COCKROACHES 139 



the gas when confined with a sufficient amount of it in a 

 closed space. It is especially suited for fumigating bath- 

 rooms and pantries and may be used in kitchens if there is 

 no fire in the stove. The gas from carbon bisulfide 

 is inflammable and explosive and great care must be 

 exercised in its use. It should be used at the rate of two 

 pounds to every 1000 cubic feet of space. The best way 

 to apply it is to pour it into shallow vessels, tin pans or 

 basins, close the room tightly, and allow it to remain 

 closed from 36 to 48 hours. Time should be given for all 

 of the liquid to evaporate and for the gas to do its work. 

 After the fumigation is completed the doors and windows 

 should be opened and the room thoroughly aired. While 

 the fumigation is going on no light or fire, in any form, 

 should be brought near the room. 



Buhach. — Another substance used in fumigating for 

 cockroaches is pyrethrum, or buhach. This is a powder 

 obtained by pulverizing the flowers of a plant, pyrethrum, 

 that is now grown in California. Our pyrethrum used to 

 come from Persia and when it arrived here its strength 

 was often greatly weakened, especially after it had stood 

 on the shelves of a store awaiting a purchaser. Now, 

 since it is produced in California, we are much more apt to 

 get it fresh. The American product is sold more commonly 

 under the name buhach. By moistening the powdered 

 buhach it can be molded into cones which, when thoroughly 

 dried in an oven, can be lighted at the tips and will burn 

 slowly and steadily until consumed. The fumes are not 

 poisonous to human beings and they are not explosive, 

 but are often more effective against the cockroach than is 

 the powder applied in the ordinary way. 



Traps. — West wood has described a simple trap for 



