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SELECTED ARTICLES. 
therefore, be necessary, as sometimes happens in surgical 
cases, to use the probe, even although it should touch the 
quick. 
Dr. Thomson, in his evidence, states that sulphate of ba- 
ryta is a common adulteration of calomel, but we lately dis- 
covered a deterioration of a much more serious nature in that 
important remedy. A quantity of that drug, got from a 
wholesale London house, indicated very distinctly the pre- 
sence of corrosive sublimate; we therefore washed it com- 
pletely, and on drying it carefully we found that the six 
ounces of perfectly dry calomel which we used, had lost 
exactly one drachm; the solution answered to all the tests for 
the bichloride; we then revived the mercury, with a solution 
of the protochloride of tin, but from an accident that unfortu- 
nately occurred to the vessel in which the process was conducted 
before we could get the mercury weighed, we could notascertain 
the exact quantity. Now, allowing that there was a drachm, 
and there could not be much less, from the quantity of metal- 
lic mercury recovered, we would have one grain of corrosive 
sublimate in every forty-eight of the impure calomel ; a 
quantity, we should conceive, very likely to produce serious 
consequences in certain cases, when large or frequently re- 
peated doses are given; or, at all events, very much to obscure 
the results of treatment. Although this deterioration cannot 
have been designed, the result is equally serious, and must have 
arisen either from the grossest ignorance, or the most culpable 
carelessness, and shows the necessity of allowing no one to 
enter into any department of the drug trade without the most 
searching examination of his knowledge of pharmacy, both 
practical and theoretical. 
The evidence of Dr. Thomson regarding the inferiority of 
the extracts supplied to the profession is fully confirmed by 
the facts that have come to our knowledge. Is it not amazing, 
that notwithstanding the admitted superiority of the extracts 
prepared according to Barry's method, and which has now 
been so long known to the profession, it has hitherto been 
almost impossible to procure them, but that the ordinary 
