June, 1907.] Ablt. — AV 



L'MJN OE NAPHl 



'HALUJNE OX J 



^LAJSTS. 





Weight 



Weight 





Naphthalene. 



of 



of . 



Total. 





straw. 



grains. 







g- 



g- 



g- 



" 1 



12.5 

 10.0 



7.0 

 9.0 



138.5 



0.5 | 



5.8 

 6.5 



2.0 

 2.0 



jl6.3 



Check pots. < 



13.5 

 12.5 



9.0 



8.5 



i43.5 



113 



The observations show therefore : 



1. Naphthalene can prevent the development of various 

 soil bacteria, although it does not kill them. 



2. Naphthalene, in the proportion of 0.005-0.01% added 

 to soil, can cause in some cases a moderate stimulation of 

 growth with phaenogams, as with barley, buckwheat and 

 millet, but not with pea and rice. An increase to 0.05% injured 

 the growth in every case. The injurious action must be ascribed 

 to the vapors of naphthalene spreading through the pores of 

 the soil. 



3. Since naphthalene injures the plants it cannot be recom- 

 mended as a remedy against nematodes, at least not in doses 

 of more than 0.05% of the soil. 



