NOTICE.

The SOCIETY OF ARTS, established in conformity with the plan of the Massachusetts Institute of Technology, as set forth in the act of incorporation, April, 1861, held its first meeting on April 8, 1862.

The objects of the Society are to awaken and maintain an active interest in the practical sciences, and to aid generally in their advancement in connection with arts, agriculture, manufactures, and commerce. Regular meetings are held semi-monthly from October to May, inclusive, in the Institute building; and at each meeting communications are presented on some subjects germane to the objects of the Society, as stated above.

The present volume contains the abstracts of the communications made during the year ending Oct. 1, 1886, most of the business portions of the records being omitted.

The thanks of the Society are due to the publisher of the Army and Navy Journal for the loan of the electrotypes used in illustrating Lieut. Zalinski's paper on "The Pneumatic Dynamite Gun," and to the Creque Manufacturing Company for those illustrating Mr. Creque's paper.

The Proceedings of the six preceding years have been published in the same form as this volume, and the Proceedings of the first seventeen years of the Society are now in active preparation for the press. Copies of the publication may be obtained of the Secretary.

For the opinions advanced by any of the speakers, the Society assumes no responsibility.

LINUS FAUNCE,

BOSTON, June, 1886,

SECRETARY.

PROCEEDINGS OF THE SOCIETY OF ARTS

FOR THE TWENTY-FOURTH YEAR.

MEETING 336.

Relative Poisonous Properties of (Illuminating) Coal and Water Gas.

BY PROF. W. T. SEDGWICK.

The 336th meeting of the SOCIETY OF ARTS was held at the Institute on Thursday, Oct. 8, 1885, President Walker in the chair.

The minutes of the last meeting were read and approved, several new members were elected, and some matters of business were transacted, after which the president introduced Prof. W. T. Sedgwick of the Institute, who read a paper on "Relative Poisonous Properties of (Illuminating) Coal and Water Gas."

Prof. SEDGWICK said: The recent extensive employment for illuminating purposes of the so-called "water" gas, derived from the decomposition of steam by the action of incandescent coal, and enriched with the vapor of naphtha, has excited a vigorous discussion of the question whether this gas is or is not more dangerous to the public health, when distributed for the purposes of illumination, than the ordinary "coal" gas derived from the destructive distillation of bituminous coal. Up to the present time, although opinions, chiefly a priori, have been freely expressed in the affirmative, and especially in the negative, in answer to the question, very little experimental evidence has been available.

In view of the possibility of the general substitution of water gas for the coal gas now in common use in Massachusetts, the question has assumed a large public importance, and, accordingly, under the instruction and direction of the State Board of Health, Lunacy, and

Charity (Sixth Annual Report, 1884, Supplement), an investigation was undertaken by Prof. W. R. Nichols and myself, in the hope of obtaining facts which might serve to answer the question.

Illuminating gas, as ordinarily supplied to consumers, is a poisonous gas, whether it be made from coal, wood, or other organic substances (coal gas, wood gas, etc.), or derived from coal and water by their action upon each other at high temperatures (water gas); but it is never a single gas of uniform composition. It is always a mixture of several gases, and it is the mixture known as coal gas which must be compared with the mixture known as water gas. The composition of these mixtures, as might be supposed, is not always exactly the same, but varies somewhat from day to day in the case of the same kind of gas; and very considerably in the case of the same kind of gas made in different places by different methods. These variations of composition must not be lost sight of, but they are generally within narrow limits, so that the expression "coal gas" or "water gas" stands for a tolerably definite substance or mixture.

It is freely admitted that both gases are poisonous; but there has been hitherto no general agreement as to their relative poisonous properties. This is the more remarkable because the principal poisonous constituent is unusually well known, and its properties have long been recognized. For, whatever importance be attached to the physiological actions of the other constituents of coal and water gas, it still remains true that the only really poisonous substance which is present in any considerable proportion, in either gas, is carbonic oxide.

All the gases in these mixtures (excepting oxygen, which is occasionally present in very small proportion) are irrespirable, i. e., they cannot supply the place of oxygen for breathing purposes, and, if breathed undiluted, will produce speedy death from suffocation.

But besides this negative power, which it shares with the other constituents of illuminating gas, carbonic oxide is conspicuous for poisonous properties which are peculiarly its own. It exerts, for example, a special direct action upon the living blood-cells of the animal body, depriving them of the power of performing their normal functions, and, if present in sufficient quantity, speedily undermines the functions of the whole body.

On the assumption that carbonic oxide is the only essentially poisonous substance in both coal gas and water gas, it might seem

that the question which we were endeavoring to answer could have been settled by experiments upon carbonic oxide itself. Investigations of this sort have, indeed, been made by a number of experimenters, and the only point of disagreement between them is as to the effects of very small amounts of carbonic oxide. It is agreed that carbonic oxide is a powerful poison, but it is still a question whether or not the smallest quantities are wholly ineffective.

For our purposes, however, there could be no doubt as to the desirability of experimenting with the two gases as they actually flow from the pipes of the companies which manufacture and distribute them. This was the more necessary because it has been suggested that other gases beside carbonic oxide, occurring in illuminating gas, may be operative in making up its total poisonous quality. We have given the suggestion its full value, and have arranged our experiments accordingly. At the same time, the close resemblance of the symptoms observed in poisoning by illuminating gas to those produced by carbonic-oxide poisoning should have due weight, as should especially the results of Gruber,* who removed the carbonic oxide from illuminating gas, and then mixed the purified gas so obtained with air in various proportions. In atmospheres of this kind, containing sometimes as much as eleven per cent of the gas freed from carbonic oxide, animals (mice) remained for hours, exhibiting merely some stupefaction, and quickly recovered when taken out.

Without denying, therefore, to the other constituents their proper physiological effects when breathed with air, in a mixture of which they form a large proportion, it is probably true that carbonic oxide is the only component of illuminating gas whose poisonous qualities are at present of practical importance to the public health.

According to the report of the State Inspector of Gas and Gas Meters for Massachusetts for 1884, the average amount of carbonic oxide in a number of specimens of coal gas was 5.53 per cent. The amount of carbonic oxide in the water gas at Middletown, Conn., at the time of the experiment, was 30.5 per cent, and at Athol, Mass., 29.2 per cent.

In the selection of rooms in which to perform the experiment, it was our endeavor to imitate, in a general way, sleeping-rooms of medium size as they actually exist. In no case were windows made

Archiv für Hygiene, I (1883), 168.

to fit more tightly than usual; the "crack "above the threshold was always left open; while, on the other hand, no unusual holes or other escapes were allowed to remain; so that, in this respect also, we reproduced, as far as possible, the conditions of an ordinary sleepingroom, whose doors and windows are left closed. The rooms, in fact, gave the impression of "close," but not unusually tight, apartments.

some

All the work upon coal gas was done in a room in Newton Centre, while the work upon water gas was done in other rooms, of it in Middletown, Conn., and some in Athol, Mass. But in all cases, whether of coal or water gas, the supply for the experiments was taken from pipes of the local company, and allowed to escape into the apartments through ordinary burners supplied by the local gasfitters, and connected with meters for the registration of the inflow.

The room in Newton Centre was built in a barn, and made tight by partitions of matched boards. The ceiling was matched and double, with an intervening air-space. The walls were single on two sides, and double on two, and of three-fourths inch boards, matched. The floor was double, and tight. Overhead was an empty loft; underneath was a cemented cellar; and the room, being partitioned off in a corner of the barn, was separated from the barn proper by the single partitions,- from the outside by the single partition, the airspace, and the ordinary wall of the barn. There was one window (about five feet by three) admitting light from without, and two long but narrow windows were built into the partitions for convenience of observation. They fitted into casings in the usual way. One door, of the ordinary size, served for entrance, and, when closed, fitted somewhat loosely, leaving a narrow crack beneath. The dimensions of the room were as follows:

It contained two shelves and one two-story pine table. The gasfixture was a cheap, plain, four-arm chandelier hanging from the middle of the ceiling. A meter was connected, and located for convenience in the barn, where the observer could easily read it at any time. One of the rooms in Middletown, Conn., contained a little less than 2000 feet, free space, and was furnished with one very large