closing the proper stopcocks, to supply the heart from B and let it pump into A, and so on, to and fro, with the good blood for a certain time. At short intervals the blood pumped out by the heart in a minute was collected separately and measured. As soon as it was found that this work was pretty constant, varying not more than 10 cubic centimetres in a minute, the good blood was shut off and the poisoned blood from C turned on; this was pumped into D and collected there. While this poisoned blood was circulating, the quantity pumped out by the heart was measured from minute to minute; then good blood again turned on, and the measuring continued. Any experiment in which the heart did not under these circumstances show marked recovery from the action of the alcohol was rejected, so as to avoid the risk of ascribing to the alcohol something which was possibly due to independent death of the heart.

The general result of our experiments may be primarily stated as follows: Blood containing one-eighth per cent. by volume of absolute alcohol has no immediate action on the isolated heart. Blood containing one-fourth per cent. by volume, that is two and a half parts per thousand of absolute alcohol, almost invariably remarkably diminishes within a minute the work done by the heart; blood containing one-half per cent. always diminishes it, and may even bring the amount pumped out by the left ventricle to so small a quantity that it is not sufficient to supply the coronary arteries; hence blood is drained off by them from the outflow tube and at last none is pumped out from its upper end at all.

I have graphically indicated in the diagrams* on the wall the results of two experiments with one-fourth per cent. alcoholised blood. Each inch on ordinates drawn from the abscissa line to the curve represents ten cubic centimetres in a minute. You see that when the poisoned blood is administered the work done by the heart falls very markedly, but that shortly after the poisoned blood has been replaced by good, the curve of work rises to near its original height.

We may here point out that the dose of alcohol was not a priori a large one. A man weighing 150 lbs. contains about 11 lbs. of blood; one-quarter per cent. of this is 0.46 of an ounce, a quantity exceeded by that in a single ordinary drink of brandy, and some people take a good many such drinks in a day. Moreover, the alcoholised blood in our experiments could hardly have acted directly on the heart as it flowed through its cavities; it must almost certainly have acted only

*The diagrams referred to in the text were exhibited at the meeting, but have not been here reproduced.

after it flowed through the coronary arteries to the capillaries of the organ and came into close relation with its muscular and nervous tissues. To get to these capillaries it had first to circulate through the lungs, and there no doubt some of even the small quantity of alcohol present was eliminated.

What is the cause of this diminution in the quantity of blood pumped out? To enable us to decide this, the first thing to do was to exclude any difference in the rate of supply to the right auricle. It might be that the flask A, for example, fed the heart more freely than C. That this was not so was easily tested by changing the contents of the flasks, and putting good blood into C and alcoholised blood into A, and then trying again. This was done in several experiments, and always with the same result; no matter which flask or set of connecting tubes was used, the amount of blood pumped round by the heart was much less if it contained alcohol.

Differences in the flasks and rubber tubes being excluded as causes of the phenomenon, we have to seek for it in some action exerted by the drug on the living organs; and here several possibilities suggest themselves. It might be that the alcohol constricted the pulmonary vessels, and so prevented the blood from reaching the left ventricle as freely as before; or it might be that it dilated the coronary arteries and so drained off more blood through the coronary circuit, and thus left less to be pumped out from the exit of the outflow tube; or it might be that the pumping power or the capacity of the left ventricle was altered; or, of course, there might be combinations of these.

We were set on the right track one day when we modified the experiment by cutting away the pericardium before administering the alcohol. To our surprise, even blood containing per cent. of alcohol now had little or no effect on the work done by the heart. The curve obtained from such an experiment is shown in diagram 5. You see four doses of alcohol in all were administered, and no one of them had more than the most trivial influence upon the quantity of blood pumped out by the heart in a minute.

We tried this repeatedly in another manner. Keeping the heart in the pericardium, we administered alcohol and got the usual result; then recovered the heart by good blood, cut away the pericardium, again gave alcohol, and now with little effect. As the absence of the pericardium could hardly in any conceivable manner prevent constriction of the lung arterioles, or prevent dilatation of the coronary vessels, it was clear that neither of these would account for the results of the administration of alcohol.

Our attention was therefore turned to the proper heart substance. It has been proved by Roy, Gaskell, Donaldson and Stevens, Ringer,* and others, that various substances so modify the frog's heart as to make its diastolic relaxation incomplete, and hence diminish the quantity of blood pumped out from it at each systole; other substances produce exactly the reverse effect; they put the heart into a flabby condition, in which its diastolic bulk is greater than normal and its systole is never complete. It might be that alcohol acted in this manner upon the mammalian heart, and direct observation of the organ, in fact, showed it to become enormously distended when supplied with the alcoholised blood. Normally the dog's ventricle contracts so as to completely empty itself and obliterate its cavity. Under the influence of alcohol this is entirely changed; the ventricle ceases to contract completely; even at the height of its systole the organ completely or nearly completely fills the pericardiac sac; in its diastole it has little or no room to expand further and take in a fresh supply of blood. Hence a great diminution in the quantity of blood which it has ready to pump out at its next contraction. If now the pericardium be cut away, the heart enlarges enormously in diastole, takes in its usual quantity of blood, and drives it out at the systole; hence the organ performs its usual amount of work. This seems to show that the muscular power of the organ is not at first influenced; if the heart be not confined in the pericardium, and the quantity of alcohol in the blood flowing through it do not exceed per cent. by volume, the work done is not affected, at least for a considerable time. It is not the contractile power, but the elasticity of the cardiac muscle that is influenced; its "tone" is lowered, and it works under new and, when the pericardium is present, very unfavorable conditions. It acts like a greatly relaxed muscle, which contracts to half its normal extent, compared with a healthy muscle, in good tonic state, which when fully extended is shorter than the atonic, and whenever it contracts, contracts more completely; and, so far as the heart is concerned, to the fullest possible extent. If, however, the

*Since this paper was read (April 27, 1883), and an abstract of it published, an article by Ringer and Sainsbury has been published in the Practitioner. They investigated the action of several alcohols on the ventricle of the frog's heart, and find that all those examined stop the heart in diastole, when administered until they cause cessation of the beat. This makes it still more probable that the action of ethyl alcohol on the heart of the dog is directly exerted on the muscular tissue.

administration of alcoholised blood of or per cent. be long continued, or if blood containing 1 per cent. of alcohol be used, then, even with the pericardium removed, the systole becomes feebler and feebler, the work done less and less, and finally nil.

Whether alcohol directly combines with the cardiac muscular tissue, or whether it indirectly influences it by interfering with its nutrition, we are not able to say. The rapidity with which the effect manifests itself seems in favor of direct poisoning; on the other hand, the dog's heart will only bear a very brief deprivation of oxygen, and it has been shown that alcohol added to blood makes it hold its oxygen more firmly and yield it less readily to the tissues; and the heart subjected to alcohol has very much the appearance of the heart of an asphyxiated animal. On the whole we are inclined to think that the poisoning is direct.

We have made a few experiments to see what dose of alcohol given by the stomach to a dog will produce some similar action on the heart. When the heart lies in the body and in connection with the central nervous system there are of course considerable difficulties to be overcome, and all we can say as yet is that to get any distinct influence on blood pressure one must put much more alcohol into the stomach than an amount equal to one-fourth per cent. of the total blood in the animal. It is either not absorbed fast enough to reach at any moment the heart-poisoning limit, or, more probably, is picked up by other organs, very likely the liver, and held back from the heart.

We then tried in another way, by directly injecting into the jugular vein of a curarised dog a small quantity of salt solution containing an amount of alcohol equal to one-fourth per cent. of the total blood of the animal, reckoned as one-thirteenth of its weight. In such cases we found usually a very temporary enfeeblement of the heart, indicated by a lower arterial pressure, but this seems only to last while the injected solution is flowing through the organ or for a few seconds afterwards. Before the blood returns it has apparently deposited its alcohol elsewhere in the body, or at any rate got rid of it somehow, so that it no longer acts immediately upon the heart, at least to a directly noticeable extent. No doubt, even quantities of alcohol in the blood much less than our one-fourth per cent. if kept circulating through the heart, day after day, will influence the organ injuriously; the "whiskey heart" is too well known for us to doubt this. But a study of such chronic action is rather pathological than physiological, and lay beyond the scope of our enquiry.

VOLUNTEER PAPERS.

THE SEWERAGE OF CITIES. LIERNUR'S PNEUMATIC

SYSTEM.

BY C. W. CHANCELLOR, M. D.,

Secretary of the State Board of Health of Maryland. •

Of all questions which affect the prosperity and development of large cities, there is not one paramount to that of drainage and the removal of offal. Towns are in this respect like living beings. If the organs serving as outlets for waste products become choked or impaired, a vigorous existence, however abundant the means for supporting it may be, becomes impossible. The question, whether or not town drainage takes place in keeping with the laws of sanitation and economy, involves not only our health, comfort and cleanliness, but also the amount of our taxation, the purity of our rivers, and even our national wealth.

"Every living organism," says Liebig, "produces in its offal the manurial ingredients, both quantitative and qualitative, required for reproducing the means of sustaining its life. It is the law of the circuit of atoms, each playing a part in a long-stretched series of acts of nature, serving consecutively various purposes, and beginning the series anew each time the circuit is completed. Thus the dung of cattle contains all fertilizing properties needed for growing their food, whilst that of carnivorous animals supplies the manure for producing the food of the creatures on which they prey; and so it is with every living being, including man. Hence it is unquestionable that the nitrogen, phosphorus, phosphoric acid, potash and other organic and inorganic matters contained in the excretal sewage of cities will suffice for producing food for the people it is derived from." But, as a rule, this fact is ignored. And at what cost! In order to maintain the fertility of our soil, so far as it is impaired by cultivation, we import from Peru and Chili, in the form of guano, the