SCIENCE IN ITS APPLICATION. 81 



only about one per cent. There we have different con- 

 ditions of soil in the same climate ; and other instances 

 of a similar character might be cited. 



"As nicotine is the active principle of tobacco, upon 

 which the stimulating effect largely depends, it would 

 naturally appear that its development to a high degree 

 would be desirable, but such is not the case. What are 

 considered the best qualities almost always contain a 

 small percentage, while a large percentage usually indi- 

 cates coarseness. While, as stated, certain conditions 

 are conducive to the development of nicotine, it is un- 

 doubtedly true that the subsequent treatment has some 

 influence on the amount present in the finished product. 

 The different fermentative processes required to develop 

 proper flavor and color necessarily decompose, to a 

 greater or less extent, the different compounds present 

 in the leaf. It may be true, therefore, that in some 

 cases the nicotine content may be appreciably less in the 

 fermented product than was present in the green plant. 

 For this reason, the analyses of the different varieties 

 which have been subjected to different processes of cur- 

 ing and fermenting, cannot safely be relied upon as giv- 

 ing the exact amount developed by certain conditions in 

 the field, but the results, in a general way, confirm what 

 has been previously noted." 



Davidson finds that changes in the amount of nico- 

 tine in leaf at the time of topping, curing, and after 

 being properly cured, are very slight, but in the cured 

 state it seems to be much greater. He questions this 

 latter point. 



Other Substances in Tobacco. Tobacco, like other 

 plants, contains small proportions of starch, sugar and 

 woody fiber, or cellulose, the amount and nature of 

 which governs, to some extent, the burn of tobacco. 

 These elements, together with the fatty and resinous 

 substances present, also have much influence on the 



