THE TOBACCO PLANT. 29 



The commercial value of tobacco leaves is in an inverse 

 ratio to the amount of albumen which they contain, that 

 sort of tobacco being most highly esteemed by smokers 

 Avhich contains the least albumen ; for the latter ingredient, 

 in the burning of the dry leaves, emits on carbonisation a 

 most disagreeable smell of biu-nt horn shavings. The 

 leaves rich in albumen contain, as a rule, more nicotine 

 than those which are poor in albumen ; they give the 

 strongest kinds of tobacco, man^^ of which cannot be 

 smoked unmixed. 



The tobacco leaves cultivated in France and Germany 

 are manufactured either into smoking tobacco, or into 

 snuff. For the fabrication of snuff, leaves which are rich 

 in albumen and nicotine are preferred to those containing 

 a smaller amount of those ingredients. The leaves in- 

 tended for snuff are, either when still entire or after being 

 ground to powder, subjected to a kind of fermentation, 

 wdiicli takes place pretty speedily, with evolution of heat, 

 if they are kept moistened with water. From the putre- 

 faction of the albumen there arises a considerable quantity 

 of ammonia, wdiich is a principal ingredient of German 

 snuff, and is also occasionally increased by the manufac- 

 turers, by moistening with carbonate of ammonia or caustic 

 ammonia, to suit the taste of consumers. 



The leaves intended for smoking are also improved in 

 quality by a slight process of fermentation, which serves 

 to diminish the quantity of albumen in them. 



These preliminary remarks will help to explam the 

 different methods of cultivating tobacco. 



The size of the leaf in length and breadth, its light or 

 dark colour, the height of the stem, the amount of pro- 

 duce, and tlie greater or less proportion of albumen and 

 nicothie, all depend very essentially upon the manuring of 

 the plant. 



