CULTIVATION AND PREPARATION OF PYRETHRUM. 167 



seed to burst prematurely and rot, where slower absorption in a soil 

 only tolerably moist affords the best conditions for germination. 



The seed of both species sown, whether in the fall of 1880 or in the 

 spring of 1881, germinated tolerably well, though some was evidently 

 worthless when received. A few plants of roseum from that sown in 

 the fall of 1880, bloomed the ensuing autumn, while all sown in the 

 spring of 1881 bloomed profusely the following summer. 



B-oth species withstood the winters very well, and as these were ex- 

 treme winters, the one very severe and cold, the other open and mild, 

 the test may be considered a very thorough one. The older leaves died 

 off, as is the custom with many allied perennial species, but the plants 

 began growing very early in spring and were, in fact, among the vernal 

 adornments of the garden. Boseiim began blooming early in May, and 

 showed every variation in color from almost pure white to deep crimson. 

 It also showed considerable variation in the green of the leaves as well 

 as in the form, some plants having the leaves much more fiuely cut than 

 others. Cineraricefolium which has a much smaller flower, with pure 

 white petals, very strongly resembling the common Ox-eye Daisy, began 

 blooming a month after roseum had passed its prime. It proved uniform 

 in color, and is always distinguishable from roseum, even before bloom- 

 ing, by the whitish or glaucous green of the leaf, and its much deeper 

 and broader incisions. 



A portion of the flower heads were dried and pulverized, the powder 

 proving to be fully equal in efficacy to the imported article j while the 

 powder from dried stems and leaves is decidedly weaker, but still useful 

 when applied in large quantities.^^ 



Preparation op the plants for use. — In regard to manufactur- 

 ing the powder, the flower heads should be gathered during fine weather, 

 when they are about to open, or at the time when fertilization takes 

 place, as the essential oil that gives the insecticide qualities reaches, at 

 this time, its greatest development. AVhen the blossoming has ceased 

 the stalks may be cut within about four inches from the ground and util- 

 ized, being ground and mixed with the flowers in the proportion of one- 

 third of their weight. Great care must be taken not to expose the flow- 

 ers to moisture, or the rays of the sun, or still less to artificial heat. 

 They should be dried under cover and hermetically closed up in sacks 

 or other vessels to prevent untimely pulverization. The fiuer the flower 

 heads are pulverized the more effectually the powder acts and the more 

 economical is its use. Proper pulverization in large quantities is best 

 done by those who make a business of it and have special mill facihties 

 Lehn & Fink, of IS'ew York, have furnished us with the most satisfac- 

 tory powder. For his own use the farmer can pulverize smaller quan- 

 tities by the simple method of pounding the flowers in a mortar. It is 

 necessary that the mortar be closed, and a piece of leather through 

 which the pestle moves, such as is generally used in palveriziiig phar- 

 maceutic substances in a laboratory, will answer. The quantit}^ to be 



