146 NEW YORK STATE MUSEUM 



been the experience of several Albanians in the past summer, 

 and the most practical way of ridding the house of these vermin 

 is by thorough fumigation with hydrocyanic acid gas, using 1 

 fluid ounce of sulfuric acid diluted with 2 fluid ounces of water 

 and 1 ounce of high grade (98;?^) cyanid of potassium for every 

 100 cubic feet of space. A preliminary fumigation using half the 

 above amounts and continuing the treatment two hours killed 

 practically all the Psocids in the house and many fleas, while 

 the usual amounts with a six hour fumigation destroyed all the 

 fleas. The acid and cyanid are among our most deadly and 

 virulent poisons and the same is true of the generated gas. Be- 

 fore floating, the house should be first carefully examined and 

 every orifice or crack which would allow the egress of air should 

 be carefully stopped. All fluids and liquid foods should be re- 

 moved from the house and arrangements made so that the build- 

 ing can be opened from the outside after fumigation. The gas 

 is generated by dropping the cyanid in large earthenware vessels 

 containing the proper amount of diluted acid. It will be found 

 advisable to have one or two of these jars in each room or hall- 

 way, and so arrange matters that the cyanid while still in the bag, 

 can be dropped into one vessel after the other very rapidly, or 

 else with a series of strings, dropped into all of the vessels 

 at once. After the charge is set off the house should be care- 

 fully guarded so that no person can enter, and if it be in contact 

 with others in a row, those in adjacent dwellings should also 

 be warned so that the rooms next the treated building may be 

 well aired during the fumigation, which should last from one to 

 several hours. The building should then be thoroughly aired by 

 opening doors and windows from the outside, and utmost pains 

 taken to free the house of gas before any one be allowed to enter. 

 The airing should last at least 30 minutes, and it will be prefer- 

 able to extend this time to one, two or even three hours, depend- 

 ent somewhat on the size of the building and the facilities for 

 ventilation. One treatment should be sufficient but in the case 

 of poorly constructed houses a second fumigation may be neces- 

 sary a week or 10 days later. This dangerous operation should 



