On the action of the rays of the solar spectrum on vegetable colours

1843 ◽  
Vol 4 ◽  
pp. 393-394
Keyword(s):  
Royal Society ◽  
Chemical Change ◽  
Solar Spectrum ◽  
Heating Power ◽  
The Other ◽  
Solar Light ◽  
Equal Degree ◽  
Viola Tricolor ◽  
Degree Of Condensation ◽  
The One

The author, having prosecuted the inquiry, the first steps of which he communicated in a paper read to the Royal Society in February 1840, relating to the effects of the solar spectrum on the colouring matter of the Viola tricolor , and on the resin of guaiacum, relates, in the present paper, the results of an extensive series of similar experiments, both on those substances, and also on a great number of vegetable colours, derived from the petals of flowers, and the leaves of various plants. In the case of the destruction of colour of the preparations of guaiacum, which takes place by the action of heat, as well as by the more refrangible rays of light, he ascertained that although the non-luminous thermic rays produce an effect, in as far as they communicate heat, they are yet incapable of effecting that peculiar chemical change which other rays, much less copiously endowed with heating power, produce in the same experiment. He also found that the discoloration produced by the less refrangible rays is much accelerated by the application of artificial terrestrial heat, whether communicated by conduction or by radiation; while, on the other hand, it is in no degree promoted by the purely thermic rays beyond the spectrum, acting under precisely similar circumstances, and in an equal degree of condensation. The author proceeds to describe, in great detail, the photographic effects produced on papers coloured by various vegetable juices, and afterwards washed with solutions of particular salts; and gives a minute account of the manipulations he employed for the purpose of imparting to paper the greatest degree of sensitiveness to the action of solar light. This action he found to be exceedingly various, both as regards its total intensity and the distribution of the active rays over the spectrum. He observed, however, that the following peculiarities obtain almost universally in the species of action exerted. First, the action is positive ; that is to say, light destroys colour, either totally, or leaving a residual tint, on which it has no further, or a very much slower action; thus effecting a sort of chromatic analysis, in which two distinct elements of colour are separated, by destroying the one and leaving the other outstanding. The older the paper, or the tincture with which it is stained, the greater is the amount of this residual tint.

scholarly journals Description of a new barometer, recently fixed up in the apart­ments of the Royal Society; with remarks on the mode hitherto pursued at various periods, and an account of that which is now adopted, for correcting the observed height of the mercury in the society’s barometer

1843 ◽  
Vol 4 ◽  
pp. 1-3
Keyword(s):  
Royal Society ◽  
The Other ◽  
Chemical Effect ◽  
The Absolute ◽  
The One ◽  
And Control ◽  
Usual Scale

The barometer, here alluded to, may in some measure be consi­dered as two separate and independent barometers, inasmuch as it is formed of two distinct tubes dipping into one and the same cistern of mercury. One of these tubes is made of flint glass, and the other of crown glass, with a view to ascertain whether, at the end of any given period, the one may have had any greater chemical effect on the mercury than the other, and thus affected the results. A brass rod, to which the scale is attached, passes through the framework, between the two tubes, and is thus common to both : one end of which is furnished with a fine agate point, which, by means of a rack and pinion moving the whole rod, may be brought just to touch the surface of the mercury in the cistern, the slightest contact with which is immediately discernible; and the other end of which bears the usual scale of inches, tenths, &c.; and there is a separate vernier for each tube. A small thermometer, the bulb of which dips into the mercury in the cistern, is inserted at the bottom : and an eye­piece is also there fixed, so that the agate point can be viewed with more distinctness and accuracy. The whole instrument is made to turn round in azimuth, in order to verify the perpendicularity of the tubes and the scale. It is evident that there are many advantages attending this mode of construction, which are not to be found in the barometers as usu­ally formed for general use in this country. The absolute heights are more correctly and more satisfactorily determined ; and the per­manency of true action is more effectually noticed and secured. For, every part is under the inspection and control of the observer; and any derangement or imperfection in either of the tubes is imme­diately detected on comparison with the other. And, considering the care that has been taken in filling the tubes, and setting off the scale, it may justly be considered as a standard barometer . The pre­sent volume of the Philosophical Transactions will contain the first register of the observations that have been made with this instru­ment.

scholarly journals On some circumstances relating to the economy of bees

1833 ◽  
Vol 2 ◽  
pp. 346-347
Keyword(s):  
Royal Society ◽  
The State ◽  
The Other ◽  
Compact Mass ◽  
Whole Number ◽  
Permanent Settlement ◽  
The One ◽  
Hollow Tree ◽  
As If

The author had already stated, in a former communication to the Royal Society, his having noticed that for several days previous to the settling of a swarm of bees in the cavity of a hollow tree adapted to their reception, a considerable number of these insects were incessantly employed in examining the state of the tree, and particularly of every dead knot above the cavity which appeared likely to admit water. He has since had an opportunity of observing that the bees who performed this task of inspection, instead of being the same individuals as he had formerly supposed, were in fact a continual succession of different bees; the whole number in the course of three days being such as to warrant the inference that not a single labouring bee ever emigrates in a swarm without having seen its proposed future habitation. He finds that the same applies not only to the place of permanent settlement, but also to that where the bees rest temporarily, soon after swarming, in order to collect their numbers. The swarms, which were the subjects of Mr. Knight’s experiments, showed a remarkable disposition to unite under the same queen. On one occasion a swarm, which had arisen from one of his hives, settled upon a bush at a distance of about twenty-five yards; but instead of collecting together into a compact mass, as they usually do, they remained thinly dispersed for nearly half an hour; after which, as if tired of waiting, they singly, one after the other, and not in obedience to any signal, arose and returned home. The next morning a swarm issued from a neighbouring hive, and proceeded to the same bush upon which the other bees had settled on the preceding day; collecting themselves into a mass, as they usually do when their queen is present. In a few minutes afterwards a very large assemblage of bees rushed from the hive from which the former swarm had issued, and proceeded directly to the one which had just settled, and instantly united with them. The author is led from these and other facts to conclude that such unions of swarms are generally, if not always, the result of previous concert and arrangement.

XXIV.—On the Temperature Coefficient of Concentration Cells, in which the same salt is dissolved in two different solvents

1912 ◽  
Vol 31 ◽  
pp. 375-396
Author(s):  
A. P. Laurie
Keyword(s):  
Temperature Coefficient ◽  
Potassium Iodide ◽  
Royal Society ◽  
Platinum Electrode ◽  
The Other ◽  
Absolute Alcohol ◽  
Concentration Cell ◽  
New Type ◽  
The One ◽  
Concentration Cells

In a paper read before the Royal Society of Edinburgh (Proc. Roy. Soc. Edin., xxviii., part v., p. 382 (1908); Zeit. phys. Chem., lxiv. 5) I described a new type of concentration cell, in which the one platinum electrode was surrounded by a solution of ·025 molecules of KI containing ·001 molecules of iodine dissolved in absolute alcohol, and the other electrode was surrounded by ·025 molecules of KI and ·001 molecules of iodine, dissolved in water. This cell developed a considerable E.M.F. of ·198 volts at 25° C. in the direction which would transfer the iodine from water to alcohol and potassium iodide from alcohol to water.

scholarly journals VII.—On the Motion of a Heavy Body along the Circumference of a Circle

1865 ◽  
Vol 24 (1) ◽  
pp. 59-71
Author(s):  
Edward Sang
Keyword(s):  
Royal Society ◽  
Elliptic Functions ◽  
The Other ◽  
Philosophical Magazine ◽  
Circular Arc ◽  
Heavy Body ◽  
Great Ease ◽  
Fourth Volume ◽  
The Common ◽  
The One

In the year 1861 I laid before the Royal Society of Edinburgh a theorem concerning the time of descent in a circular arc, by help of which that time can be computed with great ease and rapidity. A concise statement of it is printed in the fourth volume of the Society's Proceedings at page 419.The theorem in question was arrived at by the comparison of two formulæ, the one being the common series and the other an expression given in the “Edinburgh Philosophical Magazine” for November 1828, by a writer under the signature J. W. L. Each of these series is reached by a long train of transformations, developments, and integrations, which require great familiarity with the most advanced branches of the infinitesimal calculus; yet the theorem which results from their comparison has an aspect of extreme simplicity, and seems as if surely it might be attained to by a much shorter and less rugged road. For that reason I did not, at the time, give an account of the manner in which it was arrived at, intending to seek out a better proof. On comparing it with what is known in the theory of elliptic functions, its resemblance to the beautiful theorem of Halle became obvious; but then the coefficients in Halle's formulæ are necessarily less than unit, whereas for this theorem they are required to be greater than unit.

The Reactions of Aniline and Its Homologs as Accelerators of Vulcanization

1928 ◽  
Vol 1 (2) ◽  
pp. 307-340
Author(s):  
Takeo Kimishima
Keyword(s):  
Reaction Mechanism ◽  
Chemical Reaction ◽  
Satisfactory Result ◽  
Chemical Change ◽  
The Other ◽  
Chemical Effect ◽  
Reaction Products ◽  
Thermal Change ◽  
Points Of View ◽  
The One

Abstract The accelerating action of aniline and its homologs can be considered from two points of view. The one is whether there are exothermic phenomena caused by the accelerators and the effect of those phenomena upon vulcanization. The other is the chemical effect upon vulcanization caused by reaction products derived as a result of chemical reaction of an accelerator and sulfur. In other words, the object of consideration in the former is the effect of thermal change, while that in the latter is the effect caused by chemical change. Leaving the former for later discussion, the writer will first describe the result of his experiments concerning the reaction products of accelerators and sulfur and the effect of these products upon vulcanization. In an investigation of this kind it is extremely difficult to extract and determine the effective elements from material derived from an accelerator in the process of vulcanizing reactions of rubber. No case has yet been known where a satisfactory result was realized by such a method. Therefore, the writer has first taken up the investigations of reactions of an accelerator with sulfur and by separating and refining each of the various reaction products approached the matter of vulcanization itself, and under various conditions caused these reaction products to act upon rubber. Thus the writer has followed the plan of establishing the reaction mechanism of accelerators by seeing the changes, both chemical and physical, together with their effect upon vulcanization.

scholarly journals Note on Dr. Burdon Sanderson’s latest views of ferments and germs

1878 ◽  
Vol 26 (179-184) ◽  
pp. 353-356
Keyword(s):  
High Temperature ◽  
Bacillus Anthracis ◽  
Royal Society ◽  
The Other ◽  
Spontaneous Generation ◽  
Outer Line ◽  
Living Things ◽  
Characteristic Behaviour ◽  
The Difference ◽  
The One

While writing the paper which the Council of the Royal Society has recently done me the honour of accepting for the Philosophical Transactions, the abstract of a lecture delivered by Dr. Burdon Sanderson to the association of Medical Officers of Health was placed in my hands. The teem in which the author’s name is justly held will certainly give eight and currency to the views enunciated in this lecture. Speaking: ferments Dr. Sanderson says :—“ In defining the nature of fermentition we are in a dilemma, out of which there is no escape except by compromise. A. ferment is not an organism, because it has no structure. It is not a chemical body, because when it acts upon other bodies it maintains its own molecular integrity. On the whole, it resembles an organism such more than it resembles a chemical body, for its characteristic behaviour is such as, if it had a structure, would prove it to be living. Ten years ago the opponents of spontaneous generation were called Pansperusts, because it was supposed that in the so-called generation equivoca, in very case in which Bacteria appeared to spring out of nothing, the result as referable to the influence of unseen but actually existing germs. The assearches of the last few years have carried us beyond this stage. . . . the outer line of defence, represented by the aphoristic expression omne ivum ex ovo , has been for some time abandoned. The ground which the orthodox biologist holds now, as against the heterodox, is not that every bacterium must have been born of another Bacterium, but that every Bacterium must have been born of something which emanated from another bacterium, that something not being assumed to be endowed with structure in the morphological or anatomical sense, but only in the molecular chemical sense. It is admitted by all, even by Professor Tyndall, that, far as structure is concerned, the germinal or life-producing matter out which Bacteria originate exhibits no characters which, can be appreciated by the microscope; and other researches have proved that the Seminal matter is capable of resisting destructive influences, particularly those of high temperature, which are absolutely fatal to the Bacteria themselves. Germs have given place to things which are ultramicr scopical—to molecular aggregates—of which all we can say is, what we have already said about the ferments, that they occupy the border between living and non-living things.” As directed against “ germs ” the argument that the “ germinal matter is capable of resisting destructive influences which are fatal to the themselves, will, I think, be found on consideration to lack validity Nobody is better acquainted than Dr. Sanderson with the two forms under which the contagium of splenic fever appears. He knows that the one fugitive and readily destroyed, the other persistent and destroyed will difficulty. Now the recent researches of Koch, which have been verified by Cohn, prove conclusively that the difference here referred to is bast upon the fact that the fugitive contagium is the developed organism Bacillus anthracis, while the persistent contagium is the spore of tin organism. Dallinger’s excellent observations also establish a difference between the death-temperatures of monad germs and of adult monads while I need not do more than refer to the forthcoming Part of till Philosophical Transactions for illustrations of the extraordinary differences of the same nature which my recent researches have brought to light.

III. On the causes of the great variation among the different measures of the Earth’s mean density

1857 ◽  
Vol 8 ◽  
pp. 295-299 ◽  
Keyword(s):  
Royal Society ◽  
The Other ◽  
The One ◽  
Limits Of Error

The result of the Pendulum experiments in the Harton Colliery, undertaken by the Astronomer Royal in 1854, and detailed in his paper presented to the Royal Society in January 1856, appears at first sight rather startling, as adding to the already somewhat discrepant measures or estimates of the earth’s mean density one more discordant than ever ; so that we have now values ranging from 4.7 to nearly 6.6; a range, which, in the absence of any sufficient ground for selecting any one as true to the exclusion of the rest, would seem to deprive us of all confidence in their correctness as measures , and leave them rather to be classed as estimates of a very rough description. But it will be my endeavour to show, that, while none of the methods employed are capable of giving strictly accurate results, the Cavendish experiment is the one which may be relied on as giving a good approximation to the truth, within limits of error (when conducted with proper precaution) far less than those to which either of the other methods are liable.

scholarly journals VII. Experimental researches in electricity.-Twenty-third Series

1850 ◽  
Vol 140 ◽  
pp. 171-188 ◽  
Keyword(s):  
Magnetic Field ◽  
Mode Of Action ◽  
Royal Society ◽  
The Other ◽  
Experimental Proof ◽  
Philosophical Paper ◽  
Iron Nickel ◽  
The One ◽  
Experimental Researches ◽  
The Magnetic Field

Four years ago I suggested that all the phenomena presented by diamagnetic bodies, when subjected to the forces in the magnetic field, might be accounted for by assuming that they then possessed a polarity the same in kind as, but the reverse in direction of, that acquired by iron, nickel and ordinary magnetic bodies under the same circumstances (2429. 2430.). This view was received so favourably by Plücker, Reich and others, and above all by W. Weber, that I had great hopes it would be confirmed; and though certain experiments of my own (2497.) did not increase that hope, still my desire and expectation were in that direction. Whether bismuth, copper, phosphorus, &c., when in the magnetic field, are polar or not, is however an exceedingly important question; and very essential and great differences, in the mode of action of these bodies under the one view or the other, must be conceived to exist. I found that in every endeavour to proceed by induction of experiment from that which is known in this department of science to the unknown, so much uncertainty, hesitation and discomfort arose from the unsettled state of my mind on this point, that I determined, if possible, to arrive at some experimental proof either one way or the other. This was the more needful, because of the conclusion in the affirmative to which Weber had come in his very philosophical paper; and so important do I think it for the progress of science, that, in those imperfectly developed regions of knowledge, which form its boundaries, our conclusions and deductions should not go far beyond, or at all events not aside from the results of experiment (except as suppositions), that I do not hesitate to lay my present labours, though they arrive at a negative result, before the Royal Society.

scholarly journals The homogeneous catalysis of gaseous reactions by iodine. The decomposition of propionic aldehyde, and a general discussion

1933 ◽  
Vol 142 (846) ◽  
pp. 77-88 ◽  
Keyword(s):  
Kinetic Analysis ◽  
Homogeneous Catalysis ◽  
Chemical Change ◽  
Point Of View ◽  
The Other ◽  
Side Reactions ◽  
General Point ◽  
Chemical Changes ◽  
Secondary Reactions ◽  
The One

Previous papers have dealt with the homogeneous catalysis of the decomposition of ethers and of acetaldehyde by iodine. The problem of the mechanism of these catalysed reactions can be approached in two ways: on the one hand, by seeking to obtain as complete a picture as possible of the types of chemical change which are susceptible to the action of a given catalyst, and, the catalysts which will promote a given chemical change; and, on the other hand, by investigating in detail the kinetics and molecular statistics of individual reactions. Experiments on the different kinds of reaction which iodine will catalyse are being published elsewhere. Most of the chemical changes have involved too many side reactions, or secondary reactions with the catalyst, to be suitable for complete kinetic analysis. Nevertheless, they show the chemical specificity of the action of iodine in the clearest manner, and this aspect of the problem is discussed from a general point of view in the last section of the present paper.

scholarly journals XXXIII. A supplement to two papers published in the Transactions of the Royal Society, "On the science connected with human mortality;" the one published in 1820, and the other in 1825

1862 ◽  
Vol 152 ◽  
pp. 511-559 ◽  
Keyword(s):  
Royal Society ◽  
The Other ◽  
General Interest ◽  
Proper Solution ◽  
John Irving ◽  
Knowing That ◽  
The Subject ◽  
The One ◽  
Life Annuities ◽  
Three Lives

In offering to the Royal Society the ensuing Supplement to my two former papers on the Law of Mortality, with subsequent remarks on invalidism, I am anxious to acknowledge that I have derived great advantage from the encouragement and persuasion of my esteemed brother-in-law, Sir Moses Montefiore, Bart., given me to endeavour to com­pile and publish some of my later observations on the subject; knowing that, though I felt flattered by the attention originally shown by scientific gentlemen to these papers, they appeared to me capable of advantageous illustrations. Therefore I may venture to hope that if this Supplement merit the attention of those interested in this branch of science, I may consider that he has added a mite further to entitle him to the good wishes of those who applaud him for his constant endeavours to promote the general interest of mankind—endeavours which he has shown to extend through Europe and Asia in the cause of humanity, and to be exercised at home in various ways, among which I notice his attention to the practice of Life, Fire, and Marine Assurance; he being the President of the Alliance British and Foreign Life and Fire Assurance Com­pany; of which I was the founding Actuary, and in which Institution, though retired from it, I feel greatly interested; it having been established about the year 1824 by the late N. M. de Rothschild, Esq., the late John Irving, Esq., the late Samuel Gurney, Esq., and Francis Baring, Esq., and himself conjointly with other gentlemen, and he being also President of the Alliance Marine Assurance Society, founded at the same time by them with him. Art. 1. In the year 1820 the Royal Society did me the honour to publish in their Transactions a paper of mine on the Analysis and Notation applicable to the valuation of Life Contingencies, in which I introduced a new and general notation, which appealed to me far more extensively useful, and more explanatory of its object, than any other notation I had met with; and in that paper I think I introduced a new manner of deal­ing with the subject, by offering an analysis, with examples of the extensive use of it, applicable to some of the most intricate questions which had up to that period met with anything like a proper solution; and showed, by selections from the treatise of Life Annuities of my late learned and much-respected friend, Francis Baily, Esq., a mode of solution of all the problems in chapter 8 of that work, depending on a particular order of survivorship; problems previously considered many years before, and presented by my late friend William Morgan, Esq., of the Equitable Society, to the Royal Society, and published in their valuable Transactions; and which had been since considered, in a learned work on Life Annuities, by my late respected friend Joshua Milne, Esq., with some ingenious notation with respect to those contingencies. But still, the solutions given to many of the problems, though there were but three lives con­cerned, were of such an intricate practical form, as to be in my opinion perfectly useless; especially on considering that it was necessary to obtain, by Tables of single and joint lives, by necessary interpolations, the required data; as the differences to be used for the interpolations, in consequence of the great irregularity of the numbers of those Tables, are so irregular as to throw great doubt on the necessary accuracy of the results. And I think the examples I gave of my method could leave no doubt as to the comparative simplicity which resulted from it, and consequently comparative utility of my analysis; an analysis which applies where there are more than three lives concerned, and, in fact, where there are any number of lives to be considered. And I may refer the reader to my solutions in that tract, to enable him to make the com­parison.

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