and which give actual measure (sine or tangent galvanometers giving absolute measure). 1st. Let A put on a current through his galvanometer to the cable, and let B connect the cable through his galvanometer to the 2nd. Note the current e entering at A and the current e' received at B 3rd. Put on a battery at B and take away that from A, and now and that received at A=f 4th. Call the resistance of the conductor from A to the fault 5th. From the fault to the end of the cable 6th. Call the difference between e-e' =e =e' In both of these cases, when the resistance of the fault is considerable, it is often difficult to obtain accurate results, as the fault's resistance varies considerably at times, especially if the current used be positive (+). But when there are two or more wires between the stations in question, the fol lowing method removes all difficulty, and gives very accurate results. The Case 3.-At the distant station B have the defective wire connected to a good one, forming a loop from A to B and back again to A. Connect now the positive pole of a battery to the earth, and the negative pole to the differential galvanometer. Connect the one wire of the differential galvanometer to the good conductor, and the other wire through the resistance coils (rheostat) to the defective wire. current from the battery will now split one portion of the current going through the good wire to the fault, the other portion going through the resistance coils to the faulty cable, and then to the fault where current escapes to the earth. Introduce now so much resistance as shall make the two channels equal. Call this resistance R, and then In this way a defect in one of the wires in the Mismeer and Zandvoort cable was tested, for the fault was 544 knots from the English coast; and when the fault was cut out, the error was less than the one-third of a mile. The cable being 115 nautical miles in length, the error was less than 0.3 per cent. The author mentioned a case where the conductor was 120 miles in length, and the defect offered a resistance of from 1000 to 2000 miles, varying continually in amount. Plans Nos. 1 and 2 were tried, as also several others, but the results were very uncertain, and would not indicate the locality nearer than within 30 miles of the true position. This led him to invent plan No. 3, which left a possible error of only 2 or 3 miles. In this case the leakage due to all gutta percha, and which is very small, would have produced an error of 4 miles had it not been allowed for. Thus far conductors which are continuous, but whose insulation is defective, have alone been spoken of. When the cable or conductor is broken asunder, one of the following plans will indicate approximately the amount of resistance due to the fault itself. Case 4.-A cable broken asunder, if possible measure the resistance from each end; and if the exposed end of the broken cable offer only a very little or no appreciable resistance, the two amounts added together will be equal to that of one perfect wire; i. e. calling a one portion of the broken cable, and z the resistance of its exposed end, and y the other portion of the cable, and z' its ends' resistance, then if x+z+y+z'=S, the resistance of a perfect wire, it is evident that z+z' offer little or no appreciable resistance, and the locality of the fault is immediately known. When, however, z or z' offer resistance, the value of z may be approximated either by measuring the amount of electrostatic charge of the cable, or by measuring the resistance, first with negative and then with positive currents. It sometimes happens that one of the exposed ends of the conductor gets entangled with the iron outer wires of the cable. This is to be sought for; and if such be the case, it offers no appreciable resistance; this is immediately ascertained by connecting the conductor of the cable through a delicate galvanometer to the iron outer covering, when, if the copper wire at the fault be not in contact with the iron wires, an electric current will be found to flow through the galvanometer. The electromotive force of this current should be tested, and it will generally be found equal to an iron copper pair charged with sea-water. If the conductor touch the outer iron, there is no current through the galvanometer. If there be the current, 1st. Measure the resistance of +z with negative current, and note whether it varies in amount. 2nd. Measure the resistance as before, but with a positive current, and note how it varies. If it vary much, especially with the negative current, it indicates that the fault offers much resistance. 3rd. Make an artificial fault, or rather several faults, that behave like the cable, with a like resistance to that of the cable, and with the same battery power. Having made such a fault that resembles as nearly as possible the cable with positive and with negative currents of various powers, measure its resistance, and subtract that amount from x+z, and that will indicate the distance of the fault. The positive current decomposes the sea-water and its salts, oxygen and chlorine are set free and combine with the copper wire at the fault, forming a coating offering considerable resistance to the passage of the current. In this way the resistance of a fault may often be very considerably increased. If it can, it shows that the surface exposed at the defect is small, and offers considerable resistance even with a negative current. A negative current covers the exposed wire with hydrogen, which keeps it clean and in good contact with the water, unless the aperture admitting the water be very small, and located in shallow water, when the hydrogen will sometimes expel the water and so increase the resistance. The next plan of ascertaining the resistance of the fault, is by measuring the induction or statical charge and discharge. The author detailed several plans of doing this approximately, and indicated how an apparatus might be made to effect this perfectly, and which he had tried on a small scale with perfect success. He then showed how he had tested for the faults in the Atlantic Telegraph Cable, and pointed out the utter impossibility of the great fault being in the Valencia harbour, and which was proved by two distinct modes of testing. The exposed copper wire at the fault, formed with the iron outer covering a voltaic element of copper and iron. He contrived with this battery alone to measure the resistance of the cable and the fault. Much depends on the skill of the manipulator in choosing those plans most suited for the occasion. After detailing several curious defects, he showed that when the defect in a cable was small and immersed in clay-mud, the fault might often be sealed up by a positive current so completely as to enable the conductor to be used. In this way he had sealed up one of the Orfordness Scheveningen Cable, which was defective, and thus kept it working above eighteen months; and when it got bad, it was again and again sealed up by strong positive currents. He stated that he had used some of the plans described for the last twelve years, and had rarely, if ever, found a greater error in the estimated distance than 5 per cent. of the cable tested. The plans detailed, as far as the author was concerned, were original, save No. 2, which was partly borrowed from the Abbé Moigno's treatise on Electric Telegraphs. CHEMISTRY. On the Action of concentrated Sulphuric Acid on Cubebin in relation to the test for Strychnine by Bichromate of Potash and Sulphuric Acid. By JAMES S. BRAZIER, F.C.S., Fordyce Lecturer in Marischal College, Aberdeen. In the 'Chemical Gazette,' vol. xiv. page 251, there is an account by M. E. Boli, Professor of Chemistry and Mineralogy at the Academy of Medicine in Lima, of the behaviour of several organic substances towards bichromate of potash and sulphuric acid. All the substances enumerated by him appear to have a well-marked distinction by means of this test to that of strychnine, most giving a colour of some shade of green; some few, no reaction whatever. Casually repeating a similar series of experiments as a class illustration, with such alkaloids as I had in my possession, using at once KO, 2 CrSO, and HOSO,, I found that cubebin gave a reaction very different to many, and approached to some extent the reaction of strychnine, the colour produced being deep rose-red, which is perhaps more likely to be confused with the colour produced by strychnine, when the reaction has been standing for a short time, or if the alkaloid is in small quantity, or if the dish in which the experiment has been performed is not absolutely cold. I found, however, that by allowing the cubebin reaction to remain for some considerable time, the red colour gradually changed to a dingy green. On repeating the experiment in other ways, I found that the sulphuric acid alone was sufficient to produce this red colour with cubebine, and as strychnine produces no colour with sulphuric acid alone, this serves as an easy test between the two. The reaction above alluded to was quite new to me; nor could I find it noticed in any Journal; so that I thought it worthy of a comment on the present occasion. On Distilled Water. By JAMES S. BRAZIER, F.C.S., Fordyce Lecturer in Marischal College, Aberdeen. Notice of Dugong Oil. By JAMES S. BRAZIER, F.C.S., Fordyce Lecturer in Marischal College, Aberdeen. The author presented notices of a remedy, obtainable in Moreton Bay, possessing valuable properties for the renovation and restoration of the human frame when worn out and exhausted by chronic disease. The discovery of such an agent within our own territory has long been considered a desideratum by the profession; and it appears to be a remarkable as well as felicitous arrangement of nature, that, in a locality possessing probably one of the finest climates in the world-combining both the soft humid atmosphere of Torquay and Madeira in the summer, with the dry bracing air of Nice and Pau in the winter, the resort, too, of valetudinarians from all parts of the world-a remedy should be found so potent in the treatment of chronic disorders. About fourteen or fifteen years ago Baron Liebig's work on Animal Chemistry was first published, explaining the chemical process of respiration and nutrition, suggesting the method which ought to be adopted, and the principles which ought to guide us in the investigation of that important subject. Liebig, in that masterly work, compared the animal body to an apparatus of combustion, a furnace which we supplied with fuel, and showed that this combustion was supported by the oxygen of the atmosphere taken into the lungs in the act of respiration, meeting with the carbon taken into the system in the process of nutrition. Two or three years after the appearance of this work, a highly carbonized substance called codliver oil became a popular remedy in the treatment of consumption, to feed probably the flame of " the expiring lamp," as Kirke White in his Sonnet to Consumption' so beautifully yet significantly expresses it; and since that period its use has been progressively increasing, until at length its administration has become universal in almost every form of chronic disease. At first it was thought that the infinitesimal proportion of iodine which cod-liver oil contained was its active element; but that theory being now exploded, its powers are generally attributed to the 80 or 90 per cent. of carbon it contains. This oil is procured from the livers of cod fish, and its taste is as disagreeable as its train-oil-like odour. So unpleasant indeed is this oil, that there are very few persons who can take more than three or four tablespoonfuls in a day, which at the most will only yield 2 ozs. of carbon to the system, towards 13·9-10 oz. required, leaving a fearful balance against the sick man. Fortunately, however, the theory is better than the remedy commonly used, and the sick people of Australia are singularly favoured in having in their own territory an herbivorous cetaceous animal, the Dugong (Halicore Australis), inhabiting the rivers and bays of the eastern coast, from Moreton Bay to Cape York, from which an oil can be procured possessing all the properties required for this purpose. So sweet and palatable is the oil procured from the Dugong, that in its pure state it may be taken without disagreeing with the most sensitive stomach, and also used in a variety of ways in the process of cooking; so that this potent restorative remedy may be taken as food, and many ounces consumed almost imperceptibly every day, and thus furnish the system with the requisite amount of carbon for its daily oxidation. Believing Elaiopathy, or oil administration, to be a rational mode of treatment, and dissatisfied with the nauseous train-oil-like fuel usually supplied to our sickly furnaces, the author made diligent search for a substitute, and now unhesitatingly communicates, after testing the powers of the discovery for nearly five years in a great variety of chronic disorders, that the Dugong oil is one of the most potent and reliable remedies he has ever met with in the treatment of chronic disease. Laboratory Memoranda. By J. S. BRAZIER, F.C.S., Fordyce Lecturer in Marischal College, Aberdeen. On the quantitative estimation of the soluble combustible contents of a water. This item of an ordinary analysis of a water, which commonly passes under the general description of "organic matter," is frequently obtained as follows:-by evaporating a portion of the water to dryness, to weigh the residue, and afterwards to heat it to low redness till it ceases to lose weight, when the difference from its former weight would be considered the "organic matter." In burning off the combustible portion of the total dry evaporated contents, two chief sources of error may be observed:-first, carbonic acid is apt to be expelled from the incombustible mineral contents by the action of the combustible matter under a high temperature, the residue giving an alkaline reaction to test paper; second, when a very high temperature is applied in order to burn off the combustible portion, some of the incombustible mineral portion is volatilized, and thus comes to be erroneously reckoned as part of the combustible soluble contents. In consequence of these observations, the following method of procedure is adopted by the author. The evaporating basin is of platinum, about 600 grains in weight, and about a quarter of a pint in capacity. The measure of water evaporated in each trial is one-fifth of a gallon (=14,000 grains). To prevent any minute increase of weight from fused adhesions to the outside of the basin during long exposure to flame, heat is applied by means of a water-bath. The evaporated mass is dried in a Taylor's hot-air bath at a temperature of 230° Fahr., and is then weighed. The nett weight gives the total soluble contents, both combustible and incombustible. A temperature of 260°, as often as it was tried, gave no differance in the weight. The scorching is produced by heating the outside of the evaporating basin by the flame of a spirit-lamp, kept as weak as can burn off the combustible matter. The evaporated mass, after being scorched, is moistened with a solution of pure carbonic acid in distilled water, is dried anew in a Taylor's air-bath at 230° Fahr., and is weighed a second time. The nett weight gives the incombustible (or mineral) soluble contents alone, which on being subtracted from the former nett weight of both combustible and incombustible, left the combustible alone. The heat of the spirit-lamp is preferable on account of the variation which is so frequently caused in platinum vessels by heating them over a gas-flame; apparently some carbon compound is produced, and, in proportion to the more or less perfect combustion of the gas flame, the platinum dish becomes lighter or heavier, thus causing an error in the weight of the contents of the dish. An increase in the measure of water evaporated fails to increase the accuracy of 1859. 17 the results; for an increased quantity of mineral matter makes the thorough com bustion of the evaporated mass more difficult, and so necessitates the application of a very high temperature, which produces error, by volatilizing a portion of the mineral matter. This is not an exact method of estimating combustible or organic matter, there being none; still it is as correct as any known, and affords uniform results, which the ordinary process assuredly does not. Mr. C. J. BURNETT exhibited some specimens illustrating the use of Platinum in Photography. On the Ageing of Mordants in Calico Printing. By WALTER CRUM, F.R.S. The process of "ageing" in calico printing is that by which a mordant after being applied to a cotton fabric, is placed in circumstances favourable to its being incorporated with and fixed in the fibre; and the method usually employed has been to suspend mordanted goods in an apartment in single folds, exposed to the atmosphere. The object is to moisten the acetates of iron and of alumina in order to their decomposition; and in ordinary circumstances a pound of water is gradually absorbed by fifteen pounds of printed cloth. The protoacetate of iron is thus enabled, by imbibing oxygen, to become a sesquiacetate like the bisalt of alumina. Each then proceeds to give off acetic acid, and to deposit a tersesquihydrate upon the fibre. Various methods have been employed in this country for adding to the natura. moisture of the air, but with no great advantage, until Mr. Jones introduced into Messrs Schwabe's works near Manchester a system of ageing which he had seen in operation at Mulhausen, and succeeded, by the direct introduction of steam underneath, greatly to increase the heat and moisture of the large apartment in which his mordanted goods were hung, and thus to render the process of ageing not only more speedy, but much more perfect than before. But the employment of steam was in that case limited in amount, chiefly by the discomfort to which it subjected the work people in the apartment, and by the damage produced by drops of water falling from their persons upon the goods. In the summer of 1856, Mr. Jones visited Thornliebank, and described that method of ageing. It became then not difficult to conceive that, by a further increase of heat and moisture in an apartment sufficiently capacious, and by employing a great number of rollers, goods might become sufficiently moistened without manual labour by being merely passed through such an atmosphere; and that thus, the pieces being stitched end to end, a continuous process might be substituted for that of hanging goods over wooden rails, and leaving them there until the ageing is completed. The idea of passing printed goods through an atmosphere artificially moistened was not new. It had even been patented by Mr. John Thom of Manchester; but the apparatus of that gentleman was too small to be practically useful. The present improvement consists in rendering the process a practicable one; and the various adaptations introduced for that purpose will appear in its description. A building is employed 48 feet long inside and 40 feet high, with a midwall from Dottom to top running lengthwise, so as to form two divisions each 11 feet wide. In one of these divisions the goods first receive the moisture they require. Besides the ground floor, it has two open sparred floors 26 feet apart, upon each of which is fixed a row of tin rollers, all long enough to contain two pieces of cloth at their breadth. The rollers, being threaded, are set in motion by a small steam-engine, and the goods to be aged, which are at first placed in the ground floor, are drawn into the chamber above, where they are made to pass over and under each roller, issuing at last at the opposite end and folded into bundles on one (at a time) of three stages which are placed there. These stages are partially separated from the rest of the chamber by a woollen partition. While the goods are traversing these rollers, they are exposed to heat and moisture, furnished to them by steam, which is made to issue gently from three rows of trumpet-mouthed openings. The temperature is raised to from 80 to 100° or more of |