Calcium salts, with alkalies and their carbonates, oxalates, and sulphates.

Calomel, with alkalies, alkaline chlorides, antipyrin, bromides, hydrocyanic acid, iodides, organic acids, soap, and sodium carbonate.

Chloralamide, with alkalies.

Chloral hydrate, with alcohol, alkalies, calomel, carbolic acid, and potassium iodide.

Chlorates, with black antimony, ferrous iodide, hypophosphites, mineral acids, sulphur, and many organic compounds (dry and wet), tannin, and tartaric acid.

Chlorine, with alkalies, bromides, iodides, lead and silver salts, tannin, vegetable mucilages, extracts, waters, infusions, tinctures and syrups, milk, and emulsions.

Cocaine and its salts, with alkalies, borax, and other alkaloidal precipitants.

Cochineal is precipitated by salts of zinc, bismuth, and nickel as a lilac powder; iron gives a dark purple, tin a brilliant scarlet, and alumina the lakes.

Codeine salts, with fixed alkalies and other alkaloidal precipitants, except ammonia.

Collodion, with water or aqueous fluids.

Copper sulphate, with alkalies and their carbonates, iodides, and vegetable astringents.

Creosote, with silver oxide and other oxidisers.

Dermatol, with acids.

Digitalis preparations, with alkalies, cinchona preparations, iodides, iron salts, and lead acetate.

Diuretin, with acids and alkalies.

Europhen, with metallic oxides, mercury salts, and starch in presence of fats.

Exalgine behaves like antipyrin.

Formaldehyde, with ammonia, bisulphites, mercuric chloride, and generally it acts as a reducing agent.

Hexamine, with acids, acid salts, and quinin. et ferri cit.

Homatropine salts, with alkalies, mercuric chloride, and other al-kaloidal reagents.

Hydrogen peroxide, with oxidisable substances and lime-water.

Hyoscyamine and hyoscine salts, similar to homatropine salts.

Hypophosphites, with mercuric chloride ; generally act as reducing agents, greedily absorbing oxygen, and explode when rubbed with oxidisers, such as chlorates and nitrates. (A mixture of equal parts of sodium hypophosphite and nitrate has exploded violently.)

Hyposulphites, with mineral acids and soluble salts of the heavy metals.

Ichthyol, with acids.

Inf. rosae acidum, with alkalies, borax, and liq. plumbi subacet. Iodine, with acacia gum, alkalies, alkaloids, metallic salts, essential oils (sometimes explosive), and fixed oils (partly absorbed).

Iron, reduced, with extracts (if acid) and metallic and alkaloidal salts.

Iron salts, with acacia mucilage (persalts), alkalies, alkaline carbonates, vegetable infusions and extracts (astringent), gallic acid, and tannin.

Iodoform, with calomel.

Kino preparations, with alkalies, gelatin, mineral acids, and metallic salts.

Lead acetate, with acids, albumen, alkalies, carbonates, chlorides, chromates, citrates, iodides, phosphates, soap, sulphates, tannin, and tartrates.

Lead subacetate, same as the last, also with acacia mucilage.

Magnesium sulphate, with alkalies, lead acetate, potassium and sodium carbonates, and tartarated soda.

Mercuric chloride, with albumen, alkalies, alkaloids, hypophosphites, lead and silver salts, methylene blue, potassium iodide, reduced iron, soap, sulphurous acid, tannin, and vegetable infusions.

Mercuric oxide, with chlorides.

Mercury iodides, with alkalies.

Mercury subchloride (see Calomel). Morphine salts, with alkalies, tannin, vegetable infusions, and the usual alkaloidal precipitates.

Nitrites, with acid solutions. See Spt. AEther. Nit.

Nux vomica preparations, with alkaloidal precipitants ; and note that nitric acid changes colour of mixtures.

Opium, with alkaline carbonates, chlorine-water, iodine, liq. arseni-calis, salts of copper, iron, lead, mercury, and zinc, and tannin.

Pepsin is precipitated by alcohol (above 25 per cent.) and ammonium and magnesium sulphates or any salt which saturates the mixture.

Phenocoll salts, with alkalies and their carbonates.

Physostigmine salts, apart from usual alkaloidal incompatibles, become red with ammonia owing to formation of rubeserine.

Pilocarpine hydrochloride, with alkalies, iodine, mercuric chloride, and silver nitrate.

Potash, sulphurated, with acids, carbonated waters, and zinc sulphate.

Potassium bromide (see Bromides).

Potassium chlorate (see Chlorates). Should never be rubbed with sulphur or any combustible compound, nor should strong sulphuric acid be poured over it.

Potassium cyanide, with acids, morphine salts, and silver nitrate.

Potassium iodide, with tr. ferri perchlor. and lead, mercury, and silver salts.

Potassium nitrate, with most sulphates.

Potassium permanganate, with glycerin, alcohol, and other oxidis-able substances. Solutions should not come in contact with cork.

Quinine salts (dissolved), with alkalies, carbonates, tannin, and vegetable infusions.

Resorcin, with ammonia and other reagents.

Saccharin, with potassium iodide.

Salicylates (alkaline), with acids, some alkaloids, ferric salts, and spt. aether, nit.

Salol, with alkalies.

Silver nitrate, with tap-water, hydrochloric, sulphuric, acetic, and tartaric acids and their salts, hydrocyanic acid and its compounds, iodine, iodides and bromides, alkaline and earthy carbonates, sulphur, arsenites, arsenical solutions, tannin and astringent infusions, essential oils, extracts, and resins.

Silver oxide, with acids, ammonia, bromides, chlorides, creosote, iodides, and tannin.

Sodium arsenate, with syr. ferri iodidi.

Sodium nitrite, with weak acids, ammonium bromide, oxidising agents, and vegetable extracts.

Spt. atheris nitrosi, with water, alkalies, emulsions, ferrous sulphate, gallic and tannic acids, and bromides and iodides.

Strontium salts, with phosphoric and sulphuric acids and their salts.

Strychnine solutions, with alkalies, astringents, and liq. arsenicalis.

Sulphocarbolates, with ferric salts.

Syr. pruni virg., with alkaloids. Valerianates, with acids.

Zinc chloride, with hard water.

Zinc permanganate explodes when mixed with alcohol, extracts, glycerin, and sugar.

Zinc valerianate, with acids, soluble carbonates, tannin, and metallic salts.