Cyanuret of Potassium. 
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produces carbonates of potash and ammonia, formiate of 
potash, a small quantity of hydrocyanate of ammonia &c, 
products which have no relation as to properties, with the 
cyanuret. 
Moreover, the same cyanuret in a solid state, kept in a 
badly closed bottle, or one which is often opened, is trans- 
formed into hydrocyanic acid, which is disengaged, and into 
carbonate of potash, which is formed at the expense of the 
carbonic acid of the air. This transformation takes place 
very rapidly, when the salt is moist. 
This being admitted, when we refer to the usual method 
of preparing the cyanuret of potassium used in medicine, 
which consists of dissolving and evaporating to dryness the 
product of a calcination of the yellow cyanuret of potassium 
and iron, it must be evident, that during this operation, a cer- 
tain proportion of the cyanuret will be completely decom- 
posed, and that this proportion will vary with the rapidity of 
the evaporation, the temperature employed, the quantity ope- 
rated upon, in short, that a pure product can never be ob- 
tained, nor one which is identical w 7 ith the results of other 
operations. Hence, in making use of a cyanuret thus pre- 
pared, a physician is always exposed to unpleasant conse- 
quences. 
Suppose for instance, a physician after having prescribed 
a grain of the cyanuret of potassium, without obtaining the 
desired result, gradually increases the dose to two, three, or 
even four grains ; if the cyanuret be moist, and has under- 
gone a change, these four grains may be only equivalent to 
two grains of the pure cyanuret, and may produce a benefi- 
cial effect ; but if, after having thus made use of the prepa- 
ration in this state, the same patient should employ the 
same dose of a pure and dry cyanuret, this change doubles 
the strength of the remedy, and may cause the most fatal 
results. 
There exists, however, a mode of avoiding this danger, 
which is by never employing for medicinal purposes, any 
other than the fused cyanuret 
When the retort is broken, in which the cyanuret of potas* 
