16S 
CHANGE OF CALOMEL. 
of sal ammoniac and of water, calomel is partially changed in- 
to corrosive sublimate. This fact, of which I have ascertained 
the exactness, has always appeared to me very remarka- 
ble, and well worthy of fixing the attention of physicians and 
physiologists. It would not be so, if the assertion of one of 
the most distinguished professors of our school were founded 
in fact. This professor asserts to have proven, by means of 
experiment, that the chemical change of protochloride of mer- 
cury into deutochloride, does not take place under the circum- 
stances stated by the German chemist. I shall not attempt to 
point out whence is the source of the error into which our 
learned colleague has fallen ; I shall at present content my- 
self with publishing the conclusions which result from my ex- 
periments. 
1. The protochloride of mercury, in presence of hydrochlo- 
rate of ammonia, or of the chlorides of sodium or potassium, 
and of pure distilled water, is changed partly into deutochlo- 
ride of mercury, and into metallic mercury. This change 
takes place at the temperature of the human body, and even at 
common temperatures, and demands but few moments of con- 
tact to be effective. It is sufficient, for example, to be con- 
vinced of this fact, to allow calomel to remain a few minutes 
in the mouth ; a mercurial taste, of sufficient intensity, will not 
be slow in exhibiting itself. This taste is the result of the mu- 
tual reaction of the chloride of mercury, and the alkaline chlo- 
rides in the saliva. 
2. It is to the change of calomel into corrosive sublimate, 
and metallic mercury under the influence of sea-salt and the 
salts of ammonia, which we know exist in the liquids of the 
alimentary canal, that we must attribute the pathological phe- 
nomena of mercurial salivation, from the administration of ca- 
lomel. What proves that this is really the case, is, that, when 
the protochloride of mercury does not purge, but is retained 
for a long time in the digestive tube, it excites an unu- 
sual secretion from the salivary glands, and this on ac- 
count of the large quantity of corrosive sublimate which is 
