SMUDGES AND FUMIGANT8. 31 



folium, and the crop in Dalmatia is comparatively as valuable as the 

 other. Thirty year- ago it was considered the most valuable export 

 in Dalmatia. The best powders are made from the dried flower- 

 heads of these plant-, and the essential principle seems to be a vola- 

 tile oil that disappears with age and with i Powder- im- 

 ported from Europe are apparently not »ng a- powders D 

 in this country from imported dried flowerheads brought over in 

 bulk. For this reason it was, many years ago, deemed very desira- 

 ble to establish a Pyrethrum-growing industry in the United Sti 

 and in 1881 the United States Entomological Commission imported 

 and distributed the seeds of the two species above mentioned to a 

 number of correspondents in- different parts of the country. The 

 total success was inconsiderable. Further experiments another year 

 met with comparative failure. About this time more extensive 

 plantations were made in California and an insect powder was made 

 by the Buhach Producing and Manufacturing Company, of Stockton, 

 Cal., which, being American grown and freshly ground, came into use, 

 and is still being produced and -old under the proprietary name of 

 " buhach." the word being supposedly derived from a Slavonic word 

 "buha," meaning flea. An article by Mr. D. W. Coquillett on the 

 production and manufacture of this powder will be found in a bul- 

 letin a of this Bureau. 



Most of the inject powders sold in the shops in this country have Pyre- 

 thrum powder as a basis. It i- difficult to get a pure and thoroughly 

 efficient powder. There is often adulteration. Frequently the powder 

 made from the dried flowerheads is adulterated with powder made 

 from the stems, or with other adulterants. Pyrethrum powder- are 

 usually used dry and are puffed or blown into crevices frequented 

 by insects, or pulled or blown into the air of a room in which there 

 are mosquitoes or Hie-. The burning of the powder in a room at 

 night is a common practice. The powder is heaped up in a little 

 pyramid which is lighted at the top and burns -lowly, giving off a 

 dense and pungent smoke with an odor very much like that of the 

 Chinese punk used to light firecracker-. Often the powder i- moist- 

 ened and molded roughly into small cone-, and after drying it 

 burns readily and perhaps with less waste than doe- the dry powder. 

 Of late years in mosquito-infested countries a number uito 



pastilles have been -old, and many of these are molded from pow 

 that contain more or less Pyrethrum. The efficacy oi the burning 

 pyrethrum in a close room is almost perfect. It will not actually 

 kill all the mosquitoes, but will stupefy them and cause them to tall 

 to the floor where they may be swept tip and burned. With the 

 windows open, however, and the constant currents oi fresh air blow- 

 ing through the room, this fumigation i< not especially effective, 

 ami it is necessary for protection to sit in the cloud of smoke. 



a Bui. 12, old series, Div. Em., \ pt Agr., pp. 7-10, 18* 



