Spots

Every recipe is a starting point for experiment, not a guarantee

Hiscox warns that chemicals vary in purity, heat and cold change results, and clumsy handling spoils batches, so he prints several near-identical formulas under each heading for the reader to choose among. The first practical entry blackens a laboratory table top: hot coats of copper sulphate and potassium chlorate, then aniline hydrochlorate, darkening to ebony over hours under linseed oil. Stone cements follow, such as sulphur and rosin melted with litharge and ground glass, or pitch, wax and brickdust.

PREFACE → Cements For Metals and For Attaching Various…

Metal joints, can labels and photographs each need a different glue

Cast-iron cements mix iron filings with sal ammoniac and sulphur, made into a paste with water or strong vinegar only at the moment of use. Can labels take a flour paste no thicker than maple syrup, so it soaks through and the label rubs flat. Photographic mounts must be neither acid nor alkaline, which is why rice starch and gum dragon are preferred. The alloy section opens with aluminium blends, measuring the density and brittleness of each mixture.

Lutes. → Bronzes.

Shift the copper-zinc ratio and brass changes colour predictably

A table runs brass from 84 per cent copper, reddish yellow, down to 66 per cent, pale yellow. French bronze sits at 91.6 copper, while Japanese bronzes carry heavy lead because it improves the patina. Copper-manganese-aluminium alloys studied by Gumlich became strongly magnetic, one gaining strength after 544 hours at 230°F and suffering permanent injury at 329°F. Type metals balance lead, antimony and tin, and bearings divide between hard red brass and softer white metal.

Cadmium Alloys: → Applications Of Strontium Amalgams.

Mercury makes cheap zinc behave like pure zinc in batteries

Amalgamating a zinc plate, by dipping it in dilute sulphuric acid and brushing on quicksilver, stops impurities from forming tiny wasteful cells inside the metal. Cadmium amalgams were plugging teeth. Silver-chloride cells, dry-battery pastes of charcoal, graphite and manganese dioxide, and a trick of adding cane sugar to sal ammoniac solution to keep a crust of basic zinc salt from choking the rods all follow. The stretch ends at the soda counter with hot chocolate and egg chocolate.

Applications Of Cadmium Amalgams. → Winter Beverages

Acid in the varnish turns bronze powder to verdigris

Soda-fountain drinks come first: pineapple champagne, tea beer fermented with yeast, limejuice cordial kept with boric acid, and an imitation champagne built on crab-apple cider and brandy. Bronze powders are coloured by heating brass dust in iron pans until the oxide reaches the right shade. For liquid gold, dammar rosin must first be washed with caustic soda to strip its acids. Smelly bicycle-lamp carbide is tamed with petroleum, and naphthalene cast with camphor makes moth tablets.

Beer: → Tasteless Castor Oil.—

Hold it to the light: porcelain glows, pottery does not

Castor oil loses its taste after being shaken with hot water and scented with wintergreen and saccharine, or after being warmed over roasted coffee and bone black. Pottery bodies follow by name: jasper, Egyptian black, ironstone, cream and sage, with glazes tinted from a white base by cobalt, red lead and enamel colours. Boiling new china for four hours is said to stop it cracking. Cheese, finally, is casein curdled by rennet from a calf's stomach.

How To Take Castor Oil. → Imitation Cider.—

Butter, pipe clay and magnesia lift stains harsher cleaners would damage

Imitation cider ferments honey, catechu, alum and yeast for about two weeks before whiskey, almond oil and caramel are added, while a cheaper version uses tartaric acid and brown sugar. Cleaning methods target each surface: Javelle water then hyposulphite for marble, turpentine and pipe clay for paint on sandstone, butter left for hours on oily leather, and benzine with burnt magnesia for greasy glass and mirrors. A flour, acid and chloride-of-lime paste cleans varnish without harming it.

CIGARS → Flavoring Spices.

Freckle bleaches work by acid, so go slowly

Mustard comes from three plants: white seed for mild, black for pungent, and Brassica juncea for the oily Russian kind, with heat able to destroy the bite entirely. Its pressed oil is mild and greenish enough to pass cheap oils off as Lucca olive oil. Rouges are built from zinc oxide, bismuth subnitrate and carmine. Freckles yield to lactic acid, glycerine and rose water or diluted peroxide, but never to corrosive sublimate, and never on freshly sunburned skin.

Mustard: → Sunburn And Freckle Remedies.

Soap, scented oils and carbolic acid clean mouths, skin and drains

Liver-spot lotions use zinc sulphocarbolate, borax or quince-seed mucilage in rose water. Mouthwashes dissolve white castile soap in alcohol with peppermint, wintergreen, cassia and cloves, and an eau de Botot imitation warns that oil of cedar wood smells of cedar while oil of cedar tops smells of turpentine. Disinfecting fluids combine rosin, creosote and pitch, and sanitary powders mix alum, eucalyptus, ultramarine and salt or slaked lime with carbolic acid.

Liver Spots. → Purple And Violet Dyes

A mordant fixes the colour; the dyestuff only supplies it

Wool is boiled for two hours in alum, tartar and tin salts before madder is brought from 120°F to 200°F, and camwood reds are darkened with blue vitriol and copperas. Archil gives lilac silk, and lac dye a scarlet. Embalming fluids follow, with the warning that success depends on clearing the circulation first, and mixtures of zinc chloride, mercuric chloride, arsenic or formaldehyde. Enamel is melted in a plugged crucible and run into water.

Red, Crimson, And Pink Dyes: → Fusible Enamel Colors.

Lead acetate exposes aniline dye hiding in fruit syrup

Purple of Cassius is gold in aqua regia precipitated by tin, then fluxed with borax, red lead and flint and blended into rose, ruby and maroon enamels. Food colours come from cochineal and carmine. Lead diacetate precipitates natural colouring but leaves aniline dyes in solution, so a cloudy filtrate is honest, and salicylic preservative betrays itself with iron chloride. A survey of explosives notes that smokeless powders rest on nitrated cellulose, made slower burning than gun cotton.

Preparation Of Enamels. → Artificial Fertilizers For Pot Plants.

Nitrogen grows leaves; drop it when flowers are wanted

Pot-plant feeds dissolve ammonium nitrate, potassium phosphate and magnesium sulphate at a few parts per thousand, with one formula noting that leaving out the ammonium nitrate shifts plants from foliage to bloom. Household adulteration tests follow: the Halphen test turns cottonseed oil red, though its carbon bisulphide is flammable and best mixed by a druggist. Candling shows a fresh egg as evenly translucent with a clear air cell. Chilblain remedies range from carbolic ointments to camphor-iodine pencils.

Preparing Bone For Fertilizer. → Colored Glass.

A burning string and cold water can cut glass cleanly

A string soaked in alcohol is tied around the glass, burned off, the glass plunged underwater, and a sharp tap breaks it along the line. Bulbs are tinted with water glass or gelatin carrying aniline colour, softened with glycerine against cracking, and selenium turns glass rose or, with cadmium sulphide, orange-red. Hair washes use rosemary, lanolin and birch-bud oil. Honey is clarified with charcoal, chalk and egg white, and a hectograph is renewed by burning alcohol across its surface.

Coloring Electric-light Bulbs And Globes.

Liquids follow bugs into cracks where powders never reach

The best gold ink is gold leaf ground in honey, washed and suspended in weak gum water, while chemically precipitated gold is finer but comes out brown. Zinc garden labels take copper-sulphate or platinum-chloride writing that lasts as long as the metal. Bedbugs fall to kerosene with pennyroyal or eucalyptus because a liquid reaches the eggs. Flies take quassia paper, said to be harmless to people, or sticky rosin and honey, and ivory softens in phosphoric acid.

Gold Ink. → Lac And The Art Of Lacquering.

Mix a red and a yellow lacquer to dial any gold

Aluminium is lacquered with gum lac in ammonia and baked near 572°F, and brass with seed lac tinted by annatto, saffron and turmeric. Bronze lacquer is made as two stocks, a dark red of shellac, lake and dragon's blood and a yellow of gamboge, blended to any shade from deep red to gold. Russia leather swells in fermented rye and oat flour, tans in willow, poplar and pine barks, and is curried with birch and seal oil.

Lacquer For Aluminum. → Coloring Metals

Alcohol vapour can close the cracks in an old painting

A dark, cracked oil painting held face down over a dish of alcohol softens until its fissures close, though it must be watched constantly or the colours run. Copper reddens in potassium ferrocyanide and blues in liver of sulphur. A melting-point table runs from tin at 551°F through copper at 1,931°F to platinum at 3,225°F, with mercury freezing at 38° below zero. Dry paints are compounded from ochre, whiting and zinc, and carbolineum preserves wood.

Fusion Point Of Metals. → Waterproof Papers.

One three-part developer, diluted differently, serves plates, tanks and paper

Waxed paper is made by rubbing beeswax over paper on a hot plate, and paper dipped in zinc oxide dissolved in caustic soda keeps wrapped silver from blackening. Paper must be sized with isinglass or parchment before varnishing. A tolidol developer is kept as three stock solutions, mixed one-one-one with seven water for plates, much weaker for tank work, and stronger for paper, alongside pyrocatechin formulas. Lantern-slide mats should be clean cut and modest.

Metallic Paper. → Toning Baths For Paper.

Grit in a pigment announces itself as a scratch

Prints are fixed in acidified hyposulphite, then toned blue or brown with uranium nitrate and red prussiate of potash. A blueprint bleached orange in caustic soda turns brown in tannic acid. Pigment is tested for grit by shaking it in a tube so heavier or lighter particles separate, then rubbing samples between glass plates, where impurities scratch audibly and leave marks a microscope can read. Nobili's coloured rings are drawn on metal by electrolysis from a platinum point.

Combined Toning And Fixing Baths. → Gilding And Gold Plating

Mask the metal, and gold deposits only on the design

Parts to be gilded are painted with white lead, the rest coated in asphalt varnish, and the white lead washed off before electroplating. A benzol bath then dissolves the asphalt and leaves a gold design. Ivory is gilded by painting gold chloride and holding it over hydrogen, and mat gilding needs sand-blasting first. Polishing covers vinegar for copper, sulphuric acid in alcohol for nickel spots, and Vienna lime for tin, and fruit juice is preserved by heating bottles in water.

Oxidizing Processes: → Pyrotechnic Magic.

Mineral springs can be bottled as a spoonful of salts

Parlour fire tricks include bowls of water that seem to ignite thanks to a hidden reactive metal, with a warning that they are safe only in specially flanged bowls, plus a blazing banana and sparks blown from the fingertips. Kissingen and Vichy waters are rebuilt from sodium chloride, magnesium sulphate and bicarbonate. Epsom salt is traced through its many names to the springs of Epsom. Smelling salts scent ammonium carbonate with violet and orris, and shoe whitening uses pipe clay.

RAT POISONS → Coloring Soap.

Solder must melt below its work and match its colour

Garment soap blends shaved soap, ammonia and benzine into a paste rubbed into grease spots and rinsed after half an hour. Dr. Sarg's glycerine soap must be free of alkali. German-silver solders vary copper, zinc and nickel, the hardest needing a blowpipe, while gold solder becomes more fusible as the gold being joined gets stronger and is tinted with silver and copper. Potatoes are about a fifth starch, and badly stored ones can reach 5 per cent sugar.

Garment-cleaning Soap. → Coloring Steel

Controlled rust, scrubbed back twice, gives a gun its brown

The United States Ordnance Manual browning mix of iron tincture, corrosive sublimate, sweet spirits of niter, blue vitriol and nitric acid is sponged onto a cleaned barrel and left 24 hours. The rust is scratch-brushed, the treatment repeated, and the barrel boiled and oiled. Fountain syrup is best kept as a heavy stock of 15 pounds of sugar per gallon and diluted to about 6, and foamed syrups should never be bought. Tin powder is shaken in a chalked box.

Tempering Steel. → Rules For Varnishing.

Turpentine beats every other solvent for asphalt varnish

Varnish that crawls is fixed by first wiping the surface with sharp vinegar or diluted ox gall. Amber for coach varnish is bleached white with rock salt and remelted. For asphalt, ether dries under the brush, chloroform costs too much, petroleum stays tacky and smelly, and benzine dries too fast, so water-white turpentine that evaporates without stain wins. Veterinary formulas follow for hide bound, influenza, udder inflammation and horse liniments, with sulphur named the specific for mange.

Preventing Varnish From Crawling. → Waterproofing Fabrics.

Three leather waterproofings trade days of soaking for hours

Tenning saturates leather in a hot zinc soap over about 48 hours, and Prideaux rubs in caoutchouc dissolved in turpentine for several days. Villon applies a soap-and-glue solution followed by salt and alum, finishing in four or five hours. Cordials are flavoured with caraway, peppermint and fennel, and orange wine ferments pressed oranges with sugar. Piano veneer demands caution in polishing, and white spots on wood are lifted through blotting paper with a hot iron.

Waterproofing Paper. → Yeast Tests.

Book

Henley's Twentieth Century Formulas, Recipes and Processes

A working sense of how early-1900s workshops and homes mixed cements, alloys, dyes, inks, drinks and polishes.

@spots #chemistry #recipes #crafts #history
Read Henley's Twentieth Century… in full
Discuss
See more like this