24 MISCELLANEOUS PAPERS. 



and leaving the stems almost bare, is apt to follow if very moist 

 weather occurs toward the latter part of the season. Weeds are 

 especially to be avoided in a mint field, since, as stated, the quality 

 of the oil will be seriously impaired if these are harvested with the 

 peppermint. The weeds generally found in a peppermint field are 

 Canada fleabane (Leptilon canadense), fireweed (Erechtites hieraci- 

 folia), giant ragweed {Ambrosia trifida), pennyroyal (Hedeoma 

 pulegioides) , Eaton's grass (Eatonia pennsylvanica) , June grass 

 (Poa pratensis), and other low grasses. 



HARVESTING AND DISTILLATION. 



The first crop of mint is harvested in the latter part of August, 

 when the plants are in full flower, and the gathering continues until 

 about the middle of September, the stills running night and day 

 until all the mint is disposed of. The first crop is usually cut with a 

 scythe, as mowing machines do not work well on soft cultivated land. 

 The succeeding crops are cut with a mowing machine or sweep-rake 

 reaper. The highest yield per acre and the best quality of oil are 

 obtained from the first year's crop. Sometimes, if the weather con- 

 ditions have been very favorable, a second cutting is made. The 

 yield of oil from peppermint obtained from the same field sometimes 

 varies very much, the condition of the atmosphere seeming to exert 

 an influence upon it, as it is said that mint cut after a warm and 

 humid night will yield more oil than that cut after a cool and dry 

 night. It requires about 330 pounds of dried peppermint to produce 

 1 pound of oil, and the yield of oil from an acre ranges from 12 to 50 

 pounds. 



If the mint crop has been grown on muck land, all that is necessary 

 after the crop has been harvested is to plow up the land and turn the 

 runners under for a new crop. If grown on upland, after the second 

 year's crop is in, or, at the most, after the third year's harvest, the land 

 is plowed and then given up to other crops. Peppermint exhausts 

 the land, and it is necessary to practice rotation of crops for about five 

 years in order to put the land in condition if it is desired to use it 

 again for peppermint cultivation. 



After the plants are cut they are usually placed in windrows until 

 they are dried, but are not allowed to become so dry as to permit the 

 leaves to shatter off, and are then taken to the distillery. Some grow- 

 ers believe that if the plants are allowed to dry there will be a smaller 

 oil content owing to the escape of some of the oil into the atmosphere, 

 and so have the plants brought to the distillery in the green state; 

 but Mr. A. M. Todd a is of the opinion that no loss of oil will result 



oAmer. Jour. Pharm., 60: 328-332 (1888). 



