This certainly looks like getting change for a pound note, with the addition of a certificate for practical benevolence. This is not charity--it is traffic; and it is trafficking, on the most favourable terms, with the services of the medical profession. It is possible to pay too much for an article, though no money may change hands; and it appears to me that this article of medical attendance and medicine is purchased by the sacrifice of independence, and the consequent loss of self-respect, which is the greatest loss which any man can sustain; for, when a man loses self-respect, there is not much left. When a man is a pauper, not from necessity, but from choice, he is gravitating towards a condition from which the element of choice is eliminated-a condition of necessary pauperism. Every scheme which has a tendency to pauperize, however benevolent its title may be, should be regarded with more than suspicion; but a similar scheme, based upon "thrift," commends itself to every right thinking man, the only question being, Is it practicable?

I believe that there would be no great difficulty in successfully introducing the Provident Dispensary scheme into Glasgow ; but it would require a distinctive agency. Various administrative arrangements have to be made before the scheme can be placed upon a basis sufficiently solid to commend it to public confidence; and pecuniary aid would be necessary until a sufficient number of provident members had joined to make it self-supporting. There are, within the district of Glasgow, at least 20,000 men, most of them heads of families, in connection with the various friendly societies, who are fully alive to the advantages of medical relief, on mutual assurance principles, and who are thoroughly acquainted with the practical working of such societies. Many of these would, I doubt not, favourably regard the introduction of any such scheme, and would give it their hearty support. Indeed, the co-operation of this class would be essential to the success of the scheme; and, were it once set agoing, I believe that it would be best to leave the carrying of it on in the hands of the provident members themselves. The success of the great provident societies, here and elsewhere, is a sufficient guarantee that those immediately interested can best manage their own affairs, and this class like to do so in their own way.

Would the initiation of this scheme be worth the trouble and expense? I think it would, on various grounds and for many reasons. I shall confine my concluding remarks to one, not the

most important one-viz., its relation to the Public Health. As members of society, we must confront these 3,600 untended deathbeds, and these 32,000 uncared-for sick beds. Do what we will we cannot shirk our obligations. We are responsible, probably to a greater extent than we are willing to admit, for both the misfortunes and the vices of this class, and also for their resulting

The most expensive mode of performing our public duties is neglecting to perform them; by-and-by the tax-gatherer will call and we will require to pay, with interest and expenses. If the head of a family dies through public neglect, the account is not settled when the undertaker and gravedigger are paid. There may be another account to settle, on behalf of a neglected family, from the poorhouse, the prison, and perhaps from the hangman. The ramifications of such matters are wide, and may extend so far that we are unable to trace them. Neglected disease of any kind is necessarily a serious matter; but more especially is it so with neglected disease of the infectious and contagious class. Such diseases could be easily rooted out, so that they would finally disappear from our West-End houses; but this is not enough. There is no safety for the West End so long as the East End is neglected; no safety for the rich so long as disease is allowed to run its course among the poor. Every man is his brother's keeper, and no one is rich enough to pay for a substitute. Obligations of this kind cannot be delegated. So long as the health of the poor is neglected, the health of the rich is not safe; and the connection between the hovels of the one and the villas of the other is much closer than most of us imagine. Lazarus, in stern reality, sits at the rich man's gate, and the dog that licks his sores may lick the children's hands. Human nature is stronger than the order of a mistress; so that a maid may, on her afternoon out, nurse a little brother or sister sick of scarlatina or diphtheria, forgetting that she may carry disease and death to the family whom she serves. Who can blame her? Was she warned, while tending the sick child of her mistress, against carrying infection to the little ones of her own family?

Our only mode of safety from the ravages of epidemic diseases consists in attacking them in the centres from which they spread; but this can never be done by medical officers of health and sanitary inspectors alone. The entire population must be brought under medical surveillance, and I can see no better mode of doing so than by the promotion of some such scheme as I have laid before

you. The registration of disease would then be a possibility, and what are now regarded as the day-dreams of sanitarians, would gradually assume the substantial form of realities.

XII.-On Improvements in Gas Stoves. By JAMES ADAMS, M.D., L.R.C.S.E., F.F.P.S.G., Late Examiner in Chemistry, Fac. Phys. and Surg., Glasg., Late President of the Glasgow Medico-Chirurgical Society, &c., &c., &c.

[Read before the Society, March 17th, 1880.]

TWENTY-FIVE years ago I read to the Glasgow Medical Society a communication on heating by gas, and exhibited a stove made to my design. In my belief that stove surpassed anything since open to public observation. But it was liable to drawbacks, which I then failed in overcoming, and I put aside my conception. I retained, nevertheless, the desire to see it realized, being sensible that I had made a substantial step in advance, and I have kept myself informed, and noted with interest all that has since been done in this connection. About eighteen months ago I re-entered with zest upon a practical investigation, feeling assured that the principles were sound that I had assumed for my guidance, and had practically embodied in my infant conception. I will now bring under your consideration a practical illustration of those principles.

Coal gas is not of uniform composition. It is a mixture of gases and of vapours, the number, qualities, and proportions of which vary in every locality where coal gas is manufactured for public use. Its most abundant constituents are compounds of carbon and hydrogen-the latter forming the bulk of the mixture. However carefully manufactured, impurities are always present, which, together with the gaseous waste products of combustion, should never be permitted to accumulate in the air of dwelling apartments. When coal gas is burned its constituents are transformed into other gases and vapours. On this point there is much popular ignorance. Because no smoke, and no marked odour may be perceptible, it is assumed that the combustion has left behind it nothing injurious. There is a hazy conception that perfect combustion means something like practical annihilation. But in

point of fact, the invisible, mal-odorous, inflammable gas, has been merely transformed into invisible, non-odorous, non-inflammable gas. The carbon has united with oxygen of the atmosphere, and formed carbonic acid-a deadly poison if inhaled pure-and the hydrogen has united also with oxygen of the air, and formed watery vapour, whilst a large quantity of nitrogen has been set free from the air. But if combustion has not been perfect, there is formed, in addition to carbonic acid, another still more poisonous gas, called carbonic oxide. The common sense deduction is that gas stoves should be provided with flues to carry off the waste products of combustion into a chimney. It should scarcely be necessary to add that, where a stove is substituted for a grate as a means of heating an apartment, there should be retained the open chimney, or other means of proper ventilation which the open fireplace usually ensures.

The amount of light obtained by the combustion of coal gas varies according to the construction of the burner employed. The same gas which gives a pure yellow smoky flame when burned with a "rat tail" jet, is brilliantly white when a union jet is used, still brighter with a common argand, better still with a Sugg's argand; while in the latest street lamp introduced in Paris, and of which several are now under observation in this city-we seem to have reached a perfection that rivals the electric light. The production of heat-which as a force is identical with light-is quite as much influenced by the form of burner employed. And as the phenomena of light require to be considered with reference to the luminous rays, the chemical rays, the coloured rays, &c., so do the phenomena of heat require to be considered with reference to dark rays, visible rays, and other components or characteristics. Thus the several properties through which heat is communicated---viz., conduction, convection, and radiation-have each their special value and appropriate use, and ought to be carefully studied, so as to best ensure the maximum intensity of each property as well separately as in combination. A kettle over the fire is boiled partly by convected heat contained in the diffuse mass of flame and smoke ascending the chimney, and partly by radiant heat emitted by the solid incandescent coal underneath. But a leg of mutton placed in front of the same fire receives no heat whatever from convection, but is roasted exclusively by radiant heat emitted chiefly from the red-hot coal. A very small proportion only of radiant heat is emitted by the flame and smoke. By accurate

observers it has been determined that about three-fourths of the heat from an open fire is convected heat, nearly all of which passes up the chimney, leaving only a fourth to be utilized as radiant heat. When coal gas is used as fuel, and the ordinary jet for lighting purposes employed, the convected heat generated amounts to 84 per cent., or five-sixths of the whole, and only 16 per cent., or about one-sixth, is given out as radiant heat. When the Bunsen burner, in any of its forms, is employed, the heat generated is nearly altogether that of convection, about 6 per cent. only consisting of radiant heat. The difference in the proportion of radiant and of convected heat, emitted by the same gas by a mere change in the method of combustion, depends on the presence of solid carbonaceous particles in the luminous flame. This question has been thoroughly worked out by Tyndall, and the results are recorded in his "Contributions to Molecular Physics in the domains of Radiant Heat." Using an apparatus of sensitive precision, he found the radiation from the luminous gas flame was fully two-and-a-half times that from the non-luminous flame. The degree of force-not the degrees of temperature-in the luminous flame was 30, and the radiation fell to a force of only 12 the instant the flame became non-luminous. But, by introducing solid matter, the radiation originating in the non-luminous flame became so intense that a spiral of platinum plunged in the flame brought up the index to a force equal to 200-that is, there was instantly generated an amount of radiant heat more than 6 times that from the luminous gas flame, and more than 30 times that of the non-luminous flame. "It is mainly," says Tyndall, "by convection that the hydrogen flame dispenses its heat; though its temperature is higher, its sparsely-scattered molecules are not able to cope in radiant energy with the solid carbon of the luminous flame. The same is true for the flame of the Bunsen burner. The moment the air (which destroys the solid carbon particles) mingles with the gas flame, the radiation falls considerably. Conversely, a gush of radiant heat accompanies the shutting out of the air, which deprives the gas flame of its luminosity. When, therefore, we introduce a platinum wire into a hydrogen flame, or carbon particles [or platinum, or various other solids] into a Bunsen flame, we obtain not only waves of a new period, but also convert a large portion of the heat of convection into the heat of radiation.”

To obtain in a practical form the means of converting the heat