THE EFFECT OF SOOT ON VEGETATION. 19 



At end of time all plants were alive. The leaves of 

 the plants treated displayed a tendency to drooping. Many 

 leaves began to die at the tips. Those near the ground 

 were completely dead. Old leaves seemed to suffer most 

 from treatment. The control remained normal. 



EXPERIMENT II. 



During August, 1912, under similar conditions with 

 the same kind of seedling and in the same nursery. The 

 soot applied of sample B. Quantities of soot used as fol- 

 lows : In case No. 1, .219 gm. per square meter. No. 2, 

 .219 gm. per square meter. No. 3, .439 gm. per square 

 meter. No. 4, Control. 



The results were like those in experiment 1. 



EXPERIMENT III. 



During March, 1913. In the College greenhouse. 

 Potted plants of tomato used. Other conditions similar 

 to the above. Soot applied of Sample C. Quantities ap- 

 plied as follows: Case No. 1, 7.2 gm. per square meter. 

 No. 2, 23.04 gm. per square meter. No. 3, 3.6 gm. per 

 square meter. No. 4, Control. 



At the end of the experiment the plants exhibited no 

 differences and all were in good condition. 



EXPERIMENT IV. 



Begun July 21, 1913. Selected Jack Pine seedlings 

 in the nursery as above. Soot applied of sample C. Ap- 

 plied July 21, 22, 23, 24, and experiment continued until 

 August 26, 1913. The following quantities of soot were 

 used : Case No. 1, 23.4 gm. per square meter. No. 2, 11.7 

 gm. per square meter. No. 3, 12.96 gm. per square meter 

 No. 4, Control. 



At the end of the experiment although all plants were 

 alive, nevertheless many of the older leaves were entirely 

 killed and ready to fall off. The younger leaves on the 

 whole endured the treatment better than the older ones. 



