304 



BULLETIN No. 161 

 TABLE 6 Continued 



[November, 



Author 



Date 



Conditions 



Not killed 



Killed 



Kuss' 



1908 



Tuberculous sputum dried in thin 

 layers in the dark, free to the air: 



Virulence wholly preserved 



Virulence diminished 



Virulence much decreased, yet a 

 large dose produced a tuberculous 

 guinea pig 



Virulence entirely lost 



Tuberculous sputum, dried in thin 

 layer, in diffuse light of a room 

 rapidly decreased in virulence: 



Noticeable decrease 



Marked decrease 



Very noticeable decrease 



Not entirely lost 



Entirely lost 



Two guinea pigs were expos'ed to the 

 dust made by shaking of hand- 

 kerchiefs on which tuberculous 

 sputum had been dried for 25 days. 



Neither became tuberculous 



Six guinea pigs were exposed to the 

 dust from a plank containing 

 sputum that had been drying for 



17 days. Remained healthy 



Experiments in a box of 125-liter con- 

 tent: 



Tuberculous sputum dried for 6 days 

 in the dark was powdered and 1 

 to 2 grams suspended in the air of 

 this box. Guinea pigs with their 

 heads projecting into this box 

 were made to breathe this dust 

 from 30 to 60 minutes. In all cases 

 the guinea pigs became tubercu- 

 lous 



Experiments in a room of 30 cubic 

 meters: 



Series i 125 cc. of tuberculous 

 sputum were dried on a carpet 

 from 11 to 13 days. Nine guinea 

 pigs were swung 60 to 90 inches 

 above this carpet. Then the car- 

 pet was beaten and swept for 20 

 minutes. Four of the 9 guinea 

 pigs became tuberculous. Also 

 the dust obtained by the aspira- 

 tion of 60 liters of air, at a point 

 60 inches above this carpet, was 

 inoculated into a guinea pig, 

 which became severely tubercu- 

 lous 



Series 2. 20 cc. of tuberculous spu- 

 tum were dried on another carpet 

 for 6 days. Six guinea pigs were 

 suspended above this carpet, 

 which was beaten and swept for 

 12 minutes. Two of the 6 guinea 

 pigs became tuberculous. Also 



12 to 14 days 

 18 days 



20 to 30 days 



3 days 



7 days, 



10 days 



15 days 



40 to 50 days 



20 days 



25 days 

 15 days 



6 days 



11 to 13 

 days 



