EFFECT OF CULTURE AND CLIMATE ON PEPPERMINT OIL. 



9 



Table V. — Comparison of the 'physical properties and the chemical composition of pepper- 

 mint oils distilled from the fresh leaves, from the tops, and from the entire fresh herb at 

 the various stages of growth. 



Year and descrip- 

 tion of material. 



1909. 



Budding stage: 

 Herb 



Leaves 



Tops 



Flowering stage: 

 Herb 



Leaves 



Tops 



Fruiting stage: 

 Herb 



Leaves 



Tops 



1910. 



Budding stage: 

 Herb 



Leaves 



Tops 



Flowering stage: 

 Herb 



Physical properties. 



Color, odor, and taste. 



Specific 

 gravity. 



Golden yellow; 

 pleasant, faint 

 odor; slightly 

 pungent, cooling 

 taste. 



Straw colored; frag- 

 rant but faint 

 minty odor; fatty, 

 pungent, slightly 

 bitter taste. 



Straw colored; very 

 fragrant minty 

 odor; fatty, bitter, 

 pungent taste. 



Pale yellow; agree- 

 able menthol-like 

 odor; pungent, 

 minty taste. 



Straw colored; pleas- 

 ant, minty odor; 

 pungent taste. 



Straw colored; flow- 

 ery odor; pungent 

 taste. 



Straw colored; very 

 flowery odor; 

 minty, pungent 

 taste. 



Golden yellow; 

 pleasant, minty 

 odor; minty. pun- 

 gent taste. 



Light straw colored; 

 pleasant, flowery 

 odor; minty, 

 slightly pungent 

 taste. 



Dark golden; not 

 fragrant, minty 

 odor; slightly bit- 

 ter, pungent, 

 minty taste. 



Golden yellow; faint, 

 not especially 

 minty odor; 

 slightly bitter, 

 pungent taste. 



Golden yellow; 

 agreeable, minty 

 odor; strong, pun- 

 gent, bitter, cool- 

 ing taste. 



Pale yellow; mild, 

 agreeable odor; 

 fatty, strong, cool- 

 ing, pungent taste 



Rota- 

 tion, 

 50 mm. 

 tube. 



a. 9143 



a . 9203 



a . 9389 

 a . 9370 



a . 9151 



a . 9223 



<7.9155 



9 . 9156 



9 . 9273 



-11 



-10.3 



- 8.3 

 -9.6 



- 9.5 



-12.1 



Refrac- 

 tion. 



61.4738 



61.4718 



61.4662 



61.4706 

 61. 4732 



61.4676 



61. 4730 



61.4723 



11.4718 



Solubil- 

 ity in 

 80 per 

 cent 



alcohol. 



Free 



acid 



(as 



acetic) 



Volumes. 



11.2 



11.2, 



11 



dl.5 



el 



A. 7 



ft. 6 



Chemical composition (per 

 cent). 



.32 



.03 



Ester 

 (men- 

 thyl 

 ace- 

 tate). 



7.07 



17.3 

 15.9 



12.37 



15.56 



16.62 



19.80 



13.44 



11.67 



Menthol. 



Free. Total 



30.1 

 37.7 

 31.8 



46.5 



41.7 

 37.75 



33.8 



37.58 



34.8 



43.76 

 18.79 

 29.19 



30.94 



38.76 



52.09 



55.38 

 50.29 



43.58 



53.18 



56.85 



34.39 



39.78 



40.13 



a At 22° C. 



6 At 25° C. 



c Clear in excess. 



d Turbid in 3 volumes or more. 



« Turbid in 1J volumes or more. 

 / Turbid in 2 volumes or more. 

 9 At 24° C. 

 ft Turbid in 4 volumes or more. 



