610 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



Interstate samples collected. 



Number of 

 Class of samples. samples. 



Arsi'iiate o{ ciilciuui 102 



Arsfiiatt' ol' li'iul r,i 



Hdidcaiix mixture jiiid combinations of Bordeaux mixture with insecticides.I 79 



Ciiliiriiialed lime q 



Dips lor animals 20 



Disinfectants, ;rerniicides, bactericides 83 



Fly preparations lor animals 33 



Fisli-oi! and wiiale-oil i)rt'i>arations 9 



Formal del lyde jtrepa rations 8 



Insect j)reparations, liousehold use 52 



Insecticide and funf:;icide preparations, agricultural use 92 



Kerosene enuilsions 5 



Lice and mite Ivillers 32 



Lime-snlplmr solution and sulphur preparations 32 



Nicotine preparations 6 



Taris j^reen 24 



Pyretiiruni and hellebore powders 43 



Miscellaneous 40 



IMPORT SAMPLES. 



During the year 170 official and unofficial import samples of in- 

 secticides and fungicides were collected by the various port labora- 

 tories of the Bureau of Chemistry for examination and test by the 

 board. Disposition was made of 174 samples; 4 official samples were 

 found adulterated and misbj'anded, and it Avas recommended that 

 the consignments be refused entry until correctly labeled. The re- 

 mainino; samples were unofficial, 49 of them being found to be 

 adulterated or misbranded, or both, and in these cases it was recom- 

 mended that future shipments be detained, while 121 were neither 

 adulterated nor misbranded. 



SPECIAL INVESTIGATIONS. 



The investigation begun several years ago to discover a method of 

 determining stems in insect powder, determine reasonable standards 

 for insect powder, and study the composition of the raw materials 

 and of the finished product, as well as the process of manufacture, 

 has been completed and published as Bulletin 824, United States De- 

 partment of Agriculture, under the title " Insect Powder." In this 

 bulletin a very complete history is given of the early uses of various 

 species of pyrethrum, of the cultivation and harvesting of insect 

 flowers, of the preparation of insect powder, of the effect of insect 

 powder on insects, of the various adulterants of insect powder that 

 have been used, and of the physiological, microscopic, and chemical 

 methods of detecting adulterants in insect powder. A section on 

 the microscopic examination of insect powder is given, together with 

 a combined chemical and microscopic method for determining the 

 amount of stems in insect powder. Many tables of analyses of authen- 

 tic samples of insect flowers, insect powders, and stems, are given, 

 on the basis of which the permissible amounts of sand and stems 

 in insect powder have been determined. A resume is given of pre- 

 vious investigations of the active principles of insect powder, and 

 certain original work puljlished which indicates that the insecticidal 

 activity of pyrethrum is due to a mixture of acids and esters. 



