OLEUM BERGAMOTTiE. 123 



extraction it gradually deposits a quantity of white greasy matter 

 (bergaptene), which, after having been exhausted as much as possible 

 by pressure, is finally subjected to distillation with water in order to 



separate the essential oil it still contains. 



The fruits from which the essence has been extracted are submitted 

 to pressure, and the juice, which is much inferior in acidity to lemon 

 juice, is concentrated and sold for the manufacture of citric acid. 

 Finally, the residue from which both essence and juice have been 

 removed, is consumed as food by oxen. 



Description ^ — Essential oil of bergamot is a thin and mobile fluid 

 of peculiar and very f ragnant odour, bitterish taste, and slightly acid 

 reaction. It has a pale greenish yellow tint, due to traces of chloro- 

 phyll, as maybe shown by the spectroscope. Its sp. gr. is 0'86 to 0'88; 

 its boiling point varies from 183^ to 195° C. 



The oil is miscible with spirit of wine (O'SS sp. gr.), absolute alcohol, 

 as well as with crystallizable acetic acid. Four parts dissolve clearly 

 one part of bisulphide of carbon, but the solution becomes turbid if a 

 larger proportion of the latter is added. Bisulphide of carbon itself 

 is incapable of dissolving, clearly any appreciable quantity of the oil. 

 A mixture of 10 drops of the oil, 50 drops of bisulphide of carbon and 

 one of strong sulphuric acid has an interise yellow hue. Perchloride of 

 iron imparts to bergamot oil dissolved in alcohol a dingy brown 

 colour. 



Panuccio's oil of bergamot examined in the same way as that of 

 lemon (p. 120) deviates 7" to the right, and has therefore a dextrogyre 

 power very inferior to that of other oils of the same class.2 But it 

 probably varies in this respect, for commercial specimens which we 

 i^idged to be of good quality deviated from 6'8° to 104° to the right. 



If essential oil of bergjamot is submitted 



omp 



to rectification, the portions that successively distill over do not accord 

 in rotatory power or in boiling point, a fact which proves it to be a 

 niixture of several oils, as is further confirmed by analysis. It appears 

 to consist of hydrocarbons, O'W, and their hydrates, neither of which 

 have as yet been satisfactorily isolated. Oil of bergamot, like that of 

 turpentine, yields crystals of the composition C'B}' + SH^O, if 8 parts 

 are allowed to stand some weeks with 1 part of spirit of wine, 2 of 

 ™c acid (sp. gr. 1-2) and 10 of water, the mixture being frequently 

 shaken. No solid compound is produced by saturating the od with 

 anhydrous hydrochloric gas. 



ihe greasy matter that is deposited from oil of bergamot soon after 

 Its extraction, and in small quantity is often noticeable in that of 

 commerce, is called Bergaptene or Bergamot Camphor. We have ob- 

 tained It in fine, white, acicular crystals, neutral and inodorous, by 



- . vviucii n\ our opinion requires luruier mvcouij^nu^wx.. ^^j^^.^^ 

 oergaptene is abundantly soluble in chloroform, ether, or 



Ewenc^ ^.^-^^■a'^ters are taken from some at Keggio and also large cultivators of the 



'l5Mal ic-n'"^''^'^"^ i^^'^^^^^^^^i^^ooneofua bergamot orange. ^ _ 



G Pan • '^' ^^ a type-sample by Messrs. ^ See however Okum ^ troli, p. 1-/ ■ 

 uccioefigli, manufacturers of essences 



