Pyrethrum. 79 



this industry was G. N. Milco, a native of Dalruatia, who 

 successfully cultivated Pyrethrum cineraricefolium near Stock- 

 ton, Cal. The powder which he made has been sold under 

 the name " Buhach." It is in every respect apparently as 

 good as the imported article, and is even superior to the latter in 

 regard to strength. It is probably the best form to use in this 

 country. Plants of both species were grown in Washington, 

 D.C., in 1881, with satisfactory results. In the spring of that 

 year Riley distributed seeds of the two forms to growers in 

 various parts of the country. In this way the plants have 

 become fairly well known, and the use of the powder has rapidly 

 increased. On account of the cost, it has been used principally 

 in dwellings and in greenhouses. It is most frequently applied 

 in the dry form, but during the past few years it has given 

 good results either when mixed with water, or when the essen- 

 tial oil has been applied after being extracted by alcohol ; an 

 infusion of the entire flowers is also effective. 



It is difficult to say when kerosene oil began to be valued 

 for the destruction of insects. The oil was undoubtedly used 

 before any records of its insecticidal value were published ; 

 and one might suppose, from its nature, that it would possess 

 energetic properties of this character. Turpentine mixed with 

 earth and water was successfully used to destroy worms on trees 

 as early as 1835, 1 and it is but a step to pass from this liquid to 

 the use of kerosene. The latter was recommended for the de- 

 struction of scale on orange trees in 1865, 2 and was also 

 successfully applied to oleander, sago-palm, acacia, and lemon 

 trees. The oil was poured into a saucer and applied by means 

 of a feather. In June of the following year, the Gardener's 

 Monthly recommended this oil for destroying all insect life ; but 

 in an issue of the next month, the statement was modified by 

 saying that the vegetable oils were safer. 8 Many others proba- 

 bly had the same experience, for if not applied very carefully, 

 much injury to the foliage may result. It has been the practice, 

 both in Europe and this country, to apply kerosene with a 

 certain amount of water, having one part of oil to twenty-five 



1 The Cultivator, 1S35, 176, cites M. D. Thosse in Sittiman's Journal. 

 * Gardener's Monthly, 1865, Dec. 364. 

 Ibid. 1866, June, 176, and July, 208. 



