_Method of Extraction from the Stomach._--Use Stas-Otto process. _Test._--The contraction of the pupil which it causes. XL.--TOBACCO AND LOBELIA =Tobacco.=--_Nicotiana tabacum_ owes its poisonous properties to its alkaloid nicotine, a volatile, oily, amber-coloured liquid, with an acrid taste and ethereal odour; soluble in water, alcohol, ether, and chloroform. The drug has an intense depressant action on the heart and respiratory centre. _Symptoms._--Giddiness, fainting, nausea, and vomiting, with syncope, muscular tremors, stupor, stertorous breathing, and insensible pupil. Death has occurred after seventeen or eighteen pipes at a sitting. _Post-Mortem Appearances._--Not uniform or characteristic. General relaxed condition of muscles; engorgement of cerebral and pulmonary vessels. Congestion of gastric mucous membrane. _Treatment._--Emetics, stimulants, hypodermic injection of 1/25 grain of strychnine. Warmth to the surface by hot bottles, hot blankets. _Method of Extraction from the Stomach._--Digest the contents of the stomach in cold distilled water and _very dilute_ sulphuric acid; strain, filter, and press residue. Evaporate the filtrate to half its bulk, digest with alcohol, and evaporate alcohol off in a water-bath. Dissolve residue (sulphate of nicotine) in water, and make solution alkaline with potash; then shake with ether in a test-tube. Remove ether and allow it slowly to evaporate. Test resulting alkaloid. _Tests._--No change of colour with the mineral acids. White deposit with corrosive sublimate. Sulphuric acid and bichromate of potassium give a green colour, oxide of chromium. Precipitate with bichloride of platinum and with carbazotic acid. =Lobelia Inflata= (Indian Tobacco).--Much used in America by the Coffenite practitioners, and a valuable remedy for asthma. _Symptoms._--Nausea, vomiting, giddiness, cold sweats, prostration. Headache, giddiness, tremors, insensibility, and convulsions. XLI.--HYDROCYANIC ACID =Prussic Acid= is the most active of poisons. The diluted hydrocyanic acid of the Pharmacopoeia contains 2 per cent. of hydrocyanic acid, Scheele's 4 per cent. It is a colourless liquid, feebly acid, with odour of bitter almonds. =Cyanide of Potassium= is largely used in photography and in electro-plating, and is also poisonous. It often contains undecomposed carbonate of potassium, which may act as a corrosive poison and cause erosion of the mucous membranes of the lips, mouth, and stomach. =Oil of Bitter Almonds=, used as a flavouring agent, may contain (when improperly prepared) from 5 to 15 per cent. of the anhydrous acid.