762 
PHARMACEUTICAL MEETING. 
pharmacists should endeavour to ascertain what was intended by physicians ; 
the prescriber in this case could not have desired to take a cast of his patient’s 
stomach. 
COMPOUND OINTMENT OF MERCURY. 
BY A. W. GERRARD. 
At the March meeting of the Society I made some remarks concerning a 
difficulty I had experienced in making the above ointment; since then I have 
made a few experiments with it, and the following are the results:— 
I first followed the Pharmacopoeia instructions, taking the quantities there 
expressed, and, as a result, obtained a mixture of undissolved wax, and particles 
of camphor mixed with the ointment of mercury, and oil, unfit to be called an 
ointment. 
The cause of the fault lies in the directions for making, which tell us to melt 
the wax with a gentle heat, and add the oil, then, when the mixture is nearly cold, 
add the camphor in powder and ointment of mercury. Now, on adding the wax 
and oil together, the oil being cold, a portion of the wax becomes hardened, and is 
not redissolved on stirring, so it is necessary to use further heat, redissolving 
the wax and oil, and then adding the camphor and ointment of mercury. 
This answers very well for the quantity ordered in the Pharmacopoeia, but in 
making larger quantities I have found it necessary, owing to. the difficulty of 
powdering large quantities of camphor, to keep the wax and oil at its melting- 
point some time after adding the other ingredients; this helps to dissolve any 
coarse particles of camphor. 
Some loss of camphor occurs by volatilization, but much of this may be pre¬ 
vented by making it in a jar with a close-fitting tin lid, having a hole cut in its 
centre for the insertion of a rod to stir it with. 
In conclusion, I would suggest that the Pharmacopoeia directions be altered, 
so that the wax and oil be melted together, the powdered camphor and ointment 
of mercury added, and the mixture kept at its melting-point till well mixed, 
then stir till cold, keeping the vessel well covered. 
OINTMENT OF TURPENTINE. 
4 
BY A. W. GERRARD. 
The ingredients of this ointment are oil of turpentine, resin, yellow wax, and 
lard. The Pharmacopoeia directs us to melt these ingredients together by the 
heat of a steam or water-bath, remove the vessel and stir the mixture constantly 
while it cools. 
If we examine the formula, we find that one of the ingredients is a volatile 
oil • and it struck me, that in making the ointment according to the Pharma¬ 
copoeia, a loss of a portion of this would occur, so with the object of testing 
this I made a few experiments, the results of which are as follows:— 
I operated upon the quantity of ingredients mentioned in the Pharmacopoeia, 
weighing the resin, wax, and lard, and measuring the turpentine. I then 
weighed"the whole of the ingredients together, which gave a total of 887 grains-; 
I then melted them by the heat of a steam-bath, stirring till cold, the result¬ 
ing ointment weighed 720 grains, thus a loss having occurred of 167 grains, or 
about three drachms by measure of turpentine. 
I again prepared the ointment, this time first melting the resin, wax, and 
lard together, and removing it from the heat, then added the turpentine, stirring 
till cold ; on weighing this a loss of 40 grains had occurred, or a saving of 127 
grains above the Pharmacopoeia process. This ointment was much too thin, 
so I prepared another quantity, adding 30 grains of resin and a quarter of an 
