OF THE NITROGEN OF PLANTS. 77 



Greifswalde, Wick, Eldena, and Kostenhagen, con- 

 tain carbonate and nitrate of ammonia. Ammo- 

 niacal salts have been discovered in many mineral 

 springs in Kissingen and other places. The am- 

 monia of these salts can only arise from the atmo- 

 sphere. 



Any one may satisfy himself of the presence of 

 ammonia in rain, by simply adding a little sulphuric 

 or muriatic acid to a quantity of rain-water, and 

 evaporating this nearly to dryness in a clean porce- 

 lain basin. The ammonia remains in the residue, 

 in combination with the acid employed ; and may 

 be detected either by the addition of a little chloride 

 of platinum, or more simply by a little powdered 

 lime, which separates the ammonia, and thus 

 renders its peculiar pungent smell sensible. The 

 sensation which is perceived upon moistening 

 the hand with rain-water, so different from that 

 produced by pure distilled water, and to which the 

 term softness is vulgarly applied, is also due to the 

 carbonate of ammonia contained in the former. 



The ammonia, which is removed from the atmo- 

 sphere by rain and other causes, is as constantly 

 replaced by the putrefaction of animal and vegeta- 

 ble matters. A certain portion of that which falls 

 with the rain, evaporates again with the water, but 

 another portion is,we suppose, taken up by the roots 

 of plants, and entering into new combinations in 

 the different organs of assimilation, produces albu- 

 men, gluten, quinine, morphia, cyanogen, and a 



