EFFECT OF CULTURE AND CLIMATE ON PEPPERMINT OIL. 3 



from the plants grown at Glenn Dale, Md., and Arlington Farm, Va„, 

 since these are but a few miles apart and the general climatic con- 

 ditions are practically the same in both localities. • 



Table I. — Comparison of yields and physical composition of peppermint oils distilled 

 from plants grown in several localities on various types of soils. 





Yield, 

 of oil. 



Physical properties. 



Chemical composition (per 

 cent). 



Locality and soil. 



Color, odor, and 



Spe- 

 cific 



Rota- 

 tion, 



Re- 

 frac- 

 tion. 



Solubil- 

 ity in 80 



Free 

 acid • 



Free 

 esters 

 (men- 



Menthol. 













taste. 



grav- 



50 mm. 



per cent 



(as 



thyl 













ity. 



tube. 



alcohol. 



acetic). 



ace- 



Free. 



Total. 



















tate). 









P.ct. 







o 





Volumes. 











Arlington Farm, 



0.12 



Pale yellow; 



<*0.9203 



-10.6 



61.4662 



cl.2 



0.21 



7.07 



46.5 



51.7 



Va. (heavy clay 





agreeable men- 



















soil). 





thol-like odor. 



















Do 



.13 



Pale yellow; 

 mild, agree- 



a. 9273 



— 5.7 



a 1.4820 



d .6 



.03 



11.67 



30.94 



40.13 



























able, niinty 























odor; fatty, 























cooling, pun- 

 gent taste. 

 Pale straw; 



















Webster, S. Dak. 



.10 



a. 9280 



- 8 



& 1.4715 



dl.5 



.05 



9.9 



46.48 



54. 2S; 



(rich black 





pleasant flow- 



















loam). 





ery odor; pun- 

 gent, mmty, 

 cooling taste. 









* 











Glenn Dale, Md. 



.11 



Pale yellow; 



a. 9403 



-10 



el.4735 



d.& 



.75 



23.34 



35.89 



54.28 



(light sandy 





agreeable aro- 



















soil). 





matic, minty 

 odor; bitter, 

 slightly pun- 

 gent, cooling 

 taste. 



















a At 22° C. 

 b At 25° C. 

 c Turbid in 2 volumes Or more. 



d Turbid in 2J volumes or more. 

 e At 23° C. 



YIELD OF OIL FROM FRESH AND FROM DRY PLANTS AT VARIOUS 



STAGES OF GROWTH. 



In order to study the effect of the time of harvest upon the yield 

 and quality of peppermint oil and also the yield of oil as obtained 

 from fresh and dry plants, experiments were conducted through a 

 series of years, from- 1908 to 1912, inclusive. The plants were har- 

 vested at three distinct stages of growth, namely, the budding, flow- 

 ering, and fruiting stages, and the oil was distilled from both the 

 fresh and the dried plants. A comparison was made of the various 

 oils, the results being shown in Table II. 



The yield of oils distilled from the fresh plants during the budding 

 stage shows considerable variation, the yield in 1908 being especially 

 high. During 1909, 1910, 1911, and 1912 considerably less variation 

 is observed. Similar deviation during the flowering stage is to be 

 noted, the yield in 1908 again being noticeably higher. More uni- 

 formity is apparent in the results obtained from the fruiting plant. 

 In two of the seasons mentioned (1909 and 1911) the yield of oil 

 during the fruiting stage was slightly in excess of that from either 

 the budding or the flowering stage. 



