COMrOSlTlON OF PLANTS. 231 



ous ingredients of the plants, as is shewn by the hurtful pro- 

 perties of the honey produced by bees from the Azalea j)oiu 

 Oca and Kalmia latifolia. 



353. 



Azote being thus a constituent part of mucilage, it is 

 also, in an especial manner, evolved in albumen and ghi- 

 tcn, so that these are considered as properly the ingredients 

 of animal matter. In the leguminous fruits, tliese are the in- 

 gredients which render the plants so peculiarly nutritious. 

 In the juice of the Agave Americana^ which is the favourite 

 drink in Mexico, there is so much of these animal matters, 

 that tJiis liquor smells strongly of putrid flesh. Albumen, in 

 moderate warmth, passes into a putrid decomposition, during 

 which sulphurated hydrogen gas and azotic gas are disen- 

 gaged, and sulphur and phosphorus are generated. With 

 weak nitric acid, it disengages azotic gas, and in a stronger 

 heat it gives out cyanogen : by distillation we obtain carbo- 

 nated hydrogen, ammonia, and empyreumatic oil. It con- 

 sists, according to the French analysis, of 52 parts of carbon, 

 23 of oxygen, 15 of azote and of hydrogen. 



Gluten is only distinguished from albumen by its greater 

 consistence, and by this further circumstance, that it is inso- 

 luble in water, but moderately so in spirit of wine. 



354. 



We further find extractive matter, tannin, and colouring 

 matter, all existing as ingredients of plants. The extractive 

 matters are indeed very various, but they seem to be formed 

 from mucilage by a difference in the pro}X)rtion of their 

 oxydation, and by a mixture of the peculiar matter of plants. 

 Extractive matters are insoluble in water, and they also so 

 far partake of the nature of mucilage, that they enable oil to 

 mix with water, and to be used as soap. They contain also so 

 much oxygen, that they redden the blue juices of vegetables, 

 and the bitter taste of most of these substances proceeds from 

 carbon oxy dated to a certain pitch, and whicli has been dc- 



