scholarly journals On the electrolysis of secondary compounds. In a letter addressed to Michael Faraday, Esq., D. C. L., F. R. S., Fullerian Professor of Chemistry in the Royal Institution of Great Britain, &c., &c. By John Frederic Daniell, Esq., F. R. S., Professor of Chemistry in King’s College, London

1843 ◽  
Vol 4 ◽  
pp. 153-155
Keyword(s):  
Relative Proportion ◽  
Secondary Compounds ◽  
Compound A ◽  
King's College ◽  
Small Constant ◽  
Royal Institution ◽  
Present Letter ◽  
The Subject ◽  
Michael Faraday ◽  
Made In

The discovery of definite electrochemical action naturally suggests the inquiry into the relative proportion of that part of a voltaic current, which, in the case of its decomposing a saline solution, is carried by the elements of the water, and that part which is carried by the elements of the saline compound, and into the definite relations, if any such there be, subsisting between the two electrolytes so decomposed. This question was the origin of the investigation which forms the subject of the present letter. The power which the author employed in this experimental inquiry was that of a small constant battery of thirty cells, six inches in height, with tubes of earthenware, charged in the manner he has described in his former communications to the Society. The result of the first experiment evidently indicated that the decomposition of one equivalent of water was accompanied by the decomposition of an exact equivalent of sulphate of soda. The author then endeavours to ascertain whether the power of the current is equally divided between what had hitherto been regarded as the two equivalent electrolytes. The first experiments he made in order to determine this point seemed to lead to the extraordinary conclusion, that the same current which is just sufficient to separate an equivalent of oxygen from an equivalent of hydrogen in one vessel, will at the same time separate an equivalent of oxygen from one of hydrogen, and also an equivalent of sulphuric acid from one of soda in another vessel. The author then examines the remarkable phenomena relative to the transfer of matter from one electrode to the other without the decomposition of the transported compound; a phenomenon which was first observed by Mr. Porret in glass cells divided into two compartments by a diaphragm of bladder.

scholarly journals XI. Second letter on the electrolysis of secondary compounds. Addressed to Michael Faraday, Esq. D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, &c. &c. &c. By J . Frederic Daniell, Esq. F. R. S. For. Sec. R. S., Prof. Chem. in King's College, London

1840 ◽  
Vol 130 ◽  
pp. 209-224
Keyword(s):  
Royal Society ◽  
Chemical Elements ◽  
Pure Water ◽  
Secondary Compounds ◽  
King's College ◽  
Usual Manner ◽  
Royal Institution ◽  
The Subject ◽  
Michael Faraday ◽  
Epsom Salt

My dear Faraday, You will not, I think, be surprised or displeased at my addressing you again upon the Electrolysis of Secondary Compounds . The whole of my very limited leisure, since my last Letter which the Royal Society did me the honour to publish in the Philosophical Transactions for 1839, has been occupied with experiments upon the subject; and I have obtained some results which I trust will not be found unworthy of the continued attention of yourself and the Society. The mode of investigation which I have adopted seems to me calculated not only to throw light upon the nature of electrolytes, but upon the mode in which the chemical elements group themselves together to constitute Radicles or Proximate Principles , the question which now seems universally to occupy the attention of chemists. I feel more than ever satisfied that the laws of electrolysis will be found to lead to the solution of this great problem. Upon reflecting upon the constitution of the oxyacid salts, as developed in my last Letter, I conceived that it might be possible to obtain further evidence that the simple cathion travelled as a metal to the platinode, while the compound anion was passing in the opposite direction; and that means might be devised of stopping it, as it were, in transitu . Your beautiful experiment, which I have often repeated with success, of precipitating the magnesia from a solution of Epsom salt against a surface of pure water, in the course of a voltaic current, suggested the mode of proceeding. According to my view of that experiment, the first electrolyte was resolved into the compound anion, sulphuric acid + oxygen, which passed to the zincode; and the simple cathion, magnesium, which on its passage to the platinode was stopped at the surface of water, from not finding any ion , by temporarily combining with which it could be further transferred according to the laws of electrolysis. At this point, therefore, it gave up its charge to the hydrogen of the water, which passed in the usual manner to the platinode; and the circuit was completed by the decomposition of this second electrolyte. The corresponding oxygen, of course, met the magnesium at the point where it was arrested in its progress, and, combining with it, magnesia was precipitated.

scholarly journals VII. On the electrolysis of secondary compounds. In a letter addressed to Michael Faraday, Esq., D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, &c. &c. &c. By J. Frederic Daniell, Esq. F. R. S., Prof. Chem. in King's College, London

1839 ◽  
Vol 129 ◽  
pp. 97-112 ◽  
Keyword(s):  
Experimental Research ◽  
First Principles ◽  
Secondary Compounds ◽  
The Other ◽  
King's College ◽  
Other Hand ◽  
Royal Institution ◽  
The Subject ◽  
Michael Faraday

My dear Faraday, I Have no doubt that you will agree with me in thinking that the decomposition of secondary compounds by the voltaic current, particularly in connexion with water, has not yet received all the attention which it deserves, and that the subject is worthy of further experimental research. When water is present in an electrolyte, you have yourself remarked that it is probable that it is always resolved into its first principles; and, on the other hand, the early experiments of Sir H. Davy prove that when saline substances are present in water, even in the minutest quantities, they are also separated into their elements, or into their proximate principles. Whether these simultaneous decompositions bear any relation to each other, has never, that I am aware of, been made the object of inquiry.

VI. Fifth letter on voltaic combinations, with some account of the effects of a large constant battery. Addressed to Michael Faraday, Esq. D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, &c. &c. &c. By J. Frederic Daniell, Esq. F. R. S., Prof. Chem. in King's College, London

1839 ◽  
Vol 129 ◽  
pp. 89-95 ◽  
Keyword(s):  
Royal Society ◽  
Conducting Surface ◽  
Conducting Sphere ◽  
Active Point ◽  
King's College ◽  
Royal Institution ◽  
The Subject ◽  
Michael Faraday

My dear Faraday, In my last letter to you, which the Royal Society have done me the honour to publish in the Philosophical Transactions for 1838, I observed, that “the principal circumstance which might be supposed to limit the power of an active point within a conducting sphere, in any given electrolyte, is the resistance of that electrolyte, which increases in a certain ratio to its depth or thickness.” The superficial measure of the conducting sphere, and the distance of the generating metal, or the depth and resistance of the electrolyte, are, in fact, the variable conditions in a voltaic combination upon which its efficiency depends; and their relations require further investigation before we shall be able to determine what may be the proper proportions for the economical application of the power to useful purposes. I shall venture, therefore, to trouble you with the results of some further experiments upon the subject, and upon different combinations of the constant battery, before I proceed to communicate some observations upon Electrolysis, which I trust you will find not without interest, and to which, according to my plan, my attention has been lately exclusively directed. Looking, for a moment, upon the affinity which circulates in the battery as a radiant force, it seemed desirable to ascertain what would be the result of intercepting the rays by the conducting surface nearer to their centre than in the arrangements which have been previously described, as the relation of the generating and conducting metals to each other might be thereby more clearly ascertained.

scholarly journals Second letter on the electrolysis of secondary compounds, addressed to Michael Faraday, Esq., D. C. L., F. R. S., &c. By J. Frederic Daniell. Esq., For. Sec. R. S., Professor of Chemistry in King's College, London

1843 ◽  
Vol 4 ◽  
pp. 231-231
Keyword(s):  
Chemical Elements ◽  
Secondary Compounds ◽  
King's College ◽  
The Subject ◽  
Michael Faraday ◽  
Acid Salts

The author, in this letter, prosecutes the inquiry he had commenced in the former one, into the mode in which the chemical elements group themselves together to constitute radicles , or proximate principles. He considers his experiments as establishing the principle that, considered as electrolytes, the inorganic oxy-acid salts must be regarded as compounds of metals, or of that extraordinary compound of nitrogen and four equivalents of hydrogen to which Berzelius has given the name of ammonium , and compound anions, chlorine, iodine, &c., of the Haloide salts; and as showing that this evidence goes far to establish experimentally the hypothesis originally brought forward by Davy, of the general analogy in the constitution of all salts, whether derived from oxy-acids or hydro-acids. Some remarks are made on the subject of nomenclature, and the rest of the paper is occupied with the details of the experiments, all bearing on the important subject which he has undertaken to investigate.

scholarly journals Further observations on voltaic combinations; in a letter addressed to Michael Faraday, Esq., D. C. L. F. R. S., Fullerian Professor of Chemistry in the Royal Institution, &c. &c. By John Frederick Daniell, Esq., F. R. S., Professor of Chemistry in King's College, London

1837 ◽  
Vol 3 ◽  
pp. 469-471
Keyword(s):  
Aqueous Solution ◽  
Electric Current ◽  
Sulphuric Acid ◽  
Hot Water ◽  
Common Salt ◽  
Influence Of Temperature ◽  
King's College ◽  
Royal Institution ◽  
The Subject ◽  
Michael Faraday

In the course of an inquiry on the effects of changes of temperature upon voltaic action, the author was led to observe some curious disturbances and divisions of the electric current produced by the battery, arising from secondary combinations; the results of which observations form the subject of the present paper. He found that the resistance to the passage of the current was diminished by dissolving the sulphate of copper which was in contact with the copper in the standard sulphuric acid, instead of water. The increased effect of the current, as measured by the voltameter, was farther augmented by the heat evolved during the mixture; and wishing to study the influence of temperature in modifying these effects, the author placed the cells of the battery in a tub, filled with hot water. On charging the cells with a solution of muriate of ammonia in the interior, and aqueous solution of sulphate of copper in the exterior compartment, he observed that a portion of the current is discharged by the water in which the apparatus was immersed; its passage being indicated by the disengagement of gas betwixt the adjacent cells, in which case, one of the zinc rods is thrown out of action, and the copper of that cell acts merely as an electrode to the antecedent zinc. A saturated solution of common salt was next placed in contact with the zinc, while the exterior compartments of the cells were filled with a saturated aqueous solution of sulphate of copper; but the effects were much diminished. It thus appeared that the substitution of solutions of the muriates for dilute sulphuric acid was in every way disadvantageous; and it was moreover found that, when the circuit was broken, the copper became seriously injured by their action, and by the formation of a submuriate of that metal.

scholarly journals VIII. Sixth letter on voltaic combinations. Addressed to Michael Faraday, Esq., D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, &c. &c. &c. By J. Frederic Daniell, Esq., For. Sec. R. S., Prof. Chem. in King's College, London

1842 ◽  
Vol 132 ◽  
pp. 137-155 ◽  
Keyword(s):  
Electromotive Force ◽  
Simple Expression ◽  
King's College ◽  
Royal Institution ◽  
The Subject ◽  
Michael Faraday

My dear Faraday, I Must beg permission to address you once more upon the subject of Voltaic Combinations. To this I am prompted by several considerations. In the first place, the beautiful law of Ohm, and the simple expression which he has given of the electromotive force and resistances of a voltaic circuit, enable me to review with advantage, and to correct, many of the conclusions which I had derived from former experiments; and have suggested additional experiments, the results of which will tend, I trust, to remove some obscurities and ambiguities which were left in my former communications.

scholarly journals Sixth letter on voltaic combinations, addressed to Michael Faraday, Esq., D. C. L., F. R. S., Fullerian Professor of Chemistry in the Royal Institution of Great Britain, &c., by John Frederic Daniell, Esq., Foreign Sec. R. S., Professor of Chemistry in King’s College, London

1843 ◽  
Vol 4 ◽  
pp. 384-384
Keyword(s):  
Great Britain ◽  
Electromotive Force ◽  
The Body ◽  
Theoretical Knowledge ◽  
King's College ◽  
The Arts ◽  
Royal Institution ◽  
The Law ◽  
Michael Faraday

The purport of this letter is to follow the consequences of the law of Ohm, and the expressions which result from it, relative to the electromotive force, and to the resistances in the course of a voltaic circuit; to apply this theory to the verification of the conclusions which the author had formerly deduced from his experiments; and to suggest additional experiments tending to remove some obsculities and ambiguities which existed in his former communications. In following out these principles, the author is led to offer various practical remarks on the different forms of voltaic batteries which have been proposed with a view either to the advancement of our theoretical knowledge of the science, or to the service of the arts. The author enters more particularly into an explanation of the principles on which the cylindric arrangement of the battery he has introduced is founded, which appear to him to have been greatly misunderstood. The formulæ and the calculations which form the body of this paper are not of a nature to admit of being reported in the present abstract.

scholarly journals II. On the supposed identity of biliverdin with chlorophyll, with remarks on the constitution of chlorophyll

1864 ◽  
Vol 13 ◽  
pp. 144-145 ◽  
Keyword(s):  
Relative Proportion ◽  
The Other ◽  
Land Plants ◽  
Blue Colour ◽  
Strong Fluorescence ◽  
Chemical Examination ◽  
Yellow Substance ◽  
Yellow Body ◽  
The Subject ◽  
Made In

I have lately been enabled to examine a specimen, prepared by Professor Harley, of the green substance obtained from the bile, which has been named biliverdin, and which was supposed by Berzelius to be identical with chlorophyll. The latter substance yields with alcohol, ether, chloro­form, &c., solutions which are characterized by a peculiar and highly di­stinctive system of bands of absorption, and by a strong fluorescence of a blood-red colour. In solutions of biliverdin these characters are wholly wanting . There is, indeed, a vague minimum of transparency in the red; but it is totally unlike the intensely sharp absorption-band of chlorophyll, nor are the other bands of chlorophyll seen in biliverdin. In fact, no one who is in the habit of using a prism could suppose for a moment that the two were identical; for an observation which can be made in a few seconds, which requires no apparatus beyond a small prism, to be used with the naked eye, and which as a matter of course would be made by any chemist work­ing at the subject, had the use of the prism made its way into the chemical world, is sufficient to show that chlorophyll and biliverdin are quite distinct. I may take this opportunity of mentioning that I have been for a good while engaged at intervals with an optico-chemical examination of chlorophyll. I find the chlorophyll of land-plants to be a mixture of four substances, two green and two yellow, all possessing highly distinctive optical properties. The green substances yield solutions exhibiting a strong red fluorescence; the yellow substances do not. The four substances are soluble in the same solvents, and three of them are extremely easily decomposed by acids or even acid salts, such as binoxalate of potash ; but by proper treat­ment each may be obtained in a state of very approximate isolation, so far at least as coloured substances are concerned. The phyllocyanine of Fremy is mainly the product of decomposition by acids of one of the green bodies, and is naturally a substance of a nearly neutral tint, showing however ex­tremely sharp bands of absorption in its neutral solutions, but dissolves in certain acids and acid solutions with a green or blue colour. Fremy’s phylloxanthine differs according to the mode of preparation. When pre­pared by removing the green bodies by hydrate of alumina and a little water, it is mainly one of the yellow bodies; but when prepared by hydro­chloric acid and ether, it is mainly a mixture of the same yellow body (partly, it may be, decomposed) with the product of decomposition by acids of the second green body. As the mode of preparation of phylloxantheine is rather hinted at than described, I can only conjecture what the sub­stance is ; but I suppose it to be a mixture of the second yellow substance with the products of decomposition of the other three bodies. Green sea­ weeds ( Chlorospermeæ ) agree with land-plants, except as to the relative proportion of the substances present; but in olive-coloured sea-weeds ( Melanospermeæ ) the second green substance is replaced by a third green sub­stance, and the first yellow substance by a third yellow substance, to the presence of which the dull colour of those plants is due. The red colouring-matter of the red sea-weeds ( Rhodospermeæ ), which the plants contain in addition to chlorophyll, is altogether different in its nature from chloro­phyll, as is already known, and would appear to be an albuminous substance. I hope, before long, to present to the Royal Society the details of these researches.

VII. On a group of varieties of the muscles of the human neck, shoulder, and chest, with their transitional forms and homologies in the mammalia

1870 ◽  
Vol 160 ◽  
pp. 83-116 ◽  
Keyword(s):  
Head And Neck ◽  
Royal Society ◽  
King's College ◽  
Extensive Range ◽  
Statistical Frequency ◽  
The Subject ◽  
Transitional Forms ◽  
Made In

In the 'Proceedings of the Royal Society,’ between the years 1864 and 1868 inclusive, were published five series of observations upon variations in Human Myology, made in the Anatomical Rooms of King’s College, London. These observations extended over 202 dissected subjects ; they were restricted chiefly to the muscles of the head and neck and those acting upon the extremities, and did not include the numerous irregularities which are usually found in those of the back. From the extensive range of the subject, and the importance of ascertaining as far as possible the statistical frequency of the abnormal forms, there was little opportunity afforded of giving due prominence to many of the specimens which were entitled to special distinction, either from their first appearance in the records of anatomical science, or from their homological importance as transitional forms, or as representatives of muscles hitherto found only in certain classes of animals.

scholarly journals X. Further observations on voltaic combinations. In a letter addressed to Michael Faraday, Esq. D. C. L. F. R. S., Fullerian Prof. Chem. Royal Institution, Corr. Memb. Royal & Imp. Acadd. of Sciences, Paris Petersburgh, &c

1837 ◽  
Vol 127 ◽  
pp. 141-160 ◽  
Keyword(s):  
Royal Society ◽  
Saturated Solution ◽  
Average Amount ◽  
Standard Acid ◽  
Royal Institution ◽  
The Subject ◽  
Principal Subject ◽  
Michael Faraday ◽  
Mixed Gases

My dear Faraday, I Had intended, ere this, to have addressed you upon the subject of the measure of affinity which the constant battery may be made to supply, as indicated by the con­cluding experiment of my last letter; but my attention has been diverted, and the whole of my leisure occupied by what I found to be a necessary preliminary investi­gation of the effects of changes of temperature upon the voltaic action. In the course of my experiments upon this principal subject, I have also been led to observe some curious disturbances and diversions of the battery current, from secondary combina­tions; and I now submit the results of the whole inquiry to your judgment, not without a hope that you may consider them of sufficient interest and importance to be communicated to the Royal Society. You may perhaps recollect that the standard charge, which I finally adopted in the use of the constant battery, was a mixture of eight parts of water with one of oil of vitriol on the side of the zinc, and a saturated solution of sulphate of copper in contact with the copper; and that the average amount of its work, as measured by the voltameter, was 11 cubic inches of mixed gases per five minutes. It occurred to me that the resistance to the current might again be reduced by dissolving the salt in the standard acid instead of water; and upon making the experiment I found the action increased from 11 cubic inches to 13 cubic inches, at which rate it steadily maintained itself; the following being the result of one series of observations.

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