PROCEEDINGS OF SECTION B. 
284 * 
too tenaciously, and did not allow it to evaporate on the skin; so to 
make an effective cooling ointment, the wool fat should he mixed 
with oil, lard, or soft paraffin before the water is added. In mixing 
wool fat with soft paraffin, &c., without heat, the soft paraffin should 
be added gradually to the wool fat; otherwise there is some trouble in 
mixing them. I hope the revisors of the Pharmacopoeia will not order 
the use of this basis for any but those few ointments where the old 
one is unsatisfactory. 1 admit that wool fat is very useful when it is 
desired to incorporate a liquid in an ointment ; but how often is this 
required? The price also of wool fat would be against its being used 
universally, for, although cost does not influence us, yet to substitute 
an expensive article when the one in common use is just as good is 
not desirable. 
In ointments, like other things, it is necessary to prove them for 
yourself. I made an ointment a few months ago of yellow oxide of 
mercury and lanolin ointment base ; I thought it was sure to mix 
all right, as the reports all speak of the suitableness of this article 
for all chemicals that are unstable when mixed with other substances. 
For a few weeks I had no complaints ; then I had it returned, as it 
caused a lot of irritation each time it was applied, which it did not at 
first, and I was rather surprised to find that all the yellow colour 
had disappeared. I do not know the cause of the change ; but if it 
acts as a reducing agent in this case, why not in another ? I also 
mixed some more with the same result. 
Lard properly benzoated, although it is spoken of disparagingly, 
is hard to improve upon, and I think it deserves to still retain its 
place as the base of the majority of the ointments of the Pharma- 
copoeia. In our summer it is rather soft, but this is easily overcome 
by adding beeswax. Very often the reason we give it a bad name 
for keeping is that we do not get the lard perfectly fresh, and 
benzoate it at once ; and then very often we do not take the trouble 
to do it properly. Some recommend solutions of gum benzoin in spirit 
for the purpose, as saving much trouble. I have never seen so 
good an article made this way, because the spirit dissolves a great 
deal more of the colouring matter of the gum and imparts it to the 
finished product, which has also not anything like such a good aroma as 
it has when made by the official formula. The directions for making 
would be improved by adopting the U.S.P. method of loosely enclos- 
ing the gum in a coarse muslin bag, which is then suspended in the 
melted fat; if working with a large quantity, it w r ould seem advisable 
to have the gum in, perhaps, tw r o or three bags according to the size of 
the vessel. This I think a great improvement on just putting the 
gum in the lard, for it invariably cakes into a hard mass at the bottom, 
and is with great difficulty stirred, which, if not done properly, does 
not give the lard a chance of dissolving as much of the benzoin as is 
necessary to make a good preparation, and things that are a trouble 
are very often shirked. There are two important items to be attended 
to in making a good article : They are (1) that the heat should not be 
too great, otherwise the aroma is destroyed ; and (2) that the benzoated 
lard should he stirred while it is cooling, for if anything but a small 
quantity is being made it granulates. The reason lard granulates after 
keeping is that, if the temperature rises enough to partly melt it, the 
