Obrazy na stronie
PDF
ePub

132

Miscellaneous-Answers to Correspondents.

CHEMICAL NEWS,

Sept. 15, 1865.

SECTION B.--CHEMICAL SCIENCE.

ing papers were read after the delivery of the President's vessel a mineral substance. This substance was produced, Address :

and pronounced by two surgeons, who are members of the Committee, to be a kind of aluminous earth. It was

resolved that the substance be sent to an analytical H. C. Sorby-On a new form of Spectrum Apparatus as

chemist for inspection. The average import of Dutch applied to the Microscope. F. A. Abel-Notes on Compounds of Copper and Phos- yeast in Hull is about 7000 baskets per fortnight, and

during the past fortnight 123 baskets of yeast had been phorus. Dr. A. Voelcker-On the Composition of a Marine Boiler said the Board had no power to interfere with the adultera

destroyed as unfit for human consumption. The chairman Deposit.

tion if it could not be proved deleterious. If the substance Dr. T. Phipson-On Silicium in Iron. Dr. T. Phipson - On the Sublimed Oligist of Vesuvius take prompt steps to remedy the evil.

on analysis was found to be injurious, the Board would and its Artificial Production. Dr. T. Phipson

A few words on Sponges as a Source of North London Industrial Exhibition.-Among Bromine and of Nitrogen.

the rich displays of optical instruments at the Agricultural Dr. Angus Smith-On a Method of Estimating Carbonic Hall, the first that will attract notice is the large case of Acid in the Air, with Apparatus.

Mr. T. Ross. This contains a selection of telescopes, Dr. Williamson - Report on the Analysis of the Gases microscopes, and photographic lenses of that excellence evolved from the Bath Waters.

and finish for which the maker is famous. Among the F. Crace Calvert-Notes on the Action of Acids on some photographic lenses are some speciniens of the new actinic Metals and Alloys.

large-angle doublet, of which we may speak more particuDr. J. E. de Vry-On the possibility of Manufacturing larly since some pictures hanging beside the case, and Neroli in the B.itish Colonies.

others in the gallery upstairs, are exhibited to show the Orocn Rowland-On the Properties of Parkesine, and its capabilities of these lenses. We may say, shortly, that

Application to the Arts, Manufactures, and Telegraphy, the marvellous beauty of these pictures has never been F. G. Finch-On the Utilisation of Blast Furnace Slags. equalled. As the name implies, the doublet is remarkable Dr, A. Voeloker-On recently-discovered Phosphatic De- for the very wide angle of view it embraces. This is well posits in North Wales.

shown in the views of different courts in the Crystal Dr. Frankland-On the Constitution of the Acids of the Palace, which could only have been taken by a lens of Acetic, Lactic, and Acrylic Series.

this kind; and the special adaptation of the lens for taking Professor Wanklyn-Report on some of the Differences buildings will be at once apparent to the photographer, between the Normal and the Beta Alcohols.

who will further remark the sharpness of definition to Dr. D. S. Price-On the Action of Light upon Sulphide the very edge of the pictures. Famous as Mr. Ross has

of Lead, and its ring upon the Preservation of been as a maker of lenses, this last is certainly his most Paintings in Picture Galleries.

valuable contribution to the art of photography. The Report of the Committee on Gun Cotton.

visitor should particularly notice the copy of a map of Manning Prentice-The Progress of the Manufacture of France made with the doublet, as sharp, clear, and legible

Gun Cotton and its application to Mining, Military, and as the original engraving. Mr. Ross also exhibits one of Sporting Purposes.

Monckoven's enlarging apparatuses, with specimens of unw. L. Scott-On Action of Alkali Metals on Gun Ctton. touched pictures taken by means of it. "M. Dallmeyer W. L. Scott-On Arseniuretted and Antimoniuretted exhibits a case of photographic lenses, well made, of Hydrogens.

course, but including nothing novel. Mr. How has an Smyth, J., jun.-On an Apparatus for the determination extensive display of all kinds of apparatus, among which of Ozone, and experiments made therewith.

is the only spectroscope in the Exhibition. This is an Dr. de Vry-On the Rotatory Power of several Essential excellent instrument, of Bunsen and Kirchoff's form, and is Oils.

a very useful and cheap piece of apparatus. Mr. How Dr. Macadam-On Esparto Fibre, or Spanish Grass, and also exhibits a student's microscope, a very well-made its employment in the manufacture of paper.

instrument, with sliding stage and rapid and slow motion Dr. Macadam-On the Results of Agricultural Experi- to body, two eye pieces, and a quarter and one-inch object ments made in 1864.

glasses of excellent quality. There are besides a D. Forbes-On some Minerals from South America. On condenser, live-box, and other additions, which make

the Colour of Gold as seen by transmitted light. this an exceedingly cheap instrument. Some useful little T. Fairley-On the Reactions of Cyanogen. Note on chests containing blowpipe tests for mineralogists are Glycocine, with tables.

shown, and a delicate pocket aneroid compensated for the Sanitary Committee of the Hull Board of Health, held deserve a notice as exceedingly useful for educational purAdulteration of Dutch Yeast.-At a meeting of temperature for travellers. Some models of crystals in

glass, showing the primary and included forms, also on Wednesday, the chairman stated that his attention had poses. Several other cases in this interesting exhibition been called by an anonymous letter to the adulteration of yet require a notice, but these we must reserve for another Dutch yeast. The letter stated that the recent importa- occasion. tions of yeast contained a large admixture of China clay, which was ground as fine as flour by a machine. The chairman remarked that this kind of adulteration occurred

ANSWERS TO CORRESPONDENTS. a few years ago, and he had reason to believe that it was again being extensively practised. The same anonymous correspondent had again written to him to say that two D. T. 0.-Melted sulphur and sand. importers at Bradford had written to the agents on the H. F.-Treatment with sulphuric acid and bichromate of potash Continent, telling them that it was very likely that the would probably affect the firet object; for the

second, what you sugwhole of the next importation would be seized unless the gost would probably answer. Try a greenish oil. quality was improved, and there was an improvement in for and give it next week. 2. Subscribe to the Meteorological Society,

M. A. W.-1. A process does not occur to us now, but we will look the next cargo. The inspector stated that the cargo wh forward reports. spoken of as improved was one of the worst samples that Books Received." Practical Treatise on Coal, Petroleum, and other had been sent to Hull for some time. He had made in Distilled Oils,” br G. A. Gesner, second edition; "Scientific Review; quiries, and had collected samples, some of which he had Dictionary of Chemistry," Part XXX.

“Proceedings of the American Pharmaceutical Association, 1864;" dissolved in water, when there sank to the bottom of the Received. --Thallium.

}
British Association.

133 Sept. 22, 1885. BRITISH ASSOCIATION.

foremost of them all, James Watt, who here diversified his engineering labours with his famous investigations

into the composition of water. It was at the factory at Address to the Section of Chemistry, by the President, Soho, too, that Murdoch made the first great experiment

Professor W. A. Miller, M.D., LL.D., Treas. and on gas-lighting, at the illuminations for the short-lived V.P.R.S., President of the Chemical Society.

peace of Amiens; and it was in Birmingham that Dr. INTERESTING historical associations are naturally Roebuck, in the middle of the last century, erected the awakened in the mind of the chemist as he enters upon first leaden chamber for the making of sulphuric acid, the business of this section of our scientific gathering in and thereby inaugurated the most important of the chethe town whose hospitalities we are now sharing; for mical manufactures of this country. he is reminded that on August 1, 1774, only ninety-one Nor has Birmingham failed in more modern times to years ago, Priestley laid, at Birmingham, the foundation maintain her reputation in connexion with the chemical of modern chemistry, by the discovery of oxygen. arts. Here, twenty-five years, ago, Elkington founded

Yet it seems difficult to realise the fact that there the first establishment, in this country, for carrying out must be some still living who entered life when the the processes of electro-plating and electro-gilding, chemical nature of the atmosphere was undiscovered, Here Askin made the nickel of commerce, with its comwhen water was believed to be an elementary substance, panion metal, cobalt, as oxide-articles that might vie when the composition of the ordinary acids, nitric, in purity with the products of the laboratory. Here hydrochloric, and acetic, was unknown, when the dis- Chance has established a manufactory of optical glass coveries of Galvani had not been made, and when the which specially calls for acknowledgment on the part battery which perpetuates the name of Volta did not of the student of science; and here Sturge and Albright exist.

have erected the only manufactory for red phosphorus It requires a considerable mental effort to estimate which the country contains. aright the extraordinary progress which chemistry, both Vast as is the modern development of experimental in its scientific and in its practical aspect, has made since science, it yet cannot excite much surprise that, with the that day.

exception of that portion which falls within the domain For example, the development of the laws of combi- of the mathematician, science until recently has been nation-the determination of the equivalent proportions systematically excluded from the general course of eduof the elementary bodies--the art of chemical analysis cation, and has been followed in the majority of instances the atomic theory-the isolation of potassium, with the by those only who commenced its study for professional consequent discovery of the compound nature of the objects. Yet can we wonder at this, when we remember alkalies and earths-and the marvellous developments of that the science of chemistry and many entire branches the organic department of chemistry, exhibit some of of experimental physics, including voltaic electricity, the most striking points in the progress of the science ; electro-magnetism, thermo-electricity, the phenomena of whilst in the chemical arts we may mention gas-lighting polarised light, of photo-chemical action, radiant heat, - the manufacture of stearic acid and other fatty acids and others, are, as already stated, less than a century for candles-the industry of petroleum and paraffine- old ? But the great strides that they have made in that the chemical process of bleaching by chlorine-the pre-interval, the social changes that they have introduced, paration of carbonate of soda from common salt, and the and the additional powers that they have conferred upon extensive alkali trade. The discovery of iodine and man, will vindicate their importance as necessary branches bromine, and their varied applications as remedial agents of knowledge to be acquired; whilst the more just and otherwise--the fascinating processes of photography appreciation of the methods of investigation which they —the developinent of the trade in beetroot sugar--the pursue will establish their claim to be regarded as instruextraction of quinia, morphia, and all the vegetable ments in training the mind, and shaping the intellectual bases,--these and other processes of chemical manufac- development of the future. ture too numerous to mention, are all subsequent to, and Those whose education was based upon the linguistio may be said to be in nearly every case consequent on, the system almost exclusively, as was the case both before great discovery of oxygen.

and after Priestley's time, could not be expected to Well may we sympathise, now, in the sanguine anti-realise the magnitude and true bearing of science and its cipations of Priestley himself, expressed in the preface educational value. Now, however, the case is altered ; to the volume in which this discovery is recorded, " Ex-and it is a subject for congratulation to reflecting men periments and Observations on Different kinds of Air," that the introduction of the scientific element into the vol. ii., p. 7:-"In reality, this is not now a business of ordinary course adopted at our public schools is at length air only, as it was at the first; but appears to be of much attracting serious attention, and that its importance has greater magnitude and extent, so as to diffuse light upon been insisted on in both Houses of the Legislature. The the most general principles of natural knowledge, and practical instinct of the nation is becoming alive to the especially thosc about which chemistry is particularly necessity of making certain portions of the training of our conversant. And it will not be now thought very assum-youth consist in the systematic study of the elementary ing to say, that, by working in a tub of water or a basin parts of properly selected branches of science; and it of quicksilver, we may perhaps discover principles of behoves all who are themselves engaged in the pursuit of more extensive influence than even that of gravity itself, science to consider in what way they can themselves aid the discovery of which, in its full extent, contributed 80 in forwarding this object. much to immortalise the name of Newton."

I need not here advert to the exploded notion that But it is not alone with the name of Priestley that we the acquisition of the truths of science can in any wise associate the progress of chemistry in Birmingham. endanger those of revelation ; for truth is ever consistent. Grouped around the father of pneumatic chemistry were But it may not be superfluous to reassure the minds of several remarkable men who then either resided at Bir- some who imagine that science, like a fresh invasion mingham or frequently met there, including Matthew of Vandals, will extinguish scholarship and classical Boulton, James Keir, Dr. Withering, Dr. Darwin, and, I learning. Language must indeed ever form the basis of

VOL. XII. No. 303. SEPTEMBER 22, 1865.

134

British Association.

CAKMICAL NEWS,

Sept, 22, 1865.

our system of education; for it is the key that unlocks wisdom, to place themselves at the head of this new the stores of knowledge; and no languages are so fitting movement, which is destined to exercise so wide an influto form the groundwork as the tongues of ancient Greece ence upon the education of our people. and Rome, irrespective of the treasures of philosophy, But it is time that we proceed to take a rapid survey eloquence, poetry, and history which they contain. They of some of the principal points in the progress of chehave that intellectual finish and completeness which mistry during the last twelve months. The course of belongs only partially to science. A moderate amount chemical discovery since our meeting last year, though of classical knowledge can be, as, indeed, it ought to be, not marked by any very striking novelty, has nevertheattained by every so-called educated mind, while for him less been steadily advancing. Ideas previously thrown who would carry the critical faculty to a high state of out have been discussed and developed, and many of cultivation, the study of the classics affords the means. them are leading to new discoveries, or are being applied These tongues constitute the basis of many of the modern to explain phenomena before wrapped in obscurits. European languages; and an acquaintance with their Amongst the problems which have, for some time literature imparts a cultivation and a polish that it is past, been engaging the minds of philosophical chemists, almost vain to seek from any other source. Just as some few are of greater interest than those connected with minds seek to attain distinction in the wide domain of the idea of the atomicity of the elements. It is well philology, other minds, as vigorous, though differently known that chemists now distinguish between the constituted, delight in the study of natural laws and atomic weight and the equivalent of an element ; also, affinities. It would be a hard thing to say that provi- that owing to the labours of many distinguished men, sion should not be made in our schools for the latter, as amongst whom the names of Williamson, Kekulé, wide and liberal as it has been for the former.

Odling, Cannizzaro, and Wurtz are the most prominent, It is not to be supposed that, because science is to form a classification of the clements into families has been a part of the education of every gentleman, therefore it made; and that this classification rests upon what is will constitute the pursuit of his mature years. What known as the atomicity of the elements. One group is needed is that he possesses sufficient knowledge of its of the elements, like potassium and chlorine, is regarded principles to qualify him to appreciate the advances as monatomic, or usually equivalent in functions to one which science is making, and to enable him to contribute atom of hydrogen; a second, like oxygen and sulphur, intelligently towards its progress.

is diatomic, or equivalent in functions to two atoms It is certain that if science is to form a useful portion of hydrogen ; a third group, like nitrogen, phosphorus, of the education of a boy, it must be undertaken with and arsenic, is triatomic or equivalent for the most part the determination to deal with it as a matter of study: to three atoms of hydrogen ; while a fourth group, the same pains must be taken to ascertain that each boy like carbon and silicon, is tetratomic, or equivalent in understands the principle, for example, of the air pump, functions to four atoms of hydrogen, and so on. or the meaning of the thermometric scale, as that he It would lead us too much into detail, were I to comprehends a rule in syntax or the analysis of a sen- attempt to show how this idea of the atomicity of the tence. To do this, however, the instruction given must elements has been applied, and is still in process of not be limited to a dıy lecture on the principles of some application, to the study of the formation of compounds branch of science once a week. These principles must in general, how it endeavours to explain the esistence be logically unfolded, and illustrated, when necessary, of a limit to their number, and how it even teaches us by experiments, and the structure of machines and to anticipate their possible varieties. apparatus explained by suitable diagrams; the boys Among the subjects connected with its development must be taught to take notes of each lecture ; and the is its bearing upon isomerism, or the remarkable fact of ground covered must be made secure by following up the existence in many cases of two or more bodies of the lectures with frequent examinations, both oral and different properties but yet composed of the same elewritten. These are as necessary to the successful study ments combined in identically the same proportions. of a science as the writing of exercises, or the practice Upon this subject, which, at our last meeting, was chaof construing, is to the accurate study of a language. racterised by Dr. Odling as the chemical problem of the Science is not merely to supply her facts; she is to be day, a suggestive theoretical paper was published, about employed to develope the powers of the mind, and to twelve months ago, by Dr. Crum Brown; whilst, in the discipline them for action. Hence it is of far more im- same direction, Cahorrs, Kekulé, Beilstein, Fittig, and portance to instil principles, and to cultivate precision several other chemists have published valuable experiin observation, in thought, and in description, than it is mental researches. Inquiries of this kind are now to load the memory with mere facts, however valuable. acquiring special importance from the numerous cases In short, the system of cramming is to be eschewed, of the formation of such isomeric bodies by the methods whilst the formation of habits of comparing, reasoning, of synthesis and substitution, which are daily muland judging is to be encouraged in every way.

tiplying: It may at first be difficult to meet with well-trained Closely connected with the same subject are the inves. and competent teachers; but when once the want of in-tigations into the constitution of the more complex struction in science is proclaimed, the teachers will soon organic acids, which have been prosecuted so actively be forthcoming. Some years will, no doubt, elapse ere during the last five or six years, and which, in the science is admitted to take equal rank, as a means of hands of Kolbe, Franklin, Perkin and Duppa, Kekulé, education, with the study of classical literature. Still Wurtz, and their pupils, have made such rapid progress. it is but a question of time ; and we cannot but hope During the past year Frankland and Duppa bare that our universities, following up the commencement especially signalised themselves by their researches which the youngest but not the least active amongst upon the lactic and the acrylic series. Two years ago, them, the University of London, has made in the esta- Frankland, commencing with oxalic ether, and acting blishment of degrees in science-we cannot but hope, 1 upon it with zinc ethyl, obtained from it leucic ether by say, that the heads of our universities will ere long feel substituting ethyl for a portion of the oxygen contained it to be their duty, as unquestionably it will be their in the oxalic ether; and afterwards, conjointly with his

CHEMICAL NEWS,

Sept. 22, 1865.

British Association.

135

Leucic acid.

Lencic or diethoxalic acid.

friend Duppa, he has generalised this reaction. Still An extensive bra ich of industry is now springing up more recently, these chemists have traced the connexion in the improved methods of voltaic depositions of the between the lactic and the acrylic or oleic series, by re. metals. Weil has, by the use of an alkaline solution of actions in which the abstraction of the elements of an tartrate of copper, contrived to coat iron and steel with atoin of water from the basylous portion of a member a tough closely adherent sheathing of copper, by simply of the lactic group converts it into the corresponding suspending the articles to be coated by means of a wire member of the acrylic series. These relations will be of zinc in the metallic bath. No battery is required. readily understood by representing the different com. Lead and tin may in a similar manner be deposited on pounds by symbols, as follows:

copper, iron, or steel, if the oxide of tin or of lead be Oxalic acid.

dissolved in a bath of strong solution of caustic soda.

I must, before I conclude, advert to one or two in(1) H,C,ent (,H) - - H,HC,(8,4,5,6, teresting additions to our knowledge upon the side

Ethylcrotonic acid.

where chemistry ard physics meet. Few results, per

haps, were more unexpected than those obtained by (2) 11€,(0,4),,-1,0-8,0,(6,4)(C,,)”O,.

Deville and Troost upon the permeability to gases of

certain dense metals at elevated temperatures. They In these and kindred investigations, the necessity have proved that platinum and iron, when white-hot, for the introduction of fixed principles of nomenclature become for the time porous, and are rapidly permeated for regulating the construction of names for the recently by hydrogen, which will even pass out under the discovered compounds has been sensibly felt; and in- pressure of the atmosphere and leave a vacuum almost deed the changes in notation rendered necessary by the perfect within the tube. In one form of these experi. alteration in the values assigned to the atomic weights ments, tubes of hammered and of cast platinum (which of many of the chemical elements have rendered a in one case was as much as a twelfth of an inch in general revision of the system of chemical nomenclature thickness) were fitted

by means

of corks into the axis of à matter of pressing importance. Probably few sub- a shorter and wider tube of glazed porcelain ; a slow jects could more usefully occupy a portion of the time current of pure and dry hydrogen was then maintained of this section during the ensuing week than a thought through the porcelain tube, whilst a current of dry air ful consideration of the changes which it may be expe- was transmitted through the platinum tube. At ordinary dient to introduce. The meeting of chemists from temperatures no change was observed in either gas. A various parts of Europe with many from distant parts fire was then lighted around the outside of the porcelain of our own country affords an excellent opportunity for tube, and gradually raised until the heat became very discussing a subject of this kind, where any conclusions, intense. Åt 20000 Fahr. the oxygen contained in the to be practically effective, must secure the concurrence of air had entirely disappeared ; nothing but nitrogen a majority of the active cultivators of the science. mixed with steam passed out of the platinum tube,

Did time permit, it would be easy to mention other hydrogen bad passed through the pores of the platinum investigations in the organic department of chemistry, and entered into combination with the oxygen of the scarcely less interesting than those already alluded to, air within ; whilst at still higher temperatures the moist such as those on the synthesis of the aromatic acids by nitrogen became mixed with hydrogen. As the tube Kekulé, who has prepared both benzoic and toluic acid cooled, the same phenomena occurred in the inverse by the graduated action of sodium on an ethereal solu- order, till, when the ordinary temperature had been tion of bromo-benzol

, and of bromo-toluol whilst sub- regained, no diffusion of hydrogen was perceptible, and mitted to a current of carbonic anhydride, as, for unaltered air was collected from the platinum tube. instance, may be explained by the equation

Analogous results were obtained when a tube of soft Bromobenzol. Sodic benzoate.

cast steel was substituted for that of platinum, though OH,Bro+ Na, + 60, ='Nat.H3(602) + NaBr.

the thickness of the steel tube was an eighth, or in some

cases as much as a sixth of an inch. or such as those of Maxwell Simpson and of Baeyer on From these experiments one practical conclusion the artificial formation of tribasic acids ; and, referring deducible is, that air-pyrometers, the bulbs of which are · to methods of research, stress might be laid on the im- formed of iron or platinum, cannot be relied on when portant aid afforded by the extended use of the amalgam employed for measuring elevated temperatures ; glazed of sodium as a reducicg agent, and on the similar but porcelain, however, was found to confine the gases constill more remarkable reducing effects of hydriodic acid pletely.

-processes, indced, not new, but the value of which Curious as these results are, they are but parenthetical till

quite recently has only been partially recognised. in another series of more general bearing, in which

Passing allusion only can now be made to some of the Deville has for some time been engaged — viz., the processes of mineral and metallurgic chemistry, such as phenomena of dissociation, as he has termed the partial ihe improvements in the details of the process for pre- decomposition which compound gases experience under paring magnesium, the comparative facility with which the influence of a temperature more or less elevated. the recently discovered metals thallium, rubidium, and A very striking result was obtained by the use of an cæsium and their compounds may be obtained, and the apparatus similar to that employed in the experiments application by Redten bacher of his observation of the just described, but in which a brass or silvered tube was sparing solubility of their alums to the extraction of the substituted for the platinum or iron tube. A rapid flow new alkalies from the lithium residues of commerce. Of of water was maintained through the metallic tube, so indium, too, the latest of the newly discovered metals that it was kept quite coul, whilst the outer porcelain revealed by the spectrum, it must suffice to say that it tube was gradually raised to an intense heat as b fore. has been obtained in quantity which places its existance Ou transmitting a current of pure and dry carbonic as a distinct metal beyond question. I am indebted to oxide through the porcelain tube, the lower part of the my friend Professor Roscoe for the small specimens of surface of the cold metallic tube became covered with the metal and its sulphide now upon the table.

deposited carbon, whilst a portion of the carbonic oxide,

136
On Some Salts of the Peroxide of Thallium,

Sept. 22, 1865. by combining with the oxygen previously united with pounds existed between nitro-ammonia acid, the subthis carbon, became converted into carbonic anhydride. stance acted upon, and the .est product of its reduction.

Sulphurous anhydride was by similar treatment re. One of these bodies Dr. Lossen had succeeded in isosolved into sulphur and sulphuric anhydride ; and even lating. It was a compound which, from its composition, hydrochloric acid was partially separated into hydrogen might be termed protoxide of ammonia, having, in fact, and chlorine. These experiments are intimately con- the formula H,NO. This substance, like ammonia, comnected with the attempts made to explain the cause of bined with acids, producing a series of magnificent salts certain exceptions to Ampère's law, that equal volumes remarkable for the facility with which they crystallise. of gases or vapours contain the same number of mole- The simplest method of producing this interesting comcules of each. Chemists now generally assume that the pound consisted in submitting nitrate of ethyl to the molecule, both of simple and of compound bodies, forms action of metallic zinc in the presence of an acid. It two volumes of vapour, and consequently that the mole- would be observed that the derivation of the new body cular weight of any substance corresponds with the from nitric acid was perfectly analogous to that of number which represents twice its density when re- aniline from nitrobenzol. ferred to the density of hydrogen, if this be taken as

Nitrobenzol,

Aniline. unity. But there are exceptions to this law: penta

C.H.NO,

CH,NH, chloride of phosphorus, hydrochlorate of ammonia,

Nitric acid.

Hydorylamine. hydriodate of phosphuretted hydrogen, and various

HO,NO,

HO,NH, other bodies, instead of forming two volumes when one The new body might be looked upon as ammonia, in molecule of each is converted into vapour, yield four which one atom of hydrogen is displaced by what might volumes.

be called the rump of water, the atomic group ło, In order to explain these anomalies, Kopp and Can- which by some had been called hydroxyl, by others nizzaro suppose that, at the temperature at which the hydoryl. papour-densities of these compounds are observed, the

Ammonia.

Hydorylamine. bodies are temporarily decomposed, and, instead of form.

H

HO ing one homogeneous vapour, are at the time of the ob

HN

H N servation really composed of a mixture of vapours. In

H

H certain cases this explanation is probably the true one ;

It was certainly interesting to see the simplest of but its general acceptance has been disputed by Deville reactions, familiar to every chemist, still yielding a himself, though his results on dissociation seem, to cur. harvest of such splendid results. sory observation, to be in its favour; and it must be admitted that, up to the present time, the arguments and experiments which he has brought forward in oppo

On Some Salts of the Peroxide of Thallium, sition to the views of Kopp and Cannizzaro have not The compounds of thallous oxide with acids have been

by A. STRECKER.* been satisfactorily answered.

No sufficient proof, for example, has yet been addaced for the most part studied and described, but little has that the well-known anomalous cases of nitric oxide, been said of the salts of thallic oxide (1103), except chlorous anhydride, hydrosulphide of ammonium,

that they are hygroscopic and easily decomposable. cyanine of ammonium, and various other salts of am. The author, therefore, prepared some of the salts, and monium and the volatile

bases are due to dissociation submitted them to investigation. He prepared the oxide of their components.

by adding hypochlorite of soda to a solution of thallous This subject is one, however, too intimately connected chloride in carbonate of soda. The two solutions, when with the molecular theories at present under discussion mixed in the cold, gradually deposited a brown preto remain long in its actual state. New experiments cipitate of thallic oxide, which was washed by decantaand evidence will no doubt be forthcoming, which will tion. A boiling saturated solution of thallous chloride throw further light upon the cause of these outstanding in carbonate of soda added to hypochlorite of soda gives exceptions.

a dark brown precipitate of thallic oxide, usually mixed with a small quantity of chloride, which may, however, be

changed into peroxide by digesting the precipitate with SCIENTIFIC AND ANALYTICAL hypochlorite of soda. CHEMISTRY.

According to Lamy, the peroxide precipitated by an

alkali from the perchloride retains, after drying at On a New Series of Bodies Intermediate between Nitric 100° C., one equivalent of water; but Strecker found Acid and Ammonia, by Dr. A. W. HOFMANN, F.R.S.

the entire loss, on heating the oxide to redness in a IN the course of a discussion on a paper read at the stream of dry air, was only 0:6 per cent. ; the formula Birmingham meeting of the British Association, Section T10, + HO would require 3'8 per cent. of water. B, by Ďr. C. Calvert “On the Action of Acids on some

Thallic Sulphate.-Thallic oxide easily dissolves in Metals and Alloys,"Dr. Hofmann asked Professor Calvert warm dilute sulphuric acid. On evaporating the soluwhether, in his experiments on the action of acids, and tion, thin, colourless plates separate from the concenmore especially of nitric acid, upon the metals, he had met trated liquor ; these must be collected on a filter paper with some of the extraordinary bodies lately observed and separated from the mother liquor by pressure; by Dr. Lossen. This young chemist, at one of the late washing with water decomposes the salt. Vried in the meetings of the Berlin Academy, had laid before that air, the salt has the composition T103,3SO3 + 7H0; at body an account of several substances which had 220° it loses six equivalents of the water, and becomes attracted general attention. It was well known that

T103,3SO3 + HO. among the products of the action of nitric acid upon tion of thallic

sulphate in dilute sulphuric acid added to

Sulphate of Thallic Oxide and soda.-A solu. certain metals ammonia invariably occurred. appeared that ammonia was only the last product of the a saturated solution of sulphate of soda gives colourless reaction, and that a whole series of intermediate com. * Abstract Annalen der Chem. und Pharik, Aug., 1865, p. 207.

« PoprzedniaDalej »