Pharmacopceias. 89 



Rosemary Oil (Essenza di rosmarino). — Colourless or yellowish-green; d^o 0.90 

 to 0.92; soluble in 10 parts of 90 per cent, alcohol 1 ). 



x ) Rosemary oil dissolves already in one-half volume of 90 per cent, alcohol. 



Sandalwood Oil (Essenza di sandal o).— Move or less yellow; di 5 o 0.975 to 0.985 l ); 

 a D to the left 2 ); soluble in 5 parts of 70 per cent, alcohol; santalol (Ci 5 H 24 0) content 

 not below 90 per cent. 3 ). 



!) The lower limit should be 0.973. 



2 ) The angle of rotation lies between — 16 and — 20°. 



3 ) This minimum content does not agree with the statements given in the pharmacopoeia as to the 

 estimation of santalol which correspond to a content of 87.26 per cent. 



Terpine Hydrate (Terpina idrata). — Lustrous, colourless and odourless prisms; 

 on drying in a vacuum or above sulphuric acid it loses about 9.5 per cent, water; 

 soluble in about 250 parts of cold, in 32 parts of boiling water, or in 10 parts alcohol, 

 insoluble in light petroleum; the aqueous solution must show neutral reaction; terpine 

 hydrate melts at 116°, terpine at 102 01 ); on boiling the aqueous solution acidified with 

 sulphuric acid a smell of hyacinths 2 ) is produced; 0.1 g. terpine hydrate must burn 

 without leaving a residue. 



J ) Terpine melts at 104 to 105°. 



2 ) In this reaction, terpineol is formed which, however, smells of lilac and not of hyacinth. 



Thymol (Timolo). — Colourless, translucent crystals; m. p. 49 to 50 01 ); b. p. 228 

 to 230 ° 2 ); sparingly soluble in water (about 1:1200), the aqueous solution must show 

 neutral reaction; soluble in less than 1 part of alcohol, ether, acetic acid, chloroform, 

 and fatty oils; soluble in 2 parts of 10 per cent, caustic soda solution; melted thymol 

 floats on water, solid thymol drops down; 0.05 g. thymol, when heated on the water- 

 bath, must volatilize completely; identity tests and test for absence of phenol. 



1 ) The m. p. lies between 50.5 and 51.5°. 



2 ) Thymol boils, under 753 mm. pressure, at 232°, the mercury thread being fully surrounded by the vapours. 



Turpentine Oil (Essenza di trementina). — Colourless; boiling range, 155 to 162°; 

 diso 0.860 to 0.877; « D to the right or the left according to the origin of the oil 1 ); 

 perfectly volatile; hardly soluble in water, soluble in 12 parts 90 per cent, alcohol, 

 7 vols. 94 to 96 per cent, alcohol, in every proportion of absolute alcohol, ether, chloro- 

 form, carbon disulphide, fatty and essential oils 2 ); resinifies when exposed to the air; 

 neutral reaction; when kept in a bottle but partly filled the oil turns yellow and shows 

 acid reaction. 



For certain purposes, the crude oil is admitted, which is colourless or faintly 

 yellow and leaves on evaporation a residue of 2 per cent.' 5 ). 



In addition, old, so-called ozonised oil must be kept for use, which colours blue 

 a pa'ste of starch and potassium iodide. 



x ) The rotation ranges between + 41 ° and —35°. 



2 ) Possible turbidity is caused by a small amount of water in the oil owing to the distillation process. 

 On addition of a desiccating substance, e. </., sodium sulphate, such turbidities disappear instantaneously. 



*) This evaporation must be performed with special precautions, as otherwise too high values may result. 

 Compare Gildemeister and Hoffmann, The Volatile Oils, 2 nd ed., vol. II, p. 20. 





