.COMMEECIAL PEODUCTION OF THYMOL FROM HORSEMINT. 5 



appears that a crop of 10,000 pounds will remove from one acre of 

 land the following quantities of nutrient materials: Nitrogen, as 

 ammonia, 38.5 pounds; phosphoric acid, as P2O5, 14.5 pounds; and 

 potash, as KjO, 59.5 pounds. The materials removed from the soil 

 could be replaced by the use of 800 pounds per acre of fertilizer hav- 

 ing the following composition: Nitrogen, as ammonia, 4.81 per cent; 

 phosphoric acid, as P2O5, 1.81 per cent; and potash, as KjO, 7.43 per 

 cent. 



Since some disposal must be made of the distilled herb it is probable 

 that this material if returned to the soil would restore most of the 

 nutrient materials removed and at the same time add vegetable 

 matter to the land. It is advisable, however, to compost this 

 material and to apply it to the field only after it is well decomposed. 

 The exhausted material has been found to contain an average of 50 

 per cent of water; and if proper allowance is made for the water 

 content a ton of this material would yield the following quantities of 

 nutrient materials: Nitrogen, as ammonia, 13.3 pounds; phosphoric 

 acid, as PjOg, 5.4 pounds; and potash, as K2O, 21.2 pounds. 



HARVESTING. 



In harvesting the crop excellent results were secured by the use 

 of a 1 -horse mowing machine, which was made adaptable for the 

 purpose by placing shoes under each end ol the cutting bar, so that 

 the plants were cut about 6 inches above the ground. As soon as 

 it is cut the herb should be gathered and hauled to the distilling 

 plant, since it has been foimd that by allowing the plants to dry in 

 the field there is considerable loss of oil. A large loss of leaves also 

 results, owing to their rapid drying and shattering off in handling. 

 Care must be taken in harvesting that the rooted layers about the 

 plant are not torn loose; otherwise, a large percentage of the plants 

 left in the field will die. The lower branches of the plant which 

 spring from the stems near its base grow downward and strike root 

 by natural layerage, and since in a large number of cases the old 

 root dies after the first year the plant is perpetuated by these layers. 

 In light soils these roots are easily torn loose and the death of the 

 plant results. On this account the use of a rake for getting up the 

 cut herb is undesirable, and forks should be used for that purpose. 



Considerable work, extending over a period of several years, has 

 been done in order to determine the proper time for harvestmg the 

 herb and also to ascertain the yield of oil and thymol at the different 

 stages of growth. In 1911, 16 tests were made with plants in the 

 budded stage and a like number with plants in full flower, to determine 

 the percentage of yield of oil and thymol in these two stages. The 

 average yield was as follows: In the budded stage, 0.36 per cent of 

 oil, with 64 per cent of total phenols; from the plants in full flower, 



