OF THE NITROGEN OF PLANTS. 79 



to experiment were taken from a wood several miles 

 distant from any house, and yet the clarified juice, 

 evaporated with lime, emitted a strong odour of 

 ammonia. 



In the manufactories of beet-root sugar, many 

 thousand cubic feet of juice are daily purified with 

 lime, in order to free it from vegetable albumen and 

 gluten, and it is afterwards evaporated for crystal- 

 lization. Every person, who has entered such a 

 manufactory, must have been astonished at the 

 great quantity of ammonia which is volatilised along 

 with the steam. This ammonia must be contained in 

 the form of an ammoniacal salt, because the neutral 

 juice possesses the same characters as the solution 

 of such a salt in water ; it acquires, namely, an acid 

 reaction during evaporation, in consequence of the 

 neutral salt being converted by loss of ammonia 

 into an acid salt. The free acid which is thus 

 formed is a source of loss to the manufacturers of 

 sugar from beet-root, by changing a part of the 

 sugar into uncrystallisable grape sugar and syrup. 



The products of the distillation of flowers, herbs, 

 and roots, with water, and all extracts of plants 

 made for medicinal purposes, contain ammonia. The 

 unripe, transparent and gelatinous pulp of the 

 almond and peach emit much ammonia when treated 

 with alkalies. (RoUquet.) The juice of the fresh 

 tobacco leaf contains ammoniacal salts. The water, 

 which exudes from a cut vine, when evaporated with 

 a few drops of muriatic acid, also yields a gummy 



