On the Greensand of New Jersey as a source of Potash. 329 
um when the latter is present in greater quantity than the former, 
this observation was considered of little value. — Sr anes 
P A widely different conclusion was arrived at; when chlorid of 
Le calcium was substituted for chlorid of sodium. The’ pulverized 
c and ignited marl was mixed with a sufficient quantity of chlorid 
of calcium to form updén the fusionsof the latter,’ a pasty mass. . 
he decomposition of: the greensand takes place in this case at a 
low temperature, and is so complete that I’ have founded upon 
this circumstance a method of decomposing minerals in the pro- 
cess of analysis, which I have had the honor of presenting to the 
_ Association before. . : a ; Se 
It is evident that the combined water of the greensand must ' 
be expelled by ignition~ previous to fusing it with chlorid of cal- 
ar 
_. ¢ium, otherwise a quahitity of the fused chlorid of calcium will — 
y also be performed in close vessels to avoid the decomposition 
which chlorid of calcium undergoes when fiised in contact with 
th The mass, after fusion, falls to pieces in water, yielding . 
to this solvent, in most cases, all the potash which was contained 
in the greensand employed in the form of chlorid of potassium. 
The separation of this from the excess of chlorid of calcium is an 
easy problem, owing to the difference between their solubilities. 
This application of the chlorid of calcium will open a market 
for the large quantities of this substance which are thrown away 
in some manufactories of soda-ash. 
All attempts to procure sulphate of potash by the fusion of 
_. Various sulphates “with the greensatid were unsuccessful. In 
fact, the greensand ‘itself, at a temperature below the fusing points 
_ of the sulphates of lime and magnesia, fuses to a black glass 
which is no longer decomposable by acids. 
» A great number of other experiments were made upon the 
Tee ut no ‘results were arrived at, which promise to be of 
any practical value except the above. 
A very great number of experiments were also made, having 
for their object to obtain sulphate of potash by fusing together 
chlorid of potassium with alum and with various sulphates, such 
as those of iron, magnesia and-zine, which gave results o | 
practical value, but as these researches had but a fortuitous con- 
nection with those upon the greensand, I shall not introduce an 
account of them here. i 
I will merely remark that if sulphate of potash can be obtained 
by fusing together alum and chlorid of potassium, both of these 
being obtained economically from the greensand by the above 
processes, it is evident that this sulphate of potash may be treated 
Inthe same manner for the production of potash as sulphate of 
_ Soda is in the manufacture of soda-ash, and it seems to me that 
the desideratum of another source of potash is thus supplied. 
Szconp Serres, Vol. X, No. 30.—Nov., 1850. 42 
inevitably be decomposed by the steam evolved. Thé fusion” ye 
