THE ASH OF PLANTS. Ill 



acids. In the pure state it is a colorless, oily liquid, having the odoi 

 of tobacco iu an extreme degree. It is inflammable and volatile, and so 

 deadly that a single drop will kill a large dog. French tobacco contains 

 7 or 8 p. c.; Virginia, 6 or 7 p. c.; and Maryland and Havauna, about 2 p. 

 c. of nicotin. Nicotin contains 17.3 p. c. of nitrogen, but no oxygen. 



4/aiIoiu, C 8 H 10 N 4 O 2 , exists in coffee and tea combined with tannic 

 \ acid. In the pure state it forms white, silky, fibrous crystals, and has a 

 \bitter taste. In coffee it is found to the extent of one-half per cent ; in 

 (tea it occurs in much larger quantity, sometimes as high as 6 per cent. 



r riieol&amp;gt;romiii, C 7 H 8 N 4 2 , resembles caffeiu in its characters, 

 and is closely related to it in chemical composition. It is found in the 

 cacao-bean, from which chocolate is manufactured. 



Thft_ajkj.loiti^^ire^miu-kai)lp, from containing nitrogen, and from hav 

 ing strongly basic characters. They derive their designation, alkaloids, 

 &amp;lt; MF likeness to the alkalies. 





CHAPTER II 

 THE ASH OF PLANTS. 



1- 



THE INGREDIENTS DF THE ASH. 



As has been stated, the volatile or destructible part of 

 plants, i. e. the part which is converted into gases or vapors 

 under the ordinary conditions of burning, consists chiefly 

 of Carbon, Hydrogen, Oxygen, and Nitrogen, together 

 with minute quantities of Sulphur and Phosphorus. 

 These elements, and such of their compounds as are of 

 general occurrence in agricultural plants, viz., the Organic 

 Br,pximate Principles, have been already described in detail. 

 / The non-volatile part or ash of plants also contains, or 

 may contain, Carbon, Oxygen, Sulphur, and Phosphorus. 

 It is, however, m general, chiefly made up of eight other 

 elements, whose common compounds are fixed at the or4i- 

 nary heat of burning. 



