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Chloride of Calcium (Purified Muriate of Lime), total insoluble impurities under per cent. CHLORIDE OF BARIUM (Muriate of Baryta), free from Iron and Lead, total impurities, water excepted, under per cent Silic GASKELL, DEACON, & CO., ALKALI MANUFACTURERS WIDNES, LANCASHIRE. ilicates of Soda and Potash in the state of Soluble glass, or in CONCENTRATED SOLUTION of first quality, suited for the manufacture of Soap and other purposes, supplied on best terms by W. GOSSAGE and Sons, Widnes Soapery, Warrington. London Agents, CLARKE and COSTE, 19 and 20, Water Lane, Tower Street, E.C., who hold stock ready for delivery. SCIENTIFIC PRESENTS.-Collections to Illustrate "Lyell's Elements of Geology," and facilitate the important study of Mineralogy and Geology, can be had at 2, 5, 10, 20, 50, to 500 guineas; also single specimens of Minerals, Rocks, Fossils and Recent Shells. Geological Maps, Hammers, all the recent publications, &c., of J. TENNANT, Mineralogist to Her Majesty, 149, Strand.-Private Instruction is given in Geology and Mineralogy by Mr. Tennant, F.R.G.S., at his residence, 149, Strand, W.C. PRACTICAL CHEMISTRY. Mr. Henry Matthews, F.C.S., is prepared to give Instruction in all branches of PRACTICAL CHEMISTRY, particularly in its application to MEDICINE, AGRICULTURE, and COMMERCE. The Laboratory is open daily, except Saturday, from ten t five o'clock; on Saturday, from ten till one o'clock. Mr. Matthews is also prepared to undertake ANALYSES of every description. For Particulars and Prospectuses, apply to Mr. Henry Matthews the Laboratory, 60, Gower Street, Bedford Square, W.C. THE CHEME LIBR NEWS. to 205° C. for twelve hours: a quantity of sulphurous acid was formed. (4). Two similar tubes, containing the same salt in "air," contained no sulphurous acid. (5). With dried ferrous sulphate, similarly treated, no sulphurous acid was produced at that temperature. I intend to pursue this subject further, and to investigate the effect of nascent hydrogen on sulphuric acid of various densities, at the temperatures of their boiling-points. VOL. XXVIIES/No. 71. 11-11 2012 JUL ON A CURIOUS REACTION OF BENZOIC, SALICYLIC, By T. L. PHIPSON, Ph.D., F.C.S. WHEN benzoic acid and glucose, in the proportions of about 3 equivs. of the former to 1 equiv. of the latter, are mixed with a large excess of monohydrated sulphuric acid, and the mixture is slightly warmed, a fine blood-red colour is developed, very similar to that produced when salicin or willow-bark are touched with concentrated sulphuric acid. After a while the mixture becomes brown, and then blackens. Benzoic acid alone does not produce this reaction. It matters little whether the glucose is artificial or natural. Salicylic acid, with glucose, treated in the same manner, presents the same reaction in a still more decided manner. Hippuric acid, with glucose and sulphuric acid, gives first a clear brown mixture, in which also the blood-red colour soon developes itself; then the whole mass becomes black, and evolves a large quantity of an odourless and colourless gas. This gas is not absorbed by water nor by potash, and is inflammable, burning with a blue flame: I conclude that it is chiefly oxide of carbon. As the reaction continues from this time, after the source of heat is withdrawn, the mixture soon becomes very hot, and then sulphurous acid is given off also. IN the course of the various controversies relating to the water process frequent mention has been made of the time required for the development of the Nessler colour. According to some experimenters, a few minutes suffice for the full colouration; according to others, half an hour or more is necessary. These differences have their origin in differences in the quality of the Nessler reagent. I have known two Nessler reagents which, although in the course of hours giving the same depths of colour with the same quantity of ammonia, required very different times for the production of the colouration. One sample of Nessler reagent gives its maximum of colour almost immediately, and another sample takes a quarter of an hour or an hour for full development. To a great extent, these differences depend upon whether or not a sufficient quantity of solution of corrosive sublimate has been added to the finished Nessler reagents PRELIMINARY NOTE ON THE REDUCTION OF whether it takes an hour, is a matter of vital importance Whether the Nesslerising takes a couple of minutes, or HYDROGEN. SULPHURIC ACID BY This will, I expect, afford an explanation of the fact that sulphuric acid, even containing a considerable proportion of water, yields, when heated to the boiling-point with zinc, not hydrogen, but sulphurous acid. In some measure to confirm this reaction, I heated (1) redistilled sulphuric acid in an atmosphere of hydrogen, in a sealed tube, for twelve hours, at a temperature of 205° C.: when broken, a quantity of sulphurous acid was found in the tube in the gaseous state. (2). Two similar tubes, containing the same acid in air, heated at the same time to 205° C., contained, when opened, no sulphurous acid. (3). A sealed tube, containing hydro-potassic sul NOTE ON THE NESSLER TEST. to those persons who are working the ammonia process of water analysis; and since the employment of the ammonia process has become almost universal, I have deemed it to be worth while to direct attention to the necessity of a careful preparation of the Nessler reagent. I have, moreover, made arrangements with Messrs. Townson and Mercer for the supply of quick Nessler reagent who do not feel disposed to take the trouble of making the at the rate of twenty shillings per litre. Those chemist. reagent themselves have now the opportunity of buying it Two papers on the above subject have recently appeared in the CHEMICAL NEWS, viz., one by Mr. T. L. Paterson (vol. xxvii., p. 111), and a short review of the same by Mr. A. S. Wilson (vol. xxvii., p. 225). A somewhat lengthy discussion on the same subject has also been carried on, in the pages of the "Greenock Sugar Trade Review," between Mr. Paterson and Mr. Murphy, of Liverpool, the practical results of which seem somewhat small when compared with the amount of noise made. Some of the statements made are, to say the least of it, rather novel; but it is a pity that a scientific discussion should be allowed to degenerate into mere personal wrangling, not to speak of doggerel rhymes. With the view of satisfying myself as to the accuracy of some of the points in dispute, I have recently made a considerable number of experiments. These have been more especially directed to the determination of the moisture in samples of new char, and the presence of organic matter soluble in water, glass tube of this form is useful, the thermometer being passed through a cork, but for higher temperatures a plain tube is to be preferred. A great number of experiments were made with this apparatus, in order to determine the water by direct weighing, some of the results of which are given below. Two grms. heated in the air-current Unground. Ground. In one of his replies to Mr. Paterson, Mr. Murphy through the lid. For temperatures not over 350° F. a makes the somewhat startling announcement that water with which new char has been treated is strongly alkaline, and will therefore dissolve appreciable quantities of organic matter from a paper filter. He thus accounts for the soluble organic matter found by Mr. Paterson in his experiments. I must confess that I, for one, have yet to learn that the water from new char is strongly alkaline, much more that it will dissolve filter-paper. In order to set aside all doubt on the subject, however, the following experiment was made:-5 grms. of a sample of new char were treated with water, and the liquid filtered without the use of paper, the neck of the funnel being stopped with recently ignited asbestos. The filtrate, which was quite colourless, and only very feebly alkaline, was carefully evaporated to dryness in a weighed platinum basin; the residue dried at 130° C., weighed, and cautiously ig. nited. The contents of the basin blackened quite percep. tibly; and on the ignition being completed, and the capsule weighed, the loss was found to be 0.112 per cent a result corresponding very closely with that given by Mr. Paterson in his paper. Although the moisture in samples of old or used char can be correctly determined at 212° F., it is well known that this temperature is quite inadequate for the expulsion of the whole of the water from new char. In his instructions for the analysis of bone-black, Fresenius gives 160° C., to 180° C. (320° F. to 356° F.) as the temperature at which the moisture should be estimated. A few years ago Dr. Wallace, in a paper on "Animal Charcoal," gave it as his opinion that a temperature of not less than 350° F. was necessary. Mr. Paterson, however, considers 350° F. much too high, and sufficient to destroy a portion of the organic matter. He considers that five hours in the water-bath at 212° F. is all that is necessary, and asserts that char, during the process of pounding, always loses water. Now, while it is quite possible that long-continued grinding in a warm atmosphere may have that effect, it is difficult to understand how a porous substance like charcoal, which retains water somewhat persistently, should lose some of it, during the short time necessary for reducing it to powder. On the contrary, we should rather expect a slight increase. That this is really the case, the results of Mr. Wilson's experiments, as well as my own, seem to demonstrate. The following experiments were made with reference to this part of the subject: A.-(1). A sample of new char was taken, and one-half reduced to powder; both were placed in tightly-corked bottles: 2 grms. of each were weighed out and kept in the water-bath, under precisely similar conditions. The loss of weight was as follows: ΙΟ 7'07 At 350° F. for 15 minutes gave 6.50 per cent. 6.52 percent. In 1 hour I 3'23 per cent. 3'29 35 5 39 At 450° F. for 20 minutes gave 5.24 per cent. ", 500° 15 m. longer,, 5:29 Two grms. were taken as before, but in this case the loss of weight was also found by weighing the residue in the boat, which was placed in a closed tube. At 500° F. for 10 min. ", 500° 20 5 m. longer 5.65 At 500° F. for 20 min. 5*35 6.03 At 350° F. for 15 minutes the loss was 6'11 per cent. 10 m. longer " 400° 450° 11 500° (3). 2 grms. of the sample were placed in a platinumboat, and introduced into a glass tube about 9 inches long. The tube was then placed in an air-bath, made for the purpose, and one end attached to an apparatus for drying the air previous to entering the tube. To the other end a weighed chloride of calcium tube was attached, and this again was placed in communication with one arm of a Staedler's aspirator, by means of which a uniform and well-regulated current of dry air could always be obtained. The air-bath was heated by a small Bunsen, the temperature being registered by a thermometer passed justified in concluding 1. That the water in a sample of new char is sensibly increased by the process of pounding, instead of being diminished. 2. That a temperature of 212° F. is quite inadequate for the determination of the water in such samples. 3. That there is a loss on heating in the air-bath up to 500° F., and that, if heated in the air-current, there is a gain in the CaCl2 tube up to that temperature, showing that even at 350° F. the water is not completely expelled. The determination of the water by direct weighing is, of course, to be preferred to the ordinary air-bath, which at the higher temperatures usually gives too high results. The difference between the gain in the CaCl2 tube and the loss from the residual char shows that the loss of weight is not entirely water. I would recommend heating in the air-current for, say, 30 minutes, as giving reliable results. Chemical Laboratory, 107, Bath Street, Glasgow. ON THE ACTION OF WATER ON LEAD. By Sir ROBERT CHRISTISON, Bart. THE most general results of the author's former inquiries are-1. That the purest waters act the most powerfully on lead, corroding it, and forming a carbonate of peculiar and uniform composition. 2. That all salts impede this action, and may prevent it altogether, some of them when in extremely minute proportions. 3. That the proportion of each salt required to prevent action is nearly in the inverse ratio of the solubility of the compound which its acid forms with the oxide of lead. The effect of certain inorganic and organic ingredients of water in modifying the preservative power of the salts the author did not investigate. This has been made the subject of numerous inquiries and observations by others, chiefly, however, of a desultory nature, some of them much too succinctly described, and some, also, of questionable accuracy. bonate in natural waters, the practical importance of the fact is inconsiderable. The corrosive action of water upon lead has often been confounded with other causes of corrosion, and the water has borne the blame. Thus the true action has been confounded with the corrosive action of potent agents accidentally coming in contact with the metal in the presence of water, as, for example, when a lead pipe has been led through fresh mortar, which is frequently or permanently kept moist, or when lumps of fresh mortar have been allowed to fall upon the bottom of a lead cistern. The true or simple action of water has not unfrequently been confounded also with the effects of galvanic action. Thus, if a lead pipe or cistern be soldered with pewter solder and not with lead, erosion takes place near the line of junction of the solder with the lead. The presence of bars of other metals crossing lead, or bits of them lying on it, will also develop the same action; and some facts seem to point to the same property being possessed in a minor degree by some stony and earthy substances. This observation may explain the local erosion sometimes observed in cisterns containing hard water; since, if galvanic action be excited, it will be increased by the fact of saline matter existing more largely in these waters than in soft or comparatively pure water. ་་་ Lastly, some observers have contradicted former statements, because under certain circumstances, which led them to anticipate no action, they nevertheless found lead in water, but only in extremely minute and unimportant proportion. The test for lead, hydrosulphuric acid, when employed in the way now usually practised is so delicate as to detect that metal when dissolved in ten million parts of water, or even more. Facts, however, warrant the conclusion that the impregnation must amount to at least ten times this quantity before water can act injuriously on man, however long it may be used.-Iron. It has been denied that water acts by reason and in the ratio of its purity; and it has even been alleged that distilled water itself does not act if really quite pure. The author has, however, invariably found the reverse to be the case, and can assign no other explanation of these statements, except some error in manipulation. For example, a very pure spring water was sent to him from the south of England, with the assurance that it had been found incapable of attacking lead; but, on making trial of it, he found it to act with an energy not inferior to that MEASUREMENT AND UTILISATION OF THEM.* of distilled water. It has also been stated that ordinary distilled water is apt to contain a trace of nitric or nitrous acid, from nitrates incidentally present in the water subjected to distillation; and that such water, if distilled after the addition of a little potash to fix the acid thoroughly, yields a distillate which has no action upon lead. But when the author prepared distilled water in this way, with great care to prevent the access of impurities from other sources, the only result was that the action was even stronger than that of the ordinary distilled water of the laboratory, and greater, indeed, than he had ever before observed. An interesting statement has been made by Dr. Nevins, to the effect that some salts appear to allow of a certain action going on when they are present in water largely, although their influence when they exist in very small quantities is to act as preventives. This result the author has sometimes obtained, and has found the action such as might prove dangerous. But its limit requires to be defined; and there is reason to suppose that the proportion required to permit action will be found to be greater than is ever likely to occur in the instance of waters applicable to household use. It has also been said, but in general terms and without experimental proof, that the presence of carbonate of soda, even in a hard water, takes away the preventive influence of the other salts, and enables the water to dissolve lead. There appears to be some foundation for this statement; but here, too, it is necessary to fix what is the limit to such influence before its importance can be valued. Moreover, as bicarbonate of soda appears to have no such effect, and this is the usual form of the car ON THE ENERGIES OF THE IMPONDERABLES, WITH ESPECIAL REFERENCE TO THE By the Rev. ARTHUR RIGG, M.A. (Continued from p. 7). MEN need but watch the progress of science-truths for a few years, or read the development, stage by stage, of any branch of investigation, to be satisfied of this, that, with whatever pertinacity and show of reasoning any theory is propounded and established, it rapidly wanes. Astronomical and geological truths and facts, how often and again have they been satisfactorily (?) explained, and yet how soon and how rapidly has one explanation been so crushed out by another, that the first, which by its authors was applauded, is by the upholders of the second ridiculed. The theories of the imponderables, with which we must occasionally deal or allude to, but with which we are in no degree further concerned, are, day by day, in a transition state. Like the cause of solar heat, or the rotation of the moon, they are a bloodless battle-field, on which, with our increasing love of talking and our decreasing love of working, words may war with words. A triumphant victory to-day in science theory may be the prelude to an ignominious defeat of the same theory to-morrow. Subject, doubtless, to many dissentient views, the belief that he who propounds theory, and uses theories solely as means or ways by which to convey ideas of how such and such facts may perhaps be brought about, and not as expressing a conviction that the way described is the actual plan in operation, he is the truly wise man. Those who allow themselves to dwell upon the conception * The Cantor Lectures, delivered before the Society of Arts. and the development of theories, who build theory upon theory, who sometimes pile Ossa upon Pelion, and sometimes Pelion upon Ossa, are not unlike those whom Milton describes"Who reasoned high Of providence, foreknowledge, will, and fate, Fixed fate, free will, foreknowledge absolute, And found no end, in wandering mazes lost." Thus it is that the decisions of one age and one day differ from those of another age and another day. Theories, we must remember, are but opinions; with opinions, as such, this course of lectures is not concerned. The facts of Nature, so far as they have yet been made apparent, or may be in process of being so, are our province. They change not. To those who have appealed to Nature direct, and brought from her exhaustless stores of knowledge some truths that men may utilise, is due the information which is to be brought before you. The mode by which they have won this knowledge is exactly that pursued in our courts of law and equity, to arrive at the truth on one point, and on one point only. Look how long and tedious legal investigations seem, and yet in how few words the result is declared. Guilty or not guilty-Verdict for the plaintiff or verdict for the defendant. One or other of these very brief phrases records the conclusion or the judgment of many days of patient labours and searchings for truths. To not less careful questioning by men in years past, as well as now current, we owe all we know of the energies, the measurement and utilisation of which is to be a feature in these lectures. That cross-questioning of the keenest and clearest kind has been essential may be inferred from the fact that these energies are so co-related -so mutually convertible-that they merge and change, Protean-like, one into the other so instaneously that no one energy can be conveniently retained alone and in operation. They thus pass and interchange without (to our eyes) a signal from any magician's wand. The transmutations of the imponderables are accomplished in a way that would have gladdened the eyes of the most profound alchemist, could he have seen as great transmutations in some of the material things in which he worked. For example, whenever energy is lost by resistance, heat is produced, i.e., when the resistance is perfect and complete, admitting of no intermediate state; e.g., if a wheel in machinery does not move easily, the consequence is heat, manifested on the shaft. If, however, that energy can be converted into an intermediate state, then this state may be assumed-much as light from gas is an intermediate state between chemical affinity and heat. Do what we may, that from which energy results can neither be created nor destroyed. In the case of blows by impact, as in the tongue of a bell, or the hammer on an anvil, or a clock, or a piano, or on a drum-head, or on a gong, then, whilst doubtless some part of this checked energy is converted into heat, yet a large portion is spent in the production of vibrations in matter, appreciable to our senses, and suggestive of vibrations in molecules, which our senses, aided by physical appliances, have not yet made visible, but which chemical changes, and what to the minds of science theorists of the present day is conclusive evidence, seem to point as similar vibrations in the invisible molecules and atoms of which it is assumed that bodies consist. These remarks may suffice to explain that whilst to speak of estimating an "energy" is easy, yet to estimate that "energy" is an employment which tasks the keenest and most watchful faculties of the human mind, as well as claiming from human hands the production of some of their most exquisite and refined work. The difficulty of the task results not so much from a solution of the simple problem which the words "estimate that energy' convey, as from the incompetence alluded to of isolating and continuing the special energy and noting its operation. For no one of nature's energies, 35 be they ponderable or imponderable, is alone. Solitariness in the unseen, as well as in the seen, is no part of nature's plans. Faraday seemed to have realised this view in great intensity when he wrote-"If, as I believe, dualities are essential to the forces, are always equal, are mutually dependent, that one cannot appear or exist without the other the proof of this would lead to many consequences of high importance to the philosophy of force generally."* This interlacing of energies,—this co-relation, as it is called, of physical forces,-whilst it knits in harmonious union energies which are nominally distinct, baffles the investigator who wishes to assign to each its share in any specific work. For example, the energy of gravity operates everywhere, and our fundamental principle in hydraulics, that fluids press equally in all directions, may be granted as a postulate. The experiments by which it can be confirmed may be and is very clearly described, but no one has ever made or can make them. Gravity never ceases to impress upon fluids a downward tendency, and so prevents an equality of pressures in all directions being established. It may be in the interest of the Moslem faith to assert that, without visible means, Mahomet's coffin rests between earth and heaven; but, assuming the truth of the tradition, or of the fact (whichever it be), we know well that gravity operates in all its wonted intensity, and that the coffin is held there (if held at all) by the introduction of some counteracting energy, as that of mag. netism. The energy of electricity is ever passing into heatthat of heat into electricity or light. Electricity, again, appears to assume the form of vitality; and then, again, it totally fails to fulfil the vital conditions. In some animals the exhaustion of their muscular energy is con sequent upon the exhaustion of their vital energy, and no electrical appliance can restore the vital energy, even though it seems to restore the muscular. Take affinity. This passes, by means unknown to us, into electricity and heat. There is also this peculiarity amongst these energies. The work of one energy, estimated by any means known to us, gives no indication of the work of some other energy, resident or potential, in the same matter. For example, the estimation of a drop of water by gravity standards-to speak of it as weighing so many grains gives no indication whatever of its ability to promote affinities, to absorb and convey heat, to decom. pose light. And if even all these were known, there would still be no indication that upon an electrical standard of measurement its destructive effects are equal to that of a flash of lightning. The only energies that may be said to be non-interchangeable are those of gravity and vitality. The former is enduring, the latter fleeting. The character of the one is persistence and constancy; that of the other, change and variety. Gravity may be said to be quietly resident in matter; vitality shows its presence by growth or motion. Gravity is an energy pervading all nature, as intense in grains of sand as in the mountain; in a drop of water as in the river or the ocean. Disregarding alike the vitality of the plant or the animal-for gravity treats them as though they were as inert, indifferent, and unconscious of its presence as the soil of the garden, or the mineral under the earth-thus this energy, which is to occupy our chief consideration in the next lecture, is alone, and yet we shall find how that it has been left for recent times to tabulate its measure, to report and utilise, under the guidance of ordinary arithmetical and mathematical rules, the scientific and social consequences of the measure so established. The other energy, that of vitality, which is to occupy *Proc. Roy. Inst. for 1854, 6. |