soil-pipe atmosphere has already been noticed. The principles, then, which ought to govern the regulation of house drainage are mainly as follows:--

1. All filth and all organic waste matter which are liable to putrefy should be immediately and completely removed from the inside of the house.

2. All pipes (water-closet, bath, sink, or other) discharging such matters should, as far as at all possible, pass directly from the house apparatus to the outside of the house. Drains should not, if it

can be avoided, pass under a house.

3. A water-trap to close the house end of every such pipe should be so arranged as to be thoroughly open to view to its deepest part, that it may insist on being kept clean.

4. There should intervene between the trap and the house no cavity or surface, in or on which foul air or filth can accumulate. 5. All discharge pipes, inside or out of the house, should be well ventilated by openings at top and bottom. In the case of pipes passing through the house for any great distance this is imperatively called for.

If these principles are carried out efficiently, they will render it possible to maintain perfect cleanness in the house as regards the discharge of organic waste substances, and perfect immunity, I venture to assert, from any injurious effect on health from this indirect connection with the sewers.

DISCUSSION.

The CHAIRMAN said-I must say that I feel personally, as I am sure we all feel, very deeply indebted to Dr. Carmichael for the very admirable paper he has read, and, really, that paper conveys but a very faint and very inadequate idea of the amount of labour that he has bestowed on the subject. I was greatly struck and interested with the experiments Dr. Carmichael made formerly, and which he read to the Society; and with that in view, I spoke to him on this subject, and he has taken it up. But you can have no conception of the minuteness of detail and the delicacy of handling that such a subject requires. I had an opportunity of going over and seeing what Dr. Carmichael had done, and found to my very great surprise-in fact, I have not yet been able to solve the mystery-of how a man so busy as he is can have

devoted so much time to this subject. I know no one whose experiments are more trustworthy, or who bestows more care and attention on the conduct of these experiments; and I know, and am quite certain, that the half of the subject has not been told yet. I beg to propose that we accord him a cordial vote of thanks. (Applause.)

Dr. JAMES MORTON said he felt considerable diffidence in the presence of so many men learned on the subject, in rising to say a few words, but he trusted he was only breaking the ice, and that several of those gentlemen would speak afterwards. He sympathised so strongly with the remarks made by the Chairman, that he could not resist the temptation to say how much gratified he was with the paper of Dr. Carmichael. The feature in it which gratified him most, and which must have commended itself to the members of the Philosophical Society, was the extreme reluctance of Dr. Carmichael to draw any general conclusions. An amount of caution, which might be called scientific caution, was manifested by Dr. Carmichael, which was entirely creditable to him in every respect, and was particularly commendable in a young man. Some men were apt to be sanguine; Dr. Carmichael was serious, and had treated the subject in an exceedingly able manner.

Dr. WILLIAM WALLACE, City Analyst-We are very much obliged to Dr. Carmichael, because he has not brought before us any theory or haphazard statements, but statements of actual facts. These facts are of very great value. Some of us have had opinions which these experiments made by Dr. Carmichael bear upon, favourable to his views and the results of his experiments, and some otherwise. But it is of very little value indeed to hazard opinions when it is possible to make experiments, and Dr. Carmichael has taken the true way to arrive at the proper conclusion. All the experiments he has made are very accurate, and he has carried them out with great minuteness, and I have no doubt they have occupied him for a very great length of time. I have to add my testimony to the great value of Dr. Carmichael's paper.

Mr. BUCHAN-I beg to express, on my own behalf, the great debt we are under to Dr. Carmichael for the immense labour he has bestowed on his researches into this very important subject regarding the health of the community. It is a subject on which various men have been divided in opinion for many years. I have taken part in the battle, and, I am happy to say, the side that I

fought upon was the side which Dr. Carmichael has so well shown to be the right side. He has supported the value of one appliance which plumbers must use to protect the inmates of a house from the effects of the gases and disease-breeders which are in the drains and sewers. A great many medical gentlemen and engineers, and plumbers too, I find have been stating that the trap was a nuisance, that it should be done away with, and that there should be simply water in the pan, and so houses would be far safer without the trap than with it. I have taken the liberty on many occasions to say that that idea was absurd. Where you have a ball valve in place of a simple water-trap, it may very often happen that a bit of paper will stick to the ball or end of the pipe, and you have thus air blowing over a large surface from the drain or sewer into the house. In many cases where the medical adviser of a family has found disease, it has been found to come from defects in the apparatus. And, so far as I can remember, I have never found any medical practitioner, not even Dr. Fergus himself, say in my presence that disease had ever occurred in a family, or anywhere, from gases after they had passed through the water-trap. So far as I remember any case where disease was caused, it arose from defective joints, holes in the pipes, or sewer gases from the drain-gas getting into the house in some way, but not from water in the trap carrying disease-breeders into the house. If air with any germs in it was flowing into the apartments, these germs would attach themselves to the apparel in the apartments, or the paper in the rooms, or the furniture, or anything else, and would gradually accumulate; and that is one of the reasons why, even if the hole may not be very large in the soil-pipe, it will affect the room in the course of time, and be a source of deterioration to health even where there are no

actual disease-breeders in the case. I think the Society is very much indebted to Dr. Carmichael for the experiments which we have heard explained to-night.

Mr. W. R. W. SMITH-I have been very greatly gratified by the experiments which Dr. Carmichael has brought before us, but there is one little matter in reference to these soil gases that has always struck me, which those gentlemen making experiments have never taken into consideration, and I would desire to direct Dr. Carmichael's attention to it. He showed us certain vessels containing urine which had been exposed to sewer air. I wish to ask if he considered the conditions of the barometer at the time he was noticing the passage of that air? I have not any definite

experiments on the subject, but I have made a series of observations, and those have invariably led me to this idea that it depends upon the condition of the atmosphere whether there is a heavy current of sewer gas, or perhaps a current down the sewer pipe, although in some instances there is air produced, to a large extent, by passing through the pipe. That is a point which I think Dr. Carmichael, with the minutia which he has shown in his experiments, might do well to take into consideration.

Mr. BROMHEAD-After such a very carefully prepared and excellent scientific paper, it seems to me a pity that we should be taken aside from the real point. It seems to me that some of the speakers have very much misunderstood the lecturer, if it is supposed that he demonstrated that the apparatus which plumbers are now putting up are satisfactory. It seems to me that the whole moral of this very excellent address is that the water that has been used, perhaps in the machines that plumbers have been putting up, has been satisfactory to a certain extent; but I certainly understood the whole gist of the paper to mean that the apparatus that plumbers have put up to hold that water, to make them useful, have all to be cleansed to carry out the object for which they are intended. I would also ask that, in the printing of this paper, the illustrations which Dr. Carmichael has shown may be put into the book.

way

Dr. CARMICHAEL, in replying, said-I thank you very much for the in which you have received this paper. I can assure you it is only a very small portion of the work which I have brought before you. You have been kind enough to overlook certain imperfections in getting up the paper, which were inseparable from the attempt to condense what I had to say. Mr. Buchan was perfectly right in saying that the little valve at the top of the new closet outflow pipe was meant to ventilate that portion of the pipe. As to the remarks of Mr. Smith about the barometric pressure, I have only to say that I continued these experiments of mine regularly for from five to six months under all the varying conditions of atmospheric pressure. I think that eliminated the difficulty very thoroughly, and I have not yet entered into any particular effect of barometric pressure by way of experiment, because the fact is that experiments performed, as I have shown you, under whatever barometric pressure, gave invariably the same results. Mr. Bromhead has spoken of the structure of the traps. What I wish to demonstrate is that even such traps as those old

ones exclude the foul gas. arranged between the trap and the house, invariably admit of a portion of foul or dirty pipe, and that I want to have removed by having all the traps in sight.

The details, as they are at present

The vote of thanks having been passed to Dr. Carmichael,, the proceedings terminated.

XI-On Provident Dispensaries as a Means for promoting the Public Health. By JAMES CHRISTIE, A.M., M.D., Lecturer on Hygiene and Public Health, Anderson's College, Glasgow.

[Read before the Society, March 3rd, 1880.]

THE establishment of Provident Dispensaries in the metropolis and provinces has, during recent years, excited much attention among social reformers; and the efforts put forth in this direction have been, if not eminently successful, hopeful, to say the least of them.

Public attention was first called to this subject about twelve years ago, chiefly in consequence of the gross abuse of the metropolitan medical charities; and the first combined effort to remedy the existing evils was made exactly ten years ago, in March, 1870. At a meeting, presided over by the late Sir William Fergusson, at which 156 members of the medical profession were present, the following resolutions were passed:

"That this meeting is of opinion that there exists a great and increasing abuse of outdoor relief at the various hospitals and dispensaries of the metropolis which urgently requires a remedy;" and

"That, in the opinion of this meeting, the evils inseparable from the system of gratuitous medical relief administered at the outdoor department of hospitals, and in free dispensaries, can be in great measure met by the establishment, on a large scale, of Provident Dispensaries, not only in the metropolis, but throughout the kingdom, and by improved administration of Poor Law medical relief."

A large committee was then appointed, which apportioned the subject among four strong sub-committees on " General Hospitals," "Special Hospitals," "Dispensaries," and "Poor Law Medical Relief," of which Dr. Meadows, Dr. J. E. Pollock, Dr. Stewart,