66 PREPARATION OF MERCURIAL OINTMENT. 
be surprised at the possibility of causing, in a few minutes^ 
large quantities of metal to disappear in a small proportion 
of rancid grease. 
This being enunciated, I arrive at the facts, which 
prove it ; and I will content myself with purely and 
simply relating them. 
I for some months exposed to the contact of humid air 
about a pound of that fat, of little consistence, sold by the 
pork butchers. When I employed it, it was not hard, but 
it adhered tenaciously to the fingers. I took 200 grammes 
of it, and I triturated it for a few minutes in a marble mor- 
tar ; it became as soft and as thick as honey. I poured into 
it four pounds of mercury, by portions of 300 grammes at 
a time, and five minutes sufficed for the complete extinc- 
tion of the metal ; only after having introduced the fourth 
portion, the ointment had acquired hardness ; but the opera- 
tion could easily be continued by the addition of a little oil 
of sweet almonds. 
By operating as I have just said, I was able to incorpo- 
rate four pounds of mercury in the 200 grammes of fatty 
substance employed. The microscope detected not the 
smallest metallic particle in the whole mass. Arrived at 
this point, I added the 1,800 grammes of fresh lard, half 
melted, and, after a quarter of an hour's agitation I had a 
perfectly homogeneous ointment, in which the mercury was 
irreproachably extinguished. 
[The process described by M. Fossembas is not very 
new, as he himself acknowledges ; but it succeeds very well. 
It is analogous to the method of MM. Coldefy and Simonin, 
which consists, as is known, in extinguishing mercury by 
means of a small quantity of lard, which has been prepared 
by melting it, pouring it into water, and exposing it to the 
action of the air.] — Ibid, from Journ. de Pharm. 
