We annex illustrations of a meter designed by Mr. A. Schmid, of Zürich, and which, according toEngineering, is now considerably used on the Continent, not only for measuring water, but the sirup in sugar factories, in breweries, etc. It consists of a cast iron body containing two gun-metal-lined cylinders, and connected by an intermediate chamber. Round the body are formed two channels, one for the entrance and the other for the discharge of the water, etc., to be measured. Within the cylinder are placed two long pistons, provided with openings in such a way that each piston serves as a slide valve to the other, the flow being maintained through the ports in the connecting chamber. The arrangement of openings in the piston is shown in Figs. 5, 6, 7, and the intermediate passages in Figs. 1, 2, and 3. To the upper side of each piston is attached a cross-head working on a disk placed at each end of a horizontal shaft. To one of the disks is added a short connecting rod that drives the spindle of a counter.
SCHMID'S WATER METER.
SCHMID'S WATER METER.
The washing machines in use for wool on the rake principle have during the last few years experienced many improvements in the details of their arrangement, which we have illustrated at different times in our columns. The introduction of these improvements and alterations shows that the washing of wool has attracted more attention on the part of observant manufacturers and machine makers, and demonstrated at the same time that the machines hitherto in use, with all their advantages, left much to be desired in other respects. The main difficulty with all washing machines for wool has been the avoidance of felting of the wool, which tendency is increased by the use of warm water for washing and by the agitation that some consider necessary for a thorough cleansing of the wool and removal of the adhering impurities, but which agitation is deprecated by others.
IMPROVED WOOL WASHING MACHINE.
IMPROVED WOOL WASHING MACHINE.
Referring to our different illustrations of improvements in this direction, our subscribers will observe that the tendency of all these has been to keep the wool floating in the water, and to apply all mechanical appliances required for its cleansing and pressing as much as possible while it is in this suspended condition. The success which the different appliances and improvements mentioned by us have had when used for the class of wool for which they are intended, has induced us to look up any attempts in a similar direction which have been made on the Continent, where the subject has attracted attention, as well as with us. We therefore give the annexed illustration of a machine invented by a German woolen manufacturer, which in many respects is a wide departure from the acknowledged type in use in this country. As with the English machines, the wool enters from a creeper at one end, passes through a long trough, filled with water or lye, ascends an inclined plane, and passes out through a pair of squeezing rollers. The invention mentioned applies to the treatment in the trough which latter is shown in our illustration at K. It has a second bottom, a little distance from a false one, at K. The false bottom is traversed in its whole length by an air pipe, communicating with the atmospheric air outside the trough. From this longitudinal pipe other pipes branch off at right angles at stated intervals, as shown in section in Fig. 2. These smaller pipes contain a number of small perforations on their upper part, through which the air ascends into the water in innumerable small bubbles. This is one of the principal aims of the invention, for in ascending the bubbles lift the wool more or less to the surface and tend to open it out without the risk of doing so by any mechanical means liable to produce felting. This is the same effect that is produced in many cases so successfully in boiling. Instead of rakes the inventor has placed four hexagonal drums into the trough, marked D, E, F, G. The flat parts of these drums are made of perforated metal and set back a little. This produces an alternate passing of the water into and out of them during their revolution and consequent sucking and repulsing of the wool, which also likewise agitates it. These drums are made wide at the entrance end of the trough and gradually narrower toward the delivery end. The pipe, V V, is the usual steam pipe for heating the water.
We have said before that the improvements introduced into the wool washing machines nearer home have been of advantage for the wools for which they are intended, and possibly the invention just described will also be valuable in some cases.--Tex. Manuf.
This invention relates to lighting by mixing air or other gaseous supporter of combustion with illuminating or other hydrocarbon gas or vapor, and burning the mixture (at a suitable pressure) in a burner of special construction, shown in the accompanying illustrations.
The burner is constructed as shown in Figs 1 and 2. It consists of a central tube, i, screwing upon the pipe by which the gaseous mixture is supplied. Upon this tube is screwed a cup, k, of metal or refractory material which supports a cap, l, of fire-clay in the shape of a thimble (or of other form, according to the intended use of the burner). The flanged base of this cap is perforated with a ring of holes, m, as small and numerous as possible, and the sides of the cap are pierced with oblique perforations, n. The top of the tube, i, is provided with four small projections, upon which rests a copper cone, o, soldered to the tube at a point below the perforations in the base of the thimble. The cone is perforated at its lower end with small holes, p, the sum of whose areas is at least equal to the area of the tube. The thimble, l, is surrounded by an envelope, q, of platinum wire netting or other refractory material of the same form. The gaseous mixture arriving by the pipe, i, escapes at the upper orifices, r, and passes down against the interior surface of the cone, o, out at the orifices, p, and escapes through the orifices in the cap, l, at which it is burned. The cap is thereby raised to a high temperature; and the platinum wire sheath becoming incandescent radiates the light. The gaseous mixture, by coming first in contact with the copper cone and then with the refractory cap, becomes raised to an exceedingly high temperature before it is consumed.
In the modified burner represented in Fig. 3, the metal cone and the fire-cap are truncated. The tube, i, is provided with a number of small perforations, r, at its upper end, the sum of whose areas is at least equal to the area of the tube, and by which the gaseous mixture is distributed within the chamber, k. Upon the upper closed end of the tube is fixed a cup or inverted thimble, o, of fire-clay. A refractory cone, l, surrounds this cup and rests by its base upon the cup. This flanged base is perforated with small vertical holes, m, and upon it is fixed a platinum wire cage or envelope, q. An annular space is left between the cone and cup for the passage of the gaseous mixture, which, on escaping from the orifices, r, passes over the exterior surface of o, the interior of which is already heated by the flame which has not passed through the wire gauze, and has been forced by the pressure of the mixture into the interior of o. The gaseous mixture before passing through the annular space thus attains such a temperature that on escaping from the orifice its combustion is greatly promoted.
In the present state of civilization the use of iron has reached a very wide extension, and in a great number of cases iron is used where wood or stone was formerly used. It is certainly an important question how this metal can be protected under all circumstances against rust or oxidation, so that the many costly iron structures may retain their usefulness and strength, and be handed down uninjured to posterity.
Wherever bright iron comes into contact with air and moisture it immediately begins to rust, and this rust is not content to continually rob it of its substance in its persistent progress by scaling off the surface, but at the same time it injures the remainder of the iron by making it brittle. Attempts have hitherto been made to protect the iron by covering it with other and less easily oxidizable metals. For this purpose tin was first selected, then lead and zinc, and recently nickel. Furthermore, earthy glazings and enamels, such as are used on stone ware, have been applied to iron vessels, and they have already found extensive use in the household. In most cases these coatings, either metallic or vitreous, are inapplicable, either because they cannot be applied or are too expensive, so that on a large scale recourse must be had to paints made by mixing oils with metallic oxides, earths, etc., for protecting the surface of the iron from air and moisture.
It has been observed that iron does not rust indryair, not even in dry oxygen. In like manner it frequently happens that unpainted iron, such as weather vanes, fences, etc., is exposed to the air for a century with very little injury, being covered with a thin coating of the magnetic oxide (proto-sesquioxide), which acts as a protection and prevents farther action. Hence it has been proposed to produce a layer of this magnetic oxide on the surface artificially, and it was found that superheated steam furnished the means for doing this. But it is not to be supposed that such a process would find use on a large scale, and besides this protection could only serve for iron tolerably exposed to the open air and not for that in direct contact with carbonic acid and water.
An interesting observation has been made on railways that the iron rails, ties, bolts, etc., rust until the road begins to be used. Here we must assume that anything made of iron is more inclined to rust when at rest than if occasionally caused to vibrate, when an electrical action probably comes into play and decreases the affinity of iron for oxygen.
In tearing down old masonry iron bonds and clamps are often found which are as free from rust, so far as they are covered with mortar, as they were the day they left the blacksmith's hands. A French engineer met with such a phenomenon when he uncovered the anchor plates of several chain bridges which had been built about thirty years. Where the anchors were covered with the fatty lime mortar of the masonry they showed no traces of rust, but the prolongations of the anchors in empty spaces were rusted to such an extent that they were only one-third of their original thickness.
It has been repeatedly observed that iron does not rust in water in which are dissolved small quantities of caustic alkalies or alkaline earths, which neutralize every trace of acid. It seems that these experiences are the basis of A. Riegelmann's (Hanau) new protection against rust. The paint that he uses contains caustic alkaline earths (baryta, strontia, etc.), so that the iron is in a condition similar to the iron anchors of the chain bridges that were embedded in lime mortar. Although a paint is not thick enough to inclose so much alkali as the masonry did that the iron was embedded in, nevertheless the alkaline action will make itself felt as long as the coating has a certain consistence. Under all circumstances, however, these new paints will be free from active acids, which is more than can be said of our iron paints hitherto in use. Besides this, the rust protector has such a composition that it could serve its intended purpose without the addition of any alkali. If experience confirms this claim, it will be an interesting step forward in the preservation of iron, and contribute to an extension in the use of iron.--Polytechn. Notizblatt.
SUGGESTIONS IN DECOTATIVE ART.--A CUPBOARD IN ITALIAN WALNUT WITH DARKER PANELING.--From The Workshop.
SUGGESTIONS IN DECOTATIVE ART.--A CUPBOARD IN ITALIAN WALNUT WITH DARKER PANELING.--From The Workshop.
It should be made in a well glazed earthen crock; metallic vessels are not good, as the gelatine burns too easily on the sides, and dries out where it gets too hot. Nor is a water bath to be recommended for dissolving the gelatine, for the sides get too hot and dry out the gelatine.
A quart of water is put in the crock and heated to boiling; it is then taken off the open fire and two pounds of the finest gelatine stirred in, a little at a time. After the gelatine is completely dissolved there is to be added eight or ten pounds (according to the quality of the gelatine) of the finest white sirup previously warmed, and constantly stirred. The mass must not boil, as it would easily burn, or turn brown and acquire a bad color.
Thirty or forty pounds of a beautiful white elastic mass can be made by this recipe in an hour at a cost of ten or twelve cents. Its chief use is for making figures and ornaments to put on bridal cakes and other fanciful productions of the confectioner. It contains no harmful ingredients and can be eaten without danger. If coloring is added, cochineal, plant green (chlorophyl), and turmeric are safer than aniline colors.
A. Levy contributes the following brief account of this subject to theMoniteur Scientifique:
The crude gum cut in irregular strips is passed five or six times between two strong rolls sixteen inches in diameter, and making two or three revolutions per minute. These rolls are kept wet by water trickling on them. This broad strip of gum is perforated with foreign substances and looks like a sieve. It is next put in the cutting machine, a horizontal drum provided with an axle having knives on it. So much heat is produced by this cutting that the water would soon boil if it were not renewed. A second machine of this kind completes the cutting and subdividing, and expels the air and water from it. The mass is then pressed in round or quadrangular blocks.
The vulcanization of thin articles from one twenty-fifth to one-sixteenth inch thick, is done by Parkes' patented process, that is, dipping it in carbon disulphide for a short time, to which chloride or bromide of sulphur has been added, and when the solvent has evaporated the sulphur remains behind. Balls, ornamental articles, and surgical apparatus are dipped into melted sulphur at 275° or 300° Fahr.
The third most important process consists in mixing in the sulphur mechanically with the gum in the cutting machine.
After the pieces have received the form they are to have they are heated with steam or hot air to 275°. Flat articles are vulcanized between press plates heated by steam. This vulcanization is said to have been discovered accidentally by searching different colored stuffs, some of which were dyed yellow with sulphur; the latter stood well.
Hard rubber contains more sulphur, and is heated longer and higher. Small or fine tubes and hose are made by a continuous machine that presses it through a hole with a core to it. Large hose is made by wrapping strips around iron rods or tubes. The little air balloons are made in Paris (their value is $300,000) by Brissonet from English Mackintosh cloth. Powdered soapstone is strewed over it in cutting. The edges are united by hammering on a horn anvil, or by machinery through simple adhesion, and the cut surfaces are smooth.
At the last meeting of the Chemical Society Captain Abney gave a lecture on the above subject to a large audience. We may premise by saying that the demonstrations he gave were carried out principally by means of experiments on paper, to enable his hearers to understand the different points he wished to enforce. The lecture was commenced by insisting on the fact that all photographic action took place within the molecules of the compound acted upon and not on the molecule itself, and from this he deduced that the absorption of radiation which take place by such compounds is principally caused by the atoms composing the molecule. This was found to be the case in the organic liquids, which the lecturer to some extent had investigated, where he had further traced the absorption to the vibrating atoms of hydrogen in those bodies. In order to properly investigate the action of light it was necessary to ascertain which components of light in the spectrum were the chief agents in causing it, and this led him to consider the means to be employed to obtain a spectrum.
The effects of diffraction gratings were first discussed, and in two which were shown it was found that in some spectra the visible portions were dimmed; in others the ultra-violet and the infra-red were almost entirely absent. It thus became necessary to investigate the condition of a grating before placing any confidence in the results obtained. This was the first pitfall into which an experimentalist was liable to fall. If prisms were used for obtaining the spectrum, then precautions had also to be taken, since all glass absorbed a portion of the ultra-violet rays and some the infra-red. On the whole, he considered that the best glass to use was pure white flint glass for the collimator, the prisms, and the camera lens. Another inquiry that was necessary was the source of radiation which it was proposed to use. Diagrams showed the unsatisfactory nature of solar radiation, and a photograph of the whole spectrum, taken with it under certain atmospheric conditions in which the effect of the green rays were almostnil, demonstrated the false conclusions that might be deduced as to the sensitiveness of any particular compound.
Captain Abney also showed the satisfactory conditions which existed in using the crater of the positive pole of the electric arc light as a source, and by diagrams illustrated the inferiority of an incandescent light for the purpose, owing to the deficiency of violet and ultra-violet rays. Having thus settled the source of illumination and the kind of apparatus to employ, he next considered the conditions under which the sensitive salts were to be exposed. The action of ordinary sensitizers was explained and demonstrated by experiments, from which point the results of certain colored sensitizers were considered. Thus, various aniline dyes were proved to be bromine absorbents, and likewise, more or less, to be capable of being acted upon by light in those regions of the spectrum they absorbed. The result of the two effects was to produce a developable image of the spectrum just in those parts to which the salt of silver was sensitive, and also in the parts where the dye itself was acted upon. The latter effect was traced to the organic matter being oxidized in the presence of the sensitive silver salt.
The sensitizing effect of one silver compound upon another was then gone into, and experiments and photographs showed where two salts of silver were in contact with one another, and without an energetic sensitizer being at hand, that the one when acted upon by light absorbed the halogen liberated from the other through the same cause and that a new molecule was formed. This was of importance, since in photographic spectroscopic researches a conclusion might be arrived at that a body suffered absorption in those regions of the spectrum where this interesting reaction took place, whereas in reality the phenomenon might be due to the silver salts employed. This was another pitfall for the unwary. Again, it became necessary in studying photographic action to make sure that the effect of radiation was only a reducing action, and that the results were not vitiated by some other action.
The destruction by oxidizing agents of the effect produced by light was then experimentally demonstrated, and photographs of the spectrum showed that this effect was increased by the action of light itself. Thus, when immersing a plate sensitive to all radiations, visible and invisible, in a very dilute solution of nitric acid, bichromate of potash, or hydroxyl, it was shown that if the plate were exposed to light, first the parts acted upon by the red rays were reduced before the parts not acted upon at all by the spectrum, thus conclusively proving that light itself helped forward the oxidation or so-called solarization of the image. It thus became a struggle, under ordinary circumstances, between the reducing action on the normal salt and the oxidizing action on the altered salt as to which should gain the mastery. If the reducing action of any particular ray were the most active, then a negative image resulted, whereas if the oxidizing action were in the ascendant, a positive image resulted. Thus, in determining the action of light on a particular salt, this antagonism had to be taken into account, and exposure made with such precautions that no oxidizing action could occur, as would be the case if an inorganic sensitizer, such as sulphite of soda, were used.
The reversal of the image by soluble haloid salts, such as bromide of potassium, was then dwelt upon with experimental demonstration. It was shown that the merest trace of soluble haloid would reverse an image by the extraction of bromine from it, and the fact that the most refrangible part of the spectrum was principally efficacious in completing this action showed how necessary it was to avoid falling into error when analyzing photographic action by the spectroscope. A reference was next made to gelatine plates, in which, owing to their preparation, reversal through the above cause was most likely to take place, and a plate soaked in sulphite of soda and exposed in the camera for a couple of minutes--a time largely in excess of that necessary to give a reversal under ordinary circumstances--proved the efficacy of the oxygen absorber, the image remaining in its normal condition after development.
The lecturer closed his remarks by showing the different molecular states of iodide, bromide, and chloride of silver, as produced by different modes of preparation. The color of the film by transmitted light in every case indicated the effect which was likely to be produced on them, and the photographed spectrum in each of them showed the remarkable differences that were found. The points raised by Captain Abney at different times are well worthy the study of scientific photographers, since strict attention to the modes of exposure to the spectrum, to the instruments employed, and to the source of light used can alone insure accuracy in comparative experiments.--Br. Jour. of Photo.
M.F.K. communicates the following interesting circumstance toNeueste Erfindung.: A few years ago it was decided to whitewash the walls and ceiling of a small cellar to make it lighter. For this purpose a suitable quantity of lime was slaked. A workman who had to carry a vessel of common salt for some other purpose stumbled over the lime cask and spilled some of his salt into it. To conceal all traces of his mishap he stirred in the salt as quickly as possible. The circumstance came to my knowledge afterward, and this unintentional addition of salt to the lime excited my liveliest curiosity, for the whitewash was not only blameless, but hard as cement, and would not wash off.
After this experience I employed a mixture of milk of lime and salt (about three parts of stone lime to one part of salt), for a court or light well. To save the trouble and expense of a scaffold to work on, I had it applied with a hand fire engine (garden syringe?) to the opposite walls. The results were most satisfactory. For four years the weather has had no effect upon it, and I have obtained a good and cheap means of lighting the court in this way.
It is stated in theGewerbeblatte fur Hessenthat paint can be renewed and refreshed in the following manner:
When cracks and checks appear in the paint on wooden articles, this usually indicates that the varnish has cracked. If this is the case, the article can easily be prepared for a fresh coat by sponging it over with strong ammonia water, and two or three minutes later scraping off the varnish with the broad end of a spatula before the ammonia has dried up.
In this way the first coat is removed. If it is necessary to remove the next coating, the same operation is repeated. After the last coat has been scraped off that is to be removed, it must be washed with sufficient water to render the ammonia inactive, and then the surface is rubbed with pulverized pumice to make it smooth. Any desired paint or varnish can be applied to a surface prepared in this way.
There is no department in analytical chemistry in which so little success has been attained as in the testing of commercial fats and oils. All methods that have been proposed for distinguishing and recognizing the separate oils, alone or mixed, bear upon them the stamp of uncertainty.
The facts observed by J. Koenig, and described by him in his excellent book entitled "Die Menschlichen Nahrungs und Genussmittel" (p. 248), excited great expectations; viz., that the quantity of glycerine in vegetable fats was much less than the amount required to combine with all the fatty acids, and that the quantity of oleic acid in the oils that he examined exhibited essential differences. Koenig himself asserts that the fats have hitherto been too little investigated to found upon it a method for distinguishing them, but that nevertheless it may possibly do good service in some cases.
My own estimation of the amount of glycerine in different olive oils, by Koenig's method, has shown, unfortunately, that the percentage may vary from 1.6 to 4.68, according to the origin and quality of the oil. In like manner the estimation of the oleic acid, which was conducted essentially in the manner proposed by Koenig, showed that the amount of oleic acid in different olive oils varied from 45 to 54 per cent. But since cotton seed oil, for example, which is most frequently used to adulterate olive oil, contains 5 per cent. of glycerine, and 59.5 per cent. of oleic acid, it is easy to see an admixture of cotton seed oil cannot be detected by this method, which appeared to be so exact.
The method of analysis that I am about to describe is based chiefly upon the determination of the melting point of the fatty acids contained in the oils, and upon their solubility in a mixture of alcohol and acetic acid.
The oils employed in adulterating olive oil, and to which regard must be had in testing it, are the following: Cotton seed oil, sesame, peanut, sun flower, rape, and castor oils. The tests for the two last named have hitherto never presented any difficulty, as rape seed is easily detected, owing to the sulphur in it, by saponifying it in a silver dish, and castor oil by its solubility in alcohol. But in recent times another product has come into the market called sulphur oil or pulpa oil, obtained by extracting the pressed olive cake with sulphide of carbon. This also gives a sulphur reaction when saponified, while it resembles castor oil by its solubility in alcohol. When this oil is mixed with ordinary olive oil, it can easily deceive any one who uses the ordinary tests.
My method of testing olive oil is as follows:
First, the so-called elaidine test is made, and then the test with nitric acid. About 5 c. c. (a teaspoonful) of the oil is mixed in a test tube with its own volume of nitric acid, spec. gr. 1.30, and shaken violently for one minute. At the expiration of this time the oils will have acquired the following colors: Olive oil, pale green; cotton seed oil, yellowish brown; sesame, white; sun flower, dirty white; peanut, rape, and castor oils, pale pink or rose.
As soon as the color has been observed, the test glass is put in a water bath at the full boiling temperature and left there five minutes. It was found that the action of nitric acid upon cotton seed and sesame oil was the most violent, sometimes so violent as to throw the oil out of the glass. At the end of another five minutes after the test tube is taken out of the water bath, the following colors are seen: olive and rape oils are red; castor oil is golden yellow; sun flower oil, reddish yellow; sesame and peanut, brownish yellow; cotton seed, reddish brown.
After standing 12 to 18 hours at about 60° Fahr. the olive, rape, and peanut oils will have solidified; sun flower, castor, and cotton seed will be like salve (sticky), while sesame will remain perfectly liquid. Mixtures of olive oil with small quantities of cotton seed or sesame are distinguished by this characteristic--that, although the whole mass, which is darker in color than olive oil, solidifies at first, at the end of 24 or 36 hours a brown oil will be found floating upon the surface of the solid mass, while the lower strata exhibit the yellow color of pure olive oil. Oil of rosemary has no effect when shaken with cold nitric acid, and imparts to it only a slightly darker color on heating. Oils treated with lye act just like pure oils.
Far the purpose of determining the melting point of the fatty acids, 10 grammes of oil were saponified with 5 grammes of caustic potash on the water bath; some water and alcohol being added. After all the alcohol had been expelled the soap was dissolved in hot water, and the fatty acids separated from the clear solution by adding hydrochloric acid. After prolonged heating these acids will swim on the salt solution as a perfectly clear oil, a portion of which is then put into a little, narrow, thin walled tube and allowed to solidify. The point at with it melts and solidifies is determined by putting this tube in a beaker glass filled with water and warming with a small flame. A thermometer is placedinthe fatty acids and moved gently about during the observation, and the point accurately observed at which the whole mass becomes perfectly clear, and also when the mercury bulb begins to be clouded. It was found that the acids from pure olive oil melt between 26½ and 28½° C. (= 80° to 83° Fahr.) and solidify at a point not lower than 22° C. (72° Fahr.). The melting point of the fatty acids in the oils used to adulterate olive oil differs considerably from this. The melting and solidifying points of the acids in cotton seed, sesame, and peanut oils lie considerably higher, those of sunflower, rape, and castor oils decidedly lower than those of olive oil.
The melting and solidifying points of these acids are as follows:
Cotton seed melts at 38.0°C. solidifies 35.0°C.Sesame do. 35.0 do. do. 32.5 do.Peanut do. 33.0 do. do. 31.0 do.Sunflower do. 23.0 do. do. 17.0 do.Rape do. 20.7 do. do. 15.0 do.Castor oil do. 13.0 do. do. 2.0 do.
The above figures differ so much from those of olive oil, that adulteratious carried to the extent that they are in trade can easily be detected by the aid of an estimation of the melting point, for a Gallipoli olive oil, mixed with 20 per cent. of sunflower oil, melted at 24° C. and solidified at 18° C. (of course, the fatty acids are meant). A Nizza oil, mixed with 20 per cent. cotton seed oil, melted at 31½° C. and solidified at 28° C. A Gallipoli oil with 33-1/3 per cent. of rape oil melted at 23½° C. and solidified at 16½° C. When 0.50 per cent. of rape is added, it melts as low as 20° and solidifies at 13½° C., etc.
In testing the solubility of the fatty acids in alcohol and acetic acid, I employ the method proposed by David (inComptes Rendus, 1878, p. 1416) for estimating stearic acid.
It depends upon the principle that when acetic acid is poured drop by drop into an alcoholic solution of oleic acid, there comes a time when all the oleic acid separates, but stearic acid, which is insoluble in a mixture of alcohol and acetic acid, remains insoluble if the mixture contains oleic acid.
The following manipulations are adopted in testing olive oil: Equal parts of glacial acetic acid and water are mixed in a bottle. Then 1 c.c. of pure oleic acid, 3 c.c. of 95 per cent. alcohol, and 2 c.c. of acetic acid are put in a small tube graduated in tenths of cubic centimeters. The solution should remain clear; on adding another one-tenth c.c. of acetic acid it becomes turbid, and when 1 c.c. of oleic acid (or at first even more) floats on the mixture of acid and alcohol, the liquid is ready for use. If this is not the case, the proportions (of acetic acid and alcohol?) must be varied until the addition of one-tenth c.c. of the former will cause all the oleic acid to separate. The proportions having been ascertained from these preliminary experiments, the alcohol and acid are then mixed accordingly, e.g., 300 of alcohol to 225 of acid. One or two grammes of stearic acid are added to the alcoholic acetic acid, and the clear supernatant liquid used for the experiments.
One cubic centimeter of the oil (acids) to be tested is put in the tube, and 15 c.c. of alcoholic acetic acid added, well shaken, and the whole left to stand quietly at 15° C. (60° Fahr). If the olive oil is pure, the acids dissolve to a clear solution that remains so. Cotton seed oil is insoluble, and the solution obtained by heating the solution solidifies at 60° Fahr. to a white jelly. Sesame and peanut oil react in a similar manner. Sunflower oil dissolves, but at 60° a granular precipitate falls. Rape oil is entirely insoluble and floats like oil on the surface. Castor oil on the contrary dissolves completely, just like olive oil, and hence cannot be detected therein by this method. To detect this oil we must take the melting point of the acids along with the solubility of the oil itself in alcohol.
Olive oil when mixed with 25 per cent. of cotton seed oil yields a granular precipitate, and so does 25 per cent. of sesame. Smaller quantities cannot be detected by these methods. For rape oil the limit is 50 per cent., and in smaller quantities the oil does not collect on the alcoholic solution. The decided lowering of the melting point of the fatty acids in combination with the sulphur reaction, and the insolubility of the oil in alcohol, also furnish a method of detecting when present in smaller quantities in olive oil.
Although I am well aware that I am making public a research that is by no means free from objections, I nevertheless believe that it may be of use to those who have to undertake the ticklish and intricate analyses of commercial fats.--Translated from the Chemiker Zeitung, p. 355.
Leipsic, Jan., 1883.
In a note presented to the Industrial Society of Mulhouse, A. Pabst discusses the different stages in the formation of compound ethers, as Williamson has explained the production of ordinary ethers by the action of sulphuric acid upon alcohol. Pabst has observed that the compound ethers are formed in an analogous manner. If alcohol, sulphuric acid, and acetic acid are heated together, acetic ether, we know, is formed.
Pabst has shown that it takes place in three stages. In the first stage, ethyl sulphuric acid and water are formed; in the second, acetate of ethyl with the reproduction of sulphuric acid, which again converts a fresh quantity of alcohol into ethyl sulphuric acid.
(1) C2H5OH+HO,SO2OH = C2H5O,SO2OH+H2O.(Alcohol.) (Sulphuric acid.) (Ethyl sulphuric acid.)
(2) C2H5O,SO2OH+C2H3O,OH =(Ethyl sulphuric acid.) (Acetic acid.)
C2H5O,C2H3O+HO,SO2HO.(Acetate of ethyl.) (Sulphuric acid.)
Pabst proved this by letting methyl sulphuric acid act upon a mixture of acetic acid and ethyl alcohol. He obtained by this process acetate of methyl and ethyl sulphuric acid. By the continued action of ethyl alcohol and acetic acid upon this mixture, of course, acetate of ethyl was formed. At the conclusion of the operation there was no longer any methyl sulphuric acid present in the liquid.
In the course of his investigations, Pabst was led to a very practical method for preparing acetate of methyl, which consists in heating ethyl sulphuric acid to 135° or 140° C, and allowing a mixture of equal molecules of strong alcohol and acetic acid to flow into it.
The details of his experiments and the method of purification will be published by the society.
The French brass castings and articles of sheet brass are made of cheap, light colored brass, and possess a fine golden color which is not produced by gold varnish, but by a coating of copper. This gives them a finer appearance, so that they sell better.
This golden color can be easily produced at very little expense and with but little trouble by the following process. Fifty grammes of caustic soda and 40 grammes of milk sugar are dissolved in a liter of water and boiled for a quarter of an hour. The solution is clear as water at first, but acquires a dark yellow color. The vessel is next taken from the fire, placed on a wooden support, and 40 grammes of a cold concentrated solution of blue vitriol stirred in. A red precipitate of suboxide of copper is at once formed, and by the time the mixture cools to 167° Fahr., the precipitate will have settled.
A suitable wooden sieve is placed in the vessel, and on this the polished articles are laid. In about one minute the sieve is lifted up to see how far the operation has gone, and at the end of the second minute the golden color is dark enough.
The sieve and articles are now taken out, and the latter are washed and then dried in sawdust. If the brass is left longer in the copper solution, in a short time a fine green luster is produced, becoming yellow at first and then bluish green. After it turns green, then the well-known iridescent colors finally appear. To obtain uniform colors it is necessary that they be produced slowly, which is attained at temperatures between 135° and 170° Fahr.
The copper bath can be used repeatedly and can be kept a long time if bottled up tightly without change. After it is exhausted it can be renewed by adding 10 grammes of caustic soda, replacing the water that has evaporated, heating to boiling, and adding 25 grammes of a cold solution of blue vitriol.
Similar operations with other well known reducing agents, such as tartrate of soda, glycerine, etc., do not give such good colors, because they do not precipitate the copper solution so rapidly and at so low a temperature.
If the rinsed and pickled brasses are dipped for five minutes in a three per cent. neutral solution of cocoa nut oil soap, and then washed with water again before they dry, the coating gains in permanence.
Brass articles that have to be cleaned frequently should be covered with oil of turpentine, or thin English copal varnish.--Neueste Erfind.
Hermann Kratzer, of Leipsic, communicates the following practical information on the clarification and purification of vinegar to theNeueste Erfindungen und Erfahrungen:
If vinegar has an unpleasant odor, which is rarer now that the vinegar manufacture has reached such a state of perfection, it may be removed as follows: Well burned and finely pulverized wood charcoal is put into the bottles containing the vinegar, the proportions being 8 grammes of charcoal to a liter of vinegar, or one ounce to the gallon. It is shaken several times very thoroughly, then left standing three or four days, and the vinegar filtered through a linen cloth. Vinegar treated in this manner will be found to have completely lost its unpleasant odor.
I have found that when I used blood charcoal or bone coal in place of wood coal it was still more efficient; but it must be mentioned that when they are used they must be purified as follows before using: Charcoal from blood contains potash and hence it is necessary to wash it with distilled water and dry it before using it. Bone coal (also called bone black, animal charcoal, etc.) contains on an average 10 per cent. of nitrogenous and hydrogenated carbon, 8 per cent. of carbonate of lime, 78 per cent. of phosphate of lime, besides phosphate of magnesia, sulphate of lime, soluble salts, etc. Before using, it should be treated with dilute hydrochloric acid until it does not effervesce any more. The bone coal is then left to stand for 24 or 30 hours and at the end of this time is washed with distilled water until the wash water no longer reddens a blue piece of litmus paper, i.e., until every trace of hydrochloric acid has been removed from the bone coal. Wood charcoal may be treated in like manner. When this coal is perfectly dry it is employed in the same proportions as the other, 8 to 1,000, the operation being exactly the same.
He turns next to the clarification of the vinegar.
It happens everywhere that vinegar instead of being clear is sometimes turbid. This is due to particles of yeast dissolved in the vinegar that have not yet settled. To remove this kind of turbidity it is customary to use oak or beech shavings that have been washed in hot water and then dried. These shavings, which must be very long and extremely thin, are put in a barrel with a second and perforated bottom, to a depth of 12 to 34 inches. The vinegar that runs through them deposits its slimy constituents on the shavings and becomes perfectly clear, and presents to the eye a pleasing appearance.
To this generally known method I would add a few more:
1. I take a ½ kilo of well pulverizedanimal charcoal(black burned bones) to 7/8 of a hectoliter of vinegar (1 lb. to 20 gallons), and stir it well with a wooden rod; or, if the vinegar is in bottles, I shake it a long time after putting the animal charcoal in the bottle, and repeat it several times. After three or four days I finally filter the vinegar through linen, when the filtrate will exhibit the desired clearness.
2. The best way to clarify vinegar is withisinglass. It is first broken up, then swelled for a day in vinegar (17 or 18 grammes to the liter), then 2 liters of vinegar are added and the mass boiled until the isinglass is completely dissolved. Such a solution as this (½ ounce to 3 quarts) is mixed with 10¼ hectoliters (250 gallons) of turbid vinegar and well stirred through it. After the expiration of five or six weeks vinegar treated in this way has a beautifully clear appearance.
3.Albumencan likewise be used to clarify it. The vinegar is boiled with the albumen until the latter is completely coagulated, and then the vinegar is filtered.
4. And finallymilkmay be employed. For this purpose the milk is skimmed, and 1 quart of milk added for every 68 quarts of vinegar, the mixture well stirred and shaken. After the caseous portion has coagulated (curdled) it is filtered as before, and in this case, too, the product is a fine, clear vinegar.
We believe that these few experiments, so easily performed, and at so small an expense, will prove useful to our readers in enabling them to put their product in the market in an excellent condition and nicely clarified.
At a recent meeting of the Manchester section of the Society of Chemical Industry, Mr. Ivan Levinstein described the history and progress of the manufacture of alizarine, from which are produced fast red, purple, brown, and black dyes. He said alizarine was, until very recently, made only from the root of the madder plant, of which the yearly crop was 70,000 tons, and represented an annual value of £3,150,000, of which the United Kingdom consumed 23,000 tons, representing a value of nearly £1,000,000.
Madder is now no longer grown for this purpose. The German chemists found that alizarine produced from madder in undergoing certain treatment gave a substance identical with anthracine, one of the constituents of coal tar, and in 1869 the same chemists announced to the world that they had accomplished the synthesis of alizarine from anthracine. The effect of this discovery was to throw madder out of cultivation.
Mr. Perkin, an English chemist, and Messrs. Graebe and Liebermann, German chemists, almost simultaneously applied for patents in 1869, in England, and as their methods were nearly identical they arranged priorities by the exchanging of licenses. The German license became the property of the Badische Aniline Company, and the English license became the property of the predecessors of the North British Alizarine Company. These patents expire in about two months, and the lecturer explained that an attempt made by the German manufacturers to further monopolize this industry (even after the expiry of the patent) proved abortive. He also stated that alizarine, 20 per cent. quality, is sold to-day at 2s 6d. per lb., but that if the price were reduced by one-half there will still be a handsome profit to makers, and that the United Kingdom is the largest consumer, absorbing one-third of the entire production, and that England possesses advantages over all other countries for manufacturing alizarine--first, by having a splendid supply of the raw material, anthracine; secondly, cheaper caustic soda in England than in Germany by fully £4 per ton; thirdly, cheaper fuel; fourthly, large consumption at our own doors; and, fifthly, special facilities for exporting.
The advantages derived from the development of the alizarine manufacture here, it was stated, will benefit other collateral industries, such as manufacture of soda, of ordinary sulphuric acid, bichromatic, and chlorate of potash, articles used in this manufacture. The lecturer considered that the difficulties attending the manufacture of alizarine were now overcome, and with sufficient capital and competent chemists English manufacturers must be successful.
He then proceeded to explain the source from which nearly all the artificial coloring matters are derived, viz., gas tar; showing the principal products of this wonderful, complex mixture, of which one is anthracine. Alizarine manufacturers originally found scarcity of anthracine; at present the supply is in excess of the demand, and the price during the last 18 months has fallen from 3s. 6d. to 1s. per unit, and the probabilities are that the supply will increase. The quantity of gas tar now obtained the lecturer estimated at 500,000 tons per annum, and the coal carbonized for gas making, 10,000,000 tons. This quantity of tar suffices to produce 9,000 tons of 20 per cent. alizarine.
The lecturer then reviewed, in case of an increased demand for anthracine, the probable new sources of obtaining increased supplies of coal tar: (1) The destructive distillation of petroleum; (2) coke ovens and blast furnaces; (8) the carbonization of coal for general manufacturing purposes, using the coal and gas as fuel, and giving tar, benzine, and ammonia as residues; and (4) distillation of coal with the object of obtaining the principal products, tar and benzine, and as the residual product, gas. This part of the lecture was important to dyers and printers, the lecturer showing also, in a very interesting way, in what manner manufacturers may very considerably economize their consumption of coal.
The lecturer explained that while from one ton of coal there was obtained on an average about 17 oz. of benzine, by the new method about thirty times that amount can be got from the same quantity of coal. He also considered in great detail the different processes of the carbonization of coal, and of increasing the production of the different important residual products of gas tar, and also the best method of extracting the benzine. He showed samples of benzine which he produced from gas obtained at the Rochdale Road Gasworks, and, further, nitro-benzine, aniline, and coloring matters, which he had made from this gas benzine.
The lecturer also discussed the effect of the probable increased production of tar, ammonia, benzine, etc., as affecting gas companies, and said it was anticipated they either would raise the price of gas or change the present system of manufacture, which he considered probable. The enormous increase in the production of ammonia, of which the larger portion at present, as sulphate of ammonia, was used as a fertilizer, would no doubt considerably reduce its value. It might even replace soda for many purposes, and thus react on our alizarine industry.
He then proceeded to consider the manufacture of alizarine purpurine, and divided its manufacture into four stages: 1, the purification of crude anthracine; 2, the conversion of the purified anthracine into anthraquinone; and 3, the production of sulpho acid of anthraquinone and the conversion of this sulpho-acid into alizarine and purpurine. This part of the lecture comprised a detailed explanation of the various kinds of apparatus required, to be used which were beautifully got up, complete working models having been prepared for the occasion. The lecturer was of opinion that large consumers would be benefited if makers would offer for sale only three distinct coloring matters--iso or anthrapurpurine, and flavo-purpurine, leaving it to the dyers and printers to produce for themselves the intermediate shades by mixing the three colors; and he showed that by reason of the fastness of the shades produced by these coloring agents varying considerably, the blue shade (alizarine) being much faster then the orange shade (flavo-purpurine), consumers were in many instances losers by using mixtures of alizarine and flavo-purpurine.
In the course of the lecture many interesting specimens of various products were produced and dilated upon, the lecturer fully describing the process of purifying the crude anthracine and of the conversion of the purified anthracine into anthraquinone.