18 M. Berzelius’s Analysis of the SidpMirous 
M. Berzelius compares the idea of making it a particular 
acid to that of considering cream of tartar as an acid of sel 
seignette or of tartar emetic. 
Most of the ferruginated prussiates are capable of being dis- 
solved in concentrated sulphuric acid, without experiencing; any 
decomposition. In allowing the acid to attract the humidity of 
the air, the new combination deposits itself often in the form of 
crystals. The combinations are acid salts, with two bases and with 
two acids. They are not formed of cyanurets and sulphuric 
acid, because the prussiate of iron, with excess of acid, (Ferru- 
retted Chyazic Acid), combines also without alteration with con- 
centrated sulphuric acid. 
M. Berzelius tried in vain to produce the new gas which Dr 
Thomson pretends to have discovered, in treating the ferrugi- 
nated prussiate of potash by concentrated sulphuric acid. 
The double cyanuret of iron and potassium, mixed with sul- 
phur, and heated, combines with the last at a temperature which 
exceeds a little that of melted sulphur. Hence, there results a 
new combination, which M. Berzelius calls a Sulpho-cyanuret 
(f Potassium^, mixed with a Sulpho-cyanuret f Iron, The 
latter decomposes itself in part, in proportion as the temperature 
rises, and gives birth to sulphuret of iron, which remains near 
the sulpho-cyanuret of potassium, and to sulphuret of carbon, 
an azotic gas, which escape together. 
The sulpho-cyanuret of potassium is soluble in water and in 
alcohol, from which it is obtained by crystallization : the crys- 
tals contain no water, that is to say, they are not converted into 
sulphuretted hydro-cyanite of potash. Each atom of cyanuret 
of potossium combines with 4 atoms of sulphur, from which it 
follows, that the composition of the sulpho-cyanuret may be ex- 
pressed after the method of M. Berzelius, by K -f SNC^S^. 
That is to say, that in the case where the elements are oxidated, 
there would result either neutral nitrate of potash, or bicarbo- 
nate, or bisulphate of potash. 
M. Berzelius considers the sulpho-cyanurets as containing a 
compound electro-negative particular body, which he calls Sul- 
phuret of Cyanogen, and which is composed of equal volumes 
(or atoms) of azote, carbon, and sulphur. The sulphuretted 
hydro-cyanic acid which results from the combination of sul- 
