DILL. 135 



tion of the alcohol, the solubility of carveiie increases rapidly in a 

 disproportionate degree. 



Both carvol and carvene are strongly dextrogyre, the latter 

 remarkably so. 



Carvol is identical with the carvol of Dill, but rather more 

 strongly dextrogyre and can only be recognised by its optical 

 power from the carvol of spearmint, which is hevogyre.* 



Oil of caraway also contains Garvacrol C^q H^, H, isomeric 

 with tliymol and very nearly related to it. It can be separated by 

 treating oil of caraway with potash,i- or by treating the same with 

 iodine, cohobating several times and washing the product with 

 potash ; as then obtained, however, it is mixed with carvene. 



Carvacrol can be obtained by heatins; a mixture of 50 grams, of 

 carvol, 50 grams, of cumin oil and 12 grams, glacial phosphoric 

 acid to boiling point for three or four hours ; then pouring off the 

 thick liquid and isolating the carvacrol by fractional distillation. 

 It is also formed by melting sulphonic acid with caustic potash 

 and is found among the products of the action of iodine on 

 camphor. Carvacrol is the principal constituent of oil of 

 Origanum liirtum (erroneously called " Spanish Hops,") and occurs 

 largely in oil of Satureja liortensis (" Pepper- wort."J 



Carvacrol, when pure, is a colourless viscid liquid lighter than 

 water and soluble in water to a certain extent. Its odour is by 

 some people considered very acrid, unpleasant and persistent ; by 

 others it has been considered analogous to that of Eussia leather, 

 — the very faint similarity is very distant — even when much 

 diluted ; but in any case it is very powerful and persistent. 

 Carvacrol boils at 232^ C, giving off vapours which irritate the 

 organs of respiration. It burns with a bright and very smoky 

 flame. 



Dill. 



This peculiar name is probably derived from the ancient Xorse 

 word Dilla,^ in allusion to the carminative properties of the drug; 



* Further investic^ations into the nature of carvol and its derivatives have 

 been made by Wallich and quite recently by Baeyer (Ber. Dentsch. Chem. 

 Ges., xxvi., p. 820). 



t Zeitschr, f. Chem. [2J iv., p. 730. 



X Prior, " Popular names of British Plants, 1870. 



