106 
afforded by their incineration, are very various. 
The sulphuric acid combined with potassa, or 
sulphate of potassa, is one of the most usual. Com- 
mon salt is likewise very often found in the ashes 
of plants ; likewise phosphate of lime, which is 
insoluble in water, but soluble in muriatic acid. 
Compounds of the nitric, muriatic, sulphuric, and 
phosphoric acids, with alkalies and earths, exist in 
the sap of many plants, or are afforded by their 
evaporation and incineration. The salts of potassa 
are distinguished from those of soda by their pro- 
ducing a precipitate in solutions of platina : those 
of lime are characterized by the cloudiness they 
occasion in solutions containing oxalic acid ; those 
of magnesia, by being rendered cloudy by solutions 
of ammonia. Sulphuric acid is detected in salts by 
the dense white precipitate it forms in solutions of 
baryta. Muriatic acid by the cloudiness it commu- 
nicates to solution of nitrat of silver ; and when salts 
contain nitric acid, they produce scintillations by 
being thrown upon burning coals. 
As no applications have been made of any of 
the neutral salts, or analogous compounds found 
in plants, in a separate state, it will be useless to 
describe them individually. The following tables 
are given from M. Th. de Saussure’s Researches 
on Vegetation, and contain results obtained by 
that philosopher. They exhibit the quantities of 
soluble salts, metallic oxides, and earths afforded by 
the ashes of different plants. 
