— 104 — 



cyanate, on the other hand, gave rise to an «-naphthylurethane, m. p. 81 

 to 82° (from dil. methylalcohol). i) 



We are at present engaged in preparing the alcohol synthetically, and 

 in identifying it by preparing a few of the esters. 



A new colour-reaction has been recommended for distinguishing 

 Japanese peppermint oil from peppermint oils of other origin 1 ). We will 

 content ourselves with placing the matter on record here because we only 

 employ tests of this kind in exceptional cases, seeing that they lack all 

 scientific foundation, and fail, moreover, in the case of mixtures. The 

 author heats 1 cc. of the oil with 0,5 gram of a mixture of equal parts 

 paraformaldehyde and citric acid over a water bath. With Japanese 

 peppermint oil there is no decoloration, whereas with American, English, 

 Italian (and as our tests show with Saxon oils also), a purple colour 

 develops. This new test has the advantage of being quicker than the 

 familiar colour reaction with concentrated acetic acid. 



On the presence of d-neomenthol in Japanese peppermint oil see p. 180. 



Peppermint Oil, Russian. A few years ago 2 ) we reported on a 

 peppermint oil which came from the Province of Tambov, in Central Russia. 

 Recently, according to a statement by Maisit 3 ) the cultivation of peppermint 

 has also been taken up in the Caucasus, where the climate is more 

 favourable, and where the plant is said to flourish so well that South Russian 

 peppermint oil has been for some time a commercial article in the Russian 

 home market. In the District of Sotshi, situated on the Black Sea, the 

 black variety of English peppermint (Mentha piperita, Mitcham var. nigra), 

 is chiefly cultivated. It is grown at an altitude of about 1500 feet and is 

 distilled in newly-erected, modern distilling plant. According to the growers* 

 statements the dried herb of the flowering pliant yields from 1,6 to l,7°/o 

 of crude oil. 



Oil from 



d20O 



«D 



Acid 

 v. 



Ester 

 Menthol 



Free 

 Menthol 



Total 

 Menthol 



First year's plants 



0,912 



— 17° 42' 



0,57 



6,57 % 



42,44 % 



49,17% 



Second year's plants 



0,913 



— 17°57' 



0,57 



8,74% 



41,33°/o 



50,07% 



Both oils were sparingly soluble in 70% alcohol, and when placed in 

 a freezing mixture menthol began to separate out only after prolonged 

 standing. 



!) Perfum. and Essent. Oil Record 2 (1911), 275. 



2 ) Report April 1907, 82. 



3 ) Arch, der Pharm. 249 (1911), 637. 



