OIL OF BERGAMOTTE. 893 



being taken out, washed with ether, and re-dissolved in alcohol, 

 furnish the pure resin by spontaneous evaporation ; the salt of 

 copahuvic acid and ammonia loses its ammonia during the eva- 

 poration. The copahuvates of potash and soda are soluble in 

 water, that of ammonia soluble in ether and alcohol, but not in 

 water. The salt of silver is crystallizable. 



Oil of pepper, from Piper nigrum, has the same composition 

 as oil of copaiva, and is similar in properties. 



Oil of cubebs, from Piper cubeba, is supposed by Soubeiran 

 and Capitaine to be C 15 H 12 , its compound with hydrochloric 

 acid being C 15 H 13 C1. The former is still a multiple of C 5 H 4 . 



Oil of st or ax, from the balsam storax liquida, by distillation, 

 has, according to Marchand, its carbon and hydrogen as C 2 H, 

 or in the same relation as benzole, and therefore differs in com- 

 position from all other known essential oils. It is converted by 

 nitric acid into a resinous body, which yields a particular crys- 

 tallizable oil, by distillation, the nitrostyrole of Simon. 



Oil ofelemi, obtained by distilling the resin, is a transparent 

 colourless liquid, of an agreeable smell, its density is 0.852 at 

 75.2 (24 centig.) ; it absorbs hydrochloric acid, but does not 

 seem to form a solid camphor. It consists of carbon and hy- 

 drogen in the proportion of C 4 H 5 . (Stenhouse.) 



Laurel- turpentine oil, imported of late from Demerara under 

 the name of laurel oil; its density is 0.86*45 at 60, it begins to 

 boil at 301, but its boiling point rises to 325. Its smell 

 slightly resembles that of oil of turpentine, but is much more 

 agreeable and approaches that of oil of lemons. It contains no 

 oxygen, and consists of two or more isomeric oils of the C 5 H 4 

 type. This oil is an excellent solvent of caoutchouc, and is 

 employed as an external application in rheumatism. (Sten- 

 house.) 



B. ESSENTIAL OILS CONTAINING OXYGEN. 



Oil of bergamotte is obtained from the ripe fruit of the Citrus 

 bergamotta, or Citrus limetta (the lime). It is yellowish, but 

 when rectified, colourless, has an agreeable odour, and is much 

 used as a perfume. Its density is 0.862 ; it combines with 

 hydrochloric acid. It was found by Ohme to contain 7-098 



