increased from 100 to 253, and the colour deepened fourfold.

Mr. Fryer has also published some very interesting facts on the influence of heat on the cane sugar, and I here take the liberty of extracting from a paper of his the fol

heat; the continuance of any syrup for two hours at any given temperature would cause just double the mischief which would be produced by its continuance at the same temperature for an hour. But as regards the heat, the mischief increases about as the square of the difference from 140° the highest innocuous temperature. So at 160° during any given time a certain degree of mischief would be done. To keep the same syrup for the same time at the heat of 180°, would give four times the mischief; at 200°, nine times; the difference of 180° from 140° being twice as great as that of 160°, and that of 200° being three times as great."

I should have wished to have dwelt at some length on the interesting application which has been made of late years, especially on the Continent, of another coal product, which, like most of those whose origin is due to coal, has received many valuable and beautiful applications. The one I now refer to is called bisulphide of car-lowing facts :bon, and is applied with great success not only to the "We now come to the boiling. All heat above 140° extraction of fatty matters from various seeds and fruits, is capable of exerting an injurious effect. As regards the such as olive, linseed, &c., but in Algiers for extract-time this effect is proportionate to the duration of the ing from flowers various essential oils, commonly called perfumes, such as essence of roses, lavender, jasmine, &c. You will, no doubt, remember also the useful application which bisulphide of carbon receives in the hands of Messrs. r Allbright and Co., of Birmingham, in separating the common phosphorus from the red or amorphous phosphorus L now applied to the manufacture of chemical matches, as explained to you in my first lecture of last year's course. I cannot conclude what I have to say respecting coal products, without stating the fact that, since I had the honour of delivering a lecture in this room, in 1862, many beautiful and valuable discoveries have been made in connection with coal-tar colours. Dr. A. W. Hoffman has succeeded in obtaining some magnificent purples, by a process as curious as it is highly scientific, and such as might be expected from so talented a chemist. Since then a splendid green colour, called verdine, and which has the curious property of retaining that colour in artificial light, yea more than that of increasing in beauty in the presence of that light-has been discovered by M. Eusebe. A beautiful fast black, easily applicable to the art of calico-printing, has also been devised; and lastly, in the hands of Messrs. Simpson, Maule, and Nicholson, the well-known colour called magenta, and a beautiful blue called opal, have not only been much increased in beauty, but their cost of production has been materially reduced. In fact, at the present day, every shade of colour is produced from coal tar products; but the subject is too vast for me to attempt now to enter into details as to their mode of production and application.

This mischief consists partly in the change of colour, partly in the change of a quantity of cane sugar or sucrose into fructose. Both these kinds of sugar are present in all neutral saccharine solutions. Sucrose is the ordinary crystallised cane sugar; fructose exists more especially in some kinds of fruit, such as grapes, gooseberries, cherries, oranges, &c., which refuse to form well-defined crystals. Further, I should remark that, under the influence of heat, as just stated, cane sugar or sucrose, is converted into grape sugar or fructose, and that the presence of fructose interferes in a most extraordinary manner by preventing the free crystallisation of sucrose. Thus, for example, every particle of fructose in a mixed solution detains from crystallisation its own weight of pure sugar. In fact, it would be impossible, after mixing equal weights of loaf sugar and fructose in a solution to recover the former in a crystalline state. The change produced by the atmosphere alone, without the action of heat, shows the necessity of proceeding instantly to raise the temperature to the boiling point, and the concentration should be continued without loss of time. The temperature should not, however, be raised beyond the lowest effectual heat.

As the hour is advancing, I must, though with regret, leave the interesting subjects which have reference to coal and its products, and pass to another class of manufacture. The first of these has reference to the refining of sugar, and among the several improvements which have been effected in this branch of manufacture during the last few I will now call your attention to Mr. Fryer's "conyears none is more important in its general bearing than cretor," as he terms the apparatus, which is delineated that recently brought to the notice of the public by Mr. on page 718. It consists of A A, inclined corrugated Alfred Fryer, of the well-known firm of Fryer, Benson, plates, over which the juice flows; al a1, connecting and Foster, of Manchester. This gentleman has published gutters for joining plates; B, furnace; CC, flue under some valuable information on the composition of the plates; DD, tube-box heated by waste heat of furnace; sugar-cane juice, and the alterations it undergoes under d1 d1, supply cistern for revolving cylinder; E E, revolving the influence of heat and atmospheric air, and has con- cylinder, through which the juice is passed after leaving ferred on the colonies a great boon by inventing an the plates AA; el el, curved blades revolving with apparatus which will effect a great saving in obtaining cylinder, and exposing the liquor to the hot air; e2 e2, sugars. Mr. Fryer's experiments on the cane juice teach friction rollers for supporting cylinder; F F, fan for us that, instead of only extracting 49 per cent. of drawing a current of air through tube-box DD and the juice, as is usually the case, when the canes are cylinder A A; HH, engine for driving fan and cylinder; worked by the old system, 61 per cent. can be ob-h1 h1, shaft for giving motion to cylinder E by means of tained with a good steam engine having 24 inch rollers; and by pressing the megass a second time through the rollers as much as 70 per cent. can be obtained; and Mr. Fryer does not doubt that even 80 per cent. may be reached, if more attention is paid to the pressing of the canes through the rollers. Mr. Fryer has also published some interesting facts on the action of the oxygen of the atmosphere on cane juice. Thus he has observed that the juice rapidly darkens, and that this increase of colouration is not only an indication that the juice is undergoing deterioration, but that no amount of defecation will subsequently remove this colouration. He has further noticed that cane juice rapidly becomes acid, and the acidity increases also in a very rapid manner. He gives an instance-a pattern of too many others-where the juice, after expression flowed down a spout 250 feet in length, from the mill to the boiling-house, occupying in its descent about half-a-minute. The amount of acidity

pinion h2; II, covers for retaining around cylinder E the the steam given off from plates A A.

From the further end of the cylinder a pasty mass is discharged, and, in cooling, it hardens into a non-crystalline homogeneous substance likely to be long known as Fryer's concrete." its material is simply cane juice deprived of its vegetable albumen and water, and, not being contaminated by molasses or caramel, is admirably fitted for the operations of the refiner, and will, therefore, command his attention. Allow me, further, to add that his process is easy to conduct; the apparatus, as you see, is simple and self-acting, not liable to derangement; that it performs a large amount of work; and therefore proves a material saving to the sugar producer. I cannot conclude my remarks on Mr. Fryer's invention, as applicable to the colonies, better than by repeating here the words exFressed by the Governor of Antigua, who said, "I believe firmly that you have opened a new era of prosperity to

This illustration is one of the first applications of a new process for producing surface blocks from a drawing. It has been produced for this Society as an experiment. The drawing was placed in the hands of the artist on Wednesday morning, and the metal blocks ready for the printer were delivered the following day. It is right to state that, the drawing being of a geometric character in outline, the dificulty of production is greatly increased. It should be added, that the drawing having been placed in the hands of a wood engraver of eminence on Tuesday morning last, it was returned by him as impossible to execute wood blocks in time for this week's Journal. The process and its bearing on Art production will form the subject of a Paper to be read at an early meeting of the Society.-ED. S. of A. J.

D

our colonies, and heartily wish you abundant success in the course on which you have entered." As to the advantages which a sugar refiner in this country will derive from employing Mr. Fryer's "concrete," instead of having to refine the molasses and coarse sugars usually imported into this country, they are so obvious that it would be really a loss of time to enlarge upon them. The saving to the refiner in having nearly pure sugar to operate upon, and not having to contend with the removal of colour, converted sugar, caramel, and other impurities, will at once convince you of the support and approbation the article will receive from the sugar refiner.

apparatus, where they are subjected to a comparatively intense cold, and yield large quantities of a double chloride of magnesium and potassium, which, on being subjected to heat in a furnace, gives hydro-chloric acid, magnesia, and chloride of potassium. This application of Carré's apparatus, in this instance, shows the simplicity and practicability of it. It is based on rather a different principle to those of Kirk and Harrison. To obtain a low temperature he applies heat to a vessel which contains a saturated solution of ammoniacal gas. This drives off the gas, which is made to pass into a vessel surrounded with cold water, where it liquifies itself by its own pressure. If then the heat be removed from under the solution, its temperature will gradually fall, and it will become again susceptible of re-absorbing the ammoniacal gas, thus facilitating its evaporation from the vessel in which it has condensed, and as it is necessary for the passage of the liquified ammoniacal gas into its gaseous form that it should absorb the heat from the surrounding medium, let it be water or any other fluids, their temperature will gradually decrease. The following diagrams will enable you to understand better the working of this invention :

FIG. I

If, at the commencement of this lecture, I drew your attention to the value of intense heat produced at a small cost so as to enable our manufacturers to carry on their various processes, it now becomes my duty to inform you that of late years the cheap production and application of low temperatures has become a necessity, especially since organic products have been manufactured on an extensive scale. Three different machines for obtaining these low temperatures have been brought to public notice, viz.: First. That of Mr. Kirk, who has applied in a beautiful manner some of the physical laws discovered by Dr. J. P. Joule and Professor W. Thomson, in their researches on the mechanical theory of heat. Thus, Mr. Kirk succeeds in producing a low temperature by condensing under high pressure atmospheric air, which, on being allowed to resume its primitive volume, produces cold, for the compressed air cannot resume its primitive volume without the essential element for its expansion, namely, heat; and if the apparatus is properly contrived, which is the case in that of Mr. Kirk's, the heat necessary for the expansion of the compressed air is supplied to it by the body whose temperature is to be lowered. Although the construction of this machine is exceedingly costly, still it has been employed at Mr. James Young's works at Bathgate with great success to the cooling of paraffin oil to extract from it the solid paraffin which it contains. 1. Before each operation incline the apparatus horizonThe second apparatus is that of Messrs. Harrison and Co., tally, and maintain it about ten minutes in the position of London, who employ ether as the medium for pro-represented in Fig. 1. 2. Place the boiler (A) in the ducing low temperatures. The third is that of M. Carré furnace, and the refrigerator (B) in a bucket filled with -in my opinion the cheapest and most practicable appa- cold water, so that the summit of the refrigerator be ratus yet invented for the purpose, the more so that it is applicable for household as well as for manufacturing purposes. Although I, like many of you, have witnessed the production of ice by it at the late exhibition, still I was not prepared to learn that it could be applied with economy to the extraction of some of the salts existing in sea-water. Still such is the fact. M. Ballard, a well-known French chemist, after many years' study and labour, succeeded in extracting from sea-water two products, which play a most important part in most of our large chemical works, viz., sulphate of soda and chloride of potassium. To produce the first, under ordinary circumstances, extensive works are required, such as are found at St. Helen's, and Newcastle-upon-Tyne, where thousands of tons of common salt are acted on by vitriol, which gives rise to muriatic acid and sulphate of soda. As to the salts of potash, the French, as well as ourselves, are dependent for it upon the forests of Russia and the native forest of Canada. By M. Ballard's discovery, France will free itself from a dependence upon foreign supplies for the potashes she may require, as well as the sulphur, and will also do away with the public nuisance, namely, the conversion of common salt into sulphate of soda. Without entering here into details, let me state that M. Ballard operates as follows:-In the early part of the spring season, considerable quantities of sea water from the Mediteranean are run into large shallow reservoirs. In the summer season the water evaporates, a certain proportion of common salt, separates, and the concentrated water is stored in other reservoirs until winter, when it is again allowed to flow back into the shallow reservoirs, where it yields, during a cold night, thousands of tons of sulphate of soda. The mother liquors from which the sulphate of soda has separated are allowed to flow into Carré's

FIG. 2

B

covered with two or three inches of water. A small quantity of oil is poured into the tube which is placed in the upper part of the boiler, in which also a thermometer is placed. The apparatus is heated moderately until it reaches 266°. The apparatus is then removed from the fire, and the boiler is placed in the bucket of cold water. The hole of the refrigerator being stopped with a cork, and the tin vessel surrounded with alcohol, having previously nearly filled it with water, the congelation takes place by the evaporation of the liquid aminonia in the condenser.

FIG.3

B

surfaces, which in their turn will heat the atmosphere of the compartment. We shall, I am happy to say, within a year or two, know if M. Pelon's invention will be capable of general adaptation, as it is now being practically tested on one or two of the French railways.

Proceedings of Institutions.

KENT ASSOCIATION OF INSTITUTES.-The first annual meeting of the council was held at Ashford, on the 6th of July last, when H. Whitfeld, Esq., of Ashford, presided. It appears from the report that, immediately after the formation of the society, in July, 1864, the committee forwarded to every known Institute in the county, a prospectus, setting forth the objects and rules of the Association. They also issued a series of questions, with a view to the preparation of a table descriptive of the nature, position, and operations of Kentish Institutes. The replies placed the committee in possession of the following useful information:-That the Institutes in Kent number about seventy: of these twenty-five are termed Literary, or Literary and Scientific; ten, Mechanics' Institutes; seven, Mutual Improvement Societies; two, Soldiers' Institutes; six, Working Men's Clubs; ten, Young Men's Societies: six, Reading Societies; and four bear the less definite name of Institute. Most of these societies possess libraries, which contain in the aggregate about thirty-two thousand volumes, and are circulated amongst nine thousand members. Lectures are annually delivered at about fifty of the Institutes. Penny readings appear to have been successful at upwards of twenty. In-door amusements, such as chess and draughts, are provided by twenty; and out-door sports, as cricket, by seven. About thirty-five of the Institutes possess reading-rooms. In twelve classes have been formed for instruction in one or more of the following subjects:- Reading, arithmetic, writing, French, drawing, Latin, and music. Only six appear to have given attention to the schemes of examinations connected with the Society of Arts and other Educational Societies. The apparent wants of many of the Institutes may be classified thus:-1. Means of obtaining, at small cost, the services of suitable lecturers. 2. An acquaintance, on the part of the members, with the advantages derivable from the Society of Arts and other examinations. 3. Teachers qualified to conduct evening classes. 4. The formation or extension of libraries. 5. The pos session of commodious premises. 6. That measure of public support which should be received specially from those classes for whose benefit the Institutes exists. To aid in supplying these wants (says the report) is the chief duty of this Association, and the committee have to point out how far they have been able to promote so important an object. A list of gentlemen willing to give lectures or readings to Institutes (on payment of travelling expenses) has been prepared and published. It contains at present only twelve names, but it will, in all probability, be considerably extended before the next winter season. The Society of Arts Elementary Examinations, also the Oxford Local Examinations, have been brought prominently before the notice of the inhabitants of Kent; and the Committee rejoice that their efforts in this direction have been crowned with no small measure of success. Through the liberality of gentlemen taking a great interest in the work of adult education, the

Although the evening is far spent, I cannot leave you withont calling your attention to a very ingenious mode, devised by M. Pelon, for warming railway carriages during cold weather. You are too well acquained with the present clumsy and expensive method now in use to require any description from me. The only remark I shall make upon it is that it is the boon of those who are in least need of it, namely, firet-class passengers, whilst those of the second and third classes have not that luxury supplied to them. To avoid loss of time, I shall not attempt to describe the various methods which have been proposed as substitutes for the one at present in use, but shall at once state that M. Pelon's method is based on the conversion of force into heat, the heat in this case being generated by friction; and from what I stated in my first lecture you must be perfectly au courant of what is understood in the present day of the conversion of heat into force, and vice versa. All those persons who were fortunate enough to visit the French Exhibition in 1855 must have been struck with a machine, invented by Messrs. Mayer and Beaumont, which generated enough heat to convert water into steam and thus obtain a motive power; and this was effected without fuel or electricity, but by mere frictional heat, which they obtained by causing a wooden mandril surrounded with tow to revolve with great rapidity inside a copper cylinder which itself was surrounded with a small quantity of water. The great merit of the invention of these gentlemen, and which drew upon them the special attention of the Emperor, was that neither the towed mandril, nor the copper cylinder were materially injured or deteriorated after many days' working. This important end was attained by them by allowing a gentle flow of oil to run constantly through the cylinder, thus preventing immediate contact between the towed mandril and the copper cylinder. In fact, the frictional heat was produced through the friction which took place between the particles of oil themselves, preventing thereby all wear and tear. Notwithstanding the ingenuity displayed in this invention, still as a means of obtaining motive power it was useless, for more force was required to generate an amount of heat than could be yielded by the friction of the particles of oil. But in the application which M. Pelon has made of this invention to the heating of railway carriages, the motive power required to generate the heat being produced with-committee are in a position to offer prizes, in books, to out cost to railway companies, as it is caused by the very act of the travelling of the carriages themselves, the cause which accounted for the failure of the principle as a practical mechanical application, namely, the production of the force required to work it, is overcome. M. Pelon pro poses to fix one of Messrs. Mayer and Beaumont's mandrils under each railway carriage compartment, and to convey the heat produced by the revolution of the towed mandril to the compartment itself by means of metallic conducting

successful candidates at the examinations. Arrangements have been made for the establishment of a circulating library. For an annual subscription of two guineas, schools and Institutes will be entitled to fifty volumes at one time, which may be exchanged at the expiration of three months. Numerous applications have been made to the secretary for information as to the most suitable description of building for Institute purposes, and also as to the usual modes of raising funds for the erection of