40 FIRESIDE SCIENCE. 



than a single ton of tobacco. The activity of chem- 

 ical forces, therefore, necessary in the growth of the 

 plant, must be exceedingly great ; and the curious 

 and complex character of the vitalized structure 

 stamps it as among the most extraordinary pertain- 

 ing to the vegetable kingdom. Aside from the ash 

 constituents, the chemistry of a cigar, in respect to 

 agents directly influencing the animal economy, is 

 the same as the chemistry of tobacco in any form. 

 The chemical agents contained in tobacco are 

 brought in contact with the same tissues and mu- 

 cous surfaces, whether the form be that of smoke, 

 as in smoking, or aqueous extract, as in chewing, 

 or of substance finely divided, as in snuff-taking. 

 Tobacco and tobacco smoke contain three impor- 

 tant and distinguishing chemical agents, which con- 

 fer upon them peculiar properties. If we take a 

 common glass retort and affix to it a condenser, 

 and place in the retort a pound of fresh tobacco 

 leaves with a pint of water, upon applying heat and 

 distilling, a minute quantity of volatile oil comes 

 over and floats on the water in the receiver. This 

 has a pungent odor, and appears to be the aroma, 

 or condensed essence of the plant. When held to 

 the nose, it causes violent sneezing ; and, if placed 

 on the tongue, the whole of the mouth and throat 

 seems to be instantly pervaded -with the strong taste 

 of tobacco. To the smoker, this principle is most 



