had indeed suffered from enteric fever, and, laborers having laid bare the drains, these were all seen to communicate with the sewer above mentioned, this being further of such faulty construction as to be little better than an elongated cesspool.

In view of the danger of direct communication between a sewer and our dwellings, "What," you may fairly ask, "is the remedy?" I answer that the remedy is simply breaking the direct connection which has been referred to. In the case of a waste-pipe from a sink, the pipe should be brought through the wall into the outer air, and there be cut off, its contents flowing to a trapped drain-inlet outside the dwelling. (This point was explained by means of diagrams.) This principle of disconnection is, however, of much wider application than I have as yet indicated. All waste-pipes coming from lavatories, baths, water-closets, etc., as also the overflow-pipes from cisterns, and the rain-pipes, especially such as have their heads anywhere near windows, or beneath overhanging eaves, should, like the sink-pipes, have an airspace intervening between them and the drain-inlets into which they empty.

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There is exceptional danger in the direct connection which is often maintained between houses and the sewers by means of the overflowpipes of cisterns. These pipes are very generally provided with a siphon-bend," but the water constituting the trapping is often absent. The ball-cock of the cistern is intentionally so contrived as to prevent overflow, and hence, when once evaporation of the water in the trap has taken place, sewer-air passes through it without let or hindrance..

Adapting the principle of disconnection to the house-drain itself, I would further urge that an air-break should always be contrived between the end of the drain and a trapped inlet leading to the public sewer; the more so as when this is effected a further safeguard can be insured, namely, two ventilating apertures to the drain, and the maintenance of a constant current of air through its entire length.

(The conveying of infection by means of an "intermittent watersupply" was next described.)

I feel sure that many other methods by which water can act as a vehicle for conveying infection will occur to you. Milk, also, must be regarded as at least an equally important medium for the transmission of infection. I shall, however, ask your further consideration only of certain distributions of ice and cream as forming channels by which disease may be conveyed to households.

I believe that the first instance in which the consumption of ice was shown to have been followed by an outbreak of disease is that recorded in the "Seventh Annual Report of the State Board of Health of Massachusetts." The occurrence took place in one of the large hotels at Rye Beach, New Hampshire. At the beginning of the season

of 1875 about a thousand visitors were assembled at Rye Beach, and a considerable number were attacked with a series of symptoms which led to the suspicion that they had consumed some noxious article. The incidence of the disease was entirely confined to three hundred persons occupying one of the large hotels. The sanitary state of this hotel is said to have been exceptionally good, and, although suspicion seemed at first to attach to the water-supply, yet the disease was found to have affected many who, "having apprehended trouble from the use of the water," which was strongly impregnated with salts of lime and magnesia, “had carefully limited themselves since their arrival to other beverages." Indeed, as the result of a careful process of elimination, suspicion came at last to be directed to the ice furnished to the house. The water obtained by melting the ice was discolored and charged with suspended matter, and gave off a decidedly disagreeable odor; the atmosphere of the ice-house was offensive, and some persons who had used the ice away from the hotel were found to have suffered in the same way from violent illness. The ice in question had been derived from a local pond, the water of which was found to have become foul from long-continued stagnation; one portion of the pond, measur ing about five hundred feet in length and one hundred and fifty feet in width, was occupied by "a homogeneous mass of putrescent matter." A piece of ice, carefully cleansed from all surface impurities, was then melted, and the water thus obtained was submitted to chemical analysis, the result being the detection in it of a quantity of "decaying organic matter." The use of the ice had also in the mean time been discontinued, and coincident with its disuse "there was observed an abrupt amelioration in the symptoms of nearly all who had hitherto been ill." So, also, no fresh attacks occurred during the remainder of the season.

Even among the more educated classes there prevails an impression that even if water is contaminated it is purified by freezing. Many experiments have, however, shown the fallacy of this view. In some of these made recently by Mr. C. P. Pengra, an American chemist, various organic matters (urea, albumen, etc.) were mixed with water, and the specimens were gradually frozen. A certain amount of purification did take place-the ice containing thirty and even forty per cent less organic matter than the unfrozen liquid. But a large amount of the added pollution remained, and the investigator, though expressing surprise that the purification had been as great as it was, says that the experiments afford abundant proof that we ought not to tolerate the indiscriminate collection of ice.

These experiments do not, however, prove that the contagium of an infectious fever can withstand the process of freezing, but as to this we are not left in doubt. Dr. E. Klein, F. R. S., thus reports the results of some of his experiments in freezing bacillus anthracis: "I have exposed in a capillary pipette fluid full of spores to the influence

of ether spray, and, having thus kept the liquid frozen for several minutes, have injected it into the Guinea-pig and rabbit with fatal result. . . I then placed a capillary tube filled with spores in a mixture of ice and salt, and kept it there for one hour exposed to a temperature of 12° to 15° Cent. below freezing-point; after thawing, the material was injected into the subcutaneous tissue of a Guinea-pig. This animal died of typical anthrax on the third day.”

We are thus bound to accept the position that the morbific organisms, the introduction of which into the human system produces specific infectious diseases, are not destroyed by freezing, but, on the contrary, that ice collected from an infected water and supplied to households would act as a vehicle for the introduction of the poison of those diseases. In short, a wholesome ice can be derived only from a wholesome water.

I now pass to my last point. On the 9th of June, 1875, a party of sixteen persons sat down to dinner at a house in South Kensington, and later on in the evening about one hundred and fifty additional guests assembled with the family of the host and hostess in the drawing-room; the service of the house was also re-enforced for the evening by seven extra servants. Within five days eighteen of the assembled guests suffered from more or less well-marked attacks of scarlet fever; two others had “ sore throats"; one of the waiters had scarlet fever; and a few days later a lady, not at the house on the 9th, but who lunched there the next day, was found to be suffering from a distinct attack of the disease. In all, twenty-two persons were attacked.

The circumstances of the outbreak were investigated by Dr. Buchanan, F. R. S., and his report on it is specially instructive as indicating the method in which such an inquiry should be conducted. It was ascertained that the scarlet fever could not have been communicated by any of the guests, by any member of the host's family, nor by any of the servants, nor indeed did the circumstances of the outbreak suggest infection from such a source. On the other hand, strong circumstantial evidence was forthcoming in favor of the infection having been communicated by means of some article of food or drink.

The dinner guests were the principal ones affected; several of the household who could not have touched any of the articles of food served up escaped altogether, and there was a marked incidence of the disease on those who had several opportunities of eating certain exceptional articles supplied on that day. Up to this point, however, no one article of food had come under suspicion.

Two special supplies of cream were delivered at the house on the day of the entertainment; one, which arrived at 4 P. M., was "double cream" from a London dairy, and was used for ice-puddings, custards, and "creams"; the other, arriving at 5 P. M., was from a Hampshire dairy, and was mainly used as cream. The latter supply was generally

used by all the evening guests, among whom there was but little scarlet fever; the former, or four-o'clock, cream was distributed essentially to the family and to the dinner guests. It was again used at luncheon the next day, and thirteen persons who were known to have had opportunity of partaking of it suffered from scarlet fever within five days. The bulk of this four-o'clock cream was used in the preparation of articles which had to be boiled previous to their being used in a cool or frozen form, and those persons who partook of such articles alone were not specially attacked. But of this cream some that was in excess of the cook's requirements was put into at least one jug along with the five-o'clock cream.

This mingling of the two creams added materially to the difficulty of the investigation, because it was that remnant of the four-o'clock cream which had not been boiled previous to use to which interest was now found specially to attach. For "no less than seven ladies who were at the dinner, and who took cream in their coffee in the drawingroom, afterward became ill, none of them who took that cream having escaped." There was, however, no such incidence of disease on the gentlemen who took coffee down-stairs. And further, whereas all who partook of cream on the day following the dinner were ill, none of those who did not partake of it suffered. Now, it was known that it was the four-o'clock cream that was used at the luncheon on the 10th, and if it so happened that the cream which was sent up into the drawing-room with coffee for the ladies who had left the dinner-table was the jug of mingled cream, then that four-o'clock supply from the London dairy comes strongly under suspicion.

The complicated nature of the conditions which had to be contended with in pursuing such an investigation in the metropolis forbade any conclusive demonstration as to the exact method by which this special cream-supply may have become infected. It was, however, ascertained that upon one section of the London dairyman's customers there had been a large incidence of scarlet fever, and a suspicious history as to scarlet fever in the person of one of the dairy-staff who was engaged in milking and carrying. out the milk was also elicited. In short, there is little doubt that the cream supplied from this dairy was the vehicle by which the infection of scarlet fever was conveyed to that household in South Kensington.

Some years ago I conducted a somewhat similar inquiry. The same disease had attacked a large proportion of persons who had met at a London dinner-table, and the source of infection must have been some article of food. In this case, fruit as well as cream came under suspicion, and the employment as strawberry-gatherers of persons in the desquamative stage of scarlet fever seemed as likely a source of infection as that which might have operated through the agency of a dairy. The circumstances were, however, too complex to be unraveled, and further inquiry was abandoned.

VOL. XXIV.-6

In considering each of the previous channels of infection I have pointed to some remedy. That which promises most in dealing with infection conveyed in the manner just indicated is the early isolation of persons suffering from the several infectious fevers.

แ

REMARKS ON THE INFLUENCE OF SCIENCE.*
BY LESLIE STEPHEN.

"IF it were a qualification for his office," Mr. Stephen remarked, “to

be impartial in the sense of not having an opinion on the matter, it would have been hardly possible to select a less qualified chairman in all London than himself. He believed that the spread of scientific influence had not only not been bad, but that the thing of which we stand most in need is a great deal more scientific thought and method in every direction. He felt, however, that his case was so strong that he could afford to give points to the opposite side; and for this reason, and because to a certain extent he was prepared to go with the opener in his remarks, he hoped to be able to point out fairly where the various arguments which had been used found their proper place. The only definition, or rather description, of science which ever appeared satisfactory to him was, that Science is that body of truths which may be held to be definitely established, so that no reasonable person doubts them. To speak of mischievous science is, therefore, to assert that truth is mischievous, an assertion to which no one would be likely to seriously agree, especially in such a place as University College. If it is to be supposed that science is mischievous, it must either be meant that certain false theories which call themselves science are wrongful, which may well be the case, or that the scientific progress at the present time happens to be exercising a mischievous influence.

"No one denies that science may accidentally lead to a large number of our particular mischiefs, as in the case of the invention of dynamite; but it can not in any way be admitted on that account that science is mischievous. For the question arises, If science is bad, what can be substituted for it? and in what way will these mischiefs be remedied if we are not scientific? It is impossible to say that erroneous impressions will make us better off than correct ones. For instance, the old belief in medicine subjected people to years of tor

* Remarks by Mr. Leslie Stephen in summing up a debate at University College, London, on the motion by Mr. B. Paul Newman: "That the spread of scientific thought and method has, on the whole, exercised an injurious influence on English society." The motion was supported by Mr. N. Mickleman, and opposed by the Rev. A. Capes Tarbolton and Mr. J. G. Pease.