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Dec. 15, 1876.
Newcastle Chemical Society.-President's Address.
The following Report of the Committee was read:
In commencing the ninth session of the Society the Committee find that there is but little on which they need specially remark.
The number of members remains about the same, in spite of additions to the list of new names, these being about balanced by withdrawals and removals from the district. The Committee would here observe that considerable trouble is caused by gentlemen who, without giving any formal notice of withdrawal, neglect to pay their subscriptions, and take no notice of the applications of the Treasurer. As every member, so long as his name remains on the list, causes to the Society a certain amount of trouble and expense, the Committee feel that it would" be only fair on the part of these members to signify to the Secretaries their desire to withdraw.
The deficit, irrespective of arrears of subscriptions, has increased during the last twelve months, and the Com. mittee will probably have to consider two alternatives-a less extended report of the discussions upon papers, or an abandonment of the refreshments which have been for some sessions provided at ordinary meetings; unless, indeed, some source of increased revenue can be suggested, e.g., an increased list of members.
The Committee are, of course, hardly in a position at present to express a decided opinion on this very important point, but they hope to bring it before an early general meeting.
In conclusion, the Committee appeal to all members to assist them in their efforts to render the ensuing session a successful one, by personal co-operation. It will be seen, by referring to the Transactions, that the bulk of the labour in this respect has been borne by members whose names recur but too frequently, and the Committee would earnestly impress the desirability of a change in this respect.
deleef in connection with this subject, and with the theory which he promulgated more than seven years ago, that "the physical characters of a radicle are periodic functions of its atomic weight." Having pointed that out, he proceeds to remind us that the characteristics which are assigned to gallium are precisely those which he assigned seven years ago to the metal which he then designated Ekaluminum," and which he argued, on purely mathematical grounds, ought to exist. Now, whether this is merely a more or less interesting coincidence, or whether it is really the climax of a process of pure mathematical reasoning, by which we shall be able to predicate radicles which ought to exist, we can hardly yet say. When Ekasilicium," of which he has also predicted upon purely mathematical grounds the existence, is discovered, and discovered existing, as he says it will exist, in company with arsenic, we shall then, I think, have a rather wider basis for induction. Still we must admit that the coincidence, if a coincidence it be, is a very interesting one, and one well worthy of being recorded. Passing from this to a closely-allied subject, I may remind you of the interesting paper, produced in the course of last year by Prof. Henry Wurtz, on, as he entitles it, "A New System of Geometrical Chemistry." If you have read that paper I am sure you will agree with me that the greatest credit is due to him for the untiring labour which must have gone to the collecting of the data for his system. Every specific gravity which has ever been published on reliable authority for any compound appears to have been collated by him; and in a not less notable manner is his ingenuity displayed in putting together these data, and in inducing eventually three laws, which I should certainly advise you to read for yourselves.
Passing from the applications of the purer and higherfor I suppose we must say the higher-science of mathematics to our experimental data, we come to one or two subjects upon which purely experimental data, and data of very considerable value, have been afforded to us during the past year. Mr. Thomas has produced two papers-or I should rather more correctly say three-of the very highest interest, on the "Gases Occluded by Coal." I will not detain you by going into details which you can but I cannot help remarking that they are of exceeding interest, as additions to our knowledge on the subject, of which we knew little or nothing previously, with the exception of the somewhat imperfect researches of Von Meyer,-researches imperfect, not because there had not been every care bestowed upon them, but imperfect, as I cannot but think, from the method employed in carrying them out. I may remind you of his process for collecting these occluded gases, consisting in heating a flask filled, partly with the coal under examination, partly with re
GENTLEMEN,-Before commencing the Address, the deli-read for yourselves in the Journal of the Chemical Society, very of which custom imposes upon me, permit me to thank you very sincerely for the honour you have done me in electing me as your President-an honour which I appreciate none the less that I could most sincerely have wished it had fallen upon some other member of the Society. One of the principal difficulties which a President must experience on such an occasion lies in the selection of topics; not but that in the range of our science there is an abundance on which to speak, to more or less profitable purpose, but the difficulty is really to select amongst the mass of materials which present them-cently boiled water, and collecting the gases evolved also selves at the very outset. We enter to-night upon our ninth session. I may assume then, I think, that our raison d'être is abundantly demonstrated, and it is hardly necessary that I should occupy your time in considering what are the functions of a Society like our own, and how far we discharge them. When we turn to the other alternative, a more or less systematic review of the progress of our science during the last twelve months, we experience at once the difficulty of selection. The Journal of the Chemical Society, as most of you know, is made up almost entirely of abstracts, condensed of necessity into the very smallest space; and yet, during the six months ending last June, it occupied no less than 998 closelyprinted pages. We may, however, select from among the varied subjects which have occupied our little world during the last twelve months some sufficiently prominent to afford materials for a few minutes consideration.
We have no particularly sensational-if I may permit myself the term-discovery to record. The nearest approach to that, perhaps, is the further examination by M. de Boisbaudran of his new metal Gallium; and here I may remind you of the reclamation made by M. Men
over water. I need scarcely point out to anyone who has even a limited experience of gas analysis the imperfections of this method, in regard both to evolution and collection of the gases. The more perfect method employed by Mr. Thomas, of heating in a vacuum produced by the use of a Sprengel pump, has yielded results very different from those of Von Meyer, and which, when the series of researches is completed, cannot but be of the greatest value to all who are concerned with the technical as well as theoretical consideration of the subject.
Mr. Galloway has dealt with a kindred subject—“ The Effect of Coal-Dust upon the Productions of Explosions in Coal-Mines." Many of us, I believe, were present at the exceedingly interesting demonstrations which Mr. Galloway gave, some two or three years ago, in this room, in connection with his former research upon the effect of a sound-wave on the passage of flame. This latter subject, which Mr. Galloway has investigated, is equally closely connected with the well-being of coal-pits, and I may therefore state briefly the results at which he has arrived. It might have been very well doubted-and it is, in fact, even now to a certain extent doubtful-how far dry coal
Newcastle Chemical Society.-President's Address.
dust per se is capable of producing, when unmixed with fire-damp, a mixture with air which can be termed explosive in the ordinary sense of the term. Experiments are in progress with the view of determining this point, and it is not impossible we may be able to lay some of the results before our Society during the present session. But what Mr. Galloway has shown us is, that where, in addition to coal-dust, there is present a very small proportion of damp, which can hardly show itself by a cap on the miners' safety lamp, that very small quantity is equal to the formation of an explosive mixture. A quantity, ranging from 1 to 2 per cent of fire-damp, when mixed thoroughly with the air of the mine and coal-dust, and passing over a naked light, is capable of producing an explosion, or, on a small scale, an exceedingly rapid combustion. Clearly these experiments bear upon the everyday work of our own district, and, as such, we are indebted to Mr. Galloway for his painstaking investigation of an exceedingly important question.
I come now to a set of experiments which possibly many of you have already read in detail, and which partake alike of the purely scientific and of the practically interesting character. I allude to the researches which Dr. Tyndall has conducted, after his well-known patient method of experiment, on the relation of the optical deportment of the atmosphere to the phenomena of putrefaction and fermentation. It is so obviously impossible to give more than the very briefest abbreviation of these results that I must refer you for details to the paper in the Transactions of the Royal Society; but the cardinal experiment, of which all the others are variations, and upon which the proof of Prof. Tyndall's proposition mainly rests, I think I shall be able to explain in a very few minutes, with the assistance of the working model on the table. I need not remind you, I suppose, of the former researches of Prof. Tyndall in this same direction. I need not point out to you how he has shown that the purity or otherwise, as regards suspended matter, of the atmosphere can be determined rapidly, easily, and certainly, with the assistance of a sufficiently powerful beam of light. I need not remind you of the "motes in the sunbeam," which Prof. Tyndall has happily adopted as the term to designate the somewhat indefinite suspended matter of the atmosphere, but I may just illustrate by experiment his beautiful demonstration of the probability of the organic character of at any rate by far the larger portion of that suspended matter. If we turn on this lime-light, and bring below its track, marked out in the air of the darkened room, a Bunsen burner, you see the appearance of smoke produced by the heated air traversing the light track, and destroying the suspended matter. Now, extending the application of this process, Prof. Tyndall has constructed an apparatus, of which we have a rough working model before us on the table. We have a box which can be closed practically dust-tight. We have the means of transmitting a powerful beam, such as we have just been using, from side to side of the box, and so observing whether there is any difference in optical deportment of the air inside the box and the air outside it. We have, of course, in front the means of observing this; and we have a small door fastened dust-tight, by which we can keep the box in communication with the external atmosphere, or not, at will. Lastly, we have an aperture above through which we can pass the point of a pipette. We varnish the sides, top, and bottom of the box with a mixture of glycerin and water, to act as a mote trap and detain the suspended matter which settles upon it. Then, closing the different apertures of the box, we leave it to itself for a few days, and from time to time examine it with the help of such a beam (or a stronger one), as you have just seen. After a time the whole of the motes in the little portion of included air have settled on the sides and bottom of the box. The track of the beam of light can no longer be distinguished inside the box, although we can see it easily before it enters and after it emerges; and now our air is optically pure, and in a condition to com
mence experimenting with. Then, passing through the pin-hole the pipette, we fill by its means the test-tubes which you see are cemented into the bottom of the box with an infusion of any animal or vegetable matter you choose. We abandon these, after heating them to rather above boiling-point by a salt-bath below, to their own devices. Now, Dr. Tyndall has repeated this experiment with some 600 different test-tubes containing every variety of infusion, and he has found that when the tubes have heen heated to boiling in contact with the mote-free air, and then abandoned to themselves, they have never in any one case undergone the action which we style putrefaction, and after they have remained for some time unputrefied the mere opening of the box is sufficient in two or three days, by the action of the motes in the air from outside, to initiate with unerring certainty the phenomenon of putrefaction. I cannot see how we can logically come to any other conclusion than that this phenomenon, and, probably, its close ally fermentation, depend upon the action of what Prof. Tyndall calls motes. Others perhaps would give to them the name of germs, but if we call them motes we commit ourselves to nothing except that the suspended matter of the atmosphere is closely connected with these phenomena. I should weary you if I were to go into detail on the different forms in which this experiment has been repeated. You will find them described at length in the original paper, and the more you read the more I think you will be possessed with a sense of their beauty. But there is one part of the experiments which is so exceedingly interesting, both theoretically and practically, that I must attempt its description. Let another set of tubes be connected with the sides of this box; let them be filled with a putrescible fluid; let that undergo the action of putrefaction; and when that action is at its highest, and when the gases evolved during it have completely filled the box, let the lower tubes be also filled with a putrescible fluid, by means of the pipette. Let that be boiled and abandoned to the action of the gases evolved during putrefaction, and in no case will it undergo putrefaction. It may be in the fullest contact with the most nauseous gases from putrefaction, but as long as only gases are brought into contact with it, it will not putrefy; but let the smallest fraction of matter already putrefying be introduced into the "protected" fluid, as we may term it, and putrefaction is absolutely certain. I should probably spend too much time if I were to go into details as to the practical bearings of this experiment, but I think you will see the analogy which Prof. Tyndall points out between this and the not unfrequent case of sewer gas causing zymotic disease is not a far-strained analogy after all. When we endeavour to trace a connection between sewer gas and zymotic disease we are constantly met with this objection-"If it is really the dreadful thing it is said to be, why is there not disease in every house in which it may be smelt?" Not to dwell on the probable necessity for a favourable nidus as well as for the germ, in order to initiate that class of disease, I may point out that here the sewer gas, instead of being actually the cause of disease, simply tells us, by its unmistakable smell, that communication is established between the drain and the house,-it may be to bring in only comparatively innoxious gas, but it may be to bring in a current of gas laden with zymotic poison, which we may liken to the motes in this box. And the more you consider this case the more you will see the close bearing this experiment of Prof. Tyndall's has upon a matter which concerns our public health in the closest degree.
I should not leave this subject, or, if I did, I should leave it exceedingly incomplete, if I did not refer to Dr. Frankland's elaborate paper on the examination of potable waters. I will not detain you by enlarging upon the vexed question of water analysis, but there one or two points in the paper which are of sufficient interest to be worth remarking on. Probably many of you have read all that is there said of the case reported from Switzerland, of the conveyance of typhoid fever for very nearly a mile in dis
Dec. 15, 1876.
Present State of the Iron Manufacture in Sweden.
tance through a water-supply. The two experiments cited, are so interesting and so ingenious, and lead to such exceedingly important practical results, that I may go into them a little in detail. In the first instance, to establish the fact that the source of the water-supply from which the contagion was supposed to have been derived in the first instance was really in connection with the public wells, which were supposed to have conveyed the disease, the following experiment was made:-Some hundredweights of common salt were put into the suspected water-supply, and in the course of a comparatively short time the quantity rose in the well water to sixteen or eighteen times the normal amount. I do not think we need any further proof that the two sources of watersupply were in complete connection; but to supplement that experiment, and to trace the effect of the filtration of the water through a very considerable length of porous soil, a few hundredweights of flour, sufficient to make the water thoroughly turbid, were thrown in and stirred into the suspected source. Although the salt had traversed the connecting strata not a trace of the flour could be detected, either by chemical or microscopic examination in the contaminated well water. Mechanical filtration then had been quite sufficient to remove this suspended matter, but had, nevertheless, been insufficient to remove the subtle typhoid infection. Now, that that proves positively that infection is due to a "germ," I do not say: it will be evident that the phenomenon is equally easily explicable, whether we suppose it to be due to an infinitesimal germ, so minute as to pass the filtering-bed in such way as an infinitesimal particle-say of sulphate of barium-passes a filter-paper; or whether we suppose it to be due to a definite soluble poison existing in solution; and therefore capable of passing any filter, no matter how effective. On either ground the results seem equally explicable; but they point clearly to one fact-that no process of mechanical filtration, however complete, can really be trusted to purify water which has once received the infection of the diseases which we group together for convenience under the name of zymotic.
(To be continued.)
NOTICES OF BOOKS.
Science in Sport made Philosophy in Earnest, being an
THE author of this work tells us that his original design
the whole of the scientific matter in the book in order to
bring it into harmony with the existing state of knowledge. For the story with which the instructive portion of the original work is interwoven he has found it desirable to "substitute a quite different, much slighter, less intricate, and perhaps more probable tale."
This work, therefore, is a story, or, if the reader will, a novel made the vehicle of physical instruction and interspersed with lectures, or, as they are now called, "conferences." The author expresses a hope that no one will find in the narrative in itself so much attraction as to "skip" the graver portions of the book. How far he is right in this respect, considering the truly canine appetite with which fiction is devoured by the public, may perhaps be doubtful. Were we an authority on such points we might question the raison d'être of Miss Ryland and her sister-gossips-characters not wholly new in literature even though they combine with their morbid love of scandal the new mania for "woman's rights." They are
introduced without necessity; they neither exert any influence on the progress of the story, nor are made to illustrate any physical principle, and they soon disappear, having merely served to add a few pages to the bulk of the book. The science of the book, after a careful examination, appears to us accurate, and it is certainly illustrated with no small felicity. Exception may, however, be taken to certain remarks on colours in the sixth chapter. Thus the author asserts that "the supposed effect of scarlet (dazzling the eye) is explicable by its comparative rarity in nature, and I doubt not but that if all the green and red changed places we should be as much attracted by green as we now are by red, and would attribute to it the same exciting effect; while the repose you speak of as belonging to green would seem to belong to the scarlet foliage to which our eyes would be so much accustomed."
We are at a loss to conjecture upon what facts this singular opinion can be based. Scarlet is, indeed, somewhat rare in nature, but in dye works it is as plentiful as is green, and the examination of pieces of scarlet cloth to ascertain whether they are correct to shade is found very fatiguing to the eyes. If scarlet or even magenta swatches are regarded for a long time, and fixedly, the eye becomes temporarily incapable of judging of their exact tone. The observed effects of light of different colours upon vegetable life clash also with Mr. Routledge's view. The fifteenth chapter, in which the author treats of work and its measurement of energy, and explains the meaning of the foot-pound, may be advantageously read, not merely by children, but by many of mature age who entertain somewhat hazy notions on this subject.
We hope this volume may meet with such a reception as to induce the author to extend his plan and produce a companion volume dealing in a similar manner with some of the many scientific questions not here included.
The Combined Note Book and Lecture Notes for the Use
THIS book contains a table of the elementary bodies, with
Then follow a number of leaves arranged for taking lecture notes, with certain headings to be filled up.
The last part of the book, as the author tells us, "contains all the best known methods for the preparation of the various elementary and compound substances," at least, as far as the non-metallic elements are concerned. He has" purposely left out any explanation as to the conshould be done by the student himself, either from his dition under which they are prepared, preferring that this lecture notes or text-books." By this method, it is without any cramming." Finally there is a table of said, he gains "two objects, viz., good and sound work tests for the most important acids.
The work, we are told, is "not in any way supposed to
take the place of a text-book, but to act as an adjunct to it."
On the Present State of the Iron Manufacture in Sweden.
The Late David Forbes, F.R.S.
iron-ore are remote from the more extensive forests and peat beds. The ores consist chiefly of magnetite and hæmatite. In some districts, such as Gräsberg, these two ores are so much mixed together that it is not easy to decide to which species samples ought to be assigned. These ores belong to the primitive or Laurentian formation, and generally occur in stratified masses, having the same strike and dip as the surrounding rocks. They may be arranged in three classes, those rich in quartz, those abounding in magnesia, and those containing a notable amount of manganese and interspersed with sulphides. The latter class, when their proportion of sulphides is not considerable, have been highly valued for the preparation of steel. The amount of iron ranges from 30 to 70 per cent. They contain, in general, little phosphorus; those of Dannemora having only 0.003 per cent, and those of Persberg 0.05 per cent. The Grängesberg ores, however, have been known to contain even 15 per cent, being intermixed with apatite, whence it has been proposed to submit them to a preliminary treatment in the wet way utilising the apatite as superphosphate. Titanium, which is in some cases abundantly present, is an undesirable ingredient, as it renders the process of reduction more difficult and occasions a great waste of charcoal.
The total amount of ore raised in Sweden during the year 1874 from 696 mines was 21,692,998 centners, equal to 922,524,000 kilos. The number of persons employed was 7497. The book is illustrated with a large map of the mining districts of Southern Sweden, and contains a tabular view of the composition of Swedish iron-ores, inconveniently arranged. The continental method of using for decimals figures smaller than those denoting whole numbers has been followed, to the tribulation of the readers' eyes. The value of the work to practical men would also have been greater if the weights of metal, ore, &c., produced, exported, &c., had been calculated into tons instead of kilogrms. Apart, however, from such mere defects of form and from certain expressions, which cannot be considered idiomatic English, this publication will be highly interesting to all persons connected with the iron manufacture.
DAVID FORBES, F.R.S.
THE saddest duty of the editor of a scientific journal is that of recording the death of eminent labourers in the field of science. In the too early death of David Forbes science has been deprived of one of her most zealous and hardworking devotees, while we have also to mourn the loss of a valued friend. Few men have enjoyed greater facilities for acquiring a knowledge of nature by personal observation in different parts of the world than David Forbes, and armed with dauntless courage and indomitable perseverance he made the most of his opportunities. Those who have heard him read papers at the Chemical or Geological Societies, or who have been present when he has taken part in a discussion know how thorough and how vast was his knowledge. It is to be hoped that the manuscript notes which he had made with the view of elaborating them in future years will not be entirely lost, but that they admit of being arranged and published in some form or other, though they would have been of infinitely higher value had they received the addition of those still larger stores of knowledge which are now entirely lost. In 1858 David Forbes was elected a Fellow of the Royal Society, and at the time of his death he was senior Secretary of the Geological Society and also foreign Secretary of the Iron and Steel Institute, a post for which he was eminently fitted. His reports on the iron and steel industries are most valuable additions to technical scientific literature. Many excellent papers
from his pen have appeared in the CHEMICAL NEWS; amongst them we may mention those entitled: "Application of the Blowpipe to the Quantitative Determination or Assay of Certain Metals;" "Some Points in Chemical Geology;""The Preparation of Lime Crucibles for Great Heat;""The Composition and Metallurgy of Some Norwegian Iron-Ores ;” and “The Microscope in Geology."
He died at the age of 49, and was buried at Kensal Green Cemetry on Monday last. The Director General of the Geological Survey and the Presidents of the Chemical and Geological Societies were amongst those who were present at the grave.
The following_account from the pen of Mr. F. Field, who was one of Forbes's intimate friends, renders it unnecessary for us to refer at greater length to the scientific results of his journeys and labours :
"The death of David Forbes, a man at once chemist, geologist, and mining engineer, must have excited deep regret throughout the scientific world. Few men amongst us have travelled so much or have had the same opportunities of research. From Finland to the South of Spain in Europe, from Cape Horn to Panama in the western continent of South America, did his journeys extend, and his museum bears ample testimony to the energy and zeal with which they were prosecuted, embracing, as it does, rare and sometimes unique specimens, mostly collected by himself, of all branches of natural history from nearly every part of the globe. Only those who have travelled over the bad roads and mountainous districts of South America can appreciate the difficulty of transporting specimens from the interior of the country to the coast previously to their shipment for Europe. Perhaps a few reminiscences of David Forbes when a comparatively young man may not be altogether devoid of interest. I first met him in the Port of Coquimbo, Chile, in 1858, and was surprised at the rapidity with which he had acquired the Spanish language. He was a thorough cosmopolite, and seemed as much at home with the Chilian miners and smelters as if he had been born among them, entering into their peculiarities, accommodating himself to their mode of life, and making himself universally popular. Whilst most foreigners, Englishmen especially, on taking a journey to the various mines, require many comforts which they deem indispensable, and have, at times, almost a cavalcade of servants and mules, laden with provisions and bedding, Forbes, if the idea suddenly struck him, would take simply a single guide (and he often went quite unattended) and traversed the most distant portions of the Republic, with a rapidity and an amount of observation which were astonishing. Thus after being only a few weeks in Coquimbo, he had explored the Higuera, Tamaya, Arqueros, Andacollo, Ovalle, Tambidos, and nearly every other mineral district of importance, knowing them better than most foreigners who had resided in the country many years. I remember on one occasion he determined to make the journey from Coquimbo to Copiapó on horseback, taking with him but one servant and trusting for provisions on the way as best he might. The road is through a desert, where water is seldom obtainable, and should the horse founder far away from any habitation the consequences might be very serious. He seemed to think nothing of this or other contingencies, made the journey, and returned to Coquimbo a few weeks afterwards, fresher and better than ever. He had an iron frame, and in those days was perfectly insensible to fear. When he was staying with me some few months later, a gentleman fitted out a three-masted schooner, and purposed taking a long cruise to the Fijis and other islands in the South Pacific. Almost at a moment's notice Forbes offered to accompany him, and spent many months in that delightful part of the world. This may seem a trifling incident; it is only mentioned to show that while most of us take some time to consider, Forbes made up his mind instantly. In the Chile
Revolution of 1859 Forbes, with many other Englishmen, | CHEMICAL NOTICES FROM FOREIGN were my guests at the British Consulate. Although the revolutionary party were successful in the province of Coquimbo, the Government had the supremacy on the coast, and the port was strictly blockaded. The blockade was respected both by the English and French men-of
Forbes (I know not why) was determined to go to Bolivia. No person was allowed to leave the spot: the English steamer, on arrival, did not drop anchor, but moved slowly round the bay, depositing the mail-bag in the Chilian officers' boat. Forbes pleaded for a passage, but in vain. He was not the man, however, to be daunted by a refusal. He hired a small sailing-boat, and with only two men and a slender store of provisions left from a creek just outside the bay, by midnight, and made sail for Bolivia, leaving me the laconic lines- Dear Field, I have broken their blockade.-D. F.' I subsequently learned from him that the winds had blown him many hundred miles beyond the port of Cobija, and he had to beat back against heavy seas for more than a week. accomplished his purpose, but arrived, as may be supposed, half dead from fatigue and want of food.
"Although Forbes died at a comparatively early age, he had led in the half century the lives of at least three men. An intermittent fever he had contracted in Peru prostrated his strength greatly during the last few years of his life. I met him a month ago at the B.' Club, of which he was a member, and, although complaining of illness, he seemed to me more cheerful than he had been since his late heavy domestic affliction. I little thought when I wished him better that I had shaken hands with him for the last time.
"Hither Green, Kent,
December 12, 1876."
SULPHUROUS ACID AS A DISINFECTANT.
To the Editor of the Chemical News. SIR,-In the CHEMICAL NEWS (vol. xxxiv., p. 245), you reprint an article from the Lancet "On a Mode of Generating Sulphurous Acid for Use as a Disinfectant, &c.," by Mr. Keates, in which it is stated "that there is no ready, convenient, and easily controllable way of producing this valuable agent (sulphurous acid) in use at present;" and then Mr. Keates proceeds to describe a mode of generating the acid by the combustion of carbon disulphide, as if this method were a novelty.
I have used sulphurous acid generated exclusively from the combustion of carbon disulphide, as a disinfectant for rooms during a period of nearly seven years, and have in this way consumed 6 cwts. of the disulphide during the last six years. Years ago I advocated this mode of disinfection before the Society of Medical Officers of Health. I know that others besides myself have been in the habit of using it.
No special form of lamp is required. The requisite quantity of the disulphide may be placed in an ordinary porcelain or copper dish placed on a tripod, and ignited liquid may be easily and safely burnt. A much larger quantity of the liquid should be used than that named by Mr. Keates-280 grs. for a room of 1300 cubic feet capacity. This would generate only 1-50th per cent by volume of sulphurous acid in the atmosphere of the room. At least five times that amount should be burnt, so as to generate an atmosphere containing 1-10th per cent of the disinfecting gas.—I am, &c.,
with a match. In five minutes several ounces of the
St. Pancras, Middlesex, December 9, 1876.
Les Mondes, Revue Hebdomadaire des Sciences,
Report on Cremation, delivered to the Prefect of Police by the "Council of Hygiene and Salubrity" of the Department of the Seine.-The Commission consider that cremation would be free from all objections on the score of public health, but that its economy would be doubtful except furnaces were maintained in continual action, and that by rendering the chemical examination of the body impossible it would prevent the detection of murder by poisoning.
Note on Herbelin's Method for the Expeditious Assay of Cinchona Barks.-M. Dubois.-The author finds that this method, which consists substantially in treatment with ammonia, does not give satisfactory results. extracting the powdered bark with benzol after previous Quinine is scarcely soluble in benzol, though the two compounds have a strong mutual affinity.
Phenomena of Digestion with the Cockroach.-The digestive juices of insects are alkaline or neutral, never acid.
New Experiments with the Radiometer.-D. S. Stroumbo.-If during the night a candle is lighted before a radiometer of the same height, and placed at the distance of 20 c.m., it turns from the right to the left of an observer, placed so that the radiometer is between him and the candle. The following facts were observed :--First. Whilst the radiometer continued to turn slowly from the right to the left I placed my five fingers on the glass stem of the instrument, and kept them there: in an instant the radiometer turned in the opposite direction, i.e., from the left to the right wtth a greater speed, and continued to turn thus indefinitely. When I removed my hand the radiometer slackened its speed, and after having turned so for some time it stopped for a few moments, and then resumed its ordinary course from right to left at a slow speed. Instead of applying five fingers I applied only one, but with the same result. I interposed silk, paper, and effect was produced, as also when I surrounded the glass copper between the finger and the glass, but the same foot of the instrument with a copper ring, which I held by a silk thread. I placed my finger on a point of the glass from the circumference which the radiometer describes, support very near the base at a distance of 10 to 13 c.m. when the same phenomenon took place, as also when I placed my finger on any point whatever, situated below the circle described by the radiometer. If I placed my finger at a point above this circle the instrument was not If the finger is applied to the glass at a point of the circumference described by the radiometer, it stops after some oscillations, and remains at rest, but resumes its ordinary course as soon as the finger is removed. Second. The radiobrought its glass foot in contact with a bow of copper, meter being at rest in a rather dark part of the room, I which I held by a strong piece of silk or cotton moistened, turn. I let fall the bow, and the radiometer in a few and which I drew horizontally. The radiometer began to moments ceased turning. I caused to be constructed a radiometer with plain discs of mica, which did not turn if speaking, it was a sensitive instrument, with which the If it was not a radiometer, properly placed in the sun. following experiments were made:-(1) I rubbed the glass surface of the instrument circularly from right to left with rection, following the course of the paper. I rubbed in the silk-paper; immediately the disks turned in the same diopposite direction; immediately the disks changed their direction, still following that of the paper. The friction ceased, and the disks ceased simultaneously. The cause of this phenomenon is evident: the friction of the paper
affected, and continued its ordinary course.