Chicago may account for a large part of the increase. Yet, taking the record as a whole, and viewing it only with a calm desire to get at the truth, it is not possible to avoid seeing that the growth of nerve maladies has been inordinate. The industry and energy which have built this great city on a morass, and made it a vast centre of insatiate commerce, are now at work to undermine the nervous systems of its restless and eager people,[1] with what result I have here tried to point out, chiefly because it is an illustration in the most concentrated form of causes which are at work elsewhere throughout the land. [Footnote 1: I asked two citizens of this uneasy town--on the same day--what was their business. Both replied tranquilly that they were speculators!] The facts I have given establish the disproportionate increase in one great city of those diseases which are largely produced by the strain on the nervous system resulting from the toils and competitions of a community growing rapidly and stimulated to its utmost capacity. Probably the same rule would be found to apply to other large towns, but I have not had time to study the statistics of any of them fully; and, for reasons already given, Chicago may be taken as a typical illustration. It were interesting to-day to question the later statistics of this great business-centre; to see if the answers would weaken or reinforce the conclusions drawn in 1871. I have seen it anew of late with its population of 700,000 souls. It is a place to-day to excite wonder, and pity, and fear. All the tides of its life move with bustling swiftness. Nowhere else are the streets more full, and nowhere else are the faces so expressive of preoccupation, of anxiety, of excitement. It is making money fast and accumulating a physiological debt of which that bitter creditor, the future, will one day demand payment. If I have made myself understood, we are now prepared to apply some of our knowledge to the solution of certain awkward questions which force themselves daily upon the attention of every thoughtful and observant physician, and have thus opened a way to the discussion of the causes which, as I believe, are deeply affecting the mental and physical health of working Americans. Some of these are due to the climatic conditions under which all work must be done in this country, some are out-growths of our modes of labor, and some go back to social habitudes and defective methods of early educational training.