THE CULTURE OF TOhACUO. 131 



eleiueats have, however, been obtained, and until these are under- 

 Mtiicid l)y the tobacco planter, he will not be aljle to exercise his 

 best judgment in the matter of the fertilization of the soil. The 

 organic compounds seem to bear the closest relation to the aroma 

 of the tobacco, while on the inorganic salts depends largely its 



combustibility. It has been determined liy experiments in Europe, 

 America, and Japan — 



1. That chlorine is injurious to the burning nualities of the 

 leaf, and that the excess of sulphuric acid is also injurious in the 

 same way. 



2. That the presence of a large amount of pota,sh in the tobacco 

 greatly improves the buin, but that the comljustiljility i.s not pro- 

 portional to the percentage of potash present, but is depjendent 

 tra the amount of potash in excess of the amount required to 

 combine with the mineral acids such as chloric and sulphuric acids, 

 and that the potash, when in the form of a carbonate, gives the best 

 results. 



3. That the alkalinity of the a.sh has a marked effect for gond 

 on the combu.stibility. 



4. That a certain amount of lime, where jjotash is deficient, 

 may comVjine with the free acids, and improve coniljustibility, but 

 that an excess of lime may be harmful. 



5. That the small percentage of iron and aluminium oxides that 

 may lie pi-esent in the leaf have no apparent effect on the com- 

 bustibility. 



Tobacco plants require certain quantities of several different 

 elements, as lime, potash, sodium, ii'on, sulphur, phosphorus, chlorine, 

 nitroo'en, &c., to complete their development, but it will be seen 

 that the presence of an excess of some of the elements, as sulphuric 

 and chloric acids, is harmful to the commercial product, and that 

 the presence of other elements, as potash, in excess of the real 

 needs of the plant is benefieial to the cured article. Therefore, the 



