UNITED STATES DEPARTMENT OF AGRICULTURE 



, „ BULLETIN No. 372 



lit "^ 



""■sar^ /W^F^ Contribution from the Bureau of Plant Industry "w^^ ,^ ^^ ^_^ 



J^lv'^^U WM. A. TAYLOR, Chief ^?^'^>J'U 



Washington, D. C. 



May 16, 1916 



COMMERCIAL PRODUCTION OF THYMOL FROM 

 HORSEMINT (MONARDA PUNCTATA), 



By S. C. Hood, 

 Scientific Assistant, Drug-Plant and Poisonous-Plant Investigations. 



CONTENTS. 



Introduction - - - 1 



Cultural methods for horsemint - . 3 



Planting the seed 3 



Soils 3 



Cultivation and fertilizers 4 



Harvesting 5 



Distillation 6 



Extraction of the thymol 8 



Yield per acre 10 



Commercial prospects 10 



INTRODUCTION. 



It has long been known that thymol is present in considerable 

 quantity in the oil distilled from horsemint (Monarda punctata), 

 but so far as the writer had been able to learn no attempt has been 

 made to cultivate this plant for the commercial production of thymol, 

 In 1907 horsemint was observed to occur in abundance as a common 

 weed on the sandy lands of central Florida, and the prehminary 

 examinations of the oil from the wild plants which were made at 

 that time seemed to indicate that a promising commercial source of 

 thymol could be developed by bringing this plant under cultivation 

 and selecting for propagation types of plants best suited for oil pro-- 

 duction. 



The leaf area of the wild plants is rather small, and the herb when 

 harvested consists mainly of woody stems which yield little or no 

 oil. The fresh entire herb gathered in Putnam and Volusia Counties, 

 Fla., yielded froni 0.12 to 0.20 per cent of oil, although in some 

 samples the yield fell far below these figures, owing to the excessive 

 proportion of stems. The content of total phenols in these oils 

 ranged from 56 to 62 per cent, and it was found that the phenols 

 consisted almost entirely of thymol. 



38116°— Bull. 372—16 



