PHARMACY AT THE DUBLIN EXHIBITION. 
105 
medicinal value and convenient for manipulation, would be obtained. If such 
a plan as is here suggested should be available at all, it would, of course, be most 
successful in the very cases in which it would be most valuable—that is, with ex¬ 
tracts which are usually prescribed in small doses. It will, of course, be re¬ 
membered that we have in the pepsine powder of commerce an example of the 
same principle. 
Mr. J. W. Hart, London (53), deserves much credit for the very instructive 
series of specimens illustrative of the manufacture of isinglass which he exhi¬ 
bits. The officials to whom the arrangement of the contents of the Exhibition 
were entrusted seem to have been guided rather by the aspect of the glass cases 
containing the products than by the excellence or importance of the specimens 
themselves. Mr. Ilart has therefore to seek in the circumstance that he has 
covered his isinglass with a very unpretending case, an explanation of the fact 
that he has been allotted one of the very worst places in the whole building. 
M hen, however, the case has been discovered, its contents well repay inspection. 
They consist of a series of specimens of the different varieties of isinglass which 
find their way into commerce ; thus, we have of leaf isinglass the Hudson's 
Bay, the Samovey and the Astracan , and of other forms the Brazil Lump, 
Siberian Purse, and Samovey Boole. So far for the manufactured article. 
Then follow illustrations of the manufacture, which, by the way, include some 
very good and clear photographs of the machinery employed in this industry. 
The same weight—four ounces—of Russian isinglass is shown first as a sheet 
eight inches square by one-eighth of an inch thick, and then cut into the fami¬ 
liar u shreds,” of which we learn that this quarter of a pound contains no less 
a number than 50,000, and which would, if laid in a continuous line, measure 
12,700 yards. Several qualities of cut Russian isinglass are exhibited, from 
brown to nearly quite white, but it is not stated whether the difference is pro¬ 
duced by the action of any bleaching agent. 
There is a very ingenious contrivance shown in class D (80) by Mr. S. Bourne 
which is worthy of notice, as I can easily imagine many cases in which a modi¬ 
fication of it might be turned to account by the pharmaceutist. The invention 
has for its object the preservation of liquids which are liable to be injured by 
exposure to the air, and is especially intended to be applied to casks used for 
containing beer, or wines which, like claret, are of low alcoholic strength. As 
applied to a cask, it consists of, in the words of the patentee, “ a thin membrane, 
which divides the interior into two separate chambers, the lower of which con¬ 
tains the liquid, while the upper is filled with air that enters as the fluid is 
drawn off. It is so constructed as to adapt itself to the shape of one half of the 
vessel, to the centre of the sides of which its edges are attached, so as to form 
an air- and water-tight junction, and to have free motion either upwards or 
downwards.” I do not know whether this is of itself an intelligible description, 
but when illustrated by the models in the Exhibition it is perfectly lucid. The 
arrangement, as shown, is simply this:—A cask, placed in the position which 
it usually occupies when in use, is divided into two equal portions by a thin 
sheet of caoutchouc, which is inserted between the staves. When the cask is full, 
the india-rubber of course is in contact with its superior parietes ; as the liquid 
contents are drawn off it floats upon the surface, and without doubt excludes 
air. I need not here enter into the question of the practicability of employing 
an arrangement of this nature on the large scale, bat I think, as I said before, 
that it is suggestive. Mr. Bourne himself says that it affords to chemists and 
druggists “ the means of keeping ready for immediate use many infusions, solu¬ 
tions, and other preparations which involve delay in making on each separate 
occasion.” 
In Section X. (A, Xo. 300) Messrs. Spencer and Son, Dublin, show, together 
with other philosophical instruments of excellent workmanship, the new 
YOL. VII. I 
