Scientific and other notes on essential oils. 



37 



Table II. 



Physical and chemical properties of oils taken from 



of development 



and dry herb in its various stages 



Stage of develop- 

 ment 



acid 1 ) | ester 2 ) 

 content 

 percent. I percent. 



Menthol 



free j total 



per cent. : per cent. 



budding 

 flowering 

 fruiting . 



budding 

 flowering 

 fruiting . 



A. Oil from fresh plants. 



0.912 at 23° to 

 0.9158 at 22° 



0.9203 at 22o to 

 0.9273 at 24° 



0.9151 at 22° to 

 0.9250 at 24° 



— 18.4 to 

 — 31.6° 



-9 to 

 -21.2° 



1.4696 at 24° to 

 1.4738 at 25o 



1.4662 at 25° to 

 1.4820 at 22° 



— 14 to 1.4676 at 25° to 

 — 42° 1.4712 at 22° 



B. Oil from dry plants. 



to 



0.86 



to 

 0.21 



to 

 1.14 



6.72 to 

 16.62 



7.07 to 

 14.5 



12.37 to 

 24.4 



30.1 to 

 43.76 



23.97 to 

 46.5 



12.7 to 

 34.33 



35.39 

 56.85 



35.39 

 52.09 



29.14 

 53.55 



0.9167 at 24° and 

 0.9337 at 21° 



— 22 and 

 — 26.2° 



1.4695 at 25° and 

 1.4724 at 22° 



0.17 and 

 1.20 



13.26 and 

 19.80 



36.07 and 

 39.41 



46.38 and 

 55.01 



0.9163 at 22° 



— 27° 



1 .4695 at 25° and 

 1.4765 at 22° 



0.16 and 

 3.20 



12.73 and 

 30.41 



37.37 



47.44 



0.9344 at 22° and 

 0.9383 at 24° 



— 6.6 and 

 - 16.2° 



1.4713 at 22° and 

 1.4718 at 25° 



0.36 and 

 0.56 



17.68 and 

 20.51 



34.2 



48.15 



Table III. 



Physical and chemical properties of the oils obtained from various parts of fresh plants. 











acid 1 ) ester 2 ) 



Menthol 



Oil from 



d 



«D 



"d 



content 

 percent. | percent. 



free 1 total 

 percent. | percent. 



Whole plant 

 Leaves . . . 

 Tops .... 



Whole plant 

 Leaves . . . 

 Tops .... 



Whole plant 

 Leaves . . . 

 Tops .... 



0.9155 at 24° and 

 0.9158 at 22o 



0.9143 at 22° and 

 0.9156 at 24° 



0.9151 at 22° 



0.9203 at 22° and 

 0.9273 at 24° 



0.9231 at 24° and 

 0.9389 at 22° 



0.9242 at 24° and 

 0.9370 at 22° 



0.9151 at 22° and 

 0.9250 at 24° 



0.9373 at 22° 



0.9223 at 22° 



A. Plant budding. 



-18.4 and 



— 24.2° 



-24.2 and 



— 26.2° 



— 24° 



1.4718 at 22° and 

 1.4738 at 259 



1.4710 at 22° and 

 1.4713 at 25° 



1.4718 at 25° 



B. Plant flowering. 



11.4 and 

 -21.2° 



18.8 and 



— 22° 



-13 and 



- 20.6° 



1.4662 at 25° and 

 « 1.4820 at 22° 



1.4706 at 25° and 

 1.4753 at 22° 



1.4732 at 25° and 

 1.4780 at 22° 



C. Plant fruiting. 



— 14 and 

 -16.6° 



— 19.2° 



— 19° 



1.4676 at 25° and 

 1.4712 at 22° 



1 .4730 at 25° and 

 1 .4720 at 22° 



1 .4723 at 25° and 

 1 .4738 at 22° 



0.1 and 

 0.86 



0.014 and 

 0.9 



0.116 and 

 0.13 



0.03 and 

 0.21 



0.52 and 

 1.90 



0.48 and 

 1.43 



0.10 and 

 1.14 



0.32 and 

 4.8 



0.16 and 

 3.30 



6.72 and 

 16.62 



9.9 and 

 19.80 



8.84 and 

 13.44 



7.07 and 

 11.67 



17.3 and 

 22.27 



15.9 and 

 22.98 



12.37 and 

 20.86 



1-9.8 and 

 43.40 



15.56 and 

 28.29 



30.1 and 35.39 and 

 43.76 56.85 



18.79 and 

 37.7 



29.19 and 

 31.8 



34.39 and 

 45.67 



38.76 and 

 39.78 



30.94 and 40.13 and 

 46.5 52.09 



37.83 and ; 55.38 and 

 41.7 ; 55.38 



37.75 and j 50.29 and 

 48.60 66.71 



12.7 and I 29.14 and 

 33.8 j 43.58 



37.58 



34.8 



53.18 



47.08 



menthol and of menthyl acetate seems to be restricted principally to the stalk ends. 

 Table II gives information concerning the qualities of the oils from dry and fresh plants 

 during the various stages of vegetation, whereas table III refers to the qualities of the 

 oils produced from the different parts of the plant. 



l ) Calculated as free acetic acid. 



2 ) Calculated as menthyl acetate. 



