CHEMICAL NEWS June 14, 1862. Royal Institution of Great Britain. and it is used largely in the process of soldering. For instance, it is employed for preparing tin plates when you are obliged to get the surface of the iron which you are about to tin in a perfectly clean state. You put it in a bath of muriate of ammonia, which dissolves off the oxides which are on the surface, and leaves the iron in a state for soldering. It is also employed extensively in making the more common salts of ammonia. There is a point in connection with this to which I would direct your attention. I want to show you the peculiar character of ammonium as a metal. Ammonia consists of one equivalent of nitrogen and three equivalents of hydrogen. There seems to be little analogy between this substance and chloride of sodium or chloride of potassium. Chloride of sodium, which is common salt, contains the silvery metal sodium; and chloride of potassium contains also the silvery metal potassium. There seems to be little analogy between a gaseous body consisting of one of hydrogen and three of nitrogen; but I am going to attempt to imprison this body, which consists of four equivalents of hydrogen and one of nitrogen, by amalgamating it with mercury. Here I have a saturated solution of this salt, chloride of ammonium, which chemists are compelled to think contains a substance having metallic characters, although it consists of these gaseous bodies, nitrogen and hydrogen. Here I have an amalgam, or a compound of mercury with sodium. Now, if I pour this amalgam of sodium and mercury into the chloride of ammonium, the sodium takes away the chlorine from that compound, and leaves the ammonium to combine with the mercury. This metal is NH. It is one of an evanescent character, and I must imprison it by holding it in the mercury in order to show you its presence. As the ammonium acts upon the mercury it will swell up. It is now swelling. You see it growing in bulk before your eyes. We have the ammonium imprisoned by the mercury, and enabling me to show you for awhile that this substance really has metallic properties, although it will soon dissipate again into the gases of which it consists. You see that it has formed an amalgam, as the sodium did, but, from its gaseous character, one of much larger bulk. It is a semi-solid or butyraceous substance. It can be handled, but it soon breaks up into running mercury and the gases. It is now obvious how the salts of ammonium may be readily made analogous to the salts of sodium and potassium. This body, NH, or one of nitrogen and four of hydrogen, is in reality a metal which unites with halogens and forms salts. 329 and one which ladies use very much in their scent-bottles, and as a diffusive stimulant. It is made by distilling with sulphate of ammonia and chalk. Chalk is carbonate of lime. The carbonic acid goes over to the ammonia and forms carbonate of ammonia. The way this is done in the arts is represented here. I have here a still, or a retort, not at all unlike the retorts which are used in gas making. Here the sulphate of ammonia, or the muriate of ammonia and carbonate of lime are placed, and they are heated together with fires placed under them, and the carbonate of ammonia being a volatile salt is sublimed and condenses in these chambers. It is afterwards distilled again. It sublimes at 1779, which is below the boiling temperature of water. The stills have got leaden caps, and the water heats the impure salt and sublimes the carbonate of ammonia which is afterwards taken out of the cap. This is also very largely manufactured. About 2000 tons are made annually of this salt. Various modifications of these plans are also used. For instance, the gaseous ammonia is led into a chamber of carbonic acid. The chamber has water at the bottom. The carbonate of ammonia is formed and crystallised, and afterwards sublimed. The aqua-ammonia of pharmacy, or ammonia water, or liquid ammonia, or hartshorn, is made by intro. ducing a base to keep back the acids, and the ammonia is distilled over. This ammonia is used for a great many purposes-as a diffusive stimulant in medicine. It is also used as an antacid in medicine; and largely employed to saturate carbonate of ammonia in ladies' scent-bottles, some aromatic substance being generally mixed with it. Now, look what a transformation is effected by the application of chemical agency: the refuse of camels, the offal of the streets, the fetid water of the gas-works, have become so transformed under the influence of chemistry that ladies preserve them in their scent-bottles as a cherished luxury. You see how these waste products may be used to furnish even luxurious utilities. But I must go faster with my subject. I now pass to coal-tar. Now, coal-tar is a very complex body. It contains a large number of substances, some of which are volatile, others more difficultly volatile, and others not at all volatile in the ordinary sense of the word. I have here a retort filled with tar, and I am now going to pass through that a current of steam; and you will see that after a little when it passes through freely it will distil over along with the water, and that this water will contain, swimming on its top, a certain quantity of naphtha. The steam which passes through the tar will take away the more volatile portions of the tar and condense it upon the top under the name of naphtha. What remains behind is a mixture of what is called dead oil and pitch. This dead oil is afterwards distilled off, and what remains behind in the retort is finally pitch. I must run quickly over the other salts of ammonia, and I will not enter into the details of the manufacture. For instance, this muriate of ammonia is not manufactured only in the way I have told you. It is manufactured in many other ways which it would tire you to describe. One of them is to take the gas water, and, instead of saturating it with strong acids like muriatic acid, to distil it with lime. The ammonia gas goes over, and is very readily condensed in water. It may be condensed in water or acids, and forms various salts. This process is much the best, as the badly smelling sulphuretted hydrogen is retained by the lime. There is another way of manufac turing this muriate of ammonia by acting upon sulphate of ammonia with common salt; but I will not tire you with all these details and modifications of the manufacture. You must ascribe it not to ignorance, but to the fact that I do not think it necessary to enter into them. I now pass to sulphate of ammonium, which is another salt very much manufactured from gas water. About 5000 tons of it are annually made in this country from gas water. It is made in the same way, by adding oil of vitriol to the ammonia of the gas liquid. It is used largely for manure. It is used largely for making alum; and it is employed also for making ammonia, or rather solutions of ammonia in water, by distilling it with lime, which keeps back the sulphuric acid. Carbonate of ammonia is another salt, | hydrocarbon. In distilling it in this way we obtain from 100 parts of coal-tar, of naphtha 9 parts, of dead oil 60 parts, and of pitch 31 parts, so that there are various substances obtained. I have only time, however, to deal with the naphtha. Now, naphtha itself, or the substance which we get over by distilling the tar with steam, is a general word also. I have placed on this diagram the products of the tar. Crude naphtha contains all these substances which are written down there; but I will refer you at present to the upper division. The crude naphtha contains, first, basic oils, or oils acting as bases; secondly, acid oils, or oils acting as acids; and thirdly, neutral hydrocarbons. You will notice in the diagram, as in all the diagrams which we shall use, that whenever we have a body acting as a base we colour it blue to show that it is a base, like this soda which coloured red water blue; when it is an acid we colour it red; and when it is neutral we colour it green; so that when you find a body written red it is an acid body; and when it is green it is a neutral This naphtha is now taken and purified and clarified. There is added to it sulphuric acid. The sulphuric acid takes up the basic oils which are at the top, and unites with them and forms salts-sulphates of these bases. (We will complete our distillation of the tar afterwards. It is making too much noise for me to have my lecture accompanied by it. We will finish it after the lecture, and you shall see the products in the next lecture.) The sulphuric acid unites with the basic oils and produces this "sludge," as it is termed by manufacturers-the bases united with the acid. toluol, xylole, cumol, cymol, and a great many other names with which I will not trouble you. They are compounds of hydrogen and carbon, and possess many degrees of volatility. For instance, benzol boils at 1770. This is one of the most useful of the substances. It is made from crude naphtha by a simple operation, taking advantage of its low temperature of ebullition. Here is a benzol still. The crude naphtha is placed in this still. It is a double still, into which steam is sent from this steam-boiler in order to heat the crude naphtha. The top of the still, you will observe, passes through a cistern of water. That cistern of water is kept at the boiling point of benzol, 177 degrees, and the vapour of the naphtha passes through the heated vessel, which is heated to 177 degrees. Benzol distils over at 177°; but toluo!, cumol, cymol, and the others boil at a much higher temperature. Therefore they are condensed at that temperature, and fall back into the still. The separation is, therefore, effected simply by means of keeping the benzol at its own boiling temperature, and cooling the others below theirs. It is a very volatile substance. It, no doubt, adds much to the illumination of our coal gas. We will show you this. I have here the means of showing you the gas, first, not passed through benzol, and then passed through benzol. I first take the gas not passed through benzol, and if I light it you see that there is little illumination. You can scarcely see it at all at a distance. Now, I will pass some gas through this benzol. It is now passing through, and you see how the gas has licked up this volatile body, and given us a stronger illumination. Benzol is, no doubt, one of the illuminating vapours which exist in common coal gas. Now these are extremely valuable, and it is from them that these coal-tar colours, which I am going to speak of presently, are obtained; but they are entirely lost by the manufacturer. They will probably be saved afterwards, but at present they are thrown away as a sort of tar. The first things that we obtain of any advantage are the acid oil and the naphtha. The naphtha itself-the crude naphtha of which there is a specimen there, is employed at once, without any purification, for the purpose of making india-rubber waterproof coats and similar articles. But it is purified for various very important purposes. When the most volatile portions are collected, what comes over are the acid oils. Now these acid oils consist of two acids-carbolic acid and cressylic acid. Carbolic acid has the formula C12HO; and the cressylic acid is what is called a homologue of the other, or contains C2H2 more. It consists of C1HO2. Common creosote is a mixture of these two acids. This carbolic acid which forms common creosote, is after purification, and when perfectly dry, a solid; and it is this beautiful acid which I have present here. I see the manufacturer of this very specimen in the room, and I wish he was lecturing here to tell you Now, this body, when acted upon by nitric acid, promore about it than I can. Before he sent me this beautiful duces what you will find in that big bottle-nitro-benzol. specimen I had never seen it in commerce solid; it is I must call your attention to nitro-benzol a little sciengenerally liquid. This carbolic acid when united with tifically. Benzol has the formula C12H6,-that is, it lime forms one of the most powerful disinfectants we have, contains twelve equivalents of carbon and six of hydrogen. which I will show you in my last lecture, when we come In nitro-benzol one of these equivalents of hydrogen goes to the subject of sanitary chemistry. When this acid is out, and one equivalent of oxide of nitrogen, NO, goes in treated with nitric acid it loses part of its hydrogen, and and substitutes it, and then forms nitro benzol, a subthat hydrogen becomes replaced by peroxide of nitrogen, stance which by itself possesses some peculiar characters. a lower oxide of nitrogen than nitric acid. When it is It smells strongly of bitter almonds, and it is employed treated with nitrogen three of these go away, and the now instead of bitter almonds, which is poisonous, for hydrogen is replaced by what is termed a compound making common almond soap. That common almond radicle-a body which plays the part of hydrogen, and soap which we buy is now perfumed with this nitrowhich forms this yellow substance called carbazotic acid. Carbazotic acid is carbolic acid, three of whose equiva-stitute for bitter almonds. It is much better for that It is also employed in confectionery as a sublents of hydrogen have been substituted by three equiva- purpose, because the bitter almonds contain prussic acid, lents of an oxide of nitrogen. may poison our friends. There is no chance of that taking and by the use of too large a quantity by our cooks we place when nitro-benzol is used. It is the basis from which we derive our tar colours, and the mode in which it is used for this purpose will require a little close attention to a chemical formula; but it is very interesting. Now, this carbazotic acid can be prepared in large quantity from creosote by the action of nitric acid, and it can be employed at once for dyeing. If I take a skein of silk and agitate it for a little in this carbazotic acid, it will take on the dye without any previous preparation, and it is dyed a beautiful yellow colour. You see how it has already taken on the colour, and in this way you can dye silks of a beautiful colour with this substance obtained from the former waste product of coal-tar. This material has also been lately employed, as almost everything is employed, for various other useful purposes. It is an excellent antiperiodic, like quinine, only when employed it dyes the skin of the patients yellow, and they, therefore, have a sort of artificial jaundice. But it has also been suggested for another purpose. It may be mixed with arsenic and other poisons for the purpose of rendering them more ready of detection. It imparts to the arsenic a bitter taste, and it also turns the person to whom it is administered yellow, and in a case of slow poisoning this yellow appearance would be an indication that there was something wrong. Cressylic acid, another of the compounds of crude coal oil, is not much employed in the separate state. I now pass to the neutral hydrocarbons. The neutral hydrocarbons are also various. They are called benzol, benzol. If nitro-benzol is acted upon by water and by iron, of which I have put down the symbols here-nitro-benzol + water + iron = C12H5 (NO) +2 HO+4 Fe-the iron takes away all the oxygen from the water, and the oxygen from the oxide of nitrogen. There are six equivalents of oxygen, which the iron takes to itself and forms iron rust with it. This rust remains, and the two of hydrogen of the water now joins itself to the C12HN, and produces this body here, CH,N, aniline. That is to say, the iron takes away the oxygen and leaves oxide of iron and aniline as the result. Now, this aniline is a most important body. It was first investigated by Dr. Hofmann, who has made with regard to it a series of the most brilliant researches, out of which have arisen these coal-tar colours with which we are now acquainted. Aniline is an ammonia. It is a body exactly resembling the base ammonia, but it is what is termed a compound ammonia. Here is the constitution of ammonia : CHEMICAL NEWS, June 14, 1862. H NH H Royal Institution of Great Britain. I have replaced one atom of hydrogen with a compound radicle which chemists call phenyle, and I obtain what is termed aniline. This aniline is therefore a compound ammonia in which the radicle phenyle replaces one of hydrogen. When Hofmann began his researches upon this subject, aniline was made by a laborious process by distilling indigo with potash; and the possession of a pound of aniline in any chemical laboratory would have been looked upon as a wonder. Now you see that out of coal-tar we can present to you upon the lecture table whole gallons of aniline, and it is now sold for a few shillings a pound. I have here a series of the substances formed in the production of Magenta. I am indebted for them to the discoverer of 10saniline. Here is a block of coal weighing 100 lbs. This block of coal produces this amount of tar when distilled. Here is the amount of aniline which, with the most economical manufacture, can be extracted from that block of coal; but still, although it appears to you only a small quantity, it is, in fact, a most economical quantity compared with the processes which were formerly employed. It is out of this aniline that the peculiar dyes are obtained, and this is the quantity of the Magenta dye which can be obtained from that large quantity of coal. If you will examine these products after the lecture, you will find this a very instructive proportional series. Now, it is out of this aniline that we produce mauve, Magenta, roseine, azulire, bleu de Paris, and the various colours which have received arbitrary names. It was known for a long time that the products of distillation of coal had a strong tinctorial power. Here, for instance, I have one of them-a body called pyrrole. I have here a piece of pine-wood, which I see Mr. McIvor has made, for a theatrical purpose, in the shape of a dagger. I will now moisten this with muriatic acid, and then place in a deep vessel which contains a few drops of pyrrole. You see that it suddenly gets as it were covered with blood. This muriatic acid is mixing with it, and the dagger comes out in a sanguineous state. You observe the strong tinctorial power which this substance has by the deep colour which it produces. Now this tinctorial power has been known, in fact, for a long time, but the mode of manufacturing the substance readily and economically was not known. Here I have a small quantity of aniline, and I agitate it with water; and now, if I add to that a solution of bleaching powder, you will see the effect it produces. It was long known that this aniline gave a purple colour with bleaching powder. The colour comes after a little while; it does not come immediately, but you see, as I add it, that the aniline produces a mauve or a purple colour; and this was known for many years, before persons knew now to make it for commercial purposes. This is now a colour used in the arts. The first person who introduced this, and to whom the greatest credit is due for its production, was Mr. Perkin, a pupil of Dr. Hof. Mr. Perkin had seen and admired the tinctorial power of aniline, and he had an ambition to render this fugitive colour permanent, and to introduce it into the arts as a dye, and he succeeded admirably. The mode is this: this aniline is a base, and unites with sulphuric acid as ammonia does, and it forms sulphate of aniline. He mann. 331 takes equivalent quantities of aniline and bichromate of potash, and mixes them together, and in a little while, after standing together, they form this very unpromisinglooking black powder. You see this black powder here; it looks extremely unlike a dye. Now, when this colour is washed with coal naphtha, this nasty-looking_brown resinous substance is dissolved out of it by the coal naphtha, and then there remains a still unpromising substance, but which is rather purple in colour. When you treat with alcohol this brown powder, which has been washed with naphtha and had the resin taken out of it, it forms with the spirit a strong solution of mauve. This beautiful purple colour is obtained in this way,-by dissolving out of the brown powder the purple colour by means of alcohol; and it is this purple colour which is used largely in dyeing. It is readily soluble in alcohol. If I take a washing-bottle of alcohol, and throw a little of it upon the substance, you see that the beautiful purple colour of this substance is readily manifested. [The substance had been previously spread on a white paper screen, and there remained unapparent; but upon the projection of the stream of alcohol upon the screen the purple colour was produced where the alcohol came in contact.] It is a substance which you can easily detect and find out whether you are dealing with this colour, or dealing with some colours derived from lichens, which have a similar character. I have here aniline purple, and I now add to it a little sulphuric acid, and I will show you that it is very easy to detect which colour you are dealing with. The sulphuric acid turns it first to a dirty green. If now I add to this a little water, this dirty green becomes a beautiful blue. The light has become bad. The day is not a good one for showing you these colours. I am afraid this day-light, or want of day-light, will render it necessary for you to take what I say on trust. The addition of water makes it a beautiful blue. This is a second test for it; but if now I add a little more water to it, it is restored again to its purple state. You see on pouring it into this large jar that it resumes its beautiful purple, and in this way you can easily detect its presence. The sulphuric acid turns it a green, a little water turns it a deep blue, and a large quantity of water brings it back to its original purple condition. It is easy to dye with this aniline purple; in fact, ladies can dye with it perfectly themselves. It is only necessary to use for this purpose hot water-water so hot that you cannot bear it with your hand, but not boiling. The best temperature is about 150°. If you take this hot water and add to it a little tartaric acid and a little of this aniline purple, and then place the silk or woollen in it, it becomes dyed. It is easy to attach the colour to animal fibre, but not to cotton. In the next lecture I have to explain to you its application with regard to cotton. I have here the colouring matter, and now I will add to it a solution of tartaric acid, which is necessary to produce the colour. After that all I require is to place my silk in this solution, and to rinse it for a little time in it, and you see that it quickly takes up the colour and produces that beautiful mauve which is now so familiarly known. It is, therefore, a substance which is extremely easily applied,—almost as easily as the carbazotic acid. Although I am within a minute of the hour, I must ask your attention for five minutes more. The next dye to which I have to direct your attention is Magenta; or, as it is more properly called by Dr. Hofmann when it is in the state of purity, rosaniline. I should like also to prepare this before you, and show you the method. Any weak oxidising agent less strong than bichromate of potash, produces this substance. I will take here bichloride of tin for my purpose. I add to this anhydrous bichloride of tin an excess of aniline. It must be done cautiously, for the action is energetic. As soon as the action subsides we will add a little more, and finally heat it until I drive off all the aniline. I must have an excess of aniline and then drive it off, after which the Magenta will be seen to appear. This will take a little time to perform. Mr. McIvor will now heat this gently, passing it slowly over the flame at first as the action is violent, and will continue the heat until our Magenta begins to appear. After a little time we shall have a very good imitation of Magenta, but not nearly so good as is produced by the manufacturers, who now produce it on the most magnificent scale; I allude to Messrs. Simpson, Maule, and Nicholson, to whom I am indebted for a number of the illustrations that are exhibited here, and for this crown, which is made of the substance in the ordinary condition in which it is sold-acetate of rosaniline. You see what a magnificent crown it is. The formula of rosaniline I have written here. think I may easily predict that, in a few years, England will be a colour-exporting instead of an importing country. In this country, even now, coal-tar, notwithstanding all these applications of it, is worth only from penny to three halfpence a gallon. These discoveries will probably alter the whole character of calico printing, and make this country an export market of colours. As this is a highly important industry, I have solicited your attention to two other lectures on it. CHEMICAL SOCIETY. Dr. A. W. HOFMANN,. F.R.S., President, in the Chair. It is what is called a triamine, or it is three atoms of PROFESSOR WURTZ delivered a lecture "On Oxide of a Link between Mineral and ammonia which have coalesced into one; and this rosani- Ethylene considered as line forms, with acetic acid and other acids, deeply-mixture of clefiant gas and chlorine gave rise to the proOrganic Chemistry." It had long been known that a coloured salts, of which this ordinary Magenta is one. You will see crown in the Exhibition which I think is one of the most remarkable of the scientific exhibits which we possess. The crown is composed of the acetate of rosaniline. You see the difference between this rosaniline and mauve. It is of a much redder colour than mauve, and is more definite in its character. Mauve is a neutral body, not possessing either basic or acid properties; while, on the other hand, rosaniline is a true ammonia-a true base. Now we have formed our Magenta by this experiment. I think I can show you the colour better if I pour it into water and add an acid. You will then also see its tinctorial power. After a little time it will dissolve and form a solution of this substance. It is a powerful tinctorial body. There [referring to a bale on the lecture table] is the quan tity of woollen which is dyed from the amount of Magenta produced from 100lbs. of coal. There is the 100lbs. of coal which produces this small quantity of Magenta, and that bulk of wool is dyed from it, so that you see its tinctorial power is great. As I have only given you an introduction to the subject, and you will afterwards have the application of this to calico printing, I will only say one word as to the blue colour which is obtained, and in the next lecture, and the lecture afterwards, we shall have an abundant opportunity of following up this subject. Not only have reds and purples been obtained in this way, but a yellow has recently been procured by Mr. Nicholson, to whom we are so much indebted; so that yellow, red, and blue, the three primitive colours, are now to be obtained from the coal-tar. Here is one called bleu de Paris, or bleu de Lyons, or azuline. It is obtained sometimes from aniline by the action of qxidising agents, such as bichloride of tin, at a high temperature under pressure-a temperature of 350°. But most of these blue colours are made from carbolic acid, and not from aniline. I think I can show you here the blue colour. I have put some of this blue upon this paper. There is one which is obtained from carbolic acid or from creosote. The process, however, is not known; it is still Kept a secret in the arts, but you see what a beautiful colour it is; and what a power we have in possessing the three primitive, colours, by the mixture of which we can obtain so others. many As a new art, the manufacture of these colours is of great importance. Hitherto, England has been dependent upon foreign countries for its dyes. We have imported madder from Holland, from Turkey, and from France, and blue colours from India, in order to produce our calico prints; but you see now that we are likely to reverse this. We find in this waste product, coal. tar, the three primitive colours out of the mixture of which we can produce almost any shade we desire; and without taking upon myself the character of a prophet, I duction of an oil commonly called Dutch liquid. Various Ag2O2 =2AgBr+(C,H,)” C2H2OO2 the acetic acid was removed, and glycol, the hydrated sition or (C2H1)"O,HCl, was formed, which was decomposed by caustic potash and the oxide of ethylene set free. The action of oxidising agents on this substance gave rise to two series of compounds, the first of which contained three bodies, represented by the following formula:-C2HO; CH12; CO. These were analogous to the series produced by the oxidation of hydrochloric acid, namely, HCIO; HC102; IICIO,; HCIO. The other series were as follows:CH2O2; CH2O; C.IO; which were comparable with the successive products of oxidation of phosphoretted hydrogen, namely, PHO; PHO; PHO3. 3 The oxide of ethylene seemed in many of its reactions to bear a remarkable analogy to an oxide of a metal; it was capable of forming definite compounds with acids, and would even displace some mineral bases from their combinations with acids, its salts also formed double compounds with salts of barium, calcium, iron, Zinc, copper, lead and mercury, and in these double salts there were always two equivalents of the metal; from various considerations, however, it would appear that the equivalents of these metals should be doubled; an argument in favour of this supposition might be drawn from their specific heat, Equivalent of carbon = 12. CHEMICAL NEWS, June 14, 1862. Manchester Literary and Philosophical Society. which was half that of many of the other elements. If the equivalents were doubled, these metals would occupy a position in the salts precisely similar to that of oxide of ethylene. Oxide of ethylene was capable of combining directly with water by the assistance of heat in the same manner as some metallic oxides; if the water were in excess glycol was formed, but inferior hydrates containing two, three, or four equivalents of the oxide to one of water could be prepared; these were analogous to certain hydrates of stannic and silicic acids; the oxide also combined directly with hydrochloric acid, forming a basic salt. In addition to this great variety of saline compounds, oxide of ethylene was capable of combining with ammonia, forming compounds containing one, two, or three equivalents of oxide to one of ammonia; of these there were several analogues in the ammonio compounds of copper, mercury, and other metals. On the whole it would appear that the oxide of ethylene in the compounds it was capable of forming with acids, &c., bore a great resemblance to the mineral oxides, and might serve as a link to connect together the two branches of chemistry by showing the analogies that existed between them. MANCHESTER LITERARY AND PHILOSOPHICAL SOCIETY. J. P. JOULE, LL.D., F.R.S., President, in the Chair. MR. ANDREW KNOWLES was elected an Ordinary Member of the Society. A Paper was read "On Non-Modular Groups," by the Rev. T. P. Kirkman, A.M., F.R.S., and Hon. Mem. of the Literary and Philosophical Societies of Manchester and Liverpool. The following Report of the Council was then read by one of the Secretaries : In presenting the Annual Report, the Council congratulate the members on the improved condition of the Society, especially as regards its financial position. The balance in the Treasurer's hands, as seen in his Report annexed, was on March 31, 1861, 587. 2s.; whilst on March 31 last it amounted to 2481. 68. 7d.; and this in spite of necessarily heavy expenditure incurred in the printing of the " Proceedings and of the Volume I., 3rd series, of " Memoirs," which is now ready for distribution. This improvement is mainly owing to the fact that the members have almost unanimously supported the Council in their proposal to raise the subscription to 27. 29. per annum, as the only available means of enabling the Society successfully to carry out its objects. The number of ordinary members on the books last year was 207; it is Since the last Annual Meeting seven members have resigned, eight new members have been elected, and four ordinary members have died, viz.: Professor Eaton Hodgkinson, F.R.S.; Dr. M. Satterthwaite; Mr. Absalom Watkin; and Mr. George Woodhead. now 204. Professor Hodgkinson's high scientific eminence as an experimentalist and as the founder of the principles of many branches of mechanical science, is now universally acknowledged; and the members will be proud to recollect that our illustrious townsman was for forty-one years connected with the Society, and that it was through the medium of our "Memoirs" that the greater part of Hodgkinson's important researches were made known. The following is the list of Papers published by Professor Hodgkinson in the Society's "Memoirs": 1. Vol. iv., second series, p. 225.-" On the Transverse Strain and Strength of Materials," read March 22, 1822. 2. Vol. v., second series, p. 354.-" On the Forms of the Catenary in Suspension Bridges," read February 8, 1828. 3. Vol. v., second series, p. 384.-" On the Chain Bridge at Broughton," read February 8, 1828. 333 4. Vol. v., second series, p. 398.-" A few Remarks on the Menai Bridge," read December 12, 1828. 5. Vol. v., second series, p. 407.-" On the Strength and best Forms of Iron Beams," read April 2, 1830. 6. Vol. vii., second series." On the Measure of Moving Force," read April 30, 1844. The Council congratulate the members on the possession of the life-like bust of the late Professor Hodgkinson, which, thanks to the liberality of a few gentlemen, now adorns our rooms; and they also notice that Mr. Robert Rawson is engaged in preparing a valuable memoir of our deeply lamented friend, the first half of which has already been read before the Society. Of the Honorary and Corresponding Members, the Council have to notice the deaths of the celebrated French philosopher, M. Biot, and Dr. Peter Barlow, F.R.S. Notwithstanding the natural claims which the late very successful meeting of the British Association for the Advancement of Science, in Manchester, made upon the scientific resources of our town, it is gratifying to observeno falling off either in the quality or quantity of the original communications presented to the Society during the past Session. The following is the list of Papers and Communications laid before the Society in the Session 1861-62 :— October 1, 1861.-"Observations of Comet I., 1861," by J. Baxendell, F.R.A.S. October 15, 1861.-"On the Irregular Barometric Oscillations at Geneva and on the Great St. Bernard, and their relations to the Mean Temperature and the Fall of Rain," by G. V. Vernon, F.R.A.S. October 29, 1861.-" On the Putrefaction of Blood," No. 1, by Dr. R. Angus Smith, F.R.S. November 26, 1861.-" Additional Observations on the Permian Beds of South Lancashire," by E. W. Binney, F.R.S., &c. "On certain Scales of some Diurnal Lepidoptera," by Mr. John Watson. December 10, 1861.-" Nouveau Système de Communi cation Télégraphique, rendant impossible toute collision de trains sur les chemins de fer," by Professor Baulet, of Persignan, communicated by W. Fairbairn, LL.D., &c. December 24, 1861.-"On the Influence of the Seasons on the Rate of Decrease of the Temperature of the Atmosphere, with the Increase of Height in Different Latitudes of Europe and Asia," by J. Baxendell, F.R.A.S. January 7, 1862.-"Experiments on some Amalgams," by the President, J. P. Joule, LL.D., &c. "On the Conductibility of Heat by Amalgams," by Dr. F. Crace Calvert and Mr. Richard Johnson. January 21, 1862.-On the Action of Nitrate of Sodium on Sulphide of Sodium at different temperatures," by Dr. Ph. Pauli, communicated by Professor Roscoe. "On the Convective Equilibrium of Temperature in the Atmosphere," by Professor William Thomson, LL.D., &c. February 4, 1862.-"On the Theory of the Trans. cendental Solution of Algebraic Equations," No. 1, by the Rev. Robert Harley, F.R.A.S. "On the Causes of Sickness and Mortality in the Manufacturing Towns of the North-West of England," by Dr. C. J. Shearman, communicated by Dr. R. Angus Smith. February 18, 1862, Note on a Differential Equation," by A. Cayley, F.R.S. "On the Present State of Meteorology," by T. Hopkins, M.B.M.S. March 4, 1862.-On the Direction of the Wind at Manchester during the years 1849-61, at 8h. a.m." by G. V. Vernon, F.R.A.S. "On the Theory of the Transcendental Solution of Algebraic Equations," No. 2, by the Rev. Robert Harley, F.R.A.S. "Memoir of the late Professor Eaton Hodgkinson. F.R.S., &c., Part 1st," by Robert Rawson, Honorary Member of the Society. Observations on Atmospheric Electricity," by Professor Wm. Thomson, LL.D., &c. March 18, 1862." On the Probable Cause of Electrical |