NOTE ON DISPENSING. 
643 
and will not enter into the discussion, whether a gum, tragacanth or bassorin, 
exists or not, to which the formula C 13 H 10 O 10 should be assigned. Perhaps all 
the various kinds of these bodies may be referred to one and the same formula. 
The African tragacanth at least corresponds rather in this respect with gum 
arabic. 
From the experiments here detailed I infer, that the African Sterculia-traga¬ 
canth may be used both in pharmacy and in the arts instead of the usual drug 
of Asia Minor. When the Niger and its tributaries are opened to trade, this 
gum may possibly form an important item of exportation. 
A NEW BELLADONNA PLASTER. 
TO THE EDITORS OF THE PHARMACEUTICAL JOURNAL. 
Gentlemen,—Your correspondent, Mr. Gissing, in the last number, asks for 
certain information relative to the extract of belladonna now in use for making 
the emplastrum belladonnse of the British Pharmacopoeia, which I am not able 
to give; but, as belladonna plaster has for some time occupied my attention, it 
may, perhaps, interest Mr. Gissing, or other of your readers, to know how 
much better a plaster can be produced by the use of resinous extract of bella¬ 
donna root than that made with the spirituous extract of the leaf. 
Instead of the dark, nasty preparation of the Pharmacopoeia, I obtain a 
beautiful plaster, somewhat resembling empl. cerat. sapon., which adheres very 
nicely, requiring no adhesive margin, neither does it run nor exude, so that it 
may be worn a month or longer without staining the linen or producing any 
discomfort whatever. 
When this plaster is made with a third of its weight of pure extract, it is 
remarkably soothing, and, judging by my own experience, I think it promotes 
quiet and refreshing sleep. 
I am not aware that the extract of the root has ever been used in this way 
before, but I think it must commend itself to every pharmacist, as, besides being 
cleaner, the root is always more to be relied on for medicinal activity than any 
other part of the plant. 
I am, gentlemen, yours respectfully, 
John Balmer. 
205, St. John Street Road , London , E.C., April 20, 1869. 
NOTE ON DISPENSING. 
A recipe, the main ingredients of which were as follows, was directed to be 
prepared:— 
Potass. Chlorat. 5 ss. 
Sodae Hypophosphit. 33 . 
Syrup. Simpl. ^ss. 
Aquae ad £vj. 
The salts, owing to pressure with regard to time, were mixed energetically 
together in a mortar. Explosion ensued with no other dangerous result than 
whirling the pestle to a distance, and slightly injuring the dispenser. The 
mode of compounding this and similar formulae is to dissolve the salts separately, 
when no accident can happen. 
