ON CYANIDE OF POTASSIUM. 
135 
total decomposition on entering the stomach — an effect 
which unfortunately cannot be controlled by the physician, 
as the weakest acid will decompose it in preference to 
uniting with carbonate of soda, magnesia, or any other com- 
pound with which it is usually administered. Should it 
meet with free carbonic acid in the stomach, prussic acid 
would gradually be eliminated, producing the pleasant 
effects which often result from its exhibition ; but when it 
meets with a stronger acid in sufficient quantity, 10 minims 
or Bi of prussic acid are at once liberated, causing vertigo, 
peach kernel eructations, and other distressing conse- 
quences.* 
In an article published in this Journal, Vol. 1, No. 1, 
p. 264, I endeavored to show, from the authority of some 
of the first chemists in Europe, that it was very liable to 
vary in strength during the most careful preparation, and 
that it is extremely apt to suffer decomposition from va- 
rious causes, after it has been prepared in the most judi- 
cious manner. Its subsequent introduction into the new 
Pharmacopoeia, and its popularity among the physicians of 
our city, have led me to test the veracity of the eminent 
chemistst referred to, as to its variable quality. I procured 
six samples from six of the best retail stores of Baltimore, 
where the great proportion of prescriptions are compounded. 
Each was carefully weighed with the same weight, and im- 
mediately transferred into a solution of nitrate of silver in 
dilute nitric acid, using the same proportion of nitrate in 
each case. The result was an insoluble precipitate of cya- 
nide of silver, corresponding with the proportion of cyano- 
gen existing in the cyanide of potassium. 
* These results have followed its exhibition in medium dose on se- 
veral occasions in our city, in the hands of some of the most eminent 
physicians, and those who have used it most frequently. 
j Dr. Trouve, MM. Pelouse and Gieger, and M. Boidet. 
