456 HOUSEHOLD INSECTS 



mosquitoes. The gas is produced by burning flowers of 

 sulfur or lump sulfur. 



There are certain objections to the use of sulfur as a 

 fumigant in the household. The gas is liable to bleach 

 wall papers and fabrics and to tarnish metals, like brass, 

 copper, silver, and gilt. The bleaching effect will depend 

 upon the amount of moisture present in the rooms. It is 

 desirable, when fumigating with sulfur, to have the build- 

 ings and contents as dry as possible in order to avoid the 

 formation of sulfuric acid which causes the bleaching. 

 Again, it has been shown that the gas affects the baking 

 qualities of wheat flour at least. It is presumable that the 

 fumes would also affect other ground cereals used for 

 baking, as graham flour and meal. Harcourt has shown 

 that wheat flour fumigated with sulfur dioxide makes 

 very sticky, fluid-like dough that is not at all satisfactory. 

 He has also shown that the loaves baked from this flour 

 did not rise well and were smaller in volume than those 

 from the untreated flour. Moreover, sulfur fumes, 

 when used strong enough to kill insects in grain, destroy 

 the germinating power of the seeds. The grain is not 

 injured for purposes of food, but its usefulness for planting 

 is destroyed. This fact should be borne in mind when 

 using sulfur as a fumigant in the household. Corn, wheat, 

 or other grains stored for seed planting purposes should 

 be removed and not subjected to the action of the fumes. 



Notwithstanding these objections, sulfur dioxide is now 

 considered the most reliable of all fumigants in epidemics 

 of yellow fever and in all cases where mosquitoes are 

 concerned. 



Howard says that Rosenau of the U. S. Public Health 

 and Marine-Hospital Service has made a rigid series of 



