804 UMBELLIFER^. 



Thymol is more conveniently and completely extracted from the 

 oil by shaking it repeatedly with caustic lye, and neutralizing the 

 latter. 



The oil of ajowan, from which the thymol has been removed, boils 

 at about 172°, and contains cymene (or cymol), C^^H" which, with con- 

 centrated sulphuric acid, affords cymen-sulphonic acid, C"'ff^SO"OH. 

 The latter is not very readily crystallizable, but forms crystallized salts 

 with baryum, calcium, zinc, lead, which are abundantly soluble in water. 

 In the oil of ajowan no constituent of the formula C'H^'' appears to be 

 present ; mixed with alcohol and nitric acid (see p. 279) it at least pro- 

 duces no crystals of terpin. 



The residual portions of the oil, from which the cymene has been 

 distilled, contains another substance of the phenol class difierent from 

 thymol. 



We have found that neither the thymol nor the liquid part of 

 ajowan oil possesses any rotatory power. 



Uses — Ajowan is much used by the natives of India as a condi- 

 ment.^ The distilled water which has been introduced into the Pharma- 

 copQiia of India, is reputed to be carminative, and a good vehicle for 

 nauseous medicines. It has a powerful burning taste, and would seem 

 to require dilution. The volatile oil may be used in the place of oil of 

 thyme, which it closely resembles. 



Ajowan seeds are largely imported into Europe since thymol has 

 been universally introduced into medical practice (see Folia Thymi). 

 The}^ have proved much more remunerative for the manufacture of 

 thymol than Thymus vulgaris. The largest quantities, we believe, of 

 thymol have been made from ajowan at Leipzig. 



Substitutes — Under the name Semen A'jumi, the very small fruits 

 of Ainmi niajus L. and of Siso7i Amoniwm L. have been often con- 

 founded with those of Ajowan ; but the absence of hairs on the two 

 former, not to mention some other differences, is sufficient to negative 

 any supposition of identity. 



The seeds of Hyoscyamus niger L. being called in India Khordsdni- 

 ajwdn, a confusion might arise between them and true ajowan ; though 

 the slightest examination would suffice to show the difference.^ 



FRUCTUS CARUI. 



Semen Carui vel Cai^i ; Caraway Fruits, Caraway Seeds, Caraways ; 

 F. Fruits ou Semences de Carvi ; G. Kv/mmel. 



Botanical Origin — Carum Carvi L., an erect annual or biennial 

 plant not unlike a carrot, growing in meadows and moist grassy land 

 over the northern and midland parts of Europe and Asia, but to what 

 extent truly wild cannot be always ascertained. 



It is much cultivated in Iceland, and is also apparently wild.^ It 

 grows throughout Scandinavia, in Finland, Arctic, Central, and 



^ Roxburgh, Flor. Ind. ii. (1832) 91. the seeds of henbane are "used in food as 



2 To such a mistake may probably be re- carminative and stimulant " ! 



ferred the statement of Irvine (Jccou?i< o/ ^ Babington in Journ. of Linn. Soc, 



the Mat. Med. of Patna, 1848, p. 0) that Bot. xi. (1871) 310. 



