NOTES ON RECENT RESEARCH, 



255 



In short all the pros and cons should be carefully weighed before treat- 

 ment is determined upon. 



Preparations for Treatment. — The building should be made as tight 

 as possible. If glass is out it should be reset, doors and windows should 

 be made to fit snugly, and a special examination should be made for 

 cracks and leaks around the floors and lower walls. The place should be 

 thoroughly swept and cleaned, and a coat of whitewash may sometimes 

 be desirable. The material infested may be exposed, and, if movable, 

 placed on the floors. 



Shallow tin pans or plates make good evaporating dishes. The larger 

 the evaporating area the better. There should be about one square foot 

 of evaporating surface to every 25 square feet of floor area, and each 

 square foot of evaporating surface should receive from \ to 1 lb. of liquid. 

 These figures are, of course, only suggested and approximate. Pans 

 should be placed as high in the room as possible, since the vapour is so 

 heavy that it settles most heavily to the lower parts. Care should 

 be taken, when placing the pans, to see that they are nearly level, though 

 ordinarily no particular harm will be done if some of it is spilled. It 

 should not be found necessary to lose time in adjusting such things after 

 the application is begun. If there are special places — difficult of access 

 for treatment with the pans — cotton waste, bundles of rags, or the like 

 may be saturated and thrown into these places. Everything should be 

 done to avoid unnecessary delays and to facilitate the rapid exposure of 

 the liquid. If the liquid is bought in large quantities, small receptacles 

 may have to be provided for transferring it to the pans. 



The Exposure of the Liquid. 



As many men may assist in the exposure as can work to advantage. 

 Before the cans or drums are opened the men should be cautioned as to 

 the nature of the liquid, the danger from fire, and the necessity for rapid 

 work. If more than one floor is to be treated, begin at the bottom and 

 work upwards. Carefully close and fasten all windows and outer doors, 

 except one through which exit is to be made when the operation is com- 

 pleted. Pour out the liquid as rapidly as may be done, giving each pan about 

 its predetermined amount, and then get out quickly. Close the door and 

 keep it locked for twenty-four hours at least — longer if possible. The best 

 plan usually is to apply the liquid after work-hours but before dark 

 Saturday evening, and leave the building closed till the following Monday 

 morning. 



Ventilation. — Doors and windows are then opened wide at least one 

 or two hours before it is time to resume work. The vapours disappear 

 rapidly in the open air, and after an hour there will ordinarily be no 

 danger in entering and but little trace of the disagreeable odour. Slight 

 traces of the odour will probably linger in the corners and places where 

 tne air does not move freely, but these gradually disappear. 



Precautions. — Attention has been called to the dangers from fire in 

 the presence of carbon bisulphide vapour in the air, but special reference 

 should be made to it in connection with the treatment of buildings. It 

 is customary to mention the danger of bringing a lighted cigar or any 

 such thing into the presence of the fumes. The application should always 



