dyeing, 82 pounds of alizarine, 4 gal- | 4.67 per cent. of castor-oil, 43.90 per lons of blood, and, according to the cent. of ricinoleic acid, and 3.685 per quality of the water, 12 ounces of tannin cent. of ash. Such oil is prepared by a and chalk are used for 88 pounds of complete saponification of castor-oil yarn. After the yarn is dyed it is with caustic soda. The resulting soap brightened for 10 hours in the high- is decomposed with diluted acid. The pressure boiler with 25 pounds of cal- separated fatty acids are removed by cined soda; then acidulated with 3 water and then compounded with a like pounds of tin salt, 1 pound of nitric quantity of water and a sufficient acid, and 8 ounces of alum; next amount of caustic soda, that about of soaped with 22 pounds of soap, 5 the castor-oil used is again saponified. pounds of soda, 2 pounds of tin salt, 113 After boiling the mixture it is allowed ounces of nitric acid, and 1 pound of to cool and is then converted into an annotto, and finally washed, oiled, emulsion by stirring. loaded, and soaked. To Prepare the so-called Turkey-red Oil. The following process furnishes a Turkey-red oil which, when dissolved in water, gives a clear fluid well adapted for dyeing and printing with alizarine. Add in a thin stream and with constant stirring 1 pounds of sulphuric acid of 66° Beaume to 6 pounds of castor-oil. Heating during the process should be carefully avoided, but should it occur, the adding of sulphuric acid must be interrupted until the mass has entirely cooled off. The greater the quantity worked at one time the greater is the danger of heating and the consequent spoiling of the product. If the work is carried on on a large scale it is best to use vats lined with lead. The mixing of the sulphuric acid with the oil requires from 2 to 4 hours; 3 hours suffice for the above-mentioned quantity. The mass is now allowed to stand quietly for 12 hours, when it is diluted with 1 gallon of water. Calcined soda in small portions is now added until litmus paper is no longer colored red. About 11⁄2 pounds of pure soda will be required. This operation must be carried on very slowly, as, on account of the escape of carbonic acid, a strong foaming will take place. The mass gives now a white emulsion with water. To obtain a clear solution ammonia is added until a sample gives a clear solution with water. It is then allowed to settle for about 12 hours, when the now finished Turkey-red oil is drawn off by means of a siphon. The sodium sulphate which has been formed by the re-neutralization will be found as a crystallized residue on the bottom of the vessel. English Alizarinoil (Patent Oil) is composed of 48.69 per cent. of water, A New Dye. The young shoots of the poplar tree yield a dye which can be extracted as follows: The young twigs and branches are bruised and boiled for 20 minutes with a solution of alum-10 pounds of wood requiring 1 pound of alum-in 34 gallons of water. The solution is filtered hot and allowed to cool, and after standing some time is again filtered from a resinous deposit. On exposure to air and light it develops a rich gold color and may be used directly for dyeing orange and yellow shades upon all classes of goods. ELECTRO-PLATING, GALVANOPLASTY, The double sul Nickel Plating. phate of nickel and ammonium, which is the salt that is generally used, may now be had in commerce almost pure. The anodes should considerably exceed in size the articles to be covered with nickel. Any common form of battery may be used. Three Daniell's cells, or two Bunsen's, connected for intensity, will be found to be sufficient. The battery power must not be too strong, or the deposited nickel will be black. A strong solution of the sulphate is made, and placed in any suitable vessel; a glazed stoneware pot answers very well if the articles to be covered are small. Across the top of this are placed two heavy copper wires, to one of which the articles to be covered are suspended, to the other the anode. The wire leading from the zinc of the battery must then be connected with the wire from which the articles are suspended, the other battery-wire being connected with the anode. To prepare the articles for coating, they must be well cleansed by scrubbing them, immersing in boiling potash, to remove any grease, then dipping them for an instant in muriatic acid, and afterwards washing thoroughly in water, taking care that the hand does not come in contact with any part of them. This is accomplished by fastening a flexible copper wire around them and handling them by means of it. The wire serves afterwards to suspend them in the bath. If the articles are made of iron or steel, they may be first covered with a thin coat of copper. This is best done by the cyanide bath, which is prepared by dissolving precipitated oxide of copper in cyanide of potassium. A copper plate is used as an anode. After they are removed from the copper bath, they must be washed quickly with water and placed in the nickel bath. If allowed to become dry, or to tarnish, the nickel will not adhere. must be observed during the whole proGreat care cess to keep all grease, dust, or other dirt from the articles to be coated, or else the result will be unsatisfactory; The whole process is one of the most difficult that is used in the arts, it being far easier to gild, plate, or copper an article than to nickel it; but if due care is taken the results will amply pay for the trouble. Improvement in Nickel Plating. E. Weston, of Newark, N. J., has found that an addition of boracic acid adapts the different salts of nickel better for electrolytic separation than any other substance, and especially prevents the formation of sub-salts of nickel on the cathode. The following mixtures can be especially recommended: Five parts of nickel chloride and 2 of boracic acid; or 2 of nickel sulphate and 1 of boracic acid. The nickel precipitated from these solutions adheres very tenaciously. process gradually saturated with freshly preThe bath is heated to 175° F., and cipitated nickel hydrate. It is then removed from the fire, saturated with gallon of ammonia, and diluted with water to a bulk of 5 gallons. It is now allowed to become cold. One pound of ammonium carbonate is then added, the fluid is allowed to settle, and is finally filtered. A white layer of nickel of great density ing. The double salts of nickel and ounce to 14 ounces to the gallon, according to the nature of the solution. Instead of benzoic acid one of its salts, for instance benzoate of nickel, may advantageously employed for solutions be used, and such addition may also be of cobalt and other metals. The inventor recommends the following proportions for a bath of 1 gallon : Nickel sulphate Sheet metal plated by this can be polished, stamped, and fashioned Benzoic acid into various shapes without injury to the coating. Martin and Delamotte's Process of Nickel Plating. Prepare a bath of: Water Citric acid I. II. Nickel chloride Nickel citrate Nickel acetate 3.3 gallons. Nickel phosphate 234 pounds. As benzoic acid is difficult to dissolve in water it is best to heat the nickel salts in a sufficient quantity of water, and to add the benzoic acid during the boiling. It will thus dissolve much easier with the nickel salts than in pure water The great advantage of these solutions is that the manufacturer is no longer restricted to the use of certain chemically pure salts. For preparing the acetate, citrate, and sulphate of nickel, respectively, the ordinary acids of commerce can be used, as the injurious influences of the impurities, always present in these salts or acids, are entirely neutralized by the benzoic acid. These solutions are also adapted for electrotyping purposes, where the metal is deposited upon surfaces rendered conductive by a thin coating of graphite, bronze powder, etc. The deposit, as soon as the desired thickness has been obtained, can also be detached in the same manner from the surface or the metal. In case the solutions to be used contain alkaline salts, it is best to prevent a possible incomplete decomposition of the fluid by an addition of sodium pyrophosphate. Finally salicylic, gallic, or pyrogallic acid may be substituted for a part or the whole of benzoic acid. Receipts for Ordinary Nickel Baths. I. Boil, with constant stirring, for hour, 1 pound of the double sulphate of nickel and ammonium and pound of hydrochlorate of ammonia in 1 gallons of water, and let the fluid cool over night. II. Boil for hour 1 pound of the double sulphate of nickel and ammonium and 1 ounces of citric acid in 2 gallons of water. Then allow it to cool and add from to ounces of carbonate of ammonia in small pieces until the fluid is neutralized. III. Boil for hour 10 ounces of the double sulphate of nickel and ammonium, a like quantity of sulphate of ammonia, and 1 gallons of water, and let the fluid cool. IV. Dissolve 10 ounces of the double sulphate of nickel and ammonium by boiling in 34 quarts of water, and allow the fluid to cool. The solution is neutralized with spirit of sal-ammoniac, and diluted with water, until it is concentrated to 20° to 25° B. V. Dissolve 2 pounds of the double sulphate of nickel and ammonium, 14 pounds of hydrochlorate of ammonia by boiling in 83 gallons of water, and make the fluid slightly alkaline so that it shows 3° to 4° by the hydrometer, by adding 34 pounds of caustic ammonia. VI. Dissolve 1 pound of the double sulphate of nickel and ammonium, 104 ounces of hydrochlorate of ammonium, and 7 ounces of sulphate of ammonium by boiling in 1 gallons of water, and allow the fluid to cool. American Nickelling. The following baths are in use in a number of large American manufactories: I. Bath for Iron, Cast-iron, and Steel. Dissolve 2 pounds of the double sulphate of nickel and ammonium and 54 ounces of sulphate of ammonia by boiling in 54 gallons of water. II. Bath for Brass, Copper, Tin, Britannia Metal, Lead, Zinc, and Tinned Sheet Metal. Dissolve 2 pounds of the double sulphate of nickel and ammonium and 7 ounces of sulphate of ammonium by boiling in 64 gallons of water, and let the fluid cool. In case any acid should still be present a little hydrochlorate of ammonia must be added, so that red or blue litmus paper remains unchanged. Latest Anglo-American Nickelling. The best nickel-plating, for the excellence of which we can vouch, is accomplished by using the following bath: Two pounds of the double sulphate of nickel and ammonium and 1 pound of refined boracic acid are boiled for hour, when the fluid is allowed to cool. This bath gives a silverwhite plating, and all parts of the article receive a uniform nickelling and remain unchanged even if con tinuously used, which is not the case with other nickel baths. In nickelling large articles, several nickel anodes must be suspended on each of the four sides. In nickelling plates, cups, etc., a plate of nickel must be suspended in the centre of the hollow, but should be, if possible, kept at a distance of 2 to 4 inches from the article to be nickelled. A strong Bunsen battery of 4 to 8 elements, or, what is still better, a dynamo-electric machine, is used. Preparation of the Metals to be Nickelled. The treatment of iron and steel requires no further explanation. We advise to first immerse the articles for some time in a boiling hot solution of caustic soda or potash, next to rub them thoroughly with a brush, then to rinse with cold water, and finally to dip them into an acid pickle consisting of 1 part of sulphuric acid and 2 of hydrochloric acid to 10 of water, after which they are again rinsed, thoroughly rubbed with fine, washed pumice-stone or Vienna lime, rinsed off, and at once brought into the bath. Fine polished instruments of iron and steel for surgical, dental, and other purposes, scissors, knives, and telegraphic instruments are treated in the same manner, but in place of the washed pumice-stone they should be brushed with whiting or tripoli, or, what is still better, with infusorial earth. Brass, bronze, Britannia metal, etc., are also treated with a hot solution of caustic soda or potash, then rubbed and brushed, rinsed with water, and at once placed in a solution of cyanide of potassium. They are then cleansed with a bristle brush kept for that purpose, carefully rinsed in water, and at once brought into the bath. The variegated colors produced upon brass by the action of the solution of caustic soda disappear almost instantaneously in the solution of cyanide, and a bright surface of the metal is sure to be obtained. Special attention must be paid to the careful rinsing of the articles, especially if they have hollow places and depressions, after they have been treated in the solution of cyanide of potassium, to prevent the nickelling bath from being contaminated by the cyanide. For many articles of brass having more or less matt and polished places, it is sufficient to dip them (after having been freed from all fatty substances by boiling potash and subsequently rinsing in water) into the mixture of acids, then to rinse them again, and to bring them at once into the bath. For iron articles the use of finely sifted pumice-stone or chalk is absolutely necessary. Copper wire should be tightly wound around all articles of metal, and two or more wires around large articles. In articles consisting of two metals, for instance iron with steel or with brass, the wire must be wound around both metals. Smaller articles are suspended from copper hooks. The articles should not be immersed in the nickelling bath until the battery or machine is in action. The suspended articles remain in the bath until they have acquired a white color, which, according to the strength of the electric current and the number and size of the articles suspended, will require from 5 to 30 minutes. Large articles of steel or iron require longer than brass, copper, etc., and, if they fill the entire bath, must remain in it, according to circumstances, for several hours or an entire night. In case the article to be nickelled assumes a gray or black color, or feels gritty or rough, the current is too strong. The article, after its removal from the bath, should immediately be dipped for a few seconds in boiling hot water, then allowed to drain off, dried in warm sawdust free from rosin, and, if necessary, polished. Fine articles are rubbed with a polishing brush or with soft leather and whiting. Polishing the articles with a burnishing steel after they have been nickelled is not admissible, as the coating is too hard and brittle for such usage. The better they have been polished before plating, the more beautiful will be the nickelling. To Nickel Iron without the Use of Electricity. To a solution of chloride of zinc 5 to 10 per cent. strong add enough nickel salt to give the usual color of nickel baths. Cleanse the articles and put them in the solution for to 1 hour. Doumesnil's Process of Platinizing Metal. The precipitate obtained by treating a solution of platinum chloride with sal-ammoniac is intimately mixed with finely pulverized borate of lead by adding water. The articles, which should and 3 ounces of sodium phosphate to the boiling point, and add, while this is boiling, the thoroughly shaken solution above described. Continue to boil the mixture until the fluid has become entirely clear and the odor of ammonia entirely disappears, and the solution, at first alkaline, ceases to impart a blue color to reddened litmus paper. When this bath is cold and has been filtered it is ready for use. It requires a strong, constant current and a large anode. According to Jewreinoff, copper and brass can be electroplated with platinum to any desired thickness by taking the articles from time to time from the solution of platinum and scouring them with whiting. The salt of platinum used is prepared in the following manner: One hundred parts of potassium hydrate dissolved in water are added to a solution in water of the chloride of platinum obtained from 100 parts of metallic platinum. The minute yellow crystals of platino-chloride of potassium which are formed are heated with 20 parts of oxalic acid in a porcelain vessel until they disappear, and, when the solution is complete, 300 parts more of potassium hydrate, dissolved in water, are added. first be thoroughly cleansed, are coated with this mixture and then subjected to a strong heat in a sheet-iron muffle. Platinizing of Metals. Optical instruments, etc., are platinized by boiling them in a solution of ounce of ammonio-chloride of platinum and 3 ounces of sal-ammoniac in 14 ounces of water. This solution may also be used for copper and brass articles. Platinum plating is a subject about which very little has been said or written, as electro-platers who have actually obtained good results have kept the process a profound secret. We give below receipts received from acknowledged authorities and from private sources. There are two methods of platinum plating: by dipping without the use of a battery (boiling), and by electrolysis. Copper and its alloys are best adapted for platinizing, as the platinum adheres well to them, but not very well to iron, zinc, tin, and lead. The following solution is recommended for platinizing by boiling: One part of pure chloride of platinum in solid form and as neutral as possible and 10 of entirely pure sodium hydrate are separately dissolved, each in 50 parts of water, and the platinum solution is then carefully poured into the sodium lye. When the two solutions have been thoroughly mixed add ammonia until the mixture shows a perceptible odor of it. The bath is heated to the boiling point, the articles, which should first be thoroughly cleansed, are dipped into it, and, as soon as they have acquired a white, brilliant coating, rinsed in hot water, Plating with Aluminium. Dissolve dried in sawdust, and, if necessary, any desired quantity of salt of aluminagain dipped. This coating, no matter ium, such as the sulphate, muriate, how well it may look, will necessarily nitrate, acetate, cyanide, etc., in distilled be very thin and not capable of resist- water, and concentrate the solution to ing acids, scouring, etc. Electroplating 20° Beaumé in a suitable vessel to hold is necessary for most purposes. A the articles to be plated. The battery skilled and experienced operator, by to be used should be 3 pairs of Bunsen's accurately observing the following di-zinco-carbon, with the elements conrections, can obtain_a_deposit of any desired thickness and showing the same lustre as pure platinum: Dissolve 10 drachms of pure chloride of platinum in 7 ounces of water. Then dissolve 13 ounces of ammonium phosphate in 7 ounces of water. Mix this with the solution of platinum, disregarding the precipitate which is formed. In the meanwhile bring 10 ounces of water To Electroplate Metals with Cobalt. The same formulæ as have been described under nickel plating will be found to answer also for cobalt by simply substituting cobalt salts for those of nickel where these are named. The deposit is even more brilliant than that of nickel. (W.) nected for intensity, and an anode of aluminium attached to the negative wire. The solution should be slightly acidulated with its appropriate acid, heated to 140° F. and kept at that temperature during the operation. Gilding Copper by Boiling. Take a liquid amalgam consisting of 4 parts of mercury, 2 of zinc, and 1 of gold. Mix this amalgam with 8 parts of hydro |