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PHARMACEUTICAL NOTICES, ETC, 
PHARMACEUTICAL NOTICES— CIRCULATORY DISPLACEMENT. 
By Joseph Laidley, of Richmond, Yirginia. 
Circulatory displacement was brought to the notice of American 
pharmaceutists several years ago, through Mr. Alsop,* of London, 
as applicable in the preparation of infusions; subsequently Dr. 
Benton suggested the feasibility of applying the same principle in 
preparing tinctures ;f but the process is so little resorted to by our 
profession, that I would again call attention to it. 
It possesses no advantage over percolation, where this process 
can be employed ; there are some substances, however, which can- 
not easily be exhausted of their soluble matters by percolation 
alone, it is for these that circulatory displacement is especially 
applicable. 
Professor Procter has already pointed out the advantages it af- 
fords in dissolving salts, especially those that undergo change 
when submitted to the prolonged action of the atmosphere and 
heat, as, for instance, protosulphate of iron.| 
The gum for syrup of gum arabic may be very rapidly dissolved 
without heat in this way. It is only necessary to tie the gum in a 
bag made of gauze, cambric, or some similar fabric, and suspend 
it just below the surface of the water contained in a specie jar. 
On a recent occasion I arranged, on the night of Saturday, 16 oz. 
(Troy) of gum in half a gallon of water, and on examining it early 
on the following Monday morning the gum was all dissolved. 
This process may be advantageously employed in dissolving 
sugar in preparing syrups ; especially for those where a high tem- 
perature is injurious, as in some of the syrups of fruits, I have em- 
ployed it very successfully. It has also the advantage of obvia- 
ting the scratching of the sides and bottom of the syrup pan, so 
often produced by the sugar when rubbed against them by the 
stirrer. When preparing syrups in this way the kettle should be 
tall, and of small diameter — tinned iron answers well — the sugar, 
in grains or crushed, should be suspended at the surface of the 
liquid in a coarse flannel bag, secured at the top to a strong hoop. 
* Am. Joum. Ph., viii. 89. 
•J- Mohr, Redwood and Procter's Pharmacy, pp. 238 and 267. 
J Am. Journ. Ph., xvi. 313. 
