54 CITRUS LIMONUM 



General Characters and Composition. Oil of lemon as prepared, 

 either by the sponge or ecuelle process, is a limpid liquor, having 

 a slight yellow colour, a very fragrant odour like that of the fruit, 

 and a warm, bitterish, aromatic taste. Like the other oils 

 obtained from the genus Citrus, it is dextrogyre. It dissolves 

 but sparingly in rectified spirit, but readily in anhydrous alcohol. 

 It mixes freely with bisulphide of carbon. The distilled oil is 

 colourless, far less fragrant, and therefore less valuable as a per- 

 fume than the oil prepared as above, and is of less specific gravity. 

 The purified oil of lemon resembles oil of turpentine in composi- 

 tion and general chemical characters. Oil of lemon, as found in 

 commerce, is almost universally mixed with oil of turpentine, or 

 with the cheaper distilled oil. 



Medical Properties and Uses. Oil of lemon is a stimulant and 

 carminative when given internally, and stimulant and rubefacient 

 when applied externally. It has been used as a local application 

 in certain forms of ophthalmia, but with doubtful efficacy. It is 

 chiefly employed in medicine to communicate an agreeable odour 

 and flavour to other medicines. The chief use of oil of lemon is, 

 however, in perfumery, and as a flavouring agent in confectionery. 



3. LIMONIS Succus. Lemon Juice. Concentrated lemon juice 

 is imported in enormous quantities for citric acid manufacturers. 

 As thus imported it is not derived from the lemon only, but also 

 from the lime and bergamot. 



General Characters and Composition. The characters as given 

 in the British Pharmacopoeia are as follows : " A slightly turbid 

 yellowish liquor, possessing a sharp acid taste, and grateful odour. 

 Average specific gravity 1*039. Average quantity of citric acid in 

 one fluid ounce, 32*5 grains." According to Stoddart, however, 

 the specific gravity averages 1*044, and an average of 42*53 

 grains of citric acid in an ounce of juice. The amount of acid, 

 however, varies in different seasons, diminishing rapidly, as 

 proved by Stoddart, with the advance of summer. Its principal 

 constituents besides citric acid are gum, sugar, and, according to 

 Cossa, potash, although Stoddart found only a minute proportion 

 of this substance. Lemon juice readily undergoes decomposition, 



