Virulence of Desiccated Tubercular Sputum. 495 



* c Virulence of Desiccated Tubercular Sputum." By Harold 

 Swithinbank. Communicated by Sir James Crichton 

 Browne, F.K.S. Beceivecl May 31 — Eead June 20, 1901. 



In the spring of 1900 two plots of a superficial area of 44 sq. feet 

 each were carefully partitioned off in the experiment house with close 

 mesh-wire netting, and laid down with closely cropped lawn turf, 

 which quickly grew into an even sward. 



On the 16th day of May following, the grass of these two plots 

 having been cut as short as possible (not exceeding a length from the 

 ground surface of one-quarter to one-half of an inch), the two plots 

 were watered evenly with 4 gallons of water, in which had been incor- 

 porated 3 pints of disintegrated tubercular sputum from the Brompton 

 Consumption Hospital, 2 gallons being distributed over the grass of 

 each plot by means of an ordinary watering can with a rose spout. 



The plots were then left for fourteen days under the following con- 

 ditions, being designated respectively as Plot "T A" and Plot "TB," 

 that is to say : — - 



Plot " T A " was exposed during the whole of the fourteen days to 

 all climatic influences, including the direct rays of the sun between the 

 liours of 10 a.m. and 6 p.m. The weather was exceptionally dry and 

 fine. 



Plot " T B" was for the same period exposed to the same conditions 

 as the above, with the exception of the sun's rays, from which it was 

 carefully shielded. 



On the 30th May the following animals were turned down to feed 

 upon the two plots : — 



Plot "A." Plof'B." 



Two rabbits. Three rabbits. 



Three guinea-pigs. Three guinea-pigs. 



These animals were marked as follows : — 



Eabbit T 2. 

 Habbit T 3. 

 Guinea-pig T 6. 

 Guinea-pig T 7. 

 Guinea-pig T 8. 



Both fore-paws red. 

 Left fore-paw red. 

 Right hind-paw red. 

 Right hind-paw blue, 

 Left hind-paw blue. 



Rabbit T 1. 

 Rabbit T 4. 

 Rabbit T 5. 

 Guinea-pig T 9. 

 Guinea-pig T 10. 

 Guinea-pig T 11. 



Right fore-paw red. 



Red nose. 



Blue nose. 



Right fore -paw red. 



Both fore-paws red. 



Right fore-paw blue, 



The short grass on the plots was quickly eaten down, when the 

 ground became completely bare and, owing to drought and the 

 scratching of the rabbits, covered with a layer of fine dust. The 

 animals were then fed upon moistened bran, contained in dishes, and 

 greenstuff thrown upon the ground. 



The two tables marked "A" and "B" respectively, and attached 



VOL. LXVIII. 2 N 



