Abbildungen der Seite

ed by himself, and described in the became white hot; the potassiuin rose Bakerian Lecture for 1806, which like. in vapour; and, by increasing the dise wise seem to shew that the nitrous acid tance of the cup froin the wire, the which appears in many processes of the electricity passed through the vapour of Voltaic electrization of water, cannot the potassium, producing a most brilliant be formed unless nitrogen be present. fiame, of froin balf an inch to an inch

In answer to the objection that both and a quarter in length, and the vapour acids and alkalies may be produced froin seemed to combine with the platina, pure water, other very demonstrative which was thrown off in small globules, experiments were made, viz. one series in a state of fusion, producing an appear. in a jar filled with oxygen gas, and ano- ance similar to that produced by the ther in an apparatus, in which glass, combustion of iron in oxygen gas. In water, mercury, and wires of platina, all trials of this kind hydrogen was prowere present. In the first, the result duced, and in some of them there was a was, that in no jostance in which slowly loss of nitrogen. This seemed to lead distilled water was employed, and in to the inference that nitrogen is decorwhich the receiver was filled with pure posed, but in other experiments it was oxyges from oxymuriate of potash, certain there was no sensible quantity of was any acid or alkali exhibited; even nitrogen lost. The largest proportion of when nitrogen was present, the indica- nitrogen which disappeared in any extions of the production of acid and periment was the of the quantity alkaline matter were very feeble. In used, and though it cannot be positively the second series of experiments, the inferred that it was not decomposed, yet oxygen and hydrogen produced froin Mr. Davy thinks it more likely that water, were collected under morcury, the loss is owing to its combination with and the two portions of water com- pascent bydrogen; and its being sepa. monicated directly with each other; and rated with the potassium in the form of in several trials, it was always found pyrophoric sublimate, which is always that fixed alkali separated in the glass produced wben potassium is electriced negatively electrified; and that a very mi and converted into vapour in ammonia. nute quantity of acid was observable in Mr. D. mentions other experiments: the glass positively electrihed: but whe- but after all, he candidly says, that the ther the acid was owing to impurities general tenor of these enquiries cannot which rise in the distillation with the be considered as strengthening in any the mercury, or to muriatic acid existing considerable degree, the suspicion which in the glass, Mr. Davy does not deter- he had formed of the decomposition of mine; he says, however, as common salt nitrogen. He stated all the strong ob perfectly dry, is not decomposed by jections that occurred to him against the silex, it seeins very likely that muriatic mode of explaining the phenomena, by acid in its arid state may exist in coinbi- supposing nitrogen decomposed in the nation in glass.

operation; but, at the same time, obMr. Davy vext states the results of serving that they must not be considered the investigations which he had made ws decisive on this complicated and obe on the production of nitrous acid and scure question; and he adds, the opposite ammonia, in various processes carried view of the subject may be easily de on by himself, and then proceeds to fended. notice some attempts which he made to The professor next treats of the dedecompose nitrogen by agents, which he composition of aminonia; and, in refe. conceived might act at the same time on rence to former experiments, be says, the oxygen, and on the basis of nitrogen, production of an amalgam from ammonia, Potassium sublimes in nitrogen without which regenerated volatile alkali, appaaltering it, or being itself changed, and rently by oxidation, confirmed the notion he suspected that the case inight be of the existence of oxygen in this sub, different, if this powerful agent were stance, at the same time it led to the made to act upon nitrogen, assisted by suspicion, that of the two gases sepa the intense heat and decomposing ener- rated by electricity, one, or perhaps gy of Voltaic electricity. The experie both, might contain metallis matter ment was tried: the phenomena were united to oxygen; and the results very brilliant; as soon as the contact of the distillation of the fusible sub. with the potassium was inade, there was stance from potassium and aminonta, always a bright light, so intense as to be may probably be explained on such a paiuful to the eye : tbe platina used, supposition, lle has made a number


of experiments upon the decomposi- matter existing in the amalgam of ammo. tion of considerable quantities of an- nia? and what is the metallic basis of the mnonia, in which nothing was present volatile alkali? These are questions not but the gas, the metals for conveying easily solved; but Mr. D. says, that, in the electricity, and the glass'; and every his former communication on the amal. possible precaution used to prevent error; yam of ammonia, he stated, that, under and in all instances it was found, that all the common circumstances of its there was no loss of weight of the appa- production, it seems tv preserve a quan, ratus, nor any deposition of moisture tity of water adhering to it, which may during or after the electrization, but the be conceived to be sufficient to oxidate wires used were uniformly tarnished; and, the metal, and to re-produce the am. jo one instance in which surfaces of monia. He is even unable to form it brass were used, a small quantity of from ammonia in a dry state; neither olive-coloured matter formed on the the arnalgams of potassium, sodium, or metal; but though in this case nearly barium, produce it in ammoniacal gas; eight cubical inches of ammonia were and when they are heated with muriate decomposed, the weight of the oxidated of ammonia, unless the salt is moist, matter was so minute as to be scarcely there is no metallization of the alkali. sensible. In these experiments the in- The amalgam, which he has reason to be crease of gas was uniforınly from 100. to lieve can be made most free from ada 185, and the hydrogen was to the nitro. hering moisture, is that of potassium, gen in the average proportions of from mercury, and ammonium in a solid state: 7974 to 27-26; and assuming the com. this decomposes very slowly, even in mnon estimations of the specific gravity contact with water, and when it has of ammonia, of hydrogen, and nitrogen, heen carefully wiped with bibulous paper, Mr. Davy's former conclusions are sup- bears a considérable heat without alte ported by these new experiments: as ration. The ratio between the hydrogen they were also when the relative specific and ammonia produced from the amaigravities of these gases were taken with gam; is taken as one to two; and if this the utmost degree of precision possible, be accurate, then it will follow, that by means of the delicate balance belong. ammonia, supposing it to be an oxyde, ing to the Royal Institution. The speci- must contain 48 per cent. of oxygen, fic gravities thus taken are,

which will agree with the relations of Nitrogen, 100 cubical inches - 29.8 grains the attractions of this alkali for acids to

- 2.27

those of other salifiable bases. If byAmmonia . . . . . 1864

drogen be a simple body, and nitrogen

droven ha a simnle body and nitro The lately-discovered facts in chemis. an oxyde, then on the bypothesis above try, says Mr. Davy, concerning the im• stated, nitrogen would consist of nearly portant modifications which bodies may 48 of oxvgen and 34 of base: but if hyundergo by slight additions or subtrace drogen and nitrogen are both oxydes of tions of new matter, ought to render us the same metal, then the quantity of cautious in deciding upon the nature of oxygen in nitrogen must be less. These the process of the electrical decompo- views are the most obvious on the antisition of ammonia. It is possible, he phlogistic hypothesis of the nature of adds, that the minute quantity of oxygen metallic substances; but if the facts which appears to be separated, is not concerning ammonia were reasoned upon, accidental, but a result of the decon- independently of other chemical phenoposition, and if hydrogen and nitrogen mena, they inight be more readily.exe be both oxydes of the same base, the plained on the notion of nitrogen being possibility of the production of different a base, which became alkaline by comproportions of water, in different ope- bioing with one portion of hydrogen, and tations, might account for the variations metallic by combining with a greater observed: but on the whole, the idea proportion that ammonia is decomposed into hy. The solution of the question concerne drogen and nitrogen alone by electricity, ing the quantity of malter added to the and that the loss of weight is no more mercury in the formation of the amalgam than is to be expected in processes of so depends on this discussion: for if the delicate a bind, is in his opinion, the phlogistic view of the subject be adopted, most defensible view of the subject. The ainalgain must be supposed to con. But it will be askerl, If ammonia be ca- tain nearly twice as much matter as it is pable of decomposition into nitrogen and conceived to contain on the hypothesis hydrogen? What is the nature of the of deoxygenation, Mr. D. did formerly



[ocr errors]
[ocr errors]
[ocr errors]

rate it at the robooth part only, but this results, yet he conceires that they may is the least quantity that can be assumed, not be devoid of useful applications. It the mercury being supposed to give off does not scem improbable that the pas. one-half its volume of ammonia; and he sage of steam over hot manganese, may is now inclined to think it may contain be applied to the manufacture of vitrous the Telegth of new mpatter on the anti- acid: and there is reason to believe that phlogistic theory, and about oth on the ignition of charcoal and potash, and the pblogistic theory. The professor their exposure to water, may be adrane concludes this part of his subject by ob- tageously applied to the production of serving, that though the researches on volatile alkali, in countries where fuel is the decomposition and composition of cheap. nitrogen, have produced only negative (To be concluded in our next.)

MONTHLY RETROSPECT OF THE FINE ARTS. The Use of all New Prints, Communications of Articles of Intelligence, sc. ang

requested under COVER to the Cure of the Publisher.

Mr. Landseer's Observations on ebe Plan of the which the title-page promises; and we are Chalcograpbic Society.

deluded (after porchasing this plan to FEW months ago, the writer of improve our stock of knowledge in planA the monthly Retrospect in this Ma- ning, ) with an intimation, that be bas gazine, thought it necessary to speak in reserved it for the private inspection of praise of a plan submitted to the public such gentlemen as may chuse to consult for improving the art of engraving in him. We njarvel he did not add, acEngland by the Chalcographic Society: companied with the fee of a Bank of and neither the ill-natured reinarks of England note. If we believe the very Mr. Landseer thereon, a re-consideration modest Mr. Landseer, it would seen of both pamphlets, his own commen- that all talent, and all wisdom, is centred datory article, nor the patronage the in himself, and that no share whatever scheme has received, induces him to belongs to the respectable men who forin alter his opinion. The circumstances the society he opposes; and because they that led to Mr. Landseer's ill-tempered love quiet and attention to their art, bet letter on this praise-worthy society, and ter than those disputes and bickerings bis illiberal, ungenilemanly, abuse of some that must be the consequence of admitof its members, are briefly as follows, and ting into their society a man, who was which are here inserted in support of the justly defined, a short time since, by an former observations offered on the pub artist of high rank aud talents, as a " lito lished plan of the Chalcographic Society. tle man who is always vexed." It is Mr. Landseer was proposed, at his own truly astonishing and lamentable, that request, to be a member of the society, a man of Mr. Landseer's talents as an and rejected at the ballot. In the spleen engraver, should desert bis burin for of his disappointment, he published the the pen, and enter into unprovoked hos pamphlet naw under consideration. Its tility against his contenporaries. 11 15 object appears, from the title-page, to be a misfortune even for the public, but a fair observations on the plan; but its real greater to himself; for its consequences objects are the excitement of mistrust must recoil upon him. He would do well Rnd disunion between the members of to consider that, before be so broadly at« the Society for the Encouragement of tacks tlie characters of others, that his own the Art of Engraving," and those of the is not of that unsullied nature that will " Chalcographic Society;" to thwart the put him out of the reach of retaliation: views of the latter by misrepresentation let him remember the old Spanisli proand calurny: and to distract the former verb: That he who bas a house of glass, in the exercise of their patronage, by a shuld not begin to throw stones at bis confusion of doubts and scruples.

neighbour's." The letter (for so it is called, although Essays of rbe London Arcbitecterai Society no name is given to whom it is addressed) Published by order of obe Society. Twylor, is a curious specimen of absurdity, spleen, Holborn, malignity, and, we might say, falsehood; This is the second volume of essays by for we in vain look for the view of im- a Society of gentlemen, who have ilcor proving their scheme of patouage," rated themselves for the mutual study


and improvement of this branch of the siderable ability; and, as the conclusions" Fine Arts. The first essay iş by the pre- are the result of practice, there can be sident, (Joseph Woods, jun. F.L.S.) on no hesitation in recommending it to the modern theories of Taste, and is rather a attention of the profession at large. D. Teview of Allison, Burke, Price, and The Arcbitectural Antiquities of Great Britain, Knight's theories, than an original pro displayed in a Series of Engravings, with an Sect. The author combats soine, and

bistorical and descripiive Account of each Sub. argues ably on others, of the ingenious, ject. By foon Britton, F.S. A. Part 11. but too fine.drawn, speculations of mo. No. IV. of Vol. III. Longman and Co. dern theorists. This essay adds consider Taylor, and obe Author. ably to the general stock on this undefi- This is the fourth Number of the third ned, and perhaps undefinable, feeling; but volume of this very useful work, both it is not so closely applied to architecture, to the architect and the antiquary. The as might have been expected from a pro. plans are architecturally faithful, and the fessor in the art. The second essay is views at once scientific, useful, and picby Mr. Sarage, (vice-president), on turesque. This Nuinber contains seven Bridge-building, and displays much know- engravings, from St. George's Chapel, ledge of the subject, and sound reasoning. Windsor, viz. 1. A View of Beauchamp's The theories of Dr. Hutton, Mr. Alte Monument, &c. 2. Fine Specimens wood, and the Encyclopedists (in Dr. of Groining, &c. 3. Groinings over the Rees's edition) are carefully and ably organ screen to the Great Western examined, and their defects boldly Window. 4. The Great Western Wine pointed out. Mr. Savage, as might be dow. 5. Fitzwilliam's Monument. 6. expected from a practical architect, South-west view of the Chapel. 7. In. (which Dr. Hutton expressly declares his terior View of the North-aisle: which last treatise not to be written with the feel is one of the most beautiful specimens ings of) gives examples as well as pre- of perspective engraving, particularly cept; but, as only part of his essay is the distance, which has appeared for å printed in this volume, a close investi., long time, and reflects great credit on gation of the author's principles must be Mr. 11. Le Keux, the engraver. deferred till its conclusion. The next and

INTELLIGENCE. last essay is on Foundations, by Mr. James Elmes, (vice-president), in wbich this The Arts have sustained another loss fundamental branch of architective skill, of an able son, and the Royal Acadeiny 23 practised by the greatest architects, of a worthy member, in Mr. Zoffanij, who is brought to the test of practice, and as “ shuffled off his mortal coil" in the be. boldly condemned where he considers, ginning of last month. Johann Zoffanij, theni erroneous. This is a practice esq. R.A. (sometimes called Sir Johann that deserves commendation, and should Zotranij) portrait and historical painter, be oftener done; for great names often was born at Frankfort; and arrived in countenance great'errors. Of the inten-, England to study the arts, about the tion and contents of this highly-useful year 1764, and suffered much from po. essay, Mr. Elmes shall speak for hinn verty and want of encouragement; from self in the following quotation. “Having which state he was rescued by lord Bare thus quoted the opinions of soine archi- rington, wliose portrait he painted.. tects, whose practical and theoretical Shortly after this he visited Italy, with knowledge have procured them the just recoinmendations from his Majesty to the distinction of masters in the science, I grand duke of Tuscany; and while at shall proceed in the first section of the Florence, he painted bis celebrated pic. following essay, (by way of suminary,) to ture of the Florence Gallery, He altere collect them to a focus, which I shall wards returned to England, which lie denoininate the Ancient Practice. In left for India, where he received much the second, to narrate my own method encouragement; and has of late lived in in common cases, detailing some diffi- privacy. The style of Zoffanij's works, culties that have occurred, with the are truth of expression, a fine deep tone Methods used to overcome them, and the of colour, and high finishing in the de. event of their success. And in the tail. His principal works are portraits of third, a compendium of rules drawn dramatic perforniers of the time of Gare from the above sources, wirich I shall rick, King, Shuter, &c.; a picture einfcall the Modern English Practice of bracing portraits of all the incinbers of forming Foundations." These investiga. the Royal Academy; a similar one of tions the author has executed with con. the Royal Family, &c. MONTHLY MAG, No. 206.

3 L



On Monday, the 19th ult. Mr. Carlisle that he has included Sir Joshua Rey. commenced his course of anatomical nolds among the old masters, who can. lectures at the Royal Academy, which not possibly suffer by the connexion. shall be noticed in our next; as shall be At the annual meeting of the Royal the Rey. Mr. Foster's new Number of Academy, on the 5th ult. Mr. G. Are his elegant selection from the works of nald, landscape painter, was elected the best masters; and we are glad to sce Associate.


NR. MICHAEL SHAXnon's, (BERWICK• of the cock and pipe, and by tliis means

STREET, LONDON,) for Improvements the wort is kept bot, and repeatedly pase , in the Art of Brewing.

sed through the grain until the strengih IN the specification, giving an account of the inalt is entirely extracted. Aud

1 of these improvements, we have out. whenever it may be found necessary and kned drawings exhibiting representations expedient to cause the water, liquor, or of the machinery, seen on ditlerent sides. wort, to pass down the infusing vessel Froin the lower part of the copper is a instead of upwards, it will then be only coinmunication, through a cock and pipe, necessary that one set of cocks should be into a box or chamber from which there shut, and another set opened, and in that are five communications, viz. one through situation the heated water will be forced a cock to empty it; another to the bottom up the pipe, and downwards through the of the infusing vessel to draw off the con- vessel; out of which it will pass into the tents; another to the top of the infusing boiler, by a reverse operation; in this vessel; one with a pump, worked by the case, it will be needful to keep the cock first mover; and another with the air shut, until the infusing vessel is filled with vessel, which keeps up a constant re-action liquor. By these improvements, the when required. The infusing vessel may wort may be made as strong as the probe made of different forms and materials, portions of materials will allow; the inbut it is recommended, by way of prefer- convenient and inperfect operation of ence, that it should be cylindrical, and of mashing is avoided, and the sprout, or wood, and it is to be provided with two exhausted grain, may be afterwards false bottoms, or perforated partitions, drawn out with great facility and saving one near each extremity, for the purpose of labour. A like apparatus may be of allowing the liquor or wort to pass applied for passing the wort through more freely into and out of the same, hops, instead of boiling, in case the same during the time of operating. The pro- should be preferred, either for purposes cess is described as follows: Malt is put of economy, or giving a peculiar strength into the infusing vessel, which in most or difference of favour to the liquor by cases may be filled, or nearly filled, with this method. the same, excepting between the false bottoms or perforated partitions and the MR.CHARLES WILLIAMS'S, (GRAVEL-LASE, end thereof, and the water is to be put in LONDON,) for a Machine für Grinding due quantity into the boiler, and beat ape Mall, 8c. plied as usual. When the water is sutli. The machine, or mill, used on this 00ciently hot, it is to be so applied by means casion, is composed of a cylindrical or of the cocks and pipes above described, conical roller, made of cast iron, or any that it will rise through the malt to the other inetal, with grooves cut in it in an level in the boiler ; but it would not pass oblique or parallel direction: this roller through if it were not for the purp, which acts against loose knives, made of har. is, at the same time, to be worked by any dened steel, and screwed together so as adequate and convenient first mover, to form the same curve as the roller. and it draws the water through a lower These loose knives, or cutters, may be valve; and, at its returning stoke, forces taken out and ground, or sborpener, at ie through an upper ralse, placed within pleasure. In the margin of Mr. Willie the receptacle on each end of the barrel. ams's specification, is a drawing of the By Nis action the hot water is forced elevation of the mill. The roller is pus gradually through the malt in a constant in motion by a steain-engine, or any other strerin, the air escaping through a pipe, power; wlich roller acts against the which returns through the boiter by means knives or cutters, fixed in a parallel (


« ZurückWeiter »