424 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 15 



Sea Sand 

 Dolomite 



Sea Sand is a poorer absorbent than dolomite and releases more 

 nicotine with an approximately dry air stream than dolomite. The 

 wetting of the sand causes a film of moisture to cling to the particles and 

 a part of the moisture ,'is easily evaporated by the air, while some of the 

 liquid may be absorbed or has greater adhesion in the case of dolomite. 



Sand is too heavy to be used for practical purposes for a considerable 

 force is necessary to blow it for sufficient distribution. For dusting 

 ground crops Magnesium limestone seems a good carrier, is cheap and 

 convenient, does not bum the plants and has a good adhering quality; 

 it can be used to advantage with nicotine sulfate and "free" nicotine. 

 For orchard dusting a light fluffy carrier is needed. In the case of 

 "free" nicotine liquid ordinary hydrated lime can be used and with 

 nicotine sulfate hydrate of lime with 10 per cent dolomite which gives 

 about as good nicotine delivery as dolomite alone. 



Conclusions 



I. Nicotine derived from nicotine sulfate: 



1. Is evolved less rapidly from a colloidal than from a crystalloidal 

 carrier. 



2. Is evolved most readily when a large percentage of carbonates 

 (Ca and Mg) is present. 



3. Is evolved more readily under influence of high temperature and 

 high atmospheric moisture conditions. 



II. Nicotine derived from high strength (95%) "free" nicotine solution: 



1 . Is evolved more readily from a crystalloidal than from a colloidal 

 carrier. 



2. Is evolved from dolomite, hydrated lime, etc. at approximately 

 the same rate. 



3. Is evolved more rapidly under high temperature and low atmos- 

 pheric conditions. 



4. Is evolved much more rapidly under high temperature and low 

 atmospheric conditions than from nicotine in the sulfate form. 



