habitants, has a death rate from typhoid approaching the average of Chicago and Toronto, though it is opposite Detroit, but the difference is due to the fact that Walkerville sewage passes into the river a few hundred yards above the Windsor intake pipe.

What is here stated will, I believe, prove to be a law of pollution, viz: That taking a series of years the pollution of even relatively immense bodies of lake water which, having no regular flow, are liable to carry sewage to a water intake will, at certain seasons and with winds moving sewage toward the point of supply, cause outbreaks of typhoid

*

more or less epidemic. I further believe that we can establish from these diagrams another law, viz: "That in cities obtaining practically all their drinking water from a public supply whose source is beyond the possibility of contamination, typhoid fever will practically disappear from the list of causes of mortality."

As regards diphtheria, from what I have said it will be gathered that I take it to be a fact that its prevalence depends directly in towns where public water is in general use upon direct contagion-in other words,

Thus a weekly analysis of Chicago water showed that with a southwest wind, continuing for a week, the albuminoid ammonia of the water rose from .065, gradually but constantly to. 120 per million parts. This wind moves sewage from the sewer outfalls toward the water intake pipe.

in those towns where municipal regulations are defective either in scope or in their enforcement, or in both. It thus becomes apparent that sanitation in the matter of these two diseases possesses two largely distinctive elements, one of which belongs peculiarly to the Department of Works, the other to the Department of the Officer of Health.

I have made this digression in order to explain what the first diagram apparently teaches, and now I shall return to the economic aspect which this diagram presents. You will see it in a moment in the second and third diagrams.

It will be seen that I have assumed that for each death from typhoid there are nineteen who do not die, at any rate, from this disease, although, as is too often the case, it supplies conditions by which the seeds of consumption obtain an entrance to the system and produce, sooner or later, their fatal effects as a sequel.

I have also assumed that each case of typhoid means the loss of a month to the patient and one month to the nurse, but have said nothing about the actual expenses of the sickness in physician's bills, medicines and undertaker's fees, all of which would be proper items in the logs of productive capital.

Taking, then, the figures as we find them, and with these approxi mately correct assumptions, we obtain the following for Chicago:

Cases .8 per 1,000 by 60 days for nurse and patient equals 960

days per 1,000.

And 960 days by 1,200 equals 1,152,000 days.

This divided by 300 working days equals 3,840 years, or the loss of the year's work of 3,840 men.

At one dollar a day this means the loss of $1,052,000 to Chicago for one year of sickness from typhoid alone. This rate would mean for Detroit a loss of $210,400, whereas Detroit actually did lose only $24,000. On the other hand, if the Detroit rate were attained by Chicago $800,000 would be saved, a sum which would pay the interest, at 3 per cent., on over $26,000,000 of capital to invest in new water works. Without discussing the losses from typhoid further, I turn to the deaths from that other disease par excellence of this northern temperate region, xiz: diphtheria.

I have had a chart arranged to show its prevalence as well. It must undoubtedly be considered the pest of our climate. Its microbe may multiply outside of the body like that of typhoid, but has in addition an extreme capacity for spreading by infection. From the tables I therefore draw the following conclusions, viz:

1. In a city or town with an average attention to sanitation we have a more or less constant presence of so-called sporadic cases, amounting, perhaps, in deaths to 3 or 6 per 1,000.

2. Under, however, peculiar seasonal atmospheric conditions (such as a prolonged, dry, warm autumn) the germs of the disease seem to freely

devolop in organic filth, hence an extension of the sporadic cases takes place; but mark the difference with typhoid.

3. Each case of these becomes a new center, each house wherein a case occurs being liable to become a distributing point. Persons, and especially children going to school, spread it broadcast unless the strictest municipal supervision is exercised over these cases and the public school.

4. That since the direct infection is enormously more common than in the sporadic cases, we have in this fact the evidence that the deaths from the disease are in a large degree preventable, and hence form a most important factor in this question of the economics of sanitation. Since 1880 this disease has undoubtedly had in the country, as a whole, a greater general prevalence than before, though its mortality in several years past has undoubtedly been lessening as compared with the cases occurring. This is but natural if we remember that its spores are vegetable and hence spread just as the spores of the black knot fungus have spread among the fruit trees. With regard to the latter we are aware that what is necessary to limit it is to remove at once a limb affected and burn the knot. We do not, however, imagine that the spores are all destroyed but only those which we have de tected on the knot.

It is quite clear, then, that with diphtheria the imperative question in its limitation is isolation or removal of the infeetion in cases. This may, in large degree, be done by municipal regulations, intelligently and perseveringly administered. That this is done much more. thoroughly in one city than another we are very well aware. Taking Detroit as an example: Here it appears that a single city had almost as many deaths in 1890 as had the whole Province of Ontario. Look across the river. We must remember that Windsor is the nearest suburb to the business portion of Detroit, and that there is a constant intercourse between the two cities. In spite of infection, therefore, being frequently brought to Windsor, the disease has been limited there by the active interference of one of the best officers in Canada, supported by most thorough regulations.

Compare Detroit with Hamilton, where the latter city has been under a most vigilant officer for ten years. There diphtheria has so steadily declined as to cause but a small percentage of deaths.

Observe what the losses mean. It may be taken as a fair average that one death occurs in every five cases of diphtheria. At least one nurse's services are constantly required for, say, an average of a fortnight. From these data it thus becomes easy to calculate, as in the case of typhoid, what the loss means. The rate of death is:

Typhoid, 5; 8 Diphtheria.

But we have assumed in the case of the first, twenty cases to one death, and with the latter five cases to one death. Hence the ratio of cases is. Typhoid, 20; 8 Diphtheria.

And if we assume that the loss in the latter is only one-third of the former in time, we can add what is probably below the real figure, about one-twelfth of the loss from diphtheria to the total average loss from typhoid for all the cities in the list.

Further comment seems needless. It surely is not necessary to add to all this the economic loss from doctors' bills, drug expenses and undertakers' charges, in order to show the extent to which these cities lose annually from imperfect sanitary methods.

We now must advert briefly to some of the methods which modern sanitary science has developed, and is still more rapidly improving, for overcoming the evils of defective sanitation.

Some of the important methods have already or will be set forth in the splended list of papers set down for discussion at the convention. I, therefore, need do but little more than refer to them. I shall do so in the following order:

First of all to be considered is the house we live in. Here we have to examine what is under the house, what is about the house, and what is within the house. As regards what is under the house, there are two principal things to be inquired into. With the presence of organic filth, which is made-up soil, from old refuse heaps, or filth from vegetables, etc., in the cellars, with moist walls, a house can hardly be made healthy. Cellars certainly can and must be kept clean and sweet. Lime-wash is a great cleanser, while concrete floors, etc., may help the first defect.

Boards decaying from damp in floors are most dangerous, and hence cellars must be drained. But this does not mean that we must let the water come in and then drain it off. Such cellars are always damp, the ground outside must be deeply drained, and to this end field tiles should be laid around the house and connected with field tiles laid in the same trenches with the sewers.

As regards what is around the house, we have especially to remove all organic filth from house slops and yard refuse, to remove heaps and all garbage of lanes and alleys. Hence a systematic sanitary inspection of yards and lanes is a necessity, associated with a frequent and thorough scavenging department. Gradually all yards and lanes should be paved with cobble-stones, or bricks, or other rock material.

As regards what is within the house, cleanliness, or freedom from organic filth must be our watchword. Closets and dark spaces must be tabooed. The fewer carpets and woolen hangings the better, and weekly cleanings are infinitely better than the old half-yearly attacks made upon the stored-up filth. These remarks must apply with the same and even greater force to the school-room, where, daily, forty or fifty children sit for hours, and are constantly inhaling the dust tracked in on boots and shaken from clothing; this, in the house and school, often is the dust of disease. The germs found in the air of rooms are found to be a thousand times more numerous than those in the outer air, even of a town, unless on a windy day.

In the sunshine, with oxygen, they are gradually destroyed, but being borne into the house they collect there, and if stirred up only settle again on the persons and into the lungs of the house-dweller. Among these, from time to time, are borne the germs of infectious disease, either from the outer air, but much more frequently with the boots, clothing and breath of persons from other infected houses or schools, or who have been suffering from disease itself. Thus we know from experience that in the winter months, when houses are closely shut up, these diseases become most prevalent. It thus becomes apparent that municipal control of houses, where infectious disease exists, should be of the most positive character. If the infection is in such a house, it must, for the sake of present and future inmates, be removed at whatever cost. But as we know this is most difficult, it is reasonable that we should allow as few infected houses as possible. Hence it is very much better to have all cases of these diseases removed to isolation houses, hospitals, etc., where they are usually better treated and where infection can be readily destroyed.

But another most dangerous inmate of the house is sewer air. I venture to say that our experience in Toronto is not peculiar to that city alone; and there it is found that not one system of plumbing in twenty will stand the forcing of smoke under pressure into the pipes where defective joints and pipes abound.

Thus drain and plumbing inspection, after the most approved modern fashion, is necessary in all houses already built, and is very easy of accomplishment in every house being constructed.

The fewer plumbing fixtures introduced into a house, the safer does such house remain. But this house plumbing has its exit into public drains and sewers. These in old towns are commonly most defective.