It is polymerised by the action of strong sulphuric acid, the polymer, of course, boiling at a higher temperature than the original oil. With water it forms a crystalline hydrate (C₁₀H₂₀O₂,H₂O). On passing nitrosyl chloride gas into the oil, either pure or diluted with chloroform or alcohol, the mixture being cooled by ice, a white crystalline body is deposited, of the formula C₁₀H₁₆(NOCl). By treating this compound with alcoholic potash, the substitution product (C₁₀H₁₆NO) is obtained. By treating turpentine with an equal bulk of warm water, and shaking it in a large bottle with air, camphoric acid and peroxide of hydrogen are formed. When turpentine oil is left in contact with concentrated hydrochloric acid, there is formed terebenthene dihydrochloride (C₁₀H₁₆2HCl), which forms rhombic plates, insoluble in water, and decomposable by boiling alcoholic potash, with formation of terpinol, (C₁₀H₁₇)₂O. The dihydrochloride gives a colour-reaction with ferric chloride. This is an excellent test--not, it is true, confined to oil of turpentine--but common to the dihydrochlorides of all the terpenes. A few drops of the oil are stirred in a porcelain capsule with a drop of hydrochloric acid, and one of ferric chloride solution; on gently heating, there is produced first a rose colour, then a violet-red, and lastly a blue. § 152. =Effects of the Administration of Turpentine.=--L. W. Liersch[143] exposed animals to the vapour of turpentine, and found that a cat and a rabbit died within half an hour. There was observed uneasiness, reeling, want of power in the limbs (more especially in the hinder extremities), convulsions partial, or general, difficulty of respiration; and the heart’s action was quickened. Death took place, in part, from asphyxia, and in part was attributable to a direct action on the nervous centres. The autopsy showed congestion of the lungs, ecchymoses of the kidney, and much blood in the liver and spleen. Small doses of turpentine-vapour cause (according to Sir B. W. Richardson)[144] giddiness, deficient appetite, and anæmia. From half an ounce to an ounce is frequently prescribed in the country as a remedy for tape-worm; in smaller quantities it is found to be a useful medicine in a great variety of ailments. The larger doses produce a kind of intoxication with giddiness, followed often by purging and strangury, not unfrequently blood and albumen (or both) is found in the urine. When in medical practice I have given the oil, and seen it given by others, in large doses for tape-worm to adults, in perhaps 40 cases, but in no one instance were the symptoms severe; the slight intoxication subsided quickly, and in a few hours the patients recovered completely. Nevertheless it has been known to destroy the lives of children, and cause most serious