258 TOBACCO. 



of the leaf; their presence, however, considerably affects 

 the quality of the tobacco. 



The amount of ash constituents in the tobacco is con- 

 siderable, varying between 16 and 28 per cent. There 

 cannot be said to exist a definite relation between the 

 total amount of ash in the tobacco and its quality, as 

 tobaccos yielding much ash are sometimes of good, and 

 at other times of bad, quality ; a good tobacco may yield 

 much or little ash. The relative proportion in which 

 the ash constituents exist is, however, of the greatest 

 importance. It has been ascertained that the presence 

 of some special mineral elements modify to a great 

 extent the quality of the tobacco. Of all ash consti- 

 tuents, potash (KgO), more correctly speaking potassium 

 carbonate (KgCOg), affects the quality of tobacco in the 

 highest degree. Schlosing has pointed out that the good 

 burning qualities of a tobacco depend on the presence in 

 it of potash in combination with a vegetable acid ; that 

 a soil deficient in potash is unfit to produce tobacco of 

 good quality. Numerous analyses have tended not only 

 to corroborate the assertion made by Schlosing, but to 

 demonstrate also, that it is not the total amount of 

 potash, but the potash found as a carbonate, which 

 existed in the plant in combination with a vegetable 

 acid, that is the constituent chiefly affecting the com- 

 bustibility of a tobacco. The complete analyses of 

 Nessler have shown that, although a tobacco may contain 

 a great amount of potash, it does not necessarily follow 

 that the tobacco burns well. He found that some German 

 tobaccos contained more potash than Havana, although 

 the latter burned much better than the former : and that 



